git/pack-bitmap.c
Junio C Hamano d0732a8120 Merge branch 'jk/unused-post-2.39-part2'
More work towards -Wunused.

* jk/unused-post-2.39-part2: (21 commits)
  help: mark unused parameter in git_unknown_cmd_config()
  run_processes_parallel: mark unused callback parameters
  userformat_want_item(): mark unused parameter
  for_each_commit_graft(): mark unused callback parameter
  rewrite_parents(): mark unused callback parameter
  fetch-pack: mark unused parameter in callback function
  notes: mark unused callback parameters
  prio-queue: mark unused parameters in comparison functions
  for_each_object: mark unused callback parameters
  list-objects: mark unused callback parameters
  mark unused parameters in signal handlers
  run-command: mark error routine parameters as unused
  mark "pointless" data pointers in callbacks
  ref-filter: mark unused callback parameters
  http-backend: mark unused parameters in virtual functions
  http-backend: mark argc/argv unused
  object-name: mark unused parameters in disambiguate callbacks
  serve: mark unused parameters in virtual functions
  serve: use repository pointer to get config
  ls-refs: drop config caching
  ...
2023-03-17 14:03:09 -07:00

2339 lines
60 KiB
C

#include "git-compat-util.h"
#include "alloc.h"
#include "commit.h"
#include "hex.h"
#include "strbuf.h"
#include "tag.h"
#include "diff.h"
#include "revision.h"
#include "progress.h"
#include "list-objects.h"
#include "pack.h"
#include "pack-bitmap.h"
#include "pack-revindex.h"
#include "pack-objects.h"
#include "packfile.h"
#include "repository.h"
#include "object-store.h"
#include "list-objects-filter-options.h"
#include "midx.h"
#include "config.h"
/*
* An entry on the bitmap index, representing the bitmap for a given
* commit.
*/
struct stored_bitmap {
struct object_id oid;
struct ewah_bitmap *root;
struct stored_bitmap *xor;
int flags;
};
/*
* The active bitmap index for a repository. By design, repositories only have
* a single bitmap index available (the index for the biggest packfile in
* the repository), since bitmap indexes need full closure.
*
* If there is more than one bitmap index available (e.g. because of alternates),
* the active bitmap index is the largest one.
*/
struct bitmap_index {
/*
* The pack or multi-pack index (MIDX) that this bitmap index belongs
* to.
*
* Exactly one of these must be non-NULL; this specifies the object
* order used to interpret this bitmap.
*/
struct packed_git *pack;
struct multi_pack_index *midx;
/*
* Mark the first `reuse_objects` in the packfile as reused:
* they will be sent as-is without using them for repacking
* calculations
*/
uint32_t reuse_objects;
/* mmapped buffer of the whole bitmap index */
unsigned char *map;
size_t map_size; /* size of the mmaped buffer */
size_t map_pos; /* current position when loading the index */
/*
* Type indexes.
*
* Each bitmap marks which objects in the packfile are of the given
* type. This provides type information when yielding the objects from
* the packfile during a walk, which allows for better delta bases.
*/
struct ewah_bitmap *commits;
struct ewah_bitmap *trees;
struct ewah_bitmap *blobs;
struct ewah_bitmap *tags;
/* Map from object ID -> `stored_bitmap` for all the bitmapped commits */
kh_oid_map_t *bitmaps;
/* Number of bitmapped commits */
uint32_t entry_count;
/* If not NULL, this is a name-hash cache pointing into map. */
uint32_t *hashes;
/* The checksum of the packfile or MIDX; points into map. */
const unsigned char *checksum;
/*
* If not NULL, this point into the commit table extension
* (within the memory mapped region `map`).
*/
unsigned char *table_lookup;
/*
* Extended index.
*
* When trying to perform bitmap operations with objects that are not
* packed in `pack`, these objects are added to this "fake index" and
* are assumed to appear at the end of the packfile for all operations
*/
struct eindex {
struct object **objects;
uint32_t *hashes;
uint32_t count, alloc;
kh_oid_pos_t *positions;
} ext_index;
/* Bitmap result of the last performed walk */
struct bitmap *result;
/* "have" bitmap from the last performed walk */
struct bitmap *haves;
/* Version of the bitmap index */
unsigned int version;
};
static struct ewah_bitmap *lookup_stored_bitmap(struct stored_bitmap *st)
{
struct ewah_bitmap *parent;
struct ewah_bitmap *composed;
if (!st->xor)
return st->root;
composed = ewah_pool_new();
parent = lookup_stored_bitmap(st->xor);
ewah_xor(st->root, parent, composed);
ewah_pool_free(st->root);
st->root = composed;
st->xor = NULL;
return composed;
}
/*
* Read a bitmap from the current read position on the mmaped
* index, and increase the read position accordingly
*/
static struct ewah_bitmap *read_bitmap_1(struct bitmap_index *index)
{
struct ewah_bitmap *b = ewah_pool_new();
ssize_t bitmap_size = ewah_read_mmap(b,
index->map + index->map_pos,
index->map_size - index->map_pos);
if (bitmap_size < 0) {
error(_("failed to load bitmap index (corrupted?)"));
ewah_pool_free(b);
return NULL;
}
index->map_pos += bitmap_size;
return b;
}
static uint32_t bitmap_num_objects(struct bitmap_index *index)
{
if (index->midx)
return index->midx->num_objects;
return index->pack->num_objects;
}
static int load_bitmap_header(struct bitmap_index *index)
{
struct bitmap_disk_header *header = (void *)index->map;
size_t header_size = sizeof(*header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz;
if (index->map_size < header_size + the_hash_algo->rawsz)
return error(_("corrupted bitmap index (too small)"));
if (memcmp(header->magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE)) != 0)
return error(_("corrupted bitmap index file (wrong header)"));
index->version = ntohs(header->version);
if (index->version != 1)
return error(_("unsupported version '%d' for bitmap index file"), index->version);
/* Parse known bitmap format options */
{
uint32_t flags = ntohs(header->options);
size_t cache_size = st_mult(bitmap_num_objects(index), sizeof(uint32_t));
unsigned char *index_end = index->map + index->map_size - the_hash_algo->rawsz;
if ((flags & BITMAP_OPT_FULL_DAG) == 0)
BUG("unsupported options for bitmap index file "
"(Git requires BITMAP_OPT_FULL_DAG)");
if (flags & BITMAP_OPT_HASH_CACHE) {
if (cache_size > index_end - index->map - header_size)
return error(_("corrupted bitmap index file (too short to fit hash cache)"));
index->hashes = (void *)(index_end - cache_size);
index_end -= cache_size;
}
if (flags & BITMAP_OPT_LOOKUP_TABLE) {
size_t table_size = st_mult(ntohl(header->entry_count),
BITMAP_LOOKUP_TABLE_TRIPLET_WIDTH);
if (table_size > index_end - index->map - header_size)
return error(_("corrupted bitmap index file (too short to fit lookup table)"));
if (git_env_bool("GIT_TEST_READ_COMMIT_TABLE", 1))
index->table_lookup = (void *)(index_end - table_size);
index_end -= table_size;
}
}
index->entry_count = ntohl(header->entry_count);
index->checksum = header->checksum;
index->map_pos += header_size;
return 0;
}
static struct stored_bitmap *store_bitmap(struct bitmap_index *index,
struct ewah_bitmap *root,
const struct object_id *oid,
struct stored_bitmap *xor_with,
int flags)
{
struct stored_bitmap *stored;
khiter_t hash_pos;
int ret;
stored = xmalloc(sizeof(struct stored_bitmap));
stored->root = root;
stored->xor = xor_with;
stored->flags = flags;
oidcpy(&stored->oid, oid);
hash_pos = kh_put_oid_map(index->bitmaps, stored->oid, &ret);
/*
* A 0 return code means the insertion succeeded with no changes,
* because the SHA1 already existed on the map. This is bad, there
* shouldn't be duplicated commits in the index.
