blob: 020c1774c8b474757a1c59c3af3c8b85cc037cd6 [file] [log] [blame]
#include "cache.h"
#include "object-store.h"
#include "commit.h"
#include "tag.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "progress.h"
#include "pack-revindex.h"
#include "pack.h"
#include "pack-bitmap.h"
#include "hash-lookup.h"
#include "pack-objects.h"
#include "commit-reach.h"
#include "prio-queue.h"
struct bitmapped_commit {
struct commit *commit;
struct ewah_bitmap *bitmap;
struct ewah_bitmap *write_as;
int flags;
int xor_offset;
uint32_t commit_pos;
};
struct bitmap_writer {
struct ewah_bitmap *commits;
struct ewah_bitmap *trees;
struct ewah_bitmap *blobs;
struct ewah_bitmap *tags;
kh_oid_map_t *bitmaps;
struct packing_data *to_pack;
struct bitmapped_commit *selected;
unsigned int selected_nr, selected_alloc;
struct progress *progress;
int show_progress;
unsigned char pack_checksum[GIT_MAX_RAWSZ];
};
static struct bitmap_writer writer;
void bitmap_writer_show_progress(int show)
{
writer.show_progress = show;
}
/**
* Build the initial type index for the packfile or multi-pack-index
*/
void bitmap_writer_build_type_index(struct packing_data *to_pack,
struct pack_idx_entry **index,
uint32_t index_nr)
{
uint32_t i;
writer.commits = ewah_new();
writer.trees = ewah_new();
writer.blobs = ewah_new();
writer.tags = ewah_new();
ALLOC_ARRAY(to_pack->in_pack_pos, to_pack->nr_objects);
for (i = 0; i < index_nr; ++i) {
struct object_entry *entry = (struct object_entry *)index[i];
enum object_type real_type;
oe_set_in_pack_pos(to_pack, entry, i);
switch (oe_type(entry)) {
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
real_type = oe_type(entry);
break;
default:
real_type = oid_object_info(to_pack->repo,
&entry->idx.oid, NULL);
break;
}
switch (real_type) {
case OBJ_COMMIT:
ewah_set(writer.commits, i);
break;
case OBJ_TREE:
ewah_set(writer.trees, i);
break;
case OBJ_BLOB:
ewah_set(writer.blobs, i);
break;
case OBJ_TAG:
ewah_set(writer.tags, i);
break;
default:
die("Missing type information for %s (%d/%d)",
oid_to_hex(&entry->idx.oid), real_type,
oe_type(entry));
}
}
}
/**
* Compute the actual bitmaps
*/
static inline void push_bitmapped_commit(struct commit *commit)
{
if (writer.selected_nr >= writer.selected_alloc) {
writer.selected_alloc = (writer.selected_alloc + 32) * 2;
REALLOC_ARRAY(writer.selected, writer.selected_alloc);
}
writer.selected[writer.selected_nr].commit = commit;
writer.selected[writer.selected_nr].bitmap = NULL;
writer.selected[writer.selected_nr].flags = 0;
writer.selected_nr++;
}
static uint32_t find_object_pos(const struct object_id *oid, int *found)
{
struct object_entry *entry = packlist_find(writer.to_pack, oid);
if (!entry) {
if (found)
*found = 0;
warning("Failed to write bitmap index. Packfile doesn't have full closure "
"(object %s is missing)", oid_to_hex(oid));
return 0;
}
if (found)
*found = 1;
return oe_in_pack_pos(writer.to_pack, entry);
}
static void compute_xor_offsets(void)
{
static const int MAX_XOR_OFFSET_SEARCH = 10;
int i, next = 0;
while (next < writer.selected_nr) {
struct bitmapped_commit *stored = &writer.selected[next];
int best_offset = 0;
struct ewah_bitmap *best_bitmap = stored->bitmap;
struct ewah_bitmap *test_xor;
for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
int curr = next - i;
if (curr < 0)
break;
test_xor = ewah_pool_new();
ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
if (test_xor->buffer_size < best_bitmap->buffer_size) {
if (best_bitmap != stored->bitmap)
ewah_pool_free(best_bitmap);
best_bitmap = test_xor;
best_offset = i;
} else {
ewah_pool_free(test_xor);
}
}
stored->xor_offset = best_offset;
stored->write_as = best_bitmap;
next++;
}
}
struct bb_commit {
struct commit_list *reverse_edges;
struct bitmap *commit_mask;
struct bitmap *bitmap;
unsigned selected:1,
