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36bf1958 EN |
1 | #include "git-compat-util.h" |
2 | #include "alloc.h" | |
570df426 DS |
3 | #include "chunk-format.h" |
4 | #include "csum-file.h" | |
f394e093 | 5 | #include "gettext.h" |
570df426 DS |
6 | |
7 | /* | |
8 | * When writing a chunk-based file format, collect the chunks in | |
9 | * an array of chunk_info structs. The size stores the _expected_ | |
10 | * amount of data that will be written by write_fn. | |
11 | */ | |
12 | struct chunk_info { | |
13 | uint32_t id; | |
14 | uint64_t size; | |
15 | chunk_write_fn write_fn; | |
5f0879f5 DS |
16 | |
17 | const void *start; | |
570df426 DS |
18 | }; |
19 | ||
20 | struct chunkfile { | |
21 | struct hashfile *f; | |
22 | ||
23 | struct chunk_info *chunks; | |
24 | size_t chunks_nr; | |
25 | size_t chunks_alloc; | |
26 | }; | |
27 | ||
28 | struct chunkfile *init_chunkfile(struct hashfile *f) | |
29 | { | |
30 | struct chunkfile *cf = xcalloc(1, sizeof(*cf)); | |
31 | cf->f = f; | |
32 | return cf; | |
33 | } | |
34 | ||
35 | void free_chunkfile(struct chunkfile *cf) | |
36 | { | |
37 | if (!cf) | |
38 | return; | |
39 | free(cf->chunks); | |
40 | free(cf); | |
41 | } | |
42 | ||
43 | int get_num_chunks(struct chunkfile *cf) | |
44 | { | |
45 | return cf->chunks_nr; | |
46 | } | |
47 | ||
48 | void add_chunk(struct chunkfile *cf, | |
49 | uint32_t id, | |
50 | size_t size, | |
51 | chunk_write_fn fn) | |
52 | { | |
53 | ALLOC_GROW(cf->chunks, cf->chunks_nr + 1, cf->chunks_alloc); | |
54 | ||
55 | cf->chunks[cf->chunks_nr].id = id; | |
56 | cf->chunks[cf->chunks_nr].write_fn = fn; | |
57 | cf->chunks[cf->chunks_nr].size = size; | |
58 | cf->chunks_nr++; | |
59 | } | |
60 | ||
61 | int write_chunkfile(struct chunkfile *cf, void *data) | |
62 | { | |
2ca245f8 | 63 | int i, result = 0; |
570df426 DS |
64 | uint64_t cur_offset = hashfile_total(cf->f); |
65 | ||
2ca245f8 DS |
66 | trace2_region_enter("chunkfile", "write", the_repository); |
67 | ||
570df426 DS |
68 | /* Add the table of contents to the current offset */ |
69 | cur_offset += (cf->chunks_nr + 1) * CHUNK_TOC_ENTRY_SIZE; | |
70 | ||
71 | for (i = 0; i < cf->chunks_nr; i++) { | |
72 | hashwrite_be32(cf->f, cf->chunks[i].id); | |
73 | hashwrite_be64(cf->f, cur_offset); | |
74 | ||
75 | cur_offset += cf->chunks[i].size; | |
76 | } | |
77 | ||
78 | /* Trailing entry marks the end of the chunks */ | |
79 | hashwrite_be32(cf->f, 0); | |
80 | hashwrite_be64(cf->f, cur_offset); | |
81 | ||
82 | for (i = 0; i < cf->chunks_nr; i++) { | |
83 | off_t start_offset = hashfile_total(cf->f); | |
2ca245f8 | 84 | result = cf->chunks[i].write_fn(cf->f, data); |
570df426 DS |
85 | |
86 | if (result) | |
2ca245f8 | 87 | goto cleanup; |
570df426 DS |
88 | |
89 | if (hashfile_total(cf->f) - start_offset != cf->chunks[i].size) | |
90 | BUG("expected to write %"PRId64" bytes to chunk %"PRIx32", but wrote %"PRId64" instead", | |
91 | cf->chunks[i].size, cf->chunks[i].id, | |
92 | hashfile_total(cf->f) - start_offset); | |
93 | } | |
94 | ||
2ca245f8 DS |
95 | cleanup: |
96 | trace2_region_leave("chunkfile", "write", the_repository); | |
