user-manual: update for new default --track behavior
[gitweb.git] / builtin-pack-objects.c
index 45ac3e482acc1c0f8f2bad043f1ba50019dec505..5e9d1fd86ce5ee18dcb9ace9595b925f7630b6e8 100644 (file)
@@ -1,5 +1,6 @@
 #include "builtin.h"
 #include "cache.h"
+#include "attr.h"
 #include "object.h"
 #include "blob.h"
 #include "commit.h"
 #include "diff.h"
 #include "revision.h"
 #include "list-objects.h"
+#include "progress.h"
 
 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]";
+       [--max-pack-size=N] [--local] [--incremental] \n\
+       [--window=N] [--window-memory=N] [--depth=N] \n\
+       [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
+       [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
+       [--stdout | base-name] [<ref-list | <object-list]";
 
 struct object_entry {
-       unsigned char sha1[20];
+       struct pack_idx_entry idx;
        unsigned long size;     /* uncompressed size */
-       off_t 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) */
-#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 */
        off_t in_pack_offset;
+       struct object_entry *delta;     /* delta base object */
        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.
-                                */
+       void *delta_data;       /* cached delta (uncompressed) */
+       unsigned long delta_size;       /* delta data size (uncompressed) */
+       unsigned int hash;      /* name hint hash */
+       enum object_type type;
+       enum object_type in_pack_type;  /* could be delta */
+       unsigned char in_pack_header_size;
+       unsigned char preferred_base; /* we do not pack this, but is available
+                                      * to be used as the base object to delta
+                                      * objects against.
+                                      */
+       unsigned char no_try_delta;
 };
 
 /*
@@ -51,36 +51,39 @@ struct object_entry {
  * 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 struct object_entry *objects;
+static struct object_entry **written_list;
+static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
 
-static unsigned char object_list_sha1[20];
 static int non_empty;
-static int no_reuse_delta;
+static int no_reuse_delta, no_reuse_object;
 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;
-static uint32_t nr_objects, nr_alloc, nr_result;
+static const char *pack_tmp_name, *idx_tmp_name;
+static char tmpname[PATH_MAX];
 static const char *base_name;
-static unsigned char pack_file_sha1[20];
 static int progress = 1;
-static volatile sig_atomic_t progress_update;
 static int window = 10;
+static uint32_t pack_size_limit;
+static int depth = 50;
 static int pack_to_stdout;
 static int num_preferred_base;
+static struct progress progress_state;
+static int pack_compression_level = Z_DEFAULT_COMPRESSION;
+static int pack_compression_seen;
+
+static unsigned long delta_cache_size = 0;
+static unsigned long max_delta_cache_size = 0;
+static unsigned long cache_max_small_delta_size = 1000;
+
+static unsigned long window_memory_usage = 0;
+static unsigned long window_memory_limit = 0;
 
 /*
  * 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.
+ * to help looking up the entry by object name.
  * This hashtable is built after all the objects are seen.
  */
 static int *object_ix;
@@ -164,17 +167,37 @@ static int cmp_offset(const void *a_, const void *b_)
 static void prepare_pack_revindex(struct pack_revindex *rix)
 {
        struct packed_git *p = rix->p;
-       int num_ent = num_packed_objects(p);
+       int num_ent = p->num_objects;
        int i;
        const char *index = p->index_data;
 
-       index += 4 * 256;
        rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
-       for (i = 0; i < num_ent; i++) {
-               uint32_t hl = *((uint32_t *)(index + 24 * i));
-               rix->revindex[i].offset = ntohl(hl);
-               rix->revindex[i].nr = i;
+       index += 4 * 256;
+
+       if (p->index_version > 1) {
+               const uint32_t *off_32 =
+                       (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
+               const uint32_t *off_64 = off_32 + p->num_objects;
+               for (i = 0; i < num_ent; i++) {
+                       uint32_t off = ntohl(*off_32++);
+                       if (!(off & 0x80000000)) {
+                               rix->revindex[i].offset = off;
+                       } else {
+                               rix->revindex[i].offset =
+                                       ((uint64_t)ntohl(*off_64++)) << 32;
+                               rix->revindex[i].offset |=
+                                       ntohl(*off_64++);
+                       }
+                       rix->revindex[i].nr = i;
+               }
+       } else {
+               for (i = 0; i < num_ent; i++) {
+                       uint32_t hl = *((uint32_t *)(index + 24 * i));
+                       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.
         */
@@ -198,7 +221,7 @@ static struct revindex_entry * find_packed_object(struct packed_git *p,
                prepare_pack_revindex(rix);
        revindex = rix->revindex;
        lo = 0;
-       hi = num_packed_objects(p) + 1;
+       hi = p->num_objects + 1;
        do {
                int mi = (lo + hi) / 2;
                if (revindex[mi].offset == ofs) {
@@ -212,12 +235,6 @@ static struct revindex_entry * find_packed_object(struct packed_git *p,
        die("internal error: pack revindex corrupt");
 }
 
-static off_t find_packed_object_size(struct packed_git *p, off_t ofs)
-{
-       struct revindex_entry *entry = find_packed_object(p, ofs);
-       return entry[1].offset - ofs;
-}
-
 static const unsigned char *find_packed_object_name(struct packed_git *p,
                                                    off_t ofs)
 {
@@ -229,15 +246,15 @@ static void *delta_against(void *buf, unsigned long size, struct object_entry *e
 {
        unsigned long othersize, delta_size;
        enum object_type type;
-       void *otherbuf = read_sha1_file(entry->delta->sha1, &type, &othersize);
+       void *otherbuf = read_sha1_file(entry->delta->idx.sha1, &type, &othersize);
        void *delta_buf;
 
        if (!otherbuf)
-               die("unable to read %s", sha1_to_hex(entry->delta->sha1));
+               die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
         delta_buf = diff_delta(otherbuf, othersize,
                               buf, size, &delta_size, 0);
         if (!delta_buf || delta_size != entry->delta_size)
-               die("delta size changed");
+               die("delta size changed");
         free(buf);
         free(otherbuf);
        return delta_buf;
@@ -300,6 +317,28 @@ static int check_pack_inflate(struct packed_git *p,
                stream.total_in == len) ? 0 : -1;
 }
 
+static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
+                         off_t offset, off_t len, unsigned int nr)
+{
+       const uint32_t *index_crc;
+       uint32_t data_crc = crc32(0, Z_NULL, 0);
+
+       do {
+               unsigned int avail;
+               void *data = use_pack(p, w_curs, offset, &avail);
+               if (avail > len)
+                       avail = len;
+               data_crc = crc32(data_crc, data, avail);
+               offset += avail;
+               len -= avail;
+       } while (len);
+
+       index_crc = p->index_data;
+       index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
+
+       return data_crc != ntohl(*index_crc);
+}
+
 static void copy_pack_data(struct sha1file *f,
                struct packed_git *p,
                struct pack_window **w_curs,
@@ -319,73 +358,45 @@ static void copy_pack_data(struct sha1file *f,
        }
 }
 
-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 off_t write_object(struct sha1file *f,
-                                 struct object_entry *entry)
+static unsigned long write_object(struct sha1file *f,
+                                 struct object_entry *entry,
+                                 off_t write_offset)
 {
        unsigned long size;
        enum object_type type;
        void *buf;
        unsigned char header[10];
+       unsigned char dheader[10];
        unsigned hdrlen;
        off_t datalen;
        enum object_type obj_type;
        int to_reuse = 0;
+       /* write limit if limited packsize and not first object */
+       unsigned long limit = pack_size_limit && nr_written ?
+                               pack_size_limit - write_offset : 0;
+                               /* no if no delta */
+       int usable_delta =      !entry->delta ? 0 :
+                               /* yes if unlimited packfile */
+                               !pack_size_limit ? 1 :
+                               /* no if base written to previous pack */
+                               entry->delta->idx.offset == (off_t)-1 ? 0 :
+                               /* otherwise double-check written to this
+                                * pack,  like we do below
+                                */
+                               entry->delta->idx.offset ? 1 : 0;
+
+       if (!pack_to_stdout)
+               crc32_begin(f);
 
        obj_type = entry->type;
-       if (! entry->in_pack)
+       if (no_reuse_object)
+               to_reuse = 0;   /* explicit */
+       else if (!entry->in_pack)
                to_reuse = 0;   /* can't reuse what we don't have */
        else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
-               to_reuse = 1;   /* check_object() decided it for us */
+                               /* check_object() decided it for us ... */
+               to_reuse = usable_delta;
+                               /* ... but pack split may override that */
        else if (obj_type != entry->in_pack_type)
                to_reuse = 0;   /* pack has delta which is unusable */
        else if (entry->delta)
@@ -395,44 +406,49 @@ static off_t write_object(struct sha1file *f,
                                 * and we do not need to deltify it.
                                 */
 
-       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));
-               if (size != entry->size)
-                       die("object %s size inconsistency (%lu vs %lu)",
-                           sha1_to_hex(entry->sha1), size, entry->size);
-               if (entry->delta) {
+               z_stream stream;
+               unsigned long maxsize;
+               void *out;
+               if (!usable_delta) {
+                       buf = read_sha1_file(entry->idx.sha1, &obj_type, &size);
+                       if (!buf)
+                               die("unable to read %s", sha1_to_hex(entry->idx.sha1));
+               } else if (entry->delta_data) {
+                       size = entry->delta_size;
+                       buf = entry->delta_data;
+                       entry->delta_data = NULL;
+                       obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
+                               OBJ_OFS_DELTA : OBJ_REF_DELTA;
+               } else {
+                       buf = read_sha1_file(entry->idx.sha1, &type, &size);
+                       if (!buf)
+                               die("unable to read %s", sha1_to_hex(entry->idx.sha1));
                        buf = delta_against(buf, size, entry);
                        size = entry->delta_size;
-                       obj_type = (allow_ofs_delta && entry->delta->offset) ?
+                       obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
                }
+               /* compress the data to store and put compressed length in datalen */
+               memset(&stream, 0, sizeof(stream));
+               deflateInit(&stream, pack_compression_level);
+               maxsize = deflateBound(&stream, size);
+               out = xmalloc(maxsize);
+               /* Compress it */
+               stream.next_in = buf;
+               stream.avail_in = size;
+               stream.next_out = out;
+               stream.avail_out = maxsize;
+               while (deflate(&stream, Z_FINISH) == Z_OK)
+                       /* nothing */;
+               deflateEnd(&stream);
+               datalen = stream.total_out;
+               deflateEnd(&stream);
                /*
                 * The object header is a byte of 'type' followed by zero or
                 * more bytes of length.
                 */
                hdrlen = encode_header(obj_type, size, header);
-               sha1write(f, header, hdrlen);
 
                if (obj_type == OBJ_OFS_DELTA) {
                        /*
@@ -440,62 +456,99 @@ static off_t write_object(struct sha1file *f,
                         * encoding of the relative offset for the delta
                         * base from this object's position in the pack.
                         */
-                       off_t ofs = entry->offset - entry->delta->offset;
-                       unsigned pos = sizeof(header) - 1;
-                       header[pos] = ofs & 127;
+                       off_t ofs = entry->idx.offset - entry->delta->idx.offset;
+                       unsigned pos = sizeof(dheader) - 1;
+                       dheader[pos] = ofs & 127;
                        while (ofs >>= 7)
-                               header[--pos] = 128 | (--ofs & 127);
-                       sha1write(f, header + pos, sizeof(header) - pos);
-                       hdrlen += sizeof(header) - pos;
+                               dheader[--pos] = 128 | (--ofs & 127);
+                       if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
+                               free(out);
+                               free(buf);
+                               return 0;
+                       }
+                       sha1write(f, header, hdrlen);
+                       sha1write(f, dheader + pos, sizeof(dheader) - pos);
+                       hdrlen += sizeof(dheader) - 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);
+                       if (limit && hdrlen + 20 + datalen + 20 >= limit) {
+                               free(out);
+                               free(buf);
+                               return 0;
+                       }
+                       sha1write(f, header, hdrlen);
+                       sha1write(f, entry->delta->idx.sha1, 20);
                        hdrlen += 20;
+               } else {
+                       if (limit && hdrlen + datalen + 20 >= limit) {
+                               free(out);
+                               free(buf);
+                               return 0;
+                       }
+                       sha1write(f, header, hdrlen);
                }
-               datalen = sha1write_compressed(f, buf, size);
+               sha1write(f, out, datalen);
+               free(out);
                free(buf);
        }
        else {
                struct packed_git *p = entry->in_pack;
                struct pack_window *w_curs = NULL;
+               struct revindex_entry *revidx;
                off_t offset;
 
