toybox: toys/other/bzcat.c annotate

annotate toys/other/bzcat.c @ 1746:b11f536bac74 draft

install -D bugfix from David Halls. (I tweaked some comment text while I was there.)

author	Rob Landley <rob@landley.net>
date	Sat, 21 Mar 2015 15:49:38 -0500
parents	c08555a9d948
children

rev	line source
694 786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	1 /* bzcat.c - decompress stdin to stdout using bunzip2.
233 d4176f3f3835 Zap toys/Config.in and instead create generated/Config.in from contents of Rob Landley <rob@landley.net> parents: 186 diff changeset	2 *
1197 c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	3 * Copyright 2003, 2007 Rob Landley <rob@landley.net>
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	4 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	5 * Based on a close reading (but not the actual code) of the original bzip2
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	6 * decompression code by Julian R Seward (jseward@acm.org), which also
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	7 * acknowledges contributions by Mike Burrows, David Wheeler, Peter Fenwick,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	8 * Alistair Moffat, Radford Neal, Ian H. Witten, Robert Sedgewick, and
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	9 * Jon L. Bentley.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	10 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	11 * No standard.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	12
233 d4176f3f3835 Zap toys/Config.in and instead create generated/Config.in from contents of Rob Landley <rob@landley.net> parents: 186 diff changeset	13
234 163498bf547b Move NEWTOY() list from end of toylist.h to generated/newtoys.h. Rob Landley <rob@landley.net> parents: 233 diff changeset	14 USE_BZCAT(NEWTOY(bzcat, NULL, TOYFLAG_USR\|TOYFLAG_BIN))
163498bf547b Move NEWTOY() list from end of toylist.h to generated/newtoys.h. Rob Landley <rob@landley.net> parents: 233 diff changeset	15
233 d4176f3f3835 Zap toys/Config.in and instead create generated/Config.in from contents of Rob Landley <rob@landley.net> parents: 186 diff changeset	16 config BZCAT
694 786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	17 bool "bzcat"
786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	18 default y
786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	19 help
786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	20 usage: bzcat [filename...]
233 d4176f3f3835 Zap toys/Config.in and instead create generated/Config.in from contents of Rob Landley <rob@landley.net> parents: 186 diff changeset	21
694 786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	22 Decompress listed files to stdout. Use stdin if no files listed.
233 d4176f3f3835 Zap toys/Config.in and instead create generated/Config.in from contents of Rob Landley <rob@landley.net> parents: 186 diff changeset	23 */
54 60a7fb8ddeb4 Add a quick and dirt bzcat (stdin to stdout only for the moment) to test Rob Landley <rob@landley.net> parents: diff changeset	24
60a7fb8ddeb4 Add a quick and dirt bzcat (stdin to stdout only for the moment) to test Rob Landley <rob@landley.net> parents: diff changeset	25 #include "toys.h"
60a7fb8ddeb4 Add a quick and dirt bzcat (stdin to stdout only for the moment) to test Rob Landley <rob@landley.net> parents: diff changeset	26
1197 c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	27 #define THREADS 1
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	28
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	29 // Constants for huffman coding
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	30 #define MAX_GROUPS 6
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	31 #define GROUP_SIZE 50 /* 64 would have been more efficient */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	32 #define MAX_HUFCODE_BITS 20 /* Longest huffman code allowed */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	33 #define MAX_SYMBOLS 258 /* 256 literals + RUNA + RUNB */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	34 #define SYMBOL_RUNA 0
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	35 #define SYMBOL_RUNB 1
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	36
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	37 // Other housekeeping constants
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	38 #define IOBUF_SIZE 4096
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	39
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	40 // Status return values
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	41 #define RETVAL_LAST_BLOCK (-100)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	42 #define RETVAL_NOT_BZIP_DATA (-1)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	43 #define RETVAL_DATA_ERROR (-2)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	44 #define RETVAL_OBSOLETE_INPUT (-3)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	45
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	46 // This is what we know about each huffman coding group
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	47 struct group_data {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	48 int limit[MAX_HUFCODE_BITS+1], base[MAX_HUFCODE_BITS], permute[MAX_SYMBOLS];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	49 char minLen, maxLen;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	50 };
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	51
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	52 // Data for burrows wheeler transform
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	53
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	54 struct bwdata {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	55 unsigned int origPtr;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	56 int byteCount[256];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	57 // State saved when interrupting output
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	58 int writePos, writeRun, writeCount, writeCurrent;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	59 unsigned int dataCRC, headerCRC;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	60 unsigned int *dbuf;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	61 };
