diff options
Diffstat (limited to 'src/cmd/compress')
| -rwxr-xr-x | src/cmd/compress/compress.c | 1274 | ||||
| -rwxr-xr-x | src/cmd/compress/mkfile | 15 |
2 files changed, 1289 insertions, 0 deletions
diff --git a/src/cmd/compress/compress.c b/src/cmd/compress/compress.c new file mode 100755 index 00000000..808762ca --- /dev/null +++ b/src/cmd/compress/compress.c @@ -0,0 +1,1274 @@ +/* + * compress - File compression ala IEEE Computer, June 1984. + * + * Algorithm from "A Technique for High Performance Data Compression", + * Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19. + * + * Usage: compress [-dfvc] [-b bits] [file ...] + * Inputs: + * -b: limit the max number of bits/code. + * -c: write output on stdout, don't remove original. + * -d: decompress instead. + * -f: Forces output file to be generated, even if one already + * exists, and even if no space is saved by compressing. + * If -f is not used, the user will be prompted if stdin is + * a tty, otherwise, the output file will not be overwritten. + * -v: Write compression statistics + * + * file ...: Files to be compressed. If none specified, stdin is used. + * Outputs: + * file.Z: Compressed form of file with same mode, owner, and utimes + * or stdout (if stdin used as input) + * + * Assumptions: + * When filenames are given, replaces with the compressed version + * (.Z suffix) only if the file decreases in size. + * Algorithm: + * Modified Lempel-Ziv method (LZW). Basically finds common + * substrings and replaces them with a variable size code. This is + * deterministic, and can be done on the fly. Thus, the decompression + * procedure needs no input table, but tracks the way the table was built. + + * Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas) + * Jim McKie (decvax!mcvax!jim) + * Steve Davies (decvax!vax135!petsd!peora!srd) + * Ken Turkowski (decvax!decwrl!turtlevax!ken) + * James A. Woods (decvax!ihnp4!ames!jaw) + * Joe Orost (decvax!vax135!petsd!joe) + */ + +#ifndef USED +# define USED(x) if(x);else +#endif + +#define _PLAN9_SOURCE +#define _BSD_EXTENSION +#define _POSIX_SOURCE + +#include <u.h> +#include <stdio.h> +#include <ctype.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <signal.h> +#include <utime.h> +#include <sys/types.h> +#include <sys/stat.h> + +#define min(a,b) ((a>b) ? b : a) + +#define BITS 16 +#define HSIZE 69001 /* 95% occupancy */ + +/* + * a code_int must be able to hold 2**BITS values of type int, and also -1 + */ +typedef long code_int; +typedef long count_int; + +static char rcs_ident[] = "$Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $"; + +uchar magic_header[] = { 0x1F, 0x9D }; /* 1F 9D */ + +/* Defines for third byte of header */ +#define BIT_MASK 0x1f +#define BLOCK_MASK 0x80 +/* Masks 0x40 and 0x20 are free. I think 0x20 should mean that there is + a fourth header byte (for expansion). +*/ +#define INIT_BITS 9 /* initial number of bits/code */ + +#define ARGVAL() (*++(*argv) || (--argc && *++argv)) + +int n_bits; /* number of bits/code */ +int maxbits = BITS; /* user settable max # bits/code */ +code_int maxcode; /* maximum code, given n_bits */ +code_int maxmaxcode = 1 << BITS; /* should NEVER generate this code */ + +#define MAXCODE(n_bits) ((1 << (n_bits)) - 1) + +count_int htab[HSIZE]; +ushort codetab[HSIZE]; + +#define htabof(i) htab[i] +#define codetabof(i) codetab[i] + +code_int hsize = HSIZE; /* for dynamic table sizing */ +count_int fsize; + +/* + * To save much memory, we overlay the table used by compress() with those + * used by decompress(). The tab_prefix table is the same size and type + * as the codetab. The tab_suffix table needs 2**BITS characters. We + * get this from the beginning of htab. The output stack uses the rest + * of htab, and contains characters. There is plenty of room for any + * possible stack (stack used to be 8000 characters). + */ + +#define tab_prefixof(i) codetabof(i) +#define tab_suffixof(i) ((uchar *)(htab))[i] +#define de_stack ((uchar *)&tab_suffixof(1<<BITS)) + +code_int free_ent = 0; /* first unused entry */ +int exit_stat = 0; + +void cl_block(void); +void cl_hash(count_int); +void compress(void); +void copystat(char *, char *); +void decompress(void); +int foreground(void); +code_int getcode(void); +void onintr(int); +void oops(int); +void output(code_int); +void prratio(FILE *, long, long); +void version(void); +void writeerr(void); + +void +Usage(void) +{ +#ifdef DEBUG + fprintf(stderr,"Usage: compress [-cdfDV] [-b maxbits] [file ...]