xref: /freebsd/usr.bin/sort/file.c (revision f05cddf9)
1 /*-
2  * Copyright (C) 2009 Gabor Kovesdan <gabor@FreeBSD.org>
3  * Copyright (C) 2012 Oleg Moskalenko <mom040267@gmail.com>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/mman.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <sys/queue.h>
35 
36 #include <err.h>
37 #include <fcntl.h>
38 #if defined(SORT_THREADS)
39 #include <pthread.h>
40 #endif
41 #include <semaphore.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <wchar.h>
47 #include <wctype.h>
48 
49 #include "coll.h"
50 #include "file.h"
51 #include "radixsort.h"
52 
53 unsigned long long free_memory = 1000000;
54 unsigned long long available_free_memory = 1000000;
55 
56 bool use_mmap;
57 
58 const char *tmpdir = "/var/tmp";
59 const char *compress_program;
60 
61 size_t max_open_files = 16;
62 
63 /*
64  * How much space we read from file at once
65  */
66 #define READ_CHUNK (4096)
67 
68 /*
69  * File reader structure
70  */
71 struct file_reader
72 {
73 	struct reader_buffer	 rb;
74 	FILE			*file;
75 	char			*fname;
76 	unsigned char		*buffer;
77 	unsigned char		*mmapaddr;
78 	unsigned char		*mmapptr;
79 	size_t			 bsz;
80 	size_t			 cbsz;
81 	size_t			 mmapsize;
82 	size_t			 strbeg;
83 	int			 fd;
84 	char			 elsymb;
85 };
86 
87 /*
88  * Structure to be used in file merge process.
89  */
90 struct file_header
91 {
92 	struct file_reader		*fr;
93 	struct sort_list_item		*si; /* current top line */
94 	size_t				 file_pos;
95 };
96 
97 /*
98  * List elements of "cleanable" files list.
99  */
100 struct CLEANABLE_FILE
101 {
102 	char				*fn;
103 	LIST_ENTRY(CLEANABLE_FILE)	 files;
104 };
105 
106 /*
107  * List header of "cleanable" files list.
108  */
109 static LIST_HEAD(CLEANABLE_FILES,CLEANABLE_FILE) tmp_files;
110 
111 /*
112  * Semaphore to protect the tmp file list.
113  * We use semaphore here because it is signal-safe, according to POSIX.
114  * And semaphore does not require pthread library.
115  */
116 static sem_t tmp_files_sem;
117 
118 static void mt_sort(struct sort_list *list,
119     int (*sort_func)(void *, size_t, size_t,
120     int (*)(const void *, const void *)), const char* fn);
121 
122 /*
123  * Init tmp files list
124  */
125 void
126 init_tmp_files(void)
127 {
128 
129 	LIST_INIT(&tmp_files);
130 	sem_init(&tmp_files_sem, 0, 1);
131 }
132 
133 /*
134  * Save name of a tmp file for signal cleanup
135  */
136 void
137 tmp_file_atexit(const char *tmp_file)
138 {
139 
140 	if (tmp_file) {
141 		sem_wait(&tmp_files_sem);
142 		struct CLEANABLE_FILE *item =
143 		    sort_malloc(sizeof(struct CLEANABLE_FILE));
144 		item->fn = sort_strdup(tmp_file);
145 		LIST_INSERT_HEAD(&tmp_files, item, files);
146 		sem_post(&tmp_files_sem);
147 	}
148 }
149 
150 /*
151  * Clear tmp files
152  */
153 void
154 clear_tmp_files(void)
155 {
156 	struct CLEANABLE_FILE *item;
157 
158 	sem_wait(&tmp_files_sem);
159 	LIST_FOREACH(item,&tmp_files,files) {
160 		if ((item) && (item->fn))
161 			unlink(item->fn);
162 	}
163 	sem_post(&tmp_files_sem);
164 }
165 
166 /*
167  * Check whether a file is a temporary file
168  */
169 static bool
170 file_is_tmp(const char* fn)
171 {
172 	struct CLEANABLE_FILE *item;
173 	bool ret = false;
174 
175 	if (fn) {
176 		sem_wait(&tmp_files_sem);
177 		LIST_FOREACH(item,&tmp_files,files) {
178 			if ((item) && (item->fn))
179 				if (strcmp(item->fn, fn) == 0) {
180 					ret = true;
181 					break;
182 				}
183 		}
184 		sem_post(&tmp_files_sem);
185 	}
186 
187 	return (ret);
188 }
189 
190 /*
191  * Read zero-terminated line from a file
192  */
193 char *
194 read_file0_line(struct file0_reader *f0r)
195 {
196 	size_t pos = 0;
197 	int c;
198 
199 	if ((f0r->f == NULL) || feof(f0r->f))
200 		return (NULL);
201 
202 	if (f0r->current_line && f0r->current_sz > 0)
203 		f0r->current_line[0] = 0;
204 
205 	while (!feof(f0r->f)) {
206 		c = fgetc(f0r->f);
207 		if (feof(f0r->f) || (c == -1))
208 			break;
209 		if ((pos + 1) >= f0r->current_sz) {
210 			size_t newsz = (f0r->current_sz + 2) * 2;
211 			f0r->current_line = sort_realloc(f0r->current_line,
212 			    newsz);
213 			f0r->current_sz = newsz;
214 		}
215 		f0r->current_line[pos] = (char)c;
216 		if (c == 0)
217 			break;
218 		else
219 			f0r->current_line[pos + 1] = 0;
220 		++pos;
221 	}
222 
223 	return f0r->current_line;
224 }
225 
226 /*
227  * Generate new temporary file name
228  */
229 char *