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	62
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	63 // Structure holding all the housekeeping data, including IO buffers and
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	64 // memory that persists between calls to bunzip
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	65 struct bunzip_data {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	66 // Input stream, input buffer, input bit buffer
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	67 int in_fd, inbufCount, inbufPos;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	68 char *inbuf;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	69 unsigned int inbufBitCount, inbufBits;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	70
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	71 // Output buffer
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	72 char outbuf[IOBUF_SIZE];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	73 int outbufPos;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	74
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	75 unsigned int totalCRC;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	76
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	77 // First pass decompression data (Huffman and MTF decoding)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	78 char selectors[32768]; // nSelectors=15 bits
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	79 struct group_data groups[MAX_GROUPS]; // huffman coding tables
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	80 int symTotal, groupCount, nSelectors;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	81 unsigned char symToByte[256], mtfSymbol[256];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	82
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	83 // The CRC values stored in the block header and calculated from the data
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	84 unsigned int crc32Table[256];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	85
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	86 // Second pass decompression data (burrows-wheeler transform)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	87 unsigned int dbufSize;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	88 struct bwdata bwdata[THREADS];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	89 };
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	90
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	91 // Return the next nnn bits of input. All reads from the compressed input
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	92 // are done through this function. All reads are big endian.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	93 static unsigned int get_bits(struct bunzip_data *bd, char bits_wanted)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	94 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	95 unsigned int bits = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	96
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	97 // If we need to get more data from the byte buffer, do so. (Loop getting
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	98 // one byte at a time to enforce endianness and avoid unaligned access.)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	99 while (bd->inbufBitCount < bits_wanted) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	100
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	101 // If we need to read more data from file into byte buffer, do so
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	102 if (bd->inbufPos == bd->inbufCount) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	103 if (0 >= (bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE)))
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	104 error_exit("input EOF");
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	105 bd->inbufPos = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	106 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	107
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	108 // Avoid 32-bit overflow (dump bit buffer to top of output)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	109 if (bd->inbufBitCount>=24) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	110 bits = bd->inbufBits&((1<<bd->inbufBitCount)-1);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	111 bits_wanted -= bd->inbufBitCount;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	112 bits <<= bits_wanted;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	113 bd->inbufBitCount = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	114 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	115
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	116 // Grab next 8 bits of input from buffer.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	117 bd->inbufBits = (bd->inbufBits<<8) \| bd->inbuf[bd->inbufPos++];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	118 bd->inbufBitCount += 8;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	119 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	120
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	121 // Calculate result
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	122 bd->inbufBitCount -= bits_wanted;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	123 bits \|= (bd->inbufBits>>bd->inbufBitCount) & ((1<<bits_wanted)-1);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	124
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	125 return bits;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	126 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	127
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	128 /* Read block header at start of a new compressed data block. Consists of:
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	129 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	130 * 48 bits : Block signature, either pi (data block) or e (EOF block).
