[ldm] Add CHAR_OFFSET in hash function and extend header size
This commit is contained in:
Stella Lau
parent
8de82b6eb0
commit
92bed4a7e0
@ -28,6 +28,7 @@
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#define RUN_MASK ((1U<<RUN_BITS)-1)
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#define COMPUTE_STATS
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#define CHECKSUM_CHAR_OFFSET 2
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//#define RUN_CHECKS
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//#define LDM_DEBUG
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@ -191,11 +192,14 @@ static U32 getChecksum(const char *data, U32 len) {
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s1 = s2 = 0;
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for (i = 0; i < (len - 4); i += 4) {
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s2 += (4 * (s1 + buf[i])) + (3 * buf[i + 1]) +
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(2 * buf[i + 2]) + (buf[i + 3]);
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s1 += buf[i] + buf[i + 1] + buf[i + 2] + buf[i + 3];
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(2 * buf[i + 2]) + (buf[i + 3]) +
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(10 * CHECKSUM_CHAR_OFFSET);
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s1 += buf[i] + buf[i + 1] + buf[i + 2] + buf[i + 3] +
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+ (4 * CHECKSUM_CHAR_OFFSET);
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}
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for(; i < len; i++) {
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s1 += buf[i];
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s1 += buf[i] + CHECKSUM_CHAR_OFFSET;
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s2 += s1;
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}
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return (s1 & 0xffff) + (s2 << 16);
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@ -213,7 +217,7 @@ static U32 getChecksum(const char *data, U32 len) {
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static U32 updateChecksum(U32 sum, U32 len,
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schar toRemove, schar toAdd) {
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U32 s1 = (sum & 0xffff) - toRemove + toAdd;
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U32 s2 = (sum >> 16) - (toRemove * len) + s1;
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U32 s2 = (sum >> 16) - ((toRemove + CHECKSUM_CHAR_OFFSET) * len) + s1;
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return (s1 & 0xffff) + (s2 << 16);
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}
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@ -344,9 +348,9 @@ static unsigned countMatchLength(const BYTE *pIn, const BYTE *pMatch,
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return (unsigned)(pIn - pStart);
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}
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void LDM_readHeader(const void *src, size_t *compressSize,
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size_t *decompressSize) {
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const U32 *ip = (const U32 *)src;
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void LDM_readHeader(const void *src, U64 *compressSize,
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U64 *decompressSize) {
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const U64 *ip = (const U64 *)src;
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*compressSize = *ip++;
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*decompressSize = *ip;
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}
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@ -3,8 +3,8 @@
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#include <stddef.h> /* size_t */
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#define LDM_COMPRESS_SIZE 4
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#define LDM_DECOMPRESS_SIZE 4
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#define LDM_COMPRESS_SIZE 8
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#define LDM_DECOMPRESS_SIZE 8
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#define LDM_HEADER_SIZE ((LDM_COMPRESS_SIZE)+(LDM_DECOMPRESS_SIZE))
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/**
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@ -85,8 +85,8 @@ static int compress(const char *fname, const char *oname) {
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// Write compress and decompress size to header
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// TODO: should depend on LDM_DECOMPRESS_SIZE write32
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memcpy(dst, &compressSize, 4);
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memcpy(dst + 4, &(statbuf.st_size), 4);
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memcpy(dst, &compressSize, 8);
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memcpy(dst + 8, &(statbuf.st_size), 8);
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#ifdef DEBUG
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printf("Compressed size: %zu\n", compressSize);
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@ -267,202 +267,3 @@ int main(int argc, const char *argv[]) {
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verify(inpFilename, decFilename);
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return 0;
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}
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#if 0
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static size_t compress_file(FILE *in, FILE *out, size_t *size_in,
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size_t *size_out) {
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char *src, *buf = NULL;
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size_t r = 1;
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size_t size, n, k, count_in = 0, count_out = 0, offset, frame_size = 0;
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src = malloc(BUF_SIZE);
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if (!src) {
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printf("Not enough memory\n");
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goto cleanup;
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}
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size = BUF_SIZE + LDM_HEADER_SIZE;
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buf = malloc(size);
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if (!buf) {
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printf("Not enough memory\n");
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goto cleanup;
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}
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for (;;) {
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k = fread(src, 1, BUF_SIZE, in);
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if (k == 0)
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break;
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count_in += k;
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n = LDM_compress(src, buf, k, BUF_SIZE);
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// n = k;
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// offset += n;
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offset = k;
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count_out += k;
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// k = fwrite(src, 1, offset, out);
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k = fwrite(buf, 1, offset, out);
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if (k < offset) {
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if (ferror(out))
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printf("Write failed\n");
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else
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printf("Short write\n");
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goto cleanup;
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}
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}
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*size_in = count_in;
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*size_out = count_out;
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r = 0;
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cleanup:
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free(src);
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free(buf);
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return r;
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}
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static size_t decompress_file(FILE *in, FILE *out) {
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void *src = malloc(BUF_SIZE);
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void *dst = NULL;
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size_t dst_capacity = BUF_SIZE;
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size_t ret = 1;
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size_t bytes_written = 0;
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if (!src) {
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perror("decompress_file(src)");
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goto cleanup;
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}
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while (ret != 0) {
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/* Load more input */
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size_t src_size = fread(src, 1, BUF_SIZE, in);
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void *src_ptr = src;
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void *src_end = src_ptr + src_size;
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if (src_size == 0 || ferror(in)) {
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printf("(TODO): Decompress: not enough input or error reading file\n");
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//TODO
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ret = 0;
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goto cleanup;
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}
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/* Allocate destination buffer if it hasn't been allocated already */
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if (!dst) {
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dst = malloc(dst_capacity);
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if (!dst) {
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perror("decompress_file(dst)");
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goto cleanup;
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}
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}
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// TODO
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/* Decompress:
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* Continue while there is more input to read.
