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git/pack-bitmap-write.c

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#define USE_THE_REPOSITORY_VARIABLE
#include "git-compat-util.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "object-store-ll.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "progress.h"
#include "pack.h"
#include "pack-bitmap.h"
#include "hash-lookup.h"
#include "pack-objects.h"
#include "path.h"
#include "commit-reach.h"
#include "prio-queue.h"
#include "trace2.h"
#include "tree.h"
#include "tree-walk.h"
#include "pseudo-merge.h"
#include "oid-array.h"
#include "config.h"
#include "alloc.h"
#include "refs.h"
#include "strmap.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;
unsigned pseudo_merge : 1;
};
static inline int bitmap_writer_nr_selected_commits(struct bitmap_writer *writer)
{
return writer->selected_nr - writer->pseudo_merges_nr;
}
void bitmap_writer_init(struct bitmap_writer *writer, struct repository *r,
struct packing_data *pdata)
{
memset(writer, 0, sizeof(struct bitmap_writer));
if (writer->bitmaps)
BUG("bitmap writer already initialized");
writer->bitmaps = kh_init_oid_map();
writer->pseudo_merge_commits = kh_init_oid_map();
writer->to_pack = pdata;
string_list_init_dup(&writer->pseudo_merge_groups);
load_pseudo_merges_from_config(r, &writer->pseudo_merge_groups);
}
static void free_pseudo_merge_commit_idx(struct pseudo_merge_commit_idx *idx)
{
if (!idx)
return;
free(idx->pseudo_merge);
free(idx);
}
void bitmap_writer_free(struct bitmap_writer *writer)
{
uint32_t i;
struct pseudo_merge_commit_idx *idx;
if (!writer)
return;
ewah_free(writer->commits);
ewah_free(writer->trees);
ewah_free(writer->blobs);
ewah_free(writer->tags);
kh_destroy_oid_map(writer->bitmaps);
kh_foreach_value(writer->pseudo_merge_commits, idx,
free_pseudo_merge_commit_idx(idx));
kh_destroy_oid_map(writer->pseudo_merge_commits);
for (i = 0; i < writer->selected_nr; i++) {
struct bitmapped_commit *bc = &writer->selected[i];
if (bc->write_as != bc->bitmap)
ewah_free(bc->write_as);
ewah_free(bc->bitmap);
}
free(writer->selected);
}
void bitmap_writer_show_progress(struct bitmap_writer *writer, 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 bitmap_writer *writer,
struct pack_idx_entry **index)
{
uint32_t i;
writer->commits = ewah_new();
writer->trees = ewah_new();
writer->blobs = ewah_new();
writer->tags = ewah_new();
ALLOC_ARRAY(writer->to_pack->in_pack_pos, writer->to_pack->nr_objects);
for (i = 0; i < writer->to_pack->nr_objects; ++i) {
struct object_entry *entry = (struct object_entry *)index[i];
enum object_type real_type;
oe_set_in_pack_pos(writer->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(writer->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));
}
}
}
int bitmap_writer_has_bitmapped_object_id(struct bitmap_writer *writer,
const struct object_id *oid)
{
return kh_get_oid_map(writer->bitmaps, *oid) != kh_end(writer->bitmaps);
}
/**
* Compute the actual bitmaps
*/
void bitmap_writer_push_commit(struct bitmap_writer *writer,
struct commit *commit, unsigned pseudo_merge)
{
if (writer->selected_nr >= writer->selected_alloc) {
writer->selected_alloc = (writer->selected_alloc + 32) * 2;
REALLOC_ARRAY(writer->selected, writer->selected_alloc);
}
if (!pseudo_merge) {
int hash_ret;
khiter_t hash_pos = kh_put_oid_map(writer->bitmaps,
commit->object.oid,
&hash_ret);
if (!hash_ret)
die(_("duplicate entry when writing bitmap index: %s"),
oid_to_hex(&commit->object.oid));
kh_value(writer->bitmaps, hash_pos) = NULL;
}
writer->selected[writer->selected_nr].commit = commit;
writer->selected[writer->selected_nr].bitmap = NULL;
writer->selected[writer->selected_nr].write_as = NULL;
writer->selected[writer->selected_nr].flags = 0;
writer->selected[writer->selected_nr].pseudo_merge = pseudo_merge;
writer->selected_nr++;
}
static uint32_t find_object_pos(struct bitmap_writer *writer,
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(struct bitmap_writer *writer)
{
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;
if (stored->pseudo_merge)
goto next;
for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
int curr = next - i;
if (curr < 0)
break;
if (writer->selected[curr].pseudo_merge)