230 new_tmp_file_name(void)
231 {
232 	static size_t tfcounter = 0;
233 	static const char *fn = ".bsdsort.";
234 	char *ret;
235 	size_t sz;
236 
237 	sz = strlen(tmpdir) + 1 + strlen(fn) + 32 + 1;
238 	ret = sort_malloc(sz);
239 
240 	sprintf(ret, "%s/%s%d.%lu", tmpdir, fn, (int) getpid(), (unsigned long)(tfcounter++));
241 	tmp_file_atexit(ret);
242 	return (ret);
243 }
244 
245 /*
246  * Initialize file list
247  */
248 void
249 file_list_init(struct file_list *fl, bool tmp)
250 {
251 
252 	if (fl) {
253 		fl->count = 0;
254 		fl->sz = 0;
255 		fl->fns = NULL;
256 		fl->tmp = tmp;
257 	}
258 }
259 
260 /*
261  * Add a file name to the list
262  */
263 void
264 file_list_add(struct file_list *fl, char *fn, bool allocate)
265 {
266 
267 	if (fl && fn) {
268 		if (fl->count >= fl->sz || (fl->fns == NULL)) {
269 			fl->sz = (fl->sz) * 2 + 1;
270 			fl->fns = sort_realloc(fl->fns, fl->sz *
271 			    sizeof(char *));
272 		}
273 		fl->fns[fl->count] = allocate ? sort_strdup(fn) : fn;
274 		fl->count += 1;
275 	}
276 }
277 
278 /*
279  * Populate file list from array of file names
280  */
281 void
282 file_list_populate(struct file_list *fl, int argc, char **argv, bool allocate)
283 {
284 
285 	if (fl && argv) {
286 		int i;
287 
288 		for (i = 0; i < argc; i++)
289 			file_list_add(fl, argv[i], allocate);
290 	}
291 }
292 
293 /*
294  * Clean file list data and delete the files,
295  * if this is a list of temporary files
296  */
297 void
298 file_list_clean(struct file_list *fl)
299 {
300 
301 	if (fl) {
302 		if (fl->fns) {
303 			size_t i;
304 
305 			for (i = 0; i < fl->count; i++) {
306 				if (fl->fns[i]) {
307 					if (fl->tmp)
308 						unlink(fl->fns[i]);
309 					sort_free(fl->fns[i]);
310 					fl->fns[i] = 0;
311 				}
312 			}
313 			sort_free(fl->fns);
314 			fl->fns = NULL;
315 		}
316 		fl->sz = 0;
317 		fl->count = 0;
318 		fl->tmp = false;
319 	}
320 }
321 
322 /*
323  * Init sort list
324  */
325 void
326 sort_list_init(struct sort_list *l)
327 {
328 
329 	if (l) {
330 		l->count = 0;
331 		l->size = 0;
332 		l->memsize = sizeof(struct sort_list);
333 		l->list = NULL;
334 	}
335 }
336 
337 /*
338  * Add string to sort list
339  */
340 void
341 sort_list_add(struct sort_list *l, struct bwstring *str)
342 {
343 
344 	if (l && str) {
345 		size_t indx = l->count;
346 
347 		if ((l->list == NULL) || (indx >= l->size)) {
348 			size_t newsize = (l->size + 1) + 1024;
349 
350 			l->list = sort_realloc(l->list,
351 			    sizeof(struct sort_list_item*) * newsize);
352 			l->memsize += (newsize - l->size) *
353 			    sizeof(struct sort_list_item*);
354 			l->size = newsize;
355 		}
356 		l->list[indx] = sort_list_item_alloc();
357 		sort_list_item_set(l->list[indx], str);
358 		l->memsize += sort_list_item_size(l->list[indx]);
359 		l->count += 1;
360 	}
361 }
362 
363 /*
364  * Clean sort list data
365  */
366 void
367 sort_list_clean(struct sort_list *l)
368 {
369 
370 	if (l) {
371 		if (l->list) {
372 			size_t i;
373 
374 			for (i = 0; i < l->count; i++) {
375 				struct sort_list_item *item;
376 
377 				item = l->list[i];
378 
379 				if (item) {
380 					sort_list_item_clean(item);
381 					sort_free(item);
382 					l->list[i] = NULL;
383 				}
384 			}
385 			sort_free(l->list);
386 			l->list = NULL;
387 		}
388 		l->count = 0;
389 		l->size = 0;
390 		l->memsize = sizeof(struct sort_list);
391 	}
392 }
393 
394 /*
395  * Write sort list to file
396  */
397 void
398 sort_list_dump(struct sort_list *l, const char *fn)
399 {
400 
401 	if (l && fn) {
402 		FILE *f;
403 
404 		f = openfile(fn, "w");
405 		if (f == NULL)
406 			err(2, NULL);
407 
408 		if (l->list) {
409 			size_t i;
410 			if (!(sort_opts_vals.uflag)) {
411 				for (i = 0; i < l->count; ++i)
412 					bwsfwrite(l->list[i]->str, f,
413 					    sort_opts_vals.zflag);
414 			} else {
415 				struct sort_list_item *last_printed_item = NULL;
416 				struct sort_list_item *item;
417 				for (i = 0; i < l->count; ++i) {
418 					item = l->list[i];
419 					if ((last_printed_item == NULL) ||
420 					    list_coll(&last_printed_item, &item)) {
421 						bwsfwrite(item->str, f, sort_opts_vals.zflag);
422 						last_printed_item = item;
423 					}
424 				}
425 			}
426 		}
427 
428 		closefile(f, fn);
429 	}
430 }
431 
432 /*
433  * Checks if the given file is sorted.  Stops at the first disorder,
434  * prints the disordered line and returns 1.