*/
if (ret == 0) {
error(_("duplicate entry in bitmap index: '%s'"), oid_to_hex(oid));
return NULL;
}
kh_value(index->bitmaps, hash_pos) = stored;
return stored;
}
static inline uint32_t read_be32(const unsigned char *buffer, size_t *pos)
{
uint32_t result = get_be32(buffer + *pos);
(*pos) += sizeof(result);
return result;
}
static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos)
{
return buffer[(*pos)++];
}
#define MAX_XOR_OFFSET 160
static int nth_bitmap_object_oid(struct bitmap_index *index,
struct object_id *oid,
uint32_t n)
{
if (index->midx)
return nth_midxed_object_oid(oid, index->midx, n) ? 0 : -1;
return nth_packed_object_id(oid, index->pack, n);
}
static int load_bitmap_entries_v1(struct bitmap_index *index)
{
uint32_t i;
struct stored_bitmap *recent_bitmaps[MAX_XOR_OFFSET] = { NULL };
for (i = 0; i < index->entry_count; ++i) {
int xor_offset, flags;
struct ewah_bitmap *bitmap = NULL;
struct stored_bitmap *xor_bitmap = NULL;
uint32_t commit_idx_pos;
struct object_id oid;
if (index->map_size - index->map_pos < 6)
return error(_("corrupt ewah bitmap: truncated header for entry %d"), i);
commit_idx_pos = read_be32(index->map, &index->map_pos);
xor_offset = read_u8(index->map, &index->map_pos);
flags = read_u8(index->map, &index->map_pos);
if (nth_bitmap_object_oid(index, &oid, commit_idx_pos) < 0)
return error(_("corrupt ewah bitmap: commit index %u out of range"),
(unsigned)commit_idx_pos);
bitmap = read_bitmap_1(index);
if (!bitmap)
return -1;
if (xor_offset > MAX_XOR_OFFSET || xor_offset > i)
return error(_("corrupted bitmap pack index"));
if (xor_offset > 0) {
xor_bitmap = recent_bitmaps[(i - xor_offset) % MAX_XOR_OFFSET];
if (!xor_bitmap)
return error(_("invalid XOR offset in bitmap pack index"));
}
recent_bitmaps[i % MAX_XOR_OFFSET] = store_bitmap(
index, bitmap, &oid, xor_bitmap, flags);
}
return 0;
}
char *midx_bitmap_filename(struct multi_pack_index *midx)
{
struct strbuf buf = STRBUF_INIT;
get_midx_filename(&buf, midx->object_dir);
strbuf_addf(&buf, "-%s.bitmap", hash_to_hex(get_midx_checksum(midx)));
return strbuf_detach(&buf, NULL);
}
char *pack_bitmap_filename(struct packed_git *p)
{
size_t len;
if (!strip_suffix(p->pack_name, ".pack", &len))
BUG("pack_name does not end in .pack");
return xstrfmt("%.*s.bitmap", (int)len, p->pack_name);
}
static int open_midx_bitmap_1(struct bitmap_index *bitmap_git,
struct multi_pack_index *midx)
{
struct stat st;
char *bitmap_name = midx_bitmap_filename(midx);
int fd = git_open(bitmap_name);
uint32_t i;
struct packed_git *preferred;
if (fd < 0) {
if (errno != ENOENT)
warning_errno("cannot open '%s'", bitmap_name);
free(bitmap_name);
return -1;
}
free(bitmap_name);
if (fstat(fd, &st)) {
error_errno(_("cannot fstat bitmap file"));
close(fd);
return -1;
}
if (bitmap_git->pack || bitmap_git->midx) {
struct strbuf buf = STRBUF_INIT;
get_midx_filename(&buf, midx->object_dir);
trace2_data_string("bitmap", the_repository,
"ignoring extra midx bitmap file", buf.buf);
close(fd);
strbuf_release(&buf);
return -1;
}
bitmap_git->midx = midx;
bitmap_git->map_size = xsize_t(st.st_size);
bitmap_git->map_pos = 0;
bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ,
MAP_PRIVATE, fd, 0);
close(fd);
if (load_bitmap_header(bitmap_git) < 0)
goto cleanup;
if (!hasheq(get_midx_checksum(bitmap_git->midx), bitmap_git->checksum)) {
error(_("checksum doesn't match in MIDX and bitmap"));
goto cleanup;
}
if (load_midx_revindex(bitmap_git->midx) < 0) {
warning(_("multi-pack bitmap is missing required reverse index"));
goto cleanup;
}
for (i = 0; i < bitmap_git->midx->num_packs; i++) {
if (prepare_midx_pack(the_repository, bitmap_git->midx, i))
die(_("could not open pack %s"),
bitmap_git->midx->pack_names[i]);
}
preferred = bitmap_git->midx->packs[midx_preferred_pack(bitmap_git)];
if (!is_pack_valid(preferred)) {
warning(_("preferred pack (%s) is invalid"),
preferred->pack_name);
goto cleanup;
}
return 0;
cleanup:
munmap(bitmap_git->map, bitmap_git->map_size);
bitmap_git->map_size = 0;
bitmap_git->map_pos = 0;
bitmap_git->map = NULL;
bitmap_git->midx = NULL;
return -1;
}
static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git *packfile)
{
int fd;
struct stat st;
char *bitmap_name;
bitmap_name = pack_bitmap_filename(packfile);
fd = git_open(bitmap_name);
if (fd < 0) {
if (errno != ENOENT)
warning_errno("cannot open '%s'", bitmap_name);
free(bitmap_name);
return -1;
}
free(bitmap_name);
if (fstat(fd, &st)) {
error_errno(_("cannot fstat bitmap file"));
close(fd);
return -1;
}
if (bitmap_git->pack || bitmap_git->midx) {
trace2_data_string("bitmap", the_repository,
"ignoring extra bitmap file", packfile->pack_name);
close(fd);
return -1;
}
if (!is_pack_valid(packfile)) {
close(fd);
return -1;
}
bitmap_git->pack = packfile;
bitmap_git->map_size = xsize_t(st.st_size);
bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ, MAP_PRIVATE, fd, 0);
bitmap_git->map_pos = 0;
close(fd);
if (load_bitmap_header(bitmap_git) < 0) {
munmap(bitmap_git->map, bitmap_git->map_size);
bitmap_git->map = NULL;
bitmap_git->map_size = 0;
bitmap_git->map_pos = 0;
bitmap_git->pack = NULL;
return -1;
}
trace2_data_string("bitmap", the_repository, "opened bitmap file",
packfile->pack_name);
return 0;
}
static int load_reverse_index(struct bitmap_index *bitmap_git)
{
if (bitmap_is_midx(bitmap_git)) {
uint32_t i;
int ret;
/*
* The multi-pack-index's .rev file is already loaded via
* open_pack_bitmap_1().
*
* But we still need to open the individual pack .rev files,
* since we will need to make use of them in pack-objects.
*/
for (i = 0; i < bitmap_git->midx->num_packs; i++) {
ret = load_pack_revindex(bitmap_git->midx->packs[i]);
if (ret)
return ret;
}
return 0;
}
return load_pack_revindex(bitmap_git->pack);
}
static int load_bitmap(struct bitmap_index *bitmap_git)
{
assert(bitmap_git->map);
bitmap_git->bitmaps = kh_init_oid_map();
bitmap_git->ext_index.positions = kh_init_oid_pos();
if (load_reverse_index(bitmap_git))
goto failed;
if (!(bitmap_git->commits = read_bitmap_1(bitmap_git)) ||
!(bitmap_git->trees = read_bitmap_1(bitmap_git)) ||
!(bitmap_git->blobs = read_bitmap_1(bitmap_git)) ||
!(bitmap_git->tags = read_bitmap_1(bitmap_git)))
goto failed;
if (!bitmap_git->table_lookup && load_bitmap_entries_v1(bitmap_git) < 0)
goto failed;
return 0;
failed:
munmap(bitmap_git->map, bitmap_git->map_size);
bitmap_git->map = NULL;
bitmap_git->map_size = 0;
kh_destroy_oid_map(bitmap_git->bitmaps);
bitmap_git->bitmaps = NULL;
kh_destroy_oid_pos(bitmap_git->ext_index.positions);
bitmap_git->ext_index.positions = NULL;
return -1;
}
static int open_pack_bitmap(struct repository *r,
struct bitmap_index *bitmap_git)
{
struct packed_git *p;
int ret = -1;
for (p = get_all_packs(r); p; p = p->next) {
if (open_pack_bitmap_1(bitmap_git, p) == 0) {
ret = 0;
/*
* The only reason to keep looking is to report
* duplicates.
