#include "cache.h"

#include "config.h"

#include "dir.h"

#include "git-compat-util.h"

#include "lockfile.h"

#include "pack.h"

#include "packfile.h"

#include "commit.h"

#include "object.h"

#include "refs.h"

#include "revision.h"

#include "sha1-lookup.h"

#include "commit-graph.h"

#include "object-store.h"

#include "alloc.h"

#include "hashmap.h"

#include "replace-object.h"

#include "progress.h"

#define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */

#define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */

#define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */

#define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */

#define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */

#define GRAPH_DATA_WIDTH 36

#define GRAPH_VERSION_1 0x1

#define GRAPH_VERSION GRAPH_VERSION_1

#define GRAPH_OID_VERSION_SHA1 1

#define GRAPH_OID_LEN_SHA1 GIT_SHA1_RAWSZ

#define GRAPH_OID_VERSION GRAPH_OID_VERSION_SHA1

#define GRAPH_OID_LEN GRAPH_OID_LEN_SHA1

#define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000

#define GRAPH_PARENT_MISSING 0x7fffffff

#define GRAPH_EDGE_LAST_MASK 0x7fffffff

#define GRAPH_PARENT_NONE 0x70000000

#define GRAPH_LAST_EDGE 0x80000000

#define GRAPH_HEADER_SIZE 8

#define GRAPH_FANOUT_SIZE (4 * 256)

#define GRAPH_CHUNKLOOKUP_WIDTH 12

#define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \

+ GRAPH_FANOUT_SIZE + GRAPH_OID_LEN)

char *get_commit_graph_filename(const char *obj_dir)

{

return xstrfmt("%s/info/commit-graph", obj_dir);

}

static struct commit_graph *alloc_commit_graph(void)

{

struct commit_graph *g = xcalloc(1, sizeof(*g));

g->graph_fd = -1;

return g;

}

extern int read_replace_refs;

static int commit_graph_compatible(struct repository *r)

{

if (!r->gitdir)

return 0;

if (read_replace_refs) {

prepare_replace_object(r);

if (hashmap_get_size(&r->objects->replace_map->map))

return 0;

}

prepare_commit_graft(r);

if (r->parsed_objects && r->parsed_objects->grafts_nr)

return 0;

if (is_repository_shallow(r))

return 0;

return 1;

}

struct commit_graph *load_commit_graph_one(const char *graph_file)

{

void *graph_map;

const unsigned char *data, *chunk_lookup;

size_t graph_size;

struct stat st;

uint32_t i;

struct commit_graph *graph;

int fd = git_open(graph_file);

uint64_t last_chunk_offset;

uint32_t last_chunk_id;

uint32_t graph_signature;

unsigned char graph_version, hash_version;

if (fd < 0)

return NULL;

if (fstat(fd, &st)) {

close(fd);

return NULL;

}

graph_size = xsize_t(st.st_size);

if (graph_size < GRAPH_MIN_SIZE) {

close(fd);

die(_("graph file %s is too small"), graph_file);

}

graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);

data = (const unsigned char *)graph_map;

graph_signature = get_be32(data);

if (graph_signature != GRAPH_SIGNATURE) {

error(_("graph signature %X does not match signature %X"),

graph_signature, GRAPH_SIGNATURE);

goto cleanup_fail;

}

graph_version = *(unsigned char*)(data + 4);

if (graph_version != GRAPH_VERSION) {

error(_("graph version %X does not match version %X"),

graph_version, GRAPH_VERSION);

goto cleanup_fail;

}

hash_version = *(unsigned char*)(data + 5);

if (hash_version != GRAPH_OID_VERSION) {

error(_("hash version %X does not match version %X"),

hash_version, GRAPH_OID_VERSION);

goto cleanup_fail;

}

graph = alloc_commit_graph();

graph->hash_len = GRAPH_OID_LEN;

graph->num_chunks = *(unsigned char*)(data + 6);

graph->graph_fd = fd;

graph->data = graph_map;

graph->data_len = graph_size;

last_chunk_id = 0;

last_chunk_offset = 8;

chunk_lookup = data + 8;

for (i = 0; i < graph->num_chunks; i++) {

uint32_t chunk_id = get_be32(chunk_lookup + 0);

uint64_t chunk_offset = get_be64(chunk_lookup + 4);

int chunk_repeated = 0;

chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;

if (chunk_offset > graph_size - GIT_MAX_RAWSZ) {

error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),

(uint32_t)chunk_offset);

goto cleanup_fail;