                if (entry->delta) {
-                       obj_type = (allow_ofs_delta && entry->delta->offset) ?
+                       obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
                        reused_delta++;
                }
                hdrlen = encode_header(obj_type, entry->size, header);
-               sha1write(f, header, hdrlen);
+               offset = entry->in_pack_offset;
+               revidx = find_packed_object(p, offset);
+               datalen = revidx[1].offset - offset;
+               if (!pack_to_stdout && p->index_version > 1 &&
+                   check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
+                       die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
+               offset += entry->in_pack_header_size;
+               datalen -= entry->in_pack_header_size;
                if (obj_type == OBJ_OFS_DELTA) {
-                       off_t ofs = entry->offset - entry->delta->offset;
-                       unsigned pos = sizeof(header) - 1;
-                       header[pos] = ofs & 127;
+                       off_t ofs = entry->idx.offset - entry->delta->idx.offset;
+                       unsigned pos = sizeof(dheader) - 1;
+                       dheader[pos] = ofs & 127;
                        while (ofs >>= 7)
-                               header[--pos] = 128 | (--ofs & 127);
-                       sha1write(f, header + pos, sizeof(header) - pos);
-                       hdrlen += sizeof(header) - pos;
+                               dheader[--pos] = 128 | (--ofs & 127);
+                       if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
+                               return 0;
+                       sha1write(f, header, hdrlen);
+                       sha1write(f, dheader + pos, sizeof(dheader) - pos);
+                       hdrlen += sizeof(dheader) - pos;
                } else if (obj_type == OBJ_REF_DELTA) {
-                       sha1write(f, entry->delta->sha1, 20);
+                       if (limit && hdrlen + 20 + datalen + 20 >= limit)
+                               return 0;
+                       sha1write(f, header, hdrlen);
+                       sha1write(f, entry->delta->idx.sha1, 20);
                        hdrlen += 20;
+               } else {
+                       if (limit && hdrlen + datalen + 20 >= limit)
+                               return 0;
+                       sha1write(f, header, hdrlen);
                }
 
-               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));
+               if (!pack_to_stdout && p->index_version == 1 &&
+                   check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
+                       die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
                copy_pack_data(f, p, &w_curs, offset, datalen);
                unuse_pack(&w_curs);
                reused++;
        }
-       if (entry->delta)
+       if (usable_delta)
                written_delta++;
        written++;
+       if (!pack_to_stdout)
+               entry->idx.crc32 = crc32_end(f);
        return hdrlen + datalen;
 }
 
@@ -503,103 +556,147 @@ static off_t write_one(struct sha1file *f,
                               struct object_entry *e,
                               off_t offset)
 {
-       if (e->offset || e->preferred_base)
-               /* offset starts from header size and cannot be zero
-                * if it is written already.
-                */
+       unsigned long size;
+
+       /* offset is non zero if object is written already. */
+       if (e->idx.offset || e->preferred_base)
                return offset;
-       /* if we are deltified, write out its base object first. */
-       if (e->delta)
+
+       /* if we are deltified, write out base object first. */
+       if (e->delta) {
                offset = write_one(f, e->delta, offset);
-       e->offset = offset;
-       return offset + write_object(f, e);
+               if (!offset)
+                       return 0;
+       }
+
+       e->idx.offset = offset;
+       size = write_object(f, e, offset);
+       if (!size) {
+               e->idx.offset = 0;
+               return 0;
+       }
+       written_list[nr_written++] = e;
+
+       /* make sure off_t is sufficiently large not to wrap */
+       if (offset > offset + size)
+               die("pack too large for current definition of off_t");
+       return offset + size;
+}
+
+static int open_object_dir_tmp(const char *path)
+{
+    snprintf(tmpname, sizeof(tmpname), "%s/%s", get_object_directory(), path);
+    return mkstemp(tmpname);
 }
 
+/* forward declaration for write_pack_file */
+static int adjust_perm(const char *path, mode_t mode);
+
 static void write_pack_file(void)
 {
-       uint32_t i;
+       uint32_t i = 0, j;
        struct sha1file *f;
-       off_t offset;
+       off_t offset, offset_one, last_obj_offset = 0;
        struct pack_header hdr;
-       unsigned last_percent = 999;
-       int do_progress = progress;
+       int do_progress = progress >> pack_to_stdout;
+       uint32_t nr_remaining = nr_result;
 
-       if (!base_name) {
-               f = sha1fd(1, "<stdout>");
-               do_progress >>= 1;
-       }
-       else
-               f = sha1create("%s-%s.%s", base_name,
-                              sha1_to_hex(object_list_sha1), "pack");
        if (do_progress)
-               fprintf(stderr, "Writing %u 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:
-       if (written != nr_result)
-               die("wrote %u objects while expecting %u", written, nr_result);
-       sha1close(f, pack_file_sha1, 1);
-}
+               start_progress(&progress_state, "Writing %u objects...", "", nr_result);
+       written_list = xmalloc(nr_objects * sizeof(struct object_entry *));
 
