X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=fast-import.c;h=2c500d6be32e8b83e8c7bd0c3768f3b9e6a08907;hb=6f64f6d9d2b12cdae1648cbf536685c888f3b981;hp=309f4d353bb32e33f5e98980afcda48ebd6c41a1;hpb=35ef237cf630418c2e45752eb527268693a2895b;p=thirdparty%2Fgit.git

diff --git a/fast-import.c b/fast-import.c
index 309f4d353b..2c500d6be3 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -6,6 +6,7 @@ Format of STDIN stream:
   cmd ::= new_blob
         | new_commit
         | new_tag
+        | reset_branch
         ;
 
   new_blob ::= 'blob' lf
@@ -19,6 +20,7 @@ Format of STDIN stream:
     'committer' sp name '<' email '>' ts tz lf
     commit_msg
     ('from' sp (ref_str | hexsha1 | sha1exp_str | idnum) lf)?
+    ('merge' sp (ref_str | hexsha1 | sha1exp_str | idnum) lf)*
     file_change*
     lf;
   commit_msg ::= data;
@@ -34,6 +36,13 @@ Format of STDIN stream:
     tag_msg;
   tag_msg ::= data;
 
+  reset_branch ::= 'reset' sp ref_str lf
+    ('from' sp (ref_str | hexsha1 | sha1exp_str | idnum) lf)?
+    lf;
+
+  checkpoint ::= 'checkpoint' lf
+    lf;
+
      # note: the first idnum in a stream should be 1 and subsequent
      # idnums should not have gaps between values as this will cause
      # the stream parser to reserve space for the gapped values.  An
@@ -63,6 +72,7 @@ Format of STDIN stream:
   path_str    ::= path    | '"' quoted(path)    '"' ;
 
   declen ::= # unsigned 32 bit value, ascii base10 notation;
+  bigint ::= # unsigned integer value, ascii base10 notation;
   binary_data ::= # file content, not interpreted;
 
   sp ::= # ASCII space character;
@@ -72,7 +82,7 @@ Format of STDIN stream:
 	 # an idnum.  This is to distinguish it from a ref or tag name as
      # GIT does not permit ':' in ref or tag strings.
 	 #
-  idnum   ::= ':' declen;
+  idnum   ::= ':' bigint;
   path    ::= # GIT style file path, e.g. "a/b/c";
   ref     ::= # GIT ref name, e.g. "refs/heads/MOZ_GECKO_EXPERIMENT";
   tag     ::= # GIT tag name, e.g. "FIREFOX_1_5";
@@ -104,8 +114,9 @@ Format of STDIN stream:
 struct object_entry
 {
 	struct object_entry *next;
-	enum object_type type;
 	unsigned long offset;
+	unsigned type : TYPE_BITS;
+	unsigned pack_id : 16;
 	unsigned char sha1[20];
 };
 
@@ -119,19 +130,20 @@ struct object_entry_pool
 
 struct mark_set
 {
-	int shift;
 	union {
 		struct object_entry *marked[1024];
 		struct mark_set *sets[1024];
 	} data;
+	unsigned int shift;
 };
 
 struct last_object
 {
 	void *data;
-	unsigned int len;
+	unsigned long len;
+	unsigned long offset;
 	unsigned int depth;
-	unsigned char sha1[20];
+	unsigned no_free:1;
 };
 
 struct mem_pool
@@ -145,7 +157,7 @@ struct mem_pool
 struct atom_str
 {
 	struct atom_str *next_atom;
-	int str_len;
+	unsigned int str_len;
 	char str_dat[FLEX_ARRAY]; /* more */
 };
 
@@ -154,14 +166,18 @@ struct tree_entry
 {
 	struct tree_content *tree;
 	struct atom_str* name;
-	unsigned int mode;
-	unsigned char sha1[20];
+	struct tree_entry_ms
+	{
+		unsigned int mode;
+		unsigned char sha1[20];
+	} versions[2];
 };
 
 struct tree_content
 {
 	unsigned int entry_capacity; /* must match avail_tree_content */
 	unsigned int entry_count;
+	unsigned int delta_depth;
 	struct tree_entry *entries[FLEX_ARRAY]; /* more */
 };
 
@@ -176,8 +192,9 @@ struct branch
 	struct branch *table_next_branch;
 	struct branch *active_next_branch;
 	const char *name;
-	unsigned long last_commit;
 	struct tree_entry branch_tree;
+	unsigned long last_commit;
+	unsigned int pack_id;
 	unsigned char sha1[20];
 };
 
@@ -185,21 +202,36 @@ struct tag
 {
 	struct tag *next_tag;
 	const char *name;
+	unsigned int pack_id;
 	unsigned char sha1[20];
 };
 
+struct dbuf
+{
+	void *buffer;
+	size_t capacity;
+};
 
-/* Stats and misc. counters */
+struct hash_list
+{
+	struct hash_list *next;
+	unsigned char sha1[20];
+};
+
+/* Configured limits on output */
 static unsigned long max_depth = 10;
-static unsigned long alloc_count;
+static unsigned long max_packsize = (1LL << 32) - 1;
+static uintmax_t max_objects = -1;
+
+/* Stats and misc. counters */
+static uintmax_t alloc_count;
+static uintmax_t marks_set_count;
+static uintmax_t object_count_by_type[1 << TYPE_BITS];
+static uintmax_t duplicate_count_by_type[1 << TYPE_BITS];
+static uintmax_t delta_count_by_type[1 << TYPE_BITS];
+static unsigned long object_count;
 static unsigned long branch_count;
 static unsigned long branch_load_count;
-static unsigned long remap_count;
-static unsigned long object_count;
-static unsigned long duplicate_count;
-static unsigned long marks_set_count;
-static unsigned long object_count_by_type[9];
-static unsigned long duplicate_count_by_type[9];
 
 /* Memory pools */
 static size_t mem_pool_alloc = 2*1024*1024 - sizeof(struct mem_pool);
@@ -212,14 +244,13 @@ static unsigned int atom_cnt;
 static struct atom_str **atom_table;
 
 /* The .pack file being generated */
-static int pack_fd;
+static unsigned int pack_id;
+static struct packed_git *pack_data;
+static struct packed_git **all_packs;
 static unsigned long pack_size;
-static unsigned char pack_sha1[20];
-static void* pack_base;
-static size_t pack_mlen;
 
 /* Table of objects we've written. */
-static unsigned int object_entry_alloc = 1000;
+static unsigned int object_entry_alloc = 5000;
 static struct object_entry_pool *blocks;
 static struct object_entry *object_table[1 << 16];
 static struct mark_set *marks;
@@ -233,6 +264,8 @@ static unsigned int tree_entry_alloc = 1000;
 static void *avail_tree_entry;
 static unsigned int avail_tree_table_sz = 100;
 static struct avail_tree_content **avail_tree_table;
+static struct dbuf old_tree;
+static struct dbuf new_tree;
 
 /* Branch data */
 static unsigned long max_active_branches = 5;
@@ -247,11 +280,12 @@ static struct tag *last_tag;
 
 /* Input stream parsing */
 static struct strbuf command_buf;
-static unsigned long next_mark;
+static uintmax_t next_mark;
+static struct dbuf new_data;
 static FILE* branch_log;
 
 
-static void alloc_objects(int cnt)
+static void alloc_objects(unsigned int cnt)
 {
 	struct object_entry_pool *b;
 
@@ -272,7 +306,7 @@ static struct object_entry* new_object(unsigned char *sha1)
 		alloc_objects(object_entry_alloc);
 
 	e = blocks->next_free++;
-	memcpy(e->sha1, sha1, sizeof(e->sha1));
+	hashcpy(e->sha1, sha1);
 	return e;
 }
 
