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authorMatthias Kestenholz <matthias@spinlock.ch>2006-08-03 15:24:36 (GMT)
committerJunio C Hamano <junkio@cox.net>2006-08-04 06:15:11 (GMT)
commit5d4a60033543e063bc9d77ca957de0187fb58fb3 (patch)
tree582ce28116d8baa3c207feb327ea6b8d81eed671 /builtin-pack-objects.c
parentd6b64ed0f3549f56c4d948dc2c0f12abc52fd6c9 (diff)
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Make git-pack-objects a builtin
Signed-off-by: Matthias Kestenholz <matthias@spinlock.ch> Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'builtin-pack-objects.c')
-rw-r--r--builtin-pack-objects.c1376
1 files changed, 1376 insertions, 0 deletions
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
new file mode 100644
index 0000000..2301cd5
--- /dev/null
+++ b/builtin-pack-objects.c
@@ -0,0 +1,1376 @@
+#include "builtin.h"
+#include "cache.h"
+#include "object.h"
+#include "blob.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree.h"
+#include "delta.h"
+#include "pack.h"
+#include "csum-file.h"
+#include "tree-walk.h"
+#include <sys/time.h>
+#include <signal.h>
+
+static const char pack_usage[] = "git-pack-objects [-q] [--no-reuse-delta] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
+
+struct object_entry {
+ unsigned char sha1[20];
+ unsigned long size; /* uncompressed size */
+ unsigned long offset; /* offset into the final pack file;
+ * nonzero if already written.
+ */
+ unsigned int depth; /* delta depth */
+ unsigned int delta_limit; /* base adjustment for in-pack delta */
+ unsigned int hash; /* name hint hash */
+ enum object_type type;
+ enum object_type in_pack_type; /* could be delta */
+ unsigned long delta_size; /* delta data size (uncompressed) */
+ struct object_entry *delta; /* delta base object */
+ struct packed_git *in_pack; /* already in pack */
+ unsigned int in_pack_offset;
+ struct object_entry *delta_child; /* deltified objects who bases me */
+ struct object_entry *delta_sibling; /* other deltified objects who
+ * uses the same base as me
+ */
+ int preferred_base; /* we do not pack this, but is encouraged to
+ * be used as the base objectto delta huge
+ * objects against.
+ */
+};
+
+/*
+ * Objects we are going to pack are collected in objects array (dynamically
+ * expanded). nr_objects & nr_alloc controls this array. They are stored
+ * in the order we see -- typically rev-list --objects order that gives us
+ * nice "minimum seek" order.
+ *
+ * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
+ * elements in the objects array. The former is used to build the pack
+ * index (lists object names in the ascending order to help offset lookup),
+ * and the latter is used to group similar things together by try_delta()
+ * heuristics.
+ */
+
+static unsigned char object_list_sha1[20];
+static int non_empty = 0;
+static int no_reuse_delta = 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, nr_result = 0;
+static const char *base_name;
+static unsigned char pack_file_sha1[20];
+static int progress = 1;
+static volatile sig_atomic_t progress_update = 0;
+static int window = 10;
+
+/*
+ * The object names in objects array are hashed with this hashtable,
+ * to help looking up the entry by object name. Binary search from
+ * sorted_by_sha is also possible but this was easier to code and faster.
+ * This hashtable is built after all the objects are seen.
+ */
+static int *object_ix = NULL;
+static int object_ix_hashsz = 0;
+
+/*
+ * Pack index for existing packs give us easy access to the offsets into
+ * corresponding pack file where each object's data starts, but the entries
+ * do not store the size of the compressed representation (uncompressed
+ * size is easily available by examining the pack entry header). We build
+ * a hashtable of existing packs (pack_revindex), and keep reverse index
+ * here -- pack index file is sorted by object name mapping to offset; this
+ * pack_revindex[].revindex array is an ordered list of offsets, so if you
+ * know the offset of an object, next offset is where its packed
+ * representation ends.
