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Commit | Line | Data |
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171bdaca JK |
1 | # Support routines for hand-crafting weird or malicious packs. |
2 | # | |
3 | # You can make a complete pack like: | |
4 | # | |
5 | # pack_header 2 >foo.pack && | |
6 | # pack_obj e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 >>foo.pack && | |
7 | # pack_obj e68fe8129b546b101aee9510c5328e7f21ca1d18 >>foo.pack && | |
8 | # pack_trailer foo.pack | |
9 | ||
10 | # Print the big-endian 4-byte octal representation of $1 | |
11 | uint32_octal () { | |
12 | n=$1 | |
fbc812a6 KK |
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 )); | |
171bdaca JK |
17 | } |
18 | ||
19 | # Print the big-endian 4-byte binary representation of $1 | |
20 | uint32_binary () { | |
21 | printf "$(uint32_octal "$1")" | |
22 | } | |
23 | ||
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" | |
29 | } | |
30 | ||
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 | |
45 | ;; | |
46 | esac | |
47 | ;; | |
48 | ||
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 | |
55 | ;; | |
3b910d0c JK |
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 | |
61 | ;; | |
62 | esac | |
63 | ;; | |
64 | ||
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 | |
71 | ;; | |
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 | |
77 | ;; | |
171bdaca JK |
78 | esac |
79 | ;; | |
80 | esac | |
81 | ||
82 | echo >&2 "BUG: don't know how to print $1${2:+ (from $2)}" | |
83 | return 1 | |
84 | } | |
85 | ||
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 | |
91 | } | |
92 | ||
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/* | |
98 | } |