git/delta-islands.c
Jeff King fe299ec5ae oid_array: rename source file from sha1-array
We renamed the actual data structure in 910650d2f8 (Rename sha1_array to
oid_array, 2017-03-31), but the file is still called sha1-array. Besides
being slightly confusing, it makes it more annoying to grep for leftover
occurrences of "sha1" in various files, because the header is included
in so many places.

Let's complete the transition by renaming the source and header files
(and fixing up a few comment references).

I kept the "-" in the name, as that seems to be our style; cf.
fc1395f4a4 (sha1_file.c: rename to use dash in file name, 2018-04-10).
We also have oidmap.h and oidset.h without any punctuation, but those
are "struct oidmap" and "struct oidset" in the code. We _could_ make
this "oidarray" to match, but somehow it looks uglier to me because of
the length of "array" (plus it would be a very invasive patch for little
gain).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 10:59:08 -07:00

507 lines
12 KiB
C

#include "cache.h"
#include "attr.h"
#include "object.h"
#include "blob.h"
#include "commit.h"
#include "tag.h"
#include "tree.h"
#include "delta.h"
#include "pack.h"
#include "tree-walk.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "progress.h"
#include "refs.h"
#include "khash.h"
#include "pack-bitmap.h"
#include "pack-objects.h"
#include "delta-islands.h"
#include "oid-array.h"
#include "config.h"
KHASH_INIT(str, const char *, void *, 1, kh_str_hash_func, kh_str_hash_equal)
static kh_oid_map_t *island_marks;
static unsigned island_counter;
static unsigned island_counter_core;
static kh_str_t *remote_islands;
struct remote_island {
uint64_t hash;
struct oid_array oids;
};
struct island_bitmap {
uint32_t refcount;
uint32_t bits[FLEX_ARRAY];
};
static uint32_t island_bitmap_size;
/*
* Allocate a new bitmap; if "old" is not NULL, the new bitmap will be a copy
* of "old". Otherwise, the new bitmap is empty.
*/
static struct island_bitmap *island_bitmap_new(const struct island_bitmap *old)
{
size_t size = sizeof(struct island_bitmap) + (island_bitmap_size * 4);
struct island_bitmap *b = xcalloc(1, size);
if (old)
memcpy(b, old, size);
b->refcount = 1;
return b;
}
static void island_bitmap_or(struct island_bitmap *a, const struct island_bitmap *b)
{
uint32_t i;
for (i = 0; i < island_bitmap_size; ++i)
a->bits[i] |= b->bits[i];
}
static int island_bitmap_is_subset(struct island_bitmap *self,
struct island_bitmap *super)
{
uint32_t i;
if (self == super)
return 1;
for (i = 0; i < island_bitmap_size; ++i) {
if ((self->bits[i] & super->bits[i]) != self->bits[i])
return 0;
}
return 1;
}
#define ISLAND_BITMAP_BLOCK(x) (x / 32)
#define ISLAND_BITMAP_MASK(x) (1 << (x % 32))
static void island_bitmap_set(struct island_bitmap *self, uint32_t i)
{
self->bits[ISLAND_BITMAP_BLOCK(i)] |= ISLAND_BITMAP_MASK(i);
}
static int island_bitmap_get(struct island_bitmap *self, uint32_t i)
{
return (self->bits[ISLAND_BITMAP_BLOCK(i)] & ISLAND_BITMAP_MASK(i)) != 0;
}
int in_same_island(const struct object_id *trg_oid, const struct object_id *src_oid)
{
khiter_t trg_pos, src_pos;
/* If we aren't using islands, assume everything goes together. */
if (!island_marks)
return 1;
/*
* If we don't have a bitmap for the target, we can delta it
* against anything -- it's not an important object
*/
trg_pos = kh_get_oid_map(island_marks, *trg_oid);
if (trg_pos >= kh_end(island_marks))
return 1;
/*
* if the source (our delta base) doesn't have a bitmap,
* we don't want to base any deltas on it!
*/
src_pos = kh_get_oid_map(island_marks, *src_oid);
if (src_pos >= kh_end(island_marks))
return 0;
return island_bitmap_is_subset(kh_value(island_marks, trg_pos),
kh_value(island_marks, src_pos));
}
int island_delta_cmp(const struct object_id *a, const struct object_id *b)
{
khiter_t a_pos, b_pos;
struct island_bitmap *a_bitmap = NULL, *b_bitmap = NULL;
if (!island_marks)
return 0;
a_pos = kh_get_oid_map(island_marks, *a);
if (a_pos < kh_end(island_marks))
a_bitmap = kh_value(island_marks, a_pos);
b_pos = kh_get_oid_map(island_marks, *b);
if (b_pos < kh_end(island_marks))
b_bitmap = kh_value(island_marks, b_pos);
if (a_bitmap) {
if (!b_bitmap || !island_bitmap_is_subset(a_bitmap, b_bitmap))
return -1;
}
if (b_bitmap) {
if (!a_bitmap || !island_bitmap_is_subset(b_bitmap, a_bitmap))
return 1;
}
return 0;
}
static struct island_bitmap *create_or_get_island_marks(struct object *obj)
{
khiter_t pos;
int hash_ret;
pos = kh_put_oid_map(island_marks, obj->oid, &hash_ret);
if (hash_ret)
kh_value(island_marks, pos) = island_bitmap_new(NULL);
return kh_value(island_marks, pos);
}
static void set_island_marks(struct object *obj, struct island_bitmap *marks)
{
struct island_bitmap *b;
khiter_t pos;
int hash_ret;
pos = kh_put_oid_map(island_marks, obj->oid, &hash_ret);
if (hash_ret) {
/*
* We don't have one yet; make a copy-on-write of the
* parent.
