Revert "Allow branch.*.merge to talk about remote tracking branches."
[gitweb.git] / builtin-pack-objects.c
index 2301cd5c0f0e6d7a1dc662b9c352f844e2dce027..3824ee33acb2f984419ab79c2f3ecc306d3e5ea5 100644 (file)
@@ -9,10 +9,16 @@
 #include "pack.h"
 #include "csum-file.h"
 #include "tree-walk.h"
-#include <sys/time.h>
-#include <signal.h>
+#include "diff.h"
+#include "revision.h"
+#include "list-objects.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";
+static const char pack_usage[] = "\
+git-pack-objects [{ -q | --progress | --all-progress }] \n\
+       [--local] [--incremental] [--window=N] [--depth=N] \n\
+       [--no-reuse-delta] [--delta-base-offset] [--non-empty] \n\
+       [--revs [--unpacked | --all]*] [--reflog] [--stdout | base-name] \n\
+       [<ref-list | <object-list]";
 
 struct object_entry {
        unsigned char sha1[20];
@@ -26,6 +32,7 @@ struct object_entry {
        enum object_type type;
        enum object_type in_pack_type;  /* could be delta */
        unsigned long delta_size;       /* delta data size (uncompressed) */
+#define in_pack_header_size delta_size /* only when reusing pack data */
        struct object_entry *delta;     /* delta base object */
        struct packed_git *in_pack;     /* already in pack */
        unsigned int in_pack_offset;
@@ -53,18 +60,22 @@ struct object_entry {
  */
 
 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 int non_empty;
+static int no_reuse_delta;
+static int local;
+static int incremental;
+static int allow_ofs_delta;
+
 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 struct object_entry *objects;
+static int nr_objects, nr_alloc, nr_result;
 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 volatile sig_atomic_t progress_update;
 static int window = 10;
+static int pack_to_stdout;
+static int num_preferred_base;
 
 /*
  * The object names in objects array are hashed with this hashtable,
@@ -72,33 +83,41 @@ static int window = 10;
  * 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;
+static int *object_ix;
+static int object_ix_hashsz;
 
 /*
  * 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.
+ * size is easily available by examining the pack entry header).  It is
+ * also rather expensive to find the sha1 for an object given its offset.
+ *
+ * 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 a list of offset/index_nr pairs
+ * ordered by offset, so if you know the offset of an object, next offset
+ * is where its packed representation ends and the index_nr can be used to
+ * get the object sha1 from the main index.
  */
+struct revindex_entry {
+       unsigned int offset;
+       unsigned int nr;
+};
 struct pack_revindex {
        struct packed_git *p;
-       unsigned long *revindex;
-} *pack_revindex = NULL;
-static int pack_revindex_hashsz = 0;
+       struct revindex_entry *revindex;
+};
+static struct  pack_revindex *pack_revindex;
+static int pack_revindex_hashsz;
 
 /*
  * stats
  */
-static int written = 0;
-static int written_delta = 0;
-static int reused = 0;
-static int reused_delta = 0;
+static int written;
+static int written_delta;
+static int reused;
+static int reused_delta;
 
 static int pack_revindex_ix(struct packed_git *p)
 {
@@ -136,14 +155,9 @@ static void prepare_pack_ix(void)
 
 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;
+       const struct revindex_entry *a = a_;
+       const struct revindex_entry *b = b_;
+       return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
 }
 
 /*
@@ -156,25 +170,27 @@ static void prepare_pack_revindex(struct pack_revindex *rix)
        int i;
        void *index = p->index_base + 256;
 
-       rix->revindex = xmalloc(sizeof(unsigned long) * (num_ent + 1));
+       rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
        for (i = 0; i < num_ent; i++) {
                unsigned int hl = *((unsigned int *)((char *) index + 24*i));
-               rix->revindex[i] = ntohl(hl);
+               rix->revindex[i].offset = ntohl(hl);
+               rix->revindex[i].nr = i;
        }
        /* 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);
+       rix->revindex[num_ent].offset = p->pack_size - 20;
+       rix->revindex[num_ent].nr = -1;
+       qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
 }
 
