[PATCH v2 00/17] Refactor chunk-format into an API
- From
Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Jan 27, 2021, 15:01 UTC
- Message-ID
- <pull.848.v2.git.1611759716.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.848.git.1611676886.gitgitgadget@gmail.com>
This is a restart on the topic previously submitted [1] but dropped because ak/corrected-commit-date was still in progress. This version is based on that branch.
[1] https://lore.kernel.org/git/pull.804.git.1607012215.gitgitgadget@gmail.com/
This version also changes the approach to use a more dynamic interaction with a struct chunkfile pointer. This idea is credited to Taylor Blau [2], but I started again from scratch. I also go further to make struct chunkfile anonymous to API consumers. It is defined only in chunk-format.c, which should hopefully deter future users from interacting with that data directly.
[2] https://lore.kernel.org/git/X8%2FI%2FRzXZksio+ri@nand.local/
This combined API is beneficial to reduce duplicated logic. Or rather, to ensure that similar file formats have similar protections against bad data. The multi-pack-index code did not have as many guards as the commit-graph code did, but now they both share a common base that checks for things like duplicate chunks or offsets outside the size of the file.
Here are some stats for the end-to-end change:
* 570 insertions(+), 456 deletions(-). * commit-graph.c: 107 insertions(+), 192 deletions(-) * midx.c: 164 insertions(+), 260 deletions(-)
While there is an overall increase to the code size, the consumers do get smaller. Boilerplate things like abstracting method to match chunk_write_fn and chunk_read_fn make up a lot of these insertions. The "interesting" code gets a lot smaller and cleaner.
Updates in V2 =============
* The method pair_chunk() now automatically sets a pointer while read_chunk() uses the callback. This greatly reduces the code size.
* Pointer casts are now implicit instead of explicit.
* Extra care is taken to not overflow when verifying chunk sizes on write.
Thanks, -Stolee
Derrick Stolee (17): commit-graph: anonymize data in chunk_write_fn chunk-format: create chunk format write API commit-graph: use chunk-format write API midx: rename pack_info to write_midx_context midx: use context in write_midx_pack_names() midx: add entries to write_midx_context midx: add pack_perm to write_midx_context midx: add num_large_offsets to write_midx_context midx: return success/failure in chunk write methods midx: drop chunk progress during write midx: use chunk-format API in write_midx_internal() chunk-format: create read chunk API commit-graph: use chunk-format read API midx: use chunk-format read API midx: use 64-bit multiplication for chunk sizes chunk-format: restore duplicate chunk checks chunk-format: add technical docs
Documentation/technical/chunk-format.txt | 54 +++ .../technical/commit-graph-format.txt | 3 + Documentation/technical/pack-format.txt | 3 + Makefile | 1 + chunk-format.c | 181 ++++++++ chunk-format.h | 53 +++ commit-graph.c | 299 +++++------- midx.c | 424 +++++++----------- t/t5318-commit-graph.sh | 2 +- t/t5319-multi-pack-index.sh | 6 +- 10 files changed, 570 insertions(+), 456 deletions(-) create mode 100644 Documentation/technical/chunk-format.txt create mode 100644 chunk-format.c create mode 100644 chunk-format.h
base-commit: 5a3b130cad0d5c770f766e3af6d32b41766374c0 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-848%2Fderrickstolee%2Fchunk-format%2Frefactor-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-848/derrickstolee/chunk-format/refactor-v2 Pull-Request: https://github.com/gitgitgadget/git/pull/848
Range-diff vs v1:
1: 09b32829e4f ! 1: 243dcec9436 commit-graph: anonymize data in chunk_write_fn
@@ commit-graph.c: struct write_commit_graph_context {
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
int i, count = 0;
struct commit **list = ctx->commits.list;
@@ commit-graph.c: static int write_graph_chunk_fanout(struct hashfile *f,
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
struct commit **list = ctx->commits.list;
