| #include "git-compat-util.h" |
| #include "alloc.h" |
| #include "chunk-format.h" |
| #include "csum-file.h" |
| #include "gettext.h" |
| #include "hash.h" |
| #include "trace2.h" |
| |
| /* |
| * When writing a chunk-based file format, collect the chunks in |
| * an array of chunk_info structs. The size stores the _expected_ |
| * amount of data that will be written by write_fn. |
| */ |
| struct chunk_info { |
| uint32_t id; |
| uint64_t size; |
| chunk_write_fn write_fn; |
| |
| const void *start; |
| }; |
| |
| struct chunkfile { |
| struct hashfile *f; |
| |
| struct chunk_info *chunks; |
| size_t chunks_nr; |
| size_t chunks_alloc; |
| }; |
| |
| struct chunkfile *init_chunkfile(struct hashfile *f) |
| { |
| struct chunkfile *cf = xcalloc(1, sizeof(*cf)); |
| cf->f = f; |
| return cf; |
| } |
| |
| void free_chunkfile(struct chunkfile *cf) |
| { |
| if (!cf) |
| return; |
| free(cf->chunks); |
| free(cf); |
| } |
| |
| int get_num_chunks(struct chunkfile *cf) |
| { |
| return cf->chunks_nr; |
| } |
| |
| void add_chunk(struct chunkfile *cf, |
| uint32_t id, |
| size_t size, |
| chunk_write_fn fn) |
| { |
| ALLOC_GROW(cf->chunks, cf->chunks_nr + 1, cf->chunks_alloc); |
| |
| cf->chunks[cf->chunks_nr].id = id; |
| cf->chunks[cf->chunks_nr].write_fn = fn; |
| cf->chunks[cf->chunks_nr].size = size; |
| cf->chunks_nr++; |
| } |
| |
| int write_chunkfile(struct chunkfile *cf, void *data) |
| { |
| int i, result = 0; |
| uint64_t cur_offset = hashfile_total(cf->f); |
| |
| trace2_region_enter("chunkfile", "write", the_repository); |
| |
| /* Add the table of contents to the current offset */ |
| cur_offset += (cf->chunks_nr + 1) * CHUNK_TOC_ENTRY_SIZE; |
| |
| for (i = 0; i < cf->chunks_nr; i++) { |
| hashwrite_be32(cf->f, cf->chunks[i].id); |
| hashwrite_be64(cf->f, cur_offset); |
| |
| cur_offset += cf->chunks[i].size; |
| } |
| |
| /* Trailing entry marks the end of the chunks */ |
| hashwrite_be32(cf->f, 0); |
| hashwrite_be64(cf->f, cur_offset); |
| |
| for (i = 0; i < cf->chunks_nr; i++) { |
| off_t start_offset = hashfile_total(cf->f); |
| result = cf->chunks[i].write_fn(cf->f, data); |
| |
| if (result) |
| goto cleanup; |
| |
| if (hashfile_total(cf->f) - start_offset != cf->chunks[i].size) |
| BUG("expected to write %"PRId64" bytes to chunk %"PRIx32", but wrote %"PRId64" instead", |
| cf->chunks[i].size, cf->chunks[i].id, |
| hashfile_total(cf->f) - start_offset); |
| } |
| |
| cleanup: |
| trace2_region_leave("chunkfile", "write", the_repository); |
| return result; |
| } |
| |
| int read_table_of_contents(struct chunkfile *cf, |
| const unsigned char *mfile, |
| size_t mfile_size, |
| uint64_t toc_offset, |
| int toc_length) |
| { |
| int i; |
| uint32_t chunk_id; |
| const unsigned char *table_of_contents = mfile + toc_offset; |
| |
| ALLOC_GROW(cf->chunks, toc_length, cf->chunks_alloc); |
| |
| while (toc_length--) { |
| uint64_t chunk_offset, next_chunk_offset; |
| |
| chunk_id = get_be32(table_of_contents); |
| chunk_offset = get_be64(table_of_contents + 4); |
| |
| if (!chunk_id) { |
| error(_("terminating chunk id appears earlier than expected")); |
| return 1; |
| } |
| |
| table_of_contents += CHUNK_TOC_ENTRY_SIZE; |
| next_chunk_offset = get_be64(table_of_contents + 4); |
| |
| if (next_chunk_offset < chunk_offset || |
| next_chunk_offset > mfile_size - the_hash_algo->rawsz) { |
| error(_("improper chunk offset(s) %"PRIx64" and %"PRIx64""), |
| chunk_offset, next_chunk_offset); |
| return -1; |
| } |
| |
| for (i = 0; i < cf->chunks_nr; i++) { |
| if (cf->chunks[i].id == chunk_id) { |
| error(_("duplicate chunk ID %"PRIx32" found"), |
| chunk_id); |
| return -1; |
| } |
| } |
| |
| cf->chunks[cf->chunks_nr].id = chunk_id; |
| cf->chunks[cf->chunks_nr].start = mfile + chunk_offset; |
| cf->chunks[cf->chunks_nr].size = next_chunk_offset - chunk_offset; |
| cf->chunks_nr++; |
| } |
| |
| chunk_id = get_be32(table_of_contents); |
| if (chunk_id) { |
| error(_("final chunk has non-zero id %"PRIx32""), chunk_id); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static int pair_chunk_fn(const unsigned char *chunk_start, |
| size_t chunk_size, |
| void *data) |
| { |
| const unsigned char **p = data; |
| *p = chunk_start; |
| return 0; |
| } |
| |
| int pair_chunk(struct chunkfile *cf, |
| uint32_t chunk_id, |
| const unsigned char **p) |
| { |
| return read_chunk(cf, chunk_id, pair_chunk_fn, p); |
| } |
| |
| int read_chunk(struct chunkfile *cf, |
| uint32_t chunk_id, |
| chunk_read_fn fn, |
| void *data) |
| { |
| int i; |
| |
| for (i = 0; i < cf->chunks_nr; i++) { |
| if (cf->chunks[i].id == chunk_id) |
| return fn(cf->chunks[i].start, cf->chunks[i].size, data); |
| } |
| |
| return CHUNK_NOT_FOUND; |
| } |
| |
| uint8_t oid_version(const struct git_hash_algo *algop) |
| { |
| switch (hash_algo_by_ptr(algop)) { |
| case GIT_HASH_SHA1: |
| return 1; |
| case GIT_HASH_SHA256: |
| return 2; |
| default: |
| die(_("invalid hash version")); |
| } |
| } |