#include "cache.h"
#include "object.h"
-#include "delta.h"
#include "pack.h"
-#include "csum-file.h"
-#include <sys/time.h>
+#include "pack-objects.h"
-static const char pack_usage[] = "git-pack-objects [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
-
-struct object_entry {
- unsigned char sha1[20];
- unsigned long size;
- unsigned long offset;
- unsigned int depth;
- unsigned int hash;
- enum object_type type;
- unsigned long delta_size;
- struct object_entry *delta;
-};
-
-static unsigned char object_list_sha1[20];
-static int non_empty = 0;
-static int local = 0;
-static int incremental = 0;
-static struct object_entry **sorted_by_sha, **sorted_by_type;
-static struct object_entry *objects = NULL;
-static int nr_objects = 0, nr_alloc = 0;
-static const char *base_name;
-static unsigned char pack_file_sha1[20];
-static int progress = 0;
-
-static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
-{
- unsigned long othersize, delta_size;
- char type[10];
- void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
- void *delta_buf;
-
- if (!otherbuf)
- die("unable to read %s", sha1_to_hex(entry->delta->sha1));
- delta_buf = diff_delta(otherbuf, othersize,
- buf, size, &delta_size, 0);
- if (!delta_buf || delta_size != entry->delta_size)
- die("delta size changed");
- free(buf);
- free(otherbuf);
- return delta_buf;
-}
-
-/*
- * The per-object header is a pretty dense thing, which is
- * - first byte: low four bits are "size", then three bits of "type",
- * and the high bit is "size continues".
- * - each byte afterwards: low seven bits are size continuation,
- * with the high bit being "size continues"
- */
-static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
+static uint32_t locate_object_entry_hash(struct packing_data *pdata,
+ const unsigned char *sha1,
+ int *found)
{
- int n = 1;
- unsigned char c;
-
- if (type < OBJ_COMMIT || type > OBJ_DELTA)
- die("bad type %d", type);
-
- c = (type << 4) | (size & 15);
- size >>= 4;
- while (size) {
- *hdr++ = c | 0x80;
- c = size & 0x7f;
- size >>= 7;
- n++;
- }
- *hdr = c;
- return n;
-}
+ uint32_t i, mask = (pdata->index_size - 1);
-static unsigned long write_object(struct sha1file *f, struct object_entry *entry)
-{
- unsigned long size;
- char type[10];
- void *buf = read_sha1_file(entry->sha1, type, &size);
- unsigned char header[10];
- unsigned hdrlen, datalen;
- enum object_type obj_type;
+ i = sha1hash(sha1) & mask;
- if (!buf)
- die("unable to read %s", sha1_to_hex(entry->sha1));
- if (size != entry->size)
- die("object %s size inconsistency (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
-
- /*
- * The object header is a byte of 'type' followed by zero or
- * more bytes of length. For deltas, the 20 bytes of delta sha1
- * follows that.
- */
- obj_type = entry->type;
- if (entry->delta) {
- buf = delta_against(buf, size, entry);
- size = entry->delta_size;
- obj_type = OBJ_DELTA;
- }
- hdrlen = encode_header(obj_type, size, header);
- sha1write(f, header, hdrlen);
- if (entry->delta) {
- sha1write(f, entry->delta, 20);
- hdrlen += 20;
- }
- datalen = sha1write_compressed(f, buf, size);
- free(buf);
- return hdrlen + datalen;
-}
-
-static unsigned long write_one(struct sha1file *f,
- struct object_entry *e,
- unsigned long offset)
-{
- if (e->offset)
- /* offset starts from header size and cannot be zero
- * if it is written already.
- */
- return offset;
- e->offset = offset;
- offset += write_object(f, e);
- /* if we are deltified, write out its base object. */
- if (e->delta)
- offset = write_one(f, e->delta, offset);
- return offset;
-}
-
-static void write_pack_file(void)
-{
- int i;
- struct sha1file *f;
- unsigned long offset;
- unsigned long mb;
- struct pack_header hdr;
-
- if (!base_name)
- f = sha1fd(1, "<stdout>");
- else
- f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "pack");
- hdr.hdr_signature = htonl(PACK_SIGNATURE);
- hdr.hdr_version = htonl(PACK_VERSION);
- hdr.hdr_entries = htonl(nr_objects);
- sha1write(f, &hdr, sizeof(hdr));
- offset = sizeof(hdr);
- for (i = 0; i < nr_objects; i++)
- offset = write_one(f, objects + i, offset);
+ while (pdata->index[i] > 0) {
+ uint32_t pos = pdata->index[i] - 1;
- sha1close(f, pack_file_sha1, 1);
- mb = offset >> 20;
- offset &= 0xfffff;
-}
-
-static void write_index_file(void)
-{
- int i;
- struct sha1file *f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "idx");
- struct object_entry **list = sorted_by_sha;
- struct object_entry **last = list + nr_objects;
- unsigned int array[256];
-
- /*
- * Write the first-level table (the list is sorted,
- * but we use a 256-entry lookup to be able to avoid
- * having to do eight extra binary search iterations).
