From 3d4f688a1907c80678d3f0ed4bc4fd9f99b9a63b Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 8 Apr 2018 16:31:02 +0200 Subject: [PATCH] lzop: buffer several 32-bit writes when we start a new compressed block function old new delta lzo_compress 483 531 +48 Signed-off-by: Denys Vlasenko --- archival/lzop.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/archival/lzop.c b/archival/lzop.c index f7b3bc53c..b6a3cca09 100644 --- a/archival/lzop.c +++ b/archival/lzop.c @@ -637,10 +637,8 @@ static NOINLINE int lzo_compress(const header_t *h) int r = 0; /* LZO_E_OK */ uint8_t *const b1 = xzalloc(block_size); uint8_t *const b2 = xzalloc(MAX_COMPRESSED_SIZE(block_size)); - unsigned src_len = 0, dst_len = 0; uint32_t d_adler32 = ADLER32_INIT_VALUE; uint32_t d_crc32 = CRC32_INIT_VALUE; - int l; uint8_t *wrk_mem = NULL; if (h->method == M_LZO1X_1) @@ -651,16 +649,22 @@ static NOINLINE int lzo_compress(const header_t *h) wrk_mem = xzalloc(LZO1X_999_MEM_COMPRESS); for (;;) { + unsigned src_len, dst_len; + int l; + uint32_t wordbuf[6]; + uint32_t *wordptr = wordbuf; + /* read a block */ l = full_read(0, b1, block_size); src_len = (l > 0 ? l : 0); /* write uncompressed block size */ - write32(src_len); - /* exit if last block */ - if (src_len == 0) + if (src_len == 0) { + write32(0); break; + } + *wordptr++ = htonl(src_len); /* compute checksum of uncompressed block */ if (h->flags32 & F_ADLER32_D) @@ -693,30 +697,36 @@ static NOINLINE int lzo_compress(const header_t *h) if (r != 0 /*LZO_E_OK*/ || new_len != src_len) bb_error_msg_and_die("%s: %s", "internal error", "optimization"); } - write32(dst_len); + *wordptr++ = htonl(dst_len); } else { /* data actually expanded => store data uncompressed */ - write32(src_len); + *wordptr++ = htonl(src_len); } /* write checksum of uncompressed block */ if (h->flags32 & F_ADLER32_D) - write32(d_adler32); + *wordptr++ = htonl(d_adler32); if (h->flags32 & F_CRC32_D) - write32(d_crc32); + *wordptr++ = htonl(d_crc32); if (dst_len < src_len) { /* write checksum of compressed block */ if (h->flags32 & F_ADLER32_C) - write32(lzo_adler32(ADLER32_INIT_VALUE, b2, dst_len)); + *wordptr++ = htonl(lzo_adler32(ADLER32_INIT_VALUE, b2, dst_len)); if (h->flags32 & F_CRC32_C) - write32(lzo_crc32(CRC32_INIT_VALUE, b2, dst_len)); + *wordptr++ = htonl(lzo_crc32(CRC32_INIT_VALUE, b2, dst_len)); + } + xwrite(1, wordbuf, ((char*)wordptr) - ((char*)wordbuf)); + if (dst_len < src_len) { /* write compressed block data */ xwrite(1, b2, dst_len); } else { /* write uncompressed block data */ xwrite(1, b1, src_len); } + // /* if full_read() was nevertheless "short", it was EOF */ + // if (src_len < block_size) + // break; } free(wrk_mem); -- 2.25.1