maximal:1;
unsigned idx; /* within selected array */
};
define_commit_slab(bb_data, struct bb_commit);
struct bitmap_builder {
struct bb_data data;
struct commit **commits;
size_t commits_nr, commits_alloc;
};
static void bitmap_builder_init(struct bitmap_builder *bb,
struct bitmap_writer *writer,
struct bitmap_index *old_bitmap)
{
struct rev_info revs;
struct commit *commit;
struct commit_list *reusable = NULL;
struct commit_list *r;
unsigned int i, num_maximal = 0;
memset(bb, 0, sizeof(*bb));
init_bb_data(&bb->data);
reset_revision_walk();
repo_init_revisions(writer->to_pack->repo, &revs, NULL);
revs.topo_order = 1;
revs.first_parent_only = 1;
for (i = 0; i < writer->selected_nr; i++) {
struct commit *c = writer->selected[i].commit;
struct bb_commit *ent = bb_data_at(&bb->data, c);
ent->selected = 1;
ent->maximal = 1;
ent->idx = i;
ent->commit_mask = bitmap_new();
bitmap_set(ent->commit_mask, i);
add_pending_object(&revs, &c->object, "");
}
if (prepare_revision_walk(&revs))
die("revision walk setup failed");
while ((commit = get_revision(&revs))) {
struct commit_list *p = commit->parents;
struct bb_commit *c_ent;
parse_commit_or_die(commit);
c_ent = bb_data_at(&bb->data, commit);
/*
* If there is no commit_mask, there is no reason to iterate
* over this commit; it is not selected (if it were, it would
* not have a blank commit mask) and all its children have
* existing bitmaps (see the comment starting with "This commit
* has an existing bitmap" below), so it does not contribute
* anything to the final bitmap file or its descendants.
*/
if (!c_ent->commit_mask)
continue;
if (old_bitmap && bitmap_for_commit(old_bitmap, commit)) {
/*
* This commit has an existing bitmap, so we can
* get its bits immediately without an object
* walk. That is, it is reusable as-is and there is no
* need to continue walking beyond it.
*
* Mark it as such and add it to bb->commits separately
* to avoid allocating a position in the commit mask.
*/
commit_list_insert(commit, &reusable);
goto next;
}
if (c_ent->maximal) {
num_maximal++;
ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
bb->commits[bb->commits_nr++] = commit;
}
if (p) {
struct bb_commit *p_ent = bb_data_at(&bb->data, p->item);
int c_not_p, p_not_c;
if (!p_ent->commit_mask) {
p_ent->commit_mask = bitmap_new();
c_not_p = 1;
p_not_c = 0;
} else {
c_not_p = bitmap_is_subset(c_ent->commit_mask, p_ent->commit_mask);
p_not_c = bitmap_is_subset(p_ent->commit_mask, c_ent->commit_mask);
}
if (!c_not_p)
continue;
bitmap_or(p_ent->commit_mask, c_ent->commit_mask);
if (p_not_c)
p_ent->maximal = 1;
else {
p_ent->maximal = 0;
free_commit_list(p_ent->reverse_edges);
p_ent->reverse_edges = NULL;
}
if (c_ent->maximal) {
commit_list_insert(commit, &p_ent->reverse_edges);
} else {
struct commit_list *cc = c_ent->reverse_edges;
for (; cc; cc = cc->next) {
if (!commit_list_contains(cc->item, p_ent->reverse_edges))
commit_list_insert(cc->item, &p_ent->reverse_edges);
}
}
}
next:
bitmap_free(c_ent->commit_mask);
c_ent->commit_mask = NULL;
}
for (r = reusable; r; r = r->next) {
ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
bb->commits[bb->commits_nr++] = r->item;
}
trace2_data_intmax("pack-bitmap-write", the_repository,
"num_selected_commits", writer->selected_nr);
trace2_data_intmax("pack-bitmap-write", the_repository,
"num_maximal_commits", num_maximal);
free_commit_list(reusable);
}
static void bitmap_builder_clear(struct bitmap_builder *bb)
{
clear_bb_data(&bb->data);
free(bb->commits);
bb->commits_nr = bb->commits_alloc = 0;
}
static int fill_bitmap_tree(struct bitmap *bitmap,
struct tree *tree)
{
int found;
uint32_t pos;
struct tree_desc desc;
struct name_entry entry;
/*
* If our bit is already set, then there is nothing to do. Both this
* tree and all of its children will be set.