- */
- for (i = 0; i < 256; i++) {
- struct object_entry **next = list;
- while (next < last) {
- struct object_entry *entry = *next;
- if (entry->sha1[0] != i)
- break;
- next++;
- }
- array[i] = htonl(next - sorted_by_sha);
- list = next;
- }
- sha1write(f, array, 256 * sizeof(int));
-
- /*
- * Write the actual SHA1 entries..
- */
- list = sorted_by_sha;
- for (i = 0; i < nr_objects; i++) {
- struct object_entry *entry = *list++;
- unsigned int offset = htonl(entry->offset);
- sha1write(f, &offset, 4);
- sha1write(f, entry->sha1, 20);
- }
- sha1write(f, pack_file_sha1, 20);
- sha1close(f, NULL, 1);
-}
-
-static int add_object_entry(unsigned char *sha1, unsigned int hash)
-{
- unsigned int idx = nr_objects;
- struct object_entry *entry;
-
- if (incremental || local) {
- struct packed_git *p;
-
- for (p = packed_git; p; p = p->next) {
- struct pack_entry e;
-
- if (find_pack_entry_one(sha1, &e, p)) {
- if (incremental)
- return 0;
- if (local && !p->pack_local)
- return 0;
- }
+ if (!hashcmp(sha1, pdata->objects[pos].idx.sha1)) {
+ *found = 1;
+ return i;
}
- }
- if (idx >= nr_alloc) {
- unsigned int needed = (idx + 1024) * 3 / 2;
- objects = xrealloc(objects, needed * sizeof(*entry));
- nr_alloc = needed;
+ i = (i + 1) & mask;
}
- entry = objects + idx;
- memset(entry, 0, sizeof(*entry));
- memcpy(entry->sha1, sha1, 20);
- entry->hash = hash;
- nr_objects = idx+1;
- return 1;
-}
-
-static void check_object(struct object_entry *entry)
-{
- char type[20];
-
- if (!sha1_object_info(entry->sha1, type, &entry->size)) {
- if (!strcmp(type, "commit")) {
- entry->type = OBJ_COMMIT;
- } else if (!strcmp(type, "tree")) {
- entry->type = OBJ_TREE;
- } else if (!strcmp(type, "blob")) {
- entry->type = OBJ_BLOB;
- } else if (!strcmp(type, "tag")) {
- entry->type = OBJ_TAG;
- } else
- die("unable to pack object %s of type %s",
- sha1_to_hex(entry->sha1), type);
- }
- else
- die("unable to get type of object %s",
- sha1_to_hex(entry->sha1));
-}
-
-static void get_object_details(void)
-{
- int i;
- struct object_entry *entry = objects;
-
- for (i = 0; i < nr_objects; i++)
- check_object(entry++);
-}
-
-typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
-
-static entry_sort_t current_sort;
-
-static int sort_comparator(const void *_a, const void *_b)
-{
- struct object_entry *a = *(struct object_entry **)_a;
- struct object_entry *b = *(struct object_entry **)_b;
- return current_sort(a,b);
-}
-
-static struct object_entry **create_sorted_list(entry_sort_t sort)
-{
- struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
- int i;
- for (i = 0; i < nr_objects; i++)
- list[i] = objects + i;
- current_sort = sort;
- qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
- return list;
+ *found = 0;
+ return i;
}
-static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
+static inline uint32_t closest_pow2(uint32_t v)
{
- return memcmp(a->sha1, b->sha1, 20);
+ v = v - 1;
+ v |= v >> 1;
+ v |= v >> 2;
+ v |= v >> 4;
+ v |= v >> 8;
+ v |= v >> 16;
+ return v + 1;
}
-static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
+static void rehash_objects(struct packing_data *pdata)
{
- if (a->type < b->type)
- return -1;
- if (a->type > b->type)
- return 1;
- if (a->hash < b->hash)
- return -1;
- if (a->hash > b->hash)
- return 1;
- if (a->size < b->size)
- return -1;
- if (a->size > b->size)
- return 1;
- return a < b ? -1 : (a > b);
-}
-
-struct unpacked {
+ uint32_t i;
struct object_entry *entry;
- void *data;
-};
-
-/*
- * We search for deltas _backwards_ in a list sorted by type and
- * by size, so that we see progressively smaller and smaller files.
- * That's because we prefer deltas to be from the bigger file
- * to the smaller - deletes are potentially cheaper, but perhaps
- * more importantly, the bigger file is likely the more recent
- * one.
