diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | khash.h | 338 | ||||
| -rw-r--r-- | pack-bitmap.c | 970 | ||||
| -rw-r--r-- | pack-bitmap.h | 43 |
4 files changed, 1353 insertions, 0 deletions
@@ -699,6 +699,7 @@ LIB_H += object.h LIB_H += pack-objects.h LIB_H += pack-revindex.h LIB_H += pack.h +LIB_H += pack-bitmap.h LIB_H += parse-options.h LIB_H += patch-ids.h LIB_H += pathspec.h @@ -837,6 +838,7 @@ LIB_OBJS += notes-cache.o LIB_OBJS += notes-merge.o LIB_OBJS += notes-utils.o LIB_OBJS += object.o +LIB_OBJS += pack-bitmap.o LIB_OBJS += pack-check.o LIB_OBJS += pack-objects.o LIB_OBJS += pack-revindex.o @@ -0,0 +1,338 @@ +/* The MIT License + + Copyright (c) 2008, 2009, 2011 by Attractive Chaos <attractor@live.co.uk> + + Permission is hereby granted, free of charge, to any person obtaining + a copy of this software and associated documentation files (the + "Software"), to deal in the Software without restriction, including + without limitation the rights to use, copy, modify, merge, publish, + distribute, sublicense, and/or sell copies of the Software, and to + permit persons to whom the Software is furnished to do so, subject to + the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +*/ + +#ifndef __AC_KHASH_H +#define __AC_KHASH_H + +#define AC_VERSION_KHASH_H "0.2.8" + +typedef uint32_t khint32_t; +typedef uint64_t khint64_t; + +typedef khint32_t khint_t; +typedef khint_t khiter_t; + +#define __ac_isempty(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&2) +#define __ac_isdel(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&1) +#define __ac_iseither(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&3) +#define __ac_set_isdel_false(flag, i) (flag[i>>4]&=~(1ul<<((i&0xfU)<<1))) +#define __ac_set_isempty_false(flag, i) (flag[i>>4]&=~(2ul<<((i&0xfU)<<1))) +#define __ac_set_isboth_false(flag, i) (flag[i>>4]&=~(3ul<<((i&0xfU)<<1))) +#define __ac_set_isdel_true(flag, i) (flag[i>>4]|=1ul<<((i&0xfU)<<1)) + +#define __ac_fsize(m) ((m) < 16? 1 : (m)>>4) + +#define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x)) + +static inline khint_t __ac_X31_hash_string(const char *s) +{ + khint_t h = (khint_t)*s; + if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s; + return h; +} + +#define kh_str_hash_func(key) __ac_X31_hash_string(key) +#define kh_str_hash_equal(a, b) (strcmp(a, b) == 0) + +static const double __ac_HASH_UPPER = 0.77; + +#define __KHASH_TYPE(name, khkey_t, khval_t) \ + typedef struct { \ + khint_t n_buckets, size, n_occupied, upper_bound; \ + khint32_t *flags; \ + khkey_t *keys; \ + khval_t *vals; \ + } kh_##name##_t; + +#define __KHASH_PROTOTYPES(name, khkey_t, khval_t) \ + extern kh_##name##_t *kh_init_##name(void); \ + extern void kh_destroy_##name(kh_##name##_t *h); \ + extern void kh_clear_##name(kh_##name##_t *h); \ + extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); \ + extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \ + extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \ + extern void kh_del_##name(kh_##name##_t *h, khint_t x); + +#define __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \ + SCOPE kh_##name##_t *kh_init_##name(void) { \ + return (kh_##name##_t*)xcalloc(1, sizeof(kh_##name##_t)); \ + } \ + SCOPE void kh_destroy_##name(kh_##name##_t *h) \ + { \ + if (h) { \ + free((void *)h->keys); free(h->flags); \ + free((void *)h->vals); \ + free(h); \ + } \ + } \ + SCOPE void kh_clear_##name(kh_##name##_t *h) \ + { \ + if (h && h->flags) { \ + memset(h->flags, 0xaa, __ac_fsize(h->n_buckets) * sizeof(khint32_t)); \ + h->size = h->n_occupied = 0; \ + } \ + } \ + SCOPE khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key) \ + { \ + if (h->n_buckets) { \ + khint_t k, i, last, mask, step = 0; \ + mask = h->n_buckets - 1; \ + k = __hash_func(key); i = k & mask; \ + last = i; \ + while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \ + i = (i + (++step)) & mask; \ + if (i == last) return h->n_buckets; \ + } \ + return __ac_iseither(h->flags, i)? h->n_buckets : i; \ + } else return 0; \ + } \ + SCOPE int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \ + { /* This function uses 0.25*n_buckets bytes of working space instead of [sizeof(key_t+val_t)+.25]*n_buckets. */ \ + khint32_t *new_flags = NULL; \ + khint_t j = 1; \ + { \ + kroundup32(new_n_buckets); \ + if (new_n_buckets < 4) new_n_buckets = 4; \ + if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0; /* requested size is too small */ \ + else { /* hash table size to be changed (shrink or expand); rehash */ \ + new_flags = (khint32_t*)xmalloc(__ac_fsize(new_n_buckets) * sizeof(khint32_t)); \ + if (!new_flags) return -1; \ + memset(new_flags, 0xaa, __ac_fsize(new_n_buckets) * sizeof(khint32_t)); \ + if (h->n_buckets < new_n_buckets) { /* expand */ \ + khkey_t *new_keys = (khkey_t*)xrealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \ + if (!new_keys) return -1; \ + h->keys = new_keys; \ + if (kh_is_map) { \ + khval_t *new_vals = (khval_t*)xrealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \ + if (!new_vals) return -1; \ + h->vals = new_vals; \ + } \ + } /* otherwise shrink */ \ + } \ + } \ + if (j) { /* rehashing is needed */ \ + for (j = 0; j != h->n_buckets; ++j) { \ + if (__ac_iseither(h->flags, j) == 0) { \ + khkey_t key = h->keys[j]; \ + khval_t val; \ + khint_t new_mask; \ + new_mask = new_n_buckets - 1; \ + if (kh_is_map) val = h->vals[j]; \ + __ac_set_isdel_true(h->flags, j); \ + while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \ + khint_t k, i, step = 0; \ + k = __hash_func(key); \ + i = k & new_mask; \ + while (!__ac_isempty(new_flags, i)) i = (i + (++step)) & new_mask; \ + __ac_set_isempty_false(new_flags, i); \ + if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { /* kick out the existing element */ \ + { khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \ + if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \ + __ac_set_isdel_true(h->flags, i); /* mark it as deleted in the old hash table */ \ + } else { /* write the element and jump out of the loop */ \ + h->keys[i] = key; \ + if (kh_is_map) h->vals[i] = val; \ + break; \ + } \ + } \ + } \ + } \ + if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \ + h->keys = (khkey_t*)xrealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \ + if (kh_is_map) h->vals = (khval_t*)xrealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \ + } \ + free(h->flags); /* free the working space */ \ + h->flags = new_flags; \ + h->n_buckets = new_n_buckets; \ + h->n_occupied = h->size; \ + h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \ + } \ + return 0; \ + } \ + SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \ + { \ + khint_t x; \ + if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \ + if (h->n_buckets > (h->size<<1)) { \ + if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \ + *ret = -1; return h->n_buckets; \ + } \ + } else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \ + *ret = -1; return h->n_buckets; \ + } \ + } /* TODO: to implement automatically shrinking; resize() already support shrinking */ \ + { \ + khint_t k, i, site, last, mask = h->n_buckets - 1, step = 0; \ + x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \ + if (__ac_isempty(h->flags, i)) x = i; /* for speed up */ \ + else { \ + last = i; \ + while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \ + if (__ac_isdel(h->flags, i)) site = i; \ + i = (i + (++step)) & mask; \ + if (i == last) { x = site; break; } \ + } \ + if (x == h->n_buckets) { \ + if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \ + else x = i; \ + } \ + } \ + } \ + if (__ac_isempty(h->flags, x)) { /* not present at all */ \ + h->keys[x] = key; \ + __ac_set_isboth_false(h->flags, x); \ + ++h->size; ++h->n_occupied; \ + *ret = 1; \ + } else if (__ac_isdel(h->flags, x)) { /* deleted */ \ + h->keys[x] = key; \ + __ac_set_isboth_false(h->flags, x); \ + ++h->size; \ + *ret = 2; \ + } else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \ + return x; \ + } \ + SCOPE void kh_del_##name(kh_##name##_t *h, khint_t x) \ + { \ + if (x != h->n_buckets && !