--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common/download_functions.sh	Sun Jul 03 17:23:26 2011 -0500
@@ -0,0 +1,265 @@
+#!/bin/echo "This file is sourced, not run"
+
+# Remove version information and extension tarball name "$1".
+# If "$2", add that version number back, keeping original extension.
+
+noversion()
+{
+  LOGRUS='s/-*\(\([0-9\.]\)*\([_-]rc\)*\(-pre\)*\([0-9][a-zA-Z]\)*\)*\(\.tar\(\..z2*\)*\)$'
+  [ -z "$2" ] && LOGRUS="$LOGRUS//" || LOGRUS="$LOGRUS/$2\\6/"
+
+  echo "$1" | sed -e "$LOGRUS"
+}
+
+# Apply any patches to this package
+patch_package()
+{
+  ls "$PATCHDIR/${PACKAGE}"-*.patch 2> /dev/null | sort | while read i
+  do
+    if [ -f "$i" ]
+    then
+      echo "Applying $i"
+      (cd "${SRCTREE}/${PACKAGE}" &&
+       patch -p1 -i "$i" &&
+       sha1file "$i" >> "$SHA1FILE") ||
+        ([ -z "$ALLOW_PATCH_FAILURE" ] && dienow)
+    fi
+  done
+}
+
+# Get the tarball for this package
+
+find_package_tarball()
+{
+  # If there are multiple similar files we want the newest timestamp, in case
+  # the URL just got upgraded but cleanup_oldfiles hasn't run yet.  Be able to
+  # distinguish "package-123.tar.bz2" from "package-tests-123.tar.bz2" and
+  # return the shorter one reliably.
+
+  ls -tc "$SRCDIR/$1-"*.tar* 2>/dev/null | while read i
+  do
+    if [ "$(noversion "${i/*\//}")" == "$1" ]
+    then
+      echo "$i"
+      break
+    fi
+  done
+}
+
+# Extract tarball named in $1 and apply all relevant patches into
+# "$BUILD/packages/$1".  Record sha1sum of tarball and patch files in
+# sha1-for-source.txt.  Re-extract if tarball or patches change.
+
+extract_package()
+{
+  mkdir -p "$SRCTREE" || dienow
+
+  # Figure out whether we're using an unstable package.
+
+  PACKAGE="$1"
+  is_in_list "$PACKAGE" $USE_UNSTABLE && PACKAGE=alt-"$PACKAGE"
+
+  # Announce to the world that we're cracking open a new package
+
+  announce "$PACKAGE"
+
+  # Find tarball, and determine type
+
+  FILENAME="$(find_package_tarball "$PACKAGE")"
+  DECOMPRESS=""
+  [ "$FILENAME" != "${FILENAME/%\.tar\.bz2/}" ] && DECOMPRESS="j"
+  [ "$FILENAME" != "${FILENAME/%\.tar\.gz/}" ] && DECOMPRESS="z"
+
+  # If the source tarball doesn't exist, but the extracted directory is there,
+  # assume everything's ok.
+
+  SHA1FILE="$SRCTREE/$PACKAGE/sha1-for-source.txt"
+  if [ -z "$FILENAME" ]
+  then
+    if [ ! -e "$SRCTREE/$PACKAGE" ]
+    then
+      echo "No tarball for $PACKAGE" >&2
+      dienow
+    fi
+
+    # If the sha1sum file isn't there, re-patch the package.
+    [ ! -e "$SHA1FILE" ] && patch_package
+    return 0
+  fi
+
+  # Check the sha1 list from the previous extract.  If the source is already
+  # up to date (including patches), keep it.
+
+  SHA1TAR="$(sha1file "$FILENAME")"
+  SHALIST=$(cat "$SHA1FILE" 2> /dev/null)
+  if [ ! -z "$SHALIST" ]
+  then
+    for i in "$SHA1TAR" $(sha1file "$PATCHDIR/$PACKAGE"-* 2>/dev/null)
+    do
+      # Is this sha1 in the file?
+      if [ -z "$(echo "$SHALIST" | sed -n "s/$i/$i/p" )" ]
+      then
+        SHALIST=missing
+        break
+      fi
+      # Remove it
+      SHALIST="$(echo "$SHALIST" | sed "s/$i//" )"
+    done
+    # If we matched all the sha1sums, nothing more to do.
+    [ -z "$SHALIST" ] && return 0
+  fi
+
+  # Re-extract the package, deleting the old one (if any)..
