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fsort.c revision 1.32.6.1
      1 /*	$NetBSD: fsort.c,v 1.32.6.1 2009/10/14 20:41:53 sborrill Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2000-2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Ben Harris and Jaromir Dolecek.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*-
     33  * Copyright (c) 1993
     34  *	The Regents of the University of California.  All rights reserved.
     35  *
     36  * This code is derived from software contributed to Berkeley by
     37  * Peter McIlroy.
     38  *
     39  * Redistribution and use in source and binary forms, with or without
     40  * modification, are permitted provided that the following conditions
     41  * are met:
     42  * 1. Redistributions of source code must retain the above copyright
     43  *    notice, this list of conditions and the following disclaimer.
     44  * 2. Redistributions in binary form must reproduce the above copyright
     45  *    notice, this list of conditions and the following disclaimer in the
     46  *    documentation and/or other materials provided with the distribution.
     47  * 3. Neither the name of the University nor the names of its contributors
     48  *    may be used to endorse or promote products derived from this software
     49  *    without specific prior written permission.
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     61  * SUCH DAMAGE.
     62  */
     63 
     64 /*
     65  * Read in a block of records (until 'enough').
     66  * sort, write to temp file.
     67  * Merge sort temp files into output file
     68  * Small files miss out the temp file stage.
     69  * Large files might get multiple merges.
     70  */
     71 #include "sort.h"
     72 #include "fsort.h"
     73 
     74 #ifndef lint
     75 __RCSID("$NetBSD: fsort.c,v 1.32.6.1 2009/10/14 20:41:53 sborrill Exp $");
     76 __SCCSID("@(#)fsort.c	8.1 (Berkeley) 6/6/93");
     77 #endif /* not lint */
     78 
     79 #include <stdlib.h>
     80 #include <string.h>
     81 
     82 #define SALIGN(n) ((n+sizeof(length_t)-1) & ~(sizeof(length_t)-1))
     83 
     84 void
     85 fsort(struct filelist *filelist, int nfiles, FILE *outfp, struct field *ftbl)
     86 {
     87 	RECHEADER **keylist;
     88 	RECHEADER **keypos, **keyp;
     89 	RECHEADER *buffer;
     90 	size_t bufsize = DEFBUFSIZE;
     91 	u_char *bufend;
     92 	int mfct = 0;
     93 	int c, nelem;
     94 	get_func_t get;
     95 	RECHEADER *crec;
     96 	RECHEADER *nbuffer;
     97 	FILE *fp, *tmp_fp;
     98 	int file_no;
     99 	int max_recs = DEBUG('m') ? 16 : MAXNUM;
    100 
    101 	buffer = malloc(bufsize);
    102 	bufend = (u_char *)buffer + bufsize;
    103 	/* Allocate double length keymap for radix_sort */
    104 	keylist = malloc(2 * max_recs * sizeof(*keylist));
    105 	if (buffer == NULL || keylist == NULL)
    106 		err(2, "failed to malloc initial buffer or keylist");
    107 
    108 	if (SINGL_FLD)
    109 		/* Key and data are one! */
    110 		get = makeline;
    111 	else
    112 		/* Key (merged key fields) added before data */
    113 		get = makekey;
    114 
    115 	file_no = 0;
    116 	fp = fopen(filelist->names[0], "r");
    117 	if (fp == NULL)
    118 		err(2, "%s", filelist->names[0]);
    119 
    120 	/* Loop through reads of chunk of input files that get sorted
    121 	 * and then merged together. */
    122 	for (;;) {
    123 		keypos = keylist;
    124 		nelem = 0;
    125 		crec = buffer;
    126 		makeline_copydown(crec);
    127 
    128 		/* Loop reading records */
    129 		for (;;) {
    130 			c = get(fp, crec, bufend, ftbl);
    131 			/* 'c' is 0, EOF or BUFFEND */
    132 			if (c == 0) {
    133 				/* Save start of key in input buffer */
    134 				*keypos++ = crec;
    135 				if (++nelem == max_recs) {
    136 					c = BUFFEND;
    137 					break;
    138 				}
    139 				crec = (RECHEADER *)(crec->data + SALIGN(crec->length));
    140 				continue;
    141 			}
    142 			if (c == EOF) {
    143 				/* try next file */
    144 				if (++file_no >= nfiles)
    145 					/* no more files */
    146 					break;
    147 				fp = fopen(filelist->names[file_no], "r");
    148 				if (fp == NULL)
    149 					err(2, "%s", filelist->names[file_no]);
    150 				continue;
    151 			}
    152 			if (nelem >= max_recs
    153 			    || (bufsize >= MAXBUFSIZE && nelem > 8))
    154 				/* Need to sort and save this lot of data */
    155 				break;
    156 
    157 			/* c == BUFFEND, and we can process more data */
    158 			/* Allocate a larger buffer for this lot of data */
    159 			bufsize *= 2;
    160 			nbuffer = realloc(buffer, bufsize);
    161 			if (!nbuffer) {
    162 				err(2, "failed to realloc buffer to %zu bytes",
    163 					bufsize);
    164 			}
    165 
    166 			/* patch up keylist[] */
    167 			for (keyp = &keypos[-1]; keyp >= keylist; keyp--)
    168 				*keyp = nbuffer + (*keyp - buffer);
    169 
    170 			crec = nbuffer + (crec - buffer);
    171 			buffer = nbuffer;
    172 			bufend = (u_char *)buffer + bufsize;
    173 		}
    174 
    175 		/* Sort this set of records */
    176 		radix_sort(keylist, keylist + max_recs, nelem);
    177 
    178 		if (c == EOF && mfct == 0) {
    179 			/* all the data is (sorted) in the buffer */
    180 			append(keylist, nelem, outfp,
    181 			    DEBUG('k') ? putkeydump : putline);
    182 			break;
    183 		}
    184 
    185 		/* Save current data to a temporary file for a later merge */
    186 		if (nelem != 0) {
    187 			tmp_fp = ftmp();
    188 			append(keylist, nelem, tmp_fp, putrec);
    189 			save_for_merge(tmp_fp, geteasy, ftbl);
    190 		}
    191 		mfct = 1;
    192 
    193 		if (c == EOF) {
    194 			/* merge to output file */
    195 			merge_sort(outfp,
    196 			    DEBUG('k') ? putkeydump : putline, ftbl);
    197 			break;
    198 		}
    199 	}
    200 
    201 	free(keylist);
    202 	keylist = NULL;
    203 	free(buffer);
    204 	buffer = NULL;
    205 }
    206