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author | kientzle <kientzle@FreeBSD.org> | 2005-02-12 23:00:31 +0000 |
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committer | kientzle <kientzle@FreeBSD.org> | 2005-02-12 23:00:31 +0000 |
commit | 51b8ea9c30e4fd636efc24f54fa5c846d03c4641 (patch) | |
tree | e55d7536a65a5e1887dba9cb44dabd4ff2cf13b8 /lib/libarchive/archive_read_support_format_zip.c | |
parent | 31107ff9be526b7216a47437a397dbc4ab9cdbce (diff) | |
download | FreeBSD-src-51b8ea9c30e4fd636efc24f54fa5c846d03c4641.zip FreeBSD-src-51b8ea9c30e4fd636efc24f54fa5c846d03c4641.tar.gz |
Performance optimization, code clarification, and bug workaround.
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.
Diffstat (limited to 'lib/libarchive/archive_read_support_format_zip.c')
-rw-r--r-- | lib/libarchive/archive_read_support_format_zip.c | 64 |
1 files changed, 36 insertions, 28 deletions
diff --git a/lib/libarchive/archive_read_support_format_zip.c b/lib/libarchive/archive_read_support_format_zip.c index 081acaa..072c0cd 100644 --- a/lib/libarchive/archive_read_support_format_zip.c +++ b/lib/libarchive/archive_read_support_format_zip.c @@ -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); } |