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1 /* |
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2 * Copyright 1999-2005 Sun Microsystems, Inc. All Rights Reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Sun designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Sun in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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22 * CA 95054 USA or visit www.sun.com if you need additional information or |
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23 * have any questions. |
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24 */ |
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25 |
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26 package com.sun.tools.javac.util; |
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27 |
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28 import java.io.*; |
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29 |
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30 /** A byte buffer is a flexible array which grows when elements are |
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31 * appended. There are also methods to append names to byte buffers |
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32 * and to convert byte buffers to names. |
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33 * |
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34 * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
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35 * you write code that depends on this, you do so at your own risk. |
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36 * This code and its internal interfaces are subject to change or |
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37 * deletion without notice.</b> |
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38 */ |
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39 public class ByteBuffer { |
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40 |
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41 /** An array holding the bytes in this buffer; can be grown. |
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42 */ |
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43 public byte[] elems; |
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44 |
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45 /** The current number of defined bytes in this buffer. |
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46 */ |
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47 public int length; |
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48 |
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49 /** Create a new byte buffer. |
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50 */ |
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51 public ByteBuffer() { |
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52 this(64); |
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53 } |
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54 |
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55 /** Create a new byte buffer with an initial elements array |
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56 * of given size. |
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57 */ |
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58 public ByteBuffer(int initialSize) { |
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59 elems = new byte[initialSize]; |
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60 length = 0; |
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61 } |
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62 |
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63 private void copy(int size) { |
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64 byte[] newelems = new byte[size]; |
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65 System.arraycopy(elems, 0, newelems, 0, elems.length); |
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66 elems = newelems; |
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67 } |
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68 |
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69 /** Append byte to this buffer. |
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70 */ |
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71 public void appendByte(int b) { |
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72 if (length >= elems.length) copy(elems.length * 2); |
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73 elems[length++] = (byte)b; |
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74 } |
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75 |
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76 /** Append `len' bytes from byte array, |
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77 * starting at given `start' offset. |
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78 */ |
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79 public void appendBytes(byte[] bs, int start, int len) { |
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80 while (length + len > elems.length) copy(elems.length * 2); |
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81 System.arraycopy(bs, start, elems, length, len); |
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82 length += len; |
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83 } |
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84 |
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85 /** Append all bytes from given byte array. |
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86 */ |
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87 public void appendBytes(byte[] bs) { |
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88 appendBytes(bs, 0, bs.length); |
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89 } |
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90 |
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91 /** Append a character as a two byte number. |
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92 */ |
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93 public void appendChar(int x) { |
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94 while (length + 1 >= elems.length) copy(elems.length * 2); |
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95 elems[length ] = (byte)((x >> 8) & 0xFF); |
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96 elems[length+1] = (byte)((x ) & 0xFF); |
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97 length = length + 2; |
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98 } |
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99 |
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100 /** Append an integer as a four byte number. |
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101 */ |
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102 public void appendInt(int x) { |
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103 while (length + 3 >= elems.length) copy(elems.length * 2); |
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104 elems[length ] = (byte)((x >> 24) & 0xFF); |
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105 elems[length+1] = (byte)((x >> 16) & 0xFF); |
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106 elems[length+2] = (byte)((x >> 8) & 0xFF); |
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107 elems[length+3] = (byte)((x ) & 0xFF); |
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108 length = length + 4; |
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109 } |
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110 |
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111 /** Append a long as an eight byte number. |
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112 */ |
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113 public void appendLong(long x) { |
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114 ByteArrayOutputStream buffer = new ByteArrayOutputStream(8); |
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115 DataOutputStream bufout = new DataOutputStream(buffer); |
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116 try { |
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117 bufout.writeLong(x); |
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118 appendBytes(buffer.toByteArray(), 0, 8); |
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119 } catch (IOException e) { |
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120 throw new AssertionError("write"); |
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121 } |
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122 } |
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123 |
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124 /** Append a float as a four byte number. |
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125 */ |
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126 public void appendFloat(float x) { |
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127 ByteArrayOutputStream buffer = new ByteArrayOutputStream(4); |
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128 DataOutputStream bufout = new DataOutputStream(buffer); |
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129 try { |
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130 bufout.writeFloat(x); |
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131 appendBytes(buffer.toByteArray(), 0, 4); |
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132 } catch (IOException e) { |
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133 throw new AssertionError("write"); |
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134 } |
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135 } |
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136 |
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137 /** Append a double as a eight byte number. |
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138 */ |
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139 public void appendDouble(double x) { |
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140 ByteArrayOutputStream buffer = new ByteArrayOutputStream(8); |
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141 DataOutputStream bufout = new DataOutputStream(buffer); |
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142 try { |
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143 bufout.writeDouble(x); |
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144 appendBytes(buffer.toByteArray(), 0, 8); |
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145 } catch (IOException e) { |
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146 throw new AssertionError("write"); |
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147 } |
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148 } |
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149 |
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150 /** Append a name. |
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151 */ |
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152 public void appendName(Name name) { |
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153 appendBytes(name.table.names, name.index, name.len); |
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154 } |
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155 |
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156 /** Reset to zero length. |
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157 */ |
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158 public void reset() { |
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159 length = