xref: /netbsd-src/usr.bin/sort/msort.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: msort.c,v 1.12 2003/03/20 16:13:03 jdolecek Exp $	*/
2 
3 /*-
4  * Copyright (c) 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Peter McIlroy.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include "sort.h"
40 #include "fsort.h"
41 
42 #ifndef lint
43 __RCSID("$NetBSD: msort.c,v 1.12 2003/03/20 16:13:03 jdolecek Exp $");
44 __SCCSID("@(#)msort.c	8.1 (Berkeley) 6/6/93");
45 #endif /* not lint */
46 
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 /* Subroutines using comparisons: merge sort and check order */
52 #define DELETE (1)
53 
54 typedef struct mfile {
55 	u_char *end;
56 	short flno;
57 	struct recheader rec[1];
58 } MFILE;
59 
60 static u_char *wts, *wts1 = NULL;
61 
62 static int cmp __P((RECHEADER *, RECHEADER *));
63 static int insert __P((struct mfile **, struct mfile **, int, int));
64 static void merge(int, int, get_func_t, FILE *, put_func_t, struct field *);
65 
66 void
67 fmerge(binno, top, filelist, nfiles, get, outfp, fput, ftbl)
68 	int binno, top;
69 	struct filelist *filelist;
70 	int nfiles;
71 	get_func_t get;
72 	FILE *outfp;
73 	put_func_t fput;
74 	struct field *ftbl;
75 {
76 	FILE *tout;
77 	int i, j, last;
78 	put_func_t put;
79 	struct tempfile *l_fstack;
80 
81 	wts = ftbl->weights;
82 	if (!UNIQUE && SINGL_FLD && ftbl->flags & F)
83 		wts1 = (ftbl->flags & R) ? Rascii : ascii;
84 
85 	if (!buffer) {
86 		buffer = malloc(bufsize);
87 		if (!buffer)
88 			err(2, "fmerge(): malloc");
89 
90 		if (!linebuf && !SINGL_FLD) {
91 			linebuf_size = DEFLLEN;
92 			linebuf = malloc(linebuf_size);
93 		}
94 	}
95 
96 	if (binno >= 0)
97 		l_fstack = fstack + top;
98 	else
99 		l_fstack = fstack;
100 
101 	while (nfiles) {
102 		put = putrec;
103 		for (j = 0; j < nfiles; j += MERGE_FNUM) {
104 			if (nfiles <= MERGE_FNUM) {
105 				tout = outfp;
106 				put = fput;
107 			}
108 			else
109 				tout = ftmp();
110 			last = min(MERGE_FNUM, nfiles - j);
111 			if (binno < 0) {
112 				for (i = 0; i < last; i++)
113 					if (!(l_fstack[i+MAXFCT-1-MERGE_FNUM].fp =
114 					    fopen(filelist->names[j+i], "r")))
115 						err(2, "%s",
116 							filelist->names[j+i]);
117 				merge(MAXFCT-1-MERGE_FNUM, last, get, tout, put, ftbl);
118 			} else {
119 				for (i = 0; i< last; i++)
120 					rewind(l_fstack[i+j].fp);
121 				merge(top+j, last, get, tout, put, ftbl);
122 			}
123 			if (nfiles > MERGE_FNUM)
124 				l_fstack[j/MERGE_FNUM].fp = tout;
125 		}
126 		nfiles = (nfiles + (MERGE_FNUM - 1)) / MERGE_FNUM;
127 		if (nfiles == 1)
128 			nfiles = 0;
129 		if (binno < 0) {
130 			binno = 0;
131 			get = geteasy;
132 			top = 0;
133 		}
134 	}
135 }
136 
137 static void
138 merge(infl0, nfiles, get, outfp, put, ftbl)
139 	int infl0, nfiles;
140 	get_func_t get;
141 	put_func_t put;
142 	FILE *outfp;
143 	struct field *ftbl;
144 {
145 	int c, i, j, nf = nfiles;
146 	struct mfile *flistb[MERGE_FNUM], **flist = flistb, *cfile;
147 	size_t availsz = bufsize;
148 	static void *bufs[MERGE_FNUM+1];
149 	static size_t bufs_sz[MERGE_FNUM+1];
150 
151 	/*
152 	 * We need nfiles + 1 buffers. One is 'buffer', the
153 	 * rest needs to be allocated.
