diff options
| author | Mikhail Zaslonko | 2023-01-26 14:14:22 +0100 |
|---|---|---|
| committer | Andrew Morton | 2023-02-02 22:50:08 -0800 |
| commit | 9a549338260ac6eaa495095d4c237aee09aa5a99 (patch) | |
| tree | 54bd03daeeabc36ca328183de442e19082b11f51 /lib/zlib_dfltcc | |
| parent | 4cc06c9afbb4dbed007f06450127ab745d6dc450 (diff) | |
lib/zlib: implement switching between DFLTCC and software
This commit is based on:
https://github.com/zlib-ng/zlib-ng/commit/fc04275
Link: https://lkml.kernel.org/r/20230126131428.1222214-3-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/zlib_dfltcc')
| -rw-r--r-- | lib/zlib_dfltcc/dfltcc_deflate.c | 38 |
1 files changed, 22 insertions, 16 deletions
diff --git a/lib/zlib_dfltcc/dfltcc_deflate.c b/lib/zlib_dfltcc/dfltcc_deflate.c index 6c946e8532ee..dc85ec890163 100644 --- a/lib/zlib_dfltcc/dfltcc_deflate.c +++ b/lib/zlib_dfltcc/dfltcc_deflate.c @@ -112,30 +112,36 @@ int dfltcc_deflate( int soft_bcc; int no_flush; - if (!dfltcc_can_deflate(strm)) + if (!dfltcc_can_deflate(strm)) { + /* Clear history. */ + if (flush == Z_FULL_FLUSH) + param->hl = 0; return 0; + } again: masked_avail_in = 0; soft_bcc = 0; no_flush = flush == Z_NO_FLUSH; - /* Trailing empty block. Switch to software, except when Continuation Flag - * is set, which means that DFLTCC has buffered some output in the - * parameter block and needs to be called again in order to flush it. + /* No input data. Return, except when Continuation Flag is set, which means + * that DFLTCC has buffered some output in the parameter block and needs to + * be called again in order to flush it. */ - if (flush == Z_FINISH && strm->avail_in == 0 && !param->cf) { - if (param->bcf) { - /* A block is still open, and the hardware does not support closing - * blocks without adding data. Thus, close it manually. - */ + if (strm->avail_in == 0 && !param->cf) { + /* A block is still open, and the hardware does not support closing + * blocks without adding data. Thus, close it manually. + */ + if (!no_flush && param->bcf) { send_eobs(strm, param); param->bcf = 0; } - return 0; - } - - if (strm->avail_in == 0 && !param->cf) { + /* Let one of deflate_* functions write a trailing empty block. */ + if (flush == Z_FINISH) + return 0; + /* Clear history. */ + if (flush == Z_FULL_FLUSH) + param->hl = 0; *result = need_more; return 1; } @@ -189,7 +195,7 @@ again: param->cvt = CVT_ADLER32; if (!no_flush) /* We need to close a block. Always do this in software - when there is - * no input data, the hardware will not nohor BCC. */ + * no input data, the hardware will not hohor BCC. */ soft_bcc = 1; if (flush == Z_FINISH && !param->bcf) /* We are about to open a BFINAL block, set Block Header Final bit @@ -204,8 +210,8 @@ again: param->sbb = (unsigned int)state->bi_valid; if (param->sbb > 0) *strm->next_out = (Byte)state->bi_buf; - if (param->hl) - param->nt = 0; /* Honor history */ + /* Honor history and check value */ + param->nt = 0; param->cv = strm->adler; /* When opening a block, choose a Huffman-Table Type */ |