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Diffstat (limited to 'usr.bin/locate/code/locate.code.c')
| -rw-r--r-- | usr.bin/locate/code/locate.code.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/usr.bin/locate/code/locate.code.c b/usr.bin/locate/code/locate.code.c new file mode 100644 index 000000000000..08bbee9a2b1f --- /dev/null +++ b/usr.bin/locate/code/locate.code.c @@ -0,0 +1,233 @@ +/* + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1995-2022 Wolfram Schneider <wosch@FreeBSD.org> + * Copyright (c) 1989, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * James A. Woods. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * PURPOSE: sorted list compressor (works with a modified 'find' + * to encode/decode a filename database) + * + * USAGE: bigram < list > bigrams + * process bigrams (see updatedb) > common_bigrams + * code common_bigrams < list > squozen_list + * + * METHOD: Uses 'front compression' (see ";login:", Volume 8, Number 1 + * February/March 1983, p. 8). Output format is, per line, an + * offset differential count byte followed by a partially bigram- + * encoded ascii residue. A bigram is a two-character sequence, + * the first 128 most common of which are encoded in one byte. + * + * EXAMPLE: For simple front compression with no bigram encoding, + * if the input is... then the output is... + * + * /usr/src 0 /usr/src + * /usr/src/cmd/aardvark.c 8 /cmd/aardvark.c + * /usr/src/cmd/armadillo.c 14 armadillo.c + * /usr/tmp/zoo 5 tmp/zoo + * + * The codes are: + * + * 0-28 likeliest differential counts + offset to make nonnegative + * 30 switch code for out-of-range count to follow in next word + * 31 an 8 bit char followed + * 128-255 bigram codes (128 most common, as determined by 'updatedb') + * 32-127 single character (printable) ascii residue (ie, literal) + * + * The locate database store any character except newline ('\n') + * and NUL ('\0'). The 8-bit character support don't wast extra + * space until you have characters in file names less than 32 + * or greather than 127. + * + * + * SEE ALSO: updatedb.sh, ../bigram/locate.bigram.c + * + * AUTHOR: James A. Woods, Informatics General Corp., + * NASA Ames Research Center, 10/82 + * 8-bit file names characters: + * Wolfram Schneider, Berlin September 1996 + */ + +#include <sys/param.h> +#include <err.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <unistd.h> +#include "locate.h" + +#define BGBUFSIZE (NBG * 2) /* size of bigram buffer */ + +u_char buf1[LOCATE_PATH_MAX] = " "; +u_char buf2[LOCATE_PATH_MAX]; +u_char bigrams[BGBUFSIZE + 1] = { 0 }; + +/* use a lookup array instead a function, 3x faster than linear search */ +int big [UCHAR_MAX + 1][UCHAR_MAX + 1]; +#define BGINDEX(x) (big[(u_char)*x][(u_char)*(x + 1)]) + +void usage(void); + +int +main(int argc, char *argv[]) +{ + u_char *cp, *oldpath, *path; + int ch, code, count, diffcount, oldcount; + u_int i, j; + FILE *fp; + + while ((ch = getopt(argc, argv, "")) != -1) + switch(ch) { + default: + usage(); + } + argc -= optind; + argv += optind; + + if (argc != 1) + usage(); + + if ((fp = fopen(argv[0], "r")) == NULL) + err(1, "%s", argv[0]); + + /* First copy bigram array to stdout. */ + if (fgets(bigrams, BGBUFSIZE + 1, fp) == NULL) { + if (!feof(fp) || ferror(fp)) + err(1, "get bigram array"); + } + + if (fwrite(bigrams, 1, BGBUFSIZE, stdout) != BGBUFSIZE) + err(1, "stdout"); + (void)fclose(fp); + + /* init lookup table */ + for (i = 0; i < UCHAR_MAX + 1; i++) + for (j = 0; j < UCHAR_MAX + 1; j++) + big[i][j] = -1; + + for (cp = bigrams, i = 0; *cp != '\0'; i += 2, cp += 2) + big[(u_char)*cp][(u_char)*(cp + 1)] = i; + + oldpath = buf1; + path = buf2; + oldcount = 0; + + while (fgets(path, sizeof(buf2), stdin) != NULL) { + + /* skip empty lines */ + if (*path == '\n') + continue; + + /* remove newline */ + for (cp = path; *cp != '\0'; cp++) { + /* chop newline */ + if (*cp == '\n') + *cp = '\0'; + } + + /* Skip longest common prefix. */ + for (cp = path; *cp == *oldpath; cp++, oldpath++) + if (*cp == '\0') + break; + + count = cp - path; + diffcount = count - oldcount + OFFSET; + oldcount = count; + if (diffcount < 0 || diffcount > 2 * OFFSET) { + if (putchar(SWITCH) == EOF || + putw(diffcount, stdout) == EOF) + err(1, "stdout"); + } else + if (putchar(diffcount) == EOF) + err(1, "stdout"); + + while (*cp != '\0') { + /* print *two* characters */ + + if ((code = BGINDEX(cp)) != -1) { + /* + * print *one* as bigram + * Found, so mark byte with + * parity bit. + */ + if (putchar((code / 2) | PARITY) == EOF) + err(1, "stdout"); + cp += 2; + } + + else { + for (i = 0; i < 2; i++) { + if (*cp == '\0') + break; + + /* print umlauts in file names */ + if (*cp < ASCII_MIN || + *cp > ASCII_MAX) { + if (putchar(UMLAUT) == EOF || + putchar(*cp++) == EOF) + err(1, "stdout"); + } + + else { + /* normal character */ + if(putchar(*cp++) == EOF) + err(1, "stdout"); + } + } + + } + } + + if (path == buf1) { /* swap pointers */ + path = buf2; + oldpath = buf1; + } else { + path = buf1; + oldpath = buf2; + } + } + + /* Non-zero status if there were errors */ + if (fflush(stdout) != 0 || ferror(stdout)) + errx(1, "stdout"); + + exit(0); +} + +void +usage(void) +{ + (void)fprintf(stderr, + "usage: locate.code common_bigrams < list > squozen_list\n"); + exit(1); +} |