1/*	$NetBSD: fsort.c,v 1.46 2009/11/06 18:34:22 joerg 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 1.46 2009/11/06 18:34:22 joerg 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
81void
82fsort(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