tvl-depot/third_party/git/midx.c
Vincent Ambo f4609b896f merge(3p/git): Merge git subtree at v2.29.2
This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb
2020-11-21 19:45:56 +01:00

1487 lines
38 KiB
C

#include "cache.h"
#include "config.h"
#include "csum-file.h"
#include "dir.h"
#include "lockfile.h"
#include "packfile.h"
#include "object-store.h"
#include "sha1-lookup.h"
#include "midx.h"
#include "progress.h"
#include "trace2.h"
#include "run-command.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_MAX_CHUNKS 5
#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_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t))
#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
static uint8_t oid_version(void)
{
switch (hash_algo_by_ptr(the_hash_algo)) {
case GIT_HASH_SHA1:
return 1;
case GIT_HASH_SHA256:
return 2;
default:
die(_("invalid hash version"));
}
}
static char *get_midx_filename(const char *object_dir)
{
return xstrfmt("%s/pack/multi-pack-index", object_dir);
}
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;
char *midx_name = get_midx_filename(object_dir);
uint32_t i;
const char *cur_pack_name;
fd = git_open(midx_name);
if (fd < 0)
goto cleanup_fail;
if (fstat(fd, &st)) {
error_errno(_("failed to read %s"), midx_name);
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);
goto cleanup_fail;
}
FREE_AND_NULL(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()) {
error(_("multi-pack-index hash version %u does not match version %u"),
hash_version, oid_version());
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);
for (i = 0; i < m->num_chunks; i++) {
uint32_t chunk_id = get_be32(m->data + MIDX_HEADER_SIZE +
MIDX_CHUNKLOOKUP_WIDTH * i);
uint64_t chunk_offset = get_be64(m->data + MIDX_HEADER_SIZE + 4 +
MIDX_CHUNKLOOKUP_WIDTH * i);
if (chunk_offset >= m->data_len)
die(_("invalid chunk offset (too large)"));
switch (chunk_id) {
case MIDX_CHUNKID_PACKNAMES:
m->chunk_pack_names = m->data + chunk_offset;
break;
case MIDX_CHUNKID_OIDFANOUT:
m->chunk_oid_fanout = (uint32_t *)(m->data + chunk_offset);
break;
case MIDX_CHUNKID_OIDLOOKUP:
m->chunk_oid_lookup = m->data + chunk_offset;
break;
case MIDX_CHUNKID_OBJECTOFFSETS:
m->chunk_object_offsets = m->data + chunk_offset;
break;
case MIDX_CHUNKID_LARGEOFFSETS:
m->chunk_large_offsets = m->data + chunk_offset;
break;
case 0:
die(_("terminating multi-pack-index chunk id appears earlier than expected"));
break;
default:
/*
* Do nothing on unrecognized chunks, allowing future
* extensions to add optional chunks.