+ */
+struct pack_revindex {
+ struct packed_git *p;
+ unsigned long *revindex;
+} *pack_revindex = NULL;
+static int pack_revindex_hashsz = 0;
+
+/*
+ * stats
+ */
+static int written = 0;
+static int written_delta = 0;
+static int reused = 0;
+static int reused_delta = 0;
+
+static int pack_revindex_ix(struct packed_git *p)
+{
+ unsigned long ui = (unsigned long)p;
+ int i;
+
+ ui = ui ^ (ui >> 16); /* defeat structure alignment */
+ i = (int)(ui % pack_revindex_hashsz);
+ while (pack_revindex[i].p) {
+ if (pack_revindex[i].p == p)
+ return i;
+ if (++i == pack_revindex_hashsz)
+ i = 0;
+ }
+ return -1 - i;
+}
+
+static void prepare_pack_ix(void)
+{
+ int num;
+ struct packed_git *p;
+ for (num = 0, p = packed_git; p; p = p->next)
+ num++;
+ if (!num)
+ return;
+ pack_revindex_hashsz = num * 11;
+ pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
+ for (p = packed_git; p; p = p->next) {
+ num = pack_revindex_ix(p);
+ num = - 1 - num;
+ pack_revindex[num].p = p;
+ }
+ /* revindex elements are lazily initialized */
+}
+
+static int cmp_offset(const void *a_, const void *b_)
+{
+ unsigned long a = *(unsigned long *) a_;
+ unsigned long b = *(unsigned long *) b_;
+ if (a < b)
+ return -1;
+ else if (a == b)
+ return 0;
+ else
+ return 1;
+}
+
+/*
+ * Ordered list of offsets of objects in the pack.
+ */
+static void prepare_pack_revindex(struct pack_revindex *rix)
+{
+ struct packed_git *p = rix->p;
+ int num_ent = num_packed_objects(p);
+ int i;
+ void *index = p->index_base + 256;
+
+ rix->revindex = xmalloc(sizeof(unsigned long) * (num_ent + 1));
+ for (i = 0; i < num_ent; i++) {
+ unsigned int hl = *((unsigned int *)((char *) index + 24*i));
+ rix->revindex[i] = ntohl(hl);
+ }
+ /* This knows the pack format -- the 20-byte trailer
+ * follows immediately after the last object data.
+ */
+ rix->revindex[num_ent] = p->pack_size - 20;
+ qsort(rix->revindex, num_ent, sizeof(unsigned long), cmp_offset);
+}
+
+static unsigned long find_packed_object_size(struct packed_git *p,
+ unsigned long ofs)
+{
+ int num;
+ int lo, hi;
+ struct pack_revindex *rix;
+ unsigned long *revindex;
+ num = pack_revindex_ix(p);
+ if (num < 0)
+ die("internal error: pack revindex uninitialized");
+ rix = &pack_revindex[num];
+ if (!rix->revindex)
+ prepare_pack_revindex(rix);
+ revindex = rix->revindex;
+ lo = 0;
+ hi = num_packed_objects(p) + 1;
+ do {
+ int mi = (lo + hi) / 2;
+ if (revindex[mi] == ofs) {
+ return revindex[mi+1] - ofs;
+ }
+ else if (ofs < revindex[mi])
+ hi = mi;
+ else
+ lo = mi + 1;
+ } while (lo < hi);
+ die("internal error: pack revindex corrupt");
+}
+
+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)
+{
+ 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;
+}
+
+static unsigned long write_object(struct sha1file *f,
+ struct object_entry *entry)
+{
+ unsigned long size;
+ char type[10];
+ void *buf;
+ unsigned char header[10];
+ unsigned hdrlen, datalen;
+ enum object_type obj_type;
+ int to_reuse = 0;
+
+ if (entry->preferred_base)
+ return 0;
+
+ obj_type = entry->type;
+ if (! entry->in_pack)
+ to_reuse = 0; /* can't reuse what we don't have */
+ else if (obj_type == OBJ_DELTA)
+ to_reuse = 1; /* check_object() decided it for us */
+ else if (obj_type != entry->in_pack_type)
+ to_reuse = 0; /* pack has delta which is unusable */
+ else if (entry->delta)
+ to_reuse = 0; /* we want to pack afresh */
+ else
+ to_reuse = 1; /* we have it in-pack undeltified,
+ * and we do not need to deltify it.
+ */
+
+ if (! to_reuse) {
+ buf = read_sha1_file(entry->sha1, type, &size);
+ 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);
+ if (entry->delta) {
+ buf = delta_against(buf, size, entry);
+ size = entry->delta_size;
+ obj_type = OBJ_DELTA;
+ }
+ /*
+ * 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.
