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buf.c revision 1.37
      1 /*	$NetBSD: buf.c,v 1.37 2020/08/23 08:21:50 rillig Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Adam de Boor.
      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. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 /*
     36  * Copyright (c) 1988, 1989 by Adam de Boor
     37  * Copyright (c) 1989 by Berkeley Softworks
     38  * All rights reserved.
     39  *
     40  * This code is derived from software contributed to Berkeley by
     41  * Adam de Boor.
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. All advertising materials mentioning features or use of this software
     52  *    must display the following acknowledgement:
     53  *	This product includes software developed by the University of
     54  *	California, Berkeley and its contributors.
     55  * 4. Neither the name of the University nor the names of its contributors
     56  *    may be used to endorse or promote products derived from this software
     57  *    without specific prior written permission.
     58  *
     59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     69  * SUCH DAMAGE.
     70  */
     71 
     72 #ifndef MAKE_NATIVE
     73 static char rcsid[] = "$NetBSD: buf.c,v 1.37 2020/08/23 08:21:50 rillig Exp $";
     74 #else
     75 #include <sys/cdefs.h>
     76 #ifndef lint
     77 #if 0
     78 static char sccsid[] = "@(#)buf.c	8.1 (Berkeley) 6/6/93";
     79 #else
     80 __RCSID("$NetBSD: buf.c,v 1.37 2020/08/23 08:21:50 rillig Exp $");
     81 #endif
     82 #endif /* not lint */
     83 #endif
     84 
     85 /* Functions for automatically-expanded null-terminated buffers. */
     86 
     87 #include <limits.h>
     88 #include "make.h"
     89 
     90 /* Extend the buffer for adding a single byte. */
     91 void
     92 Buf_Expand_1(Buffer *bp)
     93 {
     94     bp->size += MAX(bp->size, 16);
     95     bp->buffer = bmake_realloc(bp->buffer, bp->size);
     96 }
     97 
     98 /* Add the given bytes to the buffer. */
     99 void
    100 Buf_AddBytes(Buffer *bp, const char *bytesPtr, size_t numBytes)
    101 {
    102     size_t count = bp->count;
    103     char *ptr;
    104 
    105     if (__predict_false(count + numBytes >= bp->size)) {
    106 	bp->size += MAX(bp->size, numBytes + 16);
    107 	bp->buffer = bmake_realloc(bp->buffer, bp->size);
    108     }
    109 
    110     ptr = bp->buffer + count;
    111     bp->count = count + numBytes;
    112     memcpy(ptr, bytesPtr, numBytes);
    113     ptr[numBytes] = '\0';
    114 }
    115 
    116 /* Add the bytes between start and end to the buffer. */
    117 void
    118 Buf_AddBytesBetween(Buffer *bp, const char *start, const char *end)
    119 {
    120     Buf_AddBytes(bp, start, (size_t)(end - start));
    121 }
    122 
    123 /* Add the given string to the buffer. */
    124 void
    125 Buf_AddStr(Buffer *bp, const char *str)
    126 {
    127     Buf_AddBytes(bp, str, strlen(str));
    128 }
    129 
    130 /* Add the given number to the buffer. */
    131 void
    132 Buf_AddInt(Buffer *bp, int n)
    133 {
    134     enum {
    135 	bits = sizeof(int) * CHAR_BIT,
    136 	max_octal_digits = (bits + 2) / 3,
    137 	max_decimal_digits = /* at most */ max_octal_digits,
    138 	max_sign_chars = 1,
    139 	buf_size = max_sign_chars + max_decimal_digits + 1
    140     };
    141     char buf[buf_size];
    142 
    143     size_t len = (size_t)snprintf(buf, sizeof buf, "%d", n);
    144     Buf_AddBytes(bp, buf, len);
    145 }
    146 
    147 /* Get the data (usually a string) from the buffer.
    148  * The returned data is valid until the next modifying operation
    149  * on the buffer.
    150  *
    151  * Returns the pointer to the data and optionally the length of the
    152  * data in the buffer. */
    153 char *
    154 Buf_GetAll(Buffer *bp, size_t *numBytesPtr)
    155 {
    156     if (numBytesPtr != NULL)
    157 	*numBytesPtr = bp->count;
    158     return bp->buffer;
    159 }
    160 
    161 /* Mark the buffer as empty, so it can be filled with data again. */
    162 void
    163 Buf_Empty(Buffer *bp)
    164 {
    165     bp->count = 0;
    166     bp->buffer[0] = '\0';
    167 }
    168 
    169 /* Initialize a buffer.
    170  * If the given initial size is 0, a reasonable default is used. */
    171 void
    172 Buf_Init(Buffer *bp, size_t size)
    173 {
    174     if (size <= 0) {
    175 	size = 256;
    176     }
    177     bp->size = size;
    178     bp->count = 0;
    179     bp->buffer = bmake_malloc(size);
    180     bp->buffer[0] = '\0';
    181 }
    182 
    183 /* Reset the buffer.
    184  * If freeData is TRUE, the data from the buffer is freed as well.
    185  * Otherwise it is kept and returned. */
    186 char *
    187 Buf_Destroy(Buffer *buf, Boolean freeData)
    188 {
    189     char *data = buf->buffer;
    190     if (freeData) {
    191 	free(data);
    192 	data = NULL;
    193     }
    194 
    195     buf->size = 0;
    196     buf->count = 0;
    197     buf->buffer = NULL;
    198 
    199     return data;
    200 }
    201 
    202 #ifndef BUF_COMPACT_LIMIT
    203 # define BUF_COMPACT_LIMIT 128		/* worthwhile saving */
    204 #endif
    205 
    206 /* Reset the buffer and return its data.
    207  *
    208  * If the buffer size is much greater than its content,
    209  * a new buffer will be allocated and the old one freed. */
    210 char *
    211 Buf_DestroyCompact(Buffer *buf)
    212 {
    213 #if BUF_COMPACT_LIMIT > 0
    214     if (buf->size - buf->count >= BUF_COMPACT_LIMIT) {
    215 	/* We trust realloc to be smart */
    216 	char *data = bmake_realloc(buf->buffer, buf->count + 1);
    217 	data[buf->count] = '\0';
    218 	Buf_Destroy(buf, FALSE);
    219 	return data;
    220     }
    221 #endif
    222     return Buf_Destroy(buf, FALSE);
    223 }
    224