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git/pack-bitmap.c
Junio C Hamano e8e71848ea Merge branch 'jk/nth-packed-object-id'
Code cleanup to use "struct object_id" more by replacing use of
"char *sha1"

* jk/nth-packed-object-id:
  packfile: drop nth_packed_object_sha1()
  packed_object_info(): use object_id internally for delta base
  packed_object_info(): use object_id for returning delta base
  pack-check: push oid lookup into loop
  pack-check: convert "internal error" die to a BUG()
  pack-bitmap: use object_id when loading on-disk bitmaps
  pack-objects: use object_id struct in pack-reuse code
  pack-objects: convert oe_set_delta_ext() to use object_id
  pack-objects: read delta base oid into object_id struct
  nth_packed_object_oid(): use customary integer return
2020-03-05 10:43:03 -08:00

1405 lines
34 KiB
C

#include "cache.h"
#include "commit.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"
/*
* 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 {
/* Packfile to which this bitmap index belongs to */
struct packed_git *pack;
/*
* 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;
/*
* 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 == NULL)
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 int load_bitmap_header(struct bitmap_index *index)
{
struct bitmap_disk_header *header = (void *)index->map;
if (index->map_size < sizeof(*header) + the_hash_algo->rawsz)
return error("Corrupted bitmap index (missing header data)");
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 for bitmap index file (%d)", index->version);
/* Parse known bitmap format options */
{
uint32_t flags = ntohs(header->options);
if ((flags & BITMAP_OPT_FULL_DAG) == 0)
return error("Unsupported options for bitmap index file "
"(Git requires BITMAP_OPT_FULL_DAG)");
if (flags & BITMAP_OPT_HASH_CACHE) {
unsigned char *end = index->map + index->map_size - the_hash_algo->rawsz;
index->hashes = ((uint32_t *)end) - index->pack->num_objects;
}
}
index->entry_count = ntohl(header->entry_count);
index->map_pos += sizeof(*header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz;
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 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;
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);
nth_packed_object_id(&oid, index->pack, 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 == NULL)
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;
}
static 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_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git *packfile)
{
int fd;
struct stat st;
char *idx_name;
if (open_pack_index(packfile))
return -1;
idx_name = pack_bitmap_filename(packfile);
fd = git_open(idx_name);
free(idx_name);
if (fd < 0)
return -1;
if (fstat(fd, &st)) {
close(fd);
return -1;
}
if (bitmap_git->pack) {
warning("ignoring extra bitmap file: %s", packfile->pack_name);
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;
return -1;
}
return 0;
}
static int load_pack_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_pack_revindex(bitmap_git->pack))
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 (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;
assert(!bitmap_git->map);
for (p = get_all_packs(r); p; p = p->next) {
if (open_pack_bitmap_1(bitmap_git, p) == 0)
ret = 0;
}
return ret;
}
struct bitmap_index *prepare_bitmap_git(struct repository *r)
{
struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
if (!open_pack_bitmap(r, bitmap_git) && !load_pack_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;
};
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_git->pack->num_objects;
}
return -1;
}
static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git,
const struct object_id *oid)
{
off_t offset = find_pack_entry_one(oid->hash, bitmap_git->pack);
if (!offset)
return -1;
return find_revindex_position(bitmap_git->pack, offset);
}
static int bitmap_position(struct bitmap_index *bitmap_git,
const struct object_id *oid)
{
int 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_git->pack->num_objects;
}
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, void *data)
{
}
static int add_to_include_set(struct bitmap_index *bitmap_git,
struct include_data *data,
const struct object_id *oid,
int bitmap_pos)
{
khiter_t hash_pos;
if (data->seen && bitmap_get(data->seen, bitmap_pos))
return 0;
if (bitmap_get(data->base, bitmap_pos))
return 0;
hash_pos = kh_get_oid_map(bitmap_git->bitmaps, *oid);
if (hash_pos < kh_end(bitmap_git->bitmaps)) {
struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, hash_pos);
bitmap_or_ewah(data->base, lookup_stored_bitmap(st));
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->object.oid,
bitmap_pos)) {
struct commit_list *parent = commit->parents;
while (parent) {
parent->item->object.flags |= SEEN;
parent = parent->next;
}
return 0;
}
