archive-zip: write ZIP dir entry directly to strbuf

Write all fields of the ZIP directory record for an archive entry in the right order directly into the strbuf instead of taking a detour through a struct. Do that at end, when we have all necessary data like checksum and compressed size. The fields are documented just as well, the code becomes shorter and we save an extra copy. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

René Scharfe committed Apr 24, 2017 at 19:31 UTC 3c78fd808d8ed8848fe09735c7755ddd35cfe83f
1 file changed +27 -54
archive-zip.c
+27 -54
@@ -45,27 +45,6 @@ struct zip_data_desc {
45 unsigned char _end[1];
46 };
47
48 -struct zip_dir_header {
49 - unsigned char magic[4];
50 - unsigned char creator_version[2];
51 - unsigned char version[2];
52 - unsigned char flags[2];
53 - unsigned char compression_method[2];
54 - unsigned char mtime[2];
55 - unsigned char mdate[2];
56 - unsigned char crc32[4];
57 - unsigned char compressed_size[4];
58 - unsigned char size[4];
59 - unsigned char filename_length[2];
60 - unsigned char extra_length[2];
61 - unsigned char comment_length[2];
62 - unsigned char disk[2];
63 - unsigned char attr1[2];
64 - unsigned char attr2[4];
65 - unsigned char offset[4];
66 - unsigned char _end[1];
67 -};
68 -
48 struct zip_dir_trailer {
49 unsigned char magic[4];
50 unsigned char disk[2];
@@ -166,6 +145,15 @@ static void copy_le16_clamp(unsigned char *dest, uint64_t n, int *clamped)
145 copy_le16(dest, clamp_max(n, 0xffff, clamped));
146 }
147
148 +static int strbuf_add_le(struct strbuf *sb, size_t size, uintmax_t n)
149 +{
150 + while (size-- > 0) {
151 + strbuf_addch(sb, n & 0xff);
152 + n >>= 8;
153 + }
154 + return -!!n;
155 +}
156 +
157 static void *zlib_deflate_raw(void *data, unsigned long size,
158 int compression_level,
159 unsigned long *compressed_size)
@@ -212,16 +200,6 @@ static void write_zip_data_desc(unsigned long size,
200 write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
201 }
202
215 -static void set_zip_dir_data_desc(struct zip_dir_header *header,
216 - unsigned long size,
217 - unsigned long compressed_size,
218 - unsigned long crc)
219 -{
220 - copy_le32(header->crc32, crc);
221 - copy_le32(header->compressed_size, compressed_size);
222 - copy_le32(header->size, size);
223 -}
224 -
203 static void set_zip_header_data_desc(struct zip_local_header *header,
204 unsigned long size,
205 unsigned long compressed_size,
@@ -261,7 +239,7 @@ static int write_zip_entry(struct archiver_args *args,
239 unsigned int mode)
240 {
241 struct zip_local_header header;
264 - struct zip_dir_header dirent;
242 + uintmax_t offset = zip_offset;
243 struct zip_extra_mtime extra;
244 unsigned long attr2;
245 unsigned long compressed_size;
@@ -353,21 +331,6 @@ static int write_zip_entry(struct archiver_args *args,
331 extra.flags[0] = 1; /* just mtime */
332 copy_le32(extra.mtime, args->time);
333
356 - copy_le32(dirent.magic, 0x02014b50);
357 - copy_le16(dirent.creator_version, creator_version);
358 - copy_le16(dirent.version, 10);
359 - copy_le16(dirent.flags, flags);
360 - copy_le16(dirent.compression_method, method);
361 - copy_le16(dirent.mtime, zip_time);
362 - copy_le16(dirent.mdate, zip_date);
363 - set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
364 - copy_le16(dirent.filename_length, pathlen);
365 - copy_le16(dirent.extra_length, ZIP_EXTRA_MTIME_SIZE);
366 - copy_le16(dirent.comment_length, 0);
367 - copy_le16(dirent.disk, 0);
368 - copy_le32(dirent.attr2, attr2);
369 - copy_le32(dirent.offset, zip_offset);
370 -
334 copy_le32(header.magic, 0x04034b50);
335 copy_le16(header.version, 10);
336 copy_le16(header.flags, flags);
@@ -406,8 +369,6 @@ static int write_zip_entry(struct archiver_args *args,
369
370 write_zip_data_desc(size, compressed_size, crc);
371 zip_offset += ZIP_DATA_DESC_SIZE;
409 -
410 - set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
372 } else if (stream && method == 8) {
373 unsigned char buf[STREAM_BUFFER_SIZE];
374 ssize_t readlen;
@@ -464,8 +425,6 @@ static int write_zip_entry(struct archiver_args *args,
425
426 write_zip_data_desc(size, compressed_size, crc);
427 zip_offset += ZIP_DATA_DESC_SIZE;
467 -
468 - set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
428 } else if (compressed_size > 0) {
429 write_or_die(1, out, compressed_size);
430 zip_offset += compressed_size;
@@ -474,9 +433,23 @@ static int write_zip_entry(struct archiver_args *args,
433 free(deflated);
434 free(buffer);
435
477 - copy_le16(dirent.attr1, !is_binary);
478 -
479 - strbuf_add(&zip_dir, &dirent, ZIP_DIR_HEADER_SIZE);
436 + strbuf_add_le(&zip_dir, 4, 0x02014b50); /* magic */
437 + strbuf_add_le(&zip_dir, 2, creator_version);
438 + strbuf_add_le(&zip_dir, 2, 10); /* version */
439 + strbuf_add_le(&zip_dir, 2, flags);
440 + strbuf_add_le(&zip_dir, 2, method);
441 + strbuf_add_le(&zip_dir, 2, zip_time);
442 + strbuf_add_le(&zip_dir, 2, zip_date);
443 + strbuf_add_le(&zip_dir, 4, crc);
444 + strbuf_add_le(&zip_dir, 4, compressed_size);
445 + strbuf_add_le(&zip_dir, 4, size);
446 + strbuf_add_le(&zip_dir, 2, pathlen);
447 + strbuf_add_le(&zip_dir, 2, ZIP_EXTRA_MTIME_SIZE);
448 + strbuf_add_le(&zip_dir, 2, 0); /* comment length */
449 + strbuf_add_le(&zip_dir, 2, 0); /* disk */
450 + strbuf_add_le(&zip_dir, 2, !is_binary);
451 + strbuf_add_le(&zip_dir, 4, attr2);
452 + strbuf_add_le(&zip_dir, 4, offset);
453 strbuf_add(&zip_dir, path, pathlen);
454 strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);
455 zip_dir_entries++;