Add start of C based decoder
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2 changed files with 149 additions and 0 deletions
4
Makefile
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4
Makefile
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CFLAGS=`pkg-config --libs --cflags zlib`
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unpack: unpack.c
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gcc -Wall $(CFLAGS) -o unpack unpack.c
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unpack.c
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unpack.c
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#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <zlib.h>
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#define CHUNK 1024
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struct node {
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struct node *next;
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unsigned int path;
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unsigned int children[];
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};
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static int
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load_dictionary(FILE *source, unsigned char **dictionary) {
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int ret;
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unsigned have;
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z_stream strm;
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unsigned char in[CHUNK];
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int read = 0;
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unsigned char *buf = malloc(sizeof(char) * CHUNK);
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*dictionary = buf;
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printf("unpacking string dictionary\n");
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/* allocate inflate state */
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strm.zalloc = Z_NULL;
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strm.zfree = Z_NULL;
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strm.opaque = Z_NULL;
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strm.avail_in = 0;
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strm.next_in = Z_NULL;
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ret = inflateInit(&strm);
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if (ret != Z_OK) {
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printf("ERROR\n");
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return ret;
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}
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/* decompress until deflate stream ends or end of file */
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do {
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strm.avail_in = fread(in, 1, CHUNK, source);
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if (ferror(source)) {
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(void)inflateEnd(&strm);
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return -1;
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}
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if (strm.avail_in == 0) {
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printf("read entire file\n");
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break;
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}
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strm.next_in = in;
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/* run inflate() on input until output buffer not full */
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do {
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strm.avail_out = CHUNK;
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strm.next_out = buf;
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ret = inflate(&strm, Z_NO_FLUSH);
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assert(ret != Z_STREAM_ERROR); /* state not clobbered */
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switch (ret) {
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case Z_NEED_DICT:
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printf("NEED ERROR\n");
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ret = Z_DATA_ERROR; /* and fall through */
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case Z_DATA_ERROR:
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printf("DATA ERROR\n");
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case Z_MEM_ERROR:
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(void)inflateEnd(&strm);
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printf("MEMORY ERROR\n");
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return -1;
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}
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have = CHUNK - strm.avail_out;
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read += CHUNK - strm.avail_out;
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} while (strm.avail_out == 0);
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// read += CHUNK;
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/* done when inflate() says it's done */
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} while (ret != Z_STREAM_END);
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printf("data is:\n");
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int i;
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for (i=0; i < read; i++) {
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if (buf[i] == '\0') {
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putchar('\n');
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} else {
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putchar(buf[i]);
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}
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}
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// rewind back to unused zlib bytes
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if (fseek(source, (long) strm.avail_in * -1, SEEK_CUR)) {
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printf("Error seeking back in stream\n");
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return -1;
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}
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printf ("dictionary stats:\n");
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printf ("\tcompressed size: %zu\n", ftell(source));
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printf ("\tuncompressed size: %d\n", read);
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inflateEnd(&strm);
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return ret == Z_STREAM_END ? 0 : -1;
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}
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static int
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load_node_list(FILE *stream, struct node **list) {
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unsigned char buf[CHUNK];
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size_t read;
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struct node *np = malloc(sizeof(struct node));
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*list = np;
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read = fread(buf, 1, CHUNK, stream);
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printf("Read %zu bytes\n", read);
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return 0;
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}
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int
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main(int argc, char **argv) {
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FILE *fp;
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unsigned char *dictionary;
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struct node *list;
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if (argc != 2) {
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printf("usage: unpack <bin file>\n");
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return -1;
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}
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fp = fopen(argv[1], "r");
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if (fp == NULL) {
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printf("error: unable to open file: %s\n", argv[1]);
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return -1;
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}
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if (load_dictionary(fp, &dictionary)) {
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printf("dictionary inflation failed. exiting\n");
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return -1;
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}
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if (load_node_list(fp, &list)) {
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printf("node list parsing failed. exiting\n");
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return -1;
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}
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return 0;
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}
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