-static unsigned long find_packed_object_size(struct packed_git *p,
-                                            unsigned long ofs)
+static struct revindex_entry * find_packed_object(struct packed_git *p,
+                                                 unsigned int ofs)
 {
        int num;
        int lo, hi;
        struct pack_revindex *rix;
-       unsigned long *revindex;
+       struct revindex_entry *revindex;
        num = pack_revindex_ix(p);
        if (num < 0)
                die("internal error: pack revindex uninitialized");
@@ -186,10 +202,10 @@ static unsigned long find_packed_object_size(struct packed_git *p,
        hi = num_packed_objects(p) + 1;
        do {
                int mi = (lo + hi) / 2;
-               if (revindex[mi] == ofs) {
-                       return revindex[mi+1] - ofs;
+               if (revindex[mi].offset == ofs) {
+                       return revindex + mi;
                }
-               else if (ofs < revindex[mi])
+               else if (ofs < revindex[mi].offset)
                        hi = mi;
                else
                        lo = mi + 1;
@@ -197,6 +213,20 @@ static unsigned long find_packed_object_size(struct packed_git *p,
        die("internal error: pack revindex corrupt");
 }
 
+static unsigned long find_packed_object_size(struct packed_git *p,
+                                            unsigned long ofs)
+{
+       struct revindex_entry *entry = find_packed_object(p, ofs);
+       return entry[1].offset - ofs;
+}
+
+static unsigned char *find_packed_object_name(struct packed_git *p,
+                                             unsigned long ofs)
+{
+       struct revindex_entry *entry = find_packed_object(p, ofs);
+       return (unsigned char *)(p->index_base + 256) + 24 * entry->nr + 4;
+}
+
 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 {
        unsigned long othersize, delta_size;
@@ -227,7 +257,7 @@ static int encode_header(enum object_type type, unsigned long size, unsigned cha
        int n = 1;
        unsigned char c;
 
-       if (type < OBJ_COMMIT || type > OBJ_DELTA)
+       if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
                die("bad type %d", type);
 
        c = (type << 4) | (size & 15);
@@ -242,6 +272,105 @@ static int encode_header(enum object_type type, unsigned long size, unsigned cha
        return n;
 }
 
+/*
+ * we are going to reuse the existing object data as is.  make
+ * sure it is not corrupt.
+ */
+static int check_pack_inflate(struct packed_git *p,
+               struct pack_window **w_curs,
+               unsigned long offset,
+               unsigned long len,
+               unsigned long expect)
+{
+       z_stream stream;
+       unsigned char fakebuf[4096], *in;
+       int st;
+
+       memset(&stream, 0, sizeof(stream));
+       inflateInit(&stream);
+       do {
+               in = use_pack(p, w_curs, offset, &stream.avail_in);
+               stream.next_in = in;
+               stream.next_out = fakebuf;
+               stream.avail_out = sizeof(fakebuf);
+               st = inflate(&stream, Z_FINISH);
+               offset += stream.next_in - in;
+       } while (st == Z_OK || st == Z_BUF_ERROR);
+       inflateEnd(&stream);
+       return (st == Z_STREAM_END &&
+               stream.total_out == expect &&
+               stream.total_in == len) ? 0 : -1;
+}
+
+static void copy_pack_data(struct sha1file *f,
+               struct packed_git *p,
+               struct pack_window **w_curs,
+               unsigned long offset,
+               unsigned long len)
+{
+       unsigned char *in;
+       unsigned int avail;
+
+       while (len) {
+               in = use_pack(p, w_curs, offset, &avail);
+               if (avail > len)
+                       avail = len;
+               sha1write(f, in, avail);
+               offset += avail;
+               len -= avail;
+       }
+}
+
+static int check_loose_inflate(unsigned char *data, unsigned long len, unsigned long expect)
+{
+       z_stream stream;
+       unsigned char fakebuf[4096];
+       int st;
+
+       memset(&stream, 0, sizeof(stream));
+       stream.next_in = data;
+       stream.avail_in = len;
+       stream.next_out = fakebuf;
+       stream.avail_out = sizeof(fakebuf);
+       inflateInit(&stream);
+
+       while (1) {
+               st = inflate(&stream, Z_FINISH);
+               if (st == Z_STREAM_END || st == Z_OK) {
+                       st = (stream.total_out == expect &&
+                             stream.total_in == len) ? 0 : -1;
+                       break;
+               }
+               if (st != Z_BUF_ERROR) {
+                       st = -1;
+                       break;
+               }
+               stream.next_out = fakebuf;
+               stream.avail_out = sizeof(fakebuf);
+       }
+       inflateEnd(&stream);
+       return st;
+}
+
+static int revalidate_loose_object(struct object_entry *entry,
+                                  unsigned char *map,
+                                  unsigned long mapsize)
+{
+       /* we already know this is a loose object with new type header. */
+       enum object_type type;
+       unsigned long size, used;
+
+       if (pack_to_stdout)
+               return 0;
+
+       used = unpack_object_header_gently(map, mapsize, &type, &size);
+       if (!used)
+               return -1;
+       map += used;
+       mapsize -= used;
+       return check_loose_inflate(map, mapsize, size);
+}
+
 static unsigned long write_object(struct sha1file *f,
                                  struct object_entry *entry)
 {
@@ -253,13 +382,10 @@ static unsigned long write_object(struct sha1file *f,
        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)
+       else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_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 */
@@ -270,7 +396,26 @@ static unsigned long write_object(struct sha1file *f,
                                 * and we do not need to deltify it.
                                 */
 