*/
if (!trace2_is_enabled())
break;
}
}
return ret;
}
static int open_midx_bitmap(struct repository *r,
struct bitmap_index *bitmap_git)
{
int ret = -1;
struct multi_pack_index *midx;
assert(!bitmap_git->map);
for (midx = get_multi_pack_index(r); midx; midx = midx->next) {
if (!open_midx_bitmap_1(bitmap_git, midx))
ret = 0;
}
return ret;
}
static int open_bitmap(struct repository *r,
struct bitmap_index *bitmap_git)
{
int found;
assert(!bitmap_git->map);
found = !open_midx_bitmap(r, bitmap_git);
/*
* these will all be skipped if we opened a midx bitmap; but run it
* anyway if tracing is enabled to report the duplicates
*/
if (!found || trace2_is_enabled())
found |= !open_pack_bitmap(r, bitmap_git);
return found ? 0 : -1;
}
struct bitmap_index *prepare_bitmap_git(struct repository *r)
{
struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
if (!open_bitmap(r, bitmap_git) && !load_bitmap(bitmap_git))
return bitmap_git;
free_bitmap_index(bitmap_git);
return NULL;
}
struct bitmap_index *prepare_midx_bitmap_git(struct multi_pack_index *midx)
{
struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
if (!open_midx_bitmap_1(bitmap_git, midx) && !load_bitmap(bitmap_git))
return bitmap_git;
free_bitmap_index(bitmap_git);
return NULL;
}
struct include_data {
struct bitmap_index *bitmap_git;
struct bitmap *base;
struct bitmap *seen;
};
struct bitmap_lookup_table_triplet {
uint32_t commit_pos;
uint64_t offset;
uint32_t xor_row;
};
struct bitmap_lookup_table_xor_item {
struct object_id oid;
uint64_t offset;
};
/*
* Given a `triplet` struct pointer and pointer `p`, this
* function reads the triplet beginning at `p` into the struct.
* Note that this function assumes that there is enough memory
* left for filling the `triplet` struct from `p`.
*/
static int bitmap_lookup_table_get_triplet_by_pointer(struct bitmap_lookup_table_triplet *triplet,
const unsigned char *p)
{
if (!triplet)
return -1;
triplet->commit_pos = get_be32(p);
p += sizeof(uint32_t);
triplet->offset = get_be64(p);
p += sizeof(uint64_t);
triplet->xor_row = get_be32(p);
return 0;
}
/*
* This function gets the raw triplet from `row`'th row in the
* lookup table and fills that data to the `triplet`.
*/
static int bitmap_lookup_table_get_triplet(struct bitmap_index *bitmap_git,
uint32_t pos,
struct bitmap_lookup_table_triplet *triplet)
{
unsigned char *p = NULL;
if (pos >= bitmap_git->entry_count)
return error(_("corrupt bitmap lookup table: triplet position out of index"));
p = bitmap_git->table_lookup + st_mult(pos, BITMAP_LOOKUP_TABLE_TRIPLET_WIDTH);
return bitmap_lookup_table_get_triplet_by_pointer(triplet, p);
}
/*
* Searches for a matching triplet. `commit_pos` is a pointer
* to the wanted commit position value. `table_entry` points to
* a triplet in lookup table. The first 4 bytes of each
* triplet (pointed by `table_entry`) are compared with `*commit_pos`.
*/
static int triplet_cmp(const void *commit_pos, const void *table_entry)
{
uint32_t a = *(uint32_t *)commit_pos;
uint32_t b = get_be32(table_entry);
if (a > b)
return 1;
else if (a < b)
return -1;
return 0;
}
static uint32_t bitmap_bsearch_pos(struct bitmap_index *bitmap_git,
struct object_id *oid,
uint32_t *result)
{
int found;
if (bitmap_is_midx(bitmap_git))
found = bsearch_midx(oid, bitmap_git->midx, result);
else
found = bsearch_pack(oid, bitmap_git->pack, result);
return found;
}
/*
* `bsearch_triplet_by_pos` function searches for the raw triplet
* having commit position same as `commit_pos` and fills `triplet`
* object from the raw triplet. Returns 1 on success and 0 on
* failure.
*/
static int bitmap_bsearch_triplet_by_pos(uint32_t commit_pos,
struct bitmap_index *bitmap_git,
struct bitmap_lookup_table_triplet *triplet)
{
unsigned char *p = bsearch(&commit_pos, bitmap_git->table_lookup, bitmap_git->entry_count,
BITMAP_LOOKUP_TABLE_TRIPLET_WIDTH, triplet_cmp);
if (!p)
return -1;
return bitmap_lookup_table_get_triplet_by_pointer(triplet, p);
}
static struct stored_bitmap *lazy_bitmap_for_commit(struct bitmap_index *bitmap_git,
struct commit *commit)
{
uint32_t commit_pos, xor_row;
uint64_t offset;
int flags;
struct bitmap_lookup_table_triplet triplet;
struct object_id *oid = &commit->object.oid;
struct ewah_bitmap *bitmap;
struct stored_bitmap *xor_bitmap = NULL;
const int bitmap_header_size = 6;
static struct bitmap_lookup_table_xor_item *xor_items = NULL;
static size_t xor_items_nr = 0, xor_items_alloc = 0;
static int is_corrupt = 0;
int xor_flags;
khiter_t hash_pos;
struct bitmap_lookup_table_xor_item *xor_item;
if (is_corrupt)
return NULL;
if (!bitmap_bsearch_pos(bitmap_git, oid, &commit_pos))
return NULL;
if (bitmap_bsearch_triplet_by_pos(commit_pos, bitmap_git, &triplet) < 0)
return NULL;
xor_items_nr = 0;
offset = triplet.offset;
xor_row = triplet.xor_row;
while (xor_row != 0xffffffff) {
ALLOC_GROW(xor_items, xor_items_nr + 1, xor_items_alloc);
if (xor_items_nr + 1 >= bitmap_git->entry_count) {
error(_("corrupt bitmap lookup table: xor chain exceeds entry count"));
goto corrupt;
}
if (bitmap_lookup_table_get_triplet(bitmap_git, xor_row, &triplet) < 0)
goto corrupt;
xor_item = &xor_items[xor_items_nr];
xor_item->offset = triplet.offset;
if (nth_bitmap_object_oid(bitmap_git, &xor_item->oid, triplet.commit_pos) < 0) {
error(_("corrupt bitmap lookup table: commit index %u out of range"),
triplet.commit_pos);
goto corrupt;
}
hash_pos = kh_get_oid_map(bitmap_git->bitmaps, xor_item->oid);
/*
* If desired bitmap is already stored, we don't need
* to iterate further. Because we know that bitmaps
* that are needed to be parsed to parse this bitmap
* has already been stored. So, assign this stored bitmap
* to the xor_bitmap.
*/
if (hash_pos < kh_end(bitmap_git->bitmaps) &&
(xor_bitmap = kh_value(bitmap_git->bitmaps, hash_pos)))
break;
xor_items_nr++;
xor_row = triplet.xor_row;
}
while (xor_items_nr) {
xor_item = &xor_items[xor_items_nr - 1];
bitmap_git->map_pos = xor_item->offset;
if (bitmap_git->map_size - bitmap_git->map_pos < bitmap_header_size) {
error(_("corrupt ewah bitmap: truncated header for bitmap of commit \"%s\""),
oid_to_hex(&xor_item->oid));
goto corrupt;
}
bitmap_git->map_pos += sizeof(uint32_t) + sizeof(uint8_t);
xor_flags = read_u8(bitmap_git->map, &bitmap_git->map_pos);
bitmap = read_bitmap_1(bitmap_git);
if (!bitmap)
goto corrupt;
xor_bitmap = store_bitmap(bitmap_git, bitmap, &xor_item->oid, xor_bitmap, xor_flags);
xor_items_nr--;
}
bitmap_git->map_pos = offset;
if (bitmap_git->map_size - bitmap_git->map_pos < bitmap_header_size) {
error(_("corrupt ewah bitmap: truncated header for bitmap of commit \"%s\""),
oid_to_hex(oid));
goto corrupt;
}
/*
* Don't bother reading the commit's index position or its xor
* offset:
*
* - The commit's index position is irrelevant to us, since
* load_bitmap_entries_v1 only uses it to learn the object
* id which is used to compute the hashmap's key. We already
* have an object id, so no need to look it up again.
*
* - The xor_offset is unusable for us, since it specifies how
* many entries previous to ours we should look at. This
* makes sense when reading the bitmaps sequentially (as in
* load_bitmap_entries_v1()), since we can keep track of
* each bitmap as we read them.
*
* But it can't work for us, since the bitmap's don't have a
* fixed size. So we learn the position of the xor'd bitmap
* from the commit table (and resolve it to a bitmap in the
* above if-statement).
*
* Instead, we can skip ahead and immediately read the flags and
* ewah bitmap.