\n"); +#else + fprintf(stderr,"Usage: compress [-cdfvV] [-b maxbits] [file ...]\n"); +#endif /* DEBUG */ +} + +int debug = 0; +int nomagic = 0; /* Use a 3-byte magic number header, unless old file */ +int zcat_flg = 0; /* Write output on stdout, suppress messages */ +int quiet = 1; /* don't tell me about compression */ + +/* + * block compression parameters -- after all codes are used up, + * and compression rate changes, start over. + */ +int block_compress = BLOCK_MASK; +int clear_flg = 0; +long ratio = 0; +#define CHECK_GAP 10000 /* ratio check interval */ +count_int checkpoint = CHECK_GAP; +/* + * the next two codes should not be changed lightly, as they must not + * lie within the contiguous general code space. + */ +#define FIRST 257 /* first free entry */ +#define CLEAR 256 /* table clear output code */ + +int force = 0; +char ofname [100]; +#ifdef DEBUG +int verbose = 0; +#endif /* DEBUG */ +void (*bgnd_flag)(int); + +int do_decomp = 0; + +int +main(argc, argv) +int argc; +char **argv; +{ + int overwrite = 0; /* Do not overwrite unless given -f flag */ + char tempname[512]; + char **filelist, **fileptr; + char *cp; + struct stat statbuf; + + if ( (bgnd_flag = signal ( SIGINT, SIG_IGN )) != SIG_IGN ) { + signal(SIGINT, onintr); + signal(SIGSEGV, oops); + } + + filelist = fileptr = (char **)(malloc(argc * sizeof(*argv))); + *filelist = NULL; + + if((cp = strrchr(argv[0], '/')) != 0) + cp++; + else + cp = argv[0]; + if(strcmp(cp, "uncompress") == 0) + do_decomp = 1; + else if(strcmp(cp, "zcat") == 0) { + do_decomp = 1; + zcat_flg = 1; + } + + /* + * Argument Processing + * All flags are optional. + * -C generate output compatible with compress 2.0. + * -D debug + * -V print Version; debug verbose + * -b maxbits maxbits. If -b is specified, then maxbits MUST be + * given also. + * -c cat all output to stdout + * -d do_decomp + * -f force overwrite of output file + * -n no header: useful to uncompress old files + * -v unquiet + * if a string is left, must be an input filename. + */ + for (argc--, argv++; argc > 0; argc--, argv++) { + if (**argv == '-') { /* A flag argument */ + while (*++(*argv)) { /* Process all flags in this arg */ + switch (**argv) { + case 'C': + block_compress = 0; + break; +#ifdef DEBUG + case 'D': + debug = 1; + break; + case 'V': + verbose = 1; + version(); + break; +#else + case 'V': + version(); + break; +#endif + case 'b': + if (!ARGVAL()) { + fprintf(stderr, "Missing maxbits\n"); + Usage(); + exit(1); + } + maxbits = atoi(*argv); + goto nextarg; + case 'c': + zcat_flg = 1; + break; + case 'd': + do_decomp = 1; + break; + case 'f': + case 'F': + overwrite = 1; + force = 1; + break; + case 'n': + nomagic = 1; + break; + case 'q': + quiet = 1; + break; + case 'v': + quiet = 0; + break; + default: + fprintf(stderr, "Unknown flag: '%c'; ", **argv); + Usage(); + exit(1); + } + } + } else { /* Input file name */ + *fileptr++ = *argv; /* Build input file list */ + *fileptr = NULL; + /* process nextarg; */ + } +nextarg: + continue; + } + + if(maxbits < INIT_BITS) maxbits = INIT_BITS; + if (maxbits > BITS) maxbits = BITS; + maxmaxcode = 1 << maxbits; + + if (*filelist != NULL) { + for (fileptr = filelist; *fileptr; fileptr++) { + exit_stat = 0; + if (do_decomp != 0) { /* DECOMPRESSION */ + /* Check for .Z suffix */ + if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") != 0) { + /* No .Z: tack one on */ + strcpy(tempname, *fileptr); + strcat(tempname, ".Z"); + *fileptr = tempname; + } + /* Open input file */ + if ((freopen(*fileptr, "r", stdin)) == NULL) { + perror(*fileptr); + continue; + } + /* Check the magic number */ + if (nomagic == 0) { + if ((getchar() != (magic_header[0] & 0xFF)) + || (getchar() != (magic_header[1] & 0xFF))) { + fprintf(stderr, "%s: not in compressed format\n", + *fileptr); + continue; + } + maxbits = getchar(); /* set -b from file */ + block_compress = maxbits & BLOCK_MASK; + maxbits &= BIT_MASK; + maxmaxcode = 1 << maxbits; + if(maxbits > BITS) { + fprintf(stderr, + "%s: compressed with %d bits, can only handle %d bits\n", + *fileptr, maxbits, BITS); + continue; + } + } + /* Generate output filename */ + strcpy(ofname, *fileptr); + ofname[strlen(*fileptr) - 2] = '\0'; /* Strip off .Z */ + } else { /* COMPRESSION */ + if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") == 0) { + fprintf(stderr, + "%s: already has .Z suffix -- no change\n", + *fileptr); + continue; + } + /* Open input file */ + if ((freopen(*fileptr, "r", stdin)) == NULL) { + perror(*fileptr); + continue; + } + (void) stat(*fileptr, &statbuf); + fsize = (long) statbuf.st_size; + /* + * tune hash table size for small files -- ad hoc, + * but the sizes match earlier #defines, which + * serve as upper bounds on the number of output codes. + */ + hsize = HSIZE; + if (fsize < (1 << 12)) + hsize = min(5003, HSIZE); + else if (fsize < (1 << 13)) + hsize = min(9001, HSIZE); + else if (fsize < (1 << 14)) + hsize = min (18013, HSIZE); + else if (fsize < (1 << 15)) + hsize = min (35023, HSIZE); + else if (fsize < 47000) + hsize = min (50021, HSIZE); + + /* Generate output filename */ + strcpy(ofname, *fileptr); +#ifndef BSD4_2 + if ((cp=strrchr(ofname,'/')) != NULL) + cp++; + else + cp = ofname; + /* + *** changed 12 to 25; should be NAMELEN-3, but I don't want + * to fight the headers. ehg 5 Nov 92 ** + */ + if (strlen(cp) > 25) { + fprintf(stderr, "%s: filename too long to tack on .Z\n", + cp); + continue; + } +#endif + strcat(ofname, ".Z"); + } + /* Check for overwrite of existing file */ + if (overwrite == 0 && zcat_flg == 0 && + stat(ofname, &statbuf) == 0) { + char response[2]; + + response[0] = 'n'; + fprintf(stderr, "%s already exists;", ofname); + if (foreground()) { + fprintf(stderr, + " do you wish to overwrite %s (y or n)? ", + ofname); + fflush(stderr); + (void) read(2, response, 2); + while (response[1] != '\n') + if (read(2, response+1, 1) < 0) { + /* Ack! */ + perror("stderr"); + break; + } + } + if (response[0] != 'y') { + fprintf(stderr, "\tnot overwritten\n"); + continue; + } + } + if(zcat_flg == 0) { /* Open output file */ + if (freopen(ofname, "w", stdout) == NULL) { + perror(ofname); + continue; + } + if(!quiet) + fprintf(stderr, "%s: ", *fileptr); + } + + /* Actually do the compression/decompression */ + if (do_decomp == 0) + compress(); +#ifndef DEBUG + else + decompress(); +#else + else if (debug == 0) + decompress(); + else + printcodes(); + if (verbose) + dump_tab(); +#endif /* DEBUG */ + if(zcat_flg == 0) { + copystat(*fileptr, ofname); /* Copy stats */ + if (exit_stat == 1 || !quiet) + putc('\n', stderr); + } + } + } else { /* Standard input */ + if (do_decomp == 0) { + compress(); +#ifdef DEBUG + if(verbose) + dump_tab(); +#endif + if(!quiet) + putc('\n', stderr); + } else { + /* Check the magic number */ + if (nomagic == 0) { + if ((getchar()!=(magic_header[0] & 0xFF)) + || (getchar()!=(magic_header[1] & 0xFF))) { + fprintf(stderr, "stdin: not in compressed format\n"); + exit(1); + } + maxbits = getchar(); /* set -b from file */ + block_compress = maxbits & BLOCK_MASK; + maxbits &= BIT_MASK; + maxmaxcode = 1 << maxbits; + fsize = 100000; /* assume stdin large for USERMEM */ + if(maxbits > BITS) { + fprintf(stderr, + "stdin: compressed with %d bits, can only handle %d bits\n", + maxbits, BITS); + exit(1); + } + } +#ifndef DEBUG + decompress(); +#else + if (debug == 0) + decompress(); + else + printcodes(); + if (verbose) + dump_tab(); +#endif /* DEBUG */ + } + } + exit(exit_stat); + return 0; +} + +static int offset; +long in_count = 1; /* length of input */ +long bytes_out; /* length of compressed output */ +long out_count = 0; /* # of codes output (for debugging) */ + +/* + * compress stdin to stdout + * + * Algorithm: use open addressing double hashing (no chaining) on the + * prefix code / next character combination. We do a variant of Knuth's + * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime + * secondary probe. Here, the modular division first probe is gives way + * to a faster exclusive-or