archive-zip.c - git - Git at Google

 /*
  * Copyright (c) 2006 Rene Scharfe
  */
 #include "cache.h"
 #include "archive.h"
 #include "streaming.h"
 #include "utf8.h"

 static int zip_date;
 static int zip_time;

 static unsigned char *zip_dir;
 static unsigned int zip_dir_size;

 static unsigned int zip_offset;
 static unsigned int zip_dir_offset;
 static unsigned int zip_dir_entries;

 #define ZIP_DIRECTORY_MIN_SIZE	(1024 * 1024)
 #define ZIP_STREAM	(1 <<  3)
 #define ZIP_UTF8	(1 << 11)

 struct zip_local_header {
 	unsigned char magic[4];
 	unsigned char version[2];
 	unsigned char flags[2];
 	unsigned char compression_method[2];
 	unsigned char mtime[2];
 	unsigned char mdate[2];
 	unsigned char crc32[4];
 	unsigned char compressed_size[4];
 	unsigned char size[4];
 	unsigned char filename_length[2];
 	unsigned char extra_length[2];
 	unsigned char _end[1];
 };

 struct zip_data_desc {
 	unsigned char magic[4];
 	unsigned char crc32[4];
 	unsigned char compressed_size[4];
 	unsigned char size[4];
 	unsigned char _end[1];
 };

 struct zip_dir_header {
 	unsigned char magic[4];
 	unsigned char creator_version[2];
 	unsigned char version[2];
 	unsigned char flags[2];
 	unsigned char compression_method[2];
 	unsigned char mtime[2];
 	unsigned char mdate[2];
 	unsigned char crc32[4];
 	unsigned char compressed_size[4];
 	unsigned char size[4];
 	unsigned char filename_length[2];
 	unsigned char extra_length[2];
 	unsigned char comment_length[2];
 	unsigned char disk[2];
 	unsigned char attr1[2];
 	unsigned char attr2[4];
 	unsigned char offset[4];
 	unsigned char _end[1];
 };

 struct zip_dir_trailer {
 	unsigned char magic[4];
 	unsigned char disk[2];
 	unsigned char directory_start_disk[2];
 	unsigned char entries_on_this_disk[2];
 	unsigned char entries[2];
 	unsigned char size[4];
 	unsigned char offset[4];
 	unsigned char comment_length[2];
 	unsigned char _end[1];
 };

 struct zip_extra_mtime {
 	unsigned char magic[2];
 	unsigned char extra_size[2];
 	unsigned char flags[1];
 	unsigned char mtime[4];
 	unsigned char _end[1];
 };

 /*
  * On ARM, padding is added at the end of the struct, so a simple
  * sizeof(struct ...) reports two bytes more than the payload size
  * we're interested in.
  */
 #define ZIP_LOCAL_HEADER_SIZE	offsetof(struct zip_local_header, _end)
 #define ZIP_DATA_DESC_SIZE	offsetof(struct zip_data_desc, _end)
 #define ZIP_DIR_HEADER_SIZE	offsetof(struct zip_dir_header, _end)
 #define ZIP_DIR_TRAILER_SIZE	offsetof(struct zip_dir_trailer, _end)
 #define ZIP_EXTRA_MTIME_SIZE	offsetof(struct zip_extra_mtime, _end)
 #define ZIP_EXTRA_MTIME_PAYLOAD_SIZE \
 	(ZIP_EXTRA_MTIME_SIZE - offsetof(struct zip_extra_mtime, flags))

 static void copy_le16(unsigned char *dest, unsigned int n)
 {
 	dest[0] = 0xff & n;
 	dest[1] = 0xff & (n >> 010);
 }

 static void copy_le32(unsigned char *dest, unsigned int n)
 {
 	dest[0] = 0xff & n;
 	dest[1] = 0xff & (n >> 010);
 	dest[2] = 0xff & (n >> 020);
 	dest[3] = 0xff & (n >> 030);
 }