+ */
+ 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);
+ }
+ else {
+ struct packed_git *p = entry->in_pack;
+ use_packed_git(p);
+
+ datalen = find_packed_object_size(p, entry->in_pack_offset);
+ buf = (char *) p->pack_base + entry->in_pack_offset;
+ sha1write(f, buf, datalen);
+ unuse_packed_git(p);
+ hdrlen = 0; /* not really */
+ if (obj_type == OBJ_DELTA)
+ reused_delta++;
+ reused++;
+ }
+ if (obj_type == OBJ_DELTA)
+ written_delta++;
+ written++;
+ 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;
+ struct pack_header hdr;
+ unsigned last_percent = 999;
+ int do_progress = 0;
+
+ if (!base_name)
+ f = sha1fd(1, "<stdout>");
+ else {
+ f = sha1create("%s-%s.%s", base_name,
+ sha1_to_hex(object_list_sha1), "pack");
+ do_progress = progress;
+ }
+ if (do_progress)
+ fprintf(stderr, "Writing %d objects.\n", nr_result);
+
+ hdr.hdr_signature = htonl(PACK_SIGNATURE);
+ hdr.hdr_version = htonl(PACK_VERSION);
+ hdr.hdr_entries = htonl(nr_result);
+ sha1write(f, &hdr, sizeof(hdr));
+ offset = sizeof(hdr);
+ if (!nr_result)
+ goto done;
+ for (i = 0; i < nr_objects; i++) {
+ offset = write_one(f, objects + i, offset);
+ if (do_progress) {
+ unsigned percent = written * 100 / nr_result;
+ if (progress_update || percent != last_percent) {
+ fprintf(stderr, "%4u%% (%u/%u) done\r",
+ percent, written, nr_result);
+ progress_update = 0;
+ last_percent = percent;
+ }
+ }
+ }
+ if (do_progress)
+ fputc('\n', stderr);
+ done:
+ sha1close(f, pack_file_sha1, 1);
+}
+
+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_result;
+ 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_result; 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 locate_object_entry_hash(const unsigned char *sha1)
+{
+ int i;
+ unsigned int ui;
+ memcpy(&ui, sha1, sizeof(unsigned int));
+ i = ui % object_ix_hashsz;
+ while (0 < object_ix[i]) {
+ if (!memcmp(sha1, objects[object_ix[i]-1].sha1, 20))
+ return i;
+ if (++i == object_ix_hashsz)
+ i = 0;
+ }
+ return -1 - i;
+}
+
+static struct object_entry *locate_object_entry(const unsigned char *sha1)
+{
+ int i;
+
+ if (!object_ix_hashsz)
+ return NULL;
+
+ i = locate_object_entry_hash(sha1);
+ if (0 <= i)
+ return &objects[object_ix[i]-1];
+ return NULL;
+}
+
+static void rehash_objects(void)
+{
+ int i;
+ struct object_entry *oe;
+
+ object_ix_hashsz = nr_objects * 3;
+ if (object_ix_hashsz < 1024)
+ object_ix_hashsz = 1024;
+ object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
+ memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
+ for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
+ int ix = locate_object_entry_hash(oe->sha1);
+ if (0 <= ix)
+ continue;
+ ix = -1 - ix;
+ object_ix[ix] = i + 1;
+ }
+}
+
+static unsigned name_hash(const char *name)
+{
+ unsigned char c;
+ unsigned hash = 0;
+
+ /*
+ * This effectively just creates a sortable number from the
+ * last sixteen non-whitespace characters. Last characters
+ * count "most", so things that end in ".c" sort together.
