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fsort.c revision 1.24 
      1 /*	$NetBSD: fsort.c,v 1.24 2002/12/24 15:15:01 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 /*
     40  * Read in the next bin.  If it fits in one segment sort it;
     41  * otherwise refine it by segment deeper by one character,
     42  * and try again on smaller bins.  Sort the final bin at this level
     43  * of recursion to keep the head of fstack at 0.
     44  * After PANIC passes, abort to merge sort.
     45  */
     46 #include "sort.h"
     47 #include "fsort.h"
     48 
     49 #ifndef lint
     50 __RCSID("$NetBSD: fsort.c,v 1.24 2002/12/24 15:15:01 jdolecek Exp $");
     51 __SCCSID("@(#)fsort.c	8.1 (Berkeley) 6/6/93");
     52 #endif /* not lint */
     53 
     54 #include <stdlib.h>
     55 #include <string.h>
     56 
     57 static const u_char **keylist = 0;
     58 u_char *buffer = 0, *linebuf = 0;
     59 size_t bufsize = DEFBUFSIZE;
     60 size_t linebuf_size;
     61 #define FSORTMAX 4
     62 int PANIC = FSORTMAX;
     63 
     64 struct tempfile fstack[MAXFCT];
     65 #define MSTART		(MAXFCT - MERGE_FNUM)
     66 #define	CHECKFSTACK(n)					\
     67 	if (n >= MAXFCT)				\
     68 		errx(2, "fstack: too many temporary files; use -H or sort in pieces")
     69 
     70 #define SALIGN(n) ((n+sizeof(length_t)-1) & ~(sizeof(length_t)-1))
     71 
     72 void
     73 fsort(binno, depth, top, filelist, nfiles, outfp, ftbl)
     74 	int binno, depth, top;
     75 	struct filelist *filelist;
     76 	int nfiles;
     77 	FILE *outfp;
     78 	struct field *ftbl;
     79 {
     80 	const u_char **keypos;
     81 	u_char *bufend, *tmpbuf;
     82 	u_char *weights;
     83 	int ntfiles, mfct = 0, total, i, maxb, lastb, panic = 0;
     84 	int c, nelem, base;
     85 	long sizes [NBINS+1];
     86 	get_func_t get;
     87 	struct recheader *crec;
     88 	struct field tfield[2];
     89 	FILE *prevfp, *tailfp[FSORTMAX+1];
     90 
     91 	memset(tailfp, 0, sizeof(tailfp));
     92 	prevfp = outfp;
     93 	memset(tfield, 0, sizeof(tfield));
     94 	if (ftbl[0].flags & R)
     95 		tfield[0].weights = Rascii;
     96 	else
     97 		tfield[0].weights = ascii;
     98 	tfield[0].icol.num = 1;
     99 	weights = ftbl[0].weights;
    100 	if (!buffer) {
    101 		buffer = malloc(bufsize);
    102 		keylist = malloc(MAXNUM * sizeof(u_char *));
    103 		memset(keylist, 0, MAXNUM * sizeof(u_char *));
    104 		if (!SINGL_FLD) {
    105 			linebuf_size = DEFLLEN;
    106 			if ((linebuf = malloc(linebuf_size)) == NULL)
    107 				errx(2, "cannot allocate memory");
    108 		}
    109 	}
    110 	bufend = buffer + bufsize;
    111 	if (binno >= 0) {
    112 		base = top + nfiles;
    113 		get = getnext;
    114 	} else {
    115 		base = 0;
    116 		if (SINGL_FLD)
    117 			get = makeline;
    118 		else
    119 			get = makekey;
    120 	}
    121 	for (;;) {
    122 		memset(sizes, 0, sizeof(sizes));
    123 		c = ntfiles = 0;
    124 		if (binno == weights[REC_D] &&
    125 		    !(SINGL_FLD && ftbl[0].flags & F)) {	/* pop */
    126 			rd_append(weights[REC_D], top,
    127 			    nfiles, prevfp, buffer, bufend);
    128 			break;
    129 		} else if (binno == weights[REC_D]) {
    130 			depth = 0;		/* start over on flat weights */
    131 			ftbl = tfield;
    132 			weights = ftbl[0].weights;
    133 		}
    134 		while (c != EOF) {
    135 			keypos = keylist;
    136 			nelem = 0;
    137 			crec = (RECHEADER *) buffer;
    138 
    139 		   do_read:
    140 			while((c = get(binno, top, filelist, nfiles, crec,