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	131 * 32 bits : bw->headerCRC
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	132 * 1 bit : obsolete feature flag.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	133 * 24 bits : origPtr (Burrows-wheeler unwind index, only 20 bits ever used)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	134 * 16 bits : Mapping table index.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	135 *[16 bits]: symToByte[symTotal] (Mapping table. For each bit set in mapping
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	136 * table index above, read another 16 bits of mapping table data.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	137 * If correspondig bit is unset, all bits in that mapping table
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	138 * section are 0.)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	139 * 3 bits : groupCount (how many huffman tables used to encode, anywhere
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	140 * from 2 to MAX_GROUPS)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	141 * variable: hufGroup[groupCount] (MTF encoded huffman table data.)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	142 */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	143
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	144 static int read_block_header(struct bunzip_data bd, struct bwdata bw)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	145 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	146 struct group_data *hufGroup;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	147 int hh, ii, jj, kk, symCount, base, limit;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	148 unsigned char uc;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	149
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	150 // Read in header signature and CRC (which is stored big endian)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	151 ii = get_bits(bd, 24);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	152 jj = get_bits(bd, 24);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	153 bw->headerCRC = get_bits(bd,32);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	154
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	155 // Is this the EOF block with CRC for whole file? (Constant is "e")
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	156 if (ii==0x177245 && jj==0x385090) return RETVAL_LAST_BLOCK;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	157
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	158 // Is this a valid data block? (Constant is "pi".)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	159 if (ii!=0x314159 \|\| jj!=0x265359) return RETVAL_NOT_BZIP_DATA;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	160
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	161 // We can add support for blockRandomised if anybody complains.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	162 if (get_bits(bd,1)) return RETVAL_OBSOLETE_INPUT;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	163 if ((bw->origPtr = get_bits(bd,24)) > bd->dbufSize) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	164
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	165 // mapping table: if some byte values are never used (encoding things
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	166 // like ascii text), the compression code removes the gaps to have fewer
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	167 // symbols to deal with, and writes a sparse bitfield indicating which
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	168 // values were present. We make a translation table to convert the symbols
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	169 // back to the corresponding bytes.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	170 hh = get_bits(bd, 16);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	171 bd->symTotal = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	172 for (ii=0; ii<16; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	173 if (hh & (1 << (15 - ii))) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	174 kk = get_bits(bd, 16);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	175 for (jj=0; jj<16; jj++)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	176 if (kk & (1 << (15 - jj)))
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	177 bd->symToByte[bd->symTotal++] = (16 * ii) + jj;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	178 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	179 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	180
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	181 // How many different huffman coding groups does this block use?
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	182 bd->groupCount = get_bits(bd,3);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	183 if (bd->groupCount<2 \|\| bd->groupCount>MAX_GROUPS) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	184
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	185 // nSelectors: Every GROUP_SIZE many symbols we switch huffman coding
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	186 // tables. Each group has a selector, which is an index into the huffman
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	187 // coding table arrays.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	188 //
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	189 // Read in the group selector array, which is stored as MTF encoded
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	190 // bit runs. (MTF = Move To Front. Every time a symbol occurs it's moved
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	191 // to the front of the table, so it has a shorter encoding next time.)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	192 if (!(bd->nSelectors = get_bits(bd, 15))) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	193 for (ii=0; ii<bd->groupCount; ii++) bd->mtfSymbol[ii] = ii;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	194 for (ii=0; ii<bd->nSelectors; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	195
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	196 // Get next value
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	197 for(jj=0;get_bits(bd,1);jj++)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	198 if (jj>=bd->groupCount) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	199
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	200 // Decode MTF to get the next selector, and move it to the front.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	201 uc = bd->mtfSymbol[jj];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	202 memmove(bd->mtfSymbol+1, bd->mtfSymbol, jj);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	203 bd->mtfSymbol[0] = bd->selectors[ii] = uc;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	204 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	205
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	206 // Read the huffman coding tables for each group, which code for symTotal
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	207 // literal symbols, plus two run symbols (RUNA, RUNB)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	208 symCount = bd->symTotal+2;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	209 for (jj=0; jj<bd->groupCount; jj++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	210 unsigned char length[MAX_SYMBOLS];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	211 unsigned temp[MAX_HUFCODE_BITS+1];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	212 int minLen, maxLen, pp;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	213
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	214 // Read lengths
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	215 hh = get_bits(bd, 5);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	216 for (ii = 0; ii < symCount; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	217 for(;;) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	218 // !hh \|\| hh > MAX_HUFCODE_BITS in one test.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	219 if (MAX_HUFCODE_BITS-1 < (unsigned)hh-1) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	220 // Grab 2 bits instead of 1 (slightly smaller/faster). Stop if
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	221 // first bit is 0, otherwise second bit says whether to
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	222 // increment or decrement.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	223 kk = get_bits(bd, 2);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	224 if (kk & 2) hh += 1 - ((kk&1)<<1);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	225 else {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	226 bd->inbufBitCount++;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	227 break;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	228 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	229 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	230 length[ii] = hh;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	231 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	232
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	233 // Find largest and smallest lengths in this group
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	234 minLen = maxLen = length[0];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	235 for (ii = 1; ii < symCount; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	236 if(length[ii] > maxLen) maxLen = length[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	237 else if(length[ii] < minLen) minLen = length[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	238 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	239
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	240 /* Calculate permute[], base[], and limit[] tables from length[].