+ */
+ while ((c = *name++) != 0) {
+ if (isspace(c))
+ continue;
+ hash = (hash >> 2) + (c << 24);
+ }
+ return hash;
+}
+
+static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
+{
+ unsigned int idx = nr_objects;
+ struct object_entry *entry;
+ struct packed_git *p;
+ unsigned int found_offset = 0;
+ struct packed_git *found_pack = NULL;
+ int ix, status = 0;
+
+ if (!exclude) {
+ 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 (!found_pack) {
+ found_offset = e.offset;
+ found_pack = e.p;
+ }
+ }
+ }
+ }
+ if ((entry = locate_object_entry(sha1)) != NULL)
+ goto already_added;
+
+ if (idx >= nr_alloc) {
+ unsigned int needed = (idx + 1024) * 3 / 2;
+ objects = xrealloc(objects, needed * sizeof(*entry));
+ nr_alloc = needed;
+ }
+ entry = objects + idx;
+ nr_objects = idx + 1;
+ memset(entry, 0, sizeof(*entry));
+ memcpy(entry->sha1, sha1, 20);
+ entry->hash = hash;
+
+ if (object_ix_hashsz * 3 <= nr_objects * 4)
+ rehash_objects();
+ else {
+ ix = locate_object_entry_hash(entry->sha1);
+ if (0 <= ix)
+ die("internal error in object hashing.");
+ object_ix[-1 - ix] = idx + 1;
+ }
+ status = 1;
+
+ already_added:
+ if (progress_update) {
+ fprintf(stderr, "Counting objects...%d\r", nr_objects);
+ progress_update = 0;
+ }
+ if (exclude)
+ entry->preferred_base = 1;
+ else {
+ if (found_pack) {
+ entry->in_pack = found_pack;
+ entry->in_pack_offset = found_offset;
+ }
+ }
+ return status;
+}
+
+struct pbase_tree_cache {
+ unsigned char sha1[20];
+ int ref;
+ int temporary;
+ void *tree_data;
+ unsigned long tree_size;
+};
+
+static struct pbase_tree_cache *(pbase_tree_cache[256]);
+static int pbase_tree_cache_ix(const unsigned char *sha1)
+{
+ return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
+}
+static int pbase_tree_cache_ix_incr(int ix)
+{
+ return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
+}
+
+static struct pbase_tree {
+ struct pbase_tree *next;
+ /* This is a phony "cache" entry; we are not
+ * going to evict it nor find it through _get()
+ * mechanism -- this is for the toplevel node that
+ * would almost always change with any commit.
+ */
+ struct pbase_tree_cache pcache;
+} *pbase_tree;
+
+static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
+{
+ struct pbase_tree_cache *ent, *nent;
+ void *data;
+ unsigned long size;
+ char type[20];
+ int neigh;
+ int my_ix = pbase_tree_cache_ix(sha1);
+ int available_ix = -1;
+
+ /* pbase-tree-cache acts as a limited hashtable.
+ * your object will be found at your index or within a few
+ * slots after that slot if it is cached.
+ */
+ for (neigh = 0; neigh < 8; neigh++) {
+ ent = pbase_tree_cache[my_ix];
+ if (ent && !memcmp(ent->sha1, sha1, 20)) {
+ ent->ref++;
+ return ent;
+ }
+ else if (((available_ix < 0) && (!ent || !ent->ref)) ||
+ ((0 <= available_ix) &&
+ (!ent && pbase_tree_cache[available_ix])))
+ available_ix = my_ix;
+ if (!ent)
+ break;
+ my_ix = pbase_tree_cache_ix_incr(my_ix);
+ }
+
+ /* Did not find one. Either we got a bogus request or
+ * we need to read and perhaps cache.
+ */
+ data = read_sha1_file(sha1, type, &size);
+ if (!data)
+ return NULL;
+ if (strcmp(type, tree_type)) {
+ free(data);
+ return NULL;
+ }
+
+ /* We need to either cache or return a throwaway copy */
+
+ if (available_ix < 0)
+ ent = NULL;
+ else {
+ ent = pbase_tree_cache[available_ix];
+ my_ix = available_ix;
+ }
+
+ if (!ent) {
+ nent = xmalloc(sizeof(*nent));
+ nent->temporary = (available_ix < 0);
+ }
+ else {
+ /* evict and reuse */
+ free(ent->tree_data);
+ nent = ent;
+ }
+ memcpy(nent->sha1, sha1, 20);
+ nent->tree_data = data;
+ nent->tree_size = size;
+ nent->ref = 1;
+ if (!nent->temporary)
+ pbase_tree_cache[my_ix] = nent;
+ return nent;
+}
+
+static void pbase_tree_put(struct pbase_tree_cache *cache)
+{
+ if (!cache->temporary) {
+ cache->ref--;
+ return;
+ }
+ free(cache->tree_data);
+ free(cache);
+}
+
+static int name_cmp_len(const char *name)