-       if (! to_reuse) {
+       if (!entry->in_pack && !entry->delta) {
+               unsigned char *map;
+               unsigned long mapsize;
+               map = map_sha1_file(entry->sha1, &mapsize);
+               if (map && !legacy_loose_object(map)) {
+                       /* We can copy straight into the pack file */
+                       if (revalidate_loose_object(entry, map, mapsize))
+                               die("corrupt loose object %s",
+                                   sha1_to_hex(entry->sha1));
+                       sha1write(f, map, mapsize);
+                       munmap(map, mapsize);
+                       written++;
+                       reused++;
+                       return mapsize;
+               }
+               if (map)
+                       munmap(map, mapsize);
+       }
+
+       if (!to_reuse) {
                buf = read_sha1_file(entry->sha1, type, &size);
                if (!buf)
                        die("unable to read %s", sha1_to_hex(entry->sha1));
@@ -280,18 +425,35 @@ static unsigned long write_object(struct sha1file *f,
                if (entry->delta) {
                        buf = delta_against(buf, size, entry);
                        size = entry->delta_size;
-                       obj_type = OBJ_DELTA;
+                       obj_type = (allow_ofs_delta && entry->delta->offset) ?
+                               OBJ_OFS_DELTA : OBJ_REF_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.
+                * more bytes of length.
                 */
                hdrlen = encode_header(obj_type, size, header);
                sha1write(f, header, hdrlen);
 
