xref: /netbsd/usr.bin/sort/msort.c (revision 6550d01e)
1 /*	$NetBSD: msort.c,v 1.30 2010/02/05 21:58:42 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 #include "sort.h"
65 #include "fsort.h"
66 
67 __RCSID("$NetBSD: msort.c,v 1.30 2010/02/05 21:58:42 enami Exp $");
68 
69 #include <stdlib.h>
70 #include <string.h>
71 #include <unistd.h>
72 #include <util.h>
73 
74 /* Subroutines using comparisons: merge sort and check order */
75 #define DELETE (1)
76 
77 typedef struct mfile {
78 	FILE         *fp;
79 	get_func_t   get;
80 	RECHEADER    *rec;
81 	u_char       *end;
82 } MFILE;
83 
84 static int cmp(RECHEADER *, RECHEADER *);
85 static int insert(struct mfile **, struct mfile *, int, int);
86 static void merge_sort_fstack(FILE *, put_func_t, struct field *);
87 
88 /*
89  * Number of files merge() can merge in one pass.
90  */
91 #define MERGE_FNUM      16
92 
93 static struct mfile fstack[MERGE_FNUM];
94 static struct mfile fstack_1[MERGE_FNUM];
95 static struct mfile fstack_2[MERGE_FNUM];
96 static int fstack_count, fstack_1_count, fstack_2_count;
97 
98 void
99 save_for_merge(FILE *fp, get_func_t get, struct field *ftbl)
100 {
101 	FILE *mfp, *mfp1, *mfp2;
102 
103 	if (fstack_count == MERGE_FNUM) {
104 		/* Must reduce the number of temporary files */
105 		mfp = ftmp();
106 		merge_sort_fstack(mfp, putrec, ftbl);
107 		/* Save output in next layer */
108 		if (fstack_1_count == MERGE_FNUM) {
109 			mfp1 = ftmp();
110 			memcpy(fstack, fstack_1, sizeof fstack);
111 			merge_sort_fstack(mfp1, putrec, ftbl);
112 			if (fstack_2_count == MERGE_FNUM) {
113 				/* More than 4096 files! */
114 				mfp2 = ftmp();
115 				memcpy(fstack, fstack_2, sizeof fstack);
116 				merge_sort_fstack(mfp2, putrec, ftbl);
117 				fstack_2[0].fp = mfp2;
118 				fstack_2_count = 1;
119 			}
120 			fstack_2[fstack_2_count].fp = mfp1;
121 			fstack_2[fstack_2_count].get = geteasy;
122 			fstack_2_count++;
123 			fstack_1_count = 0;
124 		}
125 		fstack_1[fstack_1_count].fp = mfp;
126 		fstack_1[fstack_1_count].get = geteasy;
127 		fstack_1_count++;
128 		fstack_count = 0;
129 	}
130 
131 	fstack[fstack_count].fp = fp;
132 	fstack[fstack_count++].get = get;
133 }
134 
135 void
136 fmerge(struct filelist *filelist, int nfiles, FILE *outfp, struct field *ftbl)
137 {
138 	get_func_t get = SINGL_FLD ? makeline : makekey;
139 	FILE *fp;
140 	int i;
141 
142 	for (i = 0; i < nfiles; i++) {
143 		fp = fopen(filelist->names[i], "r");
144 		if (fp == NULL)
145 			err(2, "%s", filelist->names[i]);
146 		save_for_merge(fp, get, ftbl);
147 	}
148 
149 	merge_sort(outfp, putline, ftbl);
150 }
151 
152 void
153 merge_sort(FILE *outfp, put_func_t put, struct field *ftbl)
154 {
155 	int count = fstack_1_count + fstack_2_count;
156 	FILE *mfp;
157 	int i;
158 
159 	if (count == 0) {
160 		/* All files in initial array */
161 		merge_sort_fstack(outfp, put, ftbl);
162 		return;
163 	}
164 
165 	count += fstack_count;
166 
167 	/* Too many files for one merge sort */
168 	for (;;) {
169 		/* Sort latest 16 files */
170 		i = count;
171 		if (i > MERGE_FNUM)
172 			i = MERGE_FNUM;
173 		while (fstack_count > 0)
174 			fstack[--i] = fstack[--fstack_count];
175 		while (i > 0 && fstack_1_count > 0)
176 			fstack[--i] = fstack_1[--fstack_1_count];
177 		while (i > 0)
178 			fstack[--i] = fstack_2[--fstack_2_count];
179 		if (count <= MERGE_FNUM) {
180 			/* Got all the data */