 static void *zlib_deflate_raw(void *data, unsigned long size,
 			      int compression_level,
 			      unsigned long *compressed_size)
 {
 	git_zstream stream;
 	unsigned long maxsize;
 	void *buffer;
 	int result;

 	memset(&stream, 0, sizeof(stream));
 	git_deflate_init_raw(&stream, compression_level);
 	maxsize = git_deflate_bound(&stream, size);
 	buffer = xmalloc(maxsize);

 	stream.next_in = data;
 	stream.avail_in = size;
 	stream.next_out = buffer;
 	stream.avail_out = maxsize;

 	do {
 		result = git_deflate(&stream, Z_FINISH);
 	} while (result == Z_OK);

 	if (result != Z_STREAM_END) {
 		free(buffer);
 		return NULL;
 	}

 	git_deflate_end(&stream);
 	*compressed_size = stream.total_out;

 	return buffer;
 }

 static void write_zip_data_desc(unsigned long size,
 				unsigned long compressed_size,
 				unsigned long crc)
 {
 	struct zip_data_desc trailer;

 	copy_le32(trailer.magic, 0x08074b50);
 	copy_le32(trailer.crc32, crc);
 	copy_le32(trailer.compressed_size, compressed_size);
 	copy_le32(trailer.size, size);
 	write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
 }

 static void set_zip_dir_data_desc(struct zip_dir_header *header,
 				  unsigned long size,
 				  unsigned long compressed_size,
 				  unsigned long crc)
 {
 	copy_le32(header->crc32, crc);
 	copy_le32(header->compressed_size, compressed_size);
 	copy_le32(header->size, size);
 }

 static void set_zip_header_data_desc(struct zip_local_header *header,
 				     unsigned long size,
 				     unsigned long compressed_size,
 				     unsigned long crc)
 {
 	copy_le32(header->crc32, crc);
 	copy_le32(header->compressed_size, compressed_size);
 	copy_le32(header->size, size);
 }

 static int has_only_ascii(const char *s)
 {
 	for (;;) {
 		int c = *s++;
 		if (c == '\0')
 			return 1;
 		if (!isascii(c))
 			return 0;
 	}
 }

 #define STREAM_BUFFER_SIZE (1024 * 16)

 static int write_zip_entry(struct archiver_args *args,
 			   const unsigned char *sha1,
 			   const char *path, size_t pathlen,
 			   unsigned int mode)
 {
 	struct zip_local_header header;
 	struct zip_dir_header dirent;
 	struct zip_extra_mtime extra;
 	unsigned long attr2;
 	unsigned long compressed_size;
 	unsigned long crc;
 	unsigned long direntsize;
 	int method;
 	unsigned char *out;
 	void *deflated = NULL;
 	void *buffer;
 	struct git_istream *stream = NULL;
 	unsigned long flags = 0;
 	unsigned long size;

 	crc = crc32(0, NULL, 0);

 	if (!has_only_ascii(path)) {
 		if (is_utf8(path))
 			flags |= ZIP_UTF8;
 		else
 			warning("Path is not valid UTF-8: %s", path);
 	}

 	if (pathlen > 0xffff) {
 		return error("path too long (%d chars, SHA1: %s): %s",
 				(int)pathlen, sha1_to_hex(sha1), path);
 	}

 	if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 		method = 0;
 		attr2 = 16;
 		out = NULL;
 		size = 0;
 		compressed_size = 0;
 		buffer = NULL;
 		size = 0;
 	} else if (S_ISREG(mode) || S_ISLNK(mode)) {
 		enum object_type type = sha1_object_info(sha1, &size);

 		method = 0;
 		attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
 			(mode & 0111) ? ((mode) << 16) : 0;
 		if (S_ISREG(mode) && args->compression_level != 0 && size > 0)
 			method = 8;

