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midx.c
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#include "git-compat-util.h"
#include "abspath.h"
#include "config.h"
#include "csum-file.h"
#include "dir.h"
#include "gettext.h"
#include "hex.h"
#include "lockfile.h"
#include "packfile.h"
#include "object-file.h"
#include "object-store-ll.h"
#include "hash-lookup.h"
#include "midx.h"
#include "progress.h"
#include "trace2.h"
#include "run-command.h"
#include "repository.h"
#include "chunk-format.h"
#include "pack.h"
#include "pack-bitmap.h"
#include "refs.h"
#include "revision.h"
#include "list-objects.h"
#define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
#define MIDX_VERSION 1
#define MIDX_BYTE_FILE_VERSION 4
#define MIDX_BYTE_HASH_VERSION 5
#define MIDX_BYTE_NUM_CHUNKS 6
#define MIDX_BYTE_NUM_PACKS 8
#define MIDX_HEADER_SIZE 12
#define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + the_hash_algo->rawsz)
#define MIDX_CHUNK_ALIGNMENT 4
#define MIDX_CHUNKID_PACKNAMES 0x504e414d /* "PNAM" */
#define MIDX_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
#define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
#define MIDX_CHUNKID_OBJECTOFFSETS 0x4f4f4646 /* "OOFF" */
#define MIDX_CHUNKID_LARGEOFFSETS 0x4c4f4646 /* "LOFF" */
#define MIDX_CHUNKID_REVINDEX 0x52494458 /* "RIDX" */
#define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256)
#define MIDX_CHUNK_OFFSET_WIDTH (2 * sizeof(uint32_t))
#define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t))
#define MIDX_LARGE_OFFSET_NEEDED 0x80000000
#define PACK_EXPIRED UINT_MAX
const unsigned char *get_midx_checksum(struct multi_pack_index *m)
{
return m->data + m->data_len - the_hash_algo->rawsz;
}
void get_midx_filename(struct strbuf *out, const char *object_dir)
{
strbuf_addf(out, "%s/pack/multi-pack-index", object_dir);
}
void get_midx_rev_filename(struct strbuf *out, struct multi_pack_index *m)
{
get_midx_filename(out, m->object_dir);
strbuf_addf(out, "-%s.rev", hash_to_hex(get_midx_checksum(m)));
}
static int midx_read_oid_fanout(const unsigned char *chunk_start,
size_t chunk_size, void *data)
{
int i;
struct multi_pack_index *m = data;
m->chunk_oid_fanout = (uint32_t *)chunk_start;
if (chunk_size != 4 * 256) {
error(_("multi-pack-index OID fanout is of the wrong size"));
return 1;
}
for (i = 0; i < 255; i++) {
uint32_t oid_fanout1 = ntohl(m->chunk_oid_fanout[i]);
uint32_t oid_fanout2 = ntohl(m->chunk_oid_fanout[i+1]);
if (oid_fanout1 > oid_fanout2) {
error(_("oid fanout out of order: fanout[%d] = %"PRIx32" > %"PRIx32" = fanout[%d]"),
i, oid_fanout1, oid_fanout2, i + 1);
return 1;
}
}
m->num_objects = ntohl(m->chunk_oid_fanout[255]);
return 0;
}
static int midx_read_oid_lookup(const unsigned char *chunk_start,
size_t chunk_size, void *data)
{
struct multi_pack_index *m = data;
m->chunk_oid_lookup = chunk_start;
if (chunk_size != st_mult(m->hash_len, m->num_objects)) {
error(_("multi-pack-index OID lookup chunk is the wrong size"));
return 1;
}
return 0;
}
static int midx_read_object_offsets(const unsigned char *chunk_start,
size_t chunk_size, void *data)
{
struct multi_pack_index *m = data;
m->chunk_object_offsets = chunk_start;
if (chunk_size != st_mult(m->num_objects, MIDX_CHUNK_OFFSET_WIDTH)) {
error(_("multi-pack-index object offset chunk is the wrong size"));
return 1;
}
return 0;
}
struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local)
{
struct multi_pack_index *m = NULL;
int fd;
struct stat st;
size_t midx_size;
void *midx_map = NULL;
uint32_t hash_version;
struct strbuf midx_name = STRBUF_INIT;
uint32_t i;
const char *cur_pack_name;
