1 /*
   2  * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "Buffer.hpp"
  26 
  27 #include <string.h>
  28 
  29 Buffer::Buffer(int bufSize) {
  30   buf = new char[bufSize];
  31   sz = bufSize;
  32   fill = 0;
  33   drain = 0;
  34 }
  35 
  36 Buffer::~Buffer() {
  37   delete[] buf;
  38 }
  39 
  40 char*
  41 Buffer::fillPos() {
  42   return buf + fill;
  43 }
  44 
  45 int
  46 Buffer::remaining() {
  47   return sz - fill;
  48 }
  49 
  50 int
  51 Buffer::size() {
  52   return sz;
  53 }
  54 
  55 bool
  56 Buffer::incrFillPos(int amt) {
  57   if (fill + amt >= sz) {
  58     return false;
  59   }
  60   fill += amt;
  61   return true;
  62 }
  63 
  64 int
  65 Buffer::readByte() {
  66   if (drain < fill) {
  67     return buf[drain++] & 0xFF;
  68   } else {
  69     return -1;
  70   }
  71 }
  72 
  73 int
  74 Buffer::readBytes(char* data, int len) {
  75   int numRead = 0;
  76   while (numRead < len) {
  77     int c = readByte();
  78     if (c < 0) break;
  79     data[numRead++] = (char) c;
  80   }
  81   return numRead;
  82 }
  83 
  84 char*
  85 Buffer::drainPos() {
  86   return buf + drain;
  87 }
  88 
  89 int
  90 Buffer::drainRemaining() {
  91   return fill - drain;
  92 }
  93 
  94 bool
  95 Buffer::incrDrainPos(int amt) {
  96   if (drainRemaining() < amt) {
  97     return false;
  98   }
  99   drain += amt;
 100   return true;
 101 }
 102 
 103 void
 104 Buffer::compact() {
 105   // Copy down data
 106   memmove(buf, buf + drain, fill - drain);
 107   // Adjust positions
 108   fill -= drain;
 109   drain = 0;
 110 }