*/
break;
}
}
if (!m->chunk_pack_names)
die(_("multi-pack-index missing required pack-name chunk"));
if (!m->chunk_oid_fanout)
die(_("multi-pack-index missing required OID fanout chunk"));
if (!m->chunk_oid_lookup)
die(_("multi-pack-index missing required OID lookup chunk"));
if (!m->chunk_object_offsets)
die(_("multi-pack-index missing required object offsets chunk"));
m->num_objects = ntohl(m->chunk_oid_fanout[255]);
m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names));
m->packs = xcalloc(m->num_packs, sizeof(*m->packs));
cur_pack_name = (const char *)m->chunk_pack_names;
for (i = 0; i < m->num_packs; i++) {
m->pack_names[i] = cur_pack_name;
cur_pack_name += strlen(cur_pack_name) + 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);
return m;
cleanup_fail:
free(m);
free(midx_name);
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;
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);
}
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;
hashcpy(oid->hash, m->chunk_oid_lookup + m->hash_len * n);
return oid;
}
static 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 + 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;
return get_be64(m->chunk_large_offsets + sizeof(uint64_t) * offset32);
}
return offset32;
}
static uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos)
{
return get_be32(m->chunk_object_offsets + pos * MIDX_CHUNK_OFFSET_WIDTH);
}
static int nth_midxed_pack_entry(struct repository *r,
struct multi_pack_index *m,
struct pack_entry *e,
uint32_t pos)
{
uint32_t pack_int_id;
struct packed_git *p;
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))
die(_("error preparing packfile from multi-pack-index"));
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 (p->num_bad_objects) {
uint32_t i;
struct object_id oid;
nth_midxed_object_oid(&oid, m, pos);
for (i = 0; i < p->num_bad_objects; i++)
if (hasheq(oid.hash,
p->bad_object_sha1 + the_hash_algo->rawsz * i))
return 0;
}
e->offset = nth_midxed_offset(m, pos);
e->p = p;
return 1;
}
int fill_midx_entry(struct repository * r,
const struct object_id *oid,
struct pack_entry *e,
struct multi_pack_index *m)
{
uint32_t pos;
if (!bsearch_midx(oid, m, &pos))
return 0;
return nth_midxed_pack_entry(r, m, e, pos);
}
/* 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;
int config_value;
static int env_value = -1;
if (env_value < 0)
env_value = git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0);
if (!env_value &&
(repo_config_get_bool(r, "core.multipackindex", &config_value) ||
!config_value))
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());
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);
}
struct pack_list {
struct pack_info *info;
uint32_t nr;
uint32_t alloc;
struct multi_pack_index *m;
struct progress *progress;
unsigned pack_paths_checked;
};
static void add_pack_to_midx(const char *full_path, size_t full_path_len,
const char *file_name, void *data)
{
struct pack_list *packs = (struct pack_list *)data;
if (ends_with(file_name, ".idx")) {
display_progress(packs->progress, ++packs->pack_paths_checked);
if (packs->m && midx_contains_pack(packs->m, file_name))
return;
ALLOC_GROW(packs->info, packs->nr + 1, packs->alloc);
packs->info[packs->nr].p = add_packed_git(full_path,
full_path_len,
0);
if (!packs->info[packs->nr].p) {
warning(_("failed to add packfile '%s'"),
full_path);
return;
}
if (open_pack_index(packs->info[packs->nr].p)) {
warning(_("failed to open pack-index '%s'"),
full_path);
close_pack(packs->info[packs->nr].p);
FREE_AND_NULL(packs->info[packs->nr].p);
return;
}
packs->info[packs->nr].pack_name = xstrdup(file_name);
packs->info[packs->nr].orig_pack_int_id = packs->nr;
packs->info[packs->nr].expired = 0;
packs->nr++;
}
}
struct pack_midx_entry {
struct object_id oid;
uint32_t pack_int_id;
time_t pack_mtime;
uint64_t offset;
};
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;
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)
{
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);
}
/*
* 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,
uint32_t *nr_objects)
{
uint32_t cur_fanout, cur_pack, cur_object;
uint32_t alloc_fanout, alloc_objects, total_objects = 0;
struct pack_midx_entry *entries_by_fanout = NULL;
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 += 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 = alloc_fanout = total_objects > 3200 ? total_objects / 200 : 16;
ALLOC_ARRAY(entries_by_fanout, alloc_fanout);
ALLOC_ARRAY(deduplicated_entries, alloc_objects);
*nr_objects = 0;
for (cur_fanout = 0; cur_fanout < 256; cur_fanout++) {
uint32_t nr_fanout = 0;
if (m) {
uint32_t start = 0, end;
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++) {
ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout);
nth_midxed_pack_midx_entry(m,
&entries_by_fanout[nr_fanout],
cur_object);
nr_fanout++;
}
}
for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++) {
uint32_t start = 0, end;
if (cur_fanout)
start = get_pack_fanout(info[cur_pack].p, cur_fanout - 1);
end = get_pack_fanout(info[cur_pack].p, cur_fanout);
for (cur_object = start; cur_object < end; cur_object++) {
ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout);
fill_pack_entry(cur_pack, info[cur_pack].p, cur_object, &entries_by_fanout[nr_fanout]);
nr_fanout++;
}
}
QSORT(entries_by_fanout, nr_fanout, midx_oid_compare);
/*
* The batch is now sorted by OID and then mtime (descending).