manipulation. Also do block compression with + * an adaptive reset, whereby the code table is cleared when the compression + * ratio decreases, but after the table fills. The variable-length output + * codes are re-sized at this point, and a special CLEAR code is generated + * for the decompressor. Late addition: construct the table according to + * file size for noticeable speed improvement on small files. Please direct + * questions about this implementation to ames!jaw. + */ +void +compress(void) +{ + code_int ent, hsize_reg; + code_int i; + int c, disp, hshift; + long fcode; + + if (nomagic == 0) { + putchar(magic_header[0]); + putchar(magic_header[1]); + putchar((char)(maxbits | block_compress)); + if(ferror(stdout)) + writeerr(); + } + offset = 0; + bytes_out = 3; /* includes 3-byte header mojo */ + out_count = 0; + clear_flg = 0; + ratio = 0; + in_count = 1; + checkpoint = CHECK_GAP; + maxcode = MAXCODE(n_bits = INIT_BITS); + free_ent = (block_compress? FIRST: 256); + + ent = getchar (); + + hshift = 0; + for (fcode = (long)hsize; fcode < 65536L; fcode *= 2) + hshift++; + hshift = 8 - hshift; /* set hash code range bound */ + + hsize_reg = hsize; + cl_hash( (count_int) hsize_reg); /* clear hash table */ + + while ((c = getchar()) != EOF) { + in_count++; + fcode = (long) (((long) c << maxbits) + ent); + i = ((c << hshift) ^ ent); /* xor hashing */ + + if (htabof (i) == fcode) { + ent = codetabof(i); + continue; + } else if ((long)htabof(i) < 0 ) /* empty slot */ + goto nomatch; + disp = hsize_reg - i; /* secondary hash (after G. Knott) */ + if (i == 0) + disp = 1; +probe: + if ((i -= disp) < 0) + i += hsize_reg; + + if (htabof (i) == fcode) { + ent = codetabof(i); + continue; + } + if ((long)htabof(i) > 0) + goto probe; +nomatch: + output((code_int)ent); + out_count++; + ent = c; + if (free_ent < maxmaxcode) { + codetabof(i) = free_ent++; /* code -> hashtable */ + htabof(i) = fcode; + } else if ((count_int)in_count >= checkpoint && block_compress) + cl_block (); + } + /* + * Put out the final code. + */ + output( (code_int)ent ); + out_count++; + output( (code_int)-1 ); + + /* + * Print out stats on stderr + */ + if(zcat_flg == 0 && !quiet) { +#ifdef DEBUG + fprintf( stderr, + "%ld chars in, %ld codes (%ld bytes) out, compression factor: ", + in_count, out_count, bytes_out ); + prratio( stderr, in_count, bytes_out ); + fprintf( stderr, "\n"); + fprintf( stderr, "\tCompression as in compact: " ); + prratio( stderr, in_count-bytes_out, in_count ); + fprintf( stderr, "\n"); + fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n", + free_ent - 1, n_bits ); +#else /* !DEBUG */ + fprintf( stderr, "Compression: " ); + prratio( stderr, in_count-bytes_out, in_count ); +#endif /* DEBUG */ + } + if(bytes_out > in_count) /* exit(2) if no savings */ + exit_stat = 2; +} + +/* + * TAG( output ) + * + * Output the given code. + * Inputs: + * code: A n_bits-bit integer. If == -1, then EOF. This assumes + * that n_bits =< (long)wordsize - 1. + * Outputs: + * Outputs code to the file. + * Assumptions: + * Chars are 8 bits long. + * Algorithm: + * Maintain a BITS character long buffer (so that 8 codes will + * fit in it exactly). When the buffer fills up empty it and start over. + */ + +static char buf[BITS]; + +uchar lmask[9] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00}; +uchar rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff}; + +void +output( code ) +code_int code; +{ +#ifdef DEBUG + static int col = 0; +#endif + int r_off = offset, bits= n_bits; + char *bp = buf; + +#ifdef DEBUG + if (verbose) + fprintf(stderr, "%5d%c", code, + (col+=6) >= 74? (col = 0, '\n'): ' '); +#endif + if (code >= 0) { + /* + * byte/bit numbering on the VAX is simulated by the + * following code + */ + /* + * Get to the first byte. + */ + bp += (r_off >> 3); + r_off &= 7; + /* + * Since code is always >= 8 bits, only need to mask the first + * hunk on the left. + */ + *bp = (*bp & rmask[r_off]) | (code << r_off) & lmask[r_off]; + bp++; + bits -= 8 - r_off; + code >>= 8 - r_off; + /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */ + if ( bits >= 8 ) { + *bp++ = code; + code >>= 8; + bits -= 