NetBSD/usr.bin/sort/files.c

/*	$NetBSD: files.c,v 1.35 2009/08/22 10:53:28 dsl 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.
 */

#include "sort.h"
#include "fsort.h"

#ifndef lint
__RCSID("$NetBSD: files.c,v 1.35 2009/08/22 10:53:28 dsl Exp $");
__SCCSID("@(#)files.c	8.1 (Berkeley) 6/6/93");
#endif /* not lint */

#include <string.h>

static ssize_t	seq(FILE *, u_char **);

/*
 * this is called when there is no special key. It's only called
 * in the first fsort pass.
 */
int
makeline(int flno, int top, struct filelist *filelist, int nfiles,
    RECHEADER *recbuf, u_char *bufend, struct field *dummy2)
{
	static u_char *obufend;
	static size_t osz;
	u_char *pos;
	static int filenum = 0, overflow = 0;
	static FILE *fp = 0;
	int c;

	c = 0;		/* XXXGCC -Wuninitialized [pmppc] */

	pos = recbuf->data;
	if (overflow) {
		/*
		 * Buffer shortage is solved by either of two ways:
		 * o flush previous buffered data and start using the
		 *   buffer from start (see fsort())
		 * o realloc buffer and bump bufend
		 * 
		 * The former is preferred, realloc is only done when
		 * there is exactly one item in buffer which does not fit. 
		 */
		if (bufend == obufend)
			memmove(pos, bufend - osz, osz);

		pos += osz;
		overflow = 0;
	}

	for (;;) {
		if (flno >= 0 && (fp = fstack[flno].fp) == NULL)
			return (EOF);
		else if (fp == NULL) {
			if (filenum  >= nfiles)
				return (EOF);
			if (!(fp = fopen(filelist->names[filenum], "r")))
				err(2, "%s", filelist->names[filenum]);
			filenum++;
		}
		while ((pos < bufend) && ((c = getc(fp)) != EOF)) {
			*pos++ = c;
			if (c == REC_D) {
				recbuf->offset = 0;
				recbuf->length = pos - recbuf->data;
				return (0);
			}
		}
		if (pos >= bufend) {
			if (recbuf->data < bufend) {
				overflow = 1;
				obufend = bufend;
				osz = (pos - recbuf->data);
			}
			return (BUFFEND);
		} else if (c == EOF) {
			if (recbuf->data != pos) {
				*pos++ = REC_D;
				recbuf->offset = 0;
				recbuf->length = pos - recbuf->data;
				return (0);
			}
			FCLOSE(fp);
			fp = 0;
			if (flno >= 0)
				fstack[flno].fp = 0;
		} else {
			
			warnx("makeline: line too long: ignoring '%.100s...'", recbuf->data);

			/* Consume the rest of line from input */
			while ((c = getc(fp)) != REC_D && c != EOF)
				;

			recbuf->offset = 0;
			recbuf->length = 0;

			return (BUFFEND);
		}
	}
}

/*
 * This generates keys. It's only called in the first fsort pass
 */
int
makekey(int flno, int top, struct filelist *filelist, int nfiles,
    RECHEADER *recbuf, u_char *bufend, struct field *ftbl)
{
	static int filenum = 0;
	static FILE *dbdesc = 0;
	static u_char *line_data;
	static ssize_t line_size;
	static int overflow = 0;

	/* We get re-entered after returning BUFFEND - save old data */
	if (overflow) {
		overflow = enterkey(recbuf, bufend, line_data, line_size, ftbl);
		return overflow ? BUFFEND : 0;
	}

	/* Loop through files until we find a line of input */
	for (;;) {
		if (flno >= 0) {
			if (!(dbdesc = fstack[flno].fp))
				return (EOF);
		} else if (!dbdesc) {
			if (filenum  >= nfiles)
				return (EOF);
			dbdesc = fopen(filelist->names[filenum], "r");
			if (!dbdesc)
				err(2, "%s", filelist->names[filenum]);
			filenum++;
		}
		line_size = seq(dbdesc, &line_data);
		if (line_size != 0)
			/* Got a line */
			break;

		/* End of file ... */
		FCLOSE(dbdesc);
		dbdesc = 0;
		if (flno >= 0)
			fstack[flno].fp = 0;
	}

	if (line_size > bufend - recbuf->data) {
		overflow = 1;
	} else {
		overflow = enterkey(recbuf, bufend, line_data, line_size, ftbl);
	}
	return overflow ? BUFFEND : 0;
}

/*
 * get a line of input from fp
 */
static ssize_t
seq(FILE *fp, u_char **line)
{
	static u_char *buf;
	static size_t buf_size = DEFLLEN;
	u_char *end, *pos;
	int c;
	u_char *new_buf;

	if (!buf) {
		/* one-time initialization */
		buf = malloc(buf_size);
		if (!buf)
		    err(2, "malloc of linebuf for %zu bytes failed",
			    buf_size);
	}

	end = buf + buf_size;
	pos = buf;
	while ((c = getc(fp)) != EOF) {
		*pos++ = c;
		if (c == REC_D) {
			*line = buf;
			return pos - buf;
		}
		if (pos == end) {
			/* Long line - double size of buffer */
			/* XXX: Check here for stupidly long lines */
			buf_size *= 2;
			new_buf = realloc(buf, buf_size);
			if (!new_buf)
				err(2, "realloc of linebuf to %zu bytes failed",
					buf_size);
		
			end = new_buf + buf_size;
			pos = new_buf + (pos - buf);
			buf = new_buf;
		}
	}

	if (pos != buf) {
		/* EOF part way through line - add line terminator */
		*pos++ = REC_D;
		*line = buf;
		return pos - buf;
	}

	return 0;
}

/*
 * write a key/line pair to a temporary file
 */
void
putrec(const RECHEADER *rec, FILE *fp)
{
	EWRITE(rec, 1, rec->length + REC_DATA_OFFSET, fp);
}

/*
 * write a line to output
 */
void
putline(const RECHEADER *rec, FILE *fp)
{
	EWRITE(rec->data+rec->offset, 1, rec->length - rec->offset, fp);
}

/*
 * write dump of key to output (for -Dk)
 */
void
putkeydump(const RECHEADER *rec, FILE *fp)
{
	EWRITE(rec, 1, rec->offset + REC_DATA_OFFSET, fp);
}

/*
 * get a record from a temporary file. (Used by merge sort.)
 */
int
geteasy(int flno, int top, struct filelist *filelist, int nfiles,
    RECHEADER *rec, u_char *end, struct field *dummy2)
{
	int i;
	FILE *fp;

	fp = fstack[flno].fp;
	if ((u_char *) rec > end - REC_DATA_OFFSET)
		return (BUFFEND);
	if (!fread(rec, 1, REC_DATA_OFFSET, fp)) {
		fclose(fp);
		fstack[flno].fp = 0;
		return (EOF);
	}
	if (end - rec->data < (ptrdiff_t)rec->length) {
		for (i = REC_DATA_OFFSET - 1; i >= 0;  i--)
			ungetc(*((char *) rec + i), fp);
		return (BUFFEND);
	}
	fread(rec->data, rec->length, 1, fp);
	return (0);
}