* Take only the first duplicate.
*/
for (cur_object = 0; cur_object < nr_fanout; cur_object++) {
if (cur_object && oideq(&entries_by_fanout[cur_object - 1].oid,
&entries_by_fanout[cur_object].oid))
continue;
ALLOC_GROW(deduplicated_entries, *nr_objects + 1, alloc_objects);
memcpy(&deduplicated_entries[*nr_objects],
&entries_by_fanout[cur_object],
sizeof(struct pack_midx_entry));
(*nr_objects)++;
}
}
free(entries_by_fanout);
return deduplicated_entries;
}
static size_t write_midx_pack_names(struct hashfile *f,
struct pack_info *info,
uint32_t num_packs)
{
uint32_t i;
unsigned char padding[MIDX_CHUNK_ALIGNMENT];
size_t written = 0;
for (i = 0; i < num_packs; i++) {
size_t writelen;
if (info[i].expired)
continue;
if (i && strcmp(info[i].pack_name, info[i - 1].pack_name) <= 0)
BUG("incorrect pack-file order: %s before %s",
info[i - 1].pack_name,
info[i].pack_name);
writelen = strlen(info[i].pack_name) + 1;
hashwrite(f, 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);
written += i;
}
return written;
}
static size_t write_midx_oid_fanout(struct hashfile *f,
struct pack_midx_entry *objects,
uint32_t nr_objects)
{
struct pack_midx_entry *list = objects;
struct pack_midx_entry *last = objects + nr_objects;
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 MIDX_CHUNK_FANOUT_SIZE;
}
static size_t write_midx_oid_lookup(struct hashfile *f, unsigned char hash_len,
struct pack_midx_entry *objects,
uint32_t nr_objects)
{
struct pack_midx_entry *list = objects;
uint32_t i;
size_t written = 0;
for (i = 0; i < nr_objects; i++) {
struct pack_midx_entry *obj = list++;
if (i < nr_objects - 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);
written += hash_len;
}
return written;
}
static size_t write_midx_object_offsets(struct hashfile *f, int large_offset_needed,
uint32_t *perm,
struct pack_midx_entry *objects, uint32_t nr_objects)
{
struct pack_midx_entry *list = objects;
uint32_t i, nr_large_offset = 0;
size_t written = 0;
for (i = 0; i < nr_objects; i++) {
struct pack_midx_entry *obj = list++;
if (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, perm[obj->pack_int_id]);
if (large_offset_needed && obj->offset >> 31)
hashwrite_be32(f, MIDX_LARGE_OFFSET_NEEDED | nr_large_offset++);
else if (!large_offset_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);
written += MIDX_CHUNK_OFFSET_WIDTH;
}
return written;
}
static size_t write_midx_large_offsets(struct hashfile *f, uint32_t nr_large_offset,
struct pack_midx_entry *objects, uint32_t nr_objects)
{
struct pack_midx_entry *list = objects, *end = objects + nr_objects;
size_t written = 0;
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_be32(f, offset >> 32);
hashwrite_be32(f, offset & 0xffffffffUL);
written += 2 * sizeof(uint32_t);
nr_large_offset--;
}
return written;
}
static int write_midx_internal(const char *object_dir, struct multi_pack_index *m,
struct string_list *packs_to_drop, unsigned flags)
{
unsigned char cur_chunk, num_chunks = 0;
char *midx_name;
uint32_t i;
struct hashfile *f = NULL;
struct lock_file lk;
struct pack_list packs;
uint32_t *pack_perm = NULL;
uint64_t written = 0;
uint32_t chunk_ids[MIDX_MAX_CHUNKS + 1];
uint64_t chunk_offsets[MIDX_MAX_CHUNKS + 1];
uint32_t nr_entries, num_large_offsets = 0;
struct pack_midx_entry *entries = NULL;
struct progress *progress = NULL;
int large_offsets_needed = 0;
int pack_name_concat_len = 0;
int dropped_packs = 0;
int result = 0;
midx_name = get_midx_filename(object_dir);
if (safe_create_leading_directories(midx_name))
die_errno(_("unable to create leading directories of %s"),
midx_name);
if (m)
packs.m = m;
else
packs.m = load_multi_pack_index(object_dir, 1);
packs.nr = 0;
packs.alloc = packs.m ? packs.m->num_packs : 16;
packs.info = NULL;
ALLOC_ARRAY(packs.info, packs.alloc);
if (packs.m) {
for (i = 0; i < packs.m->num_packs; i++) {
ALLOC_GROW(packs.info, packs.nr + 1, packs.alloc);
packs.info[packs.nr].orig_pack_int_id = i;
packs.info[packs.nr].pack_name = xstrdup(packs.m->pack_names[i]);
packs.info[packs.nr].p = NULL;
packs.info[packs.nr].expired = 0;
packs.nr++;
}
}
packs.pack_paths_checked = 0;
if (flags & MIDX_PROGRESS)
packs.progress = start_progress(_("Adding packfiles to multi-pack-index"), 0);
else
packs.progress = NULL;
for_each_file_in_pack_dir(object_dir, add_pack_to_midx, &packs);
stop_progress(&packs.progress);
if (packs.m && packs.nr == packs.m->num_packs && !packs_to_drop)
goto cleanup;
entries = get_sorted_entries(packs.m, packs.info, packs.nr, &nr_entries);
for (i = 0; i < nr_entries; i++) {
if (entries[i].offset > 0x7fffffff)
num_large_offsets++;
if (entries[i].offset > 0xffffffff)
large_offsets_needed = 1;
}
QSORT(packs.info, packs.nr, pack_info_compare);
if (packs_to_drop && packs_to_drop->nr) {
int drop_index = 0;
int missing_drops = 0;
for (i = 0; i < packs.nr && drop_index < packs_to_drop->nr; i++) {
int cmp = strcmp(packs.info[i].pack_name,
packs_to_drop->items[drop_index].string);
if (!cmp) {
drop_index++;
packs.info[i].expired = 1;
} else if (cmp > 0) {
error(_("did not see pack-file %s to drop"),
packs_to_drop->items[drop_index].string);
drop_index++;
missing_drops++;
i--;
} else {
packs.info[i].expired = 0;
}
}
if (missing_drops) {
result = 1;
goto cleanup;
}
}
/*
* pack_perm stores a permutation between pack-int-ids from the
* previous multi-pack-index to the new one we are writing:
*
* pack_perm[old_id] = new_id
*/
ALLOC_ARRAY(pack_perm, packs.nr);
for (i = 0; i < packs.nr; i++) {
if (packs.info[i].expired) {
dropped_packs++;
pack_perm[packs.info[i].orig_pack_int_id] = PACK_EXPIRED;
} else {
pack_perm[packs.info[i].orig_pack_int_id] = i - dropped_packs;
}
}
for (i = 0; i < packs.nr; i++) {
if (!packs.info[i].expired)
pack_name_concat_len += strlen(packs.info[i].pack_name) + 1;
}
if (pack_name_concat_len % MIDX_CHUNK_ALIGNMENT)
pack_name_concat_len += MIDX_CHUNK_ALIGNMENT -
(pack_name_concat_len % MIDX_CHUNK_ALIGNMENT);
hold_lock_file_for_update(&lk, midx_name, LOCK_DIE_ON_ERROR);
f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
FREE_AND_NULL(midx_name);
if (packs.m)
close_midx(packs.m);
cur_chunk = 0;
num_chunks = large_offsets_needed ? 5 : 4;
if (packs.nr - dropped_packs == 0) {
error(_("no pack files to index."));
result = 1;
goto cleanup;
}
written = write_midx_header(f, num_chunks, packs.nr - dropped_packs);
chunk_ids[cur_chunk] = MIDX_CHUNKID_PACKNAMES;
chunk_offsets[cur_chunk] = written + (num_chunks + 1) * MIDX_CHUNKLOOKUP_WIDTH;
cur_chunk++;
chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDFANOUT;
chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + pack_name_concat_len;
cur_chunk++;
chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDLOOKUP;
chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + MIDX_CHUNK_FANOUT_SIZE;
cur_chunk++;
chunk_ids[cur_chunk] = MIDX_CHUNKID_OBJECTOFFSETS;
chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + nr_entries * the_hash_algo->rawsz;
cur_chunk++;
chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + nr_entries * MIDX_CHUNK_OFFSET_WIDTH;
if (large_offsets_needed) {
chunk_ids[cur_chunk] = MIDX_CHUNKID_LARGEOFFSETS;
cur_chunk++;
chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] +
num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH;
}
chunk_ids[cur_chunk] = 0;
for (i = 0; i <= num_chunks; i++) {
if (i && chunk_offsets[i] < chunk_offsets[i - 1])
BUG("incorrect chunk offsets: %"PRIu64" before %"PRIu64,
chunk_offsets[i - 1],
chunk_offsets[i]);
if (chunk_offsets[i] % MIDX_CHUNK_ALIGNMENT)
BUG("chunk offset %"PRIu64" is not properly aligned",
chunk_offsets[i]);
hashwrite_be32(f, chunk_ids[i]);
hashwrite_be32(f, chunk_offsets[i] >> 32);
hashwrite_be32(f, chunk_offsets[i]);
written += MIDX_CHUNKLOOKUP_WIDTH;
}
if (flags & MIDX_PROGRESS)
progress = start_progress(_("Writing chunks to multi-pack-index"),
num_chunks);
for (i = 0; i < num_chunks; i++) {
if (written != chunk_offsets[i])
BUG("incorrect chunk offset (%"PRIu64" != %"PRIu64") for chunk id %"PRIx32,
chunk_offsets[i],
written,
chunk_ids[i]);
switch (chunk_ids[i]) {
case MIDX_CHUNKID_PACKNAMES:
written += write_midx_pack_names(f, packs.info, packs.nr);
break;
case MIDX_CHUNKID_OIDFANOUT:
written += write_midx_oid_fanout(f, entries, nr_entries);
break;
case MIDX_CHUNKID_OIDLOOKUP:
written += write_midx_oid_lookup(f, the_hash_algo->rawsz, entries, nr_entries);
break;
case MIDX_CHUNKID_OBJECTOFFSETS:
written += write_midx_object_offsets(f, large_offsets_needed, pack_perm, entries, nr_entries);
break;
case MIDX_CHUNKID_LARGEOFFSETS:
written += write_midx_large_offsets(f, num_large_offsets, entries, nr_entries);
break;
default:
BUG("trying to write unknown chunk id %"PRIx32,
chunk_ids[i]);
}
display_progress(progress, i + 1);
}
stop_progress(&progress);
if (written != chunk_offsets[num_chunks])
BUG("incorrect final offset %"PRIu64" != %"PRIu64,
written,
chunk_offsets[num_chunks]);
finalize_hashfile(f, NULL, CSUM_FSYNC | CSUM_HASH_IN_STREAM);
commit_lock_file(&lk);
cleanup:
for (i = 0; i < packs.nr; i++) {
if (packs.info[i].p) {
close_pack(packs.info[i].p);
free(packs.info[i].p);
}
free(packs.info[i].pack_name);
}
free(packs.info);
free(entries);
free(pack_perm);
free(midx_name);
return result;
}
int write_midx_file(const char *object_dir, unsigned flags)
{
return write_midx_internal(object_dir, NULL, NULL, flags);
}
void clear_midx_file(struct repository *r)
{
char *midx = get_midx_filename(r->objects->odb->path);
if (r->objects && r->objects->multi_pack_index) {
close_midx(r->objects->multi_pack_index);
r->objects->multi_pack_index = NULL;
}
if (remove_path(midx))
die(_("failed to clear multi-pack-index at %s"), midx);
free(midx);
}
static int verify_midx_error;
static void midx_report(const char *fmt, ...)