 		if (S_ISREG(mode) && type == OBJ_BLOB && !args->convert &&
 		    size > big_file_threshold) {
 			stream = open_istream(sha1, &type, &size, NULL);
 			if (!stream)
 				return error("cannot stream blob %s",
 					     sha1_to_hex(sha1));
 			flags |= ZIP_STREAM;
 			out = buffer = NULL;
 		} else {
 			buffer = sha1_file_to_archive(args, path, sha1, mode,
 						      &type, &size);
 			if (!buffer)
 				return error("cannot read %s",
 					     sha1_to_hex(sha1));
 			crc = crc32(crc, buffer, size);
 			out = buffer;
 		}
 		compressed_size = (method == 0) ? size : 0;
 	} else {
 		return error("unsupported file mode: 0%o (SHA1: %s)", mode,
 				sha1_to_hex(sha1));
 	}

 	if (buffer && method == 8) {
 		out = deflated = zlib_deflate_raw(buffer, size,
 						  args->compression_level,
 						  &compressed_size);
 		if (!out || compressed_size >= size) {
 			out = buffer;
 			method = 0;
 			compressed_size = size;
 		}
 	}

 	copy_le16(extra.magic, 0x5455);
 	copy_le16(extra.extra_size, ZIP_EXTRA_MTIME_PAYLOAD_SIZE);
 	extra.flags[0] = 1;	/* just mtime */
 	copy_le32(extra.mtime, args->time);

 	/* make sure we have enough free space in the dictionary */
 	direntsize = ZIP_DIR_HEADER_SIZE + pathlen + ZIP_EXTRA_MTIME_SIZE;
 	while (zip_dir_size < zip_dir_offset + direntsize) {
 		zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
 		zip_dir = xrealloc(zip_dir, zip_dir_size);
 	}

 	copy_le32(dirent.magic, 0x02014b50);
 	copy_le16(dirent.creator_version,
 		S_ISLNK(mode) || (S_ISREG(mode) && (mode & 0111)) ? 0x0317 : 0);
 	copy_le16(dirent.version, 10);
 	copy_le16(dirent.flags, flags);
 	copy_le16(dirent.compression_method, method);
 	copy_le16(dirent.mtime, zip_time);
 	copy_le16(dirent.mdate, zip_date);
 	set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
 	copy_le16(dirent.filename_length, pathlen);
 	copy_le16(dirent.extra_length, ZIP_EXTRA_MTIME_SIZE);
 	copy_le16(dirent.comment_length, 0);
 	copy_le16(dirent.disk, 0);
 	copy_le16(dirent.attr1, 0);
 	copy_le32(dirent.attr2, attr2);
 	copy_le32(dirent.offset, zip_offset);

 	copy_le32(header.magic, 0x04034b50);
 	copy_le16(header.version, 10);
 	copy_le16(header.flags, flags);
 	copy_le16(header.compression_method, method);
 	copy_le16(header.mtime, zip_time);
 	copy_le16(header.mdate, zip_date);
 	set_zip_header_data_desc(&header, size, compressed_size, crc);
 	copy_le16(header.filename_length, pathlen);
 	copy_le16(header.extra_length, ZIP_EXTRA_MTIME_SIZE);
 	write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 	zip_offset += ZIP_LOCAL_HEADER_SIZE;
 	write_or_die(1, path, pathlen);
 	zip_offset += pathlen;
 	write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);
 	zip_offset += ZIP_EXTRA_MTIME_SIZE;
 	if (stream && method == 0) {
 		unsigned char buf[STREAM_BUFFER_SIZE];
 		ssize_t readlen;

 		for (;;) {
 			readlen = read_istream(stream, buf, sizeof(buf));
 			if (readlen <= 0)
 				break;
 			crc = crc32(crc, buf, readlen);
 			write_or_die(1, buf, readlen);
 		}
 		close_istream(stream);
 		if (readlen)
 			return readlen;

 		compressed_size = size;
 		zip_offset += compressed_size;