*/
bitmap_git->map_pos += sizeof(uint32_t) + sizeof(uint8_t);
flags = read_u8(bitmap_git->map, &bitmap_git->map_pos);
bitmap = read_bitmap_1(bitmap_git);
if (!bitmap)
goto corrupt;
return store_bitmap(bitmap_git, bitmap, oid, xor_bitmap, flags);
corrupt:
free(xor_items);
is_corrupt = 1;
return NULL;
}
struct ewah_bitmap *bitmap_for_commit(struct bitmap_index *bitmap_git,
struct commit *commit)
{
khiter_t hash_pos = kh_get_oid_map(bitmap_git->bitmaps,
commit->object.oid);
if (hash_pos >= kh_end(bitmap_git->bitmaps)) {
struct stored_bitmap *bitmap = NULL;
if (!bitmap_git->table_lookup)
return NULL;
/* this is a fairly hot codepath - no trace2_region please */
/* NEEDSWORK: cache misses aren't recorded */
bitmap = lazy_bitmap_for_commit(bitmap_git, commit);
if (!bitmap)
return NULL;
return lookup_stored_bitmap(bitmap);
}
return lookup_stored_bitmap(kh_value(bitmap_git->bitmaps, hash_pos));
}
static inline int bitmap_position_extended(struct bitmap_index *bitmap_git,
const struct object_id *oid)
{
kh_oid_pos_t *positions = bitmap_git->ext_index.positions;
khiter_t pos = kh_get_oid_pos(positions, *oid);
if (pos < kh_end(positions)) {
int bitmap_pos = kh_value(positions, pos);
return bitmap_pos + bitmap_num_objects(bitmap_git);
}
return -1;
}
static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git,
const struct object_id *oid)
{
uint32_t pos;
off_t offset = find_pack_entry_one(oid->hash, bitmap_git->pack);
if (!offset)
return -1;
if (offset_to_pack_pos(bitmap_git->pack, offset, &pos) < 0)
return -1;
return pos;
}
static int bitmap_position_midx(struct bitmap_index *bitmap_git,
const struct object_id *oid)
{
uint32_t want, got;
if (!bsearch_midx(oid, bitmap_git->midx, &want))
return -1;
if (midx_to_pack_pos(bitmap_git->midx, want, &got) < 0)
return -1;
return got;
}
static int bitmap_position(struct bitmap_index *bitmap_git,
const struct object_id *oid)
{
int pos;
if (bitmap_is_midx(bitmap_git))
pos = bitmap_position_midx(bitmap_git, oid);
else
pos = bitmap_position_packfile(bitmap_git, oid);
return (pos >= 0) ? pos : bitmap_position_extended(bitmap_git, oid);
}
static int ext_index_add_object(struct bitmap_index *bitmap_git,
struct object *object, const char *name)
{
struct eindex *eindex = &bitmap_git->ext_index;
khiter_t hash_pos;
int hash_ret;
int bitmap_pos;
hash_pos = kh_put_oid_pos(eindex->positions, object->oid, &hash_ret);
if (hash_ret > 0) {
if (eindex->count >= eindex->alloc) {
eindex->alloc = (eindex->alloc + 16) * 3 / 2;
REALLOC_ARRAY(eindex->objects, eindex->alloc);
REALLOC_ARRAY(eindex->hashes, eindex->alloc);
}
bitmap_pos = eindex->count;
eindex->objects[eindex->count] = object;
eindex->hashes[eindex->count] = pack_name_hash(name);
kh_value(eindex->positions, hash_pos) = bitmap_pos;
eindex->count++;
} else {
bitmap_pos = kh_value(eindex->positions, hash_pos);
}
return bitmap_pos + bitmap_num_objects(bitmap_git);
}
struct bitmap_show_data {
struct bitmap_index *bitmap_git;
struct bitmap *base;
};
static void show_object(struct object *object, const char *name, void *data_)
{
struct bitmap_show_data *data = data_;
int bitmap_pos;
bitmap_pos = bitmap_position(data->bitmap_git, &object->oid);
if (bitmap_pos < 0)
bitmap_pos = ext_index_add_object(data->bitmap_git, object,
name);
bitmap_set(data->base, bitmap_pos);
}
static void show_commit(struct commit *commit UNUSED,
void *data UNUSED)
{
}
static int add_to_include_set(struct bitmap_index *bitmap_git,
struct include_data *data,
struct commit *commit,
int bitmap_pos)
{
struct ewah_bitmap *partial;
if (data->seen && bitmap_get(data->seen, bitmap_pos))
return 0;
if (bitmap_get(data->base, bitmap_pos))
return 0;
partial = bitmap_for_commit(bitmap_git, commit);
if (partial) {
bitmap_or_ewah(data->base, partial);
return 0;
}
bitmap_set(data->base, bitmap_pos);
return 1;
}
static int should_include(struct commit *commit, void *_data)
{
struct include_data *data = _data;
int bitmap_pos;
bitmap_pos = bitmap_position(data->bitmap_git, &commit->object.oid);
if (bitmap_pos < 0)
bitmap_pos = ext_index_add_object(data->bitmap_git,
(struct object *)commit,
NULL);
if (!add_to_include_set(data->bitmap_git, data, commit, bitmap_pos)) {
struct commit_list *parent = commit->parents;
while (parent) {
parent->item->object.flags |= SEEN;
parent = parent->next;
}
return 0;
}
return 1;
}
static int should_include_obj(struct object *obj, void *_data)
{
struct include_data *data = _data;
int bitmap_pos;
bitmap_pos = bitmap_position(data->bitmap_git, &obj->oid);
if (bitmap_pos < 0)
return 1;
if ((data->seen && bitmap_get(data->seen, bitmap_pos)) ||
bitmap_get(data->base, bitmap_pos)) {
obj->flags |= SEEN;
return 0;
}
return 1;
}
static int add_commit_to_bitmap(struct bitmap_index *bitmap_git,
struct bitmap **base,
struct commit *commit)
{
struct ewah_bitmap *or_with = bitmap_for_commit(bitmap_git, commit);
if (!or_with)
return 0;
if (!*base)
*base = ewah_to_bitmap(or_with);
else
bitmap_or_ewah(*base, or_with);
return 1;
}
static struct bitmap *find_objects(struct bitmap_index *bitmap_git,
struct rev_info *revs,
struct object_list *roots,
struct bitmap *seen)
{
struct bitmap *base = NULL;
int needs_walk = 0;
struct object_list *not_mapped = NULL;
/*
* Go through all the roots for the walk. The ones that have bitmaps
* on the bitmap index will be `or`ed together to form an initial
* global reachability analysis.
*
* The ones without bitmaps in the index will be stored in the
* `not_mapped_list` for further processing.
*/
while (roots) {
struct object *object = roots->item;
roots = roots->next;
if (object->type == OBJ_COMMIT &&
add_commit_to_bitmap(bitmap_git, &base, (struct commit *)object)) {
object->flags |= SEEN;
continue;
}
object_list_insert(object, &not_mapped);
}
/*
* Best case scenario: We found bitmaps for all the roots,
* so the resulting `or` bitmap has the full reachability analysis
*/
if (!not_mapped)
return base;
roots = not_mapped;
/*
* Let's iterate through all the roots that don't have bitmaps to
* check if we can determine them to be reachable from the existing
* global bitmap.