+{
+ int i;
+ for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
+ ;
+ return i;
+}
+
+static void add_pbase_object(struct tree_desc *tree,
+ const char *name,
+ int cmplen,
+ const char *fullname)
+{
+ struct name_entry entry;
+
+ while (tree_entry(tree,&entry)) {
+ unsigned long size;
+ char type[20];
+
+ if (entry.pathlen != cmplen ||
+ memcmp(entry.path, name, cmplen) ||
+ !has_sha1_file(entry.sha1) ||
+ sha1_object_info(entry.sha1, type, &size))
+ continue;
+ if (name[cmplen] != '/') {
+ unsigned hash = name_hash(fullname);
+ add_object_entry(entry.sha1, hash, 1);
+ return;
+ }
+ if (!strcmp(type, tree_type)) {
+ struct tree_desc sub;
+ struct pbase_tree_cache *tree;
+ const char *down = name+cmplen+1;
+ int downlen = name_cmp_len(down);
+
+ tree = pbase_tree_get(entry.sha1);
+ if (!tree)
+ return;
+ sub.buf = tree->tree_data;
+ sub.size = tree->tree_size;
+
+ add_pbase_object(&sub, down, downlen, fullname);
+ pbase_tree_put(tree);
+ }
+ }
+}
+
+static unsigned *done_pbase_paths;
+static int done_pbase_paths_num;
+static int done_pbase_paths_alloc;
+static int done_pbase_path_pos(unsigned hash)
+{
+ int lo = 0;
+ int hi = done_pbase_paths_num;
+ while (lo < hi) {
+ int mi = (hi + lo) / 2;
+ if (done_pbase_paths[mi] == hash)
+ return mi;
+ if (done_pbase_paths[mi] < hash)
+ hi = mi;
+ else
+ lo = mi + 1;
+ }
+ return -lo-1;
+}
+
+static int check_pbase_path(unsigned hash)
+{
+ int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
+ if (0 <= pos)
+ return 1;
+ pos = -pos - 1;
+ if (done_pbase_paths_alloc <= done_pbase_paths_num) {
+ done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
+ done_pbase_paths = xrealloc(done_pbase_paths,
+ done_pbase_paths_alloc *
+ sizeof(unsigned));
+ }
+ done_pbase_paths_num++;
+ if (pos < done_pbase_paths_num)
+ memmove(done_pbase_paths + pos + 1,
+ done_pbase_paths + pos,
+ (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
+ done_pbase_paths[pos] = hash;
+ return 0;
+}
+
+static void add_preferred_base_object(char *name, unsigned hash)
+{
+ struct pbase_tree *it;
+ int cmplen = name_cmp_len(name);
+
+ if (check_pbase_path(hash))
+ return;
+
+ for (it = pbase_tree; it; it = it->next) {
+ if (cmplen == 0) {
+ hash = name_hash("");
+ add_object_entry(it->pcache.sha1, hash, 1);
+ }
+ else {
+ struct tree_desc tree;
+ tree.buf = it->pcache.tree_data;
+ tree.size = it->pcache.tree_size;
+ add_pbase_object(&tree, name, cmplen, name);
+ }
+ }
+}
+
+static void add_preferred_base(unsigned char *sha1)
+{
+ struct pbase_tree *it;
+ void *data;
+ unsigned long size;
+ unsigned char tree_sha1[20];
+
+ data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
+ if (!data)
+ return;
+
+ for (it = pbase_tree; it; it = it->next) {
+ if (!memcmp(it->pcache.sha1, tree_sha1, 20)) {
+ free(data);
+ return;
+ }
+ }
+
+ it = xcalloc(1, sizeof(*it));
+ it->next = pbase_tree;
+ pbase_tree = it;
+
+ memcpy(it->pcache.sha1, tree_sha1, 20);
+ it->pcache.tree_data = data;
+ it->pcache.tree_size = size;
+}
+
+static void check_object(struct object_entry *entry)
+{
+ char type[20];
+
+ if (entry->in_pack && !entry->preferred_base) {
+ unsigned char base[20];
+ unsigned long size;
+ struct object_entry *base_entry;
+
+ /* We want in_pack_type even if we do not reuse delta.
+ * There is no point not reusing non-delta representations.
+ */
+ check_reuse_pack_delta(entry->in_pack,
+ entry->in_pack_offset,
+ base, &size,
+ &entry->in_pack_type);
+
+ /* Check if it is delta, and the base is also an object
+ * we are going to pack. If so we will reuse the existing
+ * delta.
+ */
+ if (!no_reuse_delta &&
+ entry->in_pack_type == OBJ_DELTA &&
+ (base_entry = locate_object_entry(base)) &&
+ (!base_entry->preferred_base)) {
+
+ /* Depth value does not matter - find_deltas()
+ * will never consider reused delta as the
+ * base object to deltify other objects
+ * against, in order to avoid circular deltas.
