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#define USE_THE_REPOSITORY_VARIABLE

#include "git-compat-util.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,

unsigned expected_alignment)

{

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;

}

if (chunk_offset % expected_alignment != 0) {

error(_("chunk id %"PRIx32" not %d-byte aligned"),

chunk_id, expected_alignment);

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;

}

struct pair_chunk_data {

const unsigned char **p;

size_t *size;

};

static int pair_chunk_fn(const unsigned char *chunk_start,

size_t chunk_size,

void *data)

{

struct pair_chunk_data *pcd = data;

*pcd->p = chunk_start;

*pcd->size = chunk_size;

return 0;

}

int pair_chunk(struct chunkfile *cf,

uint32_t chunk_id,

const unsigned char **p,

size_t *size)

{

struct pair_chunk_data pcd = { .p = p, .size = size };

return read_chunk(cf, chunk_id, pair_chunk_fn, &pcd);

}

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"));

}

}