ca5d86d52
Daniel Edgecumbe
2019-09-05
Subject
gzip: set compression flags correctly as per standard
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
archival/gzip.c+18 -8
| @@ -259,6 +259,7 @@ enum { | |
| #if !ENABLE_FEATURE_GZIP_LEVELS | |
| + | comp_level = 9, |
| max_chain_length = 4096, | |
| /* To speed up deflation, hash chains are never searched beyond this length. | |
| * A higher limit improves compression ratio but degrades the speed. | |
| @@ -334,14 +335,16 @@ struct globals { | |
| #define head (G1.prev + WSIZE) /* hash head (see deflate.c) */ | |
| #if ENABLE_FEATURE_GZIP_LEVELS | |
| + | unsigned comp_level; |
| unsigned max_chain_length; | |
| unsigned max_lazy_match; | |
| unsigned good_match; | |
| unsigned nice_match; | |
| + | #define comp_level (G1.comp_level) |
| #define max_chain_length (G1.max_chain_length) | |
| #define max_lazy_match (G1.max_lazy_match) | |
| - | #define good_match (G1.good_match) |
| - | #define nice_match (G1.nice_match) |
| + | #define good_match (G1.good_match) |
| + | #define nice_match (G1.nice_match) |
| #endif | |
| /* =========================================================================== */ | |
| @@ -1919,7 +1922,7 @@ static void bi_init(void) | |
| /* =========================================================================== | |
| * Initialize the "longest match" routines for a new file | |
| */ | |
| - | static void lm_init(unsigned *flags16p) |
| + | static void lm_init(void) |
| { | |
| unsigned j; | |
| @@ -1927,8 +1930,6 @@ static void lm_init(unsigned *flags16p) | |
| memset(head, 0, HASH_SIZE * sizeof(*head)); | |
| /* prev will be initialized on the fly */ | |
| - | /* speed options for the general purpose bit flag */ |
| - | *flags16p |= 2; /* FAST 4, SLOW 2 */ |
| /* ??? reduce max_chain_length for binary files */ | |
| //G1.strstart = 0; // globals are zeroed in pack_gzip() | |
| @@ -2076,10 +2077,16 @@ static void zip(void) | |
| bi_init(); | |
| ct_init(); | |
| - | deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */ |
| - | lm_init(&deflate_flags); |
| + | lm_init(); |
| - | put_16bit(deflate_flags | 0x300); /* extra flags. OS id = 3 (Unix) */ |
| + | deflate_flags = 0x300; /* extra flags. OS id = 3 (Unix) */ |
| + | #if ENABLE_FEATURE_GZIP_LEVELS |
| + | /* Note that comp_level < 4 do not exist in this version of gzip */ |
| + | if (comp_level == 9) { |
| + | deflate_flags |= 0x02; /* SLOW flag */ |
| + | } |
| + | #endif |
| + | put_16bit(deflate_flags); |
| /* The above 32-bit misaligns outbuf (10 bytes are stored), flush it */ | |
| flush_outbuf_if_32bit_optimized(); | |
| @@ -2224,6 +2231,9 @@ int gzip_main(int argc UNUSED_PARAM, char **argv) | |
| if (opt == 0) | |
| opt = 1 << 5; /* default: 6 */ | |
| opt = ffs(opt >> 4); /* Maps -1..-4 to [0], -5 to [1] ... -9 to [5] */ | |
| + | |
| + | comp_level = opt + 4; |
| + | |
| max_chain_length = 1 << gzip_level_config[opt].chain_shift; | |
| good_match = gzip_level_config[opt].good; | |
| max_lazy_match = gzip_level_config[opt].lazy2 * 2; | |