pack-objects: use rev.filter when possible
[git/debian.git] / chunk-format.h
blob9ccbe0037792c36620644996de66f5f779f93e98
1 #ifndef CHUNK_FORMAT_H
2 #define CHUNK_FORMAT_H
4 #include "git-compat-util.h"
6 struct hashfile;
7 struct chunkfile;
9 #define CHUNK_TOC_ENTRY_SIZE (sizeof(uint32_t) + sizeof(uint64_t))
12 * Initialize a 'struct chunkfile' for writing _or_ reading a file
13 * with the chunk format.
15 * If writing a file, supply a non-NULL 'struct hashfile *' that will
16 * be used to write.
18 * If reading a file, use a NULL 'struct hashfile *' and then call
19 * read_table_of_contents(). Supply the memory-mapped data to the
20 * pair_chunk() or read_chunk() methods, as appropriate.
22 * DO NOT MIX THESE MODES. Use different 'struct chunkfile' instances
23 * for reading and writing.
25 struct chunkfile *init_chunkfile(struct hashfile *f);
26 void free_chunkfile(struct chunkfile *cf);
27 int get_num_chunks(struct chunkfile *cf);
28 typedef int (*chunk_write_fn)(struct hashfile *f, void *data);
29 void add_chunk(struct chunkfile *cf,
30 uint32_t id,
31 size_t size,
32 chunk_write_fn fn);
33 int write_chunkfile(struct chunkfile *cf, void *data);
35 int read_table_of_contents(struct chunkfile *cf,
36 const unsigned char *mfile,
37 size_t mfile_size,
38 uint64_t toc_offset,
39 int toc_length);
41 #define CHUNK_NOT_FOUND (-2)
44 * Find 'chunk_id' in the given chunkfile and assign the
45 * given pointer to the position in the mmap'd file where
46 * that chunk begins.
48 * Returns CHUNK_NOT_FOUND if the chunk does not exist.
50 int pair_chunk(struct chunkfile *cf,
51 uint32_t chunk_id,
52 const unsigned char **p);
54 typedef int (*chunk_read_fn)(const unsigned char *chunk_start,
55 size_t chunk_size, void *data);
57 * Find 'chunk_id' in the given chunkfile and call the
58 * given chunk_read_fn method with the information for
59 * that chunk.
61 * Returns CHUNK_NOT_FOUND if the chunk does not exist.
63 int read_chunk(struct chunkfile *cf,
64 uint32_t chunk_id,
65 chunk_read_fn fn,
66 void *data);
68 #endif