diff options
Diffstat (limited to 'seek-bzip2/micro-bunzip.h')
| -rw-r--r-- | seek-bzip2/micro-bunzip.h | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/seek-bzip2/micro-bunzip.h b/seek-bzip2/micro-bunzip.h new file mode 100644 index 0000000..85b83da --- /dev/null +++ b/seek-bzip2/micro-bunzip.h @@ -0,0 +1,77 @@ +#ifndef __MICRO_BUNZIP_H__ +#define __MICRO_BUNZIP_H__ + +/* ---- Duplicated from micro-bzip.c -------------------------------------- */ + +#include <setjmp.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <limits.h> + +/* Constants for huffman coding */ +#define MAX_GROUPS 6 +#define GROUP_SIZE 50 /* 64 would have been more efficient */ +#define MAX_HUFCODE_BITS 20 /* Longest huffman code allowed */ +#define MAX_SYMBOLS 258 /* 256 literals + RUNA + RUNB */ +#define SYMBOL_RUNA 0 +#define SYMBOL_RUNB 1 + +/* Status return values */ +#define RETVAL_OK 0 +#define RETVAL_LAST_BLOCK (-1) +#define RETVAL_NOT_BZIP_DATA (-2) +#define RETVAL_UNEXPECTED_INPUT_EOF (-3) +#define RETVAL_UNEXPECTED_OUTPUT_EOF (-4) +#define RETVAL_DATA_ERROR (-5) +#define RETVAL_OUT_OF_MEMORY (-6) +#define RETVAL_OBSOLETE_INPUT (-7) + +/* Other housekeeping constants */ +#define IOBUF_SIZE 4096 + +/* This is what we know about each huffman coding group */ +struct group_data +{ + /* We have an extra slot at the end of limit[] for a sentinal value. */ + int limit[MAX_HUFCODE_BITS+1], base[MAX_HUFCODE_BITS], permute[MAX_SYMBOLS]; + int minLen, maxLen; +}; + +/* Structure holding all the housekeeping data, including IO buffers and + memory that persists between calls to bunzip */ +typedef struct +{ + /* State for interrupting output loop */ + int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent; + /* I/O tracking data (file handles, buffers, positions, etc.) */ + int in_fd, out_fd, inbufCount, inbufPos /*,outbufPos*/; + // james@jamestaylor.org: track relative position in input so we don't need tell + off_t position; + unsigned char *inbuf /*,*outbuf*/; + unsigned int inbufBitCount, inbufBits; + /* The CRC values stored in the block header and calculated from the data */ + unsigned int crc32Table[256], headerCRC, totalCRC, writeCRC; + /* Intermediate buffer and its size (in bytes) */ + unsigned int *dbuf, dbufSize; + /* These things are a bit too big to go on the stack */ + unsigned char selectors[32768]; /* nSelectors=15 bits */ + struct group_data groups[MAX_GROUPS]; /* huffman coding tables */ + /* For I/O error handling */ + jmp_buf jmpbuf; +} +bunzip_data; + +static char * const bunzip_errors[] = + { + NULL, "Bad file checksum", "Not bzip data", + "Unexpected input EOF", "Unexpected output EOF", "Data error", + "Out of memory", "Obsolete (pre 0.9.5) bzip format not supported." + }; + +/* ---- Forward declarations for micro-bzip.c ---------------------------- */ + +extern int get_next_block( bunzip_data *bd ); + +#endif |