@@ -281,7 +315,7 @@ static struct object_entry* find_object(unsigned char *sha1)
 	unsigned int h = sha1[0] << 8 | sha1[1];
 	struct object_entry *e;
 	for (e = object_table[h]; e; e = e->next)
-		if (!memcmp(sha1, e->sha1, sizeof(e->sha1)))
+		if (!hashcmp(sha1, e->sha1))
 			return e;
 	return NULL;
 }
@@ -293,7 +327,7 @@ static struct object_entry* insert_object(unsigned char *sha1)
 	struct object_entry *p = NULL;
 
 	while (e) {
-		if (!memcmp(sha1, e->sha1, sizeof(e->sha1)))
+		if (!hashcmp(sha1, e->sha1))
 			return e;
 		p = e;
 		e = e->next;
@@ -362,7 +396,18 @@ static char* pool_strdup(const char *s)
 	return r;
 }
 
-static void insert_mark(unsigned long idnum, struct object_entry *oe)
+static void size_dbuf(struct dbuf *b, size_t maxlen)
+{
+	if (b->buffer) {
+		if (b->capacity >= maxlen)
+			return;
+		free(b->buffer);
+	}
+	b->capacity = ((maxlen / 1024) + 1) * 1024;
+	b->buffer = xmalloc(b->capacity);
+}
+
+static void insert_mark(uintmax_t idnum, struct object_entry *oe)
 {
 	struct mark_set *s = marks;
 	while ((idnum >> s->shift) >= 1024) {
@@ -372,7 +417,7 @@ static void insert_mark(unsigned long idnum, struct object_entry *oe)
 		marks = s;
 	}
 	while (s->shift) {
-		unsigned long i = idnum >> s->shift;
+		uintmax_t i = idnum >> s->shift;
 		idnum -= i << s->shift;
 		if (!s->data.sets[i]) {
 			s->data.sets[i] = pool_calloc(1, sizeof(struct mark_set));
@@ -385,14 +430,14 @@ static void insert_mark(unsigned long idnum, struct object_entry *oe)
 	s->data.marked[idnum] = oe;
 }
 
-static struct object_entry* find_mark(unsigned long idnum)
+static struct object_entry* find_mark(uintmax_t idnum)
 {
-	unsigned long orig_idnum = idnum;
+	uintmax_t orig_idnum = idnum;
 	struct mark_set *s = marks;
 	struct object_entry *oe = NULL;
 	if ((idnum >> s->shift) < 1024) {
 		while (s && s->shift) {
-			unsigned long i = idnum >> s->shift;
+			uintmax_t i = idnum >> s->shift;
 			idnum -= i << s->shift;
 			s = s->data.sets[i];
 		}
@@ -400,7 +445,7 @@ static struct object_entry* find_mark(unsigned long idnum)
 			oe = s->data.marked[idnum];
 	}
 	if (!oe)
-		die("mark :%lu not declared", orig_idnum);
+		die("mark :%ju not declared", orig_idnum);
 	return oe;
 }
 
@@ -447,6 +492,8 @@ static struct branch* new_branch(const char *name)
 	b = pool_calloc(1, sizeof(struct branch));
 	b->name = pool_strdup(name);
 	b->table_next_branch = branch_table[hc];
+	b->branch_tree.versions[0].mode = S_IFDIR;
+	b->branch_tree.versions[1].mode = S_IFDIR;
 	branch_table[hc] = b;
 	branch_count++;
 	return b;
@@ -481,6 +528,7 @@ static struct tree_content* new_tree_content(unsigned int cnt)
 
 	t = (struct tree_content*)f;
 	t->entry_count = 0;
+	t->delta_depth = 0;
 	return t;
 }
 
@@ -507,6 +555,7 @@ static struct tree_content* grow_tree_content(
 {
 	struct tree_content *r = new_tree_content(t->entry_count + amt);
 	r->entry_count = t->entry_count;
+	r->delta_depth = t->delta_depth;
 	memcpy(r->entries,t->entries,t->entry_count*sizeof(t->entries[0]));
 	release_tree_content(t);
 	return r;
@@ -540,30 +589,227 @@ static void release_tree_entry(struct tree_entry *e)
 	avail_tree_entry = e;
 }
 
-static void yread(int fd, void *buffer, size_t length)
+static void start_packfile()
+{
+	static char tmpfile[PATH_MAX];
+	struct packed_git *p;
+	struct pack_header hdr;
+	int pack_fd;
+
+	snprintf(tmpfile, sizeof(tmpfile),
+		"%s/pack_XXXXXX", get_object_directory());
+	pack_fd = mkstemp(tmpfile);
+	if (pack_fd < 0)
+		die("Can't create %s: %s", tmpfile, strerror(errno));
+	p = xcalloc(1, sizeof(*p) + strlen(tmpfile) + 2);
+	strcpy(p->pack_name, tmpfile);
+	p->pack_fd = pack_fd;
+
+	hdr.hdr_signature = htonl(PACK_SIGNATURE);
+	hdr.hdr_version = htonl(2);
+	hdr.hdr_entries = 0;
+	write_or_die(p->pack_fd, &hdr, sizeof(hdr));
+
+	pack_data = p;
+	pack_size = sizeof(hdr);
+	object_count = 0;
+
+	all_packs = xrealloc(all_packs, sizeof(*all_packs) * (pack_id + 1));
+	all_packs[pack_id] = p;
+}
+
+static void fixup_header_footer()
 {
-	ssize_t ret = 0;
-	while (ret < length) {
-		ssize_t size = xread(fd, (char *) buffer + ret, length - ret);
-		if (!size)
-			die("Read from descriptor %i: end of stream", fd);
-		if (size < 0)
-			die("Read from descriptor %i: %s", fd, strerror(errno));
-		ret += size;
+	int pack_fd = pack_data->pack_fd;
+	SHA_CTX c;
+	char hdr[8];
+	unsigned long cnt;
+	char *buf;
+
+	if (lseek(pack_fd, 0, SEEK_SET) != 0)
+		die("Failed seeking to start: %s", strerror(errno));
+
+	SHA1_Init(&c);
+	if (read_in_full(pack_fd, hdr, 8) != 8)
+		die("Unable to reread header of %s", pack_data->pack_name);
+	SHA1_Update(&c, hdr, 8);
+
+	cnt = htonl(object_count);
+	SHA1_Update(&c, &cnt, 4);
+	write_or_die(pack_fd, &cnt, 4);
+
+	buf = xmalloc(128 * 1024);
+	for (;;) {
+		size_t n = xread(pack_fd, buf, 128 * 1024);
+		if (n <= 0)
+			break;
+		SHA1_Update(&c, buf, n);
 	}
+	free(buf);
+
+	SHA1_Final(pack_data->sha1, &c);
+	write_or_die(pack_fd, pack_data->sha1, sizeof(pack_data->sha1));
+	close(pack_fd);
+}
+
+static int oecmp (const void *a_, const void *b_)
+{
+	struct object_entry *a = *((struct object_entry**)a_);
+	struct object_entry *b = *((struct object_entry**)b_);
+	return hashcmp(a->sha1, b->sha1);
 }
 