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	241 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	242 * permute[] is the lookup table for converting huffman coded symbols
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	243 * into decoded symbols. It contains symbol values sorted by length.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	244 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	245 * base[] is the amount to subtract from the value of a huffman symbol
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	246 * of a given length when using permute[].
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	247 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	248 * limit[] indicates the largest numerical value a symbol with a given
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	249 * number of bits can have. It lets us know when to stop reading.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	250 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	251 * To use these, keep reading bits until value <= limit[bitcount] or
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	252 * you've read over 20 bits (error). Then the decoded symbol
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	253 * equals permute[hufcode_value - base[hufcode_bitcount]].
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	254 */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	255 hufGroup = bd->groups+jj;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	256 hufGroup->minLen = minLen;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	257 hufGroup->maxLen = maxLen;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	258
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	259 // Note that minLen can't be smaller than 1, so we adjust the base
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	260 // and limit array pointers so we're not always wasting the first
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	261 // entry. We do this again when using them (during symbol decoding).
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	262 base = hufGroup->base-1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	263 limit = hufGroup->limit-1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	264
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	265 // zero temp[] and limit[], and calculate permute[]
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	266 pp = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	267 for (ii = minLen; ii <= maxLen; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	268 temp[ii] = limit[ii] = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	269 for (hh = 0; hh < symCount; hh++)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	270 if (length[hh] == ii) hufGroup->permute[pp++] = hh;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	271 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	272
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	273 // Count symbols coded for at each bit length
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	274 for (ii = 0; ii < symCount; ii++) temp[length[ii]]++;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	275
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	276 /* Calculate limit[] (the largest symbol-coding value at each bit
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	277 * length, which is (previous limit<<1)+symbols at this level), and
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	278 * base[] (number of symbols to ignore at each bit length, which is
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	279 * limit minus the cumulative count of symbols coded for already). */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	280 pp = hh = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	281 for (ii = minLen; ii < maxLen; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	282 pp += temp[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	283 limit[ii] = pp-1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	284 pp <<= 1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	285 base[ii+1] = pp-(hh+=temp[ii]);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	286 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	287 limit[maxLen] = pp+temp[maxLen]-1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	288 limit[maxLen+1] = INT_MAX;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	289 base[minLen] = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	290 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	291
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	292 return 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	293 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	294
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	295 /* First pass, read block's symbols into dbuf[dbufCount].