- */
-static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_depth)
-{
- struct object_entry *cur_entry = cur->entry;
- struct object_entry *old_entry = old->entry;
- unsigned long size, oldsize, delta_size, sizediff;
- long max_size;
- void *delta_buf;
- /* Don't bother doing diffs between different types */
- if (cur_entry->type != old_entry->type)
- return -1;
+ pdata->index_size = closest_pow2(pdata->nr_objects * 3);
+ if (pdata->index_size < 1024)
+ pdata->index_size = 1024;
- size = cur_entry->size;
- if (size < 50)
- return -1;
- oldsize = old_entry->size;
- sizediff = oldsize > size ? oldsize - size : size - oldsize;
- if (sizediff > size / 8)
- return -1;
- if (old_entry->depth >= max_depth)
- return 0;
+ free(pdata->index);
+ pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index));
- /*
- * NOTE!
- *
- * We always delta from the bigger to the smaller, since that's
- * more space-efficient (deletes don't have to say _what_ they
- * delete).
- */
- max_size = size / 2 - 20;
- if (cur_entry->delta)
- max_size = cur_entry->delta_size-1;
- if (sizediff >= max_size)
- return -1;
- delta_buf = diff_delta(old->data, oldsize,
- cur->data, size, &delta_size, max_size);
- if (!delta_buf)
- return 0;
- cur_entry->delta = old_entry;
- cur_entry->delta_size = delta_size;
- cur_entry->depth = old_entry->depth + 1;
- free(delta_buf);
- return 0;
-}
+ entry = pdata->objects;
-static void find_deltas(struct object_entry **list, int window, int depth)
-{
- int i, idx;
- unsigned int array_size = window * sizeof(struct unpacked);
- struct unpacked *array = xmalloc(array_size);
- int eye_candy;
+ for (i = 0; i < pdata->nr_objects; i++) {
+ int found;
+ uint32_t ix = locate_object_entry_hash(pdata, entry->idx.sha1, &found);
- memset(array, 0, array_size);
- i = nr_objects;
- idx = 0;
- eye_candy = i - (nr_objects / 20);
+ if (found)
+ die("BUG: Duplicate object in hash");
- while (--i >= 0) {
- struct object_entry *entry = list[i];
- struct unpacked *n = array + idx;
- unsigned long size;
- char type[10];
- int j;
-
- if (progress && i <= eye_candy) {
- eye_candy -= nr_objects / 20;
- fputc('.', stderr);
- }
- free(n->data);
- n->entry = entry;
- n->data = read_sha1_file(entry->sha1, type, &size);
- if (size != entry->size)
- die("object %s inconsistent object length (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
- j = window;
- while (--j > 0) {
- unsigned int other_idx = idx + j;
- struct unpacked *m;
- if (other_idx >= window)
- other_idx -= window;
- m = array + other_idx;
- if (!m->entry)
- break;
- if (try_delta(n, m, depth) < 0)
- break;
- }
- idx++;
- if (idx >= window)
- idx = 0;
+ pdata->index[ix] = i + 1;
+ entry++;
}
-
- for (i = 0; i < window; ++i)
- free(array[i].data);
- free(array);
}
-static void prepare_pack(int window, int depth)
+struct object_entry *packlist_find(struct packing_data *pdata,
+ const unsigned char *sha1,
+ uint32_t *index_pos)
{
- get_object_details();
+ uint32_t i;
+ int found;
- if (progress)
- fprintf(stderr, "Packing %d objects", nr_objects);
- sorted_by_type = create_sorted_list(type_size_sort);
- if (window && depth)
- find_deltas(sorted_by_type, window+1, depth);
- if (progress)
- fputc('\n', stderr);
- write_pack_file();
-}
+ if (!pdata->index_size)
+ return NULL;
-static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
-{
- static const char cache[] = "pack-cache/pack-%s.%s";
- char *cached_pack, *cached_idx;
- int ifd, ofd, ifd_ix = -1;
-
- cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
- ifd = open(cached_pack, O_RDONLY);
- if (ifd < 0)
- return 0;
-
- if (!pack_to_stdout) {
- cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
- ifd_ix = open(cached_idx, O_RDONLY);
- if (ifd_ix < 0) {
- close(ifd);
- return 0;
- }
- }
+ i = locate_object_entry_hash(pdata, sha1, &found);
- fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
- sha1_to_hex(sha1));
+ if (index_pos)
+ *index_pos = i;
- if (pack_to_stdout) {