-static void ywrite(int fd, void *buffer, size_t length)
+static char* create_index()
 {
-	ssize_t ret = 0;
-	while (ret < length) {
-		ssize_t size = xwrite(fd, (char *) buffer + ret, length - ret);
-		if (!size)
-			die("Write to descriptor %i: end of file", fd);
-		if (size < 0)
-			die("Write to descriptor %i: %s", fd, strerror(errno));
-		ret += size;
+	static char tmpfile[PATH_MAX];
+	SHA_CTX ctx;
+	struct sha1file *f;
+	struct object_entry **idx, **c, **last, *e;
+	struct object_entry_pool *o;
+	unsigned int array[256];
+	int i, idx_fd;
+
+	/* Build the sorted table of object IDs. */
+	idx = xmalloc(object_count * sizeof(struct object_entry*));
+	c = idx;
+	for (o = blocks; o; o = o->next_pool)
+		for (e = o->next_free; e-- != o->entries;)
+			if (pack_id == e->pack_id)
+				*c++ = e;
+	last = idx + object_count;
+	if (c != last)
+		die("internal consistency error creating the index");
+	qsort(idx, object_count, sizeof(struct object_entry*), oecmp);
+
+	/* Generate the fan-out array. */
+	c = idx;
+	for (i = 0; i < 256; i++) {
+		struct object_entry **next = c;;
+		while (next < last) {
+			if ((*next)->sha1[0] != i)
+				break;
+			next++;
+		}
+		array[i] = htonl(next - idx);
+		c = next;
+	}
+
+	snprintf(tmpfile, sizeof(tmpfile),
+		"%s/index_XXXXXX", get_object_directory());
+	idx_fd = mkstemp(tmpfile);
+	if (idx_fd < 0)
+		die("Can't create %s: %s", tmpfile, strerror(errno));
+	f = sha1fd(idx_fd, tmpfile);
+	sha1write(f, array, 256 * sizeof(int));
+	SHA1_Init(&ctx);
+	for (c = idx; c != last; c++) {
+		unsigned int offset = htonl((*c)->offset);
+		sha1write(f, &offset, 4);
+		sha1write(f, (*c)->sha1, sizeof((*c)->sha1));
+		SHA1_Update(&ctx, (*c)->sha1, 20);
+	}
+	sha1write(f, pack_data->sha1, sizeof(pack_data->sha1));
+	sha1close(f, NULL, 1);
+	free(idx);
+	SHA1_Final(pack_data->sha1, &ctx);
+	return tmpfile;
+}
+
+static char* keep_pack(char *curr_index_name)
+{
+	static char name[PATH_MAX];
+	static char *keep_msg = "fast-import";
+	int keep_fd;
+
+	chmod(pack_data->pack_name, 0444);
+	chmod(curr_index_name, 0444);
+
+	snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
+		 get_object_directory(), sha1_to_hex(pack_data->sha1));
+	keep_fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
+	if (keep_fd < 0)
+		die("cannot create keep file");
+	write(keep_fd, keep_msg, strlen(keep_msg));
+	close(keep_fd);
+
+	snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
+		 get_object_directory(), sha1_to_hex(pack_data->sha1));
+	if (move_temp_to_file(pack_data->pack_name, name))
+		die("cannot store pack file");
+
+	snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
+		 get_object_directory(), sha1_to_hex(pack_data->sha1));
+	if (move_temp_to_file(curr_index_name, name))
+		die("cannot store index file");
+	return name;
+}
+
+static void unkeep_all_packs()
+{
+	static char name[PATH_MAX];
+	int k;
+
+	for (k = 0; k < pack_id; k++) {
+		struct packed_git *p = all_packs[k];
+		snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
+			 get_object_directory(), sha1_to_hex(p->sha1));
+		unlink(name);
+	}
+}
+
+static void end_packfile()
+{
+	struct packed_git *old_p = pack_data, *new_p;
+
+	if (object_count) {
+		char *idx_name;
+		int i;
+		struct branch *b;
+		struct tag *t;
+
+		fixup_header_footer();
+		idx_name = keep_pack(create_index());
+
+		/* Register the packfile with core git's machinary. */
+		new_p = add_packed_git(idx_name, strlen(idx_name), 1);
+		if (!new_p)
+			die("core git rejected index %s", idx_name);
+		new_p->windows = old_p->windows;
+		all_packs[pack_id] = new_p;
+		install_packed_git(new_p);
+
+		/* Print the boundary */
+		fprintf(stdout, "%s:", new_p->pack_name);
+		for (i = 0; i < branch_table_sz; i++) {
+			for (b = branch_table[i]; b; b = b->table_next_branch) {
+				if (b->pack_id == pack_id)
+					fprintf(stdout, " %s", sha1_to_hex(b->sha1));
+			}
+		}
+		for (t = first_tag; t; t = t->next_tag) {
+			if (t->pack_id == pack_id)
+				fprintf(stdout, " %s", sha1_to_hex(t->sha1));
+		}
+		fputc('\n', stdout);
+
+		pack_id++;
 	}
+	else
+		unlink(old_p->pack_name);
+	free(old_p);
+
+	/* We can't carry a delta across packfiles. */
+	free(last_blob.data);
+	last_blob.data = NULL;
+	last_blob.len = 0;
+	last_blob.offset = 0;
+	last_blob.depth = 0;
+}
+
+static void checkpoint()
+{
+	end_packfile();
+	start_packfile();
 }
 
 static size_t encode_header(
@@ -574,7 +820,7 @@ static size_t encode_header(
 	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);
@@ -595,7 +841,7 @@ static int store_object(
 	size_t datlen,
 	struct last_object *last,
 	unsigned char *sha1out,
-	unsigned long mark)
+	uintmax_t mark)
 {
 	void *out, *delta;
 	struct object_entry *e;
@@ -611,190 +857,124 @@ static int store_object(
 	SHA1_Update(&c, dat, datlen);
 	SHA1_Final(sha1, &c);
 	if (sha1out)
-		memcpy(sha1out, sha1, sizeof(sha1));
+		hashcpy(sha1out, sha1);
 
 	e = insert_object(sha1);
 	if (mark)
 		insert_mark(mark, e);
 	if (e->offset) {
-		duplicate_count++;
 		duplicate_count_by_type[type]++;
 		return 1;
 	}
-	e->type = type;
-	e->offset = pack_size;
-	object_count++;
-	object_count_by_type[type]++;
 
-	if (last && last->data && last->depth < max_depth)
+	if (last && last->data && last->depth < max_depth) {
 		delta = diff_delta(last->data, last->len,
 			dat, datlen,
 			&deltalen, 0);
-	else
-		delta = 0;
+		if (delta && deltalen >= datlen) {
+			free(delta);
+			delta = NULL;
+		}
+	} else
+		delta = NULL;
 
 	memset(&s, 0, sizeof(s));
 	deflateInit(&s, zlib_compression_level);
-
 	if (delta) {
-		last->depth++;
 		s.next_in = delta;
 		s.avail_in = deltalen;
-		hdrlen = encode_header(OBJ_DELTA, deltalen, hdr);
-		ywrite(pack_fd, hdr, hdrlen);
-		ywrite(pack_fd, last->sha1, sizeof(sha1));
-		pack_size += hdrlen + sizeof(sha1);
 	} else {
-		if (last)
-			last->depth = 0;
 		s.next_in = dat;
 		s.avail_in = datlen;
-		hdrlen = encode_header(type, datlen, hdr);
-		ywrite(pack_fd, hdr, hdrlen);
-		pack_size += hdrlen;
 	}
-
 	s.avail_out = deflateBound(&s, s.avail_in);
 	s.next_out = out = xmalloc(s.avail_out);
 	while (deflate(&s, Z_FINISH) == Z_OK)
 		/* nothing */;
 	deflateEnd(&s);
 
-	ywrite(pack_fd, out, s.total_out);
+	/* Determine if we should auto-checkpoint. */
+	if ((object_count + 1) > max_objects
+		|| (object_count + 1) < object_count
+		|| (pack_size + 60 + s.total_out) > max_packsize
+		|| (pack_size + 60 + s.total_out) < pack_size) {
+
+		/* This new object needs to *not* have the current pack_id. */
+		e->pack_id = pack_id + 1;
+		checkpoint();
+
+		/* We cannot carry a delta into the new pack. */
+		if (delta) {
+			free(delta);
+			delta = NULL;
+
+			memset(&s, 0, sizeof(s));
+			deflateInit(&s, zlib_compression_level);
+			s.next_in = dat;
+			s.avail_in = datlen;
+			s.avail_out = deflateBound(&s, s.avail_in);
+			s.next_out = out = xrealloc(out, s.avail_out);
+			while (deflate(&s, Z_FINISH) == Z_OK)
+				/* nothing */;
+			deflateEnd(&s);
+		}
+	}
+
+	e->type = type;
+	e->pack_id = pack_id;
+	e->offset = pack_size;
+	object_count++;
+	object_count_by_type[type]++;
+
+	if (delta) {
+		unsigned long ofs = e->offset - last->offset;
+		unsigned pos = sizeof(hdr) - 1;
+
+		delta_count_by_type[type]++;
+		last->depth++;
+
+		hdrlen = encode_header(OBJ_OFS_DELTA, deltalen, hdr);
+		write_or_die(pack_data->pack_fd, hdr, hdrlen);
+		pack_size += hdrlen;
+
+		hdr[pos] = ofs & 127;
+		while (ofs >>= 7)
+			hdr[--pos] = 128 | (--ofs & 127);
+		write_or_die(pack_data->pack_fd, hdr + pos, sizeof(hdr) - pos);
+		pack_size += sizeof(hdr) - pos;
+	} else {
+		if (last)
+			last->depth = 0;
+		hdrlen = encode_header(type, datlen, hdr);
+		write_or_die(pack_data->pack_fd, hdr, hdrlen);
+		pack_size += hdrlen;
+	}
+
+	write_or_die(pack_data->pack_fd, out, s.total_out);
 	pack_size += s.total_out;
 
 	free(out);
 	if (delta)
 		free(delta);
 	if (last) {
-		if (last->data)
+		if (last->data && !last->no_free)
 			free(last->data);
 		last->data = dat;
+		last->offset = e->offset;
 		last->len = datlen;
-		memcpy(last->sha1, sha1, sizeof(sha1));
 	}
 	return 0;
 }
 