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	296 *
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	297 * This undoes three types of compression: huffman coding, run length encoding,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	298 * and move to front encoding. We have to undo all those to know when we've
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	299 * read enough input.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	300 */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	301
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	302 static int read_huffman_data(struct bunzip_data bd, struct bwdata bw)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	303 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	304 struct group_data *hufGroup;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	305 int hh, ii, jj, kk, runPos, dbufCount, symCount, selector, nextSym,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	306 byteCount, base, *limit;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	307 unsigned int *dbuf = bw->dbuf;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	308 unsigned char uc;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	309
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	310 // We've finished reading and digesting the block header. Now read this
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	311 // block's huffman coded symbols from the file and undo the huffman coding
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	312 // and run length encoding, saving the result into dbuf[dbufCount++] = uc
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	313
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	314 // Initialize symbol occurrence counters and symbol mtf table
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	315 byteCount = bw->byteCount;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	316 for(ii=0; ii<256; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	317 byteCount[ii] = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	318 bd->mtfSymbol[ii] = ii;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	319 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	320
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	321 // Loop through compressed symbols. This is the first "tight inner loop"
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	322 // that needs to be micro-optimized for speed. (This one fills out dbuf[]
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	323 // linearly, staying in cache more, so isn't as limited by DRAM access.)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	324 runPos = dbufCount = symCount = selector = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	325 // Some unnecessary initializations to shut gcc up.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	326 base = limit = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	327 hufGroup = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	328 hh = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	329
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	330 for (;;) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	331 // Have we reached the end of this huffman group?
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	332 if (!(symCount--)) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	333 // Determine which huffman coding group to use.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	334 symCount = GROUP_SIZE-1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	335 if (selector >= bd->nSelectors) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	336 hufGroup = bd->groups + bd->selectors[selector++];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	337 base = hufGroup->base-1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	338 limit = hufGroup->limit-1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	339 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	340
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	341 // Read next huffman-coded symbol (into jj).
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	342 ii = hufGroup->minLen;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	343 jj = get_bits(bd, ii);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	344 while (jj > limit[ii]) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	345 // if (ii > hufGroup->maxLen) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	346 ii++;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	347
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	348 // Unroll get_bits() to avoid a function call when the data's in
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	349 // the buffer already.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	350 kk = bd->inbufBitCount
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	351 ? (bd->inbufBits >> --(bd->inbufBitCount)) & 1 : get_bits(bd, 1);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	352 jj = (jj << 1) \| kk;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	353 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	354 // Huffman decode jj into nextSym (with bounds checking)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	355 jj-=base[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	356
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	357 if (ii > hufGroup->maxLen \|\| (unsigned)jj >= MAX_SYMBOLS)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	358 return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	359 nextSym = hufGroup->permute[jj];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	360
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	361 // If this is a repeated run, loop collecting data
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	362 if ((unsigned)nextSym <= SYMBOL_RUNB) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	363 // If this is the start of a new run, zero out counter
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	364 if(!runPos) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	365 runPos = 1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	366 hh = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	367 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	368
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	369 /* Neat trick that saves 1 symbol: instead of or-ing 0 or 1 at
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	370 each bit position, add 1 or 2 instead. For example,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	371 1011 is 1<<0 + 1<<1 + 2<<2. 1010 is 2<<0 + 2<<1 + 1<<2.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	372 You can make any bit pattern that way using 1 less symbol than
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	373 the basic or 0/1 method (except all bits 0, which would use no
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	374 symbols, but a run of length 0 doesn't mean anything in this
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	375 context). Thus space is saved. */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	376 hh += (runPos << nextSym); // +runPos if RUNA; +2*runPos if RUNB
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	377 runPos <<= 1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	378 continue;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	379 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	380
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	381 /* When we hit the first non-run symbol after a run, we now know
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	382 how many times to repeat the last literal, so append that many
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	383 copies to our buffer of decoded symbols (dbuf) now. (The last
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	384 literal used is the one at the head of the mtfSymbol array.) */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	385 if (runPos) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	386 runPos = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	387 if (dbufCount+hh > bd->dbufSize) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	388
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	389 uc = bd->symToByte[bd->mtfSymbol[0]];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	390 byteCount[uc] += hh;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	391 while (hh--) dbuf[dbufCount++] = uc;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	392 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	393
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	394 // Is this the terminating symbol?
