1 // LZ4 streaming API example : ring buffer
2 // Based on sample code from Takayuki Matsuoka
3
4
5 /**************************************
6 * Compiler Options
7 **************************************/
8 #ifdef _MSC_VER /* Visual Studio */
9 # define _CRT_SECURE_NO_WARNINGS // for MSVC
10 # define snprintf sprintf_s
11 #endif
12 #ifdef __GNUC__
13 # pragma GCC diagnostic ignored "-Wmissing-braces" /* GCC bug 53119 : doesn't accept { 0 } as initializer (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119) */
14 #endif
15
16
17 /**************************************
18 * Includes
19 **************************************/
20 #include <stdio.h>
21 #include <stdint.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include "lz4.h"
25
26
27 enum {
28 MESSAGE_MAX_BYTES = 1024,
29 RING_BUFFER_BYTES = 1024 * 8 + MESSAGE_MAX_BYTES,
30 DECODE_RING_BUFFER = RING_BUFFER_BYTES + MESSAGE_MAX_BYTES // Intentionally larger, to test unsynchronized ring buffers
31 };
32
33
write_int32(FILE * fp,int32_t i)34 size_t write_int32(FILE* fp, int32_t i) {
35 return fwrite(&i, sizeof(i), 1, fp);
36 }
37
write_bin(FILE * fp,const void * array,int arrayBytes)38 size_t write_bin(FILE* fp, const void* array, int arrayBytes) {
39 return fwrite(array, 1, arrayBytes, fp);
40 }
41
read_int32(FILE * fp,int32_t * i)42 size_t read_int32(FILE* fp, int32_t* i) {
43 return fread(i, sizeof(*i), 1, fp);
44 }
45
read_bin(FILE * fp,void * array,int arrayBytes)46 size_t read_bin(FILE* fp, void* array, int arrayBytes) {
47 return fread(array, 1, arrayBytes, fp);
48 }
49
50
test_compress(FILE * outFp,FILE * inpFp)51 void test_compress(FILE* outFp, FILE* inpFp)
52 {
53 LZ4_stream_t lz4Stream_body = { 0 };
54 LZ4_stream_t* lz4Stream = &lz4Stream_body;
55
56 static char inpBuf[RING_BUFFER_BYTES];
57 int inpOffset = 0;
58
59 for(;;) {
60 // Read random length ([1,MESSAGE_MAX_BYTES]) data to the ring buffer.
61 char* const inpPtr = &inpBuf[inpOffset];
62 const int randomLength = (rand() % MESSAGE_MAX_BYTES) + 1;
63 const int inpBytes = (int) read_bin(inpFp, inpPtr, randomLength);
64 if (0 == inpBytes) break;
65
66 {
67 char cmpBuf[LZ4_COMPRESSBOUND(MESSAGE_MAX_BYTES)];
68 const int cmpBytes = LZ4_compress_continue(lz4Stream, inpPtr, cmpBuf, inpBytes);
69 if(cmpBytes <= 0) break;
70 write_int32(outFp, cmpBytes);
71 write_bin(outFp, cmpBuf, cmpBytes);
72
73 inpOffset += inpBytes;
74
75 // Wraparound the ringbuffer offset
76 if(inpOffset >= RING_BUFFER_BYTES - MESSAGE_MAX_BYTES) inpOffset = 0;
77 }
78 }
79
80 write_int32(outFp, 0);
81 }
82
83
test_decompress(FILE * outFp,FILE * inpFp)84 void test_decompress(FILE* outFp, FILE* inpFp)
85 {
86 static char decBuf[DECODE_RING_BUFFER];
87 int decOffset = 0;
88 LZ4_streamDecode_t lz4StreamDecode_body = { 0 };
89 LZ4_streamDecode_t* lz4StreamDecode = &lz4StreamDecode_body;
90
91 for(;;) {
92 int cmpBytes = 0;
93 char cmpBuf[LZ4_COMPRESSBOUND(MESSAGE_MAX_BYTES)];
94
95 {
96 const size_t r0 = read_int32(inpFp, &cmpBytes);
97 if(r0 != 1 || cmpBytes <= 0) break;
98
99 const size_t r1 = read_bin(inpFp, cmpBuf, cmpBytes);
100 if(r1 != (size_t) cmpBytes) break;
101 }
102
103 {
104 char* const decPtr = &decBuf[decOffset];
105 const int decBytes = LZ4_decompress_safe_continue(
106 lz4StreamDecode, cmpBuf, decPtr, cmpBytes, MESSAGE_MAX_BYTES);
107 if(decBytes <= 0) break;
108 decOffset += decBytes;
109 write_bin(outFp, decPtr, decBytes);
110
111 // Wraparound the ringbuffer offset
112 if(decOffset >= DECODE_RING_BUFFER - MESSAGE_MAX_BYTES) decOffset = 0;
113 }
114 }
115 }
116
117
compare(FILE * f0,FILE * f1)118 int compare(FILE* f0, FILE* f1)
119 {
120 int result = 0;
121
122 while(0 == result) {
123 char b0[65536];
124 char b1[65536];
125 const size_t r0 = fread(b0, 1, sizeof(b0), f0);
126 const size_t r1 = fread(b1, 1, sizeof(b1), f1);
127
128 result = (int) r0 - (int) r1;
129
130 if(0 == r0 || 0 == r1) {
131 break;
132 }
133 if(0 == result) {
134 result = memcmp(b0, b1, r0);
135 }
136 }
137
138 return result;
139 }
140
141
main(int argc,char ** argv)142 int main(int argc, char** argv)
143 {
144 char inpFilename[256] = { 0 };
145 char lz4Filename[256] = { 0 };
146 char decFilename[256] = { 0 };
147
148 if(argc < 2) {
149 printf("Please specify input filename\n");
150 return 0;
151 }
152
153 snprintf(inpFilename, 256, "%s", argv[1]);
154 snprintf(lz4Filename, 256, "%s.lz4s-%d", argv[1], 0);
155 snprintf(decFilename, 256, "%s.lz4s-%d.dec", argv[1], 0);
156
157 printf("inp = [%s]\n", inpFilename);
158 printf("lz4 = [%s]\n", lz4Filename);
159 printf("dec = [%s]\n", decFilename);
160
161 // compress
162 {
163 FILE* inpFp = fopen(inpFilename, "rb");
164 FILE* outFp = fopen(lz4Filename, "wb");
165
166 test_compress(outFp, inpFp);
167
168 fclose(outFp);
169 fclose(inpFp);
170 }
171
172 // decompress
173 {
174 FILE* inpFp = fopen(lz4Filename, "rb");
175 FILE* outFp = fopen(decFilename, "wb");
176
177 test_decompress(outFp, inpFp);
178
179 fclose(outFp);
180 fclose(inpFp);
181 }
182
183 // verify
184 {
185 FILE* inpFp = fopen(inpFilename, "rb");
186 FILE* decFp = fopen(decFilename, "rb");
187
188 const int cmp = compare(inpFp, decFp);
189 if(0 == cmp) {
190 printf("Verify : OK\n");
191 } else {
192 printf("Verify : NG\n");
193 }
194
195 fclose(decFp);
196 fclose(inpFp);
197 }
198
199 return 0;
200 }
201