435  */
436 int
437 check(const char *fn)
438 {
439 	struct bwstring *s1, *s2, *s1disorder, *s2disorder;
440 	struct file_reader *fr;
441 	struct keys_array *ka1, *ka2;
442 	int res;
443 	size_t pos, posdisorder;
444 
445 	s1 = s2 = s1disorder = s2disorder = NULL;
446 	ka1 = ka2 = NULL;
447 
448 	fr = file_reader_init(fn);
449 
450 	res = 0;
451 	pos = 1;
452 	posdisorder = 1;
453 
454 	if (fr == NULL) {
455 		err(2, NULL);
456 		goto end;
457 	}
458 
459 	s1 = file_reader_readline(fr);
460 	if (s1 == NULL)
461 		goto end;
462 
463 	ka1 = keys_array_alloc();
464 	preproc(s1, ka1);
465 
466 	s2 = file_reader_readline(fr);
467 	if (s2 == NULL)
468 		goto end;
469 
470 	ka2 = keys_array_alloc();
471 	preproc(s2, ka2);
472 
473 	for (;;) {
474 
475 		if (debug_sort) {
476 			bwsprintf(stdout, s2, "s1=<", ">");
477 			bwsprintf(stdout, s1, "s2=<", ">");
478 		}
479 		int cmp = key_coll(ka2, ka1, 0);
480 		if (debug_sort)
481 			printf("; cmp1=%d", cmp);
482 
483 		if (!cmp && sort_opts_vals.complex_sort &&
484 		    !(sort_opts_vals.uflag) && !(sort_opts_vals.sflag)) {
485 			cmp = top_level_str_coll(s2, s1);
486 			if (debug_sort)
487 				printf("; cmp2=%d", cmp);
488 		}
489 		if (debug_sort)
490 			printf("\n");
491 
492 		if ((sort_opts_vals.uflag && (cmp <= 0)) || (cmp < 0)) {
493 			if (!(sort_opts_vals.csilentflag)) {
494 				s2disorder = bwsdup(s2);
495 				posdisorder = pos;
496 				if (debug_sort)
497 					s1disorder = bwsdup(s1);
498 			}
499 			res = 1;
500 			goto end;
501 		}
502 
503 		pos++;
504 
505 		clean_keys_array(s1, ka1);
506 		sort_free(ka1);
507 		ka1 = ka2;
508 		ka2 = NULL;
509 
510 		bwsfree(s1);
511 		s1 = s2;
512 
513 		s2 = file_reader_readline(fr);
514 		if (s2 == NULL)
515 			goto end;
516 
517 		ka2 = keys_array_alloc();
518 		preproc(s2, ka2);
519 	}
520 
521 end:
522 	if (ka1) {
523 		clean_keys_array(s1, ka1);
524 		sort_free(ka1);
525 	}
526 
527 	if (s1)
528 		bwsfree(s1);
529 
530 	if (ka2) {
531 		clean_keys_array(s2, ka2);
532 		sort_free(ka2);
533 	}
534 
535 	if (s2)
536 		bwsfree(s2);
537 
538 	if ((fn == NULL) || (*fn == 0) || (strcmp(fn, "-") == 0)) {
539 		for (;;) {
540 			s2 = file_reader_readline(fr);
541 			if (s2 == NULL)
542 				break;
543 			bwsfree(s2);
544 		}
545 	}
546 
547 	file_reader_free(fr);
548 
549 	if (s2disorder) {
550 		bws_disorder_warnx(s2disorder, fn, posdisorder);
551 		if (s1disorder) {
552 			bws_disorder_warnx(s1disorder, fn, posdisorder);
553 			if (s1disorder != s2disorder)
554 				bwsfree(s1disorder);
555 		}
556 		bwsfree(s2disorder);
557 		s1disorder = NULL;
558 		s2disorder = NULL;
559 	}
560 
561 	if (res)
562 		exit(res);
563 
564 	return (0);
565 }
566 
567 /*
568  * Opens a file.  If the given filename is "-", stdout will be
569  * opened.
570  */
571 FILE *
572 openfile(const char *fn, const char *mode)
573 {
574 	FILE *file;
575 
576 	if (strcmp(fn, "-") == 0) {
577 		return ((mode && mode[0] == 'r') ? stdin : stdout);
578 	} else {
579 		mode_t orig_file_mask = 0;
580 		int is_tmp = file_is_tmp(fn);
581 
582 		if (is_tmp && (mode[0] == 'w'))
583 			orig_file_mask = umask(S_IWGRP | S_IWOTH |
584 			    S_IRGRP | S_IROTH);
585 
586 		if (is_tmp && (compress_program != NULL)) {
587 			char *cmd;
588 			size_t cmdsz;
589 
590 			cmdsz = strlen(fn) + 128;
591 			cmd = sort_malloc(cmdsz);
592 
593 			fflush(stdout);
594 
595 			if (mode[0] == 'r')
596 				snprintf(cmd, cmdsz - 1, "cat %s | %s -d",
597 				    fn, compress_program);
598 			else if (mode[0] == 'w')
599 				snprintf(cmd, cmdsz - 1, "%s > %s",
600 				    compress_program, fn);
601 			else
602 				err(2, "%s", getstr(7));
603 
604 			if ((file = popen(cmd, mode)) == NULL)
605 				err(2, NULL);
606 
607 			sort_free(cmd);
608 
609 		} else
610 			if ((file = fopen(fn, mode)) == NULL)
611 				err(2, NULL);
612 
613 		if (is_tmp && (mode[0] == 'w'))
614 			umask(orig_file_mask);
615 	}
616 
617 	return (file);
618 }
619 
620 /*
621  * Close file
622  */
623 void
624 closefile(FILE *f, const char *fn)
625 {
626 	if (f == NULL) {
627 		;
628 	} else if (f == stdin) {
629 		;
630 	} else if (f == stdout) {
631 		fflush(f);
632 	} else {
633 		if (file_is_tmp(fn) && compress_program != NULL) {
634 			if(pclose(f)<0)
635 				err(2,NULL);
636 		} else
637 			fclose(f);
638 	}
639 }
640 
641 /*
642  * Reads a file into the internal buffer.