+ */
+
+ /* uncompressed size of the delta data */
+ entry->size = entry->delta_size = size;
+ entry->delta = base_entry;
+ entry->type = OBJ_DELTA;
+
+ entry->delta_sibling = base_entry->delta_child;
+ base_entry->delta_child = entry;
+
+ return;
+ }
+ /* Otherwise we would do the usual */
+ }
+
+ if (sha1_object_info(entry->sha1, type, &entry->size))
+ die("unable to get type of object %s",
+ sha1_to_hex(entry->sha1));
+
+ if (!strcmp(type, commit_type)) {
+ entry->type = OBJ_COMMIT;
+ } else if (!strcmp(type, tree_type)) {
+ entry->type = OBJ_TREE;
+ } else if (!strcmp(type, blob_type)) {
+ entry->type = OBJ_BLOB;
+ } else if (!strcmp(type, tag_type)) {
+ entry->type = OBJ_TAG;
+ } else
+ die("unable to pack object %s of type %s",
+ sha1_to_hex(entry->sha1), type);
+}
+
+static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
+{
+ struct object_entry *child = me->delta_child;
+ unsigned int m = n;
+ while (child) {
+ unsigned int c = check_delta_limit(child, n + 1);
+ if (m < c)
+ m = c;
+ child = child->delta_sibling;
+ }
+ return m;
+}
+
+static void get_object_details(void)
+{
+ int i;
+ struct object_entry *entry;
+
+ prepare_pack_ix();
+ for (i = 0, entry = objects; i < nr_objects; i++, entry++)
+ check_object(entry);
+
+ if (nr_objects == nr_result) {
+ /*
+ * Depth of objects that depend on the entry -- this
+ * is subtracted from depth-max to break too deep
+ * delta chain because of delta data reusing.
+ * However, we loosen this restriction when we know we
+ * are creating a thin pack -- it will have to be
+ * expanded on the other end anyway, so do not
+ * artificially cut the delta chain and let it go as
+ * deep as it wants.
+ */
+ for (i = 0, entry = objects; i < nr_objects; i++, entry++)
+ if (!entry->delta && entry->delta_child)
+ entry->delta_limit =
+ check_delta_limit(entry, 1);
+ }
+}
+
+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;
+}
+
+static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
+{
+ return memcmp(a->sha1, b->sha1, 20);
+}
+
+static struct object_entry **create_final_object_list(void)
+{
+ struct object_entry **list;
+ int i, j;
+
+ for (i = nr_result = 0; i < nr_objects; i++)
+ if (!objects[i].preferred_base)
+ nr_result++;
+ list = xmalloc(nr_result * sizeof(struct object_entry *));
+ for (i = j = 0; i < nr_objects; i++) {
+ if (!objects[i].preferred_base)
+ list[j++] = objects + i;
+ }
+ current_sort = sha1_sort;
+ qsort(list, nr_result, sizeof(struct object_entry *), sort_comparator);
+ return list;
+}
+
+static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
+{
+ 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->preferred_base < b->preferred_base)
+ return -1;
+ if (a->preferred_base > b->preferred_base)
+ return 1;
+ if (a->size < b->size)
+ return -1;
+ if (a->size > b->size)
+ return 1;
+ return a < b ? -1 : (a > b);
+}
+
+struct unpacked {
+ struct object_entry *entry;
+ void *data;
+ struct delta_index *index;
+};
+
+/*
+ * 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 *trg, struct unpacked *src,
+ unsigned max_depth)
+{
+ struct object_entry *trg_entry = trg->entry;
+ struct object_entry *src_entry = src->entry;
+ unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
+ char type[10];
+ void *delta_buf;
+
+ /* Don't bother doing diffs between different types */
+ if (trg_entry->type != src_entry->type)
+ return -1;
+
+ /* We do not compute delta to *create* objects we are not
+ * going to pack.
+ */
+ if (trg_entry->preferred_base)
+ return -1;
+
+ /*
+ * We do not bother to try a delta that we discarded
+ * on an earlier try, but only when reusing delta data.
