diff options
Diffstat (limited to 'delta-islands.c')
| -rw-r--r-- | delta-islands.c | 502 |
1 files changed, 502 insertions, 0 deletions
diff --git a/delta-islands.c b/delta-islands.c new file mode 100644 index 0000000..8e5018e --- /dev/null +++ b/delta-islands.c @@ -0,0 +1,502 @@ +#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 "sha1-array.h" +#include "config.h" + +KHASH_INIT(str, const char *, void *, 1, kh_str_hash_func, kh_str_hash_equal) + +static khash_sha1 *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_sha1(island_marks, trg_oid->hash); + 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_sha1(island_marks, src_oid->hash); + 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_sha1(island_marks, a->hash); + if (a_pos < kh_end(island_marks)) + a_bitmap = kh_value(island_marks, a_pos); + + b_pos = kh_get_sha1(island_marks, b->hash); + 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_sha1(island_marks, obj->oid.hash, &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_sha1(island_marks, obj->oid.hash, &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 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(the_repository, &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(the_repository, &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(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_sha1(island_marks, ent->idx.oid.hash); + if (pos >= kh_end(island_marks)) + continue; + + root_marks = kh_value(island_marks, pos); + + tree = lookup_tree(the_repository, &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(the_repository, entry.oid->hash); + 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(void) +{ + 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(list[i], core && list[i]->hash == core->hash); + } + + free(list); +} + +void load_delta_islands(void) +{ + island_marks = kh_init_sha1(); + remote_islands = kh_init_str(); + + git_config(island_config_callback, NULL); + for_each_ref(find_island_for_ref, NULL); + deduplicate_islands(); + + fprintf(stderr, _("Marked %d islands, done.\n"), island_counter); +} + +void propagate_island_marks(struct commit *commit) +{ + khiter_t pos = kh_get_sha1(island_marks, commit->object.oid.hash); + + 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_sha1(island_marks, entry->idx.oid.hash); + + 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; +} |