 		write_zip_data_desc(size, compressed_size, crc);
 		zip_offset += ZIP_DATA_DESC_SIZE;

 		set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
 	} else if (stream && method == 8) {
 		unsigned char buf[STREAM_BUFFER_SIZE];
 		ssize_t readlen;
 		git_zstream zstream;
 		int result;
 		size_t out_len;
 		unsigned char compressed[STREAM_BUFFER_SIZE * 2];

 		memset(&zstream, 0, sizeof(zstream));
 		git_deflate_init_raw(&zstream, args->compression_level);

 		compressed_size = 0;
 		zstream.next_out = compressed;
 		zstream.avail_out = sizeof(compressed);

 		for (;;) {
 			readlen = read_istream(stream, buf, sizeof(buf));
 			if (readlen <= 0)
 				break;
 			crc = crc32(crc, buf, readlen);

 			zstream.next_in = buf;
 			zstream.avail_in = readlen;
 			result = git_deflate(&zstream, 0);
 			if (result != Z_OK)
 				die("deflate error (%d)", result);
 			out_len = zstream.next_out - compressed;

 			if (out_len > 0) {
 				write_or_die(1, compressed, out_len);
 				compressed_size += out_len;
 				zstream.next_out = compressed;
 				zstream.avail_out = sizeof(compressed);
 			}

 		}
 		close_istream(stream);
 		if (readlen)
 			return readlen;

 		zstream.next_in = buf;
 		zstream.avail_in = 0;
 		result = git_deflate(&zstream, Z_FINISH);
 		if (result != Z_STREAM_END)
 			die("deflate error (%d)", result);

 		git_deflate_end(&zstream);
 		out_len = zstream.next_out - compressed;
 		write_or_die(1, compressed, out_len);
 		compressed_size += out_len;
 		zip_offset += compressed_size;

 		write_zip_data_desc(size, compressed_size, crc);
 		zip_offset += ZIP_DATA_DESC_SIZE;

 		set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
 	} else if (compressed_size > 0) {
 		write_or_die(1, out, compressed_size);
 		zip_offset += compressed_size;
 	}

 	free(deflated);
 	free(buffer);

 	memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
 	zip_dir_offset += ZIP_DIR_HEADER_SIZE;
 	memcpy(zip_dir + zip_dir_offset, path, pathlen);
 	zip_dir_offset += pathlen;
 	memcpy(zip_dir + zip_dir_offset, &extra, ZIP_EXTRA_MTIME_SIZE);
 	zip_dir_offset += ZIP_EXTRA_MTIME_SIZE;
 	zip_dir_entries++;

 	return 0;
 }

 static void write_zip_trailer(const unsigned char *sha1)
 {
 	struct zip_dir_trailer trailer;

 	copy_le32(trailer.magic, 0x06054b50);
 	copy_le16(trailer.disk, 0);
 	copy_le16(trailer.directory_start_disk, 0);
 	copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
 	copy_le16(trailer.entries, zip_dir_entries);
 	copy_le32(trailer.size, zip_dir_offset);
 	copy_le32(trailer.offset, zip_offset);
 	copy_le16(trailer.comment_length, sha1 ? 40 : 0);

 	write_or_die(1, zip_dir, zip_dir_offset);
 	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 	if (sha1)
 		write_or_die(1, sha1_to_hex(sha1), 40);
 }

 static void dos_time(time_t *time, int *dos_date, int *dos_time)
 {
 	struct tm *t = localtime(time);

