git/chunk-format.c, branch v2.32.2

chunk-format: restore duplicate chunk checks

2021-02-18T21:38:16Z

Before refactoring into the chunk-format API, the commit-graph parsing logic included checks for duplicate chunks. It is unlikely that we would desire a chunk-based file format that allows duplicate chunk IDs in the table of contents, so add duplicate checks into read_table_of_contents(). Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

chunk-format: create read chunk API

2021-02-18T21:38:16Z

Add the capability to read the table of contents, then pair the chunks with necessary logic using read_chunk_fn pointers. Callers will be added in future changes, but the typical outline will be: 1. initialize a 'struct chunkfile' with init_chunkfile(NULL). 2. call read_table_of_contents(). 3. for each chunk to parse, a. call pair_chunk() to assign a pointer with the chunk position, or b. call read_chunk() to run a callback on the chunk start and size. 4. call free_chunkfile() to clear the 'struct chunkfile' data. We are re-using the anonymous 'struct chunkfile' data, as it is internal to the chunk-format API. This gives it essentially two modes: write and read. If the same struct instance was used for both reads and writes, then there would be failures. Helped-by: Junio C Hamano Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

chunk-format: create chunk format write API

2021-02-18T21:38:16Z

In anticipation of combining the logic from the commit-graph and multi-pack-index file formats, create a new chunk-format API. Use a 'struct chunkfile' pointer to keep track of data that has been registered for writes. This struct is anonymous outside of chunk-format.c to ensure no user attempts to interfere with the data. The next change will use this API in commit-graph.c, but the general approach is: 1. initialize the chunkfile with init_chunkfile(f). 2. add chunks in the intended writing order with add_chunk(). 3. write any header information to the hashfile f. 4. write the chunkfile data using write_chunkfile(). 5. free the chunkfile struct using free_chunkfile(). Helped-by: Taylor Blau Helped-by: Junio C Hamano Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano