File: [local] / src / usr.bin / make / buf.c (download)
Revision 1.9, Thu Dec 16 16:27:12 1999 UTC (24 years, 6 months ago) by espie
Branch: MAIN
Changes since 1.8: +30 -57 lines
Start cleaning up buf.c in earnest.
- Buf_Discard is only used to remove all the bytes in a buffer,
replace with Buf_Reset,
- buffer values are not read unless accessed first through Buf_GetAll,
no need to null-terminate it at every point.
- Buf_Expand need not check if the expansion is needed. That's Buf_AddChar
and Buf_AddChars responsability (otherwise, Buf_AddChar checks twice)
- Buf_Overflow only handles overflow. Adding the character is done in
every case anyway.
|
/* $OpenBSD: buf.c,v 1.9 1999/12/16 16:27:12 espie Exp $ */
/* $NetBSD: buf.c,v 1.9 1996/12/31 17:53:21 christos Exp $ */
/*
* Copyright (c) 1999 Marc Espie.
*
* Extensive code modifications for the OpenBSD project.
*
* 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 OPENBSD PROJECT 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 OPENBSD
* PROJECT 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) 1988, 1989, 1990 The Regents of the University of California.
* Copyright (c) 1988, 1989 by Adam de Boor
* Copyright (c) 1989 by Berkeley Softworks
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Adam de Boor.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)buf.c 8.1 (Berkeley) 6/6/93";
#else
static char rcsid[] = "$OpenBSD: buf.c,v 1.9 1999/12/16 16:27:12 espie Exp $";
#endif
#endif /* not lint */
/*-
* buf.c --
* Functions for automatically-expanded buffers.
*/
#include "sprite.h"
#include "make.h"
#include "buf.h"
#ifndef max
#define max(a,b) ((a) > (b) ? (a) : (b))
#endif
/*
* BufExpand --
* Expand the given buffer to hold the given number of additional
* chars.
* Makes sure there's room for an extra NULL char at the end of the
* buffer in case it holds a string.
*/
#define BufExpand(bp,nb) \
do { \
char *newBuf; \
size_t newSize = (bp)->size; \
\
do { \
newSize *= 2 ; \
(bp)->left = newSize - ((bp)->inPtr - (bp)->buffer); \
} while ((bp)->left < (nb)+1+BUF_MARGIN); \
newBuf = erealloc((bp)->buffer, newSize); \
(bp)->inPtr = newBuf + ((bp)->inPtr - (bp)->buffer); \
(bp)->outPtr = newBuf + ((bp)->outPtr - (bp)->buffer); \
(bp)->buffer = newBuf; \
(bp)->size = newSize; \
} while (0)
#define BUF_DEF_SIZE 256 /* Default buffer size */
#define BUF_MARGIN 256 /* Make sure we are comfortable */
/* Buf_AddChar hard case: buffer must be expanded to accommodate
* one more char. */
void
BufOverflow(bp)
Buffer bp;
{
BufExpand(bp, 1);
}
/*-
*-----------------------------------------------------------------------
* Buf_AddChars --
* Add a number of chars to the buffer.
*
* Side Effects:
* Guess what?
*
*-----------------------------------------------------------------------
*/
void
Buf_AddChars(bp, numBytes, bytesPtr)
Buffer bp;
size_t numBytes;
const char *bytesPtr;
{
if (bp->left < numBytes+1)
BufExpand(bp, numBytes);
memcpy(bp->inPtr, bytesPtr, numBytes);
bp->inPtr += numBytes;
bp->left -= numBytes;
}
/*-
*-----------------------------------------------------------------------
* Buf_GetAll --
* Get all the available data at once.
*
* Results:
* A pointer to the data and the number of chars available.
*
*-----------------------------------------------------------------------
*/
char *
Buf_GetAll(bp, numBytesPtr)
Buffer bp;
size_t *numBytesPtr;
{
if (numBytesPtr != NULL) {
*numBytesPtr = bp->inPtr - bp->outPtr;
}
*bp->inPtr = 0;
return (bp->outPtr);
}
/*-
*-----------------------------------------------------------------------
* Buf_Reset -
* Throw away all chars in a buffer.
*
* Side Effects:
* The chars are discarded.
*
*-----------------------------------------------------------------------
*/
void
Buf_Reset(bp)
Buffer bp;
{
bp->inPtr = bp->outPtr = bp->buffer;
bp->left = bp->size;
}
/*-
*-----------------------------------------------------------------------
* Buf_Size --
* Returns the number of chars in the given buffer. Doesn't include
* the null-terminating char.
*
* Results:
* The number of chars.
*
*-----------------------------------------------------------------------
*/
int
Buf_Size(buf)
Buffer buf;
{
return (buf->inPtr - buf->outPtr);
}
/*-
*-----------------------------------------------------------------------
* Buf_Init --
* Initialize a buffer. If no initial size is given, a reasonable
* default is used.
*
* Results:
* A buffer to be given to other functions in this library.
*
* Side Effects:
* The buffer is created, the space allocated and pointers
* initialized.
*
*-----------------------------------------------------------------------
*/
Buffer
Buf_Init(size)
size_t size; /* Initial size for the buffer */
{
Buffer bp; /* New Buffer */
bp = (Buffer)emalloc(sizeof(*bp));
if (size == 0) {
size = BUF_DEF_SIZE;
}
bp->left = bp->size = size;
bp->buffer = emalloc(size);
bp->inPtr = bp->outPtr = bp->buffer;
return (bp);
}
/*-
*-----------------------------------------------------------------------
* Buf_Destroy --
* Nuke a buffer and all its resources.
*
* Side Effects:
* The buffer is freed.
*
*-----------------------------------------------------------------------
*/
void
Buf_Destroy(buf, freeData)
Buffer buf; /* Buffer to destroy */
Boolean freeData; /* TRUE if the data should be destroyed as well */
{
if (freeData) {
free(buf->buffer);
}
free ((char *)buf);
}
/*-
*-----------------------------------------------------------------------
* Buf_ReplaceLastChar --
* Replace the last char in a buffer.
*
* Side Effects:
* If the buffer was empty intially, then a new byte will be added.
* Otherwise, the last byte is overwritten.
*
*-----------------------------------------------------------------------
*/
void
Buf_ReplaceLastChar(buf, byte)
Buffer buf; /* buffer to augment */
char byte; /* byte to be written */
{
if (buf->inPtr == buf->outPtr)
Buf_AddChar(buf, byte);
else
*(buf->inPtr - 1) = byte;
}