*/
pos = find_object_pos(&tree->object.oid, &found);
if (!found)
return -1;
if (bitmap_get(bitmap, pos))
return 0;
bitmap_set(bitmap, pos);
if (parse_tree(tree) < 0)
die("unable to load tree object %s",
oid_to_hex(&tree->object.oid));
init_tree_desc(&desc, tree->buffer, tree->size);
while (tree_entry(&desc, &entry)) {
switch (object_type(entry.mode)) {
case OBJ_TREE:
if (fill_bitmap_tree(bitmap,
lookup_tree(the_repository, &entry.oid)) < 0)
return -1;
break;
case OBJ_BLOB:
pos = find_object_pos(&entry.oid, &found);
if (!found)
return -1;
bitmap_set(bitmap, pos);
break;
default:
/* Gitlink, etc; not reachable */
break;
}
}
free_tree_buffer(tree);
return 0;
}
static int fill_bitmap_commit(struct bb_commit *ent,
struct commit *commit,
struct prio_queue *queue,
struct prio_queue *tree_queue,
struct bitmap_index *old_bitmap,
const uint32_t *mapping)
{
int found;
uint32_t pos;
if (!ent->bitmap)
ent->bitmap = bitmap_new();
prio_queue_put(queue, commit);
while (queue->nr) {
struct commit_list *p;
struct commit *c = prio_queue_get(queue);
if (old_bitmap && mapping) {
struct ewah_bitmap *old = bitmap_for_commit(old_bitmap, c);
/*
* If this commit has an old bitmap, then translate that
* bitmap and add its bits to this one. No need to walk
* parents or the tree for this commit.
*/
if (old && !rebuild_bitmap(mapping, old, ent->bitmap))
continue;
}
/*
* Mark ourselves and queue our tree. The commit
* walk ensures we cover all parents.
*/
pos = find_object_pos(&c->object.oid, &found);
if (!found)
return -1;
bitmap_set(ent->bitmap, pos);
prio_queue_put(tree_queue, get_commit_tree(c));
for (p = c->parents; p; p = p->next) {
pos = find_object_pos(&p->item->object.oid, &found);
if (!found)
return -1;
if (!bitmap_get(ent->bitmap, pos)) {
bitmap_set(ent->bitmap, pos);
prio_queue_put(queue, p->item);
}
}
}
while (tree_queue->nr) {
if (fill_bitmap_tree(ent->bitmap,
prio_queue_get(tree_queue)) < 0)
return -1;
}
return 0;
}
static void store_selected(struct bb_commit *ent, struct commit *commit)
{
struct bitmapped_commit *stored = &writer.selected[ent->idx];
khiter_t hash_pos;
int hash_ret;
stored->bitmap = bitmap_to_ewah(ent->bitmap);
hash_pos = kh_put_oid_map(writer.bitmaps, commit->object.oid, &hash_ret);
if (hash_ret == 0)
die("Duplicate entry when writing index: %s",
oid_to_hex(&commit->object.oid));
kh_value(writer.bitmaps, hash_pos) = stored;
}
int bitmap_writer_build(struct packing_data *to_pack)
{
struct bitmap_builder bb;
size_t i;
int nr_stored = 0; /* for progress */
struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
struct prio_queue tree_queue = { NULL };
struct bitmap_index *old_bitmap;
uint32_t *mapping;
int closed = 1; /* until proven otherwise */
writer.bitmaps = kh_init_oid_map();
writer.to_pack = to_pack;
if (writer.show_progress)
writer.progress = start_progress("Building bitmaps", writer.selected_nr);
trace2_region_enter("pack-bitmap-write", "building_bitmaps_total",
the_repository);
old_bitmap = prepare_bitmap_git(to_pack->repo);
if (old_bitmap)
mapping = create_bitmap_mapping(old_bitmap, to_pack);
else
mapping = NULL;
bitmap_builder_init(&bb, &writer, old_bitmap);
for (i = bb.commits_nr; i > 0; i--) {
struct commit *commit = bb.commits[i-1];
struct bb_commit *ent = bb_data_at(&bb.data, commit);
struct commit *child;
int reused = 0;
if (fill_bitmap_commit(ent, commit, &queue, &tree_queue,
old_bitmap, mapping) < 0) {
closed = 0;
break;
}
if (ent->selected) {
store_selected(ent, commit);
nr_stored++;
display_progress(writer.progress, nr_stored);
}
while ((child = pop_commit(&ent->reverse_edges))) {
struct bb_commit *child_ent =
bb_data_at(&bb.data, child);
if (child_ent->bitmap)
bitmap_or(child_ent->bitmap, ent->bitmap);
else if (reused)
child_ent->bitmap = bitmap_dup(ent->bitmap);
else {
child_ent->bitmap = ent->bitmap;
reused = 1;
}
}
if (!reused)
bitmap_free(ent->bitmap);
ent->bitmap = NULL;
}
clear_prio_queue(&queue);
clear_prio_queue(&tree_queue);
bitmap_builder_clear(&bb);
free_bitmap_index(old_bitmap);
free(mapping);
trace2_region_leave("pack-bitmap-write", "building_bitmaps_total",
the_repository);
stop_progress(&writer.progress);
if (closed)
compute_xor_offsets();
return closed;
}
/**
* Select the commits that will be bitmapped
*/
static inline unsigned int next_commit_index(unsigned int idx)
{