__ac_iseither(h->flags, x)) { \ + __ac_set_isdel_true(h->flags, x); \ + --h->size; \ + } \ + } + +#define KHASH_DECLARE(name, khkey_t, khval_t) \ + __KHASH_TYPE(name, khkey_t, khval_t) \ + __KHASH_PROTOTYPES(name, khkey_t, khval_t) + +#define KHASH_INIT2(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \ + __KHASH_TYPE(name, khkey_t, khval_t) \ + __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) + +#define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \ + KHASH_INIT2(name, static inline, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) + +/* Other convenient macros... */ + +/*! @function + @abstract Test whether a bucket contains data. + @param h Pointer to the hash table [khash_t(name)*] + @param x Iterator to the bucket [khint_t] + @return 1 if containing data; 0 otherwise [int] + */ +#define kh_exist(h, x) (!__ac_iseither((h)->flags, (x))) + +/*! @function + @abstract Get key given an iterator + @param h Pointer to the hash table [khash_t(name)*] + @param x Iterator to the bucket [khint_t] + @return Key [type of keys] + */ +#define kh_key(h, x) ((h)->keys[x]) + +/*! @function + @abstract Get value given an iterator + @param h Pointer to the hash table [khash_t(name)*] + @param x Iterator to the bucket [khint_t] + @return Value [type of values] + @discussion For hash sets, calling this results in segfault. + */ +#define kh_val(h, x) ((h)->vals[x]) + +/*! @function + @abstract Alias of kh_val() + */ +#define kh_value(h, x) ((h)->vals[x]) + +/*! @function + @abstract Get the start iterator + @param h Pointer to the hash table [khash_t(name)*] + @return The start iterator [khint_t] + */ +#define kh_begin(h) (khint_t)(0) + +/*! @function + @abstract Get the end iterator + @param h Pointer to the hash table [khash_t(name)*] + @return The end iterator [khint_t] + */ +#define kh_end(h) ((h)->n_buckets) + +/*! @function + @abstract Get the number of elements in the hash table + @param h Pointer to the hash table [khash_t(name)*] + @return Number of elements in the hash table [khint_t] + */ +#define kh_size(h) ((h)->size) + +/*! @function + @abstract Get the number of buckets in the hash table + @param h Pointer to the hash table [khash_t(name)*] + @return Number of buckets in the hash table [khint_t] + */ +#define kh_n_buckets(h) ((h)->n_buckets) + +/*! @function + @abstract Iterate over the entries in the hash table + @param h Pointer to the hash table [khash_t(name)*] + @param kvar Variable to which key will be assigned + @param vvar Variable to which value will be assigned + @param code Block of code to execute + */ +#define kh_foreach(h, kvar, vvar, code) { khint_t __i; \ + for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \ + if (!kh_exist(h,__i)) continue; \ + (kvar) = kh_key(h,__i); \ + (vvar) = kh_val(h,__i); \ + code; \ + } } + +/*! @function + @abstract Iterate over the values in the hash table + @param h Pointer to the hash table [khash_t(name)*] + @param vvar Variable to which value will be assigned + @param code Block of code to execute + */ +#define kh_foreach_value(h, vvar, code) { khint_t __i; \ + for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \ + if (!kh_exist(h,__i)) continue; \ + (vvar) = kh_val(h,__i); \ + code; \ + } } + +static inline khint_t __kh_oid_hash(const unsigned char *oid) +{ + khint_t hash; + memcpy(&hash, oid, sizeof(hash)); + return