    141 			    bufend, ftbl)) == 0) {
    142 				*keypos++ = crec->data + depth;
    143 				if (++nelem == MAXNUM) {
    144 					c = BUFFEND;
    145 					break;
    146 				}
    147 				crec =(RECHEADER *)	((char *) crec +
    148 				SALIGN(crec->length) + sizeof(TRECHEADER));
    149 			}
    150 
    151 			if (c == BUFFEND && nelem < MAXNUM
    152 			    && bufsize < MAXBUFSIZE) {
    153 				const u_char **keyp;
    154 				u_char *oldb = buffer;
    155 
    156 				/* buffer was too small for data, allocate
    157 				 * bigger buffer */
    158 				bufsize *= 2;
    159 				buffer = realloc(buffer, bufsize);
    160 				if (!buffer) {
    161 					err(2, "failed to realloc buffer to %ld bytes",
    162 						(unsigned long) bufsize);
    163 				}
    164 				bufend = buffer + bufsize;
    165 
    166 				/* patch up keylist[] */
    167 				for(keyp = &keypos[-1]; keyp >= keylist; keyp--)
    168 					*keyp = buffer + (*keyp - oldb);
    169 
    170 				crec = (RECHEADER *) (buffer + ((u_char *)crec - oldb));
    171 				goto do_read;
    172 			}
    173 
    174 			if (c != BUFFEND && !ntfiles && !mfct) {
    175 				/* do not push */
    176 				continue;
    177 			}
    178 
    179 			/* push */
    180 			if (panic >= PANIC) {
    181 				fstack[MSTART + mfct].fp = ftmp();
    182 				if ((stable_sort)
    183 					? sradixsort(keylist, nelem,
    184 						weights, REC_D)
    185 					: radixsort(keylist, nelem,
    186 						weights, REC_D) )
    187 					err(2, NULL);
    188 				append(keylist, nelem, depth,
    189 				    fstack[MSTART + mfct].fp, putrec,
    190 				    ftbl);
    191 				mfct++;
    192 				/* reduce number of open files */
    193 				if (mfct == MERGE_FNUM ||(c == EOF && ntfiles)) {
    194 					/*
    195 					 * Only copy extra incomplete crec
    196 					 * data if there are any.
    197 					 */
    198 					int nodata = (bufend >= (u_char *)crec
    199 					    && bufend <= crec->data);
    200 
    201 					if (!nodata) {
    202 						tmpbuf = malloc(bufend -
    203 						    crec->data);
    204 						memmove(tmpbuf, crec->data,
    205 						    bufend - crec->data);
    206 					}
    207 
    208 					CHECKFSTACK(base + ntfiles);
    209 					fstack[base + ntfiles].fp = ftmp();
    210 					fmerge(0, MSTART, filelist,
    211 					    mfct, geteasy,
    212 					    fstack[base + ntfiles].fp,
    213 					    putrec, ftbl);
    214 					ntfiles++;
    215 					mfct = 0;
    216 
    217 					if (!nodata) {
    218 						memmove(crec->data, tmpbuf,
    219 						    bufend - crec->data);
    220 						free(tmpbuf);
    221 					}
    222 				}
    223 			} else {
    224 				CHECKFSTACK(base + ntfiles);
    225 				fstack[base + ntfiles].fp = ftmp();
    226 				onepass(keylist, depth, nelem, sizes,
    227 				    weights, fstack[base + ntfiles].fp);
    228 				ntfiles++;
    229 			}
    230 		}
    231 		if (!ntfiles && !mfct) {	/* everything in memory--pop */
    232 			if (nelem > 1
    233 			    && ((stable_sort)
    234 				? sradixsort(keylist, nelem, weights, REC_D)
    235 				: radixsort(keylist, nelem, weights, REC_D) ))
    236 				err(2, NULL);
    237 			if (nelem > 0)
    238 			  append(keylist, nelem, depth, outfp, putline, ftbl);
    239 			break;					/* pop */
    240 		}
    241 		if (panic >= PANIC) {
    242 			if (!ntfiles)
    243 				fmerge(0, MSTART, filelist, mfct, geteasy,
    244 				    outfp, putline, ftbl);
    245 			else
    246 				fmerge(0, base, filelist, ntfiles, geteasy,
    247 				    outfp, putline, ftbl);
    248 			break;
    249 
