NetBSD/usr.bin/sort/fsort.c

203 lines
6.5 KiB
C

/* $NetBSD: fsort.c,v 1.47 2010/02/05 21:58:41 enami Exp $ */
/*-
* Copyright (c) 2000-2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Ben Harris and Jaromir Dolecek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Peter McIlroy.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Read in a block of records (until 'enough').
* sort, write to temp file.
* Merge sort temp files into output file
* Small files miss out the temp file stage.
* Large files might get multiple merges.
*/
#include "sort.h"
#include "fsort.h"
__RCSID("$NetBSD: fsort.c,v 1.47 2010/02/05 21:58:41 enami Exp $");
#include <stdlib.h>
#include <string.h>
#define SALIGN(n) ((n+sizeof(length_t)-1) & ~(sizeof(length_t)-1))
void
fsort(struct filelist *filelist, int nfiles, FILE *outfp, struct field *ftbl)
{
RECHEADER **keylist;
RECHEADER **keypos, **keyp;
RECHEADER *buffer;
size_t bufsize = DEFBUFSIZE;
u_char *bufend;
int mfct = 0;
int c, nelem;
get_func_t get;
RECHEADER *crec;
RECHEADER *nbuffer;
FILE *fp, *tmp_fp;
int file_no;
int max_recs = DEBUG('m') ? 16 : MAXNUM;
buffer = allocrec(NULL, bufsize);
bufend = (u_char *)buffer + bufsize;
/* Allocate double length keymap for radix_sort */
keylist = malloc(2 * max_recs * sizeof(*keylist));
if (buffer == NULL || keylist == NULL)
err(2, "failed to malloc initial buffer or keylist");
if (SINGL_FLD)
/* Key and data are one! */
get = makeline;
else
/* Key (merged key fields) added before data */
get = makekey;
file_no = 0;
fp = fopen(filelist->names[0], "r");
if (fp == NULL)
err(2, "%s", filelist->names[0]);
/* Loop through reads of chunk of input files that get sorted
* and then merged together. */
for (;;) {
keypos = keylist;
nelem = 0;
crec = buffer;
makeline_copydown(crec);
/* Loop reading records */
for (;;) {
c = get(fp, crec, bufend, ftbl);
/* 'c' is 0, EOF or BUFFEND */
if (c == 0) {
/* Save start of key in input buffer */
*keypos++ = crec;
if (++nelem == max_recs) {
c = BUFFEND;
break;
}
crec = (RECHEADER *)(crec->data + SALIGN(crec->length));
continue;
}
if (c == EOF) {
/* try next file */
if (++file_no >= nfiles)
/* no more files */
break;
fp = fopen(filelist->names[file_no], "r");
if (fp == NULL)
err(2, "%s", filelist->names[file_no]);
continue;
}
if (nelem >= max_recs
|| (bufsize >= MAXBUFSIZE && nelem > 8))
/* Need to sort and save this lot of data */
break;
/* c == BUFFEND, and we can process more data */
/* Allocate a larger buffer for this lot of data */
bufsize *= 2;
nbuffer = allocrec(buffer, bufsize);
if (!nbuffer) {
err(2, "failed to realloc buffer to %zu bytes",
bufsize);
}
/* patch up keylist[] */
for (keyp = &keypos[-1]; keyp >= keylist; keyp--)
*keyp = nbuffer + (*keyp - buffer);
crec = nbuffer + (crec - buffer);
buffer = nbuffer;
bufend = (u_char *)buffer + bufsize;
}
/* Sort this set of records */
radix_sort(keylist, keylist + max_recs, nelem);
if (c == EOF && mfct == 0) {
/* all the data is (sorted) in the buffer */
append(keylist, nelem, outfp,
DEBUG('k') ? putkeydump : putline);
break;
}
/* Save current data to a temporary file for a later merge */
if (nelem != 0) {
tmp_fp = ftmp();
append(keylist, nelem, tmp_fp, putrec);
save_for_merge(tmp_fp, geteasy, ftbl);
}
mfct = 1;
if (c == EOF) {
/* merge to output file */
merge_sort(outfp,
DEBUG('k') ? putkeydump : putline, ftbl);
break;
}
}
free(keylist);
keylist = NULL;
free(buffer);
buffer = NULL;
}