-               if (entry->delta) {
-                       sha1write(f, entry->delta, 20);
+               if (obj_type == OBJ_OFS_DELTA) {
+                       /*
+                        * Deltas with relative base contain an additional
+                        * encoding of the relative offset for the delta
+                        * base from this object's position in the pack.
+                        */
+                       unsigned long ofs = entry->offset - entry->delta->offset;
+                       unsigned pos = sizeof(header) - 1;
+                       header[pos] = ofs & 127;
+                       while (ofs >>= 7)
+                               header[--pos] = 128 | (--ofs & 127);
+                       sha1write(f, header + pos, sizeof(header) - pos);
+                       hdrlen += sizeof(header) - pos;
+               } else if (obj_type == OBJ_REF_DELTA) {
+                       /*
+                        * Deltas with a base reference contain
+                        * an additional 20 bytes for the base sha1.
+                        */
+                       sha1write(f, entry->delta->sha1, 20);
                        hdrlen += 20;
                }
                datalen = sha1write_compressed(f, buf, size);
@@ -299,18 +461,40 @@ static unsigned long write_object(struct sha1file *f,
        }
        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)
+               struct pack_window *w_curs = NULL;
+               unsigned long offset;
+
+               if (entry->delta) {
+                       obj_type = (allow_ofs_delta && entry->delta->offset) ?
+                               OBJ_OFS_DELTA : OBJ_REF_DELTA;
                        reused_delta++;
+               }
+               hdrlen = encode_header(obj_type, entry->size, header);
+               sha1write(f, header, hdrlen);
+               if (obj_type == OBJ_OFS_DELTA) {
+                       unsigned long ofs = entry->offset - entry->delta->offset;
+                       unsigned pos = sizeof(header) - 1;
+                       header[pos] = ofs & 127;
+                       while (ofs >>= 7)
+                               header[--pos] = 128 | (--ofs & 127);
+                       sha1write(f, header + pos, sizeof(header) - pos);
+                       hdrlen += sizeof(header) - pos;
+               } else if (obj_type == OBJ_REF_DELTA) {
+                       sha1write(f, entry->delta->sha1, 20);
+                       hdrlen += 20;
+               }
+
+               offset = entry->in_pack_offset + entry->in_pack_header_size;
+               datalen = find_packed_object_size(p, entry->in_pack_offset)
+                               - entry->in_pack_header_size;
+               if (!pack_to_stdout && check_pack_inflate(p, &w_curs,
+                               offset, datalen, entry->size))
+                       die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
+               copy_pack_data(f, p, &w_curs, offset, datalen);
+               unuse_pack(&w_curs);
                reused++;
        }
-       if (obj_type == OBJ_DELTA)
+       if (entry->delta)
                written_delta++;
        written++;
        return hdrlen + datalen;
@@ -320,17 +504,16 @@ static unsigned long write_one(struct sha1file *f,
                               struct object_entry *e,
                               unsigned long offset)
 {
-       if (e->offset)
+       if (e->offset || e->preferred_base)
                /* 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 we are deltified, write out its base object first. */
        if (e->delta)
                offset = write_one(f, e->delta, offset);
-       return offset;
+       e->offset = offset;
+       return offset + write_object(f, e);
 }
 
 static void write_pack_file(void)
@@ -340,15 +523,15 @@ static void write_pack_file(void)
        unsigned long offset;
        struct pack_header hdr;
        unsigned last_percent = 999;
-       int do_progress = 0;
+       int do_progress = progress;
 
-       if (!base_name)
+       if (!base_name) {
                f = sha1fd(1, "<stdout>");
-       else {
+               do_progress >>= 1;
+       }
+       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);
 
@@ -374,6 +557,8 @@ static void write_pack_file(void)
        if (do_progress)
                fputc('\n', stderr);
  done:
+       if (written != nr_result)
+               die("wrote %d objects while expecting %d", written, nr_result);
        sha1close(f, pack_file_sha1, 1);
 }
 
@@ -384,7 +569,7 @@ static void write_index_file(void)
                                        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];
+       uint32_t array[256];
 
        /*
         * Write the first-level table (the list is sorted,
@@ -402,7 +587,7 @@ static void write_index_file(void)
                array[i] = htonl(next - sorted_by_sha);
                list = next;
        }
-       sha1write(f, array, 256 * sizeof(int));
+       sha1write(f, array, 256 * 4);
 
        /*
         * Write the actual SHA1 entries..
@@ -410,7 +595,7 @@ static void write_index_file(void)
        list = sorted_by_sha;
        for (i = 0; i < nr_result; i++) {
                struct object_entry *entry = *list++;
-               unsigned int offset = htonl(entry->offset);
+               uint32_t offset = htonl(entry->offset);
                sha1write(f, &offset, 4);
                sha1write(f, entry->sha1, 20);
        }
@@ -425,7 +610,7 @@ static int locate_object_entry_hash(const unsigned char *sha1)
        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))
+               if (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
                        return i;
                if (++i == object_ix_hashsz)
                        i = 0;
@@ -494,15 +679,15 @@ static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclud
 