+
+  echo -n "Extracting '$PACKAGE'"
+  (
+    UNIQUE=$(readlink /proc/self)
+    trap 'rm -rf "$BUILD/temp-'$UNIQUE'"' EXIT
+    rm -rf "$SRCTREE/$PACKAGE" 2>/dev/null
+    mkdir -p "$BUILD/temp-$UNIQUE" "$SRCTREE" || dienow
+
+    { tar -xv${DECOMPRESS} -f "$FILENAME" -C "$BUILD/temp-$UNIQUE" || dienow
+    } | dotprogress
+
+    mv "$BUILD/temp-$UNIQUE/"* "$SRCTREE/$PACKAGE" &&
+    echo "$SHA1TAR" > "$SHA1FILE"
+  )
+
+  [ $? -ne 0 ] && dienow
+
+  patch_package
+}
+
+# Confirm that a file has the appropriate checksum (or exists but SHA1 is blank)
+# Delete invalid file.
+
+confirm_checksum()
+{
+  SUM="$(sha1file "$SRCDIR/$FILENAME" 2>/dev/null)"
+  if [ x"$SUM" == x"$SHA1" ] || [ -z "$SHA1" ] && [ -f "$SRCDIR/$FILENAME" ]
+  then
+    if [ -z "$SHA1" ]
+    then
+      echo "No SHA1 for $FILENAME ($SUM)"
+    else
+      echo "Confirmed $FILENAME"
+    fi
+
+    # Preemptively extract source packages?
+
+    [ -z "$EXTRACT_ALL" ] && return 0
+    extract_package "$BASENAME"
+    return $?
+  fi
+
+  # If there's a corrupted file, delete it.  In theory it would be nice
+  # to resume downloads, but wget creates "*.1" files instead.
+
+  rm "$SRCDIR/$FILENAME" 2> /dev/null
+
+  return 1
+}
+
+# Attempt to obtain file from a specific location
+
+download_from()
+{
+  # Return success if we already have a valid copy of the file
+
+  confirm_checksum && return 0
+
+  # If we have another source, try to download file from there.
+
+  [ -z "$1" ] && return 1
+  wget -t 2 -T 20 -O "$SRCDIR/$FILENAME" "$1" ||
+    (rm "$SRCDIR/$FILENAME"; return 2)
+  touch -c "$SRCDIR/$FILENAME"
+
+  confirm_checksum
+}
+
+# Confirm a file matches sha1sum, else try to download it from mirror list.
+
+download()
+{
+  FILENAME=`echo "$URL" | sed 's .*/  '`
+  [ -z "$RENAME" ] || FILENAME="$(echo "$FILENAME" | sed -r "$RENAME")"
+  ALTFILENAME=alt-"$(noversion "$FILENAME" -0)"
+
+  if [ -z "$(sha1sum < /dev/null)" ]
+  then
+    echo "Error: please install sha1sum" >&2
+    exit 1
+  fi
+
+  echo -ne "checking $FILENAME\r"
+
+  # Update timestamps on both stable and unstable tarballs (if any)
+  # so cleanup_oldfiles doesn't delete stable when we're building unstable
+  # or vice versa
+
+  touch -c "$SRCDIR"/{"$FILENAME","$ALTFILENAME"} 2>/dev/null
+
+  # Give package name, minus file's version number and archive extension.
+  BASENAME="$(noversion "$FILENAME")"
+
+  # If unstable version selected, try from listed location, and fall back
+  # to PREFERRED_MIRROR.  Do not try normal mirror locations for unstable.
+
+  if is_in_list "$BASENAME" $USE_UNSTABLE
+  then
+    # If extracted source directory exists, don't download alt-tarball.
+    [ -e "$SRCTREE/alt-$BASENAME" ] && return 0
+
+    # Download new one as alt-packagename.tar.ext
+    FILENAME="$ALTFILENAME"
+    SHA1=
+
+    ([ ! -z "$PREFERRED_MIRROR" ] &&
+      download_from "$PREFERRED_MIRROR/$ALTFILENAME") ||
+      download_from "$UNSTABLE"
+    return $?
+  fi
+
+  # If environment variable specifies a preferred mirror, try that first.
+
+  if [ ! -z "$PREFERRED_MIRROR" ]
+  then
+    download_from "$PREFERRED_MIRROR/$FILENAME" && return 0
+  fi
+
+  # Try original location, then mirrors.
+  # Note: the URLs in mirror list cannot contain whitespace.
+
+  download_from "$URL" && return 0
+  for i in $MIRROR_LIST
+  do
+    download_from "$i/$FILENAME" && return 0
+  done
+
+  # Return failure.
+
+  echo "Could not download $FILENAME"
+  echo -en "\e[0m"
+  return 1
+}
+
+# Clean obsolete files out of the source directory
+
+START_TIME=`date +%s`
+
+cleanup_oldfiles()
+{
+  # wait for asynchronous downloads to complete
+
+  wait
+
+  for i in "${SRCDIR}"/*
+  do
+    if [ -f "$i" ] && [ "$(date +%s -r "$i")" -lt "${START_TIME}" ]
+    then
+      echo Removing old file "$i"
+      rm -rf "$i"
+    fi
+  done
+}