struct chunkfile *cf = NULL;
get_midx_filename(&midx_name, object_dir);
fd = git_open(midx_name.buf);
if (fd < 0)
goto cleanup_fail;
if (fstat(fd, &st)) {
error_errno(_("failed to read %s"), midx_name.buf);
goto cleanup_fail;
}
midx_size = xsize_t(st.st_size);
if (midx_size < MIDX_MIN_SIZE) {
error(_("multi-pack-index file %s is too small"), midx_name.buf);
goto cleanup_fail;
}
strbuf_release(&midx_name);
midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
FLEX_ALLOC_STR(m, object_dir, object_dir);
m->data = midx_map;
m->data_len = midx_size;
m->local = local;
m->signature = get_be32(m->data);
if (m->signature != MIDX_SIGNATURE)
die(_("multi-pack-index signature 0x%08x does not match signature 0x%08x"),
m->signature, MIDX_SIGNATURE);
m->version = m->data[MIDX_BYTE_FILE_VERSION];
if (m->version != MIDX_VERSION)
die(_("multi-pack-index version %d not recognized"),
m->version);
hash_version = m->data[MIDX_BYTE_HASH_VERSION];
if (hash_version != oid_version(the_hash_algo)) {
error(_("multi-pack-index hash version %u does not match version %u"),
hash_version, oid_version(the_hash_algo));
goto cleanup_fail;
}
m->hash_len = the_hash_algo->rawsz;
m->num_chunks = m->data[MIDX_BYTE_NUM_CHUNKS];
m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS);
cf = init_chunkfile(NULL);
if (read_table_of_contents(cf, m->data, midx_size,
MIDX_HEADER_SIZE, m->num_chunks,
MIDX_CHUNK_ALIGNMENT))
goto cleanup_fail;
if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, &m->chunk_pack_names, &m->chunk_pack_names_len))
die(_("multi-pack-index required pack-name chunk missing or corrupted"));
if (read_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m))
die(_("multi-pack-index required OID fanout chunk missing or corrupted"));
if (read_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, midx_read_oid_lookup, m))
die(_("multi-pack-index required OID lookup chunk missing or corrupted"));
if (read_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, midx_read_object_offsets, m))
die(_("multi-pack-index required object offsets chunk missing or corrupted"));
pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets,
&m->chunk_large_offsets_len);
if (git_env_bool("GIT_TEST_MIDX_READ_RIDX", 1))
pair_chunk(cf, MIDX_CHUNKID_REVINDEX, &m->chunk_revindex,
&m->chunk_revindex_len);
CALLOC_ARRAY(m->pack_names, m->num_packs);
CALLOC_ARRAY(m->packs, m->num_packs);
cur_pack_name = (const char *)m->chunk_pack_names;
for (i = 0; i < m->num_packs; i++) {
const char *end;
size_t avail = m->chunk_pack_names_len -
(cur_pack_name - (const char *)m->chunk_pack_names);
m->pack_names[i] = cur_pack_name;
end = memchr(cur_pack_name, '\0', avail);
if (!end)
die(_("multi-pack-index pack-name chunk is too short"));
cur_pack_name = end + 1;
if (i && strcmp(m->pack_names[i], m->pack_names[i - 1]) <= 0)
die(_("multi-pack-index pack names out of order: '%s' before '%s'"),
m->pack_names[i - 1],
m->pack_names[i]);
}
trace2_data_intmax("midx", the_repository, "load/num_packs", m->num_packs);
trace2_data_intmax("midx", the_repository, "load/num_objects", m->num_objects);
free_chunkfile(cf);
return m;
cleanup_fail:
free(m);
strbuf_release(&midx_name);
free_chunkfile(cf);
if (midx_map)
munmap(midx_map, midx_size);
if (0 <= fd)
close(fd);
return NULL;
}
void close_midx(struct multi_pack_index *m)
{
uint32_t i;
if (!m)
return;
close_midx(m->next);
munmap((unsigned char *)m->data, m->data_len);
for (i = 0; i < m->num_packs; i++) {
if (m->packs[i])
m->packs[i]->multi_pack_index = 0;
}
FREE_AND_NULL(m->packs);
FREE_AND_NULL(m->pack_names);
free(m);
}
int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id)