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	395 if (nextSym>bd->symTotal) break;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	396
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	397 /* At this point, the symbol we just decoded indicates a new literal
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	398 character. Subtract one to get the position in the MTF array
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	399 at which this literal is currently to be found. (Note that the
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	400 result can't be -1 or 0, because 0 and 1 are RUNA and RUNB.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	401 Another instance of the first symbol in the mtf array, position 0,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	402 would have been handled as part of a run.) */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	403 if (dbufCount>=bd->dbufSize) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	404 ii = nextSym - 1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	405 uc = bd->mtfSymbol[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	406 // On my laptop, unrolling this memmove() into a loop shaves 3.5% off
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	407 // the total running time.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	408 while(ii--) bd->mtfSymbol[ii+1] = bd->mtfSymbol[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	409 bd->mtfSymbol[0] = uc;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	410 uc = bd->symToByte[uc];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	411
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	412 // We have our literal byte. Save it into dbuf.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	413 byteCount[uc]++;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	414 dbuf[dbufCount++] = (unsigned int)uc;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	415 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	416
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	417 // Now we know what dbufCount is, do a better sanity check on origPtr.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	418 if (bw->origPtr >= (bw->writeCount = dbufCount)) return RETVAL_DATA_ERROR;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	419
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	420 return 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	421 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	422
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	423 // Flush output buffer to disk
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	424 void flush_bunzip_outbuf(struct bunzip_data *bd, int out_fd)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	425 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	426 if (bd->outbufPos) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	427 if (write(out_fd, bd->outbuf, bd->outbufPos) != bd->outbufPos)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	428 error_exit("output EOF");
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	429 bd->outbufPos = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	430 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	431 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	432
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	433 void burrows_wheeler_prep(struct bunzip_data bd, struct bwdata bw)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	434 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	435 int ii, jj;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	436 unsigned int *dbuf = bw->dbuf;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	437 int *byteCount = bw->byteCount;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	438
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	439 // Technically this part is preparation for the burrows-wheeler
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	440 // transform, but it's quick and convenient to do here.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	441
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	442 // Turn byteCount into cumulative occurrence counts of 0 to n-1.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	443 jj = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	444 for (ii=0; ii<256; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	445 int kk = jj + byteCount[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	446 byteCount[ii] = jj;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	447 jj = kk;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	448 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	449
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	450 // Use occurrence counts to quickly figure out what order dbuf would be in
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	451 // if we sorted it.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	452 for (ii=0; ii < bw->writeCount; ii++) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	453 unsigned char uc = dbuf[ii];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	454 dbuf[byteCount[uc]] \|= (ii << 8);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	455 byteCount[uc]++;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	456 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	457
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	458 // blockRandomised support would go here.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	459
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	460 // Using ii as position, jj as previous character, hh as current character,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	461 // and uc as run count.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	462 bw->dataCRC = 0xffffffffL;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	463
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	464 /* Decode first byte by hand to initialize "previous" byte. Note that it
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	465 doesn't get output, and if the first three characters are identical
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	466 it doesn't qualify as a run (hence uc=255, which will either wrap
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	467 to 1 or get reset). */
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	468 if (bw->writeCount) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	469 bw->writePos = dbuf[bw->origPtr];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	470 bw->writeCurrent = (unsigned char)bw->writePos;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	471 bw->writePos >>= 8;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	472 bw->writeRun = -1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	473 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	474 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	475
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	476 // Decompress a block of text to intermediate buffer
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	477 int read_bunzip_data(struct bunzip_data *bd)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	478 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	479 int rc = read_block_header(bd, bd->bwdata);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	480 if (!rc) rc=read_huffman_data(bd, bd->bwdata);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	481
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	482 // First thing that can be done by a background thread.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	483 burrows_wheeler_prep(bd, bd->bwdata);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	484
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	485 return rc;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	486 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	487
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	488 // Undo burrows-wheeler transform on intermediate buffer to produce output.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	489 // If !len, write up to len bytes of data to buf. Otherwise write to out_fd.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	490 // Returns len ? bytes written : 0. Notice all errors are negative #'s.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	491 //
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	492 // Burrows-wheeler transform is described at:
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	493 // http://dogma.net/markn/articles/bwt/bwt.htm
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	494 // http://marknelson.us/1996/09/01/bwt/
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	495
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	496 int write_bunzip_data(struct bunzip_data bd, struct bwdata bw, int out_fd, char *outbuf, int len)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	497 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	498 unsigned int *dbuf = bw->dbuf;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	499 int count, pos, current, run, copies, outbyte, previous, gotcount = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	500
