Merge branch 'dh/repack' (early part)

* 'dh/repack' (early part):
  Ensure git-repack -a -d --max-pack-size=N deletes correct packs
  pack-objects: clarification & option checks for --max-pack-size
  git-repack --max-pack-size: add option parsing to enable feature
  git-repack --max-pack-size: split packs as asked by write_{object,one}()
  git-repack --max-pack-size: write_{object,one}() respect pack limit
  git-repack --max-pack-size: new file statics and code restructuring
  Alter sha1close() 3rd argument to request flush only

1 files changed, 224 insertions, 105 deletions

diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index eca130f05..e52332df9 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -16,7 +16,7 @@
 #include "progress.h"
 
 static const char pack_usage[] = "\
-git-pack-objects [{ -q | --progress | --all-progress }] \n\
+git-pack-objects [{ -q | --progress | --all-progress }] [--max-pack-size=N] \n\
 	[--local] [--incremental] [--window=N] [--depth=N] \n\
 	[--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
 	[--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
@@ -54,7 +54,8 @@ struct object_entry {
  * nice "minimum seek" order.
  */
 static struct object_entry *objects;
-static uint32_t nr_objects, nr_alloc, nr_result;
+static struct object_entry **written_list;
+static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
 
 static int non_empty;
 static int no_reuse_delta, no_reuse_object;
@@ -63,9 +64,11 @@ static int incremental;
 static int allow_ofs_delta;
 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 int window = 10;
+static uint32_t pack_size_limit;
 static int depth = 50;
 static int pack_to_stdout;
 static int num_preferred_base;
@@ -351,16 +354,31 @@ static void copy_pack_data(struct sha1file *f,
 }
 
 static unsigned long write_object(struct sha1file *f,
-				  struct object_entry *entry)
+				  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->offset == (off_t)-1 ? 0 :
+				/* otherwise double-check written to this
+				 * pack,  like we do below
+				 */
+				entry->delta->offset ? 1 : 0;
 
 	if (!pack_to_stdout)
 		crc32_begin(f);
@@ -371,7 +389,9 @@ static unsigned long write_object(struct sha1file *f,
 	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)
@@ -382,24 +402,48 @@ static unsigned long write_object(struct sha1file *f,
 				 */
 
 	if (!to_reuse) {
+		z_stream stream;
+		unsigned long maxsize;
+		void *out;
 		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) {
+		if (usable_delta) {
 			buf = delta_against(buf, size, entry);
 			size = entry->delta_size;
 			obj_type = (allow_ofs_delta && entry->delta->offset) ?
 				OBJ_OFS_DELTA : OBJ_REF_DELTA;
+		} else {
+			/*
+			 * recover real object type in case
+			 * check_object() wanted to re-use a delta,
+			 * but we couldn't since base was in previous split pack
+			 */
+			obj_type = type;
 		}
+		/* 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) {
 			/*
@@ -408,21 +452,41 @@ static unsigned long write_object(struct sha1file *f,
 			 * 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;
+			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.
 			 */
+			if (limit && hdrlen + 20 + datalen + 20 >= limit) {
+				free(out);
+				free(buf);
+				return 0;
+			}
+			sha1write(f, header, hdrlen);
 			sha1write(f, entry->delta->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, pack_compression_level);
+		sha1write(f, out, datalen);
+		free(out);
 		free(buf);
 	}
 	else {
@@ -437,20 +501,6 @@ static unsigned long write_object(struct sha1file *f,
 			reused_delta++;
 		}
 		hdrlen = encode_header(obj_type, entry->size, header);
-		sha1write(f, header, hdrlen);
-		if (obj_type == OBJ_OFS_DELTA) {
-			off_t ofs = entry->offset - entry->delta->offset;
-			unsigned pos = sizeof(header) - 1;
-			header[pos] = ofs & 127;
-			while (ofs >>= 7)
-				header[--pos] = 128 | (--ofs & 127);
-			sha1write(f, header + pos, sizeof(header) - pos);
-			hdrlen += sizeof(header) - pos;
-		} else if (obj_type == OBJ_REF_DELTA) {
-			sha1write(f, entry->delta->sha1, 20);
-			hdrlen += 20;
-		}
-
 		offset = entry->in_pack_offset;
 		revidx = find_packed_object(p, offset);
 		datalen = revidx[1].offset - offset;
@@ -459,6 +509,29 @@ static unsigned long write_object(struct sha1file *f,
 			die("bad packed object CRC for %s", sha1_to_hex(entry->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(dheader) - 1;
+			dheader[pos] = ofs & 127;
+			while (ofs >>= 7)
+				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) {
+			if (limit && hdrlen + 20 + datalen + 20 >= limit)
+				return 0;
+			sha1write(f, header, hdrlen);
+			sha1write(f, entry->delta->sha1, 20);
+			hdrlen += 20;
+		} else {
+			if (limit && hdrlen + datalen + 20 >= limit)
+				return 0;
+			sha1write(f, header, hdrlen);
+		}
+
 		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->sha1));
@@ -466,7 +539,7 @@ static unsigned long write_object(struct sha1file *f,
 		unuse_pack(&w_curs);
 		reused++;
 	}
-	if (entry->delta)
+	if (usable_delta)
 		written_delta++;
 	written++;
 	if (!pack_to_stdout)
@@ -485,11 +558,19 @@ static off_t write_one(struct sha1file *f,
 		return offset;
 
