uint32_t file_lz77_compress (char *filename_in, char *filename_out, size_t malloc_size, uint8_t pointer_length_width)
{
FILE *in, *out;
uint8_t *uncompressed_text, *compressed_text;
uint32_t uncompressed_size, compressed_size;
in = fopen(filename_in, "r");
if(in == NULL)
return 0;
uncompressed_size = fsize(in);
uncompressed_text = malloc(uncompressed_size);
if((uncompressed_size != fread(uncompressed_text, 1, uncompressed_size, in)))
return 0;
fclose(in);
compressed_text = malloc(malloc_size);
compressed_size = lz77_compress(uncompressed_text, uncompressed_size, compressed_text, pointer_length_width);
out = fopen(filename_out, "w");
if(out == NULL)
return 0;
if((compressed_size != fwrite(compressed_text, 1, compressed_size, out)))
return 0;
fclose(out);
return compressed_size;
}
/**
* 压缩一个文本文件,然后将压缩之后的内容保存为另外一个文件
*/
void lz77_compress_test(){
FILE *file = NULL;
file = fopen("D:/c_note.txt", "rb");
if (file == NULL) {
printf("open file err\n");
return;
}
fseek(file, 0, SEEK_END);
long size = ftell(file);
fseek(file, 0, SEEK_SET);
printf("file 'size : %ld\n", size);
const unsigned char *buf = (unsigned char *)malloc(size * sizeof(unsigned char));
fread((void *)buf, size, sizeof(unsigned char), file);
unsigned char *compressed;
int compressed_size = 0;
if((compressed_size = lz77_compress(buf, &compressed, size)) <= 0) {
printf("%s\n", "compress fail");
return;
}
printf("compressed content size : %d\n", compressed_size);
FILE *file2 = NULL;
file2 = fopen("D:/c_note.lz77", "wb");
if (file2 == NULL) {
printf("%s\n", "write file open err");
return;
}
fwrite((const void *)(compressed), compressed_size, sizeof(unsigned char), file2);
printf("%s\n", "write file end");
fclose(file2);
fclose(file);
return;
}
int main(int argc, char **argv)
{
FILE *fp;
unsigned char original[DATSIZ], *compressed, *restored;
int csize, osize, rsize, c, i;
/*****************************************************************************
* *
* Read some data to compress. *
* *
*****************************************************************************/
if ((fp = fopen("sample.txt", "r")) == NULL)
return 1;
i = 0;
while ((c = getc(fp)) != EOF && i < DATSIZ) {
original[i] = c;
i++;
}
osize = i;
fclose(fp);
/*****************************************************************************
* *
* Compress the data using Huffman coding. *
* *
*****************************************************************************/
fprintf(stdout, "Compressing with Huffman coding\n");
fprintf(stdout, "Compressing...");
if ((csize = huffman_compress(original, &compressed, osize)) < 0) {
fprintf(stdout, "\n");
return 1;
}
fprintf(stdout, "Done\n");
fprintf(stdout, "Uncompressing...");
if ((rsize = huffman_uncompress(compressed, &restored)) < 0) {
fprintf(stdout, "\n");
free(compressed);
return 1;
}
fprintf(stdout, "Done\n");
fprintf(stdout, "osize=%d, csize=%d, rsize=%d\n", osize, csize, rsize);
if (rsize != osize) {
fprintf(stdout, "Data was not properly restored\n");
free(compressed);
free(restored);
return 1;
}
else {
for (i = 0; i < rsize; i++) {
if (original[i] != restored[i]) {
fprintf(stdout,
"Data was not properly restored\n");
if (isgraph(original[i]))
fprintf(stdout, "original[%d]=\"%c\"\n",
i, original[i]);
else
fprintf(stdout, "original[%d]=0x%02x\n",
i, original[i]);
if (isgraph(restored[i]))
fprintf(stdout, "restored[%d]=\"%c\"\n",
i, restored[i]);
else
fprintf(stdout, "restored[%d]=0x%02x\n",
i, restored[i]);
free(compressed);
free(restored);
return 1;
}
}
}
fprintf(stdout, "Data was restored OK\n");
free(compressed);
free(restored);
/*****************************************************************************
* *
* Compress some data using LZ77. *
* *
*****************************************************************************/
fprintf(stdout, "Compressing with LZ77\n");
fprintf(stdout, "Compressing...");
if ((csize = lz77_compress(original, &compressed, osize)) < 0)
return 1;
fprintf(stdout, "Done\n");
fprintf(stdout, "Uncompressing...");
if ((rsize = lz77_uncompress(compressed, &restored)) < 0) {
fprintf(stdout, "\n");
free(compressed);
return 1;
}
fprintf(stdout, "Done\n");
fprintf(stdout, "osize=%d, csize=%d, rsize=%d\n", osize, csize, rsize);
if (rsize != osize) {
fprintf(stdout, "Data was not properly restored\n");
free(compressed);
free(restored);
return 1;
}
else {
for (i = 0; i < rsize; i++) {
if (original[i] != restored[i]) {
fprintf(stdout,
"Data was not properly restored\n");
if (isgraph(original[i]))
fprintf(stdout, "original[%d]=\"%c\"\n",
i, original[i]);
else
fprintf(stdout, "original[%d]=0x%02x\n",
i, original[i]);
if (isgraph(restored[i]))
fprintf(stdout, "restored[%d]=\"%c\"\n",
i, restored[i]);
else
fprintf(stdout, "restored[%d]=0x%02x\n",
i, restored[i]);
free(compressed);
free(restored);
return 1;
}
}
}
fprintf(stdout, "Data was restored OK\n");
free(compressed);
free(restored);
return 0;
}