+ */
+ if (!no_reuse_delta && trg_entry->in_pack &&
+ trg_entry->in_pack == src_entry->in_pack)
+ return 0;
+
+ /*
+ * If the current object is at pack edge, take the depth the
+ * objects that depend on the current object into account --
+ * otherwise they would become too deep.
+ */
+ if (trg_entry->delta_child) {
+ if (max_depth <= trg_entry->delta_limit)
+ return 0;
+ max_depth -= trg_entry->delta_limit;
+ }
+ if (src_entry->depth >= max_depth)
+ return 0;
+
+ /* Now some size filtering heuristics. */
+ trg_size = trg_entry->size;
+ max_size = trg_size/2 - 20;
+ max_size = max_size * (max_depth - src_entry->depth) / max_depth;
+ if (max_size == 0)
+ return 0;
+ if (trg_entry->delta && trg_entry->delta_size <= max_size)
+ max_size = trg_entry->delta_size-1;
+ src_size = src_entry->size;
+ sizediff = src_size < trg_size ? trg_size - src_size : 0;
+ if (sizediff >= max_size)
+ return 0;
+
+ /* Load data if not already done */
+ if (!trg->data) {
+ trg->data = read_sha1_file(trg_entry->sha1, type, &sz);
+ if (sz != trg_size)
+ die("object %s inconsistent object length (%lu vs %lu)",
+ sha1_to_hex(trg_entry->sha1), sz, trg_size);
+ }
+ if (!src->data) {
+ src->data = read_sha1_file(src_entry->sha1, type, &sz);
+ if (sz != src_size)
+ die("object %s inconsistent object length (%lu vs %lu)",
+ sha1_to_hex(src_entry->sha1), sz, src_size);
+ }
+ if (!src->index) {
+ src->index = create_delta_index(src->data, src_size);
+ if (!src->index)
+ die("out of memory");
+ }
+
+ delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
+ if (!delta_buf)
+ return 0;
+
+ trg_entry->delta = src_entry;
+ trg_entry->delta_size = delta_size;
+ trg_entry->depth = src_entry->depth + 1;
+ free(delta_buf);
+ return 1;
+}
+
+static void progress_interval(int signum)
+{
+ progress_update = 1;
+}
+
+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);
+ unsigned processed = 0;
+ unsigned last_percent = 999;
+
+ memset(array, 0, array_size);
+ i = nr_objects;
+ idx = 0;
+ if (progress)
+ fprintf(stderr, "Deltifying %d objects.\n", nr_result);
+
+ while (--i >= 0) {
+ struct object_entry *entry = list[i];
+ struct unpacked *n = array + idx;
+ int j;
+
+ if (!entry->preferred_base)
+ processed++;
+
+ if (progress) {
+ unsigned percent = processed * 100 / nr_result;
+ if (percent != last_percent || progress_update) {
+ fprintf(stderr, "%4u%% (%u/%u) done\r",
+ percent, processed, nr_result);
+ progress_update = 0;
+ last_percent = percent;
+ }
+ }
+
+ if (entry->delta)
+ /* This happens if we decided to reuse existing
+ * delta from a pack. "!no_reuse_delta &&" is implied.
+ */
+ continue;
+
+ if (entry->size < 50)
+ continue;
+ free_delta_index(n->index);
+ n->index = NULL;
+ free(n->data);
+ n->data = NULL;
+ n->entry = entry;
+
+ 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;
+ }
+ /* if we made n a delta, and if n is already at max
+ * depth, leaving it in the window is pointless. we
+ * should evict it first.
