doc: describe git svn init --ignore-refs
[git/git-svn.git] / t / lib-pack.sh
blob75098465716512a3373e64d51a5cdf848e9f1101
1 # Support routines for hand-crafting weird or malicious packs.
3 # You can make a complete pack like:
5 # pack_header 2 >foo.pack &&
6 # pack_obj e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 >>foo.pack &&
7 # pack_obj e68fe8129b546b101aee9510c5328e7f21ca1d18 >>foo.pack &&
8 # pack_trailer foo.pack
10 # Print the big-endian 4-byte octal representation of $1
11 uint32_octal () {
12 n=$1
13 printf '\\%o' $(($n / 16777216)); n=$((n % 16777216))
14 printf '\\%o' $(($n / 65536)); n=$((n % 65536))
15 printf '\\%o' $(($n / 256)); n=$((n % 256))
16 printf '\\%o' $(($n ));
19 # Print the big-endian 4-byte binary representation of $1
20 uint32_binary () {
21 printf "$(uint32_octal "$1")"
24 # Print a pack header, version 2, for a pack with $1 objects
25 pack_header () {
26 printf 'PACK' &&
27 printf '\0\0\0\2' &&
28 uint32_binary "$1"
31 # Print the pack data for object $1, as a delta against object $2 (or as a full
32 # object if $2 is missing or empty). The output is suitable for including
33 # directly in the packfile, and represents the entirety of the object entry.
34 # Doing this on the fly (especially picking your deltas) is quite tricky, so we
35 # have hardcoded some well-known objects. See the case statements below for the
36 # complete list.
37 pack_obj () {
38 case "$1" in
39 # empty blob
40 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391)
41 case "$2" in
42 '')
43 printf '\060\170\234\003\0\0\0\0\1'
44 return
46 esac
49 # blob containing "\7\76"
50 e68fe8129b546b101aee9510c5328e7f21ca1d18)
51 case "$2" in
52 '')
53 printf '\062\170\234\143\267\3\0\0\116\0\106'
54 return
56 01d7713666f4de822776c7622c10f1b07de280dc)
57 printf '\165\1\327\161\66\146\364\336\202\47\166' &&
58 printf '\307\142\54\20\361\260\175\342\200\334\170' &&
59 printf '\234\143\142\142\142\267\003\0\0\151\0\114'
60 return
62 esac
65 # blob containing "\7\0"
66 01d7713666f4de822776c7622c10f1b07de280dc)
67 case "$2" in
68 '')
69 printf '\062\170\234\143\147\0\0\0\20\0\10'
70 return
72 e68fe8129b546b101aee9510c5328e7f21ca1d18)
73 printf '\165\346\217\350\22\233\124\153\20\32\356' &&
74 printf '\225\20\305\62\216\177\41\312\35\30\170\234' &&
75 printf '\143\142\142\142\147\0\0\0\53\0\16'
76 return
78 esac
80 esac
82 echo >&2 "BUG: don't know how to print $1${2:+ (from $2)}"
83 return 1
86 # Compute and append pack trailer to "$1"
87 pack_trailer () {
88 test-sha1 -b <"$1" >trailer.tmp &&
89 cat trailer.tmp >>"$1" &&
90 rm -f trailer.tmp
93 # Remove any existing packs to make sure that
94 # whatever we index next will be the pack that we
95 # actually use.
96 clear_packs () {
97 rm -f .git/objects/pack/*