181 			fstack_count = count;
182 			merge_sort_fstack(outfp, put, ftbl);
183 			return;
184 		}
185 		mfp = ftmp();
186 		fstack_count = count > MERGE_FNUM ? MERGE_FNUM : count;
187 		merge_sort_fstack(mfp, putrec, ftbl);
188 		fstack[0].fp = mfp;
189 		fstack[0].get = geteasy;
190 		fstack_count = 1;
191 		count -= MERGE_FNUM - 1;
192 	}
193 }
194 
195 static void
196 merge_sort_fstack(FILE *outfp, put_func_t put, struct field *ftbl)
197 {
198 	struct mfile *flistb[MERGE_FNUM], **flist = flistb, *cfile;
199 	RECHEADER *new_rec;
200 	u_char *new_end;
201 	void *tmp;
202 	int c, i, nfiles;
203 	size_t sz;
204 
205 	/* Read one record from each file (read again if a duplicate) */
206 	for (nfiles = i = 0; i < fstack_count; i++) {
207 		cfile = &fstack[i];
208 		if (cfile->rec == NULL) {
209 			cfile->rec = allocrec(NULL, DEFLLEN);
210 			cfile->end = (u_char *)cfile->rec + DEFLLEN;
211 		}
212 		rewind(cfile->fp);
213 
214 		for (;;) {
215 			c = cfile->get(cfile->fp, cfile->rec, cfile->end, ftbl);
216 			if (c == EOF)
217 				break;
218 
219 			if (c == BUFFEND) {
220 				/* Double buffer size */
221 				sz = (cfile->end - (u_char *)cfile->rec) * 2;
222 				cfile->rec = allocrec(cfile->rec, sz);
223 				cfile->end = (u_char *)cfile->rec + sz;
224 				continue;
225 			}
226 
227 			if (nfiles != 0) {
228 				if (insert(flist, cfile, nfiles, !DELETE))
229 					/* Duplicate removed */
230 					continue;
231 			} else
232 				flist[0] = cfile;
233 			nfiles++;
234 			break;
235 		}
236 	}
237 
238 	if (nfiles == 0)
239 		return;
240 
241 	/*
242 	 * We now loop reading a new record from the file with the
243 	 * 'sorted first' existing record.
244 	 * As each record is added, the 'first' record is written to the
245 	 * output file - maintaining one record from each file in the sorted
246 	 * list.
247 	 */
248 	new_rec = allocrec(NULL, DEFLLEN);
249 	new_end = (u_char *)new_rec + DEFLLEN;
250 	for (;;) {
251 		cfile = flist[0];
252 		c = cfile->get(cfile->fp, new_rec, new_end, ftbl);
253 		if (c == EOF) {
254 			/* Write out last record from now-empty input */
255 			put(cfile->rec, outfp);
256 			if (--nfiles == 0)
257 				break;
258 			/* Replace from file with now-first sorted record. */
259 			/* (Moving base 'flist' saves copying everything!) */
260 			flist++;
261 			continue;
262 		}
263 		if (c == BUFFEND) {
264 			/* Buffer not large enough - double in size */
265 			sz = (new_end - (u_char *)new_rec) * 2;
266 			new_rec = allocrec(new_rec, sz);
267 			new_end = (u_char *)new_rec +sz;
268 			continue;
269 		}
270 
271 		/* Swap in new buffer, saving old */
272 		tmp = cfile->rec;
273 		cfile->rec = new_rec;
274 		new_rec = tmp;
275 		tmp = cfile->end;
276 		cfile->end = new_end;
277 		new_end = tmp;
278 
279 		/* Add into sort, removing the original first entry */
280 		c = insert(flist, cfile, nfiles, DELETE);
281 		if (c != 0 || (UNIQUE && cfile == flist[0]
282 			    && cmp(new_rec, cfile->rec) == 0)) {
283 			/* Was an unwanted duplicate, restore buffer */
284 			tmp = cfile->rec;
285 			cfile->rec = new_rec;
286 			new_rec = tmp;
287 			tmp = cfile->end;
288 			cfile->end = new_end;
289 			new_end = tmp;
290 			continue;
291 		}
292 
293 		/* Write out 'old' record */
294 		put(new_rec, outfp);
295 	}
296 
297 	free(new_rec);
298 }
299 
300 /*
301  * if delete: inserts rec in flist, deletes flist[0];
302  * otherwise just inserts *rec in flist.