 	*dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
 	            (t->tm_year + 1900 - 1980) * 512;
 	*dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
 }

 static int write_zip_archive(const struct archiver *ar,
 			     struct archiver_args *args)
 {
 	int err;

 	dos_time(&args->time, &zip_date, &zip_time);

 	zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
 	zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;

 	err = write_archive_entries(args, write_zip_entry);
 	if (!err)
 		write_zip_trailer(args->commit_sha1);

 	free(zip_dir);

 	return err;
 }

 static struct archiver zip_archiver = {
 	"zip",
 	write_zip_archive,
 	ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE
 };

 void init_zip_archiver(void)
 {
 	register_archiver(&zip_archiver);
 }
	/*
	* Copyright (c) 2006 Rene Scharfe
	*/
	#include "cache.h"
	#include "archive.h"
	#include "streaming.h"
	#include "utf8.h"

	static int zip_date;
	static int zip_time;

	static unsigned char *zip_dir;
	static unsigned int zip_dir_size;

	static unsigned int zip_offset;
	static unsigned int zip_dir_offset;
	static unsigned int zip_dir_entries;

	#define ZIP_DIRECTORY_MIN_SIZE (1024 * 1024)
	#define ZIP_STREAM (1 << 3)
	#define ZIP_UTF8 (1 << 11)

	struct zip_local_header {
	unsigned char magic[4];
	unsigned char version[2];
	unsigned char flags[2];
	unsigned char compression_method[2];
	unsigned char mtime[2];
	unsigned char mdate[2];
	unsigned char crc32[4];
	unsigned char compressed_size[4];
	unsigned char size[4];
	unsigned char filename_length[2];
	unsigned char extra_length[2];
	unsigned char _end[1];
	};

	struct zip_data_desc {
	unsigned char magic[4];
	unsigned char crc32[4];
	unsigned char compressed_size[4];
	unsigned char size[4];
	unsigned char _end[1];
	};

	struct zip_dir_header {
	unsigned char magic[4];
	unsigned char creator_version[2];
	unsigned char version[2];
	unsigned char flags[2];
	unsigned char compression_method[2];
	unsigned char mtime[2];
	unsigned char mdate[2];
	unsigned char crc32[4];
	unsigned char compressed_size[4];
	unsigned char size[4];
	unsigned char filename_length[2];
	unsigned char extra_length[2];
	unsigned char comment_length[2];
	unsigned char disk[2];
	unsigned char attr1[2];
	unsigned char attr2[4];
	unsigned char offset[4];
	unsigned char _end[1];
	};

	struct zip_dir_trailer {
	unsigned char magic[4];
	unsigned char disk[2];
	unsigned char directory_start_disk[2];
	unsigned char entries_on_this_disk[2];
	unsigned char entries[2];
	unsigned char size[4];
	unsigned char offset[4];
	unsigned char comment_length[2];
	unsigned char _end[1];
	};

	struct zip_extra_mtime {
	unsigned char magic[2];
	unsigned char extra_size[2];
	unsigned char flags[1];
	unsigned char mtime[4];
	unsigned char _end[1];
	};

	/*
	* On ARM, padding is added at the end of the struct, so a simple
	* sizeof(struct ...) reports two bytes more than the payload size
	* we're interested in.
	*/
	#define ZIP_LOCAL_HEADER_SIZE offsetof(struct zip_local_header, _end)
	#define ZIP_DATA_DESC_SIZE offsetof(struct zip_data_desc, _end)
	#define ZIP_DIR_HEADER_SIZE offsetof(struct zip_dir_header, _end)
	#define ZIP_DIR_TRAILER_SIZE offsetof(struct zip_dir_trailer, _end)
	#define ZIP_EXTRA_MTIME_SIZE offsetof(struct zip_extra_mtime, _end)
	#define ZIP_EXTRA_MTIME_PAYLOAD_SIZE \
	(ZIP_EXTRA_MTIME_SIZE - offsetof(struct zip_extra_mtime, flags))

	static void copy_le16(unsigned char *dest, unsigned int n)
	{
	dest[0] = 0xff & n;
	dest[1] = 0xff & (n >> 010);
	}

	static void copy_le32(unsigned char *dest, unsigned int n)
	{
	dest[0] = 0xff & n;
	dest[1] = 0xff & (n >> 010);
	dest[2] = 0xff & (n >> 020);
	dest[3] = 0xff & (n >> 030);
	}