hash; +} + +#define __kh_oid_cmp(a, b) (hashcmp(a, b) == 0) + +KHASH_INIT(sha1, const unsigned char *, void *, 1, __kh_oid_hash, __kh_oid_cmp) +typedef kh_sha1_t khash_sha1; + +KHASH_INIT(sha1_pos, const unsigned char *, int, 1, __kh_oid_hash, __kh_oid_cmp) +typedef kh_sha1_pos_t khash_sha1_pos; + +#endif /* __AC_KHASH_H */ diff --git a/pack-bitmap.c b/pack-bitmap.c new file mode 100644 index 0000000..33e7482 --- /dev/null +++ b/pack-bitmap.c @@ -0,0 +1,970 @@ +#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" + +/* + * An entry on the bitmap index, representing the bitmap for a given + * commit. + */ +struct stored_bitmap { + unsigned char sha1[20]; + struct ewah_bitmap *root; + struct stored_bitmap *xor; + int flags; +}; + +/* + * The currently active bitmap index. 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. + */ +static struct bitmap_index { + /* Packfile to which this bitmap index belongs to */ + struct packed_git *pack; + + /* reverse index for the packfile */ + struct pack_revindex *reverse_index; + + /* + * 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 SHA1 -> `stored_bitmap` for all the bitmapped comits */ + khash_sha1 *bitmaps; + + /* Number of bitmapped commits */ + uint32_t entry_count; + + /* + * 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; + khash_sha1_pos *positions; + } ext_index; + + /* Bitmap result of the last performed walk */ + struct bitmap *result; + + /* Version of the bitmap index */ + unsigned int version; + + unsigned loaded : 1; + +} bitmap_git; + +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(); + + int 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) + 20) + 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)"); + } + + index->entry_count = ntohl(header->entry_count); + index->map_pos += sizeof(*header); + return 0; +} + +static struct stored_bitmap *store_bitmap(struct bitmap_index *index, + struct ewah_bitmap *root, + const unsigned char *sha1, + 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; + hashcpy(stored->sha1, sha1); + + hash_pos = kh_put_sha1(index->bitmaps, stored->sha1, &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", sha1_to_hex(sha1)); + return NULL; + } + + kh_value(index->bitmaps, hash_pos) = stored; + return stored; +} + +static int load_bitmap_entries_v1(struct bitmap_index *index) +{ + static const size_t MAX_XOR_OFFSET = 160; + + uint32_t i; + struct stored_bitmap **recent_bitmaps; + struct bitmap_disk_entry *entry; + + recent_bitmaps = xcalloc(MAX_XOR_OFFSET, sizeof(struct stored_bitmap)); + + 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; + const unsigned char *sha1; + + entry = (struct bitmap_disk_entry *)(index->map + index->map_pos); + index->map_pos += sizeof(struct bitmap_disk_entry); + + commit_idx_pos = ntohl(entry->object_pos); + sha1 = nth_packed_object_sha1(index->pack, commit_idx_pos); + + xor_offset = (int)entry->xor_offset; + flags = (int)entry->flags; + + 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, sha1, xor_bitmap, flags); + } + + return 0; +} + +static int open_pack_bitmap_1(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_noatime(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(void) +{ + assert(bitmap_git.map && !bitmap_git.loaded); + + bitmap_git.bitmaps = kh_init_sha1(); + bitmap_git.ext_index.positions = kh_init_sha1_pos(); + bitmap_git.reverse_index = revindex_for_pack(bitmap_git.pack); + + 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; + + bitmap_git.loaded = 1; + return 0; + +failed: + munmap(bitmap_git.map, bitmap_git.map_size); + bitmap_git.map = NULL; + bitmap_git.map_size = 0; + return -1; +} + +char *pack_bitmap_filename(struct packed_git *p) +{ + char *idx_name; + int len; + + len = strlen(p->pack_name) - strlen(".pack"); + idx_name = xmalloc(len + strlen(".bitmap") + 