8; + } + /* Last bits. */ + if(bits) + *bp = code; + + offset += n_bits; + if ( offset == (n_bits << 3) ) { + bp = buf; + bits = n_bits; + bytes_out += bits; + do { + putchar(*bp++); + } while(--bits); + offset = 0; + } + + /* + * If the next entry is going to be too big for the code size, + * then increase it, if possible. + */ + if ( free_ent > maxcode || (clear_flg > 0)) { + /* + * Write the whole buffer, because the input side won't + * discover the size increase until after it has read it. + */ + if ( offset > 0 ) { + if( fwrite( buf, 1, n_bits, stdout ) != n_bits) + writeerr(); + bytes_out += n_bits; + } + offset = 0; + + if ( clear_flg ) { + maxcode = MAXCODE (n_bits = INIT_BITS); + clear_flg = 0; + } else { + n_bits++; + if ( n_bits == maxbits ) + maxcode = maxmaxcode; + else + maxcode = MAXCODE(n_bits); + } +#ifdef DEBUG + if ( debug ) { + fprintf(stderr, + "\nChange to %d bits\n", n_bits); + col = 0; + } +#endif + } + } else { + /* + * At EOF, write the rest of the buffer. + */ + if ( offset > 0 ) + fwrite( buf, 1, (offset + 7) / 8, stdout ); + bytes_out += (offset + 7) / 8; + offset = 0; + fflush( stdout ); +#ifdef DEBUG + if ( verbose ) + fprintf( stderr, "\n" ); +#endif + if( ferror( stdout ) ) + writeerr(); + } +} + +/* + * Decompress stdin to stdout. This routine adapts to the codes in the + * file building the "string" table on-the-fly; requiring no table to + * be stored in the compressed file. The tables used herein are shared + * with those of the compress() routine. See the definitions above. + */ +void +decompress(void) +{ + int finchar; + code_int code, oldcode, incode; + uchar *stackp; + + /* + * As above, initialize the first 256 entries in the table. + */ + maxcode = MAXCODE(n_bits = INIT_BITS); + for (code = 255; code >= 0; code--) { + tab_prefixof(code) = 0; + tab_suffixof(code) = (uchar)code; + } + free_ent = (block_compress? FIRST: 256); + + finchar = oldcode = getcode(); + if(oldcode == -1) /* EOF already? */ + return; /* Get out of here */ + putchar((char)finchar); /* first code must be 8 bits = char */ + if(ferror(stdout)) /* Crash if can't write */ + writeerr(); + stackp = de_stack; + + while ((code = getcode()) > -1) { + if ((code == CLEAR) && block_compress) { + for (code = 255; code >= 0; code--) + tab_prefixof(code) = 0; + clear_flg = 1; + free_ent = FIRST - 1; + if ((code = getcode()) == -1) /* O, untimely death! */ + break; + } + incode = code; + /* + * Special case for KwKwK string. + */ + if (code >= free_ent) { + *stackp++ = finchar; + code = oldcode; + } + + /* + * Generate output characters in reverse order + */ + while (code >= 256) { + *stackp++ = tab_suffixof(code); + code = tab_prefixof(code); + } + *stackp++ = finchar = tab_suffixof(code); + + /* + * And put them out in forward order + */ + do { + putchar(*--stackp); + } while (stackp > de_stack); + + /* + * Generate the new entry. + */ + if ( (code=free_ent) < maxmaxcode ) { + tab_prefixof(code) = (ushort)oldcode; + tab_suffixof(code) = finchar; + free_ent = code+1; + } + /* + * Remember previous code. + */ + oldcode = incode; + } + fflush(stdout); + if(ferror(stdout)) + writeerr(); +} + +/* + * TAG( getcode ) + * + * Read one code from the standard input. If EOF, return -1. + * Inputs: + * stdin + * Outputs: + * code or -1 is returned. + */ +code_int +getcode() +{ + int r_off, bits; + code_int code; + static int offset = 0, size = 0; + static uchar buf[BITS]; + uchar *bp = buf; + + if ( clear_flg > 0 || offset >= size || free_ent > maxcode ) { + /* + * If the next entry will be too big for the current code + * size, then we must increase the size. This implies reading + * a new buffer full, too. + */ + if ( free_ent > maxcode ) { + n_bits++; + if ( n_bits == maxbits ) + maxcode = maxmaxcode; /* won't get any bigger now */ + else + maxcode = MAXCODE(n_bits); + } + if ( clear_flg > 0) { + maxcode = MAXCODE(n_bits = INIT_BITS); + clear_flg = 0; + } + size = fread(buf, 1, n_bits, stdin); + if (size <= 0) + return -1; /* end of file */ + offset = 0; + /* Round size down to integral number of codes */ + size = (size << 3) - (n_bits - 1); + } + r_off = offset; + bits = n_bits; + /* + * Get to the