continue;
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);
}
}
next:
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,
pseudo_merge:1;
unsigned idx; /* within selected array */
};
static void clear_bb_commit(struct bb_commit *commit)
{
free_commit_list(commit->reverse_edges);
bitmap_free(commit->commit_mask);
bitmap_free(commit->bitmap);
}
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 bitmapped_commit *bc = &writer->selected[i];
struct bb_commit *ent = bb_data_at(&bb->data, bc->commit);
ent->selected = 1;
ent->maximal = 1;
ent->pseudo_merge = bc->pseudo_merge;
ent->idx = i;
ent->commit_mask = bitmap_new();
bitmap_set(ent->commit_mask, i);
add_pending_object(&revs, &bc->commit->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);
release_revisions(&revs);
free_commit_list(reusable);
}
static void bitmap_builder_clear(struct bitmap_builder *bb)
{
deep_clear_bb_data(&bb->data, clear_bb_commit);
free(bb->commits);
bb->commits_nr = bb->commits_alloc = 0;
}
static int fill_bitmap_tree(struct bitmap_writer *writer,
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(writer, &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->object.oid, tree->buffer, tree->size);
while (tree_entry(&desc, &entry)) {
switch (object_type(entry.mode)) {
case OBJ_TREE:
if (fill_bitmap_tree(writer, bitmap,
lookup_tree(the_repository, &entry.oid)) < 0)
return -1;
break;
case OBJ_BLOB:
pos = find_object_pos(writer, &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 reused_bitmaps_nr;
static int reused_pseudo_merge_bitmaps_nr;
static int fill_bitmap_commit(struct bitmap_writer *writer,
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;
struct bitmap *remapped = bitmap_new();
if (commit->object.flags & BITMAP_PSEUDO_MERGE)
old = pseudo_merge_bitmap_for_commit(old_bitmap, c);
else
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, remapped)) {
bitmap_or(ent->bitmap, remapped);
bitmap_free(remapped);
if (commit->object.flags & BITMAP_PSEUDO_MERGE)
reused_pseudo_merge_bitmaps_nr++;
else
reused_bitmaps_nr++;
continue;
}
bitmap_free(remapped);
}
/*
* Mark ourselves and queue our tree. The commit
* walk ensures we cover all parents.
*/
if (!(c->object.flags & BITMAP_PSEUDO_MERGE)) {
pos = find_object_pos(writer, &c->object.oid, &found);
if (!found)
return -1;
bitmap_set(ent->bitmap, pos);
prio_queue_put(tree_queue,
repo_get_commit_tree(the_repository, c));
}
for (p = c->parents; p; p = p->next) {
pos = find_object_pos(writer, &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(writer, ent->bitmap,
prio_queue_get(tree_queue)) < 0)
return -1;
}
return 0;
}
static void store_selected(struct bitmap_writer *writer,
struct bb_commit *ent, struct commit *commit)
{
struct bitmapped_commit *stored = &writer->selected[ent->idx];
khiter_t hash_pos;
stored->bitmap = bitmap_to_ewah(ent->bitmap);
if (ent->pseudo_merge)
return;
hash_pos = kh_get_oid_map(writer->bitmaps, commit->object.oid);
if (hash_pos == kh_end(writer->bitmaps))
die(_("attempted to store non-selected commit: '%s'"),
oid_to_hex(&commit->object.oid));
kh_value(writer->bitmaps, hash_pos) = stored;
}
int bitmap_writer_build(struct bitmap_writer *writer)
{
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 */
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(writer->to_pack->repo);
if (old_bitmap)
mapping = create_bitmap_mapping(old_bitmap, writer->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(writer, ent, commit, &queue, &tree_queue,
old_bitmap, mapping) < 0) {
closed = 0;
break;
}
if (ent->selected) {
store_selected(writer, 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);
trace2_data_intmax("pack-bitmap-write", the_repository,
"building_bitmaps_reused", reused_bitmaps_nr);
trace2_data_intmax("pack-bitmap-write", the_repository,
"building_bitmaps_pseudo_merge_reused",
reused_pseudo_merge_bitmaps_nr);
stop_progress(&writer->progress);
if (closed)
compute_xor_offsets(writer);
return closed ? 0 : -1;
}
/**
* 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 bitmap_writer *writer,
struct commit **indexed_commits,
unsigned int indexed_commits_nr)
{
unsigned int i = 0, j, next;
QSORT(indexed_commits, indexed_commits_nr, date_compare);