{
struct strbuf pack_name = STRBUF_INIT;
struct packed_git *p;
if (pack_int_id >= m->num_packs)
die(_("bad pack-int-id: %u (%u total packs)"),
pack_int_id, m->num_packs);
if (m->packs[pack_int_id])
return 0;
strbuf_addf(&pack_name, "%s/pack/%s", m->object_dir,
m->pack_names[pack_int_id]);
p = add_packed_git(pack_name.buf, pack_name.len, m->local);
strbuf_release(&pack_name);
if (!p)
return 1;
p->multi_pack_index = 1;
m->packs[pack_int_id] = p;
install_packed_git(r, p);
list_add_tail(&p->mru, &r->objects->packed_git_mru);
return 0;
}
int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result)
{
return bsearch_hash(oid->hash, m->chunk_oid_fanout, m->chunk_oid_lookup,
the_hash_algo->rawsz, result);
}
struct object_id *nth_midxed_object_oid(struct object_id *oid,
struct multi_pack_index *m,
uint32_t n)
{
if (n >= m->num_objects)
return NULL;
oidread(oid, m->chunk_oid_lookup + st_mult(m->hash_len, n));
return oid;
}
off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos)
{
const unsigned char *offset_data;
uint32_t offset32;
offset_data = m->chunk_object_offsets + (off_t)pos * MIDX_CHUNK_OFFSET_WIDTH;
offset32 = get_be32(offset_data + sizeof(uint32_t));
if (m->chunk_large_offsets && offset32 & MIDX_LARGE_OFFSET_NEEDED) {
if (sizeof(off_t) < sizeof(uint64_t))
die(_("multi-pack-index stores a 64-bit offset, but off_t is too small"));
offset32 ^= MIDX_LARGE_OFFSET_NEEDED;
if (offset32 >= m->chunk_large_offsets_len / sizeof(uint64_t))
die(_("multi-pack-index large offset out of bounds"));
return get_be64(m->chunk_large_offsets + sizeof(uint64_t) * offset32);
}
return offset32;
}
uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos)
{
return get_be32(m->chunk_object_offsets +
(off_t)pos * MIDX_CHUNK_OFFSET_WIDTH);
}
int fill_midx_entry(struct repository *r,
const struct object_id *oid,
struct pack_entry *e,
struct multi_pack_index *m)
{
uint32_t pos;
uint32_t pack_int_id;
struct packed_git *p;
if (!bsearch_midx(oid, m, &pos))
return 0;
if (pos >= m->num_objects)
return 0;
pack_int_id = nth_midxed_pack_int_id(m, pos);
if (prepare_midx_pack(r, m, pack_int_id))
return 0;
p = m->packs[pack_int_id];
/*
* We are about to tell the caller where they can locate the
* requested object. We better make sure the packfile is
* still here and can be accessed before supplying that
* answer, as it may have been deleted since the MIDX was
* loaded!
*/
if (!is_pack_valid(p))
return 0;
if (oidset_size(&p->bad_objects) &&
oidset_contains(&p->bad_objects, oid))
return 0;
e->offset = nth_midxed_offset(m, pos);
e->p = p;
return 1;
}
/* Match "foo.idx" against either "foo.pack" _or_ "foo.idx". */
static int cmp_idx_or_pack_name(const char *idx_or_pack_name,
const char *idx_name)
{
/* Skip past any initial matching prefix. */
while (*idx_name && *idx_name == *idx_or_pack_name) {
idx_name++;
idx_or_pack_name++;
}
/*
* If we didn't match completely, we may have matched "pack-1234." and
* be left with "idx" and "pack" respectively, which is also OK. We do
* not have to check for "idx" and "idx", because that would have been
* a complete match (and in that case these strcmps will be false, but
* we'll correctly return 0 from the final strcmp() below.
*
* Technically this matches "fooidx" and "foopack", but we'd never have
* such names in the first place.
*/
if (!strcmp(idx_name, "idx") && !strcmp(idx_or_pack_name, "pack"))
return 0;
/*
* This not only checks for a complete match, but also orders based on
* the first non-identical character, which means our ordering will
* match a raw strcmp(). That makes it OK to use this to binary search
* a naively-sorted list.