-static void* map_pack(unsigned long offset)
-{
-	if (offset >= pack_size)
-		die("object offset outside of pack file");
-	if (offset >= pack_mlen) {
-		if (pack_base)
-			munmap(pack_base, pack_mlen);
-		/* round out how much we map to 16 MB units */
-		pack_mlen = pack_size;
-		if (pack_mlen & ((1 << 24) - 1))
-			pack_mlen = ((pack_mlen >> 24) + 1) << 24;
-		pack_base = mmap(NULL,pack_mlen,PROT_READ,MAP_SHARED,pack_fd,0);
-		if (pack_base == MAP_FAILED)
-			die("Failed to map generated pack: %s", strerror(errno));
-		remap_count++;
-	}
-	return (char*)pack_base + offset;
-}
-
-static unsigned long unpack_object_header(unsigned long offset,
-	enum object_type *type,
-	unsigned long *sizep)
-{
-	unsigned shift;
-	unsigned char c;
-	unsigned long size;
-
-	c = *(unsigned char*)map_pack(offset++);
-	*type = (c >> 4) & 7;
-	size = c & 15;
-	shift = 4;
-	while (c & 0x80) {
-		c = *(unsigned char*)map_pack(offset++);
-		size += (c & 0x7f) << shift;
-		shift += 7;
-	}
-	*sizep = size;
-	return offset;
-}
-
-static void *unpack_non_delta_entry(unsigned long o, unsigned long sz)
-{
-	z_stream stream;
-	unsigned char *result;
-
-	result = xmalloc(sz + 1);
-	result[sz] = 0;
-
-	memset(&stream, 0, sizeof(stream));
-	stream.next_in = map_pack(o);
-	stream.avail_in = pack_mlen - o;
-	stream.next_out = result;
-	stream.avail_out = sz;
-
-	inflateInit(&stream);
-	for (;;) {
-		int st = inflate(&stream, Z_FINISH);
-		if (st == Z_STREAM_END)
-			break;
-		if (st == Z_OK) {
-			o = stream.next_in - (unsigned char*)pack_base;
-			stream.next_in = map_pack(o);
-			stream.avail_in = pack_mlen - o;
-			continue;
-		}
-		die("Error from zlib during inflate.");
-	}
-	inflateEnd(&stream);
-	if (stream.total_out != sz)
-		die("Error after inflate: sizes mismatch");
-	return result;
-}
-
-static void *unpack_entry(unsigned long offset, unsigned long *sizep);
-
-static void *unpack_delta_entry(unsigned long offset,
-	unsigned long delta_size,
+static void *gfi_unpack_entry(
+	struct object_entry *oe,
 	unsigned long *sizep)
 {
-	struct object_entry *base_oe;
-	unsigned char *base_sha1;
-	void *delta_data, *base, *result;
-	unsigned long base_size, result_size;
-
-	base_sha1 = (unsigned char*)map_pack(offset + 20) - 20;
-	base_oe = find_object(base_sha1);
-	if (!base_oe)
-		die("I'm broken; I can't find a base I know must be here.");
-	base = unpack_entry(base_oe->offset, &base_size);
-	delta_data = unpack_non_delta_entry(offset + 20, delta_size);
-	result = patch_delta(base, base_size,
-			     delta_data, delta_size,
-			     &result_size);
-	if (!result)
-		die("failed to apply delta");
-	free(delta_data);
-	free(base);
-	*sizep = result_size;
-	return result;
-}
-
-static void *unpack_entry(unsigned long offset, unsigned long *sizep)
-{
-	unsigned long size;
-	enum object_type kind;
-
-	offset = unpack_object_header(offset, &kind, &size);
-	switch (kind) {
-	case OBJ_DELTA:
-		return unpack_delta_entry(offset, size, sizep);
-	case OBJ_COMMIT:
-	case OBJ_TREE:
-	case OBJ_BLOB:
-	case OBJ_TAG:
-		*sizep = size;
-		return unpack_non_delta_entry(offset, size);
-	default:
-		die("I created an object I can't read!");
-	}
+	static char type[20];
+	struct packed_git *p = all_packs[oe->pack_id];
+	if (p == pack_data)
+		p->pack_size = pack_size + 20;
+	return unpack_entry(p, oe->offset, type, sizep);
 }
 
 static const char *get_mode(const char *str, unsigned int *modep)
@@ -813,6 +993,7 @@ static const char *get_mode(const char *str, unsigned int *modep)
 
 static void load_tree(struct tree_entry *root)
 {
+	unsigned char* sha1 = root->versions[1].sha1;
 	struct object_entry *myoe;
 	struct tree_content *t;
 	unsigned long size;
@@ -820,19 +1001,20 @@ static void load_tree(struct tree_entry *root)
 	const char *c;
 
 	root->tree = t = new_tree_content(8);
-	if (!memcmp(root->sha1, null_sha1, 20))
+	if (is_null_sha1(sha1))
 		return;
 
-	myoe = find_object(root->sha1);
+	myoe = find_object(sha1);
 	if (myoe) {
 		if (myoe->type != OBJ_TREE)
-			die("Not a tree: %s", sha1_to_hex(root->sha1));
-		buf = unpack_entry(myoe->offset, &size);
+			die("Not a tree: %s", sha1_to_hex(sha1));
+		t->delta_depth = 0;
+		buf = gfi_unpack_entry(myoe, &size);
 	} else {
 		char type[20];
-		buf = read_sha1_file(root->sha1, type, &size);
+		buf = read_sha1_file(sha1, type, &size);
 		if (!buf || strcmp(type, tree_type))
-			die("Can't load tree %s", sha1_to_hex(root->sha1));
+			die("Can't load tree %s", sha1_to_hex(sha1));
 	}
 
 	c = buf;
@@ -844,56 +1026,119 @@ static void load_tree(struct tree_entry *root)
 		t->entries[t->entry_count++] = e;
 
 		e->tree = NULL;
-		c = get_mode(c, &e->mode);
+		c = get_mode(c, &e->versions[1].mode);
 		if (!c)
-			die("Corrupt mode in %s", sha1_to_hex(root->sha1));
+			die("Corrupt mode in %s", sha1_to_hex(sha1));
+		e->versions[0].mode = e->versions[1].mode;
 		e->name = to_atom(c, strlen(c));
 		c += e->name->str_len + 1;
-		memcpy(e->sha1, c, sizeof(e->sha1));
+		hashcpy(e->versions[0].sha1, (unsigned char*)c);
+		hashcpy(e->versions[1].sha1, (unsigned char*)c);
 		c += 20;
 	}
 	free(buf);
 }
 
-static int tecmp (const void *_a, const void *_b)
+static int tecmp0 (const void *_a, const void *_b)
 {
 	struct tree_entry *a = *((struct tree_entry**)_a);
 	struct tree_entry *b = *((struct tree_entry**)_b);
 	return base_name_compare(
-		a->name->str_dat, a->name->str_len, a->mode,
-		b->name->str_dat, b->name->str_len, b->mode);
+		a->name->str_dat, a->name->str_len, a->versions[0].mode,
+		b->name->str_dat, b->name->str_len, b->versions[0].mode);
 }
 