{
va_list ap;
verify_midx_error = 1;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
va_end(ap);
}
struct pair_pos_vs_id
{
uint32_t pos;
uint32_t pack_int_id;
};
static int compare_pair_pos_vs_id(const void *_a, const void *_b)
{
struct pair_pos_vs_id *a = (struct pair_pos_vs_id *)_a;
struct pair_pos_vs_id *b = (struct pair_pos_vs_id *)_b;
return b->pack_int_id - a->pack_int_id;
}
/*
* Limit calls to display_progress() for performance reasons.
* The interval here was arbitrarily chosen.
*/
#define SPARSE_PROGRESS_INTERVAL (1 << 12)
#define midx_display_sparse_progress(progress, n) \
do { \
uint64_t _n = (n); \
if ((_n & (SPARSE_PROGRESS_INTERVAL - 1)) == 0) \
display_progress(progress, _n); \
} while (0)
int verify_midx_file(struct repository *r, const char *object_dir, unsigned flags)
{
struct pair_pos_vs_id *pairs = NULL;
uint32_t i;
struct progress *progress = NULL;
struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
verify_midx_error = 0;
if (!m) {
int result = 0;
struct stat sb;
char *filename = get_midx_filename(object_dir);
if (!stat(filename, &sb)) {
error(_("multi-pack-index file exists, but failed to parse"));
result = 1;
}
free(filename);
return result;
}
if (flags & MIDX_PROGRESS)
progress = start_progress(_("Looking for referenced packfiles"),
m->num_packs);
for (i = 0; i < m->num_packs; i++) {
if (prepare_midx_pack(r, m, i))
midx_report("failed to load pack in position %d", i);
display_progress(progress, i + 1);
}
stop_progress(&progress);
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)
midx_report(_("oid fanout out of order: fanout[%d] = %"PRIx32" > %"PRIx32" = fanout[%d]"),
i, oid_fanout1, oid_fanout2, i + 1);
}
if (m->num_objects == 0) {
midx_report(_("the midx contains no oid"));
/*
* Remaining tests assume that we have objects, so we can
* return here.
*/
return verify_midx_error;
}
if (flags & MIDX_PROGRESS)
progress = start_sparse_progress(_("Verifying OID order in multi-pack-index"),
m->num_objects - 1);
for (i = 0; i < m->num_objects - 1; i++) {
struct object_id oid1, oid2;
nth_midxed_object_oid(&oid1, m, i);
nth_midxed_object_oid(&oid2, m, i + 1);
if (oidcmp(&oid1, &oid2) >= 0)
midx_report(_("oid lookup out of order: oid[%d] = %s >= %s = oid[%d]"),
i, oid_to_hex(&oid1), oid_to_hex(&oid2), i + 1);
midx_display_sparse_progress(progress, i + 1);
}
stop_progress(&progress);
/*
* Create an array mapping each object to its packfile id. Sort it
* to group the objects by packfile. Use this permutation to visit
* each of the objects and only require 1 packfile to be open at a
* time.