-static void write_index_file(void)
-{
-       uint32_t 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;
-       uint32_t array[256];
+       do {
+               unsigned char sha1[20];
+
+               if (pack_to_stdout) {
+                       f = sha1fd(1, "<stdout>");
+               } else {
+                       int fd = open_object_dir_tmp("tmp_pack_XXXXXX");
+                       if (fd < 0)
+                               die("unable to create %s: %s\n", tmpname, strerror(errno));
+                       pack_tmp_name = xstrdup(tmpname);
+                       f = sha1fd(fd, pack_tmp_name);
+               }
 
-       /*
-        * 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)
+               hdr.hdr_signature = htonl(PACK_SIGNATURE);
+               hdr.hdr_version = htonl(PACK_VERSION);
+               hdr.hdr_entries = htonl(nr_remaining);
+               sha1write(f, &hdr, sizeof(hdr));
+               offset = sizeof(hdr);
+               nr_written = 0;
+               for (; i < nr_objects; i++) {
+                       last_obj_offset = offset;
+                       offset_one = write_one(f, objects + i, offset);
+                       if (!offset_one)
                                break;
-                       next++;
+                       offset = offset_one;
+                       if (do_progress)
+                               display_progress(&progress_state, written);
                }
-               array[i] = htonl(next - sorted_by_sha);
-               list = next;
-       }
-       sha1write(f, array, 256 * 4);
 
+               /*
+                * Did we write the wrong # entries in the header?
+                * If so, rewrite it like in fast-import
+                */
+               if (pack_to_stdout || nr_written == nr_remaining) {
+                       sha1close(f, sha1, 1);
+               } else {
+                       sha1close(f, sha1, 0);
+                       fixup_pack_header_footer(f->fd, sha1, pack_tmp_name, nr_written);
+                       close(f->fd);
+               }
+
+               if (!pack_to_stdout) {
+                       mode_t mode = umask(0);
+
+                       umask(mode);
+                       mode = 0444 & ~mode;
+
+                       idx_tmp_name = write_idx_file(NULL,
+                               (struct pack_idx_entry **) written_list, nr_written, sha1);
+                       snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
+                                base_name, sha1_to_hex(sha1));
+                       if (adjust_perm(pack_tmp_name, mode))
+                               die("unable to make temporary pack file readable: %s",
+                                   strerror(errno));
+                       if (rename(pack_tmp_name, tmpname))
+                               die("unable to rename temporary pack file: %s",
+                                   strerror(errno));
+                       snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
+                                base_name, sha1_to_hex(sha1));
+                       if (adjust_perm(idx_tmp_name, mode))
+                               die("unable to make temporary index file readable: %s",
+                                   strerror(errno));
+                       if (rename(idx_tmp_name, tmpname))
+                               die("unable to rename temporary index file: %s",
+                                   strerror(errno));
+                       puts(sha1_to_hex(sha1));
+               }
+
+               /* mark written objects as written to previous pack */
+               for (j = 0; j < nr_written; j++) {
+                       written_list[j]->idx.offset = (off_t)-1;
+               }
+               nr_remaining -= nr_written;
+       } while (nr_remaining && i < nr_objects);
+
+       free(written_list);
+       if (do_progress)
+               stop_progress(&progress_state);
+       if (written != nr_result)
+               die("wrote %u objects while expecting %u", written, nr_result);
        /*
-        * Write the actual SHA1 entries..
+        * We have scanned through [0 ... i).  Since we have written
+        * the correct number of objects,  the remaining [i ... nr_objects)
+        * items must be either already written (due to out-of-order delta base)
+        * or a preferred base.  Count those which are neither and complain if any.
         */
-       list = sorted_by_sha;
-       for (i = 0; i < nr_result; i++) {
-               struct object_entry *entry = *list++;
-               uint32_t offset = htonl(entry->offset);
-               sha1write(f, &offset, 4);
-               sha1write(f, entry->sha1, 20);
+       for (j = 0; i < nr_objects; i++) {
+               struct object_entry *e = objects + i;
+               j += !e->idx.offset && !e->preferred_base;
        }
-       sha1write(f, pack_file_sha1, 20);
-       sha1close(f, NULL, 1);
+       if (j)
+               die("wrote %u objects as expected but %u unwritten", written, j);
 }
 
 static int locate_object_entry_hash(const unsigned char *sha1)
@@ -609,7 +706,7 @@ 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 (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
+               if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
                        return i;
                if (++i == object_ix_hashsz)
                        i = 0;
@@ -641,7 +738,7 @@ static void rehash_objects(void)
        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);
+               int ix = locate_object_entry_hash(oe->idx.sha1);
                if (0 <= ix)
                        continue;
                ix = -1 - ix;
@@ -654,6 +751,9 @@ static unsigned name_hash(const char *name)
        unsigned char c;
        unsigned hash = 0;
 
+       if (!name)
+               return 0;
+
        /*
         * This effectively just creates a sortable number from the
         * last sixteen non-whitespace characters. Last characters
@@ -667,67 +767,96 @@ static unsigned name_hash(const char *name)
        return hash;
 }
 