if (indexed_commits_nr < 100) {
for (i = 0; i < indexed_commits_nr; ++i)
bitmap_writer_push_commit(writer, indexed_commits[i], 0);
select_pseudo_merges(writer);
return;
}
if (writer->show_progress)
writer->progress = start_progress("Selecting bitmap commits", 0);
for (;;) {
struct commit *chosen = NULL;
next = next_commit_index(i);
if (i + next >= indexed_commits_nr)
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;
}
}
bitmap_writer_push_commit(writer, chosen, 0);
i += next + 1;
display_progress(writer->progress, i);
}
stop_progress(&writer->progress);
select_pseudo_merges(writer);
}
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 bitmap_writer *writer,
struct hashfile *f, off_t *offsets)
{
int i;
for (i = 0; i < bitmap_writer_nr_selected_commits(writer); ++i) {
struct bitmapped_commit *stored = &writer->selected[i];
if (stored->pseudo_merge)
BUG("unexpected pseudo-merge among selected: %s",
oid_to_hex(&stored->commit->object.oid));
if (offsets)
offsets[i] = hashfile_total(f);
hashwrite_be32(f, stored->commit_pos);
hashwrite_u8(f, stored->xor_offset);
hashwrite_u8(f, stored->flags);
dump_bitmap(f, stored->write_as);
}
}
static void write_pseudo_merges(struct bitmap_writer *writer,
struct hashfile *f)
{
struct oid_array commits = OID_ARRAY_INIT;
struct bitmap **commits_bitmap = NULL;
off_t *pseudo_merge_ofs = NULL;
off_t start, table_start, next_ext;
uint32_t base = bitmap_writer_nr_selected_commits(writer);
size_t i, j = 0;
CALLOC_ARRAY(commits_bitmap, writer->pseudo_merges_nr);
CALLOC_ARRAY(pseudo_merge_ofs, writer->pseudo_merges_nr);
for (i = 0; i < writer->pseudo_merges_nr; i++) {
struct bitmapped_commit *merge = &writer->selected[base + i];
struct commit_list *p;
if (!merge->pseudo_merge)
BUG("found non-pseudo merge commit at %"PRIuMAX, (uintmax_t)i);
commits_bitmap[i] = bitmap_new();
for (p = merge->commit->parents; p; p = p->next)
bitmap_set(commits_bitmap[i],
find_object_pos(writer, &p->item->object.oid,
NULL));
}
start = hashfile_total(f);
for (i = 0; i < writer->pseudo_merges_nr; i++) {
struct ewah_bitmap *commits_ewah = bitmap_to_ewah(commits_bitmap[i]);
pseudo_merge_ofs[i] = hashfile_total(f);
dump_bitmap(f, commits_ewah);
dump_bitmap(f, writer->selected[base+i].write_as);
ewah_free(commits_ewah);
}
next_ext = st_add(hashfile_total(f),
st_mult(kh_size(writer->pseudo_merge_commits),
sizeof(uint64_t)));
table_start = hashfile_total(f);
commits.alloc = kh_size(writer->pseudo_merge_commits);
CALLOC_ARRAY(commits.oid, commits.alloc);
for (i = kh_begin(writer->pseudo_merge_commits); i != kh_end(writer->pseudo_merge_commits); i++) {
if (!kh_exist(writer->pseudo_merge_commits, i))
continue;
oid_array_append(&commits, &kh_key(writer->pseudo_merge_commits, i));
}
oid_array_sort(&commits);
/* write lookup table (non-extended) */
for (i = 0; i < commits.nr; i++) {
int hash_pos;
struct pseudo_merge_commit_idx *c;
hash_pos = kh_get_oid_map(writer->pseudo_merge_commits,
commits.oid[i]);
if (hash_pos == kh_end(writer->pseudo_merge_commits))
BUG("could not find pseudo-merge commit %s",
oid_to_hex(&commits.oid[i]));
c = kh_value(writer->pseudo_merge_commits, hash_pos);
hashwrite_be32(f, find_object_pos(writer, &commits.oid[i],
NULL));
if (c->nr == 1)
hashwrite_be64(f, pseudo_merge_ofs[c->pseudo_merge[0]]);
else if (c->nr > 1) {
if (next_ext & ((uint64_t)1<<63))
die(_("too many pseudo-merges"));
hashwrite_be64(f, next_ext | ((uint64_t)1<<63));
next_ext = st_add3(next_ext,
sizeof(uint32_t),
st_mult(c->nr, sizeof(uint64_t)));
} else
BUG("expected commit '%s' to have at least one "
"pseudo-merge", oid_to_hex(&commits.oid[i]));
}
/* write lookup table (extended) */
for (i = 0; i < commits.nr; i++) {
int hash_pos;
struct pseudo_merge_commit_idx *c;
hash_pos = kh_get_oid_map(writer->pseudo_merge_commits,
commits.oid[i]);
if (hash_pos == kh_end(writer->pseudo_merge_commits))
BUG("could not find pseudo-merge commit %s",
oid_to_hex(&commits.oid[i]));
c = kh_value(writer->pseudo_merge_commits, hash_pos);
if (c->nr == 1)
continue;
hashwrite_be32(f, c->nr);
for (j = 0; j < c->nr; j++)
hashwrite_be64(f, pseudo_merge_ofs[c->pseudo_merge[j]]);
}
/* write positions for all pseudo merges */
for (i = 0; i < writer->pseudo_merges_nr; i++)