	static void zlib_deflate_raw(void data, unsigned long size,
	int compression_level,
	unsigned long *compressed_size)
	{
	git_zstream stream;
	unsigned long maxsize;
	void *buffer;
	int result;

	memset(&stream, 0, sizeof(stream));
	git_deflate_init_raw(&stream, compression_level);
	maxsize = git_deflate_bound(&stream, size);
	buffer = xmalloc(maxsize);

	stream.next_in = data;
	stream.avail_in = size;
	stream.next_out = buffer;
	stream.avail_out = maxsize;

	do {
	result = git_deflate(&stream, Z_FINISH);
	} while (result == Z_OK);

	if (result != Z_STREAM_END) {
	free(buffer);
	return NULL;
	}

	git_deflate_end(&stream);
	*compressed_size = stream.total_out;

	return buffer;
	}

	static void write_zip_data_desc(unsigned long size,
	unsigned long compressed_size,
	unsigned long crc)
	{
	struct zip_data_desc trailer;

	copy_le32(trailer.magic, 0x08074b50);
	copy_le32(trailer.crc32, crc);
	copy_le32(trailer.compressed_size, compressed_size);
	copy_le32(trailer.size, size);
	write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
	}

	static void set_zip_dir_data_desc(struct zip_dir_header *header,
	unsigned long size,
	unsigned long compressed_size,
	unsigned long crc)
	{
	copy_le32(header->crc32, crc);
	copy_le32(header->compressed_size, compressed_size);
	copy_le32(header->size, size);
	}

	static void set_zip_header_data_desc(struct zip_local_header *header,
	unsigned long size,
	unsigned long compressed_size,
	unsigned long crc)
	{
	copy_le32(header->crc32, crc);
	copy_le32(header->compressed_size, compressed_size);
	copy_le32(header->size, size);
	}

	static int has_only_ascii(const char *s)
	{
	for (;;) {
	int c = *s++;
	if (c == '\0')
	return 1;
	if (!isascii(c))
	return 0;
	}
	}

	#define STREAM_BUFFER_SIZE (1024 * 16)

	static int write_zip_entry(struct archiver_args *args,
	const unsigned char *sha1,
	const char *path, size_t pathlen,
	unsigned int mode)
	{
	struct zip_local_header header;
	struct zip_dir_header dirent;
	struct zip_extra_mtime extra;
	unsigned long attr2;
	unsigned long compressed_size;
	unsigned long crc;
	unsigned long direntsize;
	int method;
	unsigned char *out;
	void *deflated = NULL;
	void *buffer;
	struct git_istream *stream = NULL;
	unsigned long flags = 0;
	unsigned long size;

	crc = crc32(0, NULL, 0);

	if (!has_only_ascii(path)) {
	if (is_utf8(path))
	flags \|= ZIP_UTF8;
	else
	warning("Path is not valid UTF-8: %s", path);
	}

	if (pathlen > 0xffff) {
	return error("path too long (%d chars, SHA1: %s): %s",
	(int)pathlen, sha1_to_hex(sha1), path);
	}

	if (S_ISDIR(mode) \|\| S_ISGITLINK(mode)) {
	method = 0;
	attr2 = 16;
	out = NULL;
	size = 0;
	compressed_size = 0;
	buffer = NULL;
	size = 0;
	} else if (S_ISREG(mode) \|\| S_ISLNK(mode)) {
	enum object_type type = sha1_object_info(sha1, &size);

	method = 0;
	attr2 = S_ISLNK(mode) ? ((mode \| 0777) << 16) :
	(mode & 0111) ? ((mode) << 16) : 0;
	if (S_ISREG(mode) && args->compression_level != 0 && size > 0)
	method = 8;

