xref: /netbsd-src/usr.bin/sort/fsort.c (revision f75f5aae154fcd0572e8889e4fea2a51d67bbf08)
1 /*	$NetBSD: fsort.c,v 1.45 2009/10/09 20:32:57 dsl 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 1.45 2009/10/09 20:32:57 dsl 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