 	/* if we are deltified, write out base object first. */
-	if (e->delta)
+	if (e->delta) {
 		offset = write_one(f, e->delta, offset);
+		if (!offset)
+			return 0;
+	}
 
 	e->offset = offset;
-	size = write_object(f, e);
+	size = write_object(f, e, offset);
+	if (!size) {
+		e->offset = 0;
+		return 0;
+	}
+	written_list[nr_written++] = e;
 
 	/* make sure off_t is sufficiently large not to wrap */
 	if (offset > offset + size)
@@ -503,49 +584,113 @@ static int open_object_dir_tmp(const char *path)
     return mkstemp(tmpname);
 }
 
-static off_t write_pack_file(void)
+/* forward declarations for write_pack_file */
+static void write_index_file(off_t last_obj_offset, unsigned char *sha1);
+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, last_obj_offset = 0;
+	off_t offset, offset_one, last_obj_offset = 0;
 	struct pack_header hdr;
-	int do_progress = progress;
-
-	if (pack_to_stdout) {
-		f = sha1fd(1, "<stdout>");
-		do_progress >>= 1;
-	} 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);
-	}
+	int do_progress = progress >> pack_to_stdout;
+	uint32_t nr_remaining = nr_result;
 
 	if (do_progress)
 		start_progress(&progress_state, "Writing %u objects...", "", nr_result);
+	written_list = xmalloc(nr_objects * sizeof(struct object_entry *));
 
-	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++) {
-		last_obj_offset = offset;
-		offset = write_one(f, objects + i, offset);
-		if (do_progress)
-			display_progress(&progress_state, written);
-	}
+	do {
+		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);
+		}
+
+		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;
+			offset = offset_one;
+			if (do_progress)
+				display_progress(&progress_state, written);
+		}
+
+		/*
+		 * 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, pack_file_sha1, 1);
+		} else {
+			sha1close(f, pack_file_sha1, 0);
+			fixup_pack_header_footer(f->fd, pack_file_sha1, pack_tmp_name, nr_written);
+			close(f->fd);
+		}
+
+		if (!pack_to_stdout) {
+			unsigned char object_list_sha1[20];
+			mode_t mode = umask(0);
+
+			umask(mode);
+			mode = 0444 & ~mode;
+
+			write_index_file(last_obj_offset, object_list_sha1);
+			snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
+				 base_name, sha1_to_hex(object_list_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(object_list_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(object_list_sha1));
+		}
+
+		/* mark written objects as written to previous pack */
+		for (j = 0; j < nr_written; j++) {
+			written_list[j]->offset = (off_t)-1;
+		}
+		nr_remaining -= nr_written;
+	} while (nr_remaining && i < nr_objects);
+
+	free(written_list);
 	if (do_progress)
 		stop_progress(&progress_state);
- done:
 	if (written != nr_result)
 		die("wrote %u objects while expecting %u", written, nr_result);
-	sha1close(f, pack_file_sha1, 1);
-
-	return last_obj_offset;
+	/*
+	 * 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.
+	 */
+	for (j = 0; i < nr_objects; i++) {
+		struct object_entry *e = objects + i;
+		j += !e->offset && !e->preferred_base;
+	}
+	if (j)
+		die("wrote %u objects as expected but %u unwritten", written, j);
 }
 