643  */
644 struct file_reader *
645 file_reader_init(const char *fsrc)
646 {
647 	struct file_reader *ret;
648 
649 	if (fsrc == NULL)
650 		fsrc = "-";
651 
652 	ret = sort_malloc(sizeof(struct file_reader));
653 	memset(ret, 0, sizeof(struct file_reader));
654 
655 	ret->elsymb = '\n';
656 	if (sort_opts_vals.zflag)
657 		ret->elsymb = 0;
658 
659 	ret->fname = sort_strdup(fsrc);
660 
661 	if (strcmp(fsrc, "-") && (compress_program == NULL) && use_mmap) {
662 
663 		do {
664 			struct stat stat_buf;
665 			void *addr;
666 			size_t sz = 0;
667 			int fd, flags;
668 
669 			flags = MAP_NOCORE | MAP_NOSYNC;
670 			addr = MAP_FAILED;
671 
672 			fd = open(fsrc, O_RDONLY);
673 			if (fd < 0)
674 				err(2, NULL);
675 
676 			if (fstat(fd, &stat_buf) < 0) {
677 				close(fd);
678 				break;
679 			}
680 
681 			sz = stat_buf.st_size;
682 
683 #if defined(MAP_PREFAULT_READ)
684 			flags |= MAP_PREFAULT_READ;
685 #endif
686 
687 			addr = mmap(NULL, sz, PROT_READ, flags, fd, 0);
688 			if (addr == MAP_FAILED) {
689 				close(fd);
690 				break;
691 			}
692 
693 			ret->fd = fd;
694 			ret->mmapaddr = addr;
695 			ret->mmapsize = sz;
696 			ret->mmapptr = ret->mmapaddr;
697 
698 		} while (0);
699 	}
700 
701 	if (ret->mmapaddr == NULL) {
702 		ret->file = openfile(fsrc, "r");
703 		if (ret->file == NULL)
704 			err(2, NULL);
705 
706 		if (strcmp(fsrc, "-")) {
707 			ret->cbsz = READ_CHUNK;
708 			ret->buffer = sort_malloc(ret->cbsz);
709 			ret->bsz = 0;
710 			ret->strbeg = 0;
711 
712 			ret->bsz = fread(ret->buffer, 1, ret->cbsz, ret->file);
713 			if (ret->bsz == 0) {
714 				if (ferror(ret->file))
715 					err(2, NULL);
716 			}
717 		}
718 	}
719 
720 	return (ret);
721 }
722 
723 struct bwstring *
724 file_reader_readline(struct file_reader *fr)
725 {
726 	struct bwstring *ret = NULL;
727 
728 	if (fr->mmapaddr) {
729 		unsigned char *mmapend;
730 
731 		mmapend = fr->mmapaddr + fr->mmapsize;
732 		if (fr->mmapptr >= mmapend)
733 			return (NULL);
734 		else {
735 			unsigned char *strend;
736 			size_t sz;
737 
738 			sz = mmapend - fr->mmapptr;
739 			strend = memchr(fr->mmapptr, fr->elsymb, sz);
740 
741 			if (strend == NULL) {
742 				ret = bwscsbdup(fr->mmapptr, sz);
743 				fr->mmapptr = mmapend;
744 			} else {
745 				ret = bwscsbdup(fr->mmapptr, strend -
746 				    fr->mmapptr);
747 				fr->mmapptr = strend + 1;
748 			}
749 		}
750 
751 	} else if (fr->file != stdin) {
752 		unsigned char *strend;
753 		size_t bsz1, remsz, search_start;
754 
755 		search_start = 0;
756 		remsz = 0;
757 		strend = NULL;
758 
759 		if (fr->bsz > fr->strbeg)
760 			remsz = fr->bsz - fr->strbeg;
761 
762 		/* line read cycle */
763 		for (;;) {
764 			if (remsz > search_start)
765 				strend = memchr(fr->buffer + fr->strbeg +
766 				    search_start, fr->elsymb, remsz -
767 				    search_start);
768 			else
769 				strend = NULL;
770 
771 			if (strend)
772 				break;
773 			if (feof(fr->file))
774 				break;
775 
776 			if (fr->bsz != fr->cbsz)
777 				/* NOTREACHED */
778 				err(2, "File read software error 1");
779 
780 			if (remsz > (READ_CHUNK >> 1)) {
781 				search_start = fr->cbsz - fr->strbeg;
782 				fr->cbsz += READ_CHUNK;
783 				fr->buffer = sort_realloc(fr->buffer,
784 				    fr->cbsz);
785 				bsz1 = fread(fr->buffer + fr->bsz, 1,
786 				    READ_CHUNK, fr->file);
787 				if (bsz1 == 0) {
788 					if (ferror(fr->file))
789 						err(2, NULL);
790 					break;
791 				}
792 				fr->bsz += bsz1;
793 				remsz += bsz1;
794 			} else {
795 				if (remsz > 0 && fr->strbeg>0)
796 					bcopy(fr->buffer + fr->strbeg,
797 					    fr->buffer, remsz);
798 
799 				fr->strbeg = 0;
800 				search_start = remsz;
801 				bsz1 = fread(fr->buffer + remsz, 1,
802 				    fr->cbsz - remsz, fr->file);
803 				if (bsz1 == 0) {
804 					if (ferror(fr->file))
805 						err(2, NULL);
806 					break;
807 				}
808 				fr->bsz = remsz + bsz1;
809 				remsz = fr->bsz;
810 			}
811 		}
812 
813 		if (strend == NULL)
814 			strend = fr->buffer + fr->bsz;
815 
816 		if ((fr->buffer + fr->strbeg <= strend) &&
817 		    (fr->strbeg < fr->bsz) && (remsz>0))
818 			ret = bwscsbdup(fr->buffer + fr->strbeg, strend -
819 			    fr->buffer - fr->strbeg);
820 
821 		fr->strbeg = (strend - fr->buffer) + 1;
822 
823 	} else {
824 		size_t len = 0;
825 
826 		ret = bwsfgetln(fr->file, &len, sort_opts_vals.zflag,
827 		    &(fr->rb));
828 	}
829 
830 	return (ret);
831 }
832 
833 static void
834 file_reader_clean(struct file_reader *fr)
835 {
836 
837 	if (fr) {
838 		if (fr->mmapaddr)
839 			munmap(fr->mmapaddr, fr->mmapsize);
840 
841 		if (fr->fd)
842 			close(fr->fd);
843 
844 		if (fr->buffer)
845 			sort_free(fr->buffer);
846 
847 		if (fr->file)
848 			if (fr->file != stdin)
849 				closefile(fr->file, fr->fname);
850 
851 		if(fr->fname)
852 			sort_free(fr->fname);
853 
854 		memset(fr, 0, sizeof(struct file_reader));
855 	}
856 }
857 
858 void
859 file_reader_free(struct file_reader *fr)
860 {
861 
862 	if (fr) {
863 		file_reader_clean(fr);
864 		sort_free(fr);
865 	}
866 }
867 
868 int
869 procfile(const char *fsrc, struct sort_list *list, struct file_list *fl)
870 {
871 	struct file_reader *fr;
872 
873 	fr = file_reader_init(fsrc);
874 	if (fr == NULL)
875 		err(2, NULL);
876 
877 	/* file browse cycle */
878 	for (;;) {
879 		struct bwstring *bws;
880 
881 		bws = file_reader_readline(fr);
882 
883 		if (bws == NULL)
884 			break;
885 
886 		sort_list_add(list, bws);
887 
888 		if (list->memsize >= available_free_memory) {
889 			char *fn;
890 
891 			fn = new_tmp_file_name();
892 			sort_list_to_file(list, fn);
893 			file_list_add(fl, fn, false);
894 			sort_list_clean(list);
895 		}
896 	}
897 
898 	file_reader_free(fr);
899 
900 	return (0);
901 }
902 
903 /*
904  * Compare file headers. Files with EOF always go to the end of the list.