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	501 for (;;) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	502 // If last read was short due to end of file, return last block now
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	503 if (bw->writeCount < 0) return bw->writeCount;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	504
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	505 // If we need to refill dbuf, do it.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	506 if (!bw->writeCount) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	507 int i = read_bunzip_data(bd);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	508 if (i) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	509 if (i == RETVAL_LAST_BLOCK) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	510 bw->writeCount = i;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	511 return gotcount;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	512 } else return i;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	513 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	514 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	515
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	516 // loop generating output
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	517 count = bw->writeCount;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	518 pos = bw->writePos;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	519 current = bw->writeCurrent;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	520 run = bw->writeRun;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	521 while (count) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	522
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	523 // If somebody (like tar) wants a certain number of bytes of
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	524 // data from memory instead of written to a file, humor them.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	525 if (len && bd->outbufPos >= len) goto dataus_interruptus;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	526 count--;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	527
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	528 // Follow sequence vector to undo Burrows-Wheeler transform.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	529 previous = current;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	530 pos = dbuf[pos];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	531 current = pos&0xff;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	532 pos >>= 8;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	533
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	534 // Whenever we see 3 consecutive copies of the same byte,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	535 // the 4th is a repeat count
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	536 if (run++ == 3) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	537 copies = current;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	538 outbyte = previous;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	539 current = -1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	540 } else {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	541 copies = 1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	542 outbyte = current;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	543 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	544
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	545 // Output bytes to buffer, flushing to file if necessary
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	546 while (copies--) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	547 if (bd->outbufPos == IOBUF_SIZE) flush_bunzip_outbuf(bd, out_fd);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	548 bd->outbuf[bd->outbufPos++] = outbyte;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	549 bw->dataCRC = (bw->dataCRC << 8)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	550 ^ bd->crc32Table[(bw->dataCRC >> 24) ^ outbyte];
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	551 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	552 if (current != previous) run=0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	553 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	554
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	555 // decompression of this block completed successfully
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	556 bw->dataCRC = ~(bw->dataCRC);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	557 bd->totalCRC = ((bd->totalCRC << 1) \| (bd->totalCRC >> 31)) ^ bw->dataCRC;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	558
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	559 // if this block had a crc error, force file level crc error.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	560 if (bw->dataCRC != bw->headerCRC) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	561 bd->totalCRC = bw->headerCRC+1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	562
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	563 return RETVAL_LAST_BLOCK;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	564 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	565 dataus_interruptus:
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	566 bw->writeCount = count;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	567 if (len) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	568 gotcount += bd->outbufPos;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	569 memcpy(outbuf, bd->outbuf, len);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	570
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	571 // If we got enough data, checkpoint loop state and return
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	572 if ((len -= bd->outbufPos)<1) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	573 bd->outbufPos -= len;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	574 if (bd->outbufPos) memmove(bd->outbuf, bd->outbuf+len, bd->outbufPos);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	575 bw->writePos = pos;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	576 bw->writeCurrent = current;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	577 bw->writeRun = run;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	578
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	579 return gotcount;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	580 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	581 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	582 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	583 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	584
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	585 // Allocate the structure, read file header. If !len, src_fd contains
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	586 // filehandle to read from. Else inbuf contains data.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	587 int start_bunzip(struct bunzip_data *bdp, int src_fd, char inbuf, int len)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	588 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	589 struct bunzip_data *bd;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	590 unsigned int i;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	591
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	592 // Figure out how much data to allocate.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	593 i = sizeof(struct bunzip_data);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	594 if (!len) i += IOBUF_SIZE;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	595
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	596 // Allocate bunzip_data. Most fields initialize to zero.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	597 bd = *bdp = xzalloc(i);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	598 if (len) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	599 bd->inbuf = inbuf;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	600 bd->inbufCount = len;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	601 bd->in_fd = -1;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	602 } else {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	603 bd->inbuf = (char *)(bd+1);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	604 bd->in_fd = src_fd;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	605 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	606
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	607 crc_init(bd->crc32Table, 0);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	608
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	609 // Ensure that file starts with "BZh".