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) {
khiter_t pos = kh_get_oid_map(bitmap_git->bitmaps, object->oid);
if (pos < kh_end(bitmap_git->bitmaps)) {
struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
struct ewah_bitmap *or_with = lookup_stored_bitmap(st);
if (base == NULL)
base = ewah_to_bitmap(or_with);
else
bitmap_or_ewah(base, or_with);
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 == NULL)
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 == NULL)
base = bitmap_new();
incdata.bitmap_git = bitmap_git;
incdata.base = base;
incdata.seen = seen;
revs->include_check = should_include;
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);
}
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_git->pack->num_objects + 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 object_id oid;
struct revindex_entry *entry;
uint32_t hash = 0;
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
entry = &bitmap_git->pack->revindex[pos + offset];
nth_packed_object_id(&oid, bitmap_git->pack, entry->nr);
if (bitmap_git->hashes)
hash = get_be32(bitmap_git->hashes + entry->nr);
show_reach(&oid, object_type, 0, hash, bitmap_git->pack, entry->offset);
}
}
}
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 (find_pack_entry_one(object->oid.hash, bitmap_git->pack) > 0)
return 1;
}
return 0;
}
static struct bitmap *find_tip_blobs(struct bitmap_index *bitmap_git,
struct object_list *tip_objects)
{
struct bitmap *result = bitmap_new();
struct object_list *p;
for (p = tip_objects; p; p = p->next) {
int pos;
if (p->item->type != OBJ_BLOB)
continue;
pos = bitmap_position(bitmap_git, &p->item->oid);
if (pos < 0)
continue;
bitmap_set(result, pos);
}
return result;
}
static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
struct object_list *tip_objects,
struct bitmap *to_filter)
{
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
* blobs which the other side specifically asked for,
* so we must match that behavior.
*/
tips = find_tip_blobs(bitmap_git, tip_objects);
/*
* We can use the blob type-bitmap to work in whole words
* for the objects that are actually in the bitmapped packfile.
*/
for (i = 0, init_type_iterator(&it, bitmap_git, OBJ_BLOB);
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 blobs 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_git->pack->num_objects;
if (eindex->objects[i]->type == OBJ_BLOB &&
bitmap_get(to_filter, pos) &&
!bitmap_get(tips, pos))
bitmap_unset(to_filter, pos);
}
bitmap_free(tips);
}
static unsigned long get_size_by_pos(struct bitmap_index *bitmap_git,
uint32_t pos)
{
struct packed_git *pack = bitmap_git->pack;
unsigned long size;
struct object_info oi = OBJECT_INFO_INIT;
oi.sizep = &size;
if (pos < pack->num_objects) {
struct revindex_entry *entry = &pack->revindex[pos];
if (packed_object_info(the_repository, pack,
entry->offset, &oi) < 0) {
struct object_id oid;
nth_packed_object_id(&oid, pack, entry->nr);
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 - pack->num_objects];
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_blobs(bitmap_git, tip_objects);
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_git->pack->num_objects;
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 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;
}
/* 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,
struct list_objects_filter_options *filter)
{
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(filter))
return NULL;
/* try to open a bitmapped pack, but don't parse it yet
* because we may not need to use it */
bitmap_git = xcalloc(1, sizeof(*bitmap_git));
if (open_pack_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);
}
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_pack_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 == NULL)
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, wants, wants_bitmap, 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;
}
static void try_partial_reuse(struct bitmap_index *bitmap_git,
size_t pos,
struct bitmap *reuse,
struct pack_window **w_curs)
{
struct revindex_entry *revidx;
off_t offset;
enum object_type type;
unsigned long size;
if (pos >= bitmap_git->pack->num_objects)
return; /* not actually in the pack */
revidx = &bitmap_git->pack->revindex[pos];
offset = revidx->offset;
type = unpack_object_header(bitmap_git->pack, w_curs, &offset, &size);
if (type < 0)
return; /* broken packfile, punt */
if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA) {
off_t base_offset;
int 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(bitmap_git->pack, w_curs,
&offset, type, revidx->offset);
if (!base_offset)
return;
base_pos = find_revindex_position(bitmap_git->pack, base_offset);
if (base_pos < 0)
return;
/*
* 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;
/*
* 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;
}
/*
* If we got here, then the object is OK to reuse. Mark it.