}

switch (chunk_id) {

case GRAPH_CHUNKID_OIDFANOUT:

if (graph->chunk_oid_fanout)

chunk_repeated = 1;

else

graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);

break;

case GRAPH_CHUNKID_OIDLOOKUP:

if (graph->chunk_oid_lookup)

chunk_repeated = 1;

else

graph->chunk_oid_lookup = data + chunk_offset;

break;

case GRAPH_CHUNKID_DATA:

if (graph->chunk_commit_data)

chunk_repeated = 1;

else

graph->chunk_commit_data = data + chunk_offset;

break;

case GRAPH_CHUNKID_LARGEEDGES:

if (graph->chunk_large_edges)

chunk_repeated = 1;

else

graph->chunk_large_edges = data + chunk_offset;

break;

}

if (chunk_repeated) {

error(_("chunk id %08x appears multiple times"), chunk_id);

goto cleanup_fail;

}

if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)

{

graph->num_commits = (chunk_offset - last_chunk_offset)

/ graph->hash_len;

}

last_chunk_id = chunk_id;

last_chunk_offset = chunk_offset;

}

return graph;

cleanup_fail:

munmap(graph_map, graph_size);

close(fd);

exit(1);

}

static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)

{

char *graph_name;

if (r->objects->commit_graph)

return;

graph_name = get_commit_graph_filename(obj_dir);

r->objects->commit_graph =

load_commit_graph_one(graph_name);

FREE_AND_NULL(graph_name);

}

static int prepare_commit_graph(struct repository *r)

{

struct alternate_object_database *alt;

char *obj_dir;

int config_value;

if (r->objects->commit_graph_attempted)

return !!r->objects->commit_graph;

r->objects->commit_graph_attempted = 1;

if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&

(repo_config_get_bool(r, "core.commitgraph", &config_value) ||

!config_value))

/*

return 0;

if (!commit_graph_compatible(r))

return 0;

obj_dir = r->objects->objectdir;

prepare_commit_graph_one(r, obj_dir);

prepare_alt_odb(r);

for (alt = r->objects->alt_odb_list;

!r->objects->commit_graph && alt;

alt = alt->next)

prepare_commit_graph_one(r, alt->path);

return !!r->objects->commit_graph;

}

int generation_numbers_enabled(struct repository *r)

{

uint32_t first_generation;

struct commit_graph *g;

if (!prepare_commit_graph(r))

return 0;

g = r->objects->commit_graph;

if (!g->num_commits)

return 0;

first_generation = get_be32(g->chunk_commit_data +

g->hash_len + 8) >> 2;

return !!first_generation;

}

void close_commit_graph(struct repository *r)

{

free_commit_graph(r->objects->commit_graph);

r->objects->commit_graph = NULL;

}

static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)

{

return bsearch_hash(oid->hash, g->chunk_oid_fanout,

g->chunk_oid_lookup, g->hash_len, pos);

}

static struct commit_list **insert_parent_or_die(struct commit_graph *g,

uint64_t pos,

struct commit_list **pptr)

{

struct commit *c;

struct object_id oid;

if (pos >= g->num_commits)

die("invalid parent position %"PRIu64, pos);

hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);

c = lookup_commit(the_repository, &oid);

if (!c)

die(_("could not find commit %s"), oid_to_hex(&oid));

c->graph_pos = pos;

return &commit_list_insert(c, pptr)->next;

}

static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)

{

const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;

item->graph_pos = pos;

item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;

}

static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)