        if (!exclude) {
                for (p = packed_git; p; p = p->next) {
-                       struct pack_entry e;
-                       if (find_pack_entry_one(sha1, &e, p)) {
+                       unsigned long offset = find_pack_entry_one(sha1, p);
+                       if (offset) {
                                if (incremental)
                                        return 0;
                                if (local && !p->pack_local)
                                        return 0;
                                if (!found_pack) {
-                                       found_offset = e.offset;
-                                       found_pack = e.p;
+                                       found_offset = offset;
+                                       found_pack = p;
                                }
                        }
                }
@@ -518,7 +703,7 @@ static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclud
        entry = objects + idx;
        nr_objects = idx + 1;
        memset(entry, 0, sizeof(*entry));
-       memcpy(entry->sha1, sha1, 20);
+       hashcpy(entry->sha1, sha1);
        entry->hash = hash;
 
        if (object_ix_hashsz * 3 <= nr_objects * 4)
@@ -591,7 +776,7 @@ static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
         */
        for (neigh = 0; neigh < 8; neigh++) {
                ent = pbase_tree_cache[my_ix];
-               if (ent && !memcmp(ent->sha1, sha1, 20)) {
+               if (ent && !hashcmp(ent->sha1, sha1)) {
                        ent->ref++;
                        return ent;
                }
@@ -633,7 +818,7 @@ static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
                free(ent->tree_data);
                nent = ent;
        }
-       memcpy(nent->sha1, sha1, 20);
+       hashcpy(nent->sha1, sha1);
        nent->tree_data = data;
        nent->tree_size = size;
        nent->ref = 1;
@@ -739,7 +924,7 @@ static int check_pbase_path(unsigned hash)
        return 0;
 }
 
-static void add_preferred_base_object(char *name, unsigned hash)
+static void add_preferred_base_object(const char *name, unsigned hash)
 {
        struct pbase_tree *it;
        int cmplen = name_cmp_len(name);
@@ -768,12 +953,15 @@ static void add_preferred_base(unsigned char *sha1)
        unsigned long size;
        unsigned char tree_sha1[20];
 
+       if (window <= num_preferred_base++)
+               return;
+
        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)) {
+               if (!hashcmp(it->pcache.sha1, tree_sha1)) {
                        free(data);
                        return;
                }
@@ -783,7 +971,7 @@ static void add_preferred_base(unsigned char *sha1)
        it->next = pbase_tree;
        pbase_tree = it;
 
-       memcpy(it->pcache.sha1, tree_sha1, 20);
+       hashcpy(it->pcache.sha1, tree_sha1);
        it->pcache.tree_data = data;
        it->pcache.tree_size = size;
 }
@@ -793,26 +981,67 @@ 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;
+               struct packed_git *p = entry->in_pack;
+               struct pack_window *w_curs = NULL;
+               unsigned long left = p->pack_size - entry->in_pack_offset;
+               unsigned long size, used;
+               unsigned char *buf;
+               struct object_entry *base_entry = NULL;
+
+               buf = use_pack(p, &w_curs, entry->in_pack_offset, NULL);
 
                /* 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);
+               used = unpack_object_header_gently(buf, left,
+                                                  &entry->in_pack_type, &size);
 
                /* 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)) {
+               if (!no_reuse_delta) {
+                       unsigned char c, *base_name;
+                       unsigned long ofs;
+                       unsigned long used_0;
+                       /* there is at least 20 bytes left in the pack */
+                       switch (entry->in_pack_type) {
+                       case OBJ_REF_DELTA:
+                               base_name = use_pack(p, &w_curs,
+                                       entry->in_pack_offset + used, NULL);
+                               used += 20;
+                               break;
+                       case OBJ_OFS_DELTA:
+                               buf = use_pack(p, &w_curs,
+                                       entry->in_pack_offset + used, NULL);
+                               used_0 = 0;
+                               c = buf[used_0++];
+                               ofs = c & 127;
+                               while (c & 128) {
+                                       ofs += 1;
+                                       if (!ofs || ofs & ~(~0UL >> 7))
+                                               die("delta base offset overflow in pack for %s",
+                                                   sha1_to_hex(entry->sha1));
+                                       c = buf[used_0++];
+                                       ofs = (ofs << 7) + (c & 127);
+                               }
+                               if (ofs >= entry->in_pack_offset)
+                                       die("delta base offset out of bound for %s",
+                                           sha1_to_hex(entry->sha1));
+                               ofs = entry->in_pack_offset - ofs;
+                               base_name = find_packed_object_name(p, ofs);
+                               used += used_0;
+                               break;
+                       default:
+                               base_name = NULL;
+                       }
+                       if (base_name)
+                               base_entry = locate_object_entry(base_name);
+               }
+               unuse_pack(&w_curs);
+               entry->in_pack_header_size = used;
+
+               if (base_entry) {
 