int count;
for (count = 0; count < ctx->commits.nr; count++, list++) {
@@ commit-graph.c: static const unsigned char *commit_to_sha1(size_t index, void *t
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
struct commit **list = ctx->commits.list;
struct commit **last = ctx->commits.list + ctx->commits.nr;
uint32_t num_extra_edges = 0;
@@ commit-graph.c: static int write_graph_chunk_data(struct hashfile *f,
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
int i, num_generation_data_overflows = 0;
for (i = 0; i < ctx->commits.nr; i++) {
@@ commit-graph.c: static int write_graph_chunk_generation_data(struct hashfile *f,
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
int i;
for (i = 0; i < ctx->commits.nr; i++) {
struct commit *c = ctx->commits.list[i];
@@ commit-graph.c: static int write_graph_chunk_generation_data_overflow(struct has
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
struct commit **list = ctx->commits.list;
struct commit **last = ctx->commits.list + ctx->commits.nr;
struct commit_list *parent;
@@ commit-graph.c: static int write_graph_chunk_extra_edges(struct hashfile *f,
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
struct commit **list = ctx->commits.list;
struct commit **last = ctx->commits.list + ctx->commits.nr;
uint32_t cur_pos = 0;
@@ commit-graph.c: static void trace2_bloom_filter_settings(struct write_commit_gra
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
struct commit **list = ctx->commits.list;
struct commit **last = ctx->commits.list + ctx->commits.nr;
@@ commit-graph.c: static int write_graph_chunk_base_1(struct hashfile *f,
- struct write_commit_graph_context *ctx)
+ void *data)
{
-+ struct write_commit_graph_context *ctx =
-+ (struct write_commit_graph_context *)data;
++ struct write_commit_graph_context *ctx = data;
int num = write_graph_chunk_base_1(f, ctx->new_base_graph);
if (num != ctx->num_commit_graphs_after - 1) {
2: 9bd273f8c94 ! 2: 814512f2167 chunk-format: create chunk format write API
@@ chunk-format.c (new)
+ if (result)
+ return result;
+
-+ if (cf->f->total + cf->f->offset != start_offset + cf->chunks[i].size)
++ if (cf->f->total + cf->f->offset - 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,
+ cf->f->total + cf->f->offset - start_offset);
3: a3d6177a352 = 3: 70af6e3083f commit-graph: use chunk-format write API
4: 9fe5ee8611c ! 4: 0cac7890bed midx: rename pack_info to write_midx_context
@@ midx.c: struct pack_list {
const char *file_name, void *data)
{
- struct pack_list *packs = (struct pack_list *)data;
-+ struct write_midx_context *ctx = (struct write_midx_context *)data;
++ struct write_midx_context *ctx = data;
if (ends_with(file_name, ".idx")) {
- display_progress(packs->progress, ++packs->pack_paths_checked);
5: 14a0246b982 ! 5: 4a4e90b129a midx: use context in write_midx_pack_names()
@@ midx.c: static struct pack_midx_entry *get_sorted_entries(struct multi_pack_inde
- uint32_t num_packs)
+static size_t write_midx_pack_names(struct hashfile *f, void *data)
{
-+ struct write_midx_context *ctx = (struct write_midx_context *)data;
++ struct write_midx_context *ctx = data;
uint32_t i;
unsigned char padding[MIDX_CHUNK_ALIGNMENT];
size_t written = 0;
6: 79f479ef7d1 ! 6: 30ad423997b midx: add entries to write_midx_context
@@ midx.c: static size_t write_midx_pack_names(struct hashfile *f, void *data)
{
- struct pack_midx_entry *list = objects;
- struct pack_midx_entry *last = objects + nr_objects;
-+ struct write_midx_context *ctx = (struct write_midx_context *)data;
++ struct write_midx_context *ctx = data;
+ struct pack_midx_entry *list = ctx->entries;
+ struct pack_midx_entry *last = ctx->entries + ctx->entries_nr;
uint32_t count = 0;
@@ midx.c: static size_t write_midx_oid_fanout(struct hashfile *f,
+ void *data)
{
- struct pack_midx_entry *list = objects;
-+ struct write_midx_context *ctx = (struct write_midx_context *)data;
++ struct write_midx_context *ctx = data;
+ unsigned char hash_len = the_hash_algo->rawsz;
+ struct pack_midx_entry *list = ctx->entries;
uint32_t i;
7: 0b4ce3f1732 ! 7: 2f1c496f3ab midx: add pack_perm to write_midx_context
