diff options
Diffstat (limited to 'chunk-format.h')
-rw-r--r-- | chunk-format.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/chunk-format.h b/chunk-format.h index ce598b66d9..9ccbe00377 100644 --- a/chunk-format.h +++ b/chunk-format.h @@ -8,6 +8,20 @@ struct chunkfile; #define CHUNK_TOC_ENTRY_SIZE (sizeof(uint32_t) + sizeof(uint64_t)) +/* + * Initialize a 'struct chunkfile' for writing _or_ reading a file + * with the chunk format. + * + * If writing a file, supply a non-NULL 'struct hashfile *' that will + * be used to write. + * + * If reading a file, use a NULL 'struct hashfile *' and then call + * read_table_of_contents(). Supply the memory-mapped data to the + * pair_chunk() or read_chunk() methods, as appropriate. + * + * DO NOT MIX THESE MODES. Use different 'struct chunkfile' instances + * for reading and writing. + */ struct chunkfile *init_chunkfile(struct hashfile *f); void free_chunkfile(struct chunkfile *cf); int get_num_chunks(struct chunkfile *cf); @@ -18,4 +32,37 @@ void add_chunk(struct chunkfile *cf, chunk_write_fn fn); int write_chunkfile(struct chunkfile *cf, void *data); +int read_table_of_contents(struct chunkfile *cf, + const unsigned char *mfile, + size_t mfile_size, + uint64_t toc_offset, + int toc_length); + +#define CHUNK_NOT_FOUND (-2) + +/* + * Find 'chunk_id' in the given chunkfile and assign the + * given pointer to the position in the mmap'd file where + * that chunk begins. + * + * Returns CHUNK_NOT_FOUND if the chunk does not exist. + */ +int pair_chunk(struct chunkfile *cf, + uint32_t chunk_id, + const unsigned char **p); + +typedef int (*chunk_read_fn)(const unsigned char *chunk_start, + size_t chunk_size, void *data); +/* + * Find 'chunk_id' in the given chunkfile and call the + * given chunk_read_fn method with the information for + * that chunk. + * + * Returns CHUNK_NOT_FOUND if the chunk does not exist. + */ +int read_chunk(struct chunkfile *cf, + uint32_t chunk_id, + chunk_read_fn fn, + void *data); + #endif |