                        /* Depth value does not matter - find_deltas()
                         * will never consider reused delta as the
@@ -821,9 +1050,9 @@ static void check_object(struct object_entry *entry)
                         */
 
                        /* uncompressed size of the delta data */
-                       entry->size = entry->delta_size = size;
+                       entry->size = size;
                        entry->delta = base_entry;
-                       entry->type = OBJ_DELTA;
+                       entry->type = entry->in_pack_type;
 
                        entry->delta_sibling = base_entry->delta_child;
                        base_entry->delta_child = entry;
@@ -915,7 +1144,7 @@ static struct object_entry **create_sorted_list(entry_sort_t sort)
 
 static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
 {
-       return memcmp(a->sha1, b->sha1, 20);
+       return hashcmp(a->sha1, b->sha1);
 }
 
 static struct object_entry **create_final_object_list(void)
@@ -995,7 +1224,9 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
         * 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)
+           trg_entry->in_pack == src_entry->in_pack &&
+           trg_entry->in_pack_type != OBJ_REF_DELTA &&
+           trg_entry->in_pack_type != OBJ_OFS_DELTA)
                return 0;
 
        /*
@@ -1147,7 +1378,7 @@ static void prepare_pack(int window, int depth)
                find_deltas(sorted_by_type, window+1, depth);
 }
 
-static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
+static int reuse_cached_pack(unsigned char *sha1)
 {
        static const char cache[] = "pack-cache/pack-%s.%s";
        char *cached_pack, *cached_idx;
@@ -1227,14 +1458,105 @@ static int git_pack_config(const char *k, const char *v)
        return git_default_config(k, v);
 }
 
+static void read_object_list_from_stdin(void)
+{
+       char line[40 + 1 + PATH_MAX + 2];
+       unsigned char sha1[20];
+       unsigned hash;
+
+       for (;;) {
+               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);
+                       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);
+       }
+}
+
+static void show_commit(struct commit *commit)
+{
+       unsigned hash = name_hash("");
+       add_preferred_base_object("", hash);
+       add_object_entry(commit->object.sha1, hash, 0);
+}
+
+static void show_object(struct object_array_entry *p)
+{
+       unsigned hash = name_hash(p->name);
+       add_preferred_base_object(p->name, hash);
+       add_object_entry(p->item->sha1, hash, 0);
+}
+
+static void show_edge(struct commit *commit)
+{
+       add_preferred_base(commit->object.sha1);
+}
+
+static void get_object_list(int ac, const char **av)
+{
+       struct rev_info revs;
+       char line[1000];
+       int flags = 0;
+
+       init_revisions(&revs, NULL);
+       save_commit_buffer = 0;
+       track_object_refs = 0;
+       setup_revisions(ac, av, &revs, NULL);
+
+       while (fgets(line, sizeof(line), stdin) != NULL) {
+               int len = strlen(line);
+               if (line[len - 1] == '\n')
+                       line[--len] = 0;
+               if (!len)
+                       break;
+               if (*line == '-') {
+                       if (!strcmp(line, "--not")) {
+                               flags ^= UNINTERESTING;
+                               continue;
+                       }
+                       die("not a rev '%s'", line);
+               }
+               if (handle_revision_arg(line, &revs, flags, 1))
+                       die("bad revision '%s'", line);
+       }
+
+       prepare_revision_walk(&revs);
+       mark_edges_uninteresting(revs.commits, &revs, show_edge);
+       traverse_commit_list(&revs, show_commit, show_object);
+}
+
 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;
+       int depth = 10;
        struct object_entry **list;
-       int num_preferred_base = 0;
+       int use_internal_rev_list = 0;
+       int thin = 0;
        int i;
+       const char *rp_av[64];
+       int rp_ac;
+
+       rp_av[0] = "pack-objects";
+       rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
+       rp_ac = 2;
 
        git_config(git_pack_config);
 
