1 #include "git-compat-util.h"
3 #include "chunk-format.h"
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.
15 chunk_write_fn write_fn
;
23 struct chunk_info
*chunks
;
28 struct chunkfile
*init_chunkfile(struct hashfile
*f
)
30 struct chunkfile
*cf
= xcalloc(1, sizeof(*cf
));
35 void free_chunkfile(struct chunkfile
*cf
)
43 int get_num_chunks(struct chunkfile
*cf
)
48 void add_chunk(struct chunkfile
*cf
,
53 ALLOC_GROW(cf
->chunks
, cf
->chunks_nr
+ 1, cf
->chunks_alloc
);
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
;
61 int write_chunkfile(struct chunkfile
*cf
, void *data
)
64 uint64_t cur_offset
= hashfile_total(cf
->f
);
66 trace2_region_enter("chunkfile", "write", the_repository
);
68 /* Add the table of contents to the current offset */
69 cur_offset
+= (cf
->chunks_nr
+ 1) * CHUNK_TOC_ENTRY_SIZE
;
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
);
75 cur_offset
+= cf
->chunks
[i
].size
;
78 /* Trailing entry marks the end of the chunks */
79 hashwrite_be32(cf
->f
, 0);
80 hashwrite_be64(cf
->f
, cur_offset
);
82 for (i
= 0; i
< cf
->chunks_nr
; i
++) {
83 off_t start_offset
= hashfile_total(cf
->f
);
84 result
= cf
->chunks
[i
].write_fn(cf
->f
, data
);
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
);
96 trace2_region_leave("chunkfile", "write", the_repository
);
100 int read_table_of_contents(struct chunkfile
*cf
,
101 const unsigned char *mfile
,
108 const unsigned char *table_of_contents
= mfile
+ toc_offset
;
110 ALLOC_GROW(cf
->chunks
, toc_length
, cf
->chunks_alloc
);
112 while (toc_length
--) {
113 uint64_t chunk_offset
, next_chunk_offset
;
115 chunk_id
= get_be32(table_of_contents
);
116 chunk_offset
= get_be64(table_of_contents
+ 4);
119 error(_("terminating chunk id appears earlier than expected"));
123 table_of_contents
+= CHUNK_TOC_ENTRY_SIZE
;
124 next_chunk_offset
= get_be64(table_of_contents
+ 4);
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
);
133 for (i
= 0; i
< cf
->chunks_nr
; i
++) {
134 if (cf
->chunks
[i
].id
== chunk_id
) {
135 error(_("duplicate chunk ID %"PRIx32
" found"),
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
;
147 chunk_id
= get_be32(table_of_contents
);
149 error(_("final chunk has non-zero id %"PRIx32
""), chunk_id
);
156 static int pair_chunk_fn(const unsigned char *chunk_start
,
160 const unsigned char **p
= data
;
165 int pair_chunk(struct chunkfile
*cf
,
167 const unsigned char **p
)
169 return read_chunk(cf
, chunk_id
, pair_chunk_fn
, p
);
172 int read_chunk(struct chunkfile
*cf
,
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
);
184 return CHUNK_NOT_FOUND
;
187 uint8_t oid_version(const struct git_hash_algo
*algop
)
189 switch (hash_algo_by_ptr(algop
)) {
192 case GIT_HASH_SHA256
:
195 die(_("invalid hash version"));