*
* If we cannot find them in the existing global bitmap, we'll need
* to push them to an actual walk and run it until we can confirm
* they are reachable
*/
while (roots) {
struct object *object = roots->item;
int pos;
roots = roots->next;
pos = bitmap_position(bitmap_git, &object->oid);
if (pos < 0 || base == NULL || !bitmap_get(base, pos)) {
object->flags &= ~UNINTERESTING;
add_pending_object(revs, object, "");
needs_walk = 1;
} else {
object->flags |= SEEN;
}
}
if (needs_walk) {
struct include_data incdata;
struct bitmap_show_data show_data;
if (!base)
base = bitmap_new();
incdata.bitmap_git = bitmap_git;
incdata.base = base;
incdata.seen = seen;
revs->include_check = should_include;
revs->include_check_obj = should_include_obj;
revs->include_check_data = &incdata;
if (prepare_revision_walk(revs))
die(_("revision walk setup failed"));
show_data.bitmap_git = bitmap_git;
show_data.base = base;
traverse_commit_list(revs,
show_commit, show_object,
&show_data);
revs->include_check = NULL;
revs->include_check_obj = NULL;
revs->include_check_data = NULL;
}
return base;
}
static void show_extended_objects(struct bitmap_index *bitmap_git,
struct rev_info *revs,
show_reachable_fn show_reach)
{
struct bitmap *objects = bitmap_git->result;
struct eindex *eindex = &bitmap_git->ext_index;
uint32_t i;
for (i = 0; i < eindex->count; ++i) {
struct object *obj;
if (!bitmap_get(objects, bitmap_num_objects(bitmap_git) + i))
continue;
obj = eindex->objects[i];
if ((obj->type == OBJ_BLOB && !revs->blob_objects) ||
(obj->type == OBJ_TREE && !revs->tree_objects) ||
(obj->type == OBJ_TAG && !revs->tag_objects))
continue;
show_reach(&obj->oid, obj->type, 0, eindex->hashes[i], NULL, 0);
}
}
static void init_type_iterator(struct ewah_iterator *it,
struct bitmap_index *bitmap_git,
enum object_type type)
{
switch (type) {
case OBJ_COMMIT:
ewah_iterator_init(it, bitmap_git->commits);
break;
case OBJ_TREE:
ewah_iterator_init(it, bitmap_git->trees);
break;
case OBJ_BLOB:
ewah_iterator_init(it, bitmap_git->blobs);
break;
case OBJ_TAG:
ewah_iterator_init(it, bitmap_git->tags);
break;
default:
BUG("object type %d not stored by bitmap type index", type);
break;
}
}
static void show_objects_for_type(
struct bitmap_index *bitmap_git,
enum object_type object_type,
show_reachable_fn show_reach)
{
size_t i = 0;
uint32_t offset;
struct ewah_iterator it;
eword_t filter;
struct bitmap *objects = bitmap_git->result;
init_type_iterator(&it, bitmap_git, object_type);
for (i = 0; i < objects->word_alloc &&
ewah_iterator_next(&filter, &it); i++) {
eword_t word = objects->words[i] & filter;
size_t pos = (i * BITS_IN_EWORD);
if (!word)
continue;
for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
struct packed_git *pack;
struct object_id oid;
uint32_t hash = 0, index_pos;
off_t ofs;
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
if (bitmap_is_midx(bitmap_git)) {
struct multi_pack_index *m = bitmap_git->midx;
uint32_t pack_id;
index_pos = pack_pos_to_midx(m, pos + offset);
ofs = nth_midxed_offset(m, index_pos);
nth_midxed_object_oid(&oid, m, index_pos);
pack_id = nth_midxed_pack_int_id(m, index_pos);
pack = bitmap_git->midx->packs[pack_id];
} else {
index_pos = pack_pos_to_index(bitmap_git->pack, pos + offset);
ofs = pack_pos_to_offset(bitmap_git->pack, pos + offset);
nth_bitmap_object_oid(bitmap_git, &oid, index_pos);
pack = bitmap_git->pack;
}
if (bitmap_git->hashes)
hash = get_be32(bitmap_git->hashes + index_pos);
show_reach(&oid, object_type, 0, hash, pack, ofs);
}
}
}
static int in_bitmapped_pack(struct bitmap_index *bitmap_git,
struct object_list *roots)
{
while (roots) {
struct object *object = roots->item;
roots = roots->next;
if (bitmap_is_midx(bitmap_git)) {
if (bsearch_midx(&object->oid, bitmap_git->midx, NULL))
return 1;
} else {
if (find_pack_entry_one(object->oid.hash, bitmap_git->pack) > 0)
return 1;
}
}
return 0;
}
static struct bitmap *find_tip_objects(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
enum object_type type)
{
struct bitmap *result = bitmap_new();
struct object_list *p;
for (p = tip_objects; p; p = p->next) {
int pos;
if (p->item->type != type)
continue;
pos = bitmap_position(bitmap_git, &p->item->oid);
if (pos < 0)
continue;
bitmap_set(result, pos);
}
return result;
}
static void filter_bitmap_exclude_type(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
struct bitmap *to_filter,
enum object_type type)
{
struct eindex *eindex = &bitmap_git->ext_index;
struct bitmap *tips;
struct ewah_iterator it;
eword_t mask;
uint32_t i;
/*
* The non-bitmap version of this filter never removes
* objects which the other side specifically asked for,
* so we must match that behavior.
*/
tips = find_tip_objects(bitmap_git, tip_objects, type);
/*
* We can use the type-level bitmap for 'type' to work in whole
* words for the objects that are actually in the bitmapped
* packfile.
*/
for (i = 0, init_type_iterator(&it, bitmap_git, type);
i < to_filter->word_alloc && ewah_iterator_next(&mask, &it);
i++) {
if (i < tips->word_alloc)
mask &= ~tips->words[i];
to_filter->words[i] &= ~mask;
}
/*
* Clear any objects that weren't in the packfile (and so would
* not have been caught by the loop above. We'll have to check
* them individually.
*/
for (i = 0; i < eindex->count; i++) {
uint32_t pos = i + bitmap_num_objects(bitmap_git);
if (eindex->objects[i]->type == type &&
bitmap_get(to_filter, pos) &&
!bitmap_get(tips, pos))
bitmap_unset(to_filter, pos);
}
bitmap_free(tips);
}
static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
struct bitmap *to_filter)
{
filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter,
OBJ_BLOB);
}
static unsigned long get_size_by_pos(struct bitmap_index *bitmap_git,
uint32_t pos)
{
unsigned long size;
struct object_info oi = OBJECT_INFO_INIT;
oi.sizep = &size;
if (pos < bitmap_num_objects(bitmap_git)) {
struct packed_git *pack;
off_t ofs;
if (bitmap_is_midx(bitmap_git)) {
uint32_t midx_pos = pack_pos_to_midx(bitmap_git->midx, pos);
uint32_t pack_id = nth_midxed_pack_int_id(bitmap_git->midx, midx_pos);
pack = bitmap_git->midx->packs[pack_id];
ofs = nth_midxed_offset(bitmap_git->midx, midx_pos);
} else {
pack = bitmap_git->pack;
ofs = pack_pos_to_offset(pack, pos);
}
if (packed_object_info(the_repository, pack, ofs, &oi) < 0) {
struct object_id oid;
nth_bitmap_object_oid(bitmap_git, &oid,
pack_pos_to_index(pack, pos));
die(_("unable to get size of %s"), oid_to_hex(&oid));
}
} else {
struct eindex *eindex = &bitmap_git->ext_index;
struct object *obj = eindex->objects[pos - bitmap_num_objects(bitmap_git)];
if (oid_object_info_extended(the_repository, &obj->oid, &oi, 0) < 0)
die(_("unable to get size of %s"), oid_to_hex(&obj->oid));
}
return size;
}
static void filter_bitmap_blob_limit(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
struct bitmap *to_filter,
unsigned long limit)
{
struct eindex *eindex = &bitmap_git->ext_index;
struct bitmap *tips;
struct ewah_iterator it;
eword_t mask;
uint32_t i;
tips = find_tip_objects(bitmap_git, tip_objects, OBJ_BLOB);
for (i = 0, init_type_iterator(&it, bitmap_git, OBJ_BLOB);
i < to_filter->word_alloc && ewah_iterator_next(&mask, &it);
i++) {
eword_t word = to_filter->words[i] & mask;
unsigned offset;
for (offset = 0; offset < BITS_IN_EWORD; offset++) {
uint32_t pos;
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
pos = i * BITS_IN_EWORD + offset;
if (!bitmap_get(tips, pos) &&
get_size_by_pos(bitmap_git, pos) >= limit)
bitmap_unset(to_filter, pos);
}
}
for (i = 0; i < eindex->count; i++) {
uint32_t pos = i + bitmap_num_objects(bitmap_git);
if (eindex->objects[i]->type == OBJ_BLOB &&
bitmap_get(to_filter, pos) &&
!bitmap_get(tips, pos) &&
get_size_by_pos(bitmap_git, pos) >= limit)
bitmap_unset(to_filter, pos);
}
bitmap_free(tips);
}
static void filter_bitmap_tree_depth(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
struct bitmap *to_filter,
unsigned long limit)
{
if (limit)
BUG("filter_bitmap_tree_depth given non-zero limit");
filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter,
OBJ_TREE);
filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter,
OBJ_BLOB);
}
static void filter_bitmap_object_type(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
struct bitmap *to_filter,
enum object_type object_type)
{
if (object_type < OBJ_COMMIT || object_type > OBJ_TAG)
BUG("filter_bitmap_object_type given invalid object");
if (object_type != OBJ_TAG)
filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter, OBJ_TAG);
if (object_type != OBJ_COMMIT)
filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter, OBJ_COMMIT);
if (object_type != OBJ_TREE)
filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter, OBJ_TREE);
if (object_type != OBJ_BLOB)
filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter, OBJ_BLOB);
}
static int filter_bitmap(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
struct bitmap *to_filter,
struct list_objects_filter_options *filter)
{
if (!filter || filter->choice == LOFC_DISABLED)
return 0;
if (filter->choice == LOFC_BLOB_NONE) {
if (bitmap_git)
filter_bitmap_blob_none(bitmap_git, tip_objects,
to_filter);
return 0;
}
if (filter->choice == LOFC_BLOB_LIMIT) {
if (bitmap_git)
filter_bitmap_blob_limit(bitmap_git, tip_objects,
to_filter,
filter->blob_limit_value);
return 0;
}
if (filter->choice == LOFC_TREE_DEPTH &&
filter->tree_exclude_depth == 0) {
if (bitmap_git)
filter_bitmap_tree_depth(bitmap_git, tip_objects,
to_filter,
filter->tree_exclude_depth);
return 0;
}
if (filter->choice == LOFC_OBJECT_TYPE) {
if (bitmap_git)
filter_bitmap_object_type(bitmap_git, tip_objects,
to_filter,
filter->object_type);
return 0;
}
if (filter->choice == LOFC_COMBINE) {
int i;
for (i = 0; i < filter->sub_nr; i++) {
if (filter_bitmap(bitmap_git, tip_objects, to_filter,
&filter->sub[i]) < 0)
return -1;
}
return 0;
}
/* filter choice not handled */
return -1;
}
static int can_filter_bitmap(struct list_objects_filter_options *filter)
{
return !filter_bitmap(NULL, NULL, NULL, filter);
}
struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs,
int filter_provided_objects)
{
unsigned int i;
struct object_list *wants = NULL;
struct object_list *haves = NULL;
struct bitmap *wants_bitmap = NULL;
struct bitmap *haves_bitmap = NULL;
struct bitmap_index *bitmap_git;
/*
* We can't do pathspec limiting with bitmaps, because we don't know
* which commits are associated with which object changes (let alone
* even which objects are associated with which paths).