-static void store_tree(struct tree_entry *root)
+static int tecmp1 (const void *_a, const void *_b)
 {
-	struct tree_content *t = root->tree;
+	struct tree_entry *a = *((struct tree_entry**)_a);
+	struct tree_entry *b = *((struct tree_entry**)_b);
+	return base_name_compare(
+		a->name->str_dat, a->name->str_len, a->versions[1].mode,
+		b->name->str_dat, b->name->str_len, b->versions[1].mode);
+}
+
+static void mktree(struct tree_content *t,
+	int v,
+	unsigned long *szp,
+	struct dbuf *b)
+{
+	size_t maxlen = 0;
 	unsigned int i;
-	size_t maxlen;
-	char *buf, *c;
+	char *c;
 
-	if (memcmp(root->sha1, null_sha1, 20))
-		return;
+	if (!v)
+		qsort(t->entries,t->entry_count,sizeof(t->entries[0]),tecmp0);
+	else
+		qsort(t->entries,t->entry_count,sizeof(t->entries[0]),tecmp1);
 
-	maxlen = 0;
 	for (i = 0; i < t->entry_count; i++) {
-		maxlen += t->entries[i]->name->str_len + 34;
-		if (t->entries[i]->tree)
-			store_tree(t->entries[i]);
+		if (t->entries[i]->versions[v].mode)
+			maxlen += t->entries[i]->name->str_len + 34;
 	}
 
-	qsort(t->entries, t->entry_count, sizeof(t->entries[0]), tecmp);
-	buf = c = xmalloc(maxlen);
+	size_dbuf(b, maxlen);
+	c = b->buffer;
 	for (i = 0; i < t->entry_count; i++) {
 		struct tree_entry *e = t->entries[i];
-		c += sprintf(c, "%o", e->mode);
+		if (!e->versions[v].mode)
+			continue;
+		c += sprintf(c, "%o", e->versions[v].mode);
 		*c++ = ' ';
 		strcpy(c, e->name->str_dat);
 		c += e->name->str_len + 1;
-		memcpy(c, e->sha1, 20);
+		hashcpy((unsigned char*)c, e->versions[v].sha1);
 		c += 20;
 	}
-	store_object(OBJ_TREE, buf, c - buf, NULL, root->sha1, 0);
-	free(buf);
+	*szp = c - (char*)b->buffer;
+}
+
+static void store_tree(struct tree_entry *root)
+{
+	struct tree_content *t = root->tree;
+	unsigned int i, j, del;
+	unsigned long new_len;
+	struct last_object lo;
+	struct object_entry *le;
+
+	if (!is_null_sha1(root->versions[1].sha1))
+		return;
+
+	for (i = 0; i < t->entry_count; i++) {
+		if (t->entries[i]->tree)
+			store_tree(t->entries[i]);
+	}
+
+	le = find_object(root->versions[0].sha1);
+	if (!S_ISDIR(root->versions[0].mode)
+		|| !le
+		|| le->pack_id != pack_id) {
+		lo.data = NULL;
+		lo.depth = 0;
+	} else {
+		mktree(t, 0, &lo.len, &old_tree);
+		lo.data = old_tree.buffer;
+		lo.offset = le->offset;
+		lo.depth = t->delta_depth;
+		lo.no_free = 1;
+	}
+
+	mktree(t, 1, &new_len, &new_tree);
+	store_object(OBJ_TREE, new_tree.buffer, new_len,
+		&lo, root->versions[1].sha1, 0);
+
+	t->delta_depth = lo.depth;
+	for (i = 0, j = 0, del = 0; i < t->entry_count; i++) {
+		struct tree_entry *e = t->entries[i];
+		if (e->versions[1].mode) {
+			e->versions[0].mode = e->versions[1].mode;
+			hashcpy(e->versions[0].sha1, e->versions[1].sha1);
+			t->entries[j++] = e;
+		} else {
+			release_tree_entry(e);
+			del++;
+		}
+	}
+	t->entry_count -= del;
 }
 
 static int tree_content_set(
@@ -917,25 +1162,26 @@ static int tree_content_set(
 		e = t->entries[i];
 		if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
 			if (!slash1) {
-				if (e->mode == mode && !memcmp(e->sha1, sha1, 20))
+				if (e->versions[1].mode == mode
+						&& !hashcmp(e->versions[1].sha1, sha1))
 					return 0;
-				e->mode = mode;
-				memcpy(e->sha1, sha1, 20);
+				e->versions[1].mode = mode;
+				hashcpy(e->versions[1].sha1, sha1);
 				if (e->tree) {
 					release_tree_content_recursive(e->tree);
 					e->tree = NULL;
 				}
-				memcpy(root->sha1, null_sha1, 20);
+				hashclr(root->versions[1].sha1);
 				return 1;
 			}
-			if (!S_ISDIR(e->mode)) {
+			if (!S_ISDIR(e->versions[1].mode)) {
 				e->tree = new_tree_content(8);
-				e->mode = S_IFDIR;
+				e->versions[1].mode = S_IFDIR;
 			}
 			if (!e->tree)
 				load_tree(e);
 			if (tree_content_set(e, slash1 + 1, sha1, mode)) {
-				memcpy(root->sha1, null_sha1, 20);
+				hashclr(root->versions[1].sha1);
 				return 1;
 			}
 			return 0;
@@ -946,17 +1192,19 @@ static int tree_content_set(
 		root->tree = t = grow_tree_content(t, 8);
 	e = new_tree_entry();
 	e->name = to_atom(p, n);
+	e->versions[0].mode = 0;
+	hashclr(e->versions[0].sha1);
 	t->entries[t->entry_count++] = e;
 	if (slash1) {
 		e->tree = new_tree_content(8);
-		e->mode = S_IFDIR;
+		e->versions[1].mode = S_IFDIR;
 		tree_content_set(e, slash1 + 1, sha1, mode);
 	} else {
 		e->tree = NULL;
-		e->mode = mode;
-		memcpy(e->sha1, sha1, 20);
+		e->versions[1].mode = mode;
+		hashcpy(e->versions[1].sha1, sha1);
 	}
-	memcpy(root->sha1, null_sha1, 20);
+	hashclr(root->versions[1].sha1);
 	return 1;
 }
 
@@ -976,15 +1224,18 @@ static int tree_content_remove(struct tree_entry *root, const char *p)
 	for (i = 0; i < t->entry_count; i++) {
 		e = t->entries[i];
 		if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
-			if (!slash1 || !S_ISDIR(e->mode))
+			if (!slash1 || !S_ISDIR(e->versions[1].mode))
 				goto del_entry;
 			if (!e->tree)
 				load_tree(e);
 			if (tree_content_remove(e, slash1 + 1)) {
-				if (!e->tree->entry_count)
-					goto del_entry;
-				memcpy(root->sha1, null_sha1, 20);
-				return 1;
+				for (n = 0; n < e->tree->entry_count; n++) {
+					if (e->tree->entries[n]->versions[1].mode) {
+						hashclr(root->versions[1].sha1);
+						return 1;
+					}
+				}
+				goto del_entry;
 			}
 			return 0;
 		}
@@ -992,106 +1243,14 @@ static int tree_content_remove(struct tree_entry *root, const char *p)
 	return 0;
 