static const unsigned int MIN_COMMITS = 100;
static const unsigned int MAX_COMMITS = 5000;
static const unsigned int MUST_REGION = 100;
static const unsigned int MIN_REGION = 20000;
unsigned int offset, next;
if (idx <= MUST_REGION)
return 0;
if (idx <= MIN_REGION) {
offset = idx - MUST_REGION;
return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
}
offset = idx - MIN_REGION;
next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
return (next > MIN_COMMITS) ? next : MIN_COMMITS;
}
static int date_compare(const void *_a, const void *_b)
{
struct commit *a = *(struct commit **)_a;
struct commit *b = *(struct commit **)_b;
return (long)b->date - (long)a->date;
}
void bitmap_writer_select_commits(struct commit **indexed_commits,
unsigned int indexed_commits_nr,
int max_bitmaps)
{
unsigned int i = 0, j, next;
QSORT(indexed_commits, indexed_commits_nr, date_compare);
if (writer.show_progress)
writer.progress = start_progress("Selecting bitmap commits", 0);
if (indexed_commits_nr < 100) {
for (i = 0; i < indexed_commits_nr; ++i)
push_bitmapped_commit(indexed_commits[i]);
return;
}
for (;;) {
struct commit *chosen = NULL;
next = next_commit_index(i);
if (i + next >= indexed_commits_nr)
break;
if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
writer.selected_nr = max_bitmaps;
break;
}
if (next == 0) {
chosen = indexed_commits[i];
} else {
chosen = indexed_commits[i + next];
for (j = 0; j <= next; ++j) {
struct commit *cm = indexed_commits[i + j];
if ((cm->object.flags & NEEDS_BITMAP) != 0) {
chosen = cm;
break;
}
if (cm->parents && cm->parents->next)
chosen = cm;
}
}
push_bitmapped_commit(chosen);
i += next + 1;
display_progress(writer.progress, i);
}
stop_progress(&writer.progress);
}
static int hashwrite_ewah_helper(void *f, const void *buf, size_t len)
{
/* hashwrite will die on error */
hashwrite(f, buf, len);
return len;
}
/**
* Write the bitmap index to disk
*/
static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
{
if (ewah_serialize_to(bitmap, hashwrite_ewah_helper, f) < 0)
die("Failed to write bitmap index");
}
static const struct object_id *oid_access(size_t pos, const void *table)
{
const struct pack_idx_entry * const *index = table;
return &index[pos]->oid;
}
static void write_selected_commits_v1(struct hashfile *f,
struct pack_idx_entry **index,
uint32_t index_nr)
{
int i;
for (i = 0; i < writer.selected_nr; ++i) {
struct bitmapped_commit *stored = &writer.selected[i];
int commit_pos =
oid_pos(&stored->commit->object.oid, index, index_nr, oid_access);
if (commit_pos < 0)
BUG("trying to write commit not in index");
hashwrite_be32(f, commit_pos);
hashwrite_u8(f, stored->xor_offset);
hashwrite_u8(f, stored->flags);
dump_bitmap(f, stored->write_as);
}
}
static void write_hash_cache(struct hashfile *f,
struct pack_idx_entry **index,
uint32_t index_nr)
{
uint32_t i;
for (i = 0; i < index_nr; ++i) {
struct object_entry *entry = (struct object_entry *)index[i];
hashwrite_be32(f, entry->hash);
}
}
void bitmap_writer_set_checksum(unsigned char *sha1)
{
hashcpy(writer.pack_checksum, sha1);
}
void bitmap_writer_finish(struct pack_idx_entry **index,
uint32_t index_nr,
const char *filename,
uint16_t options)
{
static uint16_t default_version = 1;
static uint16_t flags = BITMAP_OPT_FULL_DAG;
struct strbuf tmp_file = STRBUF_INIT;
struct hashfile *f;
struct bitmap_disk_header header;
int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
f = hashfd(fd, tmp_file.buf);
memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
header.version = htons(default_version);
header.options = htons(flags | options);
header.entry_count = htonl(writer.selected_nr);
hashcpy(header.checksum, writer.pack_checksum);
hashwrite(f, &header, sizeof(header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz);
dump_bitmap(f, writer.commits);
dump_bitmap(f, writer.trees);
dump_bitmap(f, writer.blobs);
dump_bitmap(f, writer.tags);
write_selected_commits_v1(f, index, index_nr);
if (options & BITMAP_OPT_HASH_CACHE)
write_hash_cache(f, index, index_nr);
finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
if (adjust_shared_perm(tmp_file.buf))
die_errno("unable to make temporary bitmap file readable");
if (rename(tmp_file.buf, filename))
die_errno("unable to rename temporary bitmap file to '%s'", filename);
strbuf_release(&tmp_file);
}