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mirror of https://git.FreeBSD.org/src.git synced 2024-12-04 09:09:56 +00:00
freebsd/usr.bin/make/buf.c
Hartmut Brandt b8900c134b None of the users of Buf_Discard used it to get rid of only a part of
the buffer. So replace Buf_Discard by Buf_Clear which just gets rid
of the entire contents.

Submitted by:	Max Okumoto <okumoto@ucsd.edu>
2005-02-04 13:34:16 +00:00

274 lines
6.7 KiB
C

/*-
* Copyright (c) 1988, 1989, 1990, 1993
* The Regents of the University of California. All rights reserved.
* 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.
*
* @(#)buf.c 8.1 (Berkeley) 6/6/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*-
* buf.c --
* Functions for automatically-expanded buffers.
*/
#include <string.h>
#include <stdlib.h>
#include "buf.h"
#include "sprite.h"
#include "util.h"
#ifndef max
#define max(a,b) ((a) > (b) ? (a) : (b))
#endif
/*
* BufExpand --
* Expand the given buffer to hold the given number of additional
* bytes.
* Makes sure there's room for an extra NULL byte at the end of the
* buffer in case it holds a string.
*/
#define BufExpand(bp, nb) do { \
if ((bp)->left < (nb) + 1) { \
int newSize = (bp)->size + max((nb) + 1, BUF_ADD_INC); \
Byte *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; \
(bp)->left = newSize - ((bp)->inPtr - (bp)->buffer); \
} \
} while (0)
#define BUF_DEF_SIZE 256 /* Default buffer size */
#define BUF_ADD_INC 256 /* Expansion increment when Adding */
#define BUF_UNGET_INC 16 /* Expansion increment when Ungetting */
/*-
*-----------------------------------------------------------------------
* Buf_OvAddByte --
* Add a single byte to the buffer. left is zero or negative.
*
* Results:
* None.
*
* Side Effects:
* The buffer may be expanded.
*
*-----------------------------------------------------------------------
*/
void
Buf_OvAddByte(Buffer *bp, Byte byte)
{
bp->left = 0;
BufExpand(bp, 1);
*bp->inPtr++ = byte;
bp->left--;
/*
* Null-terminate
*/
*bp->inPtr = 0;
}
/*-
*-----------------------------------------------------------------------
* Buf_AddBytes --
* Add a number of bytes to the buffer.
*
* Results:
* None.
*
* Side Effects:
* Guess what?
*
*-----------------------------------------------------------------------
*/
void
Buf_AddBytes(Buffer *bp, size_t numBytes, const Byte *bytesPtr)
{
BufExpand(bp, numBytes);
memcpy(bp->inPtr, bytesPtr, numBytes);
bp->inPtr += numBytes;
bp->left -= numBytes;
/*
* Null-terminate
*/
*bp->inPtr = 0;
}
/*-
*-----------------------------------------------------------------------
* Buf_GetAll --
* Get all the available data at once.
*
* Results:
* A pointer to the data and the number of bytes available.
*
* Side Effects:
* None.
*
*-----------------------------------------------------------------------
*/
Byte *
Buf_GetAll(Buffer *bp, size_t *numBytesPtr)
{
if (numBytesPtr != NULL)
*numBytesPtr = bp->inPtr - bp->outPtr;
return (bp->outPtr);
}
/*-
*-----------------------------------------------------------------------
* Buf_Size --
* Returns the number of bytes in the given buffer. Doesn't include
* the null-terminating byte.
*
* Results:
* The number of bytes.
*
* Side Effects:
* None.
*
*-----------------------------------------------------------------------
*/
size_t
Buf_Size(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_t size)
{
Buffer *bp; /* New Buffer */
bp = 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;
*bp->inPtr = 0;
return (bp);
}
/*-
*-----------------------------------------------------------------------
* Buf_Destroy --
* Destroy a buffer, and optionally free its data, too.
*
* Results:
* None.
*
* Side Effects:
* The buffer is freed.
*
*-----------------------------------------------------------------------
*/
void
Buf_Destroy(Buffer *buf, Boolean freeData)
{
if (freeData)
free(buf->buffer);
free(buf);
}
/*-
*-----------------------------------------------------------------------
* Buf_ReplaceLastByte --
* Replace the last byte in a buffer.
*
* Results:
* None.
*
* Side Effects:
* If the buffer was empty intially, then a new byte will be added.
* Otherwise, the last byte is overwritten.
*
*-----------------------------------------------------------------------
*/
void
Buf_ReplaceLastByte(Buffer *buf, Byte byte)
{
if (buf->inPtr == buf->outPtr)
Buf_AddByte(buf, byte);
else
*(buf->inPtr - 1) = byte;
}
void
Buf_Clear(Buffer *bp)
{
bp->inPtr = bp->buffer;
bp->outPtr = bp->buffer;
bp->left = bp->size;
bp->inPtr[0] = '\0';
}