*/
bitmap_set(reuse, pos);
}
int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
struct packed_git **packfile_out,
uint32_t *entries,
struct bitmap **reuse_out)
{
struct bitmap *result = bitmap_git->result;
struct bitmap *reuse;
struct pack_window *w_curs = NULL;
size_t i = 0;
uint32_t offset;
assert(result);
while (i < result->word_alloc && result->words[i] == (eword_t)~0)
i++;
/* Don't mark objects not in the packfile */
if (i > bitmap_git->pack->num_objects / BITS_IN_EWORD)
i = bitmap_git->pack->num_objects / 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);
try_partial_reuse(bitmap_git, pos + offset, reuse, &w_curs);
}
}
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 = bitmap_git->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_git->pack->num_objects + 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 progress *prg;
size_t seen;
};
static void test_show_object(struct object *object, const char *name,
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\n", oid_to_hex(&object->oid));
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\n", oid_to_hex(&commit->object.oid));
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;
khiter_t pos;
size_t result_popcnt;
struct bitmap_test_data tdata;
struct bitmap_index *bitmap_git;
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(stderr, "Bitmap v%d test (%d entries loaded)\n",
bitmap_git->version, bitmap_git->entry_count);
root = revs->pending.objects[0].item;
pos = kh_get_oid_map(bitmap_git->bitmaps, root->oid);
if (pos < kh_end(bitmap_git->bitmaps)) {
struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
struct ewah_bitmap *bm = lookup_stored_bitmap(st);
fprintf(stderr, "Found bitmap for %s. %d bits / %08x checksum\n",
oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm));
result = ewah_to_bitmap(bm);
}
if (result == NULL)
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.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(stderr, "OK!\n");
else
fprintf(stderr, "Mismatch!\n");
free_bitmap_index(bitmap_git);
}
static int rebuild_bitmap(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;
}
int rebuild_existing_bitmaps(struct bitmap_index *bitmap_git,
struct packing_data *mapping,
kh_oid_map_t *reused_bitmaps,
int show_progress)
{
uint32_t i, num_objects;
uint32_t *reposition;
struct bitmap *rebuild;
struct stored_bitmap *stored;
struct progress *progress = NULL;
khiter_t hash_pos;
int hash_ret;
num_objects = bitmap_git->pack->num_objects;
reposition = xcalloc(num_objects, sizeof(uint32_t));
for (i = 0; i < num_objects; ++i) {
struct object_id oid;
struct revindex_entry *entry;
struct object_entry *oe;
entry = &bitmap_git->pack->revindex[i];
nth_packed_object_id(&oid, bitmap_git->pack, entry->nr);
oe = packlist_find(mapping, &oid);
if (oe)
reposition[i] = oe_in_pack_pos(mapping, oe) + 1;
}
rebuild = bitmap_new();
i = 0;
if (show_progress)
progress = start_progress("Reusing bitmaps", 0);
kh_foreach_value(bitmap_git->bitmaps, stored, {
if (stored->flags & BITMAP_FLAG_REUSE) {
if (!rebuild_bitmap(reposition,
lookup_stored_bitmap(stored),
rebuild)) {
hash_pos = kh_put_oid_map(reused_bitmaps,
stored->oid,
&hash_ret);
kh_value(reused_bitmaps, hash_pos) =
bitmap_to_ewah(rebuild);
}
bitmap_reset(rebuild);
display_progress(progress, ++i);
}
});
stop_progress(&progress);
free(reposition);
bitmap_free(rebuild);
return 0;
}
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);
kh_destroy_oid_map(b->bitmaps);
free(b->ext_index.objects);
free(b->ext_index.hashes);
bitmap_free(b->result);
bitmap_free(b->haves);
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);
}