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[PATCH v3 2/5] archive-zip: use strbuf for ZIP directory

From
René Scharfe <l.s.r@web.de>
Date
Apr 24, 2017, 17:30 UTC
Message-ID
<949f19e6-0414-9abc-9754-064d7e58c169@web.de>
In-Reply-To
<85f2b6d1-107b-0624-af82-92446f28269e@web.de>

Keep the ZIP central director, which is written after all archive entries, in a strbuf instead of a custom-managed buffer. It contains binary data, so we can't (and don't want to) use the full range of strbuf functions and we don't need the terminating NUL, but the result is shorter and simpler code.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
---
 archive-zip.c | 36 +++++++++++-------------------------
 1 file changed, 11 insertions(+), 25 deletions(-)
diff --git a/archive-zip.c b/archive-zip.c
index b429a8d974..a6fac59602 100644
--- a/archive-zip.c
+++ b/archive-zip.c
@@ -11,16 +11,14 @@
 static int zip_date;
 static int zip_time;
 
-static unsigned char *zip_dir;
-static unsigned int zip_dir_size;
+/* We only care about the "buf" part here. */
+static struct strbuf zip_dir;
 
 static unsigned int zip_offset;
-static unsigned int zip_dir_offset;
 static uint64_t zip_dir_entries;
 
 static unsigned int max_creator_version;
 
-#define ZIP_DIRECTORY_MIN_SIZE	(1024 * 1024)
 #define ZIP_STREAM	(1 <<  3)
 #define ZIP_UTF8	(1 << 11)
 
@@ -268,7 +266,6 @@ static int write_zip_entry(struct archiver_args *args,
 	unsigned long attr2;
 	unsigned long compressed_size;
 	unsigned long crc;
-	unsigned long direntsize;
 	int method;
 	unsigned char *out;
 	void *deflated = NULL;
@@ -356,13 +353,6 @@ static int write_zip_entry(struct archiver_args *args,
 	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, creator_version);
 	copy_le16(dirent.version, 10);
@@ -486,12 +476,9 @@ static int write_zip_entry(struct archiver_args *args,
 
 	copy_le16(dirent.attr1, !is_binary);
 
-	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;
+	strbuf_add(&zip_dir, &dirent, ZIP_DIR_HEADER_SIZE);
+	strbuf_add(&zip_dir, path, pathlen);
+	strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);
 	zip_dir_entries++;
 
 	return 0;
@@ -510,12 +497,12 @@ static void write_zip64_trailer(void)
 	copy_le32(trailer64.directory_start_disk, 0);
 	copy_le64(trailer64.entries_on_this_disk, zip_dir_entries);
 	copy_le64(trailer64.entries, zip_dir_entries);
-	copy_le64(trailer64.size, zip_dir_offset);
+	copy_le64(trailer64.size, zip_dir.len);
 	copy_le64(trailer64.offset, zip_offset);
 
 	copy_le32(locator64.magic, 0x07064b50);
 	copy_le32(locator64.disk, 0);
-	copy_le64(locator64.offset, zip_offset + zip_dir_offset);
+	copy_le64(locator64.offset, zip_offset + zip_dir.len);
 	copy_le32(locator64.number_of_disks, 1);
 
 	write_or_die(1, &trailer64, ZIP64_DIR_TRAILER_SIZE);
@@ -533,11 +520,11 @@ static void write_zip_trailer(const unsigned char *sha1)
 	copy_le16_clamp(trailer.entries_on_this_disk, zip_dir_entries,
 			&clamped);
 	copy_le16_clamp(trailer.entries, zip_dir_entries, &clamped);
-	copy_le32(trailer.size, zip_dir_offset);
+	copy_le32(trailer.size, zip_dir.len);
 	copy_le32(trailer.offset, zip_offset);
 	copy_le16(trailer.comment_length, sha1 ? GIT_SHA1_HEXSZ : 0);
 
-	write_or_die(1, zip_dir, zip_dir_offset);
+	write_or_die(1, zip_dir.buf, zip_dir.len);
 	if (clamped)
 		write_zip64_trailer();
 	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
@@ -568,14 +555,13 @@ static int write_zip_archive(const struct archiver *ar,
 
 	dos_time(&args->time, &zip_date, &zip_time);
 
-	zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
-	zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
+	strbuf_init(&zip_dir, 0);
 
 	err = write_archive_entries(args, write_zip_entry);
 	if (!err)
 		write_zip_trailer(args->commit_sha1);
 
-	free(zip_dir);
+	strbuf_release(&zip_dir);
 
 	return err;
 }
-- 
2.12.2
Previous: René ScharfeNext: Junio C Hamano
Message 12 of 44 in “Git archive doesn't fully support zip64”
  1. Keith GoldfarbApr 21, 2017
  2. archive-zip: Add zip64 headers when file size is too large for 32 bitsPeter Krefting, Apr 22, 2017
  3. Johannes SixtApr 22, 2017
  4. archive-zip: Add zip64 headers when file size is too large for 32 bitsPeter Krefting, Apr 22, 2017
  5. Johannes SixtApr 23, 2017
  6. Peter KreftingApr 23, 2017
  7. Johannes SixtApr 23, 2017
  8. Peter KreftingApr 24, 2017
  9. René ScharfeApr 24, 2017
  10. 0/5 archive-zip: support files and archives bigger than 4GBRené Scharfe, Apr 24, 2017
  11. 1/5 archive-zip: add tests for big ZIP archivesRené Scharfe, Apr 24, 2017
  12. 2/5 archive-zip: use strbuf for ZIP directoryRené Scharfe, Apr 24, 2017
  13. Junio C HamanoApr 25, 2017
  14. René ScharfeApr 25, 2017
  15. 3/5 archive-zip: write ZIP dir entry directly to strbufRené Scharfe, Apr 24, 2017
  16. 4/5 archive-zip: support archives bigger than 4GBRené Scharfe, Apr 24, 2017
  17. Peter KreftingApr 24, 2017
  18. René ScharfeApr 24, 2017
  19. René ScharfeApr 24, 2017
  20. Johannes SixtApr 24, 2017
  21. René ScharfeApr 24, 2017
  22. Peter KreftingApr 25, 2017
  23. René ScharfeApr 25, 2017
  24. Peter KreftingApr 26, 2017
  25. René ScharfeApr 26, 2017
  26. Peter KreftingApr 27, 2017
  27. René ScharfeApr 27, 2017
  28. Peter KreftingApr 28, 2017
  29. 5/5 archive-zip: support files bigger than 4GBRené Scharfe, Apr 24, 2017
  30. Keith GoldfarbApr 24, 2017
  31. Junio C HamanoApr 25, 2017
  32. René ScharfeApr 25, 2017
  33. Torsten BögershausenApr 29, 2017
  34. René ScharfeApr 29, 2017
  35. Torsten BögershausenApr 30, 2017
  36. René ScharfeApr 30, 2017
  37. Torsten BögershausenApr 30, 2017
  38. Johannes SixtApr 30, 2017
  39. René ScharfeApr 30, 2017
  40. Junio C HamanoApr 30, 2017
  41. René ScharfeMay 1, 2017
  42. René ScharfeApr 23, 2017
  43. Peter KreftingApr 23, 2017
  44. Johannes SixtApr 23, 2017

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