	if (S_ISREG(mode) && type == OBJ_BLOB && !args->convert &&
	size > big_file_threshold) {
	stream = open_istream(sha1, &type, &size, NULL);
	if (!stream)
	return error("cannot stream blob %s",
	sha1_to_hex(sha1));
	flags \|= ZIP_STREAM;
	out = buffer = NULL;
	} else {
	buffer = sha1_file_to_archive(args, path, sha1, mode,
	&type, &size);
	if (!buffer)
	return error("cannot read %s",
	sha1_to_hex(sha1));
	crc = crc32(crc, buffer, size);
	out = buffer;
	}
	compressed_size = (method == 0) ? size : 0;
	} else {
	return error("unsupported file mode: 0%o (SHA1: %s)", mode,
	sha1_to_hex(sha1));
	}

	if (buffer && method == 8) {
	out = deflated = zlib_deflate_raw(buffer, size,
	args->compression_level,
	&compressed_size);
	if (!out \|\| compressed_size >= size) {
	out = buffer;
	method = 0;
	compressed_size = size;
	}
	}

	copy_le16(extra.magic, 0x5455);
	copy_le16(extra.extra_size, ZIP_EXTRA_MTIME_PAYLOAD_SIZE);
	extra.flags[0] = 1; /* just mtime */
	copy_le32(extra.mtime, args->time);

	/* make sure we have enough free space in the dictionary */
	direntsize = ZIP_DIR_HEADER_SIZE + pathlen + ZIP_EXTRA_MTIME_SIZE;
	while (zip_dir_size < zip_dir_offset + direntsize) {
	zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
	zip_dir = xrealloc(zip_dir, zip_dir_size);
	}

	copy_le32(dirent.magic, 0x02014b50);
	copy_le16(dirent.creator_version,
	S_ISLNK(mode) \|\| (S_ISREG(mode) && (mode & 0111)) ? 0x0317 : 0);
	copy_le16(dirent.version, 10);
	copy_le16(dirent.flags, flags);
	copy_le16(dirent.compression_method, method);
	copy_le16(dirent.mtime, zip_time);
	copy_le16(dirent.mdate, zip_date);
	set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
	copy_le16(dirent.filename_length, pathlen);
	copy_le16(dirent.extra_length, ZIP_EXTRA_MTIME_SIZE);
	copy_le16(dirent.comment_length, 0);
	copy_le16(dirent.disk, 0);
	copy_le16(dirent.attr1, 0);
	copy_le32(dirent.attr2, attr2);
	copy_le32(dirent.offset, zip_offset);

	copy_le32(header.magic, 0x04034b50);
	copy_le16(header.version, 10);
	copy_le16(header.flags, flags);
	copy_le16(header.compression_method, method);
	copy_le16(header.mtime, zip_time);
	copy_le16(header.mdate, zip_date);
	set_zip_header_data_desc(&header, size, compressed_size, crc);
	copy_le16(header.filename_length, pathlen);
	copy_le16(header.extra_length, ZIP_EXTRA_MTIME_SIZE);
	write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
	zip_offset += ZIP_LOCAL_HEADER_SIZE;
	write_or_die(1, path, pathlen);
	zip_offset += pathlen;
	write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);
	zip_offset += ZIP_EXTRA_MTIME_SIZE;
	if (stream && method == 0) {
	unsigned char buf[STREAM_BUFFER_SIZE];
	ssize_t readlen;

	for (;;) {
	readlen = read_istream(stream, buf, sizeof(buf));
	if (readlen <= 0)
	break;
	crc = crc32(crc, buf, readlen);
	write_or_die(1, buf, readlen);
	}
	close_istream(stream);
	if (readlen)
	return readlen;

	compressed_size = size;
	zip_offset += compressed_size;

	write_zip_data_desc(size, compressed_size, crc);
	zip_offset += ZIP_DATA_DESC_SIZE;