 del_entry:
-	for (i++; i < t->entry_count; i++)
-		t->entries[i-1] = t->entries[i];
-	t->entry_count--;
-	release_tree_entry(e);
-	memcpy(root->sha1, null_sha1, 20);
-	return 1;
-}
-
-static void init_pack_header()
-{
-	struct pack_header hdr;
-
-	hdr.hdr_signature = htonl(PACK_SIGNATURE);
-	hdr.hdr_version = htonl(2);
-	hdr.hdr_entries = 0;
-
-	ywrite(pack_fd, &hdr, sizeof(hdr));
-	pack_size = sizeof(hdr);
-}
-
-static void fixup_header_footer()
-{
-	SHA_CTX c;
-	char hdr[8];
-	unsigned long cnt;
-	char *buf;
-	size_t n;
-
-	if (lseek(pack_fd, 0, SEEK_SET) != 0)
-		die("Failed seeking to start: %s", strerror(errno));
-
-	SHA1_Init(&c);
-	yread(pack_fd, hdr, 8);
-	SHA1_Update(&c, hdr, 8);
-
-	cnt = htonl(object_count);
-	SHA1_Update(&c, &cnt, 4);
-	ywrite(pack_fd, &cnt, 4);
-
-	buf = xmalloc(128 * 1024);
-	for (;;) {
-		n = xread(pack_fd, buf, 128 * 1024);
-		if (n <= 0)
-			break;
-		SHA1_Update(&c, buf, n);
-	}
-	free(buf);
-
-	SHA1_Final(pack_sha1, &c);
-	ywrite(pack_fd, pack_sha1, sizeof(pack_sha1));
-}
-
-static int oecmp (const void *_a, const void *_b)
-{
-	struct object_entry *a = *((struct object_entry**)_a);
-	struct object_entry *b = *((struct object_entry**)_b);
-	return memcmp(a->sha1, b->sha1, sizeof(a->sha1));
-}
-
-static void write_index(const char *idx_name)
-{
-	struct sha1file *f;
-	struct object_entry **idx, **c, **last;
-	struct object_entry *e;
-	struct object_entry_pool *o;
-	unsigned int array[256];
-	int i;
-
-	/* Build the sorted table of object IDs. */
-	idx = xmalloc(object_count * sizeof(struct object_entry*));
-	c = idx;
-	for (o = blocks; o; o = o->next_pool)
-		for (e = o->entries; e != o->next_free; e++)
-			*c++ = e;
-	last = idx + object_count;
-	qsort(idx, object_count, sizeof(struct object_entry*), oecmp);
-
-	/* Generate the fan-out array. */
-	c = idx;
-	for (i = 0; i < 256; i++) {
-		struct object_entry **next = c;;
-		while (next < last) {
-			if ((*next)->sha1[0] != i)
-				break;
-			next++;
-		}
-		array[i] = htonl(next - idx);
-		c = next;
-	}
-
-	f = sha1create("%s", idx_name);
-	sha1write(f, array, 256 * sizeof(int));
-	for (c = idx; c != last; c++) {
-		unsigned int offset = htonl((*c)->offset);
-		sha1write(f, &offset, 4);
-		sha1write(f, (*c)->sha1, sizeof((*c)->sha1));
+	if (e->tree) {
+		release_tree_content_recursive(e->tree);
+		e->tree = NULL;
 	}
-	sha1write(f, pack_sha1, sizeof(pack_sha1));
-	sha1close(f, NULL, 1);
-	free(idx);
+	e->versions[1].mode = 0;
+	hashclr(e->versions[1].sha1);
+	hashclr(root->versions[1].sha1);
+	return 1;
 }
 
 static void dump_branches()
@@ -1103,7 +1262,7 @@ static void dump_branches()
 
 	for (i = 0; i < branch_table_sz; i++) {
 		for (b = branch_table[i]; b; b = b->table_next_branch) {
-			lock = lock_any_ref_for_update(b->name, NULL, 0);
+			lock = lock_any_ref_for_update(b->name, NULL);
 			if (!lock || write_ref_sha1(lock, b->sha1, msg) < 0)
 				die("Can't write %s", b->name);
 		}
@@ -1119,17 +1278,17 @@ static void dump_tags()
 
 	for (t = first_tag; t; t = t->next_tag) {
 		sprintf(path, "refs/tags/%s", t->name);
-		lock = lock_any_ref_for_update(path, NULL, 0);
+		lock = lock_any_ref_for_update(path, NULL);
 		if (!lock || write_ref_sha1(lock, t->sha1, msg) < 0)
 			die("Can't write %s", path);
 	}
 }
 
 static void dump_marks_helper(FILE *f,
-	unsigned long base,
+	uintmax_t base,
 	struct mark_set *m)
 {
-	int k;
+	uintmax_t k;
 	if (m->shift) {
 		for (k = 0; k < 1024; k++) {
 			if (m->data.sets[k])
@@ -1139,7 +1298,7 @@ static void dump_marks_helper(FILE *f,
 	} else {
 		for (k = 0; k < 1024; k++) {
 			if (m->data.marked[k])
-				fprintf(f, ":%lu %s\n", base + k,
+				fprintf(f, ":%ju %s\n", base + k,
 					sha1_to_hex(m->data.marked[k]->sha1));
 		}
 	}
@@ -1163,7 +1322,7 @@ static void read_next_command()
 static void cmd_mark()
 {
 	if (!strncmp("mark :", command_buf.buf, 6)) {
-		next_mark = strtoul(command_buf.buf + 6, NULL, 10);
+		next_mark = strtoumax(command_buf.buf + 6, NULL, 10);
 		read_next_command();
 	}
 	else
@@ -1276,7 +1435,8 @@ static void file_change_m(struct branch *b)
 
 	if (*p == ':') {
 		char *x;
-		oe = find_mark(strtoul(p + 1, &x, 10));
+		oe = find_mark(strtoumax(p + 1, &x, 10));
+		hashcpy(sha1, oe->sha1);
 		p = x;
 	} else {
 		if (get_sha1_hex(p, sha1))
@@ -1353,27 +1513,32 @@ static void cmd_from(struct branch *b)
 	if (b == s)
 		die("Can't create a branch from itself: %s", b->name);
 	else if (s) {
-		memcpy(b->sha1, s->sha1, 20);
-		memcpy(b->branch_tree.sha1, s->branch_tree.sha1, 20);
+		unsigned char *t = s->branch_tree.versions[1].sha1;
+		hashcpy(b->sha1, s->sha1);
+		hashcpy(b->branch_tree.versions[0].sha1, t);
+		hashcpy(b->branch_tree.versions[1].sha1, t);
 	} else if (*from == ':') {
-		unsigned long idnum = strtoul(from + 1, NULL, 10);
+		uintmax_t idnum = strtoumax(from + 1, NULL, 10);
 		struct object_entry *oe = find_mark(idnum);
 		unsigned long size;
 		char *buf;
 		if (oe->type != OBJ_COMMIT)
-			die("Mark :%lu not a commit", idnum);
-		memcpy(b->sha1, oe->sha1, 20);
-		buf = unpack_entry(oe->offset, &size);
+			die("Mark :%ju not a commit", idnum);
+		hashcpy(b->sha1, oe->sha1);
+		buf = gfi_unpack_entry(oe, &size);
 		if (!buf || size < 46)
 			die("Not a valid commit: %s", from);
 		if (memcmp("tree ", buf, 5)
-			|| get_sha1_hex(buf + 5, b->branch_tree.sha1))
+			|| get_sha1_hex(buf + 5, b->branch_tree.versions[1].sha1))
 			die("The commit %s is corrupt", sha1_to_hex(b->sha1));
 		free(buf);
+		hashcpy(b->branch_tree.versions[0].sha1,
+			b->branch_tree.versions[1].sha1);
 	} else if (!get_sha1(from, b->sha1)) {
-		if (!memcmp(b->sha1, null_sha1, 20))
-			memcpy(b->branch_tree.sha1, null_sha1, 20);
-		else {
+		if (is_null_sha1(b->sha1)) {
+			hashclr(b->branch_tree.versions[0].sha1);
+			hashclr(b->branch_tree.versions[1].sha1);
+		} else {
 			unsigned long size;
 			char *buf;
 
@@ -1382,9 +1547,11 @@ static void cmd_from(struct branch *b)
 			if (!buf || size < 46)
 				die("Not a valid commit: %s", from);
 			if (memcmp("tree ", buf, 5)
-				|| get_sha1_hex(buf + 5, b->branch_tree.sha1))
+				|| get_sha1_hex(buf + 5, b->branch_tree.versions[1].sha1))
 				die("The commit %s is corrupt", sha1_to_hex(b->sha1));
 			free(buf);
+			hashcpy(b->branch_tree.versions[0].sha1,
+				b->branch_tree.versions[1].sha1);
 		}
 	} else
 		die("Invalid ref name or SHA1 expression: %s", from);
@@ -1392,6 +1559,48 @@ static void cmd_from(struct branch *b)
 	read_next_command();
 }
 