1); + + memcpy(idx_name, p->pack_name, len); + memcpy(idx_name + len, ".bitmap", strlen(".bitmap") + 1); + + return idx_name; +} + +static int open_pack_bitmap(void) +{ + struct packed_git *p; + int ret = -1; + + assert(!bitmap_git.map && !bitmap_git.loaded); + + prepare_packed_git(); + for (p = packed_git; p; p = p->next) { + if (open_pack_bitmap_1(p) == 0) + ret = 0; + } + + return ret; +} + +int prepare_bitmap_git(void) +{ + if (bitmap_git.loaded) + return 0; + + if (!open_pack_bitmap()) + return load_pack_bitmap(); + + return -1; +} + +struct include_data { + struct bitmap *base; + struct bitmap *seen; +}; + +static inline int bitmap_position_extended(const unsigned char *sha1) +{ + khash_sha1_pos *positions = bitmap_git.ext_index.positions; + khiter_t pos = kh_get_sha1_pos(positions, sha1); + + 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(const unsigned char *sha1) +{ + off_t offset = find_pack_entry_one(sha1, bitmap_git.pack); + if (!offset) + return -1; + + return find_revindex_position(bitmap_git.reverse_index, offset); +} + +static int bitmap_position(const unsigned char *sha1) +{ + int pos = bitmap_position_packfile(sha1); + return (pos >= 0) ? pos : bitmap_position_extended(sha1); +} + +static int ext_index_add_object(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_sha1_pos(eindex->positions, object->sha1, &hash_ret); + if (hash_ret > 0) { + if (eindex->count >= eindex->alloc) { + eindex->alloc = (eindex->alloc + 16) * 3 / 2; + eindex->objects = xrealloc(eindex->objects, + eindex->alloc * sizeof(struct object *)); + eindex->hashes = xrealloc(eindex->hashes, + eindex->alloc * sizeof(uint32_t)); + } + + 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; +} + +static void show_object(struct object *object, const struct name_path *path, + const char *last, void *data) +{ + struct bitmap *base = data; + int bitmap_pos; + + bitmap_pos = bitmap_position(object->sha1); + + if (bitmap_pos < 0) { + char *name = path_name(path, last); + bitmap_pos = ext_index_add_object(object, name); + free(name); + } + + bitmap_set(base, bitmap_pos); +} + +static void show_commit(struct commit *commit, void *data) +{ +} + +static int add_to_include_set(struct include_data *data, + const unsigned char *sha1, + 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_sha1(bitmap_git.bitmaps, sha1); + 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(commit->object.sha1); + if (bitmap_pos < 0) + bitmap_pos = ext_index_add_object((struct object *)commit, NULL); + + if (!add_to_include_set(data, commit->object.sha1, 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 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_sha1(bitmap_git.bitmaps, object->sha1); + + 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, ¬_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(object->sha1); + + 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; + + if (base == NULL) + base = bitmap_new(); + + 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"); + + traverse_commit_list(revs, show_commit, show_object, base); + } + + return base; +} + +static void show_extended_objects(struct bitmap *objects, + show_reachable_fn show_reach) +{ + 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]; + show_reach(obj->sha1, obj->type, 0, eindex->hashes[i], NULL, 0); + } +} + +static void show_objects_for_type( + struct bitmap *objects, + struct ewah_bitmap *type_filter, + enum object_type object_type, + show_reachable_fn show_reach) +{ + size_t pos = 0, i = 0; + uint32_t offset; + + struct ewah_iterator it; + eword_t filter; + + if (bitmap_git.reuse_objects == bitmap_git.pack->num_objects) + return; + + ewah_iterator_init(&it, type_filter); + + while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) { + eword_t word = objects->words[i] & filter; + + for (offset = 0; offset < BITS_IN_WORD; ++offset) { + const unsigned char *sha1; + struct revindex_entry *entry; + uint32_t hash = 0; + + if ((word >> offset) == 0) + break; + + offset += ewah_bit_ctz64(word >> offset); + + if (pos + offset < bitmap_git.reuse_objects) + continue; + + entry = &bitmap_git.reverse_index->revindex[pos + offset]; + sha1 = nth_packed_object_sha1(bitmap_git.pack, entry->nr); + + show_reach(sha1, object_type, 0, hash, bitmap_git.pack, entry->offset); + } + + pos += BITS_IN_WORD; + i++; + } +} + +static int in_bitmapped_pack(struct object_list *roots) +{ + while (roots) { + struct object *object = roots->item; + roots = roots->next; + + if (find_pack_entry_one(object->sha1, bitmap_git.pack) > 0) + return 1; + } + + return 0; +} + +int prepare_bitmap_walk(struct rev_info *revs) +{ + unsigned int i; + unsigned int pending_nr = revs->pending.nr; + struct object_array_entry *pending_e = revs->pending.objects; + + struct object_list *wants = NULL; + struct object_list *haves = NULL; + + struct bitmap *wants_bitmap = NULL; + struct bitmap *haves_bitmap = NULL; + + if (!bitmap_git.loaded) { + /* try to open a bitmapped pack, but don't parse it yet + * because we may not need to use it */ + if (open_pack_bitmap() < 0) + return -1; + } + + for (i = 0; i < pending_nr; ++i) { + struct object *object = pending_e[i].item; + + if (object->type == OBJ_NONE) + parse_object_or_die(object->sha1, 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); + + if (!tag->tagged) + die("bad tag"); + object = parse_object_or_die(tag->tagged->sha1, 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(haves)) + return -1; + + /* if we don't want anything, we're done here */ + if (!wants) + return -1; + + /* + * 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 (!bitmap_git.loaded && load_pack_bitmap() < 0) + return -1; + + revs->pending.nr = 0; + revs->pending.alloc = 0; + revs->pending.objects = NULL; + + if (haves) { + haves_bitmap = find_objects(revs, haves, NULL); + reset_revision_walk(); + + if (haves_bitmap == NULL) + die("BUG: failed to perform bitmap walk"); + } + + wants_bitmap = find_objects(revs, wants, haves_bitmap); + + if (!wants_bitmap) + die("BUG: failed to perform bitmap walk"); + + if (haves_bitmap) + bitmap_and_not(wants_bitmap, haves_bitmap); + + bitmap_git.result = wants_bitmap; + + bitmap_free(haves_bitmap); + return 0; +} + +int reuse_partial_packfile_from_bitmap(struct packed_git **packfile, + uint32_t *entries, + off_t *up_to) +{ + /* + * Reuse the packfile content if we need more than + * 90% of its objects + */ + static const double REUSE_PERCENT = 0.9; + + struct bitmap *result = bitmap_git.result; + uint32_t reuse_threshold; + uint32_t i, reuse_objects = 0; + + assert(result); + + for (i = 0; i < result->word_alloc; ++i) { + if (result->words[i] != (eword_t)~0) { + reuse_objects += ewah_bit_ctz64(~result->words[i]); + break; + } + + reuse_objects += BITS_IN_WORD; + } + +#ifdef GIT_BITMAP_DEBUG + { + const unsigned char *sha1; + struct revindex_entry *entry; + + entry = &bitmap_git.reverse_index->revindex[reuse_objects]; + sha1 = nth_packed_object_sha1(bitmap_git.pack, entry->nr); + + fprintf(stderr, "Failed to reuse at %d (%016llx)\n", + reuse_objects, result->words[i]); + fprintf(stderr, " %s\n", sha1_to_hex(sha1)); + } +#endif + + if (!reuse_objects) + return -1; + + if (reuse_objects >= bitmap_git.pack->num_objects) { + bitmap_git.reuse_objects = *entries = bitmap_git.pack->num_objects; + *up_to = -1; /* reuse the full pack */ + *packfile = bitmap_git.pack; + return 0; + } + + reuse_threshold = bitmap_popcount(bitmap_git.result) * REUSE_PERCENT; + + if (reuse_objects < reuse_threshold) + return -1; + + bitmap_git.reuse_objects = *entries = reuse_objects; + *up_to = bitmap_git.reverse_index->revindex[reuse_objects].offset; + *packfile = bitmap_git.pack; + + return 0; +} + +void traverse_bitmap_commit_list(show_reachable_fn show_reachable) +{ + assert(bitmap_git.result); + + show_objects_for_type(bitmap_git.result, bitmap_git.commits, + OBJ_COMMIT, show_reachable); + show_objects_for_type(bitmap_git.result, bitmap_git.trees, + OBJ_TREE, show_reachable); + show_objects_for_type(bitmap_git.result, bitmap_git.blobs, + OBJ_BLOB, show_reachable); + show_objects_for_type(bitmap_git.result, bitmap_git.tags, + OBJ_TAG, show_reachable); + + show_extended_objects(bitmap_git.result, show_reachable); + + bitmap_free(bitmap_git.result); + bitmap_git.result = NULL; +} + +static uint32_t count_object_type(struct bitmap *objects, + enum object_type type) +{ + struct eindex *eindex = &bitmap_git.ext_index; + + uint32_t i = 0, count = 0; + struct ewah_iterator it; + eword_t filter; + + 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: + return 0; + } + + 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(uint32_t *commits, uint32_t *trees, + uint32_t *blobs, uint32_t *tags) +{ + assert(bitmap_git.result); + + if (commits) + *commits = count_object_type(bitmap_git.result, OBJ_COMMIT); + + if (trees) + *trees = count_object_type(bitmap_git.result, OBJ_TREE); + + if (blobs) + *blobs = count_object_type(bitmap_git.result, OBJ_BLOB); + + if (tags) + *tags = count_object_type(bitmap_git.result, OBJ_TAG); +} + +struct bitmap_test_data { + struct bitmap *base; + struct progress *prg; + size_t seen; +}; + +static void test_show_object(struct object *object, + const struct name_path *path, + const char *last, void *data) +{ + struct bitmap_test_data *tdata = data; + int bitmap_pos; + + bitmap_pos = bitmap_position(object->sha1); + if (bitmap_pos < 0) + die("Object not in bitmap: %s\n", sha1_to_hex(object->sha1)); + + 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(commit->object.sha1); + if (bitmap_pos < 0) + die("Object not in bitmap: %s\n", sha1_to_hex(commit->object.sha1)); + + 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; + + if (prepare_bitmap_git()) + 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_sha1(bitmap_git.bitmaps, root->sha1); + + 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", + sha1_to_hex(root->sha1), (int)bm->bit_size, ewah_checksum(bm)); + + result = ewah_to_bitmap(bm); + } + + if (result == NULL) + die("Commit %s doesn't have an indexed bitmap", sha1_to_hex(root->sha1)); + + 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.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"); +} diff --git a/pack-bitmap.h b/pack-bitmap.h new file mode 100644 index 0000000..b4510d5 --- /dev/null +++ b/pack-bitmap.h @@ -0,0 +1,43 @@ +#ifndef PACK_BITMAP_H +#define PACK_BITMAP_H + +#include "ewah/ewok.h" +#include "khash.h" + +struct bitmap_disk_entry { + uint32_t object_pos; + uint8_t xor_offset; + uint8_t flags; +} __attribute__((packed)); + +struct bitmap_disk_header { + char magic[4]; + uint16_t version; + uint16_t options; + uint32_t entry_count; + unsigned char checksum[20]; +}; + +static const char BITMAP_IDX_SIGNATURE[] = {'B', 'I', 'T', 'M'}; + +enum pack_bitmap_opts { + BITMAP_OPT_FULL_DAG = 1 +}; + +typedef int (*show_reachable_fn)( + const unsigned char *sha1, + enum object_type type, + int flags, + uint32_t hash, + struct packed_git *found_pack, + off_t found_offset); + +int prepare_bitmap_git(void); +void count_bitmap_commit_list(uint32_t *commits, uint32_t *trees, uint32_t *blobs, uint32_t *tags); +void traverse_bitmap_commit_list(show_reachable_fn show_reachable); +void test_bitmap_walk(struct rev_info *revs); +char *pack_bitmap_filename(struct packed_git *p); +int prepare_bitmap_walk(struct rev_info *revs); +int reuse_partial_packfile_from_bitmap(struct packed_git **packfile, uint32_t *entries, off_t *up_to); + +#endif |