*/
ALLOC_ARRAY(pairs, m->num_objects);
for (i = 0; i < m->num_objects; i++) {
pairs[i].pos = i;
pairs[i].pack_int_id = nth_midxed_pack_int_id(m, i);
}
if (flags & MIDX_PROGRESS)
progress = start_sparse_progress(_("Sorting objects by packfile"),
m->num_objects);
display_progress(progress, 0); /* TODO: Measure QSORT() progress */
QSORT(pairs, m->num_objects, compare_pair_pos_vs_id);
stop_progress(&progress);
if (flags & MIDX_PROGRESS)
progress = start_sparse_progress(_("Verifying object offsets"), m->num_objects);
for (i = 0; i < m->num_objects; i++) {
struct object_id oid;
struct pack_entry e;
off_t m_offset, p_offset;
if (i > 0 && pairs[i-1].pack_int_id != pairs[i].pack_int_id &&
m->packs[pairs[i-1].pack_int_id])
{
close_pack_fd(m->packs[pairs[i-1].pack_int_id]);
close_pack_index(m->packs[pairs[i-1].pack_int_id]);
}
nth_midxed_object_oid(&oid, m, pairs[i].pos);
if (!fill_midx_entry(r, &oid, &e, m)) {
midx_report(_("failed to load pack entry for oid[%d] = %s"),
pairs[i].pos, oid_to_hex(&oid));
continue;
}
if (open_pack_index(e.p)) {
midx_report(_("failed to load pack-index for packfile %s"),
e.p->pack_name);
break;
}
m_offset = e.offset;
p_offset = find_pack_entry_one(oid.hash, e.p);
if (m_offset != p_offset)
midx_report(_("incorrect object offset for oid[%d] = %s: %"PRIx64" != %"PRIx64),
pairs[i].pos, oid_to_hex(&oid), m_offset, p_offset);
midx_display_sparse_progress(progress, i + 1);
}
stop_progress(&progress);
free(pairs);
return verify_midx_error;
}
int expire_midx_packs(struct repository *r, const char *object_dir, unsigned flags)
{
uint32_t i, *count, result = 0;
struct string_list packs_to_drop = STRING_LIST_INIT_DUP;
struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
struct progress *progress = NULL;
if (!m)
return 0;
count = xcalloc(m->num_packs, sizeof(uint32_t));
if (flags & MIDX_PROGRESS)
progress = start_progress(_("Counting referenced objects"),
m->num_objects);
for (i = 0; i < m->num_objects; i++) {
int pack_int_id = nth_midxed_pack_int_id(m, i);
count[pack_int_id]++;
display_progress(progress, i + 1);
}
stop_progress(&progress);
if (flags & MIDX_PROGRESS)
progress = start_progress(_("Finding and deleting unreferenced packfiles"),
m->num_packs);
for (i = 0; i < m->num_packs; i++) {
char *pack_name;
display_progress(progress, i + 1);
if (count[i])
continue;
if (prepare_midx_pack(r, m, i))
continue;
if (m->packs[i]->pack_keep)
continue;
pack_name = xstrdup(m->packs[i]->pack_name);
close_pack(m->packs[i]);
string_list_insert(&packs_to_drop, m->pack_names[i]);
unlink_pack_path(pack_name, 0);
free(pack_name);
}
stop_progress(&progress);
free(count);
if (packs_to_drop.nr)
result = write_midx_internal(object_dir, m, &packs_to_drop, flags);
string_list_clear(&packs_to_drop, 0);
return result;
}
struct repack_info {
timestamp_t mtime;
uint32_t referenced_objects;
uint32_t pack_int_id;
};
static int compare_by_mtime(const void *a_, const void *b_)
{
const struct repack_info *a, *b;
a = (const struct repack_info *)a_;
b = (const struct repack_info *)b_;
if (a->mtime < b->mtime)
return -1;
if (a->mtime > b->mtime)
return 1;
return 0;
}
static int fill_included_packs_all(struct repository *r,
struct multi_pack_index *m,
unsigned char *include_pack)
{
uint32_t i, count = 0;
int pack_kept_objects = 0;
repo_config_get_bool(r, "repack.packkeptobjects", &pack_kept_objects);
for (i = 0; i < m->num_packs; i++) {
if (prepare_midx_pack(r, m, i))
continue;