{

uint32_t edge_value;

uint32_t *parent_data_ptr;

uint64_t date_low, date_high;

struct commit_list **pptr;

const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;

item->object.parsed = 1;

item->graph_pos = pos;

item->maybe_tree = NULL;

date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;

date_low = get_be32(commit_data + g->hash_len + 12);

item->date = (timestamp_t)((date_high << 32) | date_low);

item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;

pptr = &item->parents;

edge_value = get_be32(commit_data + g->hash_len);

if (edge_value == GRAPH_PARENT_NONE)

return 1;

pptr = insert_parent_or_die(g, edge_value, pptr);

edge_value = get_be32(commit_data + g->hash_len + 4);

if (edge_value == GRAPH_PARENT_NONE)

return 1;

if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {

pptr = insert_parent_or_die(g, edge_value, pptr);

return 1;

}

parent_data_ptr = (uint32_t*)(g->chunk_large_edges +

4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));

do {

edge_value = get_be32(parent_data_ptr);

pptr = insert_parent_or_die(g,

edge_value & GRAPH_EDGE_LAST_MASK,

pptr);

parent_data_ptr++;

} while (!(edge_value & GRAPH_LAST_EDGE));

return 1;

}

static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)

{

if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {

*pos = item->graph_pos;

return 1;

} else {

return bsearch_graph(g, &(item->object.oid), pos);

}

}

static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)

{

uint32_t pos;

if (item->object.parsed)

return 1;

if (find_commit_in_graph(item, g, &pos))

return fill_commit_in_graph(item, g, pos);

return 0;

}

int parse_commit_in_graph(struct repository *r, struct commit *item)

{

if (!prepare_commit_graph(r))

return 0;

return parse_commit_in_graph_one(r->objects->commit_graph, item);

}

void load_commit_graph_info(struct repository *r, struct commit *item)

{

uint32_t pos;

if (!prepare_commit_graph(r))

return;

if (find_commit_in_graph(item, r->objects->commit_graph, &pos))

fill_commit_graph_info(item, r->objects->commit_graph, pos);

}

static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)

{

struct object_id oid;

const unsigned char *commit_data = g->chunk_commit_data +

GRAPH_DATA_WIDTH * (c->graph_pos);

hashcpy(oid.hash, commit_data);

c->maybe_tree = lookup_tree(the_repository, &oid);

return c->maybe_tree;

}

static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,

const struct commit *c)

{

if (c->maybe_tree)

return c->maybe_tree;

if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)

BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");

return load_tree_for_commit(g, (struct commit *)c);

}

struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)

{

return get_commit_tree_in_graph_one(r->objects->commit_graph, c);

}

static void write_graph_chunk_fanout(struct hashfile *f,

struct commit **commits,

int nr_commits)

{

int i, count = 0;

struct commit **list = commits;

/*

for (i = 0; i < 256; i++) {

while (count < nr_commits) {

if ((*list)->object.oid.hash[0] != i)

break;

count++;

list++;

}

hashwrite_be32(f, count);

}

}

static void write_graph_chunk_oids(struct hashfile *f, int hash_len,

struct commit **commits, int nr_commits)

{

struct commit **list = commits;

int count;

for (count = 0; count < nr_commits; count++, list++)

hashwrite(f, (*list)->object.oid.hash, (int)hash_len);

}

static const unsigned char *commit_to_sha1(size_t index, void *table)

{

struct commit **commits = table;

return commits[index]->object.oid.hash;

}

static void write_graph_chunk_data(struct hashfile *f, int hash_len,

struct commit **commits, int nr_commits)

{

struct commit **list = commits;

struct commit **last = commits + nr_commits;

uint32_t num_extra_edges = 0;

while (list < last) {

struct commit_list *parent;

int edge_value;

uint32_t packedDate[2];

parse_commit(*list);

hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);

parent = (*list)->parents;

if (!parent)

edge_value = GRAPH_PARENT_NONE;

else {

edge_value = sha1_pos(parent->item->object.oid.hash,

commits,

nr_commits,

commit_to_sha1);

if (edge_value < 0)

edge_value = GRAPH_PARENT_MISSING;

}

hashwrite_be32(f, edge_value);

if (parent)

parent = parent->next;

if (!parent)

edge_value = GRAPH_PARENT_NONE;

else if (parent->next)

edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;

else {

edge_value = sha1_pos(parent->item->object.oid.hash,

commits,

nr_commits,

commit_to_sha1);

if (edge_value < 0)

edge_value = GRAPH_PARENT_MISSING;