*/
return strcmp(idx_or_pack_name, idx_name);
}
int midx_contains_pack(struct multi_pack_index *m, const char *idx_or_pack_name)
{
uint32_t first = 0, last = m->num_packs;
while (first < last) {
uint32_t mid = first + (last - first) / 2;
const char *current;
int cmp;
current = m->pack_names[mid];
cmp = cmp_idx_or_pack_name(idx_or_pack_name, current);
if (!cmp)
return 1;
if (cmp > 0) {
first = mid + 1;
continue;
}
last = mid;
}
return 0;
}
int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, int local)
{
struct multi_pack_index *m;
struct multi_pack_index *m_search;
prepare_repo_settings(r);
if (!r->settings.core_multi_pack_index)
return 0;
for (m_search = r->objects->multi_pack_index; m_search; m_search = m_search->next)
if (!strcmp(object_dir, m_search->object_dir))
return 1;
m = load_multi_pack_index(object_dir, local);
if (m) {
struct multi_pack_index *mp = r->objects->multi_pack_index;
if (mp) {
m->next = mp->next;
mp->next = m;
} else
r->objects->multi_pack_index = m;
return 1;
}
return 0;
}
static size_t write_midx_header(struct hashfile *f,
unsigned char num_chunks,
uint32_t num_packs)
{
hashwrite_be32(f, MIDX_SIGNATURE);
hashwrite_u8(f, MIDX_VERSION);
hashwrite_u8(f, oid_version(the_hash_algo));
hashwrite_u8(f, num_chunks);
hashwrite_u8(f, 0); /* unused */
hashwrite_be32(f, num_packs);
return MIDX_HEADER_SIZE;
}
struct pack_info {
uint32_t orig_pack_int_id;
char *pack_name;
struct packed_git *p;
unsigned expired : 1;
};
static int pack_info_compare(const void *_a, const void *_b)
{
struct pack_info *a = (struct pack_info *)_a;
struct pack_info *b = (struct pack_info *)_b;
return strcmp(a->pack_name, b->pack_name);
}
static int idx_or_pack_name_cmp(const void *_va, const void *_vb)
{
const char *pack_name = _va;
const struct pack_info *compar = _vb;
return cmp_idx_or_pack_name(pack_name, compar->pack_name);
}
struct write_midx_context {
struct pack_info *info;
size_t nr;
size_t alloc;
struct multi_pack_index *m;
struct progress *progress;
unsigned pack_paths_checked;
struct pack_midx_entry *entries;
size_t entries_nr;
uint32_t *pack_perm;
uint32_t *pack_order;
unsigned large_offsets_needed:1;
uint32_t num_large_offsets;
int preferred_pack_idx;
struct string_list *to_include;
};
static void add_pack_to_midx(const char *full_path, size_t full_path_len,
const char *file_name, void *data)
{
struct write_midx_context *ctx = data;
if (ends_with(file_name, ".idx")) {
display_progress(ctx->progress, ++ctx->pack_paths_checked);
/*
* Note that at most one of ctx->m and ctx->to_include are set,
* so we are testing midx_contains_pack() and
* string_list_has_string() independently (guarded by the
* appropriate NULL checks).
*
* We could support passing to_include while reusing an existing
* MIDX, but don't currently since the reuse process drags
* forward all packs from an existing MIDX (without checking
* whether or not they appear in the to_include list).
*
* If we added support for that, these next two conditional
* should be performed independently (likely checking
* to_include before the existing MIDX).
