cheng/zlib
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Permit stronger flushes after Z_BLOCK flushes.

Browse Source 
The incorporation of the Z_BLOCK flush did not update the rejection
of lower ranked flushes immediately after higher ranked flushes with
no more input data.  This prevented an empty Z_SYNC_FLUSH right after
a Z_BLOCK flush, which would be desired to bring the deflate stream
to a byte boundary conditionally on whether or not it was already at
a byte boundary.  This patch re-ranks Z_BLOCK above Z_NO_FLUSH but
below Z_PARTIAL_FLUSH, allowing stronger empty flushes to follow a
Z_BLOCK flush.
This commit is contained in:
Mark Adler 2011-12-28 23:57:14 -08:00
parent bafcad9028
commit f1ebdd6a9c
1 changed files with 4 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
deflate.c
View File

@ -155,6 +155,9 @@ local const config configuration_table[10] = {
struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
#endif #endif
/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
#define RANK(f) (((f) << 1) - ((f) > 4 ? 9 : 0))
/* =========================================================================== /* ===========================================================================
* Update a hash value with the given input byte * Update a hash value with the given input byte
* IN assertion: all calls to to UPDATE_HASH are made with consecutive * IN assertion: all calls to to UPDATE_HASH are made with consecutive
@ -858,7 +861,7 @@ int ZEXPORT deflate (strm, flush)
* flushes. For repeated and useless calls with Z_FINISH, we keep * flushes. For repeated and useless calls with Z_FINISH, we keep
* returning Z_STREAM_END instead of Z_BUF_ERROR. * returning Z_STREAM_END instead of Z_BUF_ERROR.
*/ */
} else if (strm->avail_in == 0 && flush <= old_flush && } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
flush != Z_FINISH) { flush != Z_FINISH) {
ERR_RETURN(strm, Z_BUF_ERROR); ERR_RETURN(strm, Z_BUF_ERROR);
} }