xref: /netbsd/usr.bin/sort/fsort.c (revision 6550d01e)
1 /*	$NetBSD: fsort.c,v 1.47 2010/02/05 21:58:41 enami 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 __RCSID("$NetBSD: fsort.c,v 1.47 2010/02/05 21:58:41 enami Exp $");
75 
76 #include <stdlib.h>
77 #include <string.h>
78 
79 #define SALIGN(n) ((n+sizeof(length_t)-1) & ~(sizeof(length_t)-1))
80 
81 void
82 fsort(struct filelist *filelist, int nfiles, FILE *outfp, struct field *ftbl)
83 {
84 	RECHEADER **keylist;
85 	RECHEADER **keypos, **keyp;
86 	RECHEADER *buffer;
87 	size_t bufsize = DEFBUFSIZE;
88 	u_char *bufend;
89 	int mfct = 0;
90 	int c, nelem;
91 	get_func_t get;
92 	RECHEADER *crec;
93 	RECHEADER *nbuffer;
94 	FILE *fp, *tmp_fp;
95 	int file_no;
96 	int max_recs = DEBUG('m') ? 16 : MAXNUM;
97 
98 	buffer = allocrec(NULL, bufsize);
99 	bufend = (u_char *)buffer + bufsize;
100 	/* Allocate double length keymap for radix_sort */
101 	keylist = malloc(2 * max_recs * sizeof(*keylist));
102 	if (buffer == NULL || keylist == NULL)
103 		err(2, "failed to malloc initial buffer or keylist");
104 
105 	if (SINGL_FLD)
106 		/* Key and data are one! */
107 		get = makeline;
108 	else
109 		/* Key (merged key fields) added before data */
110 		get = makekey;
111 
112 	file_no = 0;
113 	fp = fopen(filelist->names[0], "r");
114 	if (fp == NULL)
115 		err(2, "%s", filelist->names[0]);
116 
117 	/* Loop through reads of chunk of input files that get sorted
118 	 * and then merged together. */
119 	for (;;) {
120 		keypos = keylist;
121 		nelem = 0;
122 		crec = buffer;
123 		makeline_copydown(crec);
124 
125 		/* Loop reading records */
126 		for (;;) {
127 			c = get(fp, crec, bufend, ftbl);
128 			/* 'c' is 0, EOF or BUFFEND */
129 			if (c == 0) {
130 				/* Save start of key in input buffer */
131 				*keypos++ = crec;
132 				if (++nelem == max_recs) {
133 					c = BUFFEND;
134 					break;
135 				}
136 				crec = (RECHEADER *)(crec->data + SALIGN(crec->length));
137 				continue;
138 			}
139 			if (c == EOF) {
140 				/* try next file */
141 				if (++file_no >= nfiles)
142 					/* no more files */
143 					break;
144 				fp = fopen(filelist->names[file_no], "r");
145 				if (fp == NULL)
146 					err(2, "%s", filelist->names[file_no]);
147 				continue;
148 			}
149 			if (nelem >= max_recs
150 			    || (bufsize >= MAXBUFSIZE && nelem > 8))
151 				/* Need to sort and save this lot of data */
152 				break;
153 
154 			/* c == BUFFEND, and we can process more data */
155 			/* Allocate a larger buffer for this lot of data */
156 			bufsize *= 2;
157 			nbuffer = allocrec(buffer, bufsize);
158 			if (!nbuffer) {
159 				err(2, "failed to realloc buffer to %zu bytes",
160 					bufsize);
161 			}
162 
163 			/* patch up keylist[] */
164 			for (keyp = &keypos[-1]; keyp >= keylist; keyp--)
165 				*keyp = nbuffer + (*keyp - buffer);
166 
167 			crec = nbuffer + (crec - buffer);
168 			buffer = nbuffer;
169 			bufend = (u_char *)buffer + bufsize;
170 		}
171 
172 		/* Sort this set of records */
173 		radix_sort(keylist, keylist + max_recs, nelem);
174 
175 		if (c == EOF && mfct == 0) {
176 			/* all the data is (sorted) in the buffer */
177 			append(keylist, nelem, outfp,
178 			    DEBUG('k') ? putkeydump : putline);
179 			break;
180 		}
181 
182 		/* Save current data to a temporary file for a later merge */
183 		if (nelem != 0) {
184 			tmp_fp = ftmp();
185 			append(keylist, nelem, tmp_fp, putrec);
186 			save_for_merge(tmp_fp, geteasy, ftbl);
187 		}
188 		mfct = 1;
189 
190 		if (c == EOF) {
191 			/* merge to output file */
192 			merge_sort(outfp,
193 			    DEBUG('k') ? putkeydump : putline, ftbl);
194 			break;
195 		}
196 	}
197 
198 	free(keylist);
199 	keylist = NULL;
200 	free(buffer);
201 	buffer = NULL;
202 }
203