*/
if (ctx->m && midx_contains_pack(ctx->m, file_name))
return;
else if (ctx->to_include &&
!string_list_has_string(ctx->to_include, file_name))
return;
ALLOC_GROW(ctx->info, ctx->nr + 1, ctx->alloc);
ctx->info[ctx->nr].p = add_packed_git(full_path,
full_path_len,
0);
if (!ctx->info[ctx->nr].p) {
warning(_("failed to add packfile '%s'"),
full_path);
return;
}
if (open_pack_index(ctx->info[ctx->nr].p)) {
warning(_("failed to open pack-index '%s'"),
full_path);
close_pack(ctx->info[ctx->nr].p);
FREE_AND_NULL(ctx->info[ctx->nr].p);
return;
}
ctx->info[ctx->nr].pack_name = xstrdup(file_name);
ctx->info[ctx->nr].orig_pack_int_id = ctx->nr;
ctx->info[ctx->nr].expired = 0;
ctx->nr++;
}
}
struct pack_midx_entry {
struct object_id oid;
uint32_t pack_int_id;
time_t pack_mtime;
uint64_t offset;
unsigned preferred : 1;
};
static int midx_oid_compare(const void *_a, const void *_b)
{
const struct pack_midx_entry *a = (const struct pack_midx_entry *)_a;
const struct pack_midx_entry *b = (const struct pack_midx_entry *)_b;
int cmp = oidcmp(&a->oid, &b->oid);
if (cmp)
return cmp;
/* Sort objects in a preferred pack first when multiple copies exist. */
if (a->preferred > b->preferred)
return -1;
if (a->preferred < b->preferred)
return 1;
if (a->pack_mtime > b->pack_mtime)
return -1;
else if (a->pack_mtime < b->pack_mtime)
return 1;
return a->pack_int_id - b->pack_int_id;
}
static int nth_midxed_pack_midx_entry(struct multi_pack_index *m,
struct pack_midx_entry *e,
uint32_t pos)
{
if (pos >= m->num_objects)
return 1;
nth_midxed_object_oid(&e->oid, m, pos);
e->pack_int_id = nth_midxed_pack_int_id(m, pos);
e->offset = nth_midxed_offset(m, pos);
/* consider objects in midx to be from "old" packs */
e->pack_mtime = 0;
return 0;
}
static void fill_pack_entry(uint32_t pack_int_id,
struct packed_git *p,
uint32_t cur_object,
struct pack_midx_entry *entry,
int preferred)
{
if (nth_packed_object_id(&entry->oid, p, cur_object) < 0)
die(_("failed to locate object %d in packfile"), cur_object);
entry->pack_int_id = pack_int_id;
entry->pack_mtime = p->mtime;
entry->offset = nth_packed_object_offset(p, cur_object);
entry->preferred = !!preferred;
}
struct midx_fanout {
struct pack_midx_entry *entries;
size_t nr, alloc;
};
static void midx_fanout_grow(struct midx_fanout *fanout, size_t nr)
{
if (nr < fanout->nr)
BUG("negative growth in midx_fanout_grow() (%"PRIuMAX" < %"PRIuMAX")",
(uintmax_t)nr, (uintmax_t)fanout->nr);
ALLOC_GROW(fanout->entries, nr, fanout->alloc);
}
static void midx_fanout_sort(struct midx_fanout *fanout)
{
QSORT(fanout->entries, fanout->nr, midx_oid_compare);
}
static void midx_fanout_add_midx_fanout(struct midx_fanout *fanout,
struct multi_pack_index *m,
uint32_t cur_fanout,
int preferred_pack)
{
uint32_t start = 0, end;
uint32_t cur_object;
if (cur_fanout)
start = ntohl(m->chunk_oid_fanout[cur_fanout - 1]);
end = ntohl(m->chunk_oid_fanout[cur_fanout]);
for (cur_object = start; cur_object < end; cur_object++) {
if ((preferred_pack > -1) &&
(preferred_pack == nth_midxed_pack_int_id(m, cur_object))) {
/*
* Objects from preferred packs are added
* separately.
*/
continue;
}
midx_fanout_grow(fanout, fanout->nr + 1);
nth_midxed_pack_midx_entry(m,
&fanout->entries[fanout->nr],
cur_object);
fanout->entries[fanout->nr].preferred = 0;
fanout->nr++;
}
}
static void midx_fanout_add_pack_fanout(struct midx_fanout *fanout,
struct pack_info *info,
uint32_t cur_pack,
int preferred,
uint32_t cur_fanout)
{
struct packed_git *pack = info[cur_pack].p;
uint32_t start = 0, end;
uint32_t cur_object;
if (cur_fanout)
start = get_pack_fanout(pack, cur_fanout - 1);
end = get_pack_fanout(pack, cur_fanout);
for (cur_object = start; cur_object < end; cur_object++) {
midx_fanout_grow(fanout, fanout->nr + 1);
fill_pack_entry(cur_pack,
info[cur_pack].p,
cur_object,
&fanout->entries[fanout->nr],
preferred);
fanout->nr++;
}
}
/*
* It is possible to artificially get into a state where there are many
* duplicate copies of objects. That can create high memory pressure if
* we are to create a list of all objects before de-duplication. To reduce
* this memory pressure without a significant performance drop, automatically
* group objects by the first byte of their object id. Use the IDX fanout
* tables to group the data, copy to a local array, then sort.