303  * Returns 1 if record is a duplicate to be ignored.
304  */
305 static int
306 insert(struct mfile **flist, struct mfile *rec, int ttop, int delete)
307 {
308 	int mid, top = ttop, bot = 0, cmpv = 1;
309 
310 	for (mid = top / 2; bot + 1 != top; mid = (bot + top) / 2) {
311 		cmpv = cmp(rec->rec, flist[mid]->rec);
312 		if (cmpv == 0 ) {
313 			if (UNIQUE)
314 				/* Duplicate key, read another record */
315 				/* NB: This doesn't guarantee to keep any
316 				 * particular record. */
317 				return 1;
318 			/*
319 			 * Apply sort by input file order.
320 			 * We could truncate the sort is the fileno are
321 			 * adjacent - but that is all too hard!
322 			 * The fileno cannot be equal, since we only have one
323 			 * record from each file (+ flist[0] which never
324 			 * comes here).
325 			 */
326 			cmpv = rec < flist[mid] ? -1 : 1;
327 			if (REVERSE)
328 				cmpv = -cmpv;
329 		}
330 		if (cmpv < 0)
331 			top = mid;
332 		else
333 			bot = mid;
334 	}
335 
336 	/* At this point we haven't yet compared against flist[0] */
337 
338 	if (delete) {
339 		/* flist[0] is ourselves, only the caller knows the old data */
340 		if (bot != 0) {
341 			memmove(flist, flist + 1, bot * sizeof(MFILE *));
342 			flist[bot] = rec;
343 		}
344 		return 0;
345 	}
346 
347 	/* Inserting original set of records */
348 
349 	if (bot == 0 && cmpv != 0) {
350 		/* Doesn't match flist[1], must compare with flist[0] */
351 		cmpv = cmp(rec->rec, flist[0]->rec);
352 		if (cmpv == 0 && UNIQUE)
353 			return 1;
354 		/* Add matching keys in file order (ie new is later) */
355 		if (cmpv < 0)
356 			bot = -1;
357 	}
358 	bot++;
359 	memmove(flist + bot + 1, flist + bot, (ttop - bot) * sizeof(MFILE *));
360 	flist[bot] = rec;
361 	return 0;
362 }
363 
364 /*
365  * check order on one file
366  */
367 void
368 order(struct filelist *filelist, struct field *ftbl)
369 {
370 	get_func_t get = SINGL_FLD ? makeline : makekey;
371 	RECHEADER *crec, *prec, *trec;
372 	u_char *crec_end, *prec_end, *trec_end;
373 	FILE *fp;
374 	int c;
375 
376 	fp = fopen(filelist->names[0], "r");
377 	if (fp == NULL)
378 		err(2, "%s", filelist->names[0]);
379 
380 	crec = malloc(offsetof(RECHEADER, data[DEFLLEN]));
381 	crec_end = crec->data + DEFLLEN;
382 	prec = malloc(offsetof(RECHEADER, data[DEFLLEN]));
383 	prec_end = prec->data + DEFLLEN;
384 
385 	/* XXX this does exit(0) for overlong lines */
386 	if (get(fp, prec, prec_end, ftbl) != 0)
387 		exit(0);
388 	while (get(fp, crec, crec_end, ftbl) == 0) {
389 		if (0 < (c = cmp(prec, crec))) {
390 			crec->data[crec->length-1] = 0;
391 			errx(1, "found disorder: %s", crec->data+crec->offset);
392 		}
393 		if (UNIQUE && !c) {
394 			crec->data[crec->length-1] = 0;
395 			errx(1, "found non-uniqueness: %s",
396 			    crec->data+crec->offset);
397 		}
398 		/*
399 		 * Swap pointers so that this record is on place pointed
400 		 * to by prec and new record is read to place pointed to by
401 		 * crec.
402 		 */
403 		trec = prec;
404 		prec = crec;
405 		crec = trec;
406 		trec_end = prec_end;
407 		prec_end = crec_end;
408 		crec_end = trec_end;
409 	}
410 	exit(0);
411 }
412 
413 static int
414 cmp(RECHEADER *rec1, RECHEADER *rec2)
415 {
416 	int len;
417 	int r;
418 
419 	/* key is weights */
420 	len = min(rec1->keylen, rec2->keylen);
421 	r = memcmp(rec1->data, rec2->data, len);
422 	if (r == 0)
423 		r = rec1->keylen - rec2->keylen;
424 	if (REVERSE)
425 		r = -r;
426 	return r;
427 }
428