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*/
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while (src_ptr != src_end && ret != 0) {
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// size_t dst_size = src_size;
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size_t dst_size = LDM_decompress(src, dst, src_size, dst_capacity);
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size_t written = fwrite(dst, 1, dst_size, out);
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// printf("Writing %zu bytes\n", dst_size);
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bytes_written += dst_size;
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if (written != dst_size) {
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printf("Decompress: Failed to write to file\n");
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goto cleanup;
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}
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src_ptr += src_size;
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src_size = src_end - src_ptr;
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}
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/* Update input */
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}
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printf("Wrote %zu bytes\n", bytes_written);
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cleanup:
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free(src);
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free(dst);
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return ret;
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}
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int main2(int argc, char *argv[]) {
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char inpFilename[256] = { 0 };
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char ldmFilename[256] = { 0 };
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char decFilename[256] = { 0 };
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if (argc < 2) {
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printf("Please specify input filename\n");
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return 0;
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}
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snprintf(inpFilename, 256, "%s", argv[1]);
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snprintf(ldmFilename, 256, "%s.ldm", argv[1]);
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snprintf(decFilename, 256, "%s.ldm.dec", argv[1]);
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printf("inp = [%s]\n", inpFilename);
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printf("ldm = [%s]\n", ldmFilename);
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printf("dec = [%s]\n", decFilename);
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/* compress */
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{
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FILE *inpFp = fopen(inpFilename, "rb");
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FILE *outFp = fopen(ldmFilename, "wb");
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size_t sizeIn = 0;
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size_t sizeOut = 0;
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size_t ret;
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printf("compress : %s -> %s\n", inpFilename, ldmFilename);
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ret = compress_file(inpFp, outFp, &sizeIn, &sizeOut);
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if (ret) {
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printf("compress : failed with code %zu\n", ret);
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return ret;
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}
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printf("%s: %zu → %zu bytes, %.1f%%\n",
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inpFilename, sizeIn, sizeOut,
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(double)sizeOut / sizeIn * 100);
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printf("compress : done\n");
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fclose(outFp);
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fclose(inpFp);
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}
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/* decompress */
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{
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FILE *inpFp = fopen(ldmFilename, "rb");
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FILE *outFp = fopen(decFilename, "wb");
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size_t ret;
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printf("decompress : %s -> %s\n", ldmFilename, decFilename);
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ret = decompress_file(inpFp, outFp);
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if (ret) {
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printf("decompress : failed with code %zu\n", ret);
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return ret;
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}
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printf("decompress : done\n");
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fclose(outFp);
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fclose(inpFp);
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}
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/* verify */
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{
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FILE *inpFp = fopen(inpFilename, "rb");
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FILE *decFp = fopen(decFilename, "rb");
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printf("verify : %s <-> %s\n", inpFilename, decFilename);
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const int cmp = compare(inpFp, decFp);
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if(0 == cmp) {
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printf("verify : OK\n");
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} else {
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printf("verify : NG\n");
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}
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fclose(decFp);
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fclose(inpFp);
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}
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return 0;
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}
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#endif
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@ -53,6 +53,11 @@ U32 LDM_read32(const void *ptr) {
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return *(const U32 *)ptr;
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}
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//TODO: endianness?
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void LDM_write64(void *memPtr, U64 value) {
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memcpy(memPtr, &value, sizeof(value));
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}
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U64 LDM_read64(const void *ptr) {
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return *(const U64 *)ptr;
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}
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@ -21,5 +21,7 @@ void LDM_copy8(void *dst, const void *src);
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uint8_t LDM_readByte(const void *ptr);
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void LDM_write64(void *memPtr, uint64_t value);
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#endif /* LDM_UTIL_H */
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