*/
marks->refcount++;
kh_value(island_marks, pos) = marks;
return;
}
/*
* We do have it. Make sure we split any copy-on-write before
* updating.
*/
b = kh_value(island_marks, pos);
if (b->refcount > 1) {
b->refcount--;
b = kh_value(island_marks, pos) = island_bitmap_new(b);
}
island_bitmap_or(b, marks);
}
static void mark_remote_island_1(struct repository *r,
struct remote_island *rl,
int is_core_island)
{
uint32_t i;
for (i = 0; i < rl->oids.nr; ++i) {
struct island_bitmap *marks;
struct object *obj = parse_object(r, &rl->oids.oid[i]);
if (!obj)
continue;
marks = create_or_get_island_marks(obj);
island_bitmap_set(marks, island_counter);
if (is_core_island && obj->type == OBJ_COMMIT)
obj->flags |= NEEDS_BITMAP;
/* If it was a tag, also make sure we hit the underlying object. */
while (obj && obj->type == OBJ_TAG) {
obj = ((struct tag *)obj)->tagged;
if (obj) {
parse_object(r, &obj->oid);
marks = create_or_get_island_marks(obj);
island_bitmap_set(marks, island_counter);
}
}
}
if (is_core_island)
island_counter_core = island_counter;
island_counter++;
}
struct tree_islands_todo {
struct object_entry *entry;
unsigned int depth;
};
static int tree_depth_compare(const void *a, const void *b)
{
const struct tree_islands_todo *todo_a = a;
const struct tree_islands_todo *todo_b = b;
return todo_a->depth - todo_b->depth;
}
void resolve_tree_islands(struct repository *r,
int progress,
struct packing_data *to_pack)
{
struct progress *progress_state = NULL;
struct tree_islands_todo *todo;
int nr = 0;
int i;
if (!island_marks)
return;
/*
* We process only trees, as commits and tags have already been handled
* (and passed their marks on to root trees, as well. We must make sure
* to process them in descending tree-depth order so that marks
* propagate down the tree properly, even if a sub-tree is found in
* multiple parent trees.
*/
ALLOC_ARRAY(todo, to_pack->nr_objects);
for (i = 0; i < to_pack->nr_objects; i++) {
if (oe_type(&to_pack->objects[i]) == OBJ_TREE) {
todo[nr].entry = &to_pack->objects[i];
todo[nr].depth = oe_tree_depth(to_pack, &to_pack->objects[i]);
nr++;
}
}
QSORT(todo, nr, tree_depth_compare);
if (progress)
progress_state = start_progress(_("Propagating island marks"), nr);
for (i = 0; i < nr; i++) {
struct object_entry *ent = todo[i].entry;
struct island_bitmap *root_marks;
struct tree *tree;
struct tree_desc desc;
struct name_entry entry;
khiter_t pos;
pos = kh_get_oid_map(island_marks, ent->idx.oid);
if (pos >= kh_end(island_marks))
continue;
root_marks = kh_value(island_marks, pos);
tree = lookup_tree(r, &ent->idx.oid);
if (!tree || parse_tree(tree) < 0)
die(_("bad tree object %s"), oid_to_hex(&ent->idx.oid));
init_tree_desc(&desc, tree->buffer, tree->size);
while (tree_entry(&desc, &entry)) {
struct object *obj;
if (S_ISGITLINK(entry.mode))
continue;
obj = lookup_object(r, &entry.oid);
if (!obj)
continue;
set_island_marks(obj, root_marks);
}
free_tree_buffer(tree);
display_progress(progress_state, i+1);
}
stop_progress(&progress_state);
free(todo);
}
static regex_t *island_regexes;
static unsigned int island_regexes_alloc, island_regexes_nr;
static const char *core_island_name;
static int island_config_callback(const char *k, const char *v, void *cb)
{
if (!strcmp(k, "pack.island")) {
struct strbuf re = STRBUF_INIT;
if (!v)
return config_error_nonbool(k);
ALLOC_GROW(island_regexes, island_regexes_nr + 1, island_regexes_alloc);
if (*v != '^')
strbuf_addch(&re, '^');
strbuf_addstr(&re, v);
if (regcomp(&island_regexes[island_regexes_nr], re.buf, REG_EXTENDED))
die(_("failed to load island regex for '%s': %s"), k, re.buf);
strbuf_release(&re);
island_regexes_nr++;
return 0;
}
if (!strcmp(k, "pack.islandcore"))
return git_config_string(&core_island_name, k, v);
return 0;
}
static void add_ref_to_island(const char *island_name, const struct object_id *oid)
{
uint64_t sha_core;
struct remote_island *rl = NULL;
int hash_ret;
khiter_t pos = kh_put_str(remote_islands, island_name, &hash_ret);
if (hash_ret) {
kh_key(remote_islands, pos) = xstrdup(island_name);
kh_value(remote_islands, pos) = xcalloc(1, sizeof(struct remote_island));
}
rl = kh_value(remote_islands, pos);
oid_array_append(&rl->oids, oid);
memcpy(&sha_core, oid->hash, sizeof(uint64_t));
rl->hash += sha_core;
}
static int find_island_for_ref(const char *refname, const struct object_id *oid,
int flags, void *data)
{
/*
* We should advertise 'ARRAY_SIZE(matches) - 2' as the max,
* so we can diagnose below a config with more capture groups
* than we support.