*
* Copy only the de-duplicated entries (selected by most-recent modified time
* of a packfile containing the object).
*/
static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
struct pack_info *info,
uint32_t nr_packs,
size_t *nr_objects,
int preferred_pack)
{
uint32_t cur_fanout, cur_pack, cur_object;
size_t alloc_objects, total_objects = 0;
struct midx_fanout fanout = { 0 };
struct pack_midx_entry *deduplicated_entries = NULL;
uint32_t start_pack = m ? m->num_packs : 0;
for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++)
total_objects = st_add(total_objects,
info[cur_pack].p->num_objects);
/*
* As we de-duplicate by fanout value, we expect the fanout
* slices to be evenly distributed, with some noise. Hence,
* allocate slightly more than one 256th.
*/
alloc_objects = fanout.alloc = total_objects > 3200 ? total_objects / 200 : 16;
ALLOC_ARRAY(fanout.entries, fanout.alloc);
ALLOC_ARRAY(deduplicated_entries, alloc_objects);
*nr_objects = 0;
for (cur_fanout = 0; cur_fanout < 256; cur_fanout++) {
fanout.nr = 0;
if (m)
midx_fanout_add_midx_fanout(&fanout, m, cur_fanout,
preferred_pack);
for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++) {
int preferred = cur_pack == preferred_pack;
midx_fanout_add_pack_fanout(&fanout,
info, cur_pack,
preferred, cur_fanout);
}
if (-1 < preferred_pack && preferred_pack < start_pack)
midx_fanout_add_pack_fanout(&fanout, info,
preferred_pack, 1,
cur_fanout);
midx_fanout_sort(&fanout);
/*
* The batch is now sorted by OID and then mtime (descending).
* Take only the first duplicate.
*/
for (cur_object = 0; cur_object < fanout.nr; cur_object++) {
if (cur_object && oideq(&fanout.entries[cur_object - 1].oid,
&fanout.entries[cur_object].oid))
continue;
ALLOC_GROW(deduplicated_entries, st_add(*nr_objects, 1),
alloc_objects);
memcpy(&deduplicated_entries[*nr_objects],
&fanout.entries[cur_object],
sizeof(struct pack_midx_entry));
(*nr_objects)++;
}
}
free(fanout.entries);
return deduplicated_entries;
}
static int write_midx_pack_names(struct hashfile *f, void *data)
{
struct write_midx_context *ctx = data;
uint32_t i;
unsigned char padding[MIDX_CHUNK_ALIGNMENT];
size_t written = 0;
for (i = 0; i < ctx->nr; i++) {
size_t writelen;
if (ctx->info[i].expired)
continue;
if (i && strcmp(ctx->info[i].pack_name, ctx->info[i - 1].pack_name) <= 0)
BUG("incorrect pack-file order: %s before %s",
ctx->info[i - 1].pack_name,
ctx->info[i].pack_name);
writelen = strlen(ctx->info[i].pack_name) + 1;
hashwrite(f, ctx->info[i].pack_name, writelen);
written += writelen;
}
/* add padding to be aligned */
i = MIDX_CHUNK_ALIGNMENT - (written % MIDX_CHUNK_ALIGNMENT);
if (i < MIDX_CHUNK_ALIGNMENT) {
memset(padding, 0, sizeof(padding));
hashwrite(f, padding, i);
}
return 0;
}
static int write_midx_oid_fanout(struct hashfile *f,
void *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;
uint32_t i;
/*
* Write the first-level table (the list is sorted,
* but we use a 256-entry lookup to be able to avoid
* having to do eight extra binary search iterations).