 static int sha1_sort(const void *_a, const void *_b)
@@ -572,18 +717,11 @@ static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
 	idx_tmp_name = xstrdup(tmpname);
 	f = sha1fd(fd, idx_tmp_name);
 
-	if (nr_result) {
-		uint32_t j = 0;
-		sorted_by_sha =
-			xcalloc(nr_result, sizeof(struct object_entry *));
-		for (i = 0; i < nr_objects; i++)
-			if (!objects[i].preferred_base)
-				sorted_by_sha[j++] = objects + i;
-		if (j != nr_result)
-			die("listed %u objects while expecting %u", j, nr_result);
-		qsort(sorted_by_sha, nr_result, sizeof(*sorted_by_sha), sha1_sort);
+	if (nr_written) {
+		sorted_by_sha = written_list;
+		qsort(sorted_by_sha, nr_written, sizeof(*sorted_by_sha), sha1_sort);
 		list = sorted_by_sha;
-		last = sorted_by_sha + nr_result;
+		last = sorted_by_sha + nr_written;
 	} else
 		sorted_by_sha = list = last = NULL;
 
@@ -621,7 +759,7 @@ static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
 
 	/* Write the actual SHA1 entries. */
 	list = sorted_by_sha;
-	for (i = 0; i < nr_result; i++) {
+	for (i = 0; i < nr_written; i++) {
 		struct object_entry *entry = *list++;
 		if (index_version < 2) {
 			uint32_t offset = htonl(entry->offset);
@@ -636,7 +774,7 @@ static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
 
 		/* write the crc32 table */
 		list = sorted_by_sha;
-		for (i = 0; i < nr_objects; i++) {
+		for (i = 0; i < nr_written; i++) {
 			struct object_entry *entry = *list++;
 			uint32_t crc32_val = htonl(entry->crc32);
 			sha1write(f, &crc32_val, 4);
@@ -644,7 +782,7 @@ static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
 
 		/* write the 32-bit offset table */
 		list = sorted_by_sha;
-		for (i = 0; i < nr_objects; i++) {
+		for (i = 0; i < nr_written; i++) {
 			struct object_entry *entry = *list++;
 			uint32_t offset = (entry->offset <= index_off32_limit) ?
 				entry->offset : (0x80000000 | nr_large_offset++);
@@ -669,7 +807,6 @@ static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
 
 	sha1write(f, pack_file_sha1, 20);
 	sha1close(f, NULL, 1);
-	free(sorted_by_sha);
 	SHA1_Final(sha1, &ctx);
 }
 
@@ -1569,8 +1706,6 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	int use_internal_rev_list = 0;
 	int thin = 0;
 	uint32_t i;
-	off_t last_obj_offset;
-	const char *base_name = NULL;
 	const char **rp_av;
 	int rp_ac_alloc = 64;
 	int rp_ac;
@@ -1616,6 +1751,13 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			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);
@@ -1714,6 +1856,9 @@ 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.");
 
@@ -1739,33 +1884,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		fprintf(stderr, "Result has %u objects.\n", nr_result);
 	if (nr_result)
 		prepare_pack(window, depth);
-	last_obj_offset = write_pack_file();
-	if (!pack_to_stdout) {
-		unsigned char object_list_sha1[20];
-		mode_t mode = umask(0);
-
-		umask(mode);
-		mode = 0444 & ~mode;
-
-		write_index_file(last_obj_offset, object_list_sha1);
-		snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
-			 base_name, sha1_to_hex(object_list_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(object_list_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(object_list_sha1));
-	}
+	write_pack_file();
 	if (progress)
 		fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
 			written, written_delta, reused, reused_delta);