*/
regmatch_t matches[16];
int i, m;
struct strbuf island_name = STRBUF_INIT;
/* walk backwards to get last-one-wins ordering */
for (i = island_regexes_nr - 1; i >= 0; i--) {
if (!regexec(&island_regexes[i], refname,
ARRAY_SIZE(matches), matches, 0))
break;
}
if (i < 0)
return 0;
if (matches[ARRAY_SIZE(matches) - 1].rm_so != -1)
warning(_("island regex from config has "
"too many capture groups (max=%d)"),
(int)ARRAY_SIZE(matches) - 2);
for (m = 1; m < ARRAY_SIZE(matches); m++) {
regmatch_t *match = &matches[m];
if (match->rm_so == -1)
continue;
if (island_name.len)
strbuf_addch(&island_name, '-');
strbuf_add(&island_name, refname + match->rm_so, match->rm_eo - match->rm_so);
}
add_ref_to_island(island_name.buf, oid);
strbuf_release(&island_name);
return 0;
}
static struct remote_island *get_core_island(void)
{
if (core_island_name) {
khiter_t pos = kh_get_str(remote_islands, core_island_name);
if (pos < kh_end(remote_islands))
return kh_value(remote_islands, pos);
}
return NULL;
}
static void deduplicate_islands(struct repository *r)
{
struct remote_island *island, *core = NULL, **list;
unsigned int island_count, dst, src, ref, i = 0;
island_count = kh_size(remote_islands);
ALLOC_ARRAY(list, island_count);
kh_foreach_value(remote_islands, island, {
list[i++] = island;
});
for (ref = 0; ref + 1 < island_count; ref++) {
for (src = ref + 1, dst = src; src < island_count; src++) {
if (list[ref]->hash == list[src]->hash)
continue;
if (src != dst)
list[dst] = list[src];
dst++;
}
island_count = dst;
}
island_bitmap_size = (island_count / 32) + 1;
core = get_core_island();
for (i = 0; i < island_count; ++i) {
mark_remote_island_1(r, list[i], core && list[i]->hash == core->hash);
}
free(list);
}
void load_delta_islands(struct repository *r, int progress)
{
island_marks = kh_init_oid_map();
remote_islands = kh_init_str();
git_config(island_config_callback, NULL);
for_each_ref(find_island_for_ref, NULL);
deduplicate_islands(r);
if (progress)
fprintf(stderr, _("Marked %d islands, done.\n"), island_counter);
}
void propagate_island_marks(struct commit *commit)
{
khiter_t pos = kh_get_oid_map(island_marks, commit->object.oid);
if (pos < kh_end(island_marks)) {
struct commit_list *p;
struct island_bitmap *root_marks = kh_value(island_marks, pos);
parse_commit(commit);
set_island_marks(&get_commit_tree(commit)->object, root_marks);
for (p = commit->parents; p; p = p->next)
set_island_marks(&p->item->object, root_marks);
}
}
int compute_pack_layers(struct packing_data *to_pack)
{
uint32_t i;
if (!core_island_name || !island_marks)
return 1;
for (i = 0; i < to_pack->nr_objects; ++i) {
struct object_entry *entry = &to_pack->objects[i];
khiter_t pos = kh_get_oid_map(island_marks, entry->idx.oid);
oe_set_layer(to_pack, entry, 1);
if (pos < kh_end(island_marks)) {
struct island_bitmap *bitmap = kh_value(island_marks, pos);
if (island_bitmap_get(bitmap, island_counter_core))
oe_set_layer(to_pack, entry, 0);
}
}
return 2;
}