905  */
906 static int
907 file_header_cmp(struct file_header *f1, struct file_header *f2)
908 {
909 
910 	if (f1 == f2)
911 		return (0);
912 	else {
913 		if (f1->fr == NULL) {
914 			return ((f2->fr == NULL) ? 0 : +1);
915 		} else if (f2->fr == NULL)
916 			return (-1);
917 		else {
918 			int ret;
919 
920 			ret = list_coll(&(f1->si), &(f2->si));
921 			if (!ret)
922 				return ((f1->file_pos < f2->file_pos) ? -1 : +1);
923 			return (ret);
924 		}
925 	}
926 }
927 
928 /*
929  * Allocate and init file header structure
930  */
931 static void
932 file_header_init(struct file_header **fh, const char *fn, size_t file_pos)
933 {
934 
935 	if (fh && fn) {
936 		struct bwstring *line;
937 
938 		*fh = sort_malloc(sizeof(struct file_header));
939 		(*fh)->file_pos = file_pos;
940 		(*fh)->fr = file_reader_init(fn);
941 		if ((*fh)->fr == NULL) {
942 			perror(fn);
943 			err(2, "%s", getstr(8));
944 		}
945 		line = file_reader_readline((*fh)->fr);
946 		if (line == NULL) {
947 			file_reader_free((*fh)->fr);
948 			(*fh)->fr = NULL;
949 			(*fh)->si = NULL;
950 		} else {
951 			(*fh)->si = sort_list_item_alloc();
952 			sort_list_item_set((*fh)->si, line);
953 		}
954 	}
955 }
956 
957 /*
958  * Close file
959  */
960 static void
961 file_header_close(struct file_header **fh)
962 {
963 
964 	if (fh && *fh) {
965 		if ((*fh)->fr) {
966 			file_reader_free((*fh)->fr);
967 			(*fh)->fr = NULL;
968 		}
969 		if ((*fh)->si) {
970 			sort_list_item_clean((*fh)->si);
971 			sort_free((*fh)->si);
972 			(*fh)->si = NULL;
973 		}
974 		sort_free(*fh);
975 		*fh = NULL;
976 	}
977 }
978 
979 /*
980  * Swap two array elements
981  */
982 static void
983 file_header_swap(struct file_header **fh, size_t i1, size_t i2)
984 {
985 	struct file_header *tmp;
986 
987 	tmp = fh[i1];
988 	fh[i1] = fh[i2];
989 	fh[i2] = tmp;
990 }
991 
992 /* heap algorithm ==>> */
993 
994 /*
995  * See heap sort algorithm
996  * "Raises" last element to its right place
997  */
998 static void
999 file_header_heap_swim(struct file_header **fh, size_t indx)
1000 {
1001 
1002 	if (indx > 0) {
1003 		size_t parent_index;
1004 
1005 		parent_index = (indx - 1) >> 1;
1006 
1007 		if (file_header_cmp(fh[indx], fh[parent_index]) < 0) {
1008 			/* swap child and parent and continue */
1009 			file_header_swap(fh, indx, parent_index);
1010 			file_header_heap_swim(fh, parent_index);
1011 		}
1012 	}
1013 }
1014 
1015 /*
1016  * Sink the top element to its correct position
1017  */
1018 static void
1019 file_header_heap_sink(struct file_header **fh, size_t indx, size_t size)
1020 {
1021 	size_t left_child_index;
1022 	size_t right_child_index;
1023 
1024 	left_child_index = indx + indx + 1;
1025 	right_child_index = left_child_index + 1;
1026 
1027 	if (left_child_index < size) {
1028 		size_t min_child_index;
1029 
1030 		min_child_index = left_child_index;
1031 
1032 		if ((right_child_index < size) &&
1033 		    (file_header_cmp(fh[left_child_index],
1034 		    fh[right_child_index]) > 0))
1035 			min_child_index = right_child_index;
1036 		if (file_header_cmp(fh[indx], fh[min_child_index]) > 0) {
1037 			file_header_swap(fh, indx, min_child_index);
1038 			file_header_heap_sink(fh, min_child_index, size);
1039 		}
1040 	}
1041 }
1042 
1043 /* <<== heap algorithm */
1044 
1045 /*
1046  * Adds element to the "left" end
1047  */
1048 static void
1049 file_header_list_rearrange_from_header(struct file_header **fh, size_t size)
1050 {
1051 
1052 	file_header_heap_sink(fh, 0, size);
1053 }
1054 
1055 /*
1056  * Adds element to the "right" end
1057  */
1058 static void
1059 file_header_list_push(struct file_header *f, struct file_header **fh, size_t size)
1060 {
1061 
1062 	fh[size++] = f;
1063 	file_header_heap_swim(fh, size - 1);
1064 }
1065 
1066 struct last_printed
1067 {
1068 	struct bwstring *str;
1069 };
1070 
1071 /*
1072  * Prints the current line of the file
1073  */
1074 static void
1075 file_header_print(struct file_header *fh, FILE *f_out, struct last_printed *lp)
1076 {
1077 
1078 	if (fh && fh->fr && f_out && fh->si && fh->si->str) {
1079 		if (sort_opts_vals.uflag) {
1080 			if ((lp->str == NULL) || (str_list_coll(lp->str, &(fh->si)))) {
1081 				bwsfwrite(fh->si->str, f_out, sort_opts_vals.zflag);
1082 				if (lp->str)
1083 					bwsfree(lp->str);
1084 				lp->str = bwsdup(fh->si->str);
1085 			}
1086 		} else
1087 			bwsfwrite(fh->si->str, f_out, sort_opts_vals.zflag);
1088 	}
1089 }
1090 
1091 /*
1092  * Read next line
1093  */
1094 static void
1095 file_header_read_next(struct file_header *fh)