@@ -1242,63 +1564,104 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
        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 (*arg != '-')
+                       break;
+
+               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("--progress", arg)) {
+                       progress = 1;
+                       continue;
+               }
+               if (!strcmp("--all-progress", arg)) {
+                       progress = 2;
+                       continue;
+               }
+               if (!strcmp("-q", arg)) {
+                       progress = 0;
+                       continue;
+               }
+               if (!strcmp("--no-reuse-delta", arg)) {
+                       no_reuse_delta = 1;
+                       continue;
+               }
+               if (!strcmp("--delta-base-offset", arg)) {
+                       allow_ofs_delta = 1;
+                       continue;
                }
-               if (base_name)
-                       usage(pack_usage);
-               base_name = arg;
+               if (!strcmp("--stdout", arg)) {
+                       pack_to_stdout = 1;
+                       continue;
+               }
+               if (!strcmp("--revs", arg)) {
+                       use_internal_rev_list = 1;
+                       continue;
+               }
+               if (!strcmp("--unpacked", arg) ||
+                   !strncmp("--unpacked=", arg, 11) ||
+                   !strcmp("--reflog", arg) ||
+                   !strcmp("--all", arg)) {
+                       use_internal_rev_list = 1;
+                       if (ARRAY_SIZE(rp_av) - 1 <= rp_ac)
+                               die("too many internal rev-list options");
+                       rp_av[rp_ac++] = arg;
+                       continue;
+               }
+               if (!strcmp("--thin", arg)) {
+                       use_internal_rev_list = 1;
+                       thin = 1;
+                       rp_av[1] = "--objects-edge";
+                       continue;
+               }
+               usage(pack_usage);
        }
 
+       /* Traditionally "pack-objects [options] base extra" failed;
+        * we would however want to take refs parameter that would
+        * have been given to upstream rev-list ourselves, which means
+        * we somehow want to say what the base name is.  So the
+        * syntax would be:
+        *
+        * pack-objects [options] base <refs...>
+        *
+        * in other words, we would treat the first non-option as the
+        * base_name and send everything else to the internal revision
+        * walker.
+        */
+
+       if (!pack_to_stdout)
+               base_name = argv[i++];
+
        if (pack_to_stdout != !base_name)
                usage(pack_usage);
 
+       if (!pack_to_stdout && thin)
+               die("--thin cannot be used to build an indexable pack.");
+
        prepare_packed_git();
 
        if (progress) {
@@ -1306,35 +1669,13 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                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 (!use_internal_rev_list)
+               read_object_list_from_stdin();
+       else {
+               rp_av[rp_ac] = NULL;
+               get_object_list(rp_ac, rp_av);
        }
+
        if (progress)
                fprintf(stderr, "Done counting %d objects.\n", nr_objects);
        sorted_by_sha = create_final_object_list();
@@ -1351,12 +1692,12 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
        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))
+       if (reuse_cached_pack(object_list_sha1))
                ;
        else {
                if (nr_result)
                        prepare_pack(window, depth);
-               if (progress && pack_to_stdout) {
+               if (progress == 1 && pack_to_stdout) {
                        /* the other end usually displays progress itself */
                        struct itimerval v = {{0,},};
                        setitimer(ITIMER_REAL, &v, NULL);
@@ -1370,7 +1711,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                }
        }
        if (progress)
-               fprintf(stderr, "Total %d, written %d (delta %d), reused %d (delta %d)\n",
-                       nr_result, written, written_delta, reused, reused_delta);
+               fprintf(stderr, "Total %d (delta %d), reused %d (delta %d)\n",
+                       written, written_delta, reused, reused_delta);
        return 0;
 }