154 	 */
155 	bufs[0] = buffer;
156 	bufs_sz[0] = bufsize;
157 	for(i=1; i < nfiles+1; i++) {
158 		if (bufs[i])
159 			continue;
160 
161 		bufs[i] = malloc(DEFLLEN);
162 		if (!bufs[i])
163 			err(2, "merge: malloc");
164 		bufs_sz[i] = DEFLLEN;
165 	}
166 
167 	for (i = j = 0; i < nfiles; i++, j++) {
168 		cfile = (struct mfile *) bufs[j];
169 		cfile->flno = infl0 + j;
170 		cfile->end = (u_char *) bufs[j] + bufs_sz[j];
171 		for (c = 1; c == 1;) {
172 			if (EOF == (c = get(cfile->flno, 0, NULL, nfiles,
173 			   cfile->rec, cfile->end, ftbl))) {
174 				--i;
175 				--nfiles;
176 				break;
177 			}
178 
179 			if (c == BUFFEND) {
180 				cfile = realloc(bufs[j], bufs_sz[j] *= 2);
181 				if (!cfile)
182 					err(2, "merge: realloc");
183 
184 				bufs[j] = (void *) cfile;
185 				cfile->end = (u_char *)cfile + bufs_sz[j];
186 
187 				c = 1;
188 				continue;
189 			}
190 
191 			if (i)
192 				c = insert(flist, &cfile, i, !DELETE);
193 			else
194 				flist[0] = cfile;
195 		}
196 	}
197 
198 	cfile = (struct mfile *) bufs[nf];
199 	cfile->flno = flist[0]->flno;
200 	cfile->end = (u_char *) cfile + bufs_sz[nf];
201 	while (nfiles) {
202 		for (c = 1; c == 1;) {
203 			if (EOF == (c = get(cfile->flno, 0, NULL, nfiles,
204 			   cfile->rec, cfile->end, ftbl))) {
205 				put(flist[0]->rec, outfp);
206 				if (--nfiles > 0) {
207 					flist++;
208 					cfile->flno = flist[0]->flno;
209 				}
210 				break;
211 			}
212 			if (c == BUFFEND) {
213 				char *oldbuf = (char *) cfile;
214 				availsz = (char *) cfile->end - oldbuf;
215 				availsz *= 2;
216 				cfile = realloc(oldbuf, availsz);
217 				if (!cfile)
218 					err(2, "merge: realloc");
219 
220 				for(i=0; i < nf+1; i++) {
221 					if (bufs[i] == oldbuf) {
222 						bufs[i] = (char *)cfile;
223 						bufs_sz[i] = availsz;
224 						break;
225 					}
226 				}
227 
228 				cfile->end = (u_char *)cfile + availsz;
229 				c = 1;
230 				continue;
231 			}
232 
233 			if (!(c = insert(flist, &cfile, nfiles, DELETE)))
234 				put(cfile->rec, outfp);
235 		}
236 	}
237 
238 	if (bufs_sz[0] > bufsize) {
239 		buffer = bufs[0];
240 		bufsize = bufs_sz[0];
241 	}
242 }
243 
244 /*
245  * if delete: inserts *rec in flist, deletes flist[0], and leaves it in *rec;
246  * otherwise just inserts *rec in flist.
247  */
248 static int
249 insert(flist, rec, ttop, delete)
250 	struct mfile **flist, **rec;
251 	int delete, ttop;			/* delete = 0 or 1 */
252 {
253 	struct mfile *tmprec = *rec;
254 	int mid, top = ttop, bot = 0, cmpv = 1;
255 
256 	for (mid = top/2; bot +1 != top; mid = (bot+top)/2) {
257 		cmpv = cmp(tmprec->rec, flist[mid]->rec);
258 		if (cmpv < 0)
259 			top = mid;
260 		else if (cmpv > 0)
261 			bot = mid;
262 		else {
263 			if (UNIQUE)
264 				break;
265 
266 			if (stable_sort) {
267 				/*
268 				 * Apply sort by fileno, to give priority
269 				 * to earlier specified files, hence providing
270 				 * more stable sort.
271 				 * If fileno is same, the new record should
272 				 * be put _after_ the previous entry.