}

hashwrite_be32(f, edge_value);

if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {

do {

num_extra_edges++;

parent = parent->next;

} while (parent);

}

if (sizeof((*list)->date) > 4)

packedDate[0] = htonl(((*list)->date >> 32) & 0x3);

else

packedDate[0] = 0;

packedDate[0] |= htonl((*list)->generation << 2);

packedDate[1] = htonl((*list)->date);

hashwrite(f, packedDate, 8);

list++;

}

}

static void write_graph_chunk_large_edges(struct hashfile *f,

struct commit **commits,

int nr_commits)

{

struct commit **list = commits;

struct commit **last = commits + nr_commits;

struct commit_list *parent;

while (list < last) {

int num_parents = 0;

for (parent = (*list)->parents; num_parents < 3 && parent;

parent = parent->next)

num_parents++;

if (num_parents <= 2) {

list++;

continue;

}

/* Since num_parents > 2, this initializer is safe. */

for (parent = (*list)->parents->next; parent; parent = parent->next) {

int edge_value = sha1_pos(parent->item->object.oid.hash,

commits,

nr_commits,

commit_to_sha1);

if (edge_value < 0)

edge_value = GRAPH_PARENT_MISSING;

else if (!parent->next)

edge_value |= GRAPH_LAST_EDGE;

hashwrite_be32(f, edge_value);

}

list++;

}

}

static int commit_compare(const void *_a, const void *_b)

{

const struct object_id *a = (const struct object_id *)_a;

const struct object_id *b = (const struct object_id *)_b;

return oidcmp(a, b);

}

struct packed_commit_list {

};

struct packed_oid_list {

};

static int add_packed_commits(const struct object_id *oid,

struct packed_git *pack,

uint32_t pos,

void *data)

{

struct packed_oid_list *list = (struct packed_oid_list*)data;

enum object_type type;

off_t offset = nth_packed_object_offset(pack, pos);

struct object_info oi = OBJECT_INFO_INIT;

if (list->progress)

display_progress(list->progress, ++list->progress_done);

oi.typep = &type;

if (packed_object_info(the_repository, pack, offset, &oi) < 0)

die(_("unable to get type of object %s"), oid_to_hex(oid));

if (type != OBJ_COMMIT)

return 0;

ALLOC_GROW(list->list, list->nr + 1, list->alloc);

oidcpy(&(list->list[list->nr]), oid);

list->nr++;

return 0;

}

static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)

{

struct commit_list *parent;

for (parent = commit->parents; parent; parent = parent->next) {

if (!(parent->item->object.flags & UNINTERESTING)) {

ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);

oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));

oids->nr++;

parent->item->object.flags |= UNINTERESTING;

}

}

}

static void close_reachable(struct packed_oid_list *oids, int report_progress)

{

int i;

struct commit *commit;

struct progress *progress = NULL;

int j = 0;

if (report_progress)

progress = start_delayed_progress(

_("Annotating commits in commit graph"), 0);

for (i = 0; i < oids->nr; i++) {

display_progress(progress, ++j);

commit = lookup_commit(the_repository, &oids->list[i]);

if (commit)

commit->object.flags |= UNINTERESTING;

}

/*

for (i = 0; i < oids->nr; i++) {

display_progress(progress, ++j);

commit = lookup_commit(the_repository, &oids->list[i]);

if (commit && !parse_commit(commit))

add_missing_parents(oids, commit);

}

for (i = 0; i < oids->nr; i++) {

display_progress(progress, ++j);

commit = lookup_commit(the_repository, &oids->list[i]);

if (commit)

commit->object.flags &= ~UNINTERESTING;

}

stop_progress(&progress);

}

static void compute_generation_numbers(struct packed_commit_list* commits,

int report_progress)

{

int i;

struct commit_list *list = NULL;

struct progress *progress = NULL;

if (report_progress)

progress = start_progress(

_("Computing commit graph generation numbers"),

commits->nr);

for (i = 0; i < commits->nr; i++) {

display_progress(progress, i + 1);

if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&

commits->list[i]->generation != GENERATION_NUMBER_ZERO)

continue;

commit_list_insert(commits->list[i], &list);

while (list) {

struct commit *current = list->item;

struct commit_list *parent;

int all_parents_computed = 1;

uint32_t max_generation = 0;

for (parent = current->parents; parent; parent = parent->next) {

if (parent->item->generation == GENERATION_NUMBER_INFINITY ||

parent->item->generation == GENERATION_NUMBER_ZERO) {

all_parents_computed = 0;

commit_list_insert(parent->item, &list);

break;