1096 {
1097 
1098 	if (fh && fh->fr) {
1099 		struct bwstring *tmp;
1100 
1101 		tmp = file_reader_readline(fh->fr);
1102 		if (tmp == NULL) {
1103 			file_reader_free(fh->fr);
1104 			fh->fr = NULL;
1105 			if (fh->si) {
1106 				sort_list_item_clean(fh->si);
1107 				sort_free(fh->si);
1108 				fh->si = NULL;
1109 			}
1110 		} else {
1111 			if (fh->si == NULL)
1112 				fh->si = sort_list_item_alloc();
1113 			sort_list_item_set(fh->si, tmp);
1114 		}
1115 	}
1116 }
1117 
1118 /*
1119  * Merge array of "files headers"
1120  */
1121 static void
1122 file_headers_merge(size_t fnum, struct file_header **fh, FILE *f_out)
1123 {
1124 	struct last_printed lp;
1125 	size_t i;
1126 
1127 	memset(&lp, 0, sizeof(lp));
1128 
1129 	/*
1130 	 * construct the initial sort structure
1131 	 */
1132 	for (i = 0; i < fnum; i++)
1133 		file_header_list_push(fh[i], fh, i);
1134 
1135 	while (fh[0]->fr) { /* unfinished files are always in front */
1136 		/* output the smallest line: */
1137 		file_header_print(fh[0], f_out, &lp);
1138 		/* read a new line, if possible: */
1139 		file_header_read_next(fh[0]);
1140 		/* re-arrange the list: */
1141 		file_header_list_rearrange_from_header(fh, fnum);
1142 	}
1143 
1144 	if (lp.str)
1145 		bwsfree(lp.str);
1146 }
1147 
1148 /*
1149  * Merges the given files into the output file, which can be
1150  * stdout.
1151  */
1152 static void
1153 merge_files_array(size_t argc, char **argv, const char *fn_out)
1154 {
1155 
1156 	if (argv && fn_out) {
1157 		struct file_header **fh;
1158 		FILE *f_out;
1159 		size_t i;
1160 
1161 		f_out = openfile(fn_out, "w");
1162 
1163 		if (f_out == NULL)
1164 			err(2, NULL);
1165 
1166 		fh = sort_malloc((argc + 1) * sizeof(struct file_header *));
1167 
1168 		for (i = 0; i < argc; i++)
1169 			file_header_init(fh + i, argv[i], (size_t) i);
1170 
1171 		file_headers_merge(argc, fh, f_out);
1172 
1173 		for (i = 0; i < argc; i++)
1174 			file_header_close(fh + i);
1175 
1176 		sort_free(fh);
1177 
1178 		closefile(f_out, fn_out);
1179 	}
1180 }
1181 
1182 /*
1183  * Shrinks the file list until its size smaller than max number of opened files
1184  */
1185 static int
1186 shrink_file_list(struct file_list *fl)
1187 {
1188 
1189 	if ((fl == NULL) || (size_t) (fl->count) < max_open_files)
1190 		return (0);
1191 	else {
1192 		struct file_list new_fl;
1193 		size_t indx = 0;
1194 
1195 		file_list_init(&new_fl, true);
1196 		while (indx < fl->count) {
1197 			char *fnew;
1198 			size_t num;
1199 
1200 			num = fl->count - indx;
1201 			fnew = new_tmp_file_name();
1202 
1203 			if ((size_t) num >= max_open_files)
1204 				num = max_open_files - 1;
1205 			merge_files_array(num, fl->fns + indx, fnew);
1206 			if (fl->tmp) {
1207 				size_t i;
1208 
1209 				for (i = 0; i < num; i++)
1210 					unlink(fl->fns[indx + i]);
1211 			}
1212 			file_list_add(&new_fl, fnew, false);
1213 			indx += num;
1214 		}
1215 		fl->tmp = false; /* already taken care of */
1216 		file_list_clean(fl);
1217 
1218 		fl->count = new_fl.count;
1219 		fl->fns = new_fl.fns;
1220 		fl->sz = new_fl.sz;
1221 		fl->tmp = new_fl.tmp;
1222 
1223 		return (1);
1224 	}
1225 }
1226 
1227 /*
1228  * Merge list of files
1229  */
1230 void
1231 merge_files(struct file_list *fl, const char *fn_out)
1232 {
1233 
1234 	if (fl && fn_out) {
1235 		while (shrink_file_list(fl));
1236 
1237 		merge_files_array(fl->count, fl->fns, fn_out);
1238 	}
1239 }
1240 
1241 static const char *
1242 get_sort_method_name(int sm)
1243 {
1244 
1245 	if (sm == SORT_MERGESORT)
1246 		return "mergesort";
1247 	else if (sort_opts_vals.sort_method == SORT_RADIXSORT)
1248 		return "radixsort";
1249 	else if (sort_opts_vals.sort_method == SORT_HEAPSORT)
1250 		return "heapsort";
1251 	else
1252 		return "quicksort";
1253 }
1254 
1255 /*
1256  * Wrapper for qsort
1257  */
1258 static int sort_qsort(void *list, size_t count, size_t elem_size,
1259     int (*cmp_func)(const void *, const void *))
1260 {
1261 
1262 	qsort(list, count, elem_size, cmp_func);
1263 	return (0);
1264 }
1265 
1266 /*
1267  * Sort list of lines and writes it to the file
1268  */
1269 void
1270 sort_list_to_file(struct sort_list *list, const char *outfile)
1271 {
1272 	struct sort_mods *sm = &(keys[0].sm);
1273 
1274 	if (!(sm->Mflag) && !(sm->Rflag) && !(sm->Vflag) && !(sm->Vflag) &&
1275 	    !(sm->gflag) && !(sm->hflag) && !(sm->nflag)) {
1276 		if ((sort_opts_vals.sort_method == SORT_DEFAULT) && byte_sort)
1277 			sort_opts_vals.sort_method = SORT_RADIXSORT;
1278 