273 				 */
274 				cmpv = tmprec->flno - flist[mid]->flno;
275 				if (cmpv >= 0)
276 					bot = mid;
277 				else /* cmpv == 0 */
278 					bot = mid - 1;
279 			} else {
280 				/* non-stable sort */
281 				bot = mid - 1;
282 			}
283 
284 			break;
285 		}
286 	}
287 
288 	if (delete) {
289 		if (UNIQUE) {
290 			if (!bot && cmpv)
291 				cmpv = cmp(tmprec->rec, flist[0]->rec);
292 			if (!cmpv)
293 				return (1);
294 		}
295 		tmprec = flist[0];
296 		if (bot)
297 			memmove(flist, flist+1, bot * sizeof(MFILE **));
298 		flist[bot] = *rec;
299 		*rec = tmprec;
300 		(*rec)->flno = flist[0]->flno;
301 		return (0);
302 	} else {
303 		if (!bot && !(UNIQUE && !cmpv)) {
304 			cmpv = cmp(tmprec->rec, flist[0]->rec);
305 			if (cmpv < 0)
306 				bot = -1;
307 		}
308 		if (UNIQUE && !cmpv)
309 			return (1);
310 		bot++;
311 		memmove(flist + bot+1, flist + bot,
312 		    (ttop - bot) * sizeof(MFILE **));
313 		flist[bot] = *rec;
314 		return (0);
315 	}
316 }
317 
318 /*
319  * check order on one file
320  */
321 void
322 order(filelist, get, ftbl)
323 	struct filelist *filelist;
324 	get_func_t get;
325 	struct field *ftbl;
326 {
327 	u_char *crec_end, *prec_end, *trec_end;
328 	int c;
329 	RECHEADER *crec, *prec, *trec;
330 
331 	if (!SINGL_FLD)
332 		linebuf = malloc(DEFLLEN);
333 	buffer = malloc(2 * (DEFLLEN + sizeof(TRECHEADER)));
334 	crec = (RECHEADER *) buffer;
335 	crec_end = buffer + DEFLLEN + sizeof(TRECHEADER);
336 	prec = (RECHEADER *) (buffer + DEFLLEN + sizeof(TRECHEADER));
337 	prec_end = buffer + 2*(DEFLLEN + sizeof(TRECHEADER));
338 	wts = ftbl->weights;
339 	if (SINGL_FLD && (ftbl->flags & F))
340 		wts1 = (ftbl->flags & R) ? Rascii : ascii;
341 	else
342 		wts1 = NULL;
343 	if (0 == get(-1, 0, filelist, 1, prec, prec_end, ftbl))
344 	while (0 == get(-1, 0, filelist, 1, crec, crec_end, ftbl)) {
345 		if (0 < (c = cmp(prec, crec))) {
346 			crec->data[crec->length-1] = 0;
347 			errx(1, "found disorder: %s", crec->data+crec->offset);
348 		}
349 		if (UNIQUE && !c) {
350 			crec->data[crec->length-1] = 0;
351 			errx(1, "found non-uniqueness: %s",
352 			    crec->data+crec->offset);
353 		}
354 		/*
355 		 * Swap pointers so that this record is on place pointed
356 		 * to by prec and new record is read to place pointed to by
357 		 * crec.
358 		 */
359 		trec = prec;
360 		prec = crec;
361 		crec = trec;
362 		trec_end = prec_end;
363 		prec_end = crec_end;
364 		crec_end = trec_end;
365 	}
366 	exit(0);
367 }
368 
369 static int
370 cmp(rec1, rec2)
371 	RECHEADER *rec1, *rec2;
372 {
373 	int r;
374 	u_char *pos1, *pos2, *end;
375 	u_char *cwts;
376 	for (cwts = wts; cwts; cwts = (cwts == wts1 ? NULL : wts1)) {
377 		pos1 = rec1->data;
378 		pos2 = rec2->data;
379 		if (!SINGL_FLD && (UNIQUE || stable_sort))
380 			end = pos1 + min(rec1->offset, rec2->offset);
381 		else
382 			end = pos1 + min(rec1->length, rec2->length);
383 
384 		for (; pos1 < end; ) {
385 			if ((r = cwts[*pos1++] - cwts[*pos2++]))
386 				return (r);
387 		}
388 	}
389 	return (0);
390 }
391