} else if (parent->item->generation > max_generation) {

max_generation = parent->item->generation;

}

}

if (all_parents_computed) {

current->generation = max_generation + 1;

pop_commit(&list);

if (current->generation > GENERATION_NUMBER_MAX)

current->generation = GENERATION_NUMBER_MAX;

}

}

}

stop_progress(&progress);

}

static int add_ref_to_list(const char *refname,

const struct object_id *oid,

int flags, void *cb_data)

{

struct string_list *list = (struct string_list *)cb_data;

string_list_append(list, oid_to_hex(oid));

return 0;

}

void write_commit_graph_reachable(const char *obj_dir, int append,

int report_progress)

{

struct string_list list = STRING_LIST_INIT_DUP;

for_each_ref(add_ref_to_list, &list);

write_commit_graph(obj_dir, NULL, &list, append, report_progress);

string_list_clear(&list, 0);

}

void write_commit_graph(const char *obj_dir,

struct string_list *pack_indexes,

struct string_list *commit_hex,

int append, int report_progress)

{

struct packed_oid_list oids;

struct packed_commit_list commits;

struct hashfile *f;

uint32_t i, count_distinct = 0;

char *graph_name;

struct lock_file lk = LOCK_INIT;

uint32_t chunk_ids[5];

uint64_t chunk_offsets[5];

int num_chunks;

int num_extra_edges;

struct commit_list *parent;

struct progress *progress = NULL;

if (!commit_graph_compatible(the_repository))

return;

oids.nr = 0;

oids.alloc = approximate_object_count() / 32;

oids.progress = NULL;

oids.progress_done = 0;

if (append) {

prepare_commit_graph_one(the_repository, obj_dir);

if (the_repository->objects->commit_graph)

oids.alloc += the_repository->objects->commit_graph->num_commits;

}

if (oids.alloc < 1024)

oids.alloc = 1024;

ALLOC_ARRAY(oids.list, oids.alloc);

if (append && the_repository->objects->commit_graph) {

struct commit_graph *commit_graph =

the_repository->objects->commit_graph;

for (i = 0; i < commit_graph->num_commits; i++) {

const unsigned char *hash = commit_graph->chunk_oid_lookup +

commit_graph->hash_len * i;

hashcpy(oids.list[oids.nr++].hash, hash);

}

}

if (pack_indexes) {

struct strbuf packname = STRBUF_INIT;

int dirlen;

strbuf_addf(&packname, "%s/pack/", obj_dir);

dirlen = packname.len;

if (report_progress) {

oids.progress = start_delayed_progress(

_("Finding commits for commit graph"), 0);

oids.progress_done = 0;

}

for (i = 0; i < pack_indexes->nr; i++) {

struct packed_git *p;

strbuf_setlen(&packname, dirlen);

strbuf_addstr(&packname, pack_indexes->items[i].string);

p = add_packed_git(packname.buf, packname.len, 1);

if (!p)

die(_("error adding pack %s"), packname.buf);

if (open_pack_index(p))

die(_("error opening index for %s"), packname.buf);

for_each_object_in_pack(p, add_packed_commits, &oids, 0);

close_pack(p);

free(p);

}

stop_progress(&oids.progress);

strbuf_release(&packname);

}

if (commit_hex) {

if (report_progress)

progress = start_delayed_progress(

_("Finding commits for commit graph"),

commit_hex->nr);

for (i = 0; i < commit_hex->nr; i++) {

const char *end;

struct object_id oid;

struct commit *result;

display_progress(progress, i + 1);

if (commit_hex->items[i].string &&

parse_oid_hex(commit_hex->items[i].string, &oid, &end))

continue;

result = lookup_commit_reference_gently(the_repository, &oid, 1);

if (result) {

ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);

oidcpy(&oids.list[oids.nr], &(result->object.oid));

oids.nr++;

}

}

stop_progress(&progress);