+static struct hash_list* cmd_merge(unsigned int *count)
+{
+	struct hash_list *list = NULL, *n, *e;
+	const char *from, *endp;
+	char *str_uq;
+	struct branch *s;
+
+	*count = 0;
+	while (!strncmp("merge ", command_buf.buf, 6)) {
+		from = strchr(command_buf.buf, ' ') + 1;
+		str_uq = unquote_c_style(from, &endp);
+		if (str_uq) {
+			if (*endp)
+				die("Garbage after string in: %s", command_buf.buf);
+			from = str_uq;
+		}
+
+		n = xmalloc(sizeof(*n));
+		s = lookup_branch(from);
+		if (s)
+			hashcpy(n->sha1, s->sha1);
+		else if (*from == ':') {
+			uintmax_t idnum = strtoumax(from + 1, NULL, 10);
+			struct object_entry *oe = find_mark(idnum);
+			if (oe->type != OBJ_COMMIT)
+				die("Mark :%ju not a commit", idnum);
+			hashcpy(n->sha1, oe->sha1);
+		} else if (get_sha1(from, n->sha1))
+			die("Invalid ref name or SHA1 expression: %s", from);
+
+		n->next = NULL;
+		if (list)
+			e->next = n;
+		else
+			list = n;
+		e = n;
+		*count++;
+		read_next_command();
+	}
+	return list;
+}
+
 static void cmd_new_commit()
 {
 	struct branch *b;
@@ -1402,7 +1611,8 @@ static void cmd_new_commit()
 	char *sp;
 	char *author = NULL;
 	char *committer = NULL;
-	char *body;
+	struct hash_list *merge_list = NULL;
+	unsigned int merge_count;
 
 	/* Obtain the branch name from the rest of our command */
 	sp = strchr(command_buf.buf, ' ') + 1;
@@ -1433,6 +1643,7 @@ static void cmd_new_commit()
 	msg = cmd_data(&msglen);
 	read_next_command();
 	cmd_from(b);
+	merge_list = cmd_merge(&merge_count);
 
 	/* ensure the branch is active/loaded */
 	if (!b->branch_tree.tree || !max_active_branches) {
@@ -1455,14 +1666,24 @@ static void cmd_new_commit()
 
 	/* build the tree and the commit */
 	store_tree(&b->branch_tree);
-	body = xmalloc(97 + msglen
+	hashcpy(b->branch_tree.versions[0].sha1,
+		b->branch_tree.versions[1].sha1);
+	size_dbuf(&new_data, 97 + msglen
+		+ merge_count * 49
 		+ (author
 			? strlen(author) + strlen(committer)
 			: 2 * strlen(committer)));
-	sp = body;
-	sp += sprintf(sp, "tree %s\n", sha1_to_hex(b->branch_tree.sha1));
-	if (memcmp(b->sha1, null_sha1, 20))
+	sp = new_data.buffer;
+	sp += sprintf(sp, "tree %s\n",
+		sha1_to_hex(b->branch_tree.versions[1].sha1));
+	if (!is_null_sha1(b->sha1))
 		sp += sprintf(sp, "parent %s\n", sha1_to_hex(b->sha1));
+	while (merge_list) {
+		struct hash_list *next = merge_list->next;
+		sp += sprintf(sp, "parent %s\n", sha1_to_hex(merge_list->sha1));
+		free(merge_list);
+		merge_list = next;
+	}
 	if (author)
 		sp += sprintf(sp, "%s\n", author);
 	else
@@ -1475,9 +1696,11 @@ static void cmd_new_commit()
 	free(committer);
 	free(msg);
 
-	store_object(OBJ_COMMIT, body, sp - body, NULL, b->sha1, next_mark);
-	free(body);
+	store_object(OBJ_COMMIT,
+		new_data.buffer, sp - (char*)new_data.buffer,
+		NULL, b->sha1, next_mark);
 	b->last_commit = object_count_by_type[OBJ_COMMIT];
+	b->pack_id = pack_id;
 
 	if (branch_log) {
 		int need_dq = quote_c_style(b->name, NULL, NULL, 0);
@@ -1488,7 +1711,7 @@ static void cmd_new_commit()
 			fputc('"', branch_log);
 		} else
 			fprintf(branch_log, "%s", b->name);
-		fprintf(branch_log," :%lu %s\n",next_mark,sha1_to_hex(b->sha1));
+		fprintf(branch_log," :%ju %s\n",next_mark,sha1_to_hex(b->sha1));
 	}
 }
 
@@ -1502,9 +1725,8 @@ static void cmd_new_tag()
 	struct branch *s;
 	void *msg;
 	size_t msglen;
-	char *body;
 	struct tag *t;
-	unsigned long from_mark = 0;
+	uintmax_t from_mark = 0;
 	unsigned char sha1[20];
 
 	/* Obtain the new tag name from the rest of our command */
@@ -1541,13 +1763,13 @@ static void cmd_new_tag()
 
 	s = lookup_branch(from);
 	if (s) {
-		memcpy(sha1, s->sha1, 20);
+		hashcpy(sha1, s->sha1);
 	} else if (*from == ':') {
-		from_mark = strtoul(from + 1, NULL, 10);
+		from_mark = strtoumax(from + 1, NULL, 10);
 		struct object_entry *oe = find_mark(from_mark);
 		if (oe->type != OBJ_COMMIT)
-			die("Mark :%lu not a commit", from_mark);
-		memcpy(sha1, oe->sha1, 20);
+			die("Mark :%ju not a commit", from_mark);
+		hashcpy(sha1, oe->sha1);
 	} else if (!get_sha1(from, sha1)) {
 		unsigned long size;
 		char *buf;
@@ -1574,8 +1796,8 @@ static void cmd_new_tag()
 	msg = cmd_data(&msglen);
 
 	/* build the tag object */
-	body = xmalloc(67 + strlen(t->name) + strlen(tagger) + msglen);
-	sp = body;
+	size_dbuf(&new_data, 67+strlen(t->name)+strlen(tagger)+msglen);
+	sp = new_data.buffer;
 	sp += sprintf(sp, "object %s\n", sha1_to_hex(sha1));
 	sp += sprintf(sp, "type %s\n", type_names[OBJ_COMMIT]);
 	sp += sprintf(sp, "tag %s\n", t->name);
@@ -1585,8 +1807,9 @@ static void cmd_new_tag()
 	free(tagger);
 	free(msg);
 
-	store_object(OBJ_TAG, body, sp - body, NULL, t->sha1, 0);
-	free(body);
+	store_object(OBJ_TAG, new_data.buffer, sp - (char*)new_data.buffer,
+		NULL, t->sha1, 0);
+	t->pack_id = pack_id;
 
 	if (branch_log) {
 		int need_dq = quote_c_style(t->name, NULL, NULL, 0);
@@ -1597,21 +1820,56 @@ static void cmd_new_tag()
 			fputc('"', branch_log);
 		} else
 			fprintf(branch_log, "%s", t->name);
-		fprintf(branch_log," :%lu %s\n",from_mark,sha1_to_hex(t->sha1));
+		fprintf(branch_log," :%ju %s\n",from_mark,sha1_to_hex(t->sha1));
 	}
 }
 