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	610 for (i=0;i<3;i++) if (get_bits(bd,8)!="BZh"[i]) return RETVAL_NOT_BZIP_DATA;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	611
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	612 // Next byte ascii '1'-'9', indicates block size in units of 100k of
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	613 // uncompressed data. Allocate intermediate buffer for block.
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	614 i = get_bits(bd, 8);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	615 if (i<'1' \|\| i>'9') return RETVAL_NOT_BZIP_DATA;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	616 bd->dbufSize = 100000(i-'0')THREADS;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	617 for (i=0; i<THREADS; i++)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	618 bd->bwdata[i].dbuf = xmalloc(bd->dbufSize * sizeof(int));
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	619
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	620 return 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	621 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	622
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	623 // Example usage: decompress src_fd to dst_fd. (Stops at end of bzip data,
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	624 // not end of file.)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	625 void bunzipStream(int src_fd, int dst_fd)
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	626 {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	627 struct bunzip_data *bd;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	628 char *bunzip_errors[]={NULL, "not bzip", "bad data", "old format"};
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	629 int i, j;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	630
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	631 if (!(i = start_bunzip(&bd,src_fd, 0, 0))) {
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	632 i = write_bunzip_data(bd,bd->bwdata, dst_fd, 0, 0);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	633 if (i==RETVAL_LAST_BLOCK && bd->bwdata[0].headerCRC==bd->totalCRC) i = 0;
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	634 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	635 flush_bunzip_outbuf(bd, dst_fd);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	636
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	637 for (j=0; j<THREADS; j++) free(bd->bwdata[j].dbuf);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	638 free(bd);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	639 if (i) error_exit(bunzip_errors[-i]);
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	640 }
c08555a9d948 Move bunzip2 logic from lib into bzcat. Rob Landley <rob@landley.net> parents: 694 diff changeset	641
307 937148640ac5 Finish bzcat. Rob Landley <rob@landley.net> parents: 234 diff changeset	642 static void do_bzcat(int fd, char *name)
937148640ac5 Finish bzcat. Rob Landley <rob@landley.net> parents: 234 diff changeset	643 {
694 786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	644 bunzipStream(fd, 1);
307 937148640ac5 Finish bzcat. Rob Landley <rob@landley.net> parents: 234 diff changeset	645 }
937148640ac5 Finish bzcat. Rob Landley <rob@landley.net> parents: 234 diff changeset	646
186 25447caf1b4b Change command main() functions to return void, and exit(toys.exitval) from Rob Landley <rob@landley.net> parents: 64 diff changeset	647 void bzcat_main(void)
54 60a7fb8ddeb4 Add a quick and dirt bzcat (stdin to stdout only for the moment) to test Rob Landley <rob@landley.net> parents: diff changeset	648 {
694 786841fdb1e0 Reindent to two spaces per level. Remove vi: directives that haven't worked right in years (ubuntu broke its' vim implementation). Remove trailing spaces. Add/remove blank lines. Re-wordwrap in places. Update documentation with new coding style. Rob Landley <rob@landley.net> parents: 656 diff changeset	649 loopfiles(toys.optargs, do_bzcat);
54 60a7fb8ddeb4 Add a quick and dirt bzcat (stdin to stdout only for the moment) to test Rob Landley <rob@landley.net> parents: diff changeset	650 }

Mercurial > hg > toybox

annotate toys/other/bzcat.c @ 1746:b11f536bac74 draft