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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" |
d1cbe1e6 | 6 | #include "hash.h" |
ec2f0269 | 7 | #include "trace2.h" |
570df426 DS |
8 | |
9 | /* | |
10 | * When writing a chunk-based file format, collect the chunks in | |
11 | * an array of chunk_info structs. The size stores the _expected_ | |
12 | * amount of data that will be written by write_fn. | |
13 | */ | |
14 | struct chunk_info { | |
15 | uint32_t id; | |
16 | uint64_t size; | |
17 | chunk_write_fn write_fn; | |
5f0879f5 DS |
18 | |
19 | const void *start; | |
570df426 DS |
20 | }; |
21 | ||
22 | struct chunkfile { | |
23 | struct hashfile *f; | |
24 | ||
25 | struct chunk_info *chunks; | |
26 | size_t chunks_nr; | |
27 | size_t chunks_alloc; | |
28 | }; | |
29 | ||
30 | struct chunkfile *init_chunkfile(struct hashfile *f) | |
31 | { | |
32 | struct chunkfile *cf = xcalloc(1, sizeof(*cf)); | |
33 | cf->f = f; | |
34 | return cf; | |
35 | } | |
36 | ||
37 | void free_chunkfile(struct chunkfile *cf) | |
38 | { | |
39 | if (!cf) | |
40 | return; | |
41 | free(cf->chunks); | |
42 | free(cf); | |
43 | } | |
44 | ||
45 | int get_num_chunks(struct chunkfile *cf) | |
46 | { | |
47 | return cf->chunks_nr; | |
48 | } | |
49 | ||
50 | void add_chunk(struct chunkfile *cf, | |
51 | uint32_t id, | |
52 | size_t size, | |
53 | chunk_write_fn fn) | |
54 | { | |
55 | ALLOC_GROW(cf->chunks, cf->chunks_nr + 1, cf->chunks_alloc); | |
56 | ||
57 | cf->chunks[cf->chunks_nr].id = id; | |
58 | cf->chunks[cf->chunks_nr].write_fn = fn; | |
59 | cf->chunks[cf->chunks_nr].size = size; | |
60 | cf->chunks_nr++; | |
61 | } | |
62 | ||
63 | int write_chunkfile(struct chunkfile *cf, void *data) | |
64 | { | |
2ca245f8 | 65 | int i, result = 0; |
570df426 DS |
66 | uint64_t cur_offset = hashfile_total(cf->f); |
67 | ||
2ca245f8 DS |
68 | trace2_region_enter("chunkfile", "write", the_repository); |
69 | ||
570df426 DS |
70 | /* Add the table of contents to the current offset */ |
71 | cur_offset += (cf->chunks_nr + 1) * CHUNK_TOC_ENTRY_SIZE; | |
72 | ||
73 | for (i = 0; i < cf->chunks_nr; i++) { | |
74 | hashwrite_be32(cf->f, cf->chunks[i].id); | |
75 | hashwrite_be64(cf->f, cur_offset); | |
76 | ||
77 | cur_offset += cf->chunks[i].size; | |
78 | } | |
79 | ||
80 | /* Trailing entry marks the end of the chunks */ | |
81 | hashwrite_be32(cf->f, 0); | |
82 | hashwrite_be64(cf->f, cur_offset); | |
83 | ||
84 | for (i = 0; i < cf->chunks_nr; i++) { | |
85 | off_t start_offset = hashfile_total(cf->f); | |
2ca245f8 | 86 | result = cf->chunks[i].write_fn(cf->f, data); |
570df426 DS |
87 | |
88 | if (result) | |
2ca245f8 | 89 | goto cleanup; |
570df426 DS |
90 | |
91 | if (hashfile_total(cf->f) - start_offset != cf->chunks[i].size) | |
92 | BUG("expected to write %"PRId64" bytes to chunk %"PRIx32", but wrote %"PRId64" instead", | |
93 | cf->chunks[i].size, cf->chunks[i].id, | |
94 | hashfile_total(cf->f) - start_offset); | |
95 | } | |
96 | ||
2ca245f8 DS |
97 | cleanup: |
98 | trace2_region_leave("chunkfile", "write", the_repository); | |
99 | return result; | |