- if (copy_fd(ifd, 1))
- exit(1);
- close(ifd);
- }
- else {
- char name[PATH_MAX];
- snprintf(name, sizeof(name),
- "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
- ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
- if (ofd < 0)
- die("unable to open %s (%s)", name, strerror(errno));
- if (copy_fd(ifd, ofd))
- exit(1);
- close(ifd);
+ if (!found)
+ return NULL;
- snprintf(name, sizeof(name),
- "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
- ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
- if (ofd < 0)
- die("unable to open %s (%s)", name, strerror(errno));
- if (copy_fd(ifd_ix, ofd))
- exit(1);
- close(ifd_ix);
- puts(sha1_to_hex(sha1));
- }
-
- return 1;
+ return &pdata->objects[pdata->index[i] - 1];
}
-int main(int argc, char **argv)
+struct object_entry *packlist_alloc(struct packing_data *pdata,
+ const unsigned char *sha1,
+ uint32_t index_pos)
{
- SHA_CTX ctx;
- char line[PATH_MAX + 20];
- int window = 10, depth = 10, pack_to_stdout = 0;
- struct object_entry **list;
- int i;
- struct timeval prev_tv;
- int eye_candy = 0;
- int eye_candy_incr = 500;
-
-
- setup_git_directory();
-
- for (i = 1; i < argc; i++) {
- const char *arg = argv[i];
+ struct object_entry *new_entry;
- if (*arg == '-') {
- if (!strcmp("--non-empty", arg)) {
- non_empty = 1;
- continue;
- }
- if (!strcmp("--local", arg)) {
- local = 1;
- continue;
- }
- if (!strcmp("--incremental", arg)) {
- incremental = 1;
- continue;
- }
- if (!strncmp("--window=", arg, 9)) {
- char *end;
- window = strtoul(arg+9, &end, 0);
- if (!arg[9] || *end)
- usage(pack_usage);
- continue;
- }
- if (!strncmp("--depth=", arg, 8)) {
- char *end;
- depth = strtoul(arg+8, &end, 0);
- if (!arg[8] || *end)
- usage(pack_usage);
- continue;
- }
- if (!strcmp("--stdout", arg)) {
- pack_to_stdout = 1;
- continue;
- }
- usage(pack_usage);
- }
- if (base_name)
- usage(pack_usage);
- base_name = arg;
+ if (pdata->nr_objects >= pdata->nr_alloc) {
+ pdata->nr_alloc = (pdata->nr_alloc + 1024) * 3 / 2;
+ REALLOC_ARRAY(pdata->objects, pdata->nr_alloc);
}
- if (pack_to_stdout != !base_name)
- usage(pack_usage);
-
- progress = isatty(2);
+ new_entry = pdata->objects + pdata->nr_objects++;
- prepare_packed_git();
- if (progress) {
- fprintf(stderr, "Generating pack...\n");
- gettimeofday(&prev_tv, NULL);
- }
- while (fgets(line, sizeof(line), stdin) != NULL) {
- unsigned int hash;
- char *p;
- unsigned char sha1[20];
+ memset(new_entry, 0, sizeof(*new_entry));
+ hashcpy(new_entry->idx.sha1, sha1);
- if (progress && (eye_candy <= nr_objects)) {
- fprintf(stderr, "Counting objects...%d\r", nr_objects);
- if (eye_candy && (50 <= eye_candy_incr)) {
- struct timeval tv;
- int time_diff;
- gettimeofday(&tv, NULL);
- time_diff = (tv.tv_sec - prev_tv.tv_sec);
- time_diff <<= 10;
- time_diff += (tv.tv_usec - prev_tv.tv_usec);
- if ((1 << 9) < time_diff)
- eye_candy_incr += 50;
- else if (50 < eye_candy_incr)
- eye_candy_incr -= 50;
- }
- eye_candy += eye_candy_incr;
- }
- if (get_sha1_hex(line, sha1))
- die("expected sha1, got garbage:\n %s", line);
- hash = 0;
- p = line+40;
- while (*p) {
- unsigned char c = *p++;
- if (isspace(c))
- continue;
- hash = hash * 11 + c;
- }
- add_object_entry(sha1, hash);
- }
- if (progress)
- fprintf(stderr, "Done counting %d objects.\n", nr_objects);
- if (non_empty && !nr_objects)
- return 0;
-
- sorted_by_sha = create_sorted_list(sha1_sort);
- SHA1_Init(&ctx);
- list = sorted_by_sha;
- for (i = 0; i < nr_objects; i++) {
- struct object_entry *entry = *list++;
- SHA1_Update(&ctx, entry->sha1, 20);
- }
- SHA1_Final(object_list_sha1, &ctx);
+ if (pdata->index_size * 3 <= pdata->nr_objects * 4)
+ rehash_objects(pdata);
+ else
+ pdata->index[index_pos] = pdata->nr_objects;
- if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
- ;
- else {
- prepare_pack(window, depth);
- if (!pack_to_stdout) {
- write_index_file();
- puts(sha1_to_hex(object_list_sha1));
- }
- }
- return 0;
+ return new_entry;
}