*/
if (revs->prune)
return NULL;
if (!can_filter_bitmap(&revs->filter))
return NULL;
/* try to open a bitmapped pack, but don't parse it yet
* because we may not need to use it */
CALLOC_ARRAY(bitmap_git, 1);
if (open_bitmap(revs->repo, bitmap_git) < 0)
goto cleanup;
for (i = 0; i < revs->pending.nr; ++i) {
struct object *object = revs->pending.objects[i].item;
if (object->type == OBJ_NONE)
parse_object_or_die(&object->oid, NULL);
while (object->type == OBJ_TAG) {
struct tag *tag = (struct tag *) object;
if (object->flags & UNINTERESTING)
object_list_insert(object, &haves);
else
object_list_insert(object, &wants);
object = parse_object_or_die(get_tagged_oid(tag), NULL);
object->flags |= (tag->object.flags & UNINTERESTING);
}
if (object->flags & UNINTERESTING)
object_list_insert(object, &haves);
else
object_list_insert(object, &wants);
}
/*
* if we have a HAVES list, but none of those haves is contained
* in the packfile that has a bitmap, we don't have anything to
* optimize here
*/
if (haves && !in_bitmapped_pack(bitmap_git, haves))
goto cleanup;
/* if we don't want anything, we're done here */
if (!wants)
goto cleanup;
/*
* now we're going to use bitmaps, so load the actual bitmap entries
* from disk. this is the point of no return; after this the rev_list
* becomes invalidated and we must perform the revwalk through bitmaps
*/
if (load_bitmap(bitmap_git) < 0)
goto cleanup;
object_array_clear(&revs->pending);
if (haves) {
revs->ignore_missing_links = 1;
haves_bitmap = find_objects(bitmap_git, revs, haves, NULL);
reset_revision_walk();
revs->ignore_missing_links = 0;
if (!haves_bitmap)
BUG("failed to perform bitmap walk");
}
wants_bitmap = find_objects(bitmap_git, revs, wants, haves_bitmap);
if (!wants_bitmap)
BUG("failed to perform bitmap walk");
if (haves_bitmap)
bitmap_and_not(wants_bitmap, haves_bitmap);
filter_bitmap(bitmap_git,
(revs->filter.choice && filter_provided_objects) ? NULL : wants,
wants_bitmap,
&revs->filter);
bitmap_git->result = wants_bitmap;
bitmap_git->haves = haves_bitmap;
object_list_free(&wants);
object_list_free(&haves);
return bitmap_git;
cleanup:
free_bitmap_index(bitmap_git);
object_list_free(&wants);
object_list_free(&haves);
return NULL;
}
/*
* -1 means "stop trying further objects"; 0 means we may or may not have
* reused, but you can keep feeding bits.
*/
static int try_partial_reuse(struct packed_git *pack,
size_t pos,
struct bitmap *reuse,
struct pack_window **w_curs)
{
off_t offset, delta_obj_offset;
enum object_type type;
unsigned long size;
/*
* try_partial_reuse() is called either on (a) objects in the
* bitmapped pack (in the case of a single-pack bitmap) or (b)
* objects in the preferred pack of a multi-pack bitmap.
* Importantly, the latter can pretend as if only a single pack
* exists because:
*
* - The first pack->num_objects bits of a MIDX bitmap are
* reserved for the preferred pack, and
*
* - Ties due to duplicate objects are always resolved in
* favor of the preferred pack.
*
* Therefore we do not need to ever ask the MIDX for its copy of
* an object by OID, since it will always select it from the
* preferred pack. Likewise, the selected copy of the base
* object for any deltas will reside in the same pack.
*
* This means that we can reuse pos when looking up the bit in
* the reuse bitmap, too, since bits corresponding to the
* preferred pack precede all bits from other packs.
*/
if (pos >= pack->num_objects)
return -1; /* not actually in the pack or MIDX preferred pack */
offset = delta_obj_offset = pack_pos_to_offset(pack, pos);
type = unpack_object_header(pack, w_curs, &offset, &size);
if (type < 0)
return -1; /* broken packfile, punt */
if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA) {
off_t base_offset;
uint32_t base_pos;
/*
* Find the position of the base object so we can look it up
* in our bitmaps. If we can't come up with an offset, or if
* that offset is not in the revidx, the pack is corrupt.
* There's nothing we can do, so just punt on this object,
* and the normal slow path will complain about it in
* more detail.
*/
base_offset = get_delta_base(pack, w_curs, &offset, type,
delta_obj_offset);
if (!base_offset)
return 0;
if (offset_to_pack_pos(pack, base_offset, &base_pos) < 0)
return 0;
/*
* We assume delta dependencies always point backwards. This
* lets us do a single pass, and is basically always true
* due to the way OFS_DELTAs work. You would not typically
* find REF_DELTA in a bitmapped pack, since we only bitmap
* packs we write fresh, and OFS_DELTA is the default). But
* let's double check to make sure the pack wasn't written with
* odd parameters.
*/
if (base_pos >= pos)
return 0;
/*
* And finally, if we're not sending the base as part of our
* reuse chunk, then don't send this object either. The base
* would come after us, along with other objects not
* necessarily in the pack, which means we'd need to convert
* to REF_DELTA on the fly. Better to just let the normal
* object_entry code path handle it.
*/
if (!bitmap_get(reuse, base_pos))
return 0;
}
/*
* If we got here, then the object is OK to reuse. Mark it.
*/
bitmap_set(reuse, pos);
return 0;
}
uint32_t midx_preferred_pack(struct bitmap_index *bitmap_git)
{
struct multi_pack_index *m = bitmap_git->midx;
if (!m)
BUG("midx_preferred_pack: requires non-empty MIDX");
return nth_midxed_pack_int_id(m, pack_pos_to_midx(bitmap_git->midx, 0));
}
int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
struct packed_git **packfile_out,
uint32_t *entries,
struct bitmap **reuse_out)
{
struct packed_git *pack;
struct bitmap *result = bitmap_git->result;
struct bitmap *reuse;
struct pack_window *w_curs = NULL;
size_t i = 0;
uint32_t offset;
uint32_t objects_nr;
assert(result);
load_reverse_index(bitmap_git);
if (bitmap_is_midx(bitmap_git))
pack = bitmap_git->midx->packs[midx_preferred_pack(bitmap_git)];
else
pack = bitmap_git->pack;
objects_nr = pack->num_objects;
while (i < result->word_alloc && result->words[i] == (eword_t)~0)
i++;
/*
* Don't mark objects not in the packfile or preferred pack. This bitmap
* marks objects eligible for reuse, but the pack-reuse code only
* understands how to reuse a single pack. Since the preferred pack is
* guaranteed to have all bases for its deltas (in a multi-pack bitmap),
* we use it instead of another pack. In single-pack bitmaps, the choice
* is made for us.
