1 /* Lzma86Enc.c -- LZMA + x86 (BCJ) Filter Encoder
2 2009-08-14 : Igor Pavlov : Public domain */
3
4 #include <string.h>
5
6 #include "Lzma86.h"
7
8 #include "Alloc.h"
9 #include "Bra.h"
10 #include "LzmaEnc.h"
11
12 #define SZE_OUT_OVERFLOW SZE_DATA_ERROR
13
SzAlloc(void * p,size_t size)14 static void *SzAlloc(void *p, size_t size) { p = p; return MyAlloc(size); }
SzFree(void * p,void * address)15 static void SzFree(void *p, void *address) { p = p; MyFree(address); }
16
Lzma86_Encode(Byte * dest,size_t * destLen,const Byte * src,size_t srcLen,int level,UInt32 dictSize,int filterMode)17 int Lzma86_Encode(Byte *dest, size_t *destLen, const Byte *src, size_t srcLen,
18 int level, UInt32 dictSize, int filterMode)
19 {
20 ISzAlloc g_Alloc = { SzAlloc, SzFree };
21 size_t outSize2 = *destLen;
22 Byte *filteredStream;
23 Bool useFilter;
24 int mainResult = SZ_ERROR_OUTPUT_EOF;
25 CLzmaEncProps props;
26 LzmaEncProps_Init(&props);
27 props.level = level;
28 props.dictSize = dictSize;
29
30 *destLen = 0;
31 if (outSize2 < LZMA86_HEADER_SIZE)
32 return SZ_ERROR_OUTPUT_EOF;
33
34 {
35 int i;
36 UInt64 t = srcLen;
37 for (i = 0; i < 8; i++, t >>= 8)
38 dest[LZMA86_SIZE_OFFSET + i] = (Byte)t;
39 }
40
41 filteredStream = 0;
42 useFilter = (filterMode != SZ_FILTER_NO);
43 if (useFilter)
44 {
45 if (srcLen != 0)
46 {
47 filteredStream = (Byte *)MyAlloc(srcLen);
48 if (filteredStream == 0)
49 return SZ_ERROR_MEM;
50 memcpy(filteredStream, src, srcLen);
51 }
52 {
53 UInt32 x86State;
54 x86_Convert_Init(x86State);
55 x86_Convert(filteredStream, srcLen, 0, &x86State, 1);
56 }
57 }
58
59 {
60 size_t minSize = 0;
61 Bool bestIsFiltered = False;
62
63 /* passes for SZ_FILTER_AUTO:
64 0 - BCJ + LZMA
65 1 - LZMA
66 2 - BCJ + LZMA agaian, if pass 0 (BCJ + LZMA) is better.
67 */
68 int numPasses = (filterMode == SZ_FILTER_AUTO) ? 3 : 1;
69
70 int i;
71 for (i = 0; i < numPasses; i++)
72 {
73 size_t outSizeProcessed = outSize2 - LZMA86_HEADER_SIZE;
74 size_t outPropsSize = 5;
75 SRes curRes;
76 Bool curModeIsFiltered = (numPasses > 1 && i == numPasses - 1);
77 if (curModeIsFiltered && !bestIsFiltered)
78 break;
79 if (useFilter && i == 0)
80 curModeIsFiltered = True;
81
82 curRes = LzmaEncode(dest + LZMA86_HEADER_SIZE, &outSizeProcessed,
83 curModeIsFiltered ? filteredStream : src, srcLen,
84 &props, dest + 1, &outPropsSize, 0,
85 NULL, &g_Alloc, &g_Alloc);
86
87 if (curRes != SZ_ERROR_OUTPUT_EOF)
88 {
89 if (curRes != SZ_OK)
90 {
91 mainResult = curRes;
92 break;
93 }
94 if (outSizeProcessed <= minSize || mainResult != SZ_OK)
95 {
96 minSize = outSizeProcessed;
97 bestIsFiltered = curModeIsFiltered;
98 mainResult = SZ_OK;
99 }
100 }
101 }
102 dest[0] = (Byte)(bestIsFiltered ? 1 : 0);
103 *destLen = LZMA86_HEADER_SIZE + minSize;
104 }
105 if (useFilter)
106 MyFree(filteredStream);
107 return mainResult;
108 }
109