@@ midx.c: static size_t write_midx_oid_lookup(struct hashfile *f,
+ void *data)
{
- struct pack_midx_entry *list = objects;
-+ struct write_midx_context *ctx = (struct write_midx_context *)data;
++ struct write_midx_context *ctx = data;
+ struct pack_midx_entry *list = ctx->entries;
uint32_t i, nr_large_offset = 0;
size_t written = 0;
8: eabc7b73647 ! 8: c4939548e51 midx: add num_large_offsets to write_midx_context
@@ midx.c: static size_t write_midx_object_offsets(struct hashfile *f,
+ void *data)
{
- struct pack_midx_entry *list = objects, *end = objects + nr_objects;
-+ struct write_midx_context *ctx = (struct write_midx_context *)data;
++ struct write_midx_context *ctx = data;
+ struct pack_midx_entry *list = ctx->entries;
+ struct pack_midx_entry *end = ctx->entries + ctx->entries_nr;
size_t written = 0;
9: 909ca28e0ba ! 9: b3cc73c2256 midx: return success/failure in chunk write methods
@@ midx.c: static struct pack_midx_entry *get_sorted_entries(struct multi_pack_inde
-static size_t write_midx_pack_names(struct hashfile *f, void *data)
+static int write_midx_pack_names(struct hashfile *f, void *data)
{
- struct write_midx_context *ctx = (struct write_midx_context *)data;
+ struct write_midx_context *ctx = data;
uint32_t i;
@@ midx.c: static size_t write_midx_pack_names(struct hashfile *f, void *data)
if (i < MIDX_CHUNK_ALIGNMENT) {
@@ midx.c: static size_t write_midx_pack_names(struct hashfile *f, void *data)
+static int write_midx_oid_fanout(struct hashfile *f,
+ void *data)
{
- struct write_midx_context *ctx = (struct write_midx_context *)data;
+ struct write_midx_context *ctx = data;
struct pack_midx_entry *list = ctx->entries;
@@ midx.c: static size_t write_midx_oid_fanout(struct hashfile *f,
list = next;
@@ midx.c: static size_t write_midx_oid_fanout(struct hashfile *f,
+static int write_midx_oid_lookup(struct hashfile *f,
+ void *data)
{
- struct write_midx_context *ctx = (struct write_midx_context *)data;
+ struct write_midx_context *ctx = data;
unsigned char hash_len = the_hash_algo->rawsz;
struct pack_midx_entry *list = ctx->entries;
uint32_t i;
@@ midx.c: static size_t write_midx_oid_lookup(struct hashfile *f,
+static int write_midx_object_offsets(struct hashfile *f,
+ void *data)
{
- struct write_midx_context *ctx = (struct write_midx_context *)data;
+ struct write_midx_context *ctx = data;
struct pack_midx_entry *list = ctx->entries;
uint32_t i, nr_large_offset = 0;
- size_t written = 0;
@@ midx.c: static size_t write_midx_object_offsets(struct hashfile *f,
+static int write_midx_large_offsets(struct hashfile *f,
+ void *data)
{
- struct write_midx_context *ctx = (struct write_midx_context *)data;
+ struct write_midx_context *ctx = data;
struct pack_midx_entry *list = ctx->entries;
struct pack_midx_entry *end = ctx->entries + ctx->entries_nr;
- size_t written = 0;
10: e613ffa9ac6 = 10: 78744d3b701 midx: drop chunk progress during write
11: 49cfb4f63e2 = 11: 07dc0cf8c68 midx: use chunk-format API in write_midx_internal()
12: e3475633e1d ! 12: d8d8e9e2aa3 chunk-format: create read chunk API
@@ Commit message
1. initialize a 'struct chunkfile' with init_chunkfile(NULL).
2. call read_table_of_contents().
- 3. for each chunk to parse, call pair_chunk() with appropriate pointers.
+ 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
@@ chunk-format.c: int write_chunkfile(struct chunkfile *cf, void *data)
+
+int pair_chunk(struct chunkfile *cf,
+ uint32_t chunk_id,
++ const unsigned char **p)
++{
++ int i;
++
++ for (i = 0; i < cf->chunks_nr; i++) {
++ if (cf->chunks[i].id == chunk_id) {
++ *p = cf->chunks[i].start;
++ return 0;
++ }
++ }
++
++ return CHUNK_NOT_FOUND;
++}
++
++int read_chunk(struct chunkfile *cf,
++ uint32_t chunk_id,
+ chunk_read_fn fn,
+ void *data)
+{
@@ chunk-format.h: void add_chunk(struct chunkfile *cf,
+ uint64_t toc_offset,
+ int toc_length);
+
++#define CHUNK_NOT_FOUND (-2)
++
+/*
-+ * When reading a table of contents, we find the chunk with matching 'id'
-+ * then call its read_fn to populate the necessary 'data' based on the
-+ * chunk start and size.