*/
if (i > objects_nr / BITS_IN_EWORD)
i = objects_nr / BITS_IN_EWORD;
reuse = bitmap_word_alloc(i);
memset(reuse->words, 0xFF, i * sizeof(eword_t));
for (; i < result->word_alloc; ++i) {
eword_t word = result->words[i];
size_t pos = (i * BITS_IN_EWORD);
for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
if (try_partial_reuse(pack, pos + offset,
reuse, &w_curs) < 0) {
/*
* try_partial_reuse indicated we couldn't reuse
* any bits, so there is no point in trying more
* bits in the current word, or any other words
* in result.
*
* Jump out of both loops to avoid future
* unnecessary calls to try_partial_reuse.
*/
goto done;
}
}
}
done:
unuse_pack(&w_curs);
*entries = bitmap_popcount(reuse);
if (!*entries) {
bitmap_free(reuse);
return -1;
}
/*
* Drop any reused objects from the result, since they will not
* need to be handled separately.
*/
bitmap_and_not(result, reuse);
*packfile_out = pack;
*reuse_out = reuse;
return 0;
}
int bitmap_walk_contains(struct bitmap_index *bitmap_git,
struct bitmap *bitmap, const struct object_id *oid)
{
int idx;
if (!bitmap)
return 0;
idx = bitmap_position(bitmap_git, oid);
return idx >= 0 && bitmap_get(bitmap, idx);
}
void traverse_bitmap_commit_list(struct bitmap_index *bitmap_git,
struct rev_info *revs,
show_reachable_fn show_reachable)
{
assert(bitmap_git->result);
show_objects_for_type(bitmap_git, OBJ_COMMIT, show_reachable);
if (revs->tree_objects)
show_objects_for_type(bitmap_git, OBJ_TREE, show_reachable);
if (revs->blob_objects)
show_objects_for_type(bitmap_git, OBJ_BLOB, show_reachable);
if (revs->tag_objects)
show_objects_for_type(bitmap_git, OBJ_TAG, show_reachable);
show_extended_objects(bitmap_git, revs, show_reachable);
}
static uint32_t count_object_type(struct bitmap_index *bitmap_git,
enum object_type type)
{
struct bitmap *objects = bitmap_git->result;
struct eindex *eindex = &bitmap_git->ext_index;
uint32_t i = 0, count = 0;
struct ewah_iterator it;
eword_t filter;
init_type_iterator(&it, bitmap_git, type);
while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
eword_t word = objects->words[i++] & filter;
count += ewah_bit_popcount64(word);
}
for (i = 0; i < eindex->count; ++i) {
if (eindex->objects[i]->type == type &&
bitmap_get(objects, bitmap_num_objects(bitmap_git) + i))
count++;
}
return count;
}
void count_bitmap_commit_list(struct bitmap_index *bitmap_git,
uint32_t *commits, uint32_t *trees,
uint32_t *blobs, uint32_t *tags)
{
assert(bitmap_git->result);
if (commits)
*commits = count_object_type(bitmap_git, OBJ_COMMIT);
if (trees)
*trees = count_object_type(bitmap_git, OBJ_TREE);
if (blobs)
*blobs = count_object_type(bitmap_git, OBJ_BLOB);
if (tags)
*tags = count_object_type(bitmap_git, OBJ_TAG);
}
struct bitmap_test_data {
struct bitmap_index *bitmap_git;
struct bitmap *base;
struct bitmap *commits;
struct bitmap *trees;
struct bitmap *blobs;
struct bitmap *tags;
struct progress *prg;
size_t seen;
};
static void test_bitmap_type(struct bitmap_test_data *tdata,
struct object *obj, int pos)
{
enum object_type bitmap_type = OBJ_NONE;
int bitmaps_nr = 0;
if (bitmap_get(tdata->commits, pos)) {
bitmap_type = OBJ_COMMIT;
bitmaps_nr++;
}
if (bitmap_get(tdata->trees, pos)) {
bitmap_type = OBJ_TREE;
bitmaps_nr++;
}
if (bitmap_get(tdata->blobs, pos)) {
bitmap_type = OBJ_BLOB;
bitmaps_nr++;
}
if (bitmap_get(tdata->tags, pos)) {
bitmap_type = OBJ_TAG;
bitmaps_nr++;
}
if (bitmap_type == OBJ_NONE)
die(_("object '%s' not found in type bitmaps"),
oid_to_hex(&obj->oid));
if (bitmaps_nr > 1)
die(_("object '%s' does not have a unique type"),
oid_to_hex(&obj->oid));
if (bitmap_type != obj->type)
die(_("object '%s': real type '%s', expected: '%s'"),
oid_to_hex(&obj->oid),
type_name(obj->type),
type_name(bitmap_type));
}
static void test_show_object(struct object *object,
const char *name UNUSED,
void *data)
{
struct bitmap_test_data *tdata = data;
int bitmap_pos;
bitmap_pos = bitmap_position(tdata->bitmap_git, &object->oid);
if (bitmap_pos < 0)
die(_("object not in bitmap: '%s'"), oid_to_hex(&object->oid));
test_bitmap_type(tdata, object, bitmap_pos);
bitmap_set(tdata->base, bitmap_pos);
display_progress(tdata->prg, ++tdata->seen);
}
static void test_show_commit(struct commit *commit, void *data)
{
struct bitmap_test_data *tdata = data;
int bitmap_pos;
bitmap_pos = bitmap_position(tdata->bitmap_git,
&commit->object.oid);
if (bitmap_pos < 0)
die(_("object not in bitmap: '%s'"), oid_to_hex(&commit->object.oid));
test_bitmap_type(tdata, &commit->object, bitmap_pos);
bitmap_set(tdata->base, bitmap_pos);
display_progress(tdata->prg, ++tdata->seen);
}
void test_bitmap_walk(struct rev_info *revs)
{
struct object *root;
struct bitmap *result = NULL;
size_t result_popcnt;
struct bitmap_test_data tdata;
struct bitmap_index *bitmap_git;
struct ewah_bitmap *bm;
if (!(bitmap_git = prepare_bitmap_git(revs->repo)))
die(_("failed to load bitmap indexes"));
if (revs->pending.nr != 1)
die(_("you must specify exactly one commit to test"));
fprintf_ln(stderr, "Bitmap v%d test (%d entries%s)",
bitmap_git->version,
bitmap_git->entry_count,
bitmap_git->table_lookup ? "" : " loaded");
root = revs->pending.objects[0].item;
bm = bitmap_for_commit(bitmap_git, (struct commit *)root);
if (bm) {
fprintf_ln(stderr, "Found bitmap for '%s'. %d bits / %08x checksum",
oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm));
result = ewah_to_bitmap(bm);
}
if (!result)
die(_("commit '%s' doesn't have an indexed bitmap"), oid_to_hex(&root->oid));
revs->tag_objects = 1;
revs->tree_objects = 1;
revs->blob_objects = 1;
result_popcnt = bitmap_popcount(result);
if (prepare_revision_walk(revs))
die(_("revision walk setup failed"));
tdata.bitmap_git = bitmap_git;
tdata.base = bitmap_new();
tdata.commits = ewah_to_bitmap(bitmap_git->commits);
tdata.trees = ewah_to_bitmap(bitmap_git->trees);
tdata.blobs = ewah_to_bitmap(bitmap_git->blobs);
tdata.tags = ewah_to_bitmap(bitmap_git->tags);
tdata.prg = start_progress("Verifying bitmap entries", result_popcnt);
tdata.seen = 0;
traverse_commit_list(revs, &test_show_commit, &test_show_object, &tdata);
stop_progress(&tdata.prg);
if (bitmap_equals(result, tdata.base))
fprintf_ln(stderr, "OK!");
else
die(_("mismatch in bitmap results"));
bitmap_free(result);
bitmap_free(tdata.base);
bitmap_free(tdata.commits);
bitmap_free(tdata.trees);
bitmap_free(tdata.blobs);
bitmap_free(tdata.tags);
free_bitmap_index(bitmap_git);
}
int test_bitmap_commits(struct repository *r)
{
struct object_id oid;
MAYBE_UNUSED void *value;
struct bitmap_index *bitmap_git = prepare_bitmap_git(r);
if (!bitmap_git)
die(_("failed to load bitmap indexes"));
/*
* As this function is only used to print bitmap selected
* commits, we don't have to read the commit table.