-static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
+static void setup_delta_attr_check(struct git_attr_check *check)
+{
+       static struct git_attr *attr_delta;
+
+       if (!attr_delta)
+               attr_delta = git_attr("delta", 5);
+
+       check[0].attr = attr_delta;
+}
+
+static int no_try_delta(const char *path)
+{
+       struct git_attr_check check[1];
+
+       setup_delta_attr_check(check);
+       if (git_checkattr(path, ARRAY_SIZE(check), check))
+               return 0;
+       if (ATTR_FALSE(check->value))
+               return 1;
+       return 0;
+}
+
+static int add_object_entry(const unsigned char *sha1, enum object_type type,
+                           const char *name, int exclude)
 {
-       uint32_t idx = nr_objects;
        struct object_entry *entry;
-       struct packed_git *p;
+       struct packed_git *p, *found_pack = NULL;
        off_t found_offset = 0;
-       struct packed_git *found_pack = NULL;
-       int ix, status = 0;
-
-       if (!exclude) {
-               for (p = packed_git; p; p = p->next) {
-                       off_t 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 = offset;
-                                       found_pack = p;
-                               }
+       int ix;
+       unsigned hash = name_hash(name);
+
+       ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
+       if (ix >= 0) {
+               if (exclude) {
+                       entry = objects + object_ix[ix] - 1;
+                       if (!entry->preferred_base)
+                               nr_result--;
+                       entry->preferred_base = 1;
+               }
+               return 0;
+       }
+
+       for (p = packed_git; p; p = p->next) {
+               off_t offset = find_pack_entry_one(sha1, p);
+               if (offset) {
+                       if (!found_pack) {
+                               found_offset = offset;
+                               found_pack = p;
                        }
+                       if (exclude)
+                               break;
+                       if (incremental)
+                               return 0;
+                       if (local && !p->pack_local)
+                               return 0;
                }
        }
-       if ((entry = locate_object_entry(sha1)) != NULL)
-               goto already_added;
 
-       if (idx >= nr_alloc) {
-               nr_alloc = (idx + 1024) * 3 / 2;
+       if (nr_objects >= nr_alloc) {
+               nr_alloc = (nr_alloc  + 1024) * 3 / 2;
                objects = xrealloc(objects, nr_alloc * sizeof(*entry));
        }
-       entry = objects + idx;
-       nr_objects = idx + 1;
+
+       entry = objects + nr_objects++;
        memset(entry, 0, sizeof(*entry));
-       hashcpy(entry->sha1, sha1);
+       hashcpy(entry->idx.sha1, sha1);
        entry->hash = hash;
+       if (type)
+               entry->type = type;
+       if (exclude)
+               entry->preferred_base = 1;
+       else
+               nr_result++;
+       if (found_pack) {
+               entry->in_pack = found_pack;
+               entry->in_pack_offset = found_offset;
+       }
 
        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;
+       else
+               object_ix[-1 - ix] = nr_objects;
 
- already_added:
-       if (progress_update) {
-               fprintf(stderr, "Counting objects...%u\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;
+       if (progress)
+               display_progress(&progress_state, nr_objects);
+
+       if (name && no_try_delta(name))
+               entry->no_try_delta = 1;
+
+       return 1;
 }
 
 struct pbase_tree_cache {
@@ -849,22 +978,22 @@ static void add_pbase_object(struct tree_desc *tree,
                             const char *fullname)
 {
        struct name_entry entry;
+       int cmp;
 
        while (tree_entry(tree,&entry)) {
-               unsigned long size;
-               enum object_type type;
-
-               if (tree_entry_len(entry.path, entry.sha1) != cmplen ||
-                   memcmp(entry.path, name, cmplen) ||
-                   !has_sha1_file(entry.sha1) ||
-                   (type = sha1_object_info(entry.sha1, &size)) < 0)
+               cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
+                     memcmp(name, entry.path, cmplen);
+               if (cmp > 0)
                        continue;
+               if (cmp < 0)
+                       return;
                if (name[cmplen] != '/') {
-                       unsigned hash = name_hash(fullname);
-                       add_object_entry(entry.sha1, hash, 1);
+                       add_object_entry(entry.sha1,
+                                        S_ISDIR(entry.mode) ? OBJ_TREE : OBJ_BLOB,
+                                        fullname, 1);
                        return;
                }
-               if (type == OBJ_TREE) {
+               if (S_ISDIR(entry.mode)) {
                        struct tree_desc sub;
                        struct pbase_tree_cache *tree;
                        const char *down = name+cmplen+1;
@@ -921,18 +1050,19 @@ static int check_pbase_path(unsigned hash)
        return 0;
 }
 
-static void add_preferred_base_object(const char *name, unsigned hash)
+static void add_preferred_base_object(const char *name)
 {
        struct pbase_tree *it;
-       int cmplen = name_cmp_len(name);
+       int cmplen;
+       unsigned hash = name_hash(name);
 
-       if (check_pbase_path(hash))
+       if (!num_preferred_base || check_pbase_path(hash))
                return;
 
+       cmplen = name_cmp_len(name);
        for (it = pbase_tree; it; it = it->next) {
                if (cmplen == 0) {
-                       hash = name_hash("");
-                       add_object_entry(it->pcache.sha1, hash, 1);
+                       add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
                }
                else {
                        struct tree_desc tree;
@@ -974,183 +1104,151 @@ static void add_preferred_base(unsigned char *sha1)
 
 static void check_object(struct object_entry *entry)
 {
-       if (entry->in_pack && !entry->preferred_base) {
+       if (entry->in_pack) {
                struct packed_git *p = entry->in_pack;
                struct pack_window *w_curs = NULL;
-               unsigned long size, used;
+               const unsigned char *base_ref = NULL;
+               struct object_entry *base_entry;
+               unsigned long used, used_0;
                unsigned int avail;
-               unsigned char *buf;
-               struct object_entry *base_entry = NULL;
+               off_t ofs;
+               unsigned char *buf, c;
 
                buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
 
-               /* We want in_pack_type even if we do not reuse delta.
-                * There is no point not reusing non-delta representations.
+               /*
+                * We want in_pack_type even if we do not reuse delta
+                * since non-delta representations could still be reused.
                 */
                used = unpack_object_header_gently(buf, avail,
-                                                  &entry->in_pack_type, &size);
+                                                  &entry->in_pack_type,
+                                                  &entry->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.
+               /*
+                * Determine if this is a delta and if so whether we can
+                * reuse it or not.  Otherwise let's find out as cheaply as
+                * possible what the actual type and size for this object is.
                 */
-               if (!no_reuse_delta) {
-                       unsigned char c;
-                       const unsigned char *base_name;
-                       off_t 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;
+               switch (entry->in_pack_type) {
+               default:
+                       /* Not a delta hence we've already got all we need. */
+                       entry->type = entry->in_pack_type;
+                       entry->in_pack_header_size = used;
+                       unuse_pack(&w_curs);
+                       return;
+               case OBJ_REF_DELTA:
+                       if (!no_reuse_delta && !entry->preferred_base)
+                               base_ref = use_pack(p, &w_curs,
+                                               entry->in_pack_offset + used, NULL);
+                       entry->in_pack_header_size = 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 || MSB(ofs, 7))
+                                       die("delta base offset overflow in pack for %s",
+                                           sha1_to_hex(entry->idx.sha1));
                                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;
+                               ofs = (ofs << 7) + (c & 127);
                        }
-                       if (base_name)
-                               base_entry = locate_object_entry(base_name);
+                       if (ofs >= entry->in_pack_offset)
+                               die("delta base offset out of bound for %s",
+                                   sha1_to_hex(entry->idx.sha1));
+                       ofs = entry->in_pack_offset - ofs;
+                       if (!no_reuse_delta && !entry->preferred_base)
+                               base_ref = find_packed_object_name(p, ofs);
+                       entry->in_pack_header_size = used + used_0;
+                       break;
                }
-               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
-                        * base object to deltify other objects
-                        * against, in order to avoid circular deltas.
+               if (base_ref && (base_entry = locate_object_entry(base_ref))) {
+                       /*
+                        * If base_ref was set above that means we wish to
+                        * reuse delta data, and we even found that base
+                        * in the list of objects we want to pack. Goodie!
+                        *
+                        * 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 = size;
-                       entry->delta = base_entry;
                        entry->type = entry->in_pack_type;
-
+                       entry->delta = base_entry;
                        entry->delta_sibling = base_entry->delta_child;
                        base_entry->delta_child = entry;
+                       unuse_pack(&w_curs);
+                       return;
+               }
 
+               if (entry->type) {
+                       /*
+                        * This must be a delta and we already know what the
+                        * final object type is.  Let's extract the actual
+                        * object size from the delta header.
+                        */
+                       entry->size = get_size_from_delta(p, &w_curs,
+                                       entry->in_pack_offset + entry->in_pack_header_size);
+                       unuse_pack(&w_curs);
                        return;
                }
-               /* Otherwise we would do the usual */
+
+               /*
+                * No choice but to fall back to the recursive delta walk
+                * with sha1_object_info() to find about the object type
+                * at this point...
+                */
+               unuse_pack(&w_curs);
        }
 
-       entry->type = sha1_object_info(entry->sha1, &entry->size);
+       entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
        if (entry->type < 0)
                die("unable to get type of object %s",
-                   sha1_to_hex(entry->sha1));
-}
-
-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;
+                   sha1_to_hex(entry->idx.sha1));
 }
 
-static void get_object_details(void)
+static int pack_offset_sort(const void *_a, const void *_b)
 {
-       uint32_t 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);
-       }
-}
+       const struct object_entry *a = *(struct object_entry **)_a;
+       const struct object_entry *b = *(struct object_entry **)_b;
 
-typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
+       /* avoid filesystem trashing with loose objects */
+       if (!a->in_pack && !b->in_pack)
+               return hashcmp(a->idx.sha1, b->idx.sha1);
 
-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);
+       if (a->in_pack < b->in_pack)
+               return -1;
+       if (a->in_pack > b->in_pack)
+               return 1;
+       return a->in_pack_offset < b->in_pack_offset ? -1 :
+                       (a->in_pack_offset > b->in_pack_offset);
 }
 
-static struct object_entry **create_sorted_list(entry_sort_t sort)
+static void get_object_details(void)
 {
-       struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
        uint32_t i;
+       struct object_entry **sorted_by_offset;
 
+       sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
        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;
-}
+               sorted_by_offset[i] = objects + i;
+       qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
 
-static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
-{
-       return hashcmp(a->sha1, b->sha1);
+       prepare_pack_ix();
+       for (i = 0; i < nr_objects; i++)
+               check_object(sorted_by_offset[i]);
+       free(sorted_by_offset);
 }
 
-static struct object_entry **create_final_object_list(void)
+static int type_size_sort(const void *_a, const void *_b)
 {
-       struct object_entry **list;
-       uint32_t 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;
-}
+       const struct object_entry *a = *(struct object_entry **)_a;
+       const struct object_entry *b = *(struct object_entry **)_b;
 
-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)
@@ -1167,15 +1265,33 @@ static int type_size_sort(const struct object_entry *a, const struct object_entr
                return -1;
        if (a->size > b->size)
                return 1;
-       return a < b ? -1 : (a > b);
+       return a > b ? -1 : (a < b);  /* newest last */
 }
 
 struct unpacked {
        struct object_entry *entry;
        void *data;
        struct delta_index *index;
+       unsigned depth;
 };
 
+static int delta_cacheable(struct unpacked *trg, struct unpacked *src,
+                           unsigned long src_size, unsigned long trg_size,
+                           unsigned long delta_size)
+{
+       if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
+               return 0;
+
+       if (delta_size < cache_max_small_delta_size)
+               return 1;
+
+       /* cache delta, if objects are large enough compared to delta size */
+       if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
+               return 1;
+
+       return 0;
+}
+
 /*
  * We search for deltas _backwards_ in a list sorted by type and
  * by size, so that we see progressively smaller and smaller files.
@@ -1190,6 +1306,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
        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;
+       unsigned ref_depth;
        enum object_type type;
        void *delta_buf;
 
@@ -1213,80 +1330,123 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
            trg_entry->in_pack_type != OBJ_OFS_DELTA)
                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)
+       /* Let's not bust the allowed depth. */
+       if (src->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 (!trg_entry->delta) {
+               max_size = trg_size/2 - 20;
+               ref_depth = 1;
+       } else {
+               max_size = trg_entry->delta_size;
+               ref_depth = trg->depth;
+       }
+       max_size = max_size * (max_depth - src->depth) /
+                                               (max_depth - ref_depth + 1);
        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;
+       if (trg_size < src_size / 32)
+               return 0;
 