1279 	} else if (sort_opts_vals.sort_method == SORT_RADIXSORT)
1280 		err(2, "%s", getstr(9));
1281 
1282 	/*
1283 	 * to handle stable sort and the unique cases in the
1284 	 * right order, we need stable basic algorithm
1285 	 */
1286 	if (sort_opts_vals.sflag) {
1287 		switch (sort_opts_vals.sort_method){
1288 		case SORT_MERGESORT:
1289 			break;
1290 		case SORT_RADIXSORT:
1291 			break;
1292 		case SORT_DEFAULT:
1293 			sort_opts_vals.sort_method = SORT_MERGESORT;
1294 			break;
1295 		default:
1296 			errx(2, "%s", getstr(10));
1297 		};
1298 	}
1299 
1300 	if (sort_opts_vals.sort_method == SORT_DEFAULT)
1301 		sort_opts_vals.sort_method = DEFAULT_SORT_ALGORITHM;
1302 
1303 	if (debug_sort)
1304 		printf("sort_method=%s\n",
1305 		    get_sort_method_name(sort_opts_vals.sort_method));
1306 
1307 	switch (sort_opts_vals.sort_method){
1308 	case SORT_RADIXSORT:
1309 		rxsort(list->list, list->count);
1310 		sort_list_dump(list, outfile);
1311 		break;
1312 	case SORT_MERGESORT:
1313 		mt_sort(list, mergesort, outfile);
1314 		break;
1315 	case SORT_HEAPSORT:
1316 		mt_sort(list, heapsort,	outfile);
1317 		break;
1318 	case SORT_QSORT:
1319 		mt_sort(list, sort_qsort, outfile);
1320 		break;
1321 	default:
1322 		mt_sort(list, DEFAULT_SORT_FUNC, outfile);
1323 		break;
1324 	}
1325 }
1326 
1327 /******************* MT SORT ************************/
1328 
1329 #if defined(SORT_THREADS)
1330 /* semaphore to count threads */
1331 static sem_t mtsem;
1332 
1333 /* current system sort function */
1334 static int (*g_sort_func)(void *, size_t, size_t,
1335     int(*)(const void *, const void *));
1336 
1337 /*
1338  * Sort cycle thread (in multi-threaded mode)
1339  */
1340 static void*
1341 mt_sort_thread(void* arg)
1342 {
1343 	struct sort_list *list = arg;
1344 
1345 	g_sort_func(list->list, list->count, sizeof(struct sort_list_item *),
1346 	    (int(*)(const void *, const void *)) list_coll);
1347 
1348 	sem_post(&mtsem);
1349 
1350 	return (arg);
1351 }
1352 
1353 /*
1354  * Compare sub-lists. Empty sub-lists always go to the end of the list.
1355  */
1356 static int
1357 sub_list_cmp(struct sort_list *l1, struct sort_list *l2)
1358 {
1359 
1360 	if (l1 == l2)
1361 		return (0);
1362 	else {
1363 		if (l1->count == 0) {
1364 			return ((l2->count == 0) ? 0 : +1);
1365 		} else if (l2->count == 0) {
1366 			return (-1);
1367 		} else {
1368 			int ret;
1369 
1370 			ret = list_coll(&(l1->list[0]), &(l2->list[0]));
1371 			if (!ret)
1372 				return ((l1->sub_list_pos < l2->sub_list_pos) ?
1373 				    -1 : +1);
1374 			return (ret);
1375 		}
1376 	}
1377 }
1378 
1379 /*
1380  * Swap two array elements
1381  */
1382 static void
1383 sub_list_swap(struct sort_list **sl, size_t i1, size_t i2)
1384 {
1385 	struct sort_list *tmp;
1386 
1387 	tmp = sl[i1];
1388 	sl[i1] = sl[i2];
1389 	sl[i2] = tmp;
1390 }
1391 
1392 /* heap algorithm ==>> */
1393 
1394 /*
1395  * See heap sort algorithm
1396  * "Raises" last element to its right place
1397  */
1398 static void
1399 sub_list_swim(struct sort_list **sl, size_t indx)
1400 {
1401 
1402 	if (indx > 0) {
1403 		size_t parent_index;
1404 
1405 		parent_index = (indx - 1) >> 1;
1406 
1407 		if (sub_list_cmp(sl[indx], sl[parent_index]) < 0) {
1408 			/* swap child and parent and continue */
1409 			sub_list_swap(sl, indx, parent_index);
1410 			sub_list_swim(sl, parent_index);
1411 		}
1412 	}
1413 }
1414 
1415 /*
1416  * Sink the top element to its correct position
1417  */
1418 static void
1419 sub_list_sink(struct sort_list **sl, size_t indx, size_t size)
1420 {
1421 	size_t left_child_index;
1422 	size_t right_child_index;
1423 
1424 	left_child_index = indx + indx + 1;
1425 	right_child_index = left_child_index + 1;
1426 
1427 	if (left_child_index < size) {
1428 		size_t min_child_index;
1429 
1430 		min_child_index = left_child_index;
1431 
1432 		if ((right_child_index < size) &&
1433 		    (sub_list_cmp(sl[left_child_index],
1434 		    sl[right_child_index]) > 0))
1435 			min_child_index = right_child_index;
1436 		if (sub_list_cmp(sl[indx], sl[min_child_index]) > 0) {
1437 			sub_list_swap(sl, indx, min_child_index);
1438 			sub_list_sink(sl, min_child_index, size);
1439 		}
1440 	}
1441 }
1442 
1443 /* <<== heap algorithm */
1444 
1445 /*
1446  * Adds element to the "right" end
1447  */
1448 static void
1449 sub_list_push(struct sort_list *s, struct sort_list **sl, size_t size)
1450 {
1451 
1452 	sl[size++] = s;
1453 	sub_list_swim(sl, size - 1);
1454 }
1455 
1456 struct last_printed_item
1457 {
1458 	struct sort_list_item *item;