*/
for (i = 0; i < 256; i++) {
struct pack_midx_entry *next = list;
while (next < last && next->oid.hash[0] == i) {
count++;
next++;
}
hashwrite_be32(f, count);
list = next;
}
return 0;
}
static int write_midx_oid_lookup(struct hashfile *f,
void *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;
for (i = 0; i < ctx->entries_nr; i++) {
struct pack_midx_entry *obj = list++;
if (i < ctx->entries_nr - 1) {
struct pack_midx_entry *next = list;
if (oidcmp(&obj->oid, &next->oid) >= 0)
BUG("OIDs not in order: %s >= %s",
oid_to_hex(&obj->oid),
oid_to_hex(&next->oid));
}
hashwrite(f, obj->oid.hash, (int)hash_len);
}
return 0;
}
static int write_midx_object_offsets(struct hashfile *f,
void *data)
{
struct write_midx_context *ctx = data;
struct pack_midx_entry *list = ctx->entries;
uint32_t i, nr_large_offset = 0;
for (i = 0; i < ctx->entries_nr; i++) {
struct pack_midx_entry *obj = list++;
if (ctx->pack_perm[obj->pack_int_id] == PACK_EXPIRED)
BUG("object %s is in an expired pack with int-id %d",
oid_to_hex(&obj->oid),
obj->pack_int_id);
hashwrite_be32(f, ctx->pack_perm[obj->pack_int_id]);
if (ctx->large_offsets_needed && obj->offset >> 31)
hashwrite_be32(f, MIDX_LARGE_OFFSET_NEEDED | nr_large_offset++);
else if (!ctx->large_offsets_needed && obj->offset >> 32)
BUG("object %s requires a large offset (%"PRIx64") but the MIDX is not writing large offsets!",
oid_to_hex(&obj->oid),
obj->offset);
else
hashwrite_be32(f, (uint32_t)obj->offset);
}
return 0;
}
static int write_midx_large_offsets(struct hashfile *f,
void *data)
{
struct write_midx_context *ctx = data;
struct pack_midx_entry *list = ctx->entries;
struct pack_midx_entry *end = ctx->entries + ctx->entries_nr;
uint32_t nr_large_offset = ctx->num_large_offsets;
while (nr_large_offset) {
struct pack_midx_entry *obj;
uint64_t offset;
if (list >= end)
BUG("too many large-offset objects");
obj = list++;
offset = obj->offset;
if (!(offset >> 31))
continue;
hashwrite_be64(f, offset);
nr_large_offset--;
}
return 0;
}
static int write_midx_revindex(struct hashfile *f,
void *data)
{
struct write_midx_context *ctx = data;
uint32_t i;
for (i = 0; i < ctx->entries_nr; i++)
hashwrite_be32(f, ctx->pack_order[i]);
return 0;
}
struct midx_pack_order_data {
uint32_t nr;
uint32_t pack;
off_t offset;
};
static int midx_pack_order_cmp(const void *va, const void *vb)
{
const struct midx_pack_order_data *a = va, *b = vb;
if (a->pack < b->pack)
return -1;
else if (a->pack > b->pack)
return 1;
else if (a->offset < b->offset)
return -1;
else if (a->offset > b->offset)
return 1;
else
return 0;
}
static uint32_t *midx_pack_order(struct write_midx_context *ctx)
{
struct midx_pack_order_data *data;
uint32_t *pack_order;
uint32_t i;
trace2_region_enter("midx", "midx_pack_order", the_repository);
ALLOC_ARRAY(data, ctx->entries_nr);
for (i = 0; i < ctx->entries_nr; i++) {
struct pack_midx_entry *e = &ctx->entries[i];
data[i].nr = i;
data[i].pack = ctx->pack_perm[e->pack_int_id];
if (!e->preferred)
data[i].pack |= (1U << 31);
data[i].offset = e->offset;
}
QSORT(data, ctx->entries_nr, midx_pack_order_cmp);
ALLOC_ARRAY(pack_order, ctx->entries_nr);
for (i = 0; i < ctx->entries_nr; i++)
pack_order[i] = data[i].nr;
free(data);
trace2_region_leave("midx", "midx_pack_order", the_repository);
return pack_order;
}
static void write_midx_reverse_index(char *midx_name, unsigned char *midx_hash,
struct write_midx_context *ctx)
{
struct strbuf buf = STRBUF_INIT;
const char *tmp_file;