97 | return result; | |
570df426 | 98 | } |
5f0879f5 DS |
99 | |
100 | int read_table_of_contents(struct chunkfile *cf, | |
101 | const unsigned char *mfile, | |
102 | size_t mfile_size, | |
103 | uint64_t toc_offset, | |
104 | int toc_length) | |
105 | { | |
5387fefa | 106 | int i; |
5f0879f5 DS |
107 | uint32_t chunk_id; |
108 | const unsigned char *table_of_contents = mfile + toc_offset; | |
109 | ||
110 | ALLOC_GROW(cf->chunks, toc_length, cf->chunks_alloc); | |
111 | ||
112 | while (toc_length--) { | |
113 | uint64_t chunk_offset, next_chunk_offset; | |
114 | ||
115 | chunk_id = get_be32(table_of_contents); | |
116 | chunk_offset = get_be64(table_of_contents + 4); | |
117 | ||
118 | if (!chunk_id) { | |
119 | error(_("terminating chunk id appears earlier than expected")); | |
120 | return 1; | |
121 | } | |
122 | ||
123 | table_of_contents += CHUNK_TOC_ENTRY_SIZE; | |
124 | next_chunk_offset = get_be64(table_of_contents + 4); | |
125 | ||
126 | if (next_chunk_offset < chunk_offset || | |
127 | next_chunk_offset > mfile_size - the_hash_algo->rawsz) { | |
128 | error(_("improper chunk offset(s) %"PRIx64" and %"PRIx64""), | |
129 | chunk_offset, next_chunk_offset); | |
130 | return -1; | |
131 | } | |
132 | ||
5387fefa DS |
133 | for (i = 0; i < cf->chunks_nr; i++) { |
134 | if (cf->chunks[i].id == chunk_id) { | |
135 | error(_("duplicate chunk ID %"PRIx32" found"), | |
136 | chunk_id); | |
137 | return -1; | |
138 | } | |
139 | } | |
140 | ||
5f0879f5 DS |
141 | cf->chunks[cf->chunks_nr].id = chunk_id; |
142 | cf->chunks[cf->chunks_nr].start = mfile + chunk_offset; | |
143 | cf->chunks[cf->chunks_nr].size = next_chunk_offset - chunk_offset; | |
144 | cf->chunks_nr++; | |
145 | } | |
146 | ||
147 | chunk_id = get_be32(table_of_contents); | |
148 | if (chunk_id) { | |
149 | error(_("final chunk has non-zero id %"PRIx32""), chunk_id); | |
150 | return -1; | |
151 | } | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
156 | static int pair_chunk_fn(const unsigned char *chunk_start, | |
157 | size_t chunk_size, | |
158 | void *data) | |
159 | { | |
160 | const unsigned char **p = data; | |
161 | *p = chunk_start; | |
162 | return 0; | |
163 | } | |
164 | ||
165 | int pair_chunk(struct chunkfile *cf, | |
166 | uint32_t chunk_id, | |
167 | const unsigned char **p) | |
168 | { | |
169 | return read_chunk(cf, chunk_id, pair_chunk_fn, p); | |
170 | } | |
171 | ||
172 | int read_chunk(struct chunkfile *cf, | |
173 | uint32_t chunk_id, | |
174 | chunk_read_fn fn, | |
175 | void *data) | |
176 | { | |
177 | int i; | |
178 | ||
179 | for (i = 0; i < cf->chunks_nr; i++) { | |
180 | if (cf->chunks[i].id == chunk_id) | |
181 | return fn(cf->chunks[i].start, cf->chunks[i].size, data); | |
182 | } | |
183 | ||
184 | return CHUNK_NOT_FOUND; | |
185 | } | |
d9fef9d9 TB |
186 | |
187 | uint8_t oid_version(const struct git_hash_algo *algop) | |
188 | { | |
189 | switch (hash_algo_by_ptr(algop)) { | |
190 | case GIT_HASH_SHA1: | |
191 | return 1; | |
192 | case GIT_HASH_SHA256: | |
193 | return 2; | |
194 | default: | |
195 | die(_("invalid hash version")); | |
196 | } | |
197 | } |