++ * 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);
-+
-+
-+#define CHUNK_NOT_FOUND (-2)
-+int pair_chunk(struct chunkfile *cf,
++/*
++ * 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);
13: 7339990f07d ! 13: 8744d278596 commit-graph: use chunk-format read API
@@ commit-graph.c: static int verify_commit_graph_lite(struct commit_graph *g)
return 0;
}
-+static int graph_read_oid_fanout(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct commit_graph *g = (struct commit_graph *)data;
-+ g->chunk_oid_fanout = (uint32_t*)chunk_start;
-+ return 0;
-+}
-+
+static int graph_read_oid_lookup(const unsigned char *chunk_start,
+ size_t chunk_size, void *data)
+{
-+ struct commit_graph *g = (struct commit_graph *)data;
++ struct commit_graph *g = data;
+ g->chunk_oid_lookup = chunk_start;
+ g->num_commits = chunk_size / g->hash_len;
+ return 0;
+}
+
-+static int graph_read_data(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct commit_graph *g = (struct commit_graph *)data;
-+ g->chunk_commit_data = chunk_start;
-+ return 0;
-+}
-+
-+static int graph_read_extra_edges(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct commit_graph *g = (struct commit_graph *)data;
-+ g->chunk_extra_edges = chunk_start;
-+ return 0;
-+}
-+
-+static int graph_read_base_graphs(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct commit_graph *g = (struct commit_graph *)data;
-+ g->chunk_base_graphs = chunk_start;
-+ return 0;
-+}
-+
-+static int graph_read_generation_data(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct commit_graph *g = (struct commit_graph *)data;
-+ g->chunk_generation_data = chunk_start;
-+ return 0;
-+}
-+
-+static int graph_read_generation_overflow(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct commit_graph *g = (struct commit_graph *)data;
-+ g->chunk_generation_data_overflow = chunk_start;
-+ return 0;
-+}
-+
-+static int graph_read_bloom_indices(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct commit_graph *g = (struct commit_graph *)data;
-+ g->chunk_bloom_indexes = chunk_start;
-+ return 0;
-+}
-+
+static int graph_read_bloom_data(const unsigned char *chunk_start,
+ size_t chunk_size, void *data)
+{
-+ struct commit_graph *g = (struct commit_graph *)data;
++ struct commit_graph *g = data;
+ uint32_t hash_version;
+ g->chunk_bloom_data = chunk_start;
+ hash_version = get_be32(chunk_start);
@@ commit-graph.c: struct commit_graph *parse_commit_graph(struct repository *r,
- / graph->hash_len;
- }
- break;
--
++ cf = init_chunkfile(NULL);
+
- case GRAPH_CHUNKID_DATA:
- if (graph->chunk_commit_data)
- chunk_repeated = 1;
@@ commit-graph.c: struct commit_graph *parse_commit_graph(struct repository *r,
- else
- graph->chunk_generation_data = data + chunk_offset;
- break;
-+ cf = init_chunkfile(NULL);
-
+-
- case GRAPH_CHUNKID_GENERATION_DATA_OVERFLOW:
- if (graph->chunk_generation_data_overflow)
- chunk_repeated = 1;
@@ commit-graph.c: struct commit_graph *parse_commit_graph(struct repository *r,
- }
- break;
- }
-+ pair_chunk(cf, GRAPH_CHUNKID_OIDFANOUT, graph_read_oid_fanout, graph);
-+ pair_chunk(cf, GRAPH_CHUNKID_OIDLOOKUP, graph_read_oid_lookup, graph);
-+ pair_chunk(cf, GRAPH_CHUNKID_DATA, graph_read_data, graph);
-+ pair_chunk(cf, GRAPH_CHUNKID_EXTRAEDGES, graph_read_extra_edges, graph);
-+ pair_chunk(cf, GRAPH_CHUNKID_BASE, graph_read_base_graphs, graph);
++ pair_chunk(cf, GRAPH_CHUNKID_OIDFANOUT,
++ (const unsigned char **)&graph->chunk_oid_fanout);
++ read_chunk(cf, GRAPH_CHUNKID_OIDLOOKUP, graph_read_oid_lookup, graph);
++ pair_chunk(cf, GRAPH_CHUNKID_DATA, &graph->chunk_commit_data);
++ pair_chunk(cf, GRAPH_CHUNKID_EXTRAEDGES, &graph->chunk_extra_edges);
++ pair_chunk(cf, GRAPH_CHUNKID_BASE, &graph->chunk_base_graphs);
+ pair_chunk(cf, GRAPH_CHUNKID_GENERATION_DATA,
-+ graph_read_generation_data, graph);
++ &graph->chunk_generation_data);