first byte. + */ + bp += (r_off >> 3); + r_off &= 7; + /* Get first part (low order bits) */ + code = (*bp++ >> r_off); + bits -= (8 - r_off); + r_off = 8 - r_off; /* now, offset into code word */ + /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */ + if (bits >= 8) { + code |= *bp++ << r_off; + r_off += 8; + bits -= 8; + } + /* high order bits. */ + code |= (*bp & rmask[bits]) << r_off; + offset += n_bits; + return code; +} + +#ifdef DEBUG +printcodes() +{ + /* + * Just print out codes from input file. For debugging. + */ + code_int code; + int col = 0, bits; + + bits = n_bits = INIT_BITS; + maxcode = MAXCODE(n_bits); + free_ent = ((block_compress) ? FIRST : 256 ); + while ( ( code = getcode() ) >= 0 ) { + if ( (code == CLEAR) && block_compress ) { + free_ent = FIRST - 1; + clear_flg = 1; + } + else if ( free_ent < maxmaxcode ) + free_ent++; + if ( bits != n_bits ) { + fprintf(stderr, "\nChange to %d bits\n", n_bits ); + bits = n_bits; + col = 0; + } + fprintf(stderr, "%5d%c", code, (col+=6) >= 74 ? (col = 0, '\n') : ' ' ); + } + putc( '\n', stderr ); + exit( 0 ); +} + +code_int sorttab[1<<BITS]; /* sorted pointers into htab */ + +#define STACK_SIZE 15000 + +dump_tab() /* dump string table */ +{ + int i, first, c, ent; + int stack_top = STACK_SIZE; + + if(do_decomp == 0) { /* compressing */ + int flag = 1; + + for(i=0; i<hsize; i++) { /* build sort pointers */ + if((long)htabof(i) >= 0) { + sorttab[codetabof(i)] = i; + } + } + first = block_compress ? FIRST : 256; + for(i = first; i < free_ent; i++) { + fprintf(stderr, "%5d: \"", i); + de_stack[--stack_top] = '\n'; + de_stack[--stack_top] = '"'; + stack_top = in_stack((htabof(sorttab[i])>>maxbits)&0xff, + stack_top); + for(ent=htabof(sorttab[i]) & ((1<<maxbits)-1); + ent > 256; + ent=htabof(sorttab[ent]) & ((1<<maxbits)-1)) { + stack_top = in_stack(htabof(sorttab[ent]) >> maxbits, + stack_top); + } + stack_top = in_stack(ent, stack_top); + fwrite( &de_stack[stack_top], 1, STACK_SIZE-stack_top, stderr); + stack_top = STACK_SIZE; + } + } else if(!debug) { /* decompressing */ + + for ( i = 0; i < free_ent; i++ ) { + ent = i; + c = tab_suffixof(ent); + if ( isascii(c) && isprint(c) ) + fprintf( stderr, "%5d: %5d/'%c' \"", + ent, tab_prefixof(ent), c ); + else + fprintf( stderr, "%5d: %5d/\\%03o \"", + ent, tab_prefixof(ent), c ); + de_stack[--stack_top] = '\n'; + de_stack[--stack_top] = '"'; + for ( ; ent != NULL; + ent = (ent >= FIRST ? tab_prefixof(ent) : NULL) ) { + stack_top = in_stack(tab_suffixof(ent), stack_top); + } + fwrite( &de_stack[stack_top], 1, STACK_SIZE - stack_top, stderr ); + stack_top = STACK_SIZE; + } + } +} + +int +in_stack(int c, int stack_top) +{ + if ( (isascii(c) && isprint(c) && c != '\\') || c == ' ' ) { + de_stack[--stack_top] = c; + } else { + switch( c ) { + case '\n': de_stack[--stack_top] = 'n'; break; + case '\t': de_stack[--stack_top] = 't'; break; + case '\b': de_stack[--stack_top] = 'b'; break; + case '\f': de_stack[--stack_top] = 'f'; break; + case '\r': de_stack[--stack_top] = 'r'; break; + case '\\': de_stack[--stack_top] = '\\'; break; + default: + de_stack[--stack_top] = '0' + c % 8; + de_stack[--stack_top] = '0' + (c / 8) % 8; + de_stack[--stack_top] = '0' + c / 64; + break; + } + de_stack[--stack_top] = '\\'; + } + return stack_top; +} +#endif /* DEBUG */ + +void +writeerr(void) +{ + perror(ofname); + unlink(ofname); + exit(1); +} + +void +copystat(ifname, ofname) +char *ifname, *ofname; +{ + int mode; + time_t timep[2]; /* should be struct utimbuf */ + struct stat statbuf; + + fclose(stdout); + if (stat(ifname, &statbuf)) { /* Get stat on input file */ + perror(ifname); + return; + } + if (!S_ISREG(statbuf.st_mode)) { + if (quiet) + fprintf(stderr, "%s: ", ifname); + fprintf(stderr, " -- not a regular file: unchanged"); + exit_stat = 1; + } else if (exit_stat == 2 && !force) { + /* No compression: remove file.Z */ + if (!quiet) + fprintf(stderr, " -- file unchanged"); + } else { /* Successful Compression */ + exit_stat = 0; + mode = statbuf.st_mode & 0777; + if (chmod(ofname, mode)) /* Copy modes */ + perror(ofname); + /* Copy ownership */ + chown(ofname, statbuf.st_uid, statbuf.st_gid); + timep[0] = statbuf.st_atime; + timep[1] = statbuf.st_mtime; + /* Update last accessed and modified times */ + utime(ofname, (struct utimbuf *)timep); +// if (unlink(ifname)) /* Remove input file */ +// perror(ifname); + return; /* success */ + } + + /* Unsuccessful return -- one of the tests failed */ + if (unlink(ofname)) + perror(ofname); +} + +/* + * This routine returns 1 if we are running in the foreground and stderr + * is a tty. + */ +int +foreground(void) +{ + if(bgnd_flag) /* background? */ + return 0; + else /* foreground */ + return isatty(2); /* and stderr is a tty */ +} + +void +onintr(int x) +{ + USED(x); + unlink(ofname); + exit(1); +} + +void +oops(int x) /* wild pointer -- assume bad input */ +{ + USED(x); + if (do_decomp == 1) + fprintf(stderr, "uncompress: corrupt input\n"); + unlink(ofname); + exit(1); +} + +void +cl_block(void) /* table clear for block compress */ +{ + long rat; + + checkpoint = in_count + CHECK_GAP; +#ifdef DEBUG + if ( debug ) { + fprintf ( stderr, "count: %ld, ratio: ", in_count ); + prratio ( stderr, in_count, bytes_out ); + fprintf ( stderr, "\n"); + } +#endif /* DEBUG */ + + if (in_count > 0x007fffff) { /* shift will overflow */ + rat = bytes_out >> 8; + if (rat == 0) /* Don't divide by zero */ + rat = 0x7fffffff; + else + rat = in_count / rat; + } else + rat = (in_count << 8) / bytes_out; /* 8 fractional bits */ + if (rat > ratio) + ratio = rat; + else { + ratio = 0; +#ifdef DEBUG + if (verbose) + dump_tab(); /* dump string table */ +#endif + cl_hash((count_int)hsize); + free_ent = FIRST; + clear_flg = 1; + output((code_int)CLEAR); +#ifdef DEBUG + if (debug) + fprintf(stderr, "clear\n"); +#endif /* DEBUG */ + } +} + +void +cl_hash(count_int hsize) /* reset code table */ +{ + count_int *htab_p = htab+hsize; + long i; + long m1 = -1; + + i = hsize - 16; + do { /* might use Sys V memset(3) here */ + *(htab_p-16) = m1; + *(htab_p-15) = m1; + *(htab_p-14) = m1; + *(htab_p-13) = m1; + *(htab_p-12) = m1; + *(htab_p-11) = m1; + *(htab_p-10) = m1; + *(htab_p-9) = m1; + *(htab_p-8) = m1; + *(htab_p-7) = m1; + *(htab_p-6) = m1; + *(htab_p-5) = m1; + *(htab_p-4) = m1; + *(htab_p-3) = m1; + *(htab_p-2) = m1; + *(htab_p-1) = m1; + htab_p -= 16; + } while ((i -= 16) >= 0); + for ( i += 16; i > 0; i-- ) + *--htab_p = m1; +} + +void +prratio(stream, num, den) +FILE *stream; +long num, den; +{ + int q; /* Doesn't need to be long */ + + if(num > 214748L) /* 2147483647/10000 */ + q = num / (den / 10000L); + else + q = 10000L * num / den; /* Long calculations, though */ + if (q < 0) { + putc('-', stream); + q = -q; + } + fprintf(stream, "%d.%02d%%", q / 100, q % 100); +} + +void +version(void) +{ + fprintf(stderr, "%s\n", rcs_ident); + fprintf(stderr, "Options: "); +#ifdef DEBUG + fprintf(stderr, "DEBUG, "); +#endif +#ifdef BSD4_2 + fprintf(stderr, "BSD4_2, "); +#endif + fprintf(stderr, "BITS = %d\n", BITS); +} + +/* + * The revision-history novel: + * + * $Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $ + * $Log: compress.c,v $ + * Revision 4.0 85/07/30 12:50:00 joe + * Removed ferror() calls in output routine on every output except first. + * Prepared for release to the world. + * + * Revision 3.6 85/07/04 01:22:21 joe + * Remove much wasted storage by overlaying hash table with the tables + * used by decompress: tab_suffix[1<<BITS], stack[8000]. Updated USERMEM + * computations. Fixed dump_tab() DEBUG routine. + * + * Revision 3.5 85/06/30 20:47:21 jaw + * Change hash function to use exclusive-or. Rip out hash cache. These + * speedups render the megamemory version defunct, for now. Make decoder + * stack global. Parts of the RCS trunks 2.7, 2.6, and 2.1 no longer apply. + * + * Revision 3.4 85/06/27 12:00:00 ken + * Get rid of all floating-point calculations by doing all compression ratio + * calculations in fixed point. + * + * Revision 3.3 85/06/24 21:53:24 joe + * Incorporate portability suggestion for M_XENIX. Got rid of text on #else + * and #endif lines. Cleaned up #ifdefs for vax and interdata. + * + * Revision 3.2 85/06/06 21:53:24 jaw + * Incorporate portability suggestions for Z8000, IBM PC/XT from mailing list. + * Default to "quiet" output (no compression statistics). + * + * Revision 3.1 85/05/12 18:56:13 jaw + * Integrate decompress() stack speedups (from early pointer mods by McKie). + * Repair multi-file USERMEM gaffe. Unify 'force' flags to mimic semantics + * of SVR2 'pack'. Streamline block-compress table clear logic. Increase + * output byte count by magic number size. + * + * Revision 3.0 84/11/27 11:50:00 petsd!joe + * Set HSIZE depending on BITS. Set BITS depending on USERMEM. Unrolled + * loops in clear routines. Added "-C" flag for 2.0 compatibility. Used + * unsigned compares on Perkin-Elmer. Fixed foreground check. + * + * Revision 2.7 84/11/16 19:35:39 ames!jaw + * Cache common hash codes based on input statistics; this improves + * performance for low-density raster images. Pass on #ifdef bundle + * from Turkowski. + * + * Revision 2.6 84/11/05 19:18:21 ames!jaw + * Vary size of hash tables to reduce time for small files. + * Tune PDP-11 hash function. + * + * Revision 2.5 84/10/30 20:15:14 ames!jaw + * Junk chaining; replace with the simpler (and, on the VAX, faster) + * double hashing, discussed within. Make block compression standard. + * + * Revision 2.4 84/10/16 11:11:11 ames!jaw + * Introduce adaptive reset for block compression, to boost the rate + * another several percent. (See mailing list notes.) + * + * Revision 2.3 84/09/22 22:00:00 petsd!joe + * Implemented "-B" block compress. Implemented REVERSE sorting of tab_next. + * Bug fix for last bits. Changed fwrite to putchar loop everywhere. + * + * Revision 2.2 84/09/18 14:12:21 ames!jaw + * Fold in news changes, small machine typedef from thomas, + * #ifdef interdata from joe. + * + * Revision 2.1 84/09/10 12:34:56 ames!jaw + * Configured fast table lookup for 32-bit machines. + * This cuts user time in half for b <= FBITS, and is useful for news batching + * from VAX to PDP sites. Also sped up decompress() [fwrite->putc] and + * added signal catcher [plus beef in writeerr()] to delete effluvia. + * + * Revision 2.0 84/08/28 22:00:00 petsd!joe + * Add check for foreground before prompting user. Insert maxbits into + * compressed file. Force file being uncompressed to end with ".Z". + * Added "-c" flag and "zcat". Prepared for release. + * + * Revision 1.10 84/08/24 18:28:00 turtlevax!ken + * Will only compress regular files (no directories), added a magic number + * header (plus an undocumented -n flag to handle old files without headers), + * added -f flag to force overwriting of possibly existing destination file, + * otherwise the user is prompted for a response. Will tack on a .Z to a + * filename if it doesn't have one when decompressing. Will only replace + * file if it was compressed. + * + * Revision 1.9 84/08/16 17:28:00 turtlevax!ken + * Removed scanargs(), getopt(), added .Z extension and unlimited number of + * filenames to compress. Flags may be clustered (-Ddvb12) or separated + * (-D -d -v -b 12), or combination thereof. Modes and other status is + * copied with copystat(). -O bug for 4.2 seems to have disappeared with + * 1.8. + * + * Revision 1.8 84/08/09 23:15:00 joe + * Made it compatible with vax version, installed jim's fixes/enhancements + * + * Revision 1.6 84/08/01 22:08:00 joe + * Sped up algorithm significantly by sorting the compress chain. + * + * Revision 1.5 84/07/13 13:11:00 srd + * Added C version of vax asm routines. Changed structure to arrays to + * save much memory. Do unsigned compares where possible (faster on + * Perkin-Elmer) + * + * Revision 1.4 84/07/05 03:11:11 thomas + * Clean up the code a little and lint it. (Lint complains about all + * the regs used in the asm, but I'm not going to "fix" this.) + * + * Revision 1.3 84/07/05 02:06:54 thomas + * Minor fixes. + * + * Revision 1.2 84/07/05 00:27:27 thomas + * Add variable bit length output. + */ diff --git a/src/cmd/compress/mkfile b/src/cmd/compress/mkfile new file mode 100755 index 00000000..5af1958d --- /dev/null +++ b/src/cmd/compress/mkfile @@ -0,0 +1,15 @@ +<$PLAN9/src/mkhdr + +TARG=\ + compress \ + zcat \ + uncompress + +$O.uncompress:Q: $O.compress + cp $prereq $target + +$O.zcat:Q: $O.compress + cp $prereq $target + +<$PLAN9/src/mkmany + |