	set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
	} else if (stream && method == 8) {
	unsigned char buf[STREAM_BUFFER_SIZE];
	ssize_t readlen;
	git_zstream zstream;
	int result;
	size_t out_len;
	unsigned char compressed[STREAM_BUFFER_SIZE * 2];

	memset(&zstream, 0, sizeof(zstream));
	git_deflate_init_raw(&zstream, args->compression_level);

	compressed_size = 0;
	zstream.next_out = compressed;
	zstream.avail_out = sizeof(compressed);

	for (;;) {
	readlen = read_istream(stream, buf, sizeof(buf));
	if (readlen <= 0)
	break;
	crc = crc32(crc, buf, readlen);

	zstream.next_in = buf;
	zstream.avail_in = readlen;
	result = git_deflate(&zstream, 0);
	if (result != Z_OK)
	die("deflate error (%d)", result);
	out_len = zstream.next_out - compressed;

	if (out_len > 0) {
	write_or_die(1, compressed, out_len);
	compressed_size += out_len;
	zstream.next_out = compressed;
	zstream.avail_out = sizeof(compressed);
	}

	}
	close_istream(stream);
	if (readlen)
	return readlen;

	zstream.next_in = buf;
	zstream.avail_in = 0;
	result = git_deflate(&zstream, Z_FINISH);
	if (result != Z_STREAM_END)
	die("deflate error (%d)", result);

	git_deflate_end(&zstream);
	out_len = zstream.next_out - compressed;
	write_or_die(1, compressed, out_len);
	compressed_size += out_len;
	zip_offset += compressed_size;

	write_zip_data_desc(size, compressed_size, crc);
	zip_offset += ZIP_DATA_DESC_SIZE;

	set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
	} else if (compressed_size > 0) {
	write_or_die(1, out, compressed_size);
	zip_offset += compressed_size;
	}

	free(deflated);
	free(buffer);

	memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
	zip_dir_offset += ZIP_DIR_HEADER_SIZE;
	memcpy(zip_dir + zip_dir_offset, path, pathlen);
	zip_dir_offset += pathlen;
	memcpy(zip_dir + zip_dir_offset, &extra, ZIP_EXTRA_MTIME_SIZE);
	zip_dir_offset += ZIP_EXTRA_MTIME_SIZE;
	zip_dir_entries++;

	return 0;
	}

	static void write_zip_trailer(const unsigned char *sha1)
	{
	struct zip_dir_trailer trailer;

	copy_le32(trailer.magic, 0x06054b50);
	copy_le16(trailer.disk, 0);
	copy_le16(trailer.directory_start_disk, 0);
	copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
	copy_le16(trailer.entries, zip_dir_entries);
	copy_le32(trailer.size, zip_dir_offset);
	copy_le32(trailer.offset, zip_offset);
	copy_le16(trailer.comment_length, sha1 ? 40 : 0);

	write_or_die(1, zip_dir, zip_dir_offset);
	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
	if (sha1)
	write_or_die(1, sha1_to_hex(sha1), 40);
	}

	static void dos_time(time_t time, int dos_date, int *dos_time)
	{
	struct tm *t = localtime(time);

	dos_date = t->tm_mday + (t->tm_mon + 1) 32 +
	(t->tm_year + 1900 - 1980) * 512;
	dos_time = t->tm_sec / 2 + t->tm_min 32 + t->tm_hour * 2048;
	}

	static int write_zip_archive(const struct archiver *ar,
	struct archiver_args *args)
	{
	int err;

	dos_time(&args->time, &zip_date, &zip_time);

	zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
	zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;

	err = write_archive_entries(args, write_zip_entry);
	if (!err)
	write_zip_trailer(args->commit_sha1);

	free(zip_dir);

	return err;
	}

	static struct archiver zip_archiver = {
	"zip",
	write_zip_archive,
	ARCHIVER_WANT_COMPRESSION_LEVELS\|ARCHIVER_REMOTE
	};

	void init_zip_archiver(void)
	{
	register_archiver(&zip_archiver);
	}