570df426 | 100 | } |
5f0879f5 DS |
101 | |
102 | int read_table_of_contents(struct chunkfile *cf, | |
103 | const unsigned char *mfile, | |
104 | size_t mfile_size, | |
105 | uint64_t toc_offset, | |
106 | int toc_length) | |
107 | { | |
5387fefa | 108 | int i; |
5f0879f5 DS |
109 | uint32_t chunk_id; |
110 | const unsigned char *table_of_contents = mfile + toc_offset; | |
111 | ||
112 | ALLOC_GROW(cf->chunks, toc_length, cf->chunks_alloc); | |
113 | ||
114 | while (toc_length--) { | |
115 | uint64_t chunk_offset, next_chunk_offset; | |
116 | ||
117 | chunk_id = get_be32(table_of_contents); | |
118 | chunk_offset = get_be64(table_of_contents + 4); | |
119 | ||
120 | if (!chunk_id) { | |
121 | error(_("terminating chunk id appears earlier than expected")); | |
122 | return 1; | |
123 | } | |
124 | ||
125 | table_of_contents += CHUNK_TOC_ENTRY_SIZE; | |
126 | next_chunk_offset = get_be64(table_of_contents + 4); | |
127 | ||
128 | if (next_chunk_offset < chunk_offset || | |
129 | next_chunk_offset > mfile_size - the_hash_algo->rawsz) { | |
130 | error(_("improper chunk offset(s) %"PRIx64" and %"PRIx64""), | |
131 | chunk_offset, next_chunk_offset); | |
132 | return -1; | |
133 | } | |
134 | ||
5387fefa DS |
135 | for (i = 0; i < cf->chunks_nr; i++) { |
136 | if (cf->chunks[i].id == chunk_id) { | |
137 | error(_("duplicate chunk ID %"PRIx32" found"), | |
138 | chunk_id); | |
139 | return -1; | |
140 | } | |
141 | } | |
142 | ||
5f0879f5 DS |
143 | cf->chunks[cf->chunks_nr].id = chunk_id; |
144 | cf->chunks[cf->chunks_nr].start = mfile + chunk_offset; | |
145 | cf->chunks[cf->chunks_nr].size = next_chunk_offset - chunk_offset; | |
146 | cf->chunks_nr++; | |
147 | } | |
148 | ||
149 | chunk_id = get_be32(table_of_contents); | |
150 | if (chunk_id) { | |
151 | error(_("final chunk has non-zero id %"PRIx32""), chunk_id); | |
152 | return -1; | |
153 | } | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | static int pair_chunk_fn(const unsigned char *chunk_start, | |
159 | size_t chunk_size, | |
160 | void *data) | |
161 | { | |
162 | const unsigned char **p = data; | |
163 | *p = chunk_start; | |
164 | return 0; | |
165 | } | |
166 | ||
167 | int pair_chunk(struct chunkfile *cf, | |
168 | uint32_t chunk_id, | |
169 | const unsigned char **p) | |
170 | { | |
171 | return read_chunk(cf, chunk_id, pair_chunk_fn, p); | |
172 | } | |
173 | ||
174 | int read_chunk(struct chunkfile *cf, | |
175 | uint32_t chunk_id, | |
176 | chunk_read_fn fn, | |
177 | void *data) | |
178 | { | |
179 | int i; | |
180 | ||
181 | for (i = 0; i < cf->chunks_nr; i++) { | |
182 | if (cf->chunks[i].id == chunk_id) | |
183 | return fn(cf->chunks[i].start, cf->chunks[i].size, data); | |
184 | } | |
185 | ||
186 | return CHUNK_NOT_FOUND; | |
187 | } | |
d9fef9d9 TB |
188 | |
189 | uint8_t oid_version(const struct git_hash_algo *algop) | |
190 | { | |
191 | switch (hash_algo_by_ptr(algop)) { | |
192 | case GIT_HASH_SHA1: | |
193 | return 1; | |
194 | case GIT_HASH_SHA256: | |
195 | return 2; | |
196 | default: | |
197 | die(_("invalid hash version")); | |
198 | } | |
199 | } |