Mercurial > hg > toybox
changeset 64:67ee3a0b76e1
In bunzip replace setjmp/longjmp handling with error_exit(), replace string
based handling of a 6-byte header with with two 24-bit integer reads. Use
xmalloc() and xzalloc().
| author | Rob Landley <rob@landley.net> |
|---|---|
| date | Thu, 18 Jan 2007 22:00:12 -0500 |
| parents | 69efffcacd70 |
| children | 329e2b37d0e1 |
| files | lib/bunzip.c lib/lib.h toys/bzcat.c |
| diffstat | 3 files changed, 17 insertions(+), 37 deletions(-) [+] |
line wrap: on
line diff
--- a/lib/bunzip.c Thu Jan 18 21:54:08 2007 -0500 +++ b/lib/bunzip.c Thu Jan 18 22:00:12 2007 -0500 @@ -27,18 +27,12 @@ #define RETVAL_OK 0 #define RETVAL_LAST_BLOCK (-1) #define RETVAL_NOT_BZIP_DATA (-2) -#define RETVAL_UNEXPECTED_INPUT_EOF (-3) -#define RETVAL_UNEXPECTED_OUTPUT_EOF (-4) -#define RETVAL_DATA_ERROR (-5) -#define RETVAL_OUT_OF_MEMORY (-6) -#define RETVAL_OBSOLETE_INPUT (-7) +#define RETVAL_DATA_ERROR (-3) +#define RETVAL_OBSOLETE_INPUT (-4) char *bunzip_errors[]={ NULL, - "Bad file checksum", "Not bzip data", - "Unexpected input EOF", - "Unexpected output EOF", "Data error", "Out of memory", "Obsolete (pre 0.9.5) bzip format not supported." @@ -54,9 +48,6 @@ // memory that persists between calls to bunzip typedef struct { - // For I/O error handling - jmp_buf jmpbuf; - // Input stream, input buffer, input bit buffer int in_fd, inbufCount, inbufPos; char *inbuf; @@ -93,7 +84,7 @@ // If we need to read more data from file into byte buffer, do so if (bd->inbufPos == bd->inbufCount) { if (0 >= (bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE))) - longjmp(bd->jmpbuf, RETVAL_UNEXPECTED_INPUT_EOF); + error_exit("Unexpected input EOF"); bd->inbufPos = 0; } @@ -128,20 +119,16 @@ char uc, mtfSymbol[256], symToByte[256], *selectors; unsigned int *dbuf; - // Read in header signature (borrowing mtfSymbol for temp space). - for (i=0; i<6; i++) mtfSymbol[i] = get_bits(bd,8); - mtfSymbol[6] = 0; - - // Read CRC (which is stored big endian). + // Read in header signature and CRC (which is stored big endian) + i = get_bits(bd, 24); + j = get_bits(bd, 24); bd->headerCRC = get_bits(bd,32); - // Is this the last block (with CRC for file)? - if (!strcmp(mtfSymbol, "\x17\x72\x45\x38\x50\x90")) - return RETVAL_LAST_BLOCK; + // Is this the EOF block with CRC for whole file? + if (i==0x177245 && j==0x385090) return RETVAL_LAST_BLOCK; - // If it's not a valid data block, barf. - if (strcmp(mtfSymbol, "\x31\x41\x59\x26\x53\x59")) - return RETVAL_NOT_BZIP_DATA; + // Is this a valid data block? + if (i!=0x314159 || j!=0x265359) return RETVAL_NOT_BZIP_DATA; dbuf = bd->dbuf; dbufSize = bd->dbufSize; @@ -414,7 +401,7 @@ { if (bd->outbufPos) { if (write(out_fd, bd->outbuf, bd->outbufPos) != bd->outbufPos) - longjmp(bd->jmpbuf,RETVAL_UNEXPECTED_OUTPUT_EOF); + error_exit("Unexpected output EOF"); bd->outbufPos = 0; } } @@ -526,8 +513,7 @@ if (!len) i += IOBUF_SIZE; // Allocate bunzip_data. Most fields initialize to zero. - if (!(bd = *bdp = malloc(i))) return RETVAL_OUT_OF_MEMORY; - memset(bd,0,sizeof(bunzip_data)); + bd = *bdp = xzalloc(i); if (len) { bd->inbuf = inbuf; bd->inbufCount = len; @@ -545,10 +531,6 @@ bd->crc32Table[i] = c; } - // Setup for I/O error handling via longjmp. - i = setjmp(bd->jmpbuf); - if (i) return i; - // Ensure that file starts with "BZh". for (i=0;i<3;i++) if (get_bits(bd,8)!="BZh"[i]) return RETVAL_NOT_BZIP_DATA; @@ -558,15 +540,14 @@ i = get_bits(bd, 8); if (i<'1' || i>'9') return RETVAL_NOT_BZIP_DATA; bd->dbufSize = 100000*(i-'0'); - if (!(bd->dbuf = malloc(bd->dbufSize * sizeof(int)))) - return RETVAL_OUT_OF_MEMORY; + bd->dbuf = xmalloc(bd->dbufSize * sizeof(int)); return RETVAL_OK; } // Example usage: decompress src_fd to dst_fd. (Stops at end of bzip data, // not end of file.) -char *bunzipStream(int src_fd, int dst_fd) +void bunzipStream(int src_fd, int dst_fd) { bunzip_data *bd; int i; @@ -578,5 +559,5 @@ flush_bunzip_outbuf(bd,dst_fd); free(bd->dbuf); free(bd); - return bunzip_errors[-i]; + if (i) error_exit(bunzip_errors[-i]); }