+ */
+ if (entry->delta && depth <= entry->depth)
+ continue;
+
+ idx++;
+ if (idx >= window)
+ idx = 0;
+ }
+
+ if (progress)
+ fputc('\n', stderr);
+
+ for (i = 0; i < window; ++i) {
+ free_delta_index(array[i].index);
+ free(array[i].data);
+ }
+ free(array);
+}
+
+static void prepare_pack(int window, int depth)
+{
+ get_object_details();
+ sorted_by_type = create_sorted_list(type_size_sort);
+ if (window && depth)
+ find_deltas(sorted_by_type, window+1, depth);
+}
+
+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;
+ }
+ }
+
+ if (progress)
+ fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
+ sha1_to_hex(sha1));
+
+ 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);
+
+ 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;
+}
+
+static void setup_progress_signal(void)
+{
+ struct sigaction sa;
+ struct itimerval v;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = progress_interval;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART;
+ sigaction(SIGALRM, &sa, NULL);
+
+ v.it_interval.tv_sec = 1;
+ v.it_interval.tv_usec = 0;
+ v.it_value = v.it_interval;
+ setitimer(ITIMER_REAL, &v, NULL);
+}
+
+static int git_pack_config(const char *k, const char *v)
+{
+ if(!strcmp(k, "pack.window")) {
+ window = git_config_int(k, v);
+ return 0;
+ }
+ return git_default_config(k, v);
+}
+
+int cmd_pack_objects(int argc, const char **argv, const char *prefix)
+{
+ SHA_CTX ctx;
+ char line[40 + 1 + PATH_MAX + 2];
+ int depth = 10, pack_to_stdout = 0;
+ struct object_entry **list;
+ int num_preferred_base = 0;
+ int i;
+
+ git_config(git_pack_config);
+
+ progress = isatty(2);
+ for (i = 1; i < argc; i++) {
+ const char *arg = argv[i];
+
+ if (*arg == '-') {
+ if (!strcmp("--non-empty", arg)) {
+ non_empty = 1;
+ continue;
+ }
+ if (!strcmp("--local", arg)) {
+ local = 1;
+ continue;
+ }
+ if (!strcmp("--progress", arg)) {
+ progress = 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("--progress", arg)) {
+ progress = 1;
+ continue;
+ }
+ if (!strcmp("-q", arg)) {
+ progress = 0;
+ continue;
+ }
+ if (!strcmp("--no-reuse-delta", arg)) {
+ no_reuse_delta = 1;
+ continue;
+ }
+ if (!strcmp("--stdout", arg)) {
+ pack_to_stdout = 1;
+ continue;
+ }
+ usage(pack_usage);
+ }
+ if (base_name)
+ usage(pack_usage);
+ base_name = arg;
+ }
+
+ if (pack_to_stdout != !base_name)
+ usage(pack_usage);
+
+ prepare_packed_git();
+
+ if (progress) {
+ fprintf(stderr, "Generating pack...\n");
+ setup_progress_signal();
+ }
+
+ for (;;) {
+ unsigned char sha1[20];
+ unsigned hash;
+
+ if (!fgets(line, sizeof(line), stdin)) {
+ if (feof(stdin))
+ break;
+ if (!ferror(stdin))
+ die("fgets returned NULL, not EOF, not error!");
+ if (errno != EINTR)
+ die("fgets: %s", strerror(errno));
+ clearerr(stdin);
+ continue;
+ }
+
+ if (line[0] == '-') {
+ if (get_sha1_hex(line+1, sha1))
+ die("expected edge sha1, got garbage:\n %s",
+ line+1);
+ if (num_preferred_base++ < window)
+ add_preferred_base(sha1);
+ continue;
+ }
+ if (get_sha1_hex(line, sha1))
+ die("expected sha1, got garbage:\n %s", line);
+ hash = name_hash(line+41);
+ add_preferred_base_object(line+41, hash);
+ add_object_entry(sha1, hash, 0);
+ }
+ if (progress)
+ fprintf(stderr, "Done counting %d objects.\n", nr_objects);
+ sorted_by_sha = create_final_object_list();
+ if (non_empty && !nr_result)
+ return 0;
+
+ SHA1_Init(&ctx);
+ list = sorted_by_sha;
+ for (i = 0; i < nr_result; i++) {
+ struct object_entry *entry = *list++;
+ SHA1_Update(&ctx, entry->sha1, 20);
+ }
+ SHA1_Final(object_list_sha1, &ctx);
+ if (progress && (nr_objects != nr_result))
+ fprintf(stderr, "Result has %d objects.\n", nr_result);
+
+ if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
+ ;
+ else {
+ if (nr_result)
+ prepare_pack(window, depth);
+ if (progress && pack_to_stdout) {
+ /* the other end usually displays progress itself */
+ struct itimerval v = {{0,},};
+ setitimer(ITIMER_REAL, &v, NULL);
+ signal(SIGALRM, SIG_IGN );
+ progress_update = 0;
+ }
+ write_pack_file();
+ if (!pack_to_stdout) {
+ write_index_file();
+ puts(sha1_to_hex(object_list_sha1));
+ }
+ }
+ if (progress)
+ fprintf(stderr, "Total %d, written %d (delta %d), reused %d (delta %d)\n",
+ nr_result, written, written_delta, reused, reused_delta);
+ return 0;
+}