d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Performance optimization, code clarification, and bug workaround.

Browse Source 
When reading the bodies of Zip archive entries, request a minimum of 1
byte, rather than a minimum of the full entry size.  This is faster
(since it does not force the decompression layer to combine reads) and
works around a bug in the "none" decompression handler (which I'm
testing a separate fix for now).  I've also renamed "bytes_read" to
"bytes_avail" in several places to more accurately reflect that the
value returned from (a->compression_read_ahead) is the number of bytes
available, not necessarily the number of bytes requested.
This commit is contained in:
Tim Kientzle 2005-02-12 23:00:31 +00:00
parent e3485a974c
commit 0a4b2ab59c
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=141772
1 changed files with 36 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
lib/libarchive/archive_read_support_format_zip.c
View File

@ -31,6 +31,7 @@ __FBSDID("$FreeBSD$");
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#endif
@ -336,7 +337,7 @@ zip_read_data_none(struct archive *a, const void **buff,
size_t *size, off_t *offset)
{
struct zip *zip;
ssize_t bytes_read;
ssize_t bytes_avail;
zip = *(a->pformat_data);
@ -346,18 +347,22 @@ zip_read_data_none(struct archive *a, const void **buff,
*offset = zip->entry_offset;
return (ARCHIVE_EOF);
}
bytes_read = (a->compression_read_ahead)(a, buff,
zip->entry_bytes_remaining);
if (bytes_read <= 0) {
/*
* Note: '1' here is a performance optimization.
* Recall that the decompression layer returns a count of
* available bytes; asking for more than that forces the
* decompressor to combine reads by copying data.
*/
bytes_avail = (a->compression_read_ahead)(a, buff, 1);
if (bytes_avail <= 0) {
archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
"Truncated ZIP file data");
return (ARCHIVE_FATAL);
}
if (bytes_read > zip->entry_bytes_remaining)
bytes_read = zip->entry_bytes_remaining;
(a->compression_read_consume)(a, bytes_read);
*size = bytes_read;
if (bytes_avail > zip->entry_bytes_remaining)
bytes_avail = zip->entry_bytes_remaining;
(a->compression_read_consume)(a, bytes_avail);
*size = bytes_avail;
*offset = zip->entry_offset;
zip->entry_offset += *size;
zip->entry_bytes_remaining -= *size;
@ -370,7 +375,7 @@ zip_read_data_deflate(struct archive *a, const void **buff,
size_t *size, off_t *offset)
{
struct zip *zip;
ssize_t bytes_read;
ssize_t bytes_avail;
const void *compressed_buff;
int r;
@ -399,16 +404,20 @@ zip_read_data_deflate(struct archive *a, const void **buff,
}
}
/* Read the next block of compressed data. */
bytes_read = (a->compression_read_ahead)(a, &compressed_buff,
zip->entry_bytes_remaining);
if (bytes_read <= 0) {
/*
* Note: '1' here is a performance optimization.
* Recall that the decompression layer returns a count of
* available bytes; asking for more than that forces the
* decompressor to combine reads by copying data.
*/
bytes_avail = (a->compression_read_ahead)(a, &compressed_buff, 1);
if (bytes_avail <= 0) {
archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
"Truncated ZIP file body");
return (ARCHIVE_FATAL);
}
if (bytes_read > zip->entry_bytes_remaining)
bytes_read = zip->entry_bytes_remaining;
if (bytes_avail > zip->entry_bytes_remaining)
bytes_avail = zip->entry_bytes_remaining;
/*
* A bug in zlib.h: stream.next_in should be marked 'const'
@ -417,7 +426,7 @@ zip_read_data_deflate(struct archive *a, const void **buff,
* cast to remove 'const'.
*/
zip->stream.next_in = (void *)(uintptr_t)(const void *)compressed_buff;
zip->stream.avail_in = bytes_read;
zip->stream.avail_in = bytes_avail;
zip->stream.total_in = 0;
zip->stream.next_out = zip->uncompressed_buffer;
zip->stream.avail_out = zip->uncompressed_buffer_size;
@ -441,9 +450,9 @@ zip_read_data_deflate(struct archive *a, const void **buff,
}
/* Consume as much as the compressor actually used. */
bytes_read = zip->stream.total_in;
(a->compression_read_consume)(a, bytes_read);
zip->entry_bytes_remaining -= bytes_read;
bytes_avail = zip->stream.total_in;
(a->compression_read_consume)(a, bytes_avail);
zip->entry_bytes_remaining -= bytes_avail;
*offset = zip->entry_offset;
@ -471,7 +480,7 @@ zip_read_data_skip(struct archive *a, const void **buff,
size_t *size, off_t *offset)
{
struct zip *zip;
ssize_t bytes_read;
ssize_t bytes_avail;
zip = *(a->pformat_data);
@ -483,17 +492,16 @@ zip_read_data_skip(struct archive *a, const void **buff,
/* Skip body of entry. */
while (zip->entry_bytes_remaining > 0) {
bytes_read = (a->compression_read_ahead)(a, buff,
zip->entry_bytes_remaining);
if (bytes_read <= 0) {
bytes_avail = (a->compression_read_ahead)(a, buff, 1);
if (bytes_avail <= 0) {
archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
"Truncated ZIP file body");
return (ARCHIVE_FATAL);
}
if (bytes_read > zip->entry_bytes_remaining)
bytes_read = zip->entry_bytes_remaining;
(a->compression_read_consume)(a, bytes_read);
zip->entry_bytes_remaining -= bytes_read;
if (bytes_avail > zip->entry_bytes_remaining)
bytes_avail = zip->entry_bytes_remaining;
(a->compression_read_consume)(a, bytes_avail);
zip->entry_bytes_remaining -= bytes_avail;
}
return (ARCHIVE_OK);
}