+static void cmd_reset_branch()
+{
+	struct branch *b;
+	char *str_uq;
+	const char *endp;
+	char *sp;
+
+	/* Obtain the branch name from the rest of our command */
+	sp = strchr(command_buf.buf, ' ') + 1;
+	str_uq = unquote_c_style(sp, &endp);
+	if (str_uq) {
+		if (*endp)
+			die("Garbage after ref in: %s", command_buf.buf);
+		sp = str_uq;
+	}
+	b = lookup_branch(sp);
+	if (b) {
+		b->last_commit = 0;
+		if (b->branch_tree.tree) {
+			release_tree_content_recursive(b->branch_tree.tree);
+			b->branch_tree.tree = NULL;
+		}
+	}
+	else
+		b = new_branch(sp);
+	if (str_uq)
+		free(str_uq);
+	read_next_command();
+	cmd_from(b);
+}
+
+static void cmd_checkpoint()
+{
+	if (object_count)
+		checkpoint();
+	read_next_command();
+}
+
 static const char fast_import_usage[] =
-"git-fast-import [--objects=n] [--depth=n] [--active-branches=n] [--export-marks=marks.file] [--branch-log=log] temp.pack";
+"git-fast-import [--objects=n] [--depth=n] [--active-branches=n] [--export-marks=marks.file] [--branch-log=log]";
 
 int main(int argc, const char **argv)
 {
-	const char *base_name;
 	int i;
-	unsigned long est_obj_cnt = 1000;
-	char *pack_name;
-	char *idx_name;
-	struct stat sb;
+	uintmax_t est_obj_cnt = object_entry_alloc;
+	uintmax_t total_count, duplicate_count;
 
 	setup_ident();
 	git_config(git_default_config);
@@ -1622,7 +1880,11 @@ int main(int argc, const char **argv)
 		if (*a != '-' || !strcmp(a, "--"))
 			break;
 		else if (!strncmp(a, "--objects=", 10))
-			est_obj_cnt = strtoul(a + 10, NULL, 0);
+			est_obj_cnt = strtoumax(a + 10, NULL, 0);
+		else if (!strncmp(a, "--max-objects-per-pack=", 23))
+			max_objects = strtoumax(a + 23, NULL, 0);
+		else if (!strncmp(a, "--max-pack-size=", 16))
+			max_packsize = strtoumax(a + 16, NULL, 0) * 1024 * 1024;
 		else if (!strncmp(a, "--depth=", 8))
 			max_depth = strtoul(a + 8, NULL, 0);
 		else if (!strncmp(a, "--active-branches=", 18))
@@ -1637,20 +1899,9 @@ int main(int argc, const char **argv)
 		else
 			die("unknown option %s", a);
 	}
-	if ((i+1) != argc)
+	if (i != argc)
 		usage(fast_import_usage);
-	base_name = argv[i];
-
-	pack_name = xmalloc(strlen(base_name) + 6);
-	sprintf(pack_name, "%s.pack", base_name);
-	idx_name = xmalloc(strlen(base_name) + 5);
-	sprintf(idx_name, "%s.idx", base_name);
-
-	pack_fd = open(pack_name, O_RDWR|O_CREAT|O_EXCL, 0666);
-	if (pack_fd < 0)
-		die("Can't create %s: %s", pack_name, strerror(errno));
 
-	init_pack_header();
 	alloc_objects(est_obj_cnt);
 	strbuf_init(&command_buf);
 
@@ -1659,6 +1910,7 @@ int main(int argc, const char **argv)
 	avail_tree_table = xcalloc(avail_tree_table_sz, sizeof(struct avail_tree_content*));
 	marks = pool_calloc(1, sizeof(struct mark_set));
 
+	start_packfile();
 	for (;;) {
 		read_next_command();
 		if (command_buf.eof)
@@ -1669,40 +1921,46 @@ int main(int argc, const char **argv)
 			cmd_new_commit();
 		else if (!strncmp("tag ", command_buf.buf, 4))
 			cmd_new_tag();
+		else if (!strncmp("reset ", command_buf.buf, 6))
+			cmd_reset_branch();
+		else if (!strcmp("checkpoint", command_buf.buf))
+			cmd_checkpoint();
 		else
 			die("Unsupported command: %s", command_buf.buf);
 	}
+	end_packfile();
 
-	fixup_header_footer();
-	close(pack_fd);
-	write_index(idx_name);
 	dump_branches();
 	dump_tags();
+	unkeep_all_packs();
 	dump_marks();
-	fclose(branch_log);
+	if (branch_log)
+		fclose(branch_log);
+
+	total_count = 0;
+	for (i = 0; i < ARRAY_SIZE(object_count_by_type); i++)
+		total_count += object_count_by_type[i];
+	duplicate_count = 0;
+	for (i = 0; i < ARRAY_SIZE(duplicate_count_by_type); i++)
+		duplicate_count += duplicate_count_by_type[i];
 
 	fprintf(stderr, "%s statistics:\n", argv[0]);
-	fprintf(stderr, "---------------------------------------------------\n");
-	fprintf(stderr, "Alloc'd objects: %10lu (%10lu overflow  )\n", alloc_count, alloc_count - est_obj_cnt);
-	fprintf(stderr, "Total objects:   %10lu (%10lu duplicates)\n", object_count, duplicate_count);
-	fprintf(stderr, "      blobs  :   %10lu (%10lu duplicates)\n", object_count_by_type[OBJ_BLOB], duplicate_count_by_type[OBJ_BLOB]);
-	fprintf(stderr, "      trees  :   %10lu (%10lu duplicates)\n", object_count_by_type[OBJ_TREE], duplicate_count_by_type[OBJ_TREE]);
-	fprintf(stderr, "      commits:   %10lu (%10lu duplicates)\n", object_count_by_type[OBJ_COMMIT], duplicate_count_by_type[OBJ_COMMIT]);
-	fprintf(stderr, "      tags   :   %10lu (%10lu duplicates)\n", object_count_by_type[OBJ_TAG], duplicate_count_by_type[OBJ_TAG]);
+	fprintf(stderr, "---------------------------------------------------------------------\n");
+	fprintf(stderr, "Alloc'd objects: %10ju (%10ju overflow  )\n", alloc_count, alloc_count - est_obj_cnt);
+	fprintf(stderr, "Total objects:   %10ju (%10ju duplicates                  )\n", total_count, duplicate_count);
+	fprintf(stderr, "      blobs  :   %10ju (%10ju duplicates %10ju deltas)\n", object_count_by_type[OBJ_BLOB], duplicate_count_by_type[OBJ_BLOB], delta_count_by_type[OBJ_BLOB]);
+	fprintf(stderr, "      trees  :   %10ju (%10ju duplicates %10ju deltas)\n", object_count_by_type[OBJ_TREE], duplicate_count_by_type[OBJ_TREE], delta_count_by_type[OBJ_TREE]);
+	fprintf(stderr, "      commits:   %10ju (%10ju duplicates %10ju deltas)\n", object_count_by_type[OBJ_COMMIT], duplicate_count_by_type[OBJ_COMMIT], delta_count_by_type[OBJ_COMMIT]);
+	fprintf(stderr, "      tags   :   %10ju (%10ju duplicates %10ju deltas)\n", object_count_by_type[OBJ_TAG], duplicate_count_by_type[OBJ_TAG], delta_count_by_type[OBJ_TAG]);
 	fprintf(stderr, "Total branches:  %10lu (%10lu loads     )\n", branch_count, branch_load_count);
-	fprintf(stderr, "      marks:     %10u (%10lu unique    )\n", (1 << marks->shift) * 1024, marks_set_count);
+	fprintf(stderr, "      marks:     %10ju (%10ju unique    )\n", (((uintmax_t)1) << marks->shift) * 1024, marks_set_count);
 	fprintf(stderr, "      atoms:     %10u\n", atom_cnt);
-	fprintf(stderr, "Memory total:    %10lu KiB\n", (total_allocd + alloc_count*sizeof(struct object_entry))/1024);
+	fprintf(stderr, "Memory total:    %10ju KiB\n", (total_allocd + alloc_count*sizeof(struct object_entry))/1024);
 	fprintf(stderr, "       pools:    %10lu KiB\n", total_allocd/1024);
-	fprintf(stderr, "     objects:    %10lu KiB\n", (alloc_count*sizeof(struct object_entry))/1024);
-	fprintf(stderr, "Pack remaps:     %10lu\n", remap_count);
-	fprintf(stderr, "---------------------------------------------------\n");
-
-	stat(pack_name, &sb);
-	fprintf(stderr, "Pack size:       %10lu KiB\n", (unsigned long)(sb.st_size/1024));
-	stat(idx_name, &sb);
-	fprintf(stderr, "Index size:      %10lu KiB\n", (unsigned long)(sb.st_size/1024));
-
+	fprintf(stderr, "     objects:    %10ju KiB\n", (alloc_count*sizeof(struct object_entry))/1024);
+	fprintf(stderr, "---------------------------------------------------------------------\n");
+	pack_report();
+	fprintf(stderr, "---------------------------------------------------------------------\n");
 	fprintf(stderr, "\n");
 
 	return 0;