+ pair_chunk(cf, GRAPH_CHUNKID_GENERATION_DATA_OVERFLOW,
-+ graph_read_generation_overflow, graph);
++ &graph->chunk_generation_data_overflow);
- if (chunk_repeated) {
- error(_("commit-graph chunk id %08x appears multiple times"), chunk_id);
@@ commit-graph.c: struct commit_graph *parse_commit_graph(struct repository *r,
- }
+ if (r->settings.commit_graph_read_changed_paths) {
+ pair_chunk(cf, GRAPH_CHUNKID_BLOOMINDEXES,
-+ graph_read_bloom_indices, graph);
-+ pair_chunk(cf, GRAPH_CHUNKID_BLOOMDATA,
++ &graph->chunk_bloom_indexes);
++ read_chunk(cf, GRAPH_CHUNKID_BLOOMDATA,
+ graph_read_bloom_data, graph);
}
14: cb145e0e32a ! 14: 750c03253c9 midx: use chunk-format read API
@@ midx.c: static char *get_midx_filename(const char *object_dir)
return xstrfmt("%s/pack/multi-pack-index", object_dir);
}
-+static int midx_read_pack_names(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct multi_pack_index *m = (struct multi_pack_index *)data;
-+ m->chunk_pack_names = chunk_start;
-+ return 0;
-+}
-+
+static int midx_read_oid_fanout(const unsigned char *chunk_start,
+ size_t chunk_size, void *data)
+{
-+ struct multi_pack_index *m = (struct multi_pack_index *)data;
++ struct multi_pack_index *m = data;
+ m->chunk_oid_fanout = (uint32_t *)chunk_start;
+
+ if (chunk_size != 4 * 256) {
@@ midx.c: static char *get_midx_filename(const char *object_dir)
+ }
+ return 0;
+}
-+
-+static int midx_read_oid_lookup(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct multi_pack_index *m = (struct multi_pack_index *)data;
-+ m->chunk_oid_lookup = chunk_start;
-+ return 0;
-+}
-+
-+static int midx_read_offsets(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct multi_pack_index *m = (struct multi_pack_index *)data;
-+ m->chunk_object_offsets = chunk_start;
-+ return 0;
-+}
-+
-+static int midx_read_large_offsets(const unsigned char *chunk_start,
-+ size_t chunk_size, void *data)
-+{
-+ struct multi_pack_index *m = (struct multi_pack_index *)data;
-+ m->chunk_large_offsets = chunk_start;
-+ return 0;
-+}
+
struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local)
{
@@ midx.c: struct multi_pack_index *load_multi_pack_index(const char *object_dir, i
+ MIDX_HEADER_SIZE, m->num_chunks))
+ goto cleanup_fail;
+
-+ if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, midx_read_pack_names, m) == CHUNK_NOT_FOUND)
++ if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, &m->chunk_pack_names) == CHUNK_NOT_FOUND)
die(_("multi-pack-index missing required pack-name chunk"));
- if (!m->chunk_oid_fanout)
-+ if (pair_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m) == CHUNK_NOT_FOUND)
++ if (read_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m) == CHUNK_NOT_FOUND)
die(_("multi-pack-index missing required OID fanout chunk"));
- if (!m->chunk_oid_lookup)
-+ if (pair_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, midx_read_oid_lookup, m) == CHUNK_NOT_FOUND)
++ if (pair_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, &m->chunk_oid_lookup) == CHUNK_NOT_FOUND)
die(_("multi-pack-index missing required OID lookup chunk"));
- if (!m->chunk_object_offsets)
-+ if (pair_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, midx_read_offsets, m) == CHUNK_NOT_FOUND)
++ if (pair_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, &m->chunk_object_offsets) == CHUNK_NOT_FOUND)
die(_("multi-pack-index missing required object offsets chunk"));
-+ pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, midx_read_large_offsets, m);
++ pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets);
+
m->num_objects = ntohl(m->chunk_oid_fanout[255]);
15: f6c58ff72d2 = 15: 83d292532a0 midx: use 64-bit multiplication for chunk sizes
16: 62a23842aa6 = 16: 669eeec707a chunk-format: restore duplicate chunk checks
17: 05cbd0a8d93 = 17: 8f3985ab5df chunk-format: add technical docs-- gitgitgadget