*/
if (bitmap_git->table_lookup) {
if (load_bitmap_entries_v1(bitmap_git) < 0)
die(_("failed to load bitmap indexes"));
}
kh_foreach(bitmap_git->bitmaps, oid, value, {
printf_ln("%s", oid_to_hex(&oid));
});
free_bitmap_index(bitmap_git);
return 0;
}
int test_bitmap_hashes(struct repository *r)
{
struct bitmap_index *bitmap_git = prepare_bitmap_git(r);
struct object_id oid;
uint32_t i, index_pos;
if (!bitmap_git || !bitmap_git->hashes)
goto cleanup;
for (i = 0; i < bitmap_num_objects(bitmap_git); i++) {
if (bitmap_is_midx(bitmap_git))
index_pos = pack_pos_to_midx(bitmap_git->midx, i);
else
index_pos = pack_pos_to_index(bitmap_git->pack, i);
nth_bitmap_object_oid(bitmap_git, &oid, index_pos);
printf_ln("%s %"PRIu32"",
oid_to_hex(&oid), get_be32(bitmap_git->hashes + index_pos));
}
cleanup:
free_bitmap_index(bitmap_git);
return 0;
}
int rebuild_bitmap(const uint32_t *reposition,
struct ewah_bitmap *source,
struct bitmap *dest)
{
uint32_t pos = 0;
struct ewah_iterator it;
eword_t word;
ewah_iterator_init(&it, source);
while (ewah_iterator_next(&word, &it)) {
uint32_t offset, bit_pos;
for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
bit_pos = reposition[pos + offset];
if (bit_pos > 0)
bitmap_set(dest, bit_pos - 1);
else /* can't reuse, we don't have the object */
return -1;
}
pos += BITS_IN_EWORD;
}
return 0;
}
uint32_t *create_bitmap_mapping(struct bitmap_index *bitmap_git,
struct packing_data *mapping)
{
uint32_t i, num_objects;
uint32_t *reposition;
if (!bitmap_is_midx(bitmap_git))
load_reverse_index(bitmap_git);
else if (load_midx_revindex(bitmap_git->midx) < 0)
BUG("rebuild_existing_bitmaps: missing required rev-cache "
"extension");
num_objects = bitmap_num_objects(bitmap_git);
CALLOC_ARRAY(reposition, num_objects);
for (i = 0; i < num_objects; ++i) {
struct object_id oid;
struct object_entry *oe;
uint32_t index_pos;
if (bitmap_is_midx(bitmap_git))
index_pos = pack_pos_to_midx(bitmap_git->midx, i);
else
index_pos = pack_pos_to_index(bitmap_git->pack, i);
nth_bitmap_object_oid(bitmap_git, &oid, index_pos);
oe = packlist_find(mapping, &oid);
if (oe) {
reposition[i] = oe_in_pack_pos(mapping, oe) + 1;
if (bitmap_git->hashes && !oe->hash)
oe->hash = get_be32(bitmap_git->hashes + index_pos);
}
}
return reposition;
}
void free_bitmap_index(struct bitmap_index *b)
{
if (!b)
return;
if (b->map)
munmap(b->map, b->map_size);
ewah_pool_free(b->commits);
ewah_pool_free(b->trees);
ewah_pool_free(b->blobs);
ewah_pool_free(b->tags);
if (b->bitmaps) {
struct stored_bitmap *sb;
kh_foreach_value(b->bitmaps, sb, {
ewah_pool_free(sb->root);
free(sb);
});
}
kh_destroy_oid_map(b->bitmaps);
free(b->ext_index.objects);
free(b->ext_index.hashes);
kh_destroy_oid_pos(b->ext_index.positions);
bitmap_free(b->result);
bitmap_free(b->haves);
if (bitmap_is_midx(b)) {
/*
* Multi-pack bitmaps need to have resources associated with
* their on-disk reverse indexes unmapped so that stale .rev and
* .bitmap files can be removed.
*
* Unlike pack-based bitmaps, multi-pack bitmaps can be read and
* written in the same 'git multi-pack-index write --bitmap'
* process. Close resources so they can be removed safely on
* platforms like Windows.
*/
close_midx_revindex(b->midx);
}
free(b);
}
int bitmap_has_oid_in_uninteresting(struct bitmap_index *bitmap_git,
const struct object_id *oid)
{
return bitmap_git &&
bitmap_walk_contains(bitmap_git, bitmap_git->haves, oid);
}
static off_t get_disk_usage_for_type(struct bitmap_index *bitmap_git,
enum object_type object_type)
{
struct bitmap *result = bitmap_git->result;
off_t total = 0;
struct ewah_iterator it;
eword_t filter;
size_t i;
init_type_iterator(&it, bitmap_git, object_type);
for (i = 0; i < result->word_alloc &&
ewah_iterator_next(&filter, &it); i++) {
eword_t word = result->words[i] & filter;
size_t base = (i * BITS_IN_EWORD);
unsigned offset;
if (!word)
continue;
for (offset = 0; offset < BITS_IN_EWORD; offset++) {
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
if (bitmap_is_midx(bitmap_git)) {
uint32_t pack_pos;
uint32_t midx_pos = pack_pos_to_midx(bitmap_git->midx, base + offset);
off_t offset = nth_midxed_offset(bitmap_git->midx, midx_pos);
uint32_t pack_id = nth_midxed_pack_int_id(bitmap_git->midx, midx_pos);
struct packed_git *pack = bitmap_git->midx->packs[pack_id];
if (offset_to_pack_pos(pack, offset, &pack_pos) < 0) {
struct object_id oid;
nth_midxed_object_oid(&oid, bitmap_git->midx, midx_pos);
die(_("could not find '%s' in pack '%s' at offset %"PRIuMAX),
oid_to_hex(&oid),
pack->pack_name,
(uintmax_t)offset);
}
total += pack_pos_to_offset(pack, pack_pos + 1) - offset;
} else {
size_t pos = base + offset;
total += pack_pos_to_offset(bitmap_git->pack, pos + 1) -
pack_pos_to_offset(bitmap_git->pack, pos);
}
}
}
return total;
}
static off_t get_disk_usage_for_extended(struct bitmap_index *bitmap_git)
{
struct bitmap *result = bitmap_git->result;
struct eindex *eindex = &bitmap_git->ext_index;
off_t total = 0;
struct object_info oi = OBJECT_INFO_INIT;
off_t object_size;
size_t i;
oi.disk_sizep = &object_size;
for (i = 0; i < eindex->count; i++) {
struct object *obj = eindex->objects[i];
if (!bitmap_get(result, bitmap_num_objects(bitmap_git) + i))
continue;
if (oid_object_info_extended(the_repository, &obj->oid, &oi, 0) < 0)
die(_("unable to get disk usage of '%s'"),
oid_to_hex(&obj->oid));
total += object_size;
}
return total;
}
off_t get_disk_usage_from_bitmap(struct bitmap_index *bitmap_git,
struct rev_info *revs)
{
off_t total = 0;
total += get_disk_usage_for_type(bitmap_git, OBJ_COMMIT);
if (revs->tree_objects)
total += get_disk_usage_for_type(bitmap_git, OBJ_TREE);
if (revs->blob_objects)
total += get_disk_usage_for_type(bitmap_git, OBJ_BLOB);
if (revs->tag_objects)
total += get_disk_usage_for_type(bitmap_git, OBJ_TAG);
total += get_disk_usage_for_extended(bitmap_git);
return total;
}
int bitmap_is_midx(struct bitmap_index *bitmap_git)
{
return !!bitmap_git->midx;
}
const struct string_list *bitmap_preferred_tips(struct repository *r)
{
return repo_config_get_value_multi(r, "pack.preferbitmaptips");
}
int bitmap_is_preferred_refname(struct repository *r, const char *refname)
{
const struct string_list *preferred_tips = bitmap_preferred_tips(r);
struct string_list_item *item;
if (!preferred_tips)
return 0;
for_each_string_list_item(item, preferred_tips) {
if (starts_with(refname, item->string))
return 1;
}
return 0;
}