}

if (!pack_indexes && !commit_hex) {

if (report_progress)

oids.progress = start_delayed_progress(

_("Finding commits for commit graph"), 0);

for_each_packed_object(add_packed_commits, &oids, 0);

stop_progress(&oids.progress);

}

close_reachable(&oids, report_progress);

QSORT(oids.list, oids.nr, commit_compare);

count_distinct = 1;

for (i = 1; i < oids.nr; i++) {

if (!oideq(&oids.list[i - 1], &oids.list[i]))

count_distinct++;

}

if (count_distinct >= GRAPH_PARENT_MISSING)

die(_("the commit graph format cannot write %d commits"), count_distinct);

commits.nr = 0;

commits.alloc = count_distinct;

ALLOC_ARRAY(commits.list, commits.alloc);

num_extra_edges = 0;

for (i = 0; i < oids.nr; i++) {

int num_parents = 0;

if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))

continue;

commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);

parse_commit(commits.list[commits.nr]);

for (parent = commits.list[commits.nr]->parents;

parent; parent = parent->next)

num_parents++;

if (num_parents > 2)

num_extra_edges += num_parents - 1;

commits.nr++;

}

num_chunks = num_extra_edges ? 4 : 3;

if (commits.nr >= GRAPH_PARENT_MISSING)

die(_("too many commits to write graph"));

compute_generation_numbers(&commits, report_progress);

graph_name = get_commit_graph_filename(obj_dir);

if (safe_create_leading_directories(graph_name)) {

UNLEAK(graph_name);

die_errno(_("unable to create leading directories of %s"),

graph_name);

}

hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);

f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);

hashwrite_be32(f, GRAPH_SIGNATURE);

hashwrite_u8(f, GRAPH_VERSION);

hashwrite_u8(f, GRAPH_OID_VERSION);

hashwrite_u8(f, num_chunks);

hashwrite_u8(f, 0); /* unused padding byte */

chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;

chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;

chunk_ids[2] = GRAPH_CHUNKID_DATA;

if (num_extra_edges)

chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;

else

chunk_ids[3] = 0;

chunk_ids[4] = 0;

chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;

chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;

chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;

chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;

chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;

for (i = 0; i <= num_chunks; i++) {

uint32_t chunk_write[3];

chunk_write[0] = htonl(chunk_ids[i]);

chunk_write[1] = htonl(chunk_offsets[i] >> 32);

chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);

hashwrite(f, chunk_write, 12);

}

write_graph_chunk_fanout(f, commits.list, commits.nr);

write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);

write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);

write_graph_chunk_large_edges(f, commits.list, commits.nr);

close_commit_graph(the_repository);

finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);

commit_lock_file(&lk);

free(graph_name);

free(commits.list);

free(oids.list);

}

#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2

static int verify_commit_graph_error;

static void graph_report(const char *fmt, ...)

{

va_list ap;

verify_commit_graph_error = 1;

va_start(ap, fmt);

vfprintf(stderr, fmt, ap);

fprintf(stderr, "\n");

va_end(ap);

}

#define GENERATION_ZERO_EXISTS 1

#define GENERATION_NUMBER_EXISTS 2

int verify_commit_graph(struct repository *r, struct commit_graph *g)

{

uint32_t i, cur_fanout_pos = 0;

struct object_id prev_oid, cur_oid, checksum;

int generation_zero = 0;

struct hashfile *f;

int devnull;

struct progress *progress = NULL;

if (!g) {

graph_report("no commit-graph file loaded");

return 1;

}

verify_commit_graph_error = 0;

if (!g->chunk_oid_fanout)

graph_report("commit-graph is missing the OID Fanout chunk");

if (!g->chunk_oid_lookup)

graph_report("commit-graph is missing the OID Lookup chunk");

if (!g->chunk_commit_data)

graph_report("commit-graph is missing the Commit Data chunk");

if (verify_commit_graph_error)

return verify_commit_graph_error;

devnull = open("/dev/null", O_WRONLY);

f = hashfd(devnull, NULL);

hashwrite(f, g->data, g->data_len - g->hash_len);

finalize_hashfile(f, checksum.hash, CSUM_CLOSE);