1459 };
1460 
1461 /*
1462  * Prints the current line of the file
1463  */
1464 static void
1465 sub_list_header_print(struct sort_list *sl, FILE *f_out,
1466     struct last_printed_item *lp)
1467 {
1468 
1469 	if (sl && sl->count && f_out && sl->list[0]->str) {
1470 		if (sort_opts_vals.uflag) {
1471 			if ((lp->item == NULL) || (list_coll(&(lp->item),
1472 			    &(sl->list[0])))) {
1473 				bwsfwrite(sl->list[0]->str, f_out,
1474 				    sort_opts_vals.zflag);
1475 				lp->item = sl->list[0];
1476 			}
1477 		} else
1478 			bwsfwrite(sl->list[0]->str, f_out,
1479 			    sort_opts_vals.zflag);
1480 	}
1481 }
1482 
1483 /*
1484  * Read next line
1485  */
1486 static void
1487 sub_list_next(struct sort_list *sl)
1488 {
1489 
1490 	if (sl && sl->count) {
1491 		sl->list += 1;
1492 		sl->count -= 1;
1493 	}
1494 }
1495 
1496 /*
1497  * Merge sub-lists to a file
1498  */
1499 static void
1500 merge_sub_lists(struct sort_list **sl, size_t n, FILE* f_out)
1501 {
1502 	struct last_printed_item lp;
1503 	size_t i;
1504 
1505 	memset(&lp,0,sizeof(lp));
1506 
1507 	/* construct the initial list: */
1508 	for (i = 0; i < n; i++)
1509 		sub_list_push(sl[i], sl, i);
1510 
1511 	while (sl[0]->count) { /* unfinished lists are always in front */
1512 		/* output the smallest line: */
1513 		sub_list_header_print(sl[0], f_out, &lp);
1514 		/* move to a new line, if possible: */
1515 		sub_list_next(sl[0]);
1516 		/* re-arrange the list: */
1517 		sub_list_sink(sl, 0, n);
1518 	}
1519 }
1520 
1521 /*
1522  * Merge sub-lists to a file
1523  */
1524 static void
1525 merge_list_parts(struct sort_list **parts, size_t n, const char *fn)
1526 {
1527 	FILE* f_out;
1528 
1529 	f_out = openfile(fn,"w");
1530 
1531 	merge_sub_lists(parts, n, f_out);
1532 
1533 	closefile(f_out, fn);
1534 }
1535 
1536 #endif /* defined(SORT_THREADS) */
1537 /*
1538  * Multi-threaded sort algorithm "driver"
1539  */
1540 static void
1541 mt_sort(struct sort_list *list,
1542     int(*sort_func)(void *, size_t, size_t, int(*)(const void *, const void *)),
1543     const char* fn)
1544 {
1545 #if defined(SORT_THREADS)
1546 	if (nthreads < 2 || list->count < MT_SORT_THRESHOLD) {
1547 		size_t nthreads_save = nthreads;
1548 		nthreads = 1;
1549 #endif
1550 		/* if single thread or small data, do simple sort */
1551 		sort_func(list->list, list->count,
1552 		    sizeof(struct sort_list_item *),
1553 		    (int(*)(const void *, const void *)) list_coll);
1554 		sort_list_dump(list, fn);
1555 #if defined(SORT_THREADS)
1556 		nthreads = nthreads_save;
1557 	} else {
1558 		/* multi-threaded sort */
1559 		struct sort_list **parts;
1560 		size_t avgsize, cstart, i;
1561 
1562 		/* array of sub-lists */
1563 		parts = sort_malloc(sizeof(struct sort_list*) * nthreads);
1564 		cstart = 0;
1565 		avgsize = list->count / nthreads;
1566 
1567 		/* set global system sort function */
1568 		g_sort_func = sort_func;
1569 
1570 		/* set sublists */
1571 		for (i = 0; i < nthreads; ++i) {
1572 			size_t sz = 0;
1573 
1574 			parts[i] = sort_malloc(sizeof(struct sort_list));
1575 			parts[i]->list = list->list + cstart;
1576 			parts[i]->memsize = 0;
1577 			parts[i]->sub_list_pos = i;
1578 
1579 			sz = (i == nthreads - 1) ? list->count - cstart :
1580 			    avgsize;
1581 
1582 			parts[i]->count = sz;
1583 
1584 			parts[i]->size = parts[i]->count;
1585 
1586 			cstart += sz;
1587 		}
1588 
1589 		/* init threads counting semaphore */
1590 		sem_init(&mtsem, 0, 0);
1591 
1592 		/* start threads */
1593 		for (i = 0; i < nthreads; ++i) {
1594 			pthread_t pth;
1595 			pthread_attr_t attr;
1596 
1597 			pthread_attr_init(&attr);
1598 			pthread_attr_setdetachstate(&attr, PTHREAD_DETACHED);
1599 
1600 			for (;;) {
1601 				int res = pthread_create(&pth, &attr,
1602 				    mt_sort_thread, parts[i]);
1603 
1604 				if (res >= 0)
1605 					break;
1606 				if (errno == EAGAIN) {
1607 					pthread_yield();
1608 					continue;
1609 				}
1610 				err(2, NULL);
1611 			}
1612 
1613 			pthread_attr_destroy(&attr);
1614 		}
1615 
1616 		/* wait for threads completion */
1617 		for (i = 0; i < nthreads; ++i) {
1618 			sem_wait(&mtsem);
1619 		}
1620 		/* destroy the semaphore - we do not need it anymore */
1621 		sem_destroy(&mtsem);
1622 
1623 		/* merge sorted sub-lists to the file */
1624 		merge_list_parts(parts, nthreads, fn);
1625 
1626 		/* free sub-lists data */
1627 		for (i = 0; i < nthreads; ++i) {
1628 			sort_free(parts[i]);
1629 		}
1630 		sort_free(parts);
1631 	}
1632 #endif /* defined(SORT_THREADS) */
1633 }
1634