if (!pack_kept_objects && m->packs[i]->pack_keep)
continue;
include_pack[i] = 1;
count++;
}
return count < 2;
}
static int fill_included_packs_batch(struct repository *r,
struct multi_pack_index *m,
unsigned char *include_pack,
size_t batch_size)
{
uint32_t i, packs_to_repack;
size_t total_size;
struct repack_info *pack_info = xcalloc(m->num_packs, sizeof(struct repack_info));
int pack_kept_objects = 0;
repo_config_get_bool(r, "repack.packkeptobjects", &pack_kept_objects);
for (i = 0; i < m->num_packs; i++) {
pack_info[i].pack_int_id = i;
if (prepare_midx_pack(r, m, i))
continue;
pack_info[i].mtime = m->packs[i]->mtime;
}
for (i = 0; batch_size && i < m->num_objects; i++) {
uint32_t pack_int_id = nth_midxed_pack_int_id(m, i);
pack_info[pack_int_id].referenced_objects++;
}
QSORT(pack_info, m->num_packs, compare_by_mtime);
total_size = 0;
packs_to_repack = 0;
for (i = 0; total_size < batch_size && i < m->num_packs; i++) {
int pack_int_id = pack_info[i].pack_int_id;
struct packed_git *p = m->packs[pack_int_id];
size_t expected_size;
if (!p)
continue;
if (!pack_kept_objects && p->pack_keep)
continue;
if (open_pack_index(p) || !p->num_objects)
continue;
expected_size = (size_t)(p->pack_size
* pack_info[i].referenced_objects);
expected_size /= p->num_objects;
if (expected_size >= batch_size)
continue;
packs_to_repack++;
total_size += expected_size;
include_pack[pack_int_id] = 1;
}
free(pack_info);
if (packs_to_repack < 2)
return 1;
return 0;
}
int midx_repack(struct repository *r, const char *object_dir, size_t batch_size, unsigned flags)
{
int result = 0;
uint32_t i;
unsigned char *include_pack;
struct child_process cmd = CHILD_PROCESS_INIT;
FILE *cmd_in;
struct strbuf base_name = STRBUF_INIT;
struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
/*
* When updating the default for these configuration
* variables in builtin/repack.c, these must be adjusted
* to match.
*/
int delta_base_offset = 1;
int use_delta_islands = 0;
if (!m)
return 0;
include_pack = xcalloc(m->num_packs, sizeof(unsigned char));
if (batch_size) {
if (fill_included_packs_batch(r, m, include_pack, batch_size))
goto cleanup;
} else if (fill_included_packs_all(r, m, include_pack))
goto cleanup;
repo_config_get_bool(r, "repack.usedeltabaseoffset", &delta_base_offset);
repo_config_get_bool(r, "repack.usedeltaislands", &use_delta_islands);
strvec_push(&cmd.args, "pack-objects");
strbuf_addstr(&base_name, object_dir);
strbuf_addstr(&base_name, "/pack/pack");
strvec_push(&cmd.args, base_name.buf);
if (delta_base_offset)
strvec_push(&cmd.args, "--delta-base-offset");
if (use_delta_islands)
strvec_push(&cmd.args, "--delta-islands");
if (flags & MIDX_PROGRESS)
strvec_push(&cmd.args, "--progress");
else
strvec_push(&cmd.args, "-q");
strbuf_release(&base_name);
cmd.git_cmd = 1;
cmd.in = cmd.out = -1;
if (start_command(&cmd)) {
error(_("could not start pack-objects"));
result = 1;
goto cleanup;
}
cmd_in = xfdopen(cmd.in, "w");
for (i = 0; i < m->num_objects; i++) {
struct object_id oid;
uint32_t pack_int_id = nth_midxed_pack_int_id(m, i);
if (!include_pack[pack_int_id])
continue;
nth_midxed_object_oid(&oid, m, i);
fprintf(cmd_in, "%s\n", oid_to_hex(&oid));
}
fclose(cmd_in);
if (finish_command(&cmd)) {
error(_("could not finish pack-objects"));
result = 1;
goto cleanup;
}
result = write_midx_internal(object_dir, m, NULL, flags);
m = NULL;
cleanup:
if (m)
close_midx(m);
free(include_pack);
return result;
}