bin/make/buf.c

   1 /*      $NetBSD: buf.c,v 1.25 2012/04/24 20:26:58 sjg 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 1.25 2012/04/24 20:26:58 sjg 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 1.25 2012/04/24 20:26:58 sjg Exp $");
  81 #endif
  82 #endif /* not lint */
  83 #endif
  84
  85 /*-
  86  * buf.c --
  87  *      Functions for automatically-expanded buffers.
  88  */
  89
  90 #include    "make.h"
  91 #include    "buf.h"
  92
  93 #ifndef max
  94 #define max(a,b)  ((a) > (b) ? (a) : (b))
  95 #endif
  96
  97 #define BUF_DEF_SIZE    256     /* Default buffer size */
  98
  99 /*-
 100  *-----------------------------------------------------------------------
 101  * Buf_Expand_1 --
 102  *      Extend buffer for single byte add.
 103  *
 104  *-----------------------------------------------------------------------
 105  */
 106 void
 107 Buf_Expand_1(Buffer *bp)
 108 {
 109     bp->size += max(bp->size, 16);
 110     bp->buffer = bmake_realloc(bp->buffer, bp->size);
 111 }
 112
 113 /*-
 114  *-----------------------------------------------------------------------
 115  * Buf_AddBytes --
 116  *      Add a number of bytes to the buffer.
 117  *
 118  * Results:
 119  *      None.
 120  *
 121  * Side Effects:
 122  *      Guess what?
 123  *
 124  *-----------------------------------------------------------------------
 125  */
 126 void
 127 Buf_AddBytes(Buffer *bp, int numBytes, const Byte *bytesPtr)
 128 {
 129     int count = bp->count;
 130     Byte *ptr;
 131
 132     if (__predict_false(count + numBytes >= bp->size)) {
 133         bp->size += max(bp->size, numBytes + 16);
 134         bp->buffer = bmake_realloc(bp->buffer, bp->size);
 135     }
 136
 137     ptr = bp->buffer + count;
 138     bp->count = count + numBytes;
 139     ptr[numBytes] = 0;
 140     memcpy(ptr, bytesPtr, numBytes);
 141 }
 142
 143 /*-
 144  *-----------------------------------------------------------------------
 145  * Buf_GetAll --
 146  *      Get all the available data at once.
 147  *
 148  * Results:
 149  *      A pointer to the data and the number of bytes available.
 150  *
 151  * Side Effects:
 152  *      None.
 153  *
 154  *-----------------------------------------------------------------------
 155  */
 156 Byte *
 157 Buf_GetAll(Buffer *bp, int *numBytesPtr)
 158 {
 159
 160     if (numBytesPtr != NULL)
 161         *numBytesPtr = bp->count;
 162
 163     return (bp->buffer);
 164 }
 165
 166 /*-
 167  *-----------------------------------------------------------------------
 168  * Buf_Empty --
 169  *      Throw away bytes in a buffer.
 170  *
 171  * Results:
 172  *      None.
 173  *
 174  * Side Effects:
 175  *      The bytes are discarded.
 176  *
 177  *-----------------------------------------------------------------------
 178  */
 179 void
 180 Buf_Empty(Buffer *bp)
 181 {
 182
 183     bp->count = 0;
 184     *bp->buffer = 0;
 185 }
 186
 187 /*-
 188  *-----------------------------------------------------------------------
 189  * Buf_Init --
 190  *      Initialize a buffer. If no initial size is given, a reasonable
 191  *      default is used.
 192  *
 193  * Input:
 194  *      size            Initial size for the buffer
 195  *
 196  * Results:
 197  *      A buffer to be given to other functions in this library.
 198  *
 199  * Side Effects:
 200  *      The buffer is created, the space allocated and pointers
 201  *      initialized.
 202  *
 203  *-----------------------------------------------------------------------
 204  */
 205 void
 206 Buf_Init(Buffer *bp, int size)
 207 {
 208     if (size <= 0) {
 209         size = BUF_DEF_SIZE;
 210     }
 211     bp->size = size;
 212     bp->count = 0;
 213     bp->buffer = bmake_malloc(size);
 214     *bp->buffer = 0;
 215 }
 216
 217 /*-
 218  *-----------------------------------------------------------------------
 219  * Buf_Destroy --
 220  *      Nuke a buffer and all its resources.
 221  *
 222  * Input:
 223  *      buf             Buffer to destroy
 224  *      freeData        TRUE if the data should be destroyed
 225  *
 226  * Results:
 227  *      Data buffer, NULL if freed
 228  *
 229  * Side Effects:
 230  *      The buffer is freed.
 231  *
 232  *-----------------------------------------------------------------------
 233  */
 234 Byte *
 235 Buf_Destroy(Buffer *buf, Boolean freeData)
 236 {
 237     Byte *data;
 238
 239     data = buf->buffer;
 240     if (freeData) {
 241         free(data);
 242         data = NULL;
 243     }
 244
 245     buf->size = 0;
 246     buf->count = 0;
 247     buf->buffer = NULL;
 248
 249     return data;
 250 }
 251
 252
 253 /*-
 254  *-----------------------------------------------------------------------
 255  * Buf_DestroyCompact --
 256  *      Nuke a buffer and return its data.
 257  *
 258  * Input:
 259  *      buf             Buffer to destroy
 260  *
 261  * Results:
 262  *      Data buffer
 263  *
 264  * Side Effects:
 265  *      If the buffer size is much greater than its content,
 266  *      a new buffer will be allocated and the old one freed.
 267  *
 268  *-----------------------------------------------------------------------
 269  */
 270 #ifndef BUF_COMPACT_LIMIT
 271 # define BUF_COMPACT_LIMIT 128          /* worthwhile saving */
 272 #endif
 273
 274 Byte *
 275 Buf_DestroyCompact(Buffer *buf)
 276 {
 277 #if BUF_COMPACT_LIMIT > 0
 278     Byte *data;
 279
 280     if (buf->size - buf->count >= BUF_COMPACT_LIMIT) {
 281         /* We trust realloc to be smart */
 282         data = bmake_realloc(buf->buffer, buf->count + 1);
 283         if (data) {
 284             data[buf->count] = 0;
 285             Buf_Destroy(buf, FALSE);
 286             return data;
 287         }
 288     }
 289 #endif
 290     return Buf_Destroy(buf, FALSE);
 291 }