        /* Load data if not already done */
        if (!trg->data) {
-               trg->data = read_sha1_file(trg_entry->sha1, &type, &sz);
+               trg->data = read_sha1_file(trg_entry->idx.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);
+                           sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
+               window_memory_usage += sz;
        }
        if (!src->data) {
-               src->data = read_sha1_file(src_entry->sha1, &type, &sz);
+               src->data = read_sha1_file(src_entry->idx.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);
+                           sha1_to_hex(src_entry->idx.sha1), sz, src_size);
+               window_memory_usage += sz;
        }
        if (!src->index) {
                src->index = create_delta_index(src->data, src_size);
-               if (!src->index)
-                       die("out of memory");
+               if (!src->index) {
+                       static int warned = 0;
+                       if (!warned++)
+                               warning("suboptimal pack - out of memory");
+                       return 0;
+               }
+               window_memory_usage += sizeof_delta_index(src->index);
        }
 
        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
        if (!delta_buf)
                return 0;
 
+       if (trg_entry->delta_data) {
+               /* Prefer only shallower same-sized deltas. */
+               if (delta_size == trg_entry->delta_size &&
+                   src->depth + 1 >= trg->depth) {
+                       free(delta_buf);
+                       return 0;
+               }
+               delta_cache_size -= trg_entry->delta_size;
+               free(trg_entry->delta_data);
+               trg_entry->delta_data = NULL;
+       }
        trg_entry->delta = src_entry;
        trg_entry->delta_size = delta_size;
-       trg_entry->depth = src_entry->depth + 1;
-       free(delta_buf);
+       trg->depth = src->depth + 1;
+
+       if (delta_cacheable(src, trg, src_size, trg_size, delta_size)) {
+               trg_entry->delta_data = xrealloc(delta_buf, delta_size);
+               delta_cache_size += trg_entry->delta_size;
+       } else
+               free(delta_buf);
        return 1;
 }
 
-static void progress_interval(int signum)
+static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
 {
-       progress_update = 1;
+       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 free_unpacked(struct unpacked *n)
+{
+       window_memory_usage -= sizeof_delta_index(n->index);
+       free_delta_index(n->index);
+       n->index = NULL;
+       if (n->data) {
+               free(n->data);
+               n->data = NULL;
+               window_memory_usage -= n->entry->size;
+       }
+       n->entry = NULL;
+       n->depth = 0;
 }
 
 static void find_deltas(struct object_entry **list, int window, int depth)
 {
-       uint32_t i = nr_objects, idx = 0, processed = 0;
+       uint32_t i = nr_objects, idx = 0, count = 0, processed = 0;
        unsigned int array_size = window * sizeof(struct unpacked);
        struct unpacked *array;
-       unsigned last_percent = 999;
+       int max_depth;
 
        if (!nr_objects)
                return;
        array = xmalloc(array_size);
        memset(array, 0, array_size);
        if (progress)
-               fprintf(stderr, "Deltifying %u objects.\n", nr_result);
+               start_progress(&progress_state, "Deltifying %u objects...", "", nr_result);
 
        do {
                struct object_entry *entry = list[--i];
@@ -1296,15 +1456,8 @@ static void find_deltas(struct object_entry **list, int window, int depth)
                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 (progress)
+                       display_progress(&progress_state, processed);
 
                if (entry->delta)
                        /* This happens if we decided to reuse existing
@@ -1314,12 +1467,33 @@ static void find_deltas(struct object_entry **list, int window, int depth)
 
                if (entry->size < 50)
                        continue;
-               free_delta_index(n->index);
-               n->index = NULL;
-               free(n->data);
-               n->data = NULL;
+
+               if (entry->no_try_delta)
+                       continue;
+
+               free_unpacked(n);
                n->entry = entry;
 
+               while (window_memory_limit &&
+                      window_memory_usage > window_memory_limit &&
+                      count > 1) {
+                       uint32_t tail = (idx + window - count) % window;
+                       free_unpacked(array + tail);
+                       count--;
+               }
+
+               /*
+                * 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.
+                */
+               max_depth = depth;
+               if (entry->delta_child) {
+                       max_depth -= check_delta_limit(entry, 0);
+                       if (max_depth <= 0)
+                               goto next;
+               }
+
                j = window;
                while (--j > 0) {
                        uint32_t other_idx = idx + j;
@@ -1329,23 +1503,27 @@ static void find_deltas(struct object_entry **list, int window, int depth)
                        m = array + other_idx;
                        if (!m->entry)
                                break;
-                       if (try_delta(n, m, depth) < 0)
+                       if (try_delta(n, m, max_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)
+               if (entry->delta && depth <= n->depth)
                        continue;
 
+               next:
                idx++;
+               if (count + 1 < window)
+                       count++;
                if (idx >= window)
                        idx = 0;
        } while (i > 0);
 
        if (progress)
-               fputc('\n', stderr);
+               stop_progress(&progress_state);
 
        for (i = 0; i < window; ++i) {
                free_delta_index(array[i].index);
@@ -1356,81 +1534,20 @@ static void find_deltas(struct object_entry **list, int window, int depth)
 
 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)
-{
-       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 %u objects pack %s\n", nr_objects,
-                       sha1_to_hex(sha1));
+       struct object_entry **delta_list;
+       uint32_t 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);
-
-               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));
-       }
+       get_object_details();
 
-       return 1;
-}
+       if (!window || !depth)
+               return;
 