    250 		}
    251 		total = maxb = lastb = 0;	/* find if one bin dominates */
    252 		for (i = 0; i < NBINS; i++)
    253 			if (sizes[i]) {
    254 				if (sizes[i] > sizes[maxb])
    255 					maxb = i;
    256 				lastb = i;
    257 				total += sizes[i];
    258 			}
    259 		if (sizes[maxb] < max((total / 2) , BUFSIZE))
    260 			maxb = lastb;	/* otherwise pop after last bin */
    261 		fstack[base].lastb = lastb;
    262 		fstack[base].maxb = maxb;
    263 
    264 		/* start refining next level. */
    265 		getnext(-1, base, NULL, ntfiles, crec, bufend, 0); /* rewind */
    266 		for (i = 0; i < maxb; i++) {
    267 			if (!sizes[i])	/* bin empty; step ahead file offset */
    268 				getnext(i, base, NULL,ntfiles, crec, bufend, 0);
    269 			else
    270 				fsort(i, depth+1, base, filelist, ntfiles,
    271 					outfp, ftbl);
    272 		}
    273 
    274 		get = getnext;
    275 
    276 		if (lastb != maxb) {
    277 			if (prevfp != outfp)
    278 				tailfp[panic] = prevfp;
    279 			prevfp = ftmp();
    280 			for (i = maxb+1; i <= lastb; i++)
    281 				if (!sizes[i])
    282 					getnext(i, base, NULL, ntfiles, crec,
    283 					    bufend,0);
    284 				else
    285 					fsort(i, depth+1, base, filelist,
    286 					    ntfiles, prevfp, ftbl);
    287 		}
    288 
    289 		/* sort biggest (or last) bin at this level */
    290 		depth++;
    291 		panic++;
    292 		binno = maxb;
    293 		top = base;
    294 		nfiles = ntfiles;		/* so overwrite them */
    295 	}
    296 	if (prevfp != outfp) {
    297 		concat(outfp, prevfp);
    298 		fclose(prevfp);
    299 	}
    300 	for (i = panic; i >= 0; --i)
    301 		if (tailfp[i]) {
    302 			concat(outfp, tailfp[i]);
    303 			fclose(tailfp[i]);
    304 		}
    305 
    306 	/* If on top level, free our structures */
    307 	if (depth == 0) {
    308 		free(keylist), keylist = NULL;
    309 		free(buffer), buffer = NULL;
    310 	}
    311 }
    312 
    313 /*
    314  * This is one pass of radix exchange, dumping the bins to disk.
    315  */
    316 #define swap(a, b, t) t = a, a = b, b = t
    317 void
    318 onepass(a, depth, n, sizes, tr, fp)
    319 	const u_char **a;
    320 	int depth;
    321 	long n, sizes[];
    322 	u_char *tr;
    323 	FILE *fp;
    324 {
    325 	size_t tsizes[NBINS+1];
    326 	const u_char **bin[257], ***bp, ***bpmax, **top[256], ***tp;
    327 	static int histo[256];
    328 	int *hp;
    329 	int c;
    330 	const u_char **an, *t, **aj;
    331 	const u_char **ak, *r;
    332 
    333 	memset(tsizes, 0, sizeof(tsizes));
    334 	depth += sizeof(TRECHEADER);
    335 	an = &a[n];
    336 	for (ak = a; ak < an; ak++) {
    337 		histo[c = tr[**ak]]++;
    338 		tsizes[c] += ((const RECHEADER *) (*ak -= depth))->length;
    339 	}
    340 
    341 	bin[0] = a;
    342 	bpmax = bin + 256;
    343 	tp = top, hp = histo;
    344 	for (bp = bin; bp < bpmax; bp++) {
    345 		*tp++ = *(bp+1) = *bp + (c = *hp);
    346 		*hp++ = 0;
    347 		if (c <= 1)
    348 			continue;
    349 	}
    350 	for (aj = a; aj < an; *aj = r, aj = bin[c+1])
    351 		for (r = *aj; aj < (ak = --top[c = tr[r[depth]]]) ;)
    352 			swap(*ak, r, t);
    353 
    354 	for (ak = a, c = 0; c < 256; c++) {
    355 		an = bin[c+1];
    356 		n = an - ak;
    357 		tsizes[c] += n * sizeof(TRECHEADER);
    358 		/* tell getnext how many elements in this bin, this segment. */
    359 		EWRITE(&tsizes[c], sizeof(size_t), 1, fp);
    360 		sizes[c] += tsizes[c];
    361 		for (; ak < an; ++ak)
    362 			putrec((const RECHEADER *) *ak, fp);
    363 	}
    364 }
    365