hashwrite_be64(f, pseudo_merge_ofs[i]);
hashwrite_be32(f, writer->pseudo_merges_nr);
hashwrite_be32(f, kh_size(writer->pseudo_merge_commits));
hashwrite_be64(f, table_start - start);
hashwrite_be64(f, hashfile_total(f) - start + sizeof(uint64_t));
for (i = 0; i < writer->pseudo_merges_nr; i++)
bitmap_free(commits_bitmap[i]);
free(pseudo_merge_ofs);
free(commits_bitmap);
}
static int table_cmp(const void *_va, const void *_vb, void *_data)
{
struct bitmap_writer *writer = _data;
struct bitmapped_commit *a = &writer->selected[*(uint32_t *)_va];
struct bitmapped_commit *b = &writer->selected[*(uint32_t *)_vb];
if (a->commit_pos < b->commit_pos)
return -1;
else if (a->commit_pos > b->commit_pos)
return 1;
return 0;
}
static void write_lookup_table(struct bitmap_writer *writer, struct hashfile *f,
off_t *offsets)
{
uint32_t i;
uint32_t *table, *table_inv;
ALLOC_ARRAY(table, bitmap_writer_nr_selected_commits(writer));
ALLOC_ARRAY(table_inv, bitmap_writer_nr_selected_commits(writer));
for (i = 0; i < bitmap_writer_nr_selected_commits(writer); i++)
table[i] = i;
/*
* At the end of this sort table[j] = i means that the i'th
* bitmap corresponds to j'th bitmapped commit (among the selected
* commits) in lex order of OIDs.
*/
QSORT_S(table, bitmap_writer_nr_selected_commits(writer), table_cmp, writer);
/* table_inv helps us discover that relationship (i'th bitmap
* to j'th commit by j = table_inv[i])
*/
for (i = 0; i < bitmap_writer_nr_selected_commits(writer); i++)
table_inv[table[i]] = i;
trace2_region_enter("pack-bitmap-write", "writing_lookup_table", the_repository);
for (i = 0; i < bitmap_writer_nr_selected_commits(writer); i++) {
struct bitmapped_commit *selected = &writer->selected[table[i]];
uint32_t xor_offset = selected->xor_offset;
uint32_t xor_row;
if (xor_offset) {
/*
* xor_index stores the index (in the bitmap entries)
* of the corresponding xor bitmap. But we need to convert
* this index into lookup table's index. So, table_inv[xor_index]
* gives us the index position w.r.t. the lookup table.
*
* If "k = table[i] - xor_offset" then the xor base is the k'th
* bitmap. `table_inv[k]` gives us the position of that bitmap
* in the lookup table.
*/
uint32_t xor_index = table[i] - xor_offset;
xor_row = table_inv[xor_index];
} else {
xor_row = 0xffffffff;
}
hashwrite_be32(f, writer->selected[table[i]].commit_pos);
hashwrite_be64(f, (uint64_t)offsets[table[i]]);
hashwrite_be32(f, xor_row);
}
trace2_region_leave("pack-bitmap-write", "writing_lookup_table", the_repository);
free(table);
free(table_inv);
}
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(struct bitmap_writer *writer,
const unsigned char *sha1)
{
hashcpy(writer->pack_checksum, sha1, the_repository->hash_algo);
}
void bitmap_writer_finish(struct bitmap_writer *writer,
struct pack_idx_entry **index,
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;
off_t *offsets = NULL;
uint32_t i;
struct bitmap_disk_header header;
int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
if (writer->pseudo_merges_nr)
options |= BITMAP_OPT_PSEUDO_MERGES;
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(bitmap_writer_nr_selected_commits(writer));
hashcpy(header.checksum, writer->pack_checksum, the_repository->hash_algo);
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);
if (options & BITMAP_OPT_LOOKUP_TABLE)
CALLOC_ARRAY(offsets, writer->to_pack->nr_objects);
for (i = 0; i < bitmap_writer_nr_selected_commits(writer); i++) {
struct bitmapped_commit *stored = &writer->selected[i];
int commit_pos = oid_pos(&stored->commit->object.oid, index,
writer->to_pack->nr_objects,
oid_access);
if (commit_pos < 0)
BUG(_("trying to write commit not in index"));
stored->commit_pos = commit_pos;
}
write_selected_commits_v1(writer, f, offsets);
if (options & BITMAP_OPT_PSEUDO_MERGES)
write_pseudo_merges(writer, f);
if (options & BITMAP_OPT_LOOKUP_TABLE)
write_lookup_table(writer, f, offsets);
if (options & BITMAP_OPT_HASH_CACHE)
write_hash_cache(f, index, writer->to_pack->nr_objects);
finalize_hashfile(f, NULL, FSYNC_COMPONENT_PACK_METADATA,
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);
free(offsets);
}
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