-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);
+       delta_list = xmalloc(nr_objects * sizeof(*delta_list));
+       for (i = 0; i < nr_objects; i++)
+               delta_list[i] = objects + i;
+       qsort(delta_list, nr_objects, sizeof(*delta_list), type_size_sort);
+       find_deltas(delta_list, window+1, depth);
+       free(delta_list);
 }
 
 static int git_pack_config(const char *k, const char *v)
@@ -1439,6 +1556,32 @@ static int git_pack_config(const char *k, const char *v)
                window = git_config_int(k, v);
                return 0;
        }
+       if (!strcmp(k, "pack.windowmemory")) {
+               window_memory_limit = git_config_ulong(k, v);
+               return 0;
+       }
+       if (!strcmp(k, "pack.depth")) {
+               depth = git_config_int(k, v);
+               return 0;
+       }
+       if (!strcmp(k, "pack.compression")) {
+               int level = git_config_int(k, v);
+               if (level == -1)
+                       level = Z_DEFAULT_COMPRESSION;
+               else if (level < 0 || level > Z_BEST_COMPRESSION)
+                       die("bad pack compression level %d", level);
+               pack_compression_level = level;
+               pack_compression_seen = 1;
+               return 0;
+       }
+       if (!strcmp(k, "pack.deltacachesize")) {
+               max_delta_cache_size = git_config_int(k, v);
+               return 0;
+       }
+       if (!strcmp(k, "pack.deltacachelimit")) {
+               cache_max_small_delta_size = git_config_int(k, v);
+               return 0;
+       }
        return git_default_config(k, v);
 }
 
@@ -1446,7 +1589,6 @@ 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)) {
@@ -1469,24 +1611,20 @@ static void read_object_list_from_stdin(void)
                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);
+               add_preferred_base_object(line+41);
+               add_object_entry(sha1, 0, line+41, 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);
+       add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 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);
+       add_preferred_base_object(p->name);
+       add_object_entry(p->item->sha1, p->item->type, p->name, 0);
 }
 
 static void show_edge(struct commit *commit)
@@ -1527,11 +1665,15 @@ static void get_object_list(int ac, const char **av)
        traverse_commit_list(&revs, show_commit, show_object);
 }
 
+static int adjust_perm(const char *path, mode_t mode)
+{
+       if (chmod(path, mode))
+               return -1;
+       return adjust_shared_perm(path);
+}
+
 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 {
-       SHA_CTX ctx;
-       int depth = 10;
-       struct object_entry **list;
        int use_internal_rev_list = 0;
        int thin = 0;
        uint32_t i;
@@ -1546,6 +1688,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
        rp_ac = 2;
 
        git_config(git_pack_config);
+       if (!pack_compression_seen && core_compression_seen)
+               pack_compression_level = core_compression_level;
 
        progress = isatty(2);
        for (i = 1; i < argc; i++) {
@@ -1566,6 +1710,25 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                        incremental = 1;
                        continue;
                }
+               if (!prefixcmp(arg, "--compression=")) {
+                       char *end;
+                       int level = strtoul(arg+14, &end, 0);
+                       if (!arg[14] || *end)
+                               usage(pack_usage);
+                       if (level == -1)
+                               level = Z_DEFAULT_COMPRESSION;
+                       else if (level < 0 || level > Z_BEST_COMPRESSION)
+                               die("bad pack compression level %d", level);
+                       pack_compression_level = level;
+                       continue;
+               }
+               if (!prefixcmp(arg, "--max-pack-size=")) {
+                       char *end;
+                       pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
+                       if (!arg[16] || *end)
+                               usage(pack_usage);
+                       continue;
+               }
                if (!prefixcmp(arg, "--window=")) {
                        char *end;
                        window = strtoul(arg+9, &end, 0);
@@ -1573,6 +1736,11 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                                usage(pack_usage);
                        continue;
                }
+               if (!prefixcmp(arg, "--window-memory=")) {
+                       if (!git_parse_ulong(arg+16, &window_memory_limit))
+                               usage(pack_usage);
+                       continue;
+               }
                if (!prefixcmp(arg, "--depth=")) {
                        char *end;
                        depth = strtoul(arg+8, &end, 0);
@@ -1596,6 +1764,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                        no_reuse_delta = 1;
                        continue;
                }
+               if (!strcmp("--no-reuse-object", arg)) {
+                       no_reuse_object = no_reuse_delta = 1;
+                       continue;
+               }
                if (!strcmp("--delta-base-offset", arg)) {
                        allow_ofs_delta = 1;
                        continue;
@@ -1627,6 +1799,17 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                        rp_av[1] = "--objects-edge";
                        continue;
                }
+               if (!prefixcmp(arg, "--index-version=")) {
+                       char *c;
+                       pack_idx_default_version = strtoul(arg + 16, &c, 10);
+                       if (pack_idx_default_version > 2)
+                               die("bad %s", arg);
+                       if (*c == ',')
+                               pack_idx_off32_limit = strtoul(c+1, &c, 0);
+                       if (*c || pack_idx_off32_limit & 0x80000000)
+                               die("bad %s", arg);
+                       continue;
+               }
                usage(pack_usage);
        }
 
@@ -1649,57 +1832,35 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
        if (pack_to_stdout != !base_name)
                usage(pack_usage);
 
+       if (pack_to_stdout && pack_size_limit)
+               die("--max-pack-size cannot be used to build a pack for transfer.");
+
        if (!pack_to_stdout && thin)
                die("--thin cannot be used to build an indexable pack.");
 
        prepare_packed_git();
 
-       if (progress) {
-               fprintf(stderr, "Generating pack...\n");
-               setup_progress_signal();
-       }
-
+       if (progress)
+               start_progress(&progress_state, "Generating pack...",
+                              "Counting objects: ", 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)
+       if (progress) {
+               stop_progress(&progress_state);
                fprintf(stderr, "Done counting %u 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 %u objects.\n", nr_result);
-
-       if (reuse_cached_pack(object_list_sha1))
-               ;
-       else {
-               if (nr_result)
-                       prepare_pack(window, depth);
-               if (progress == 1 && 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 (nr_result)
+               prepare_pack(window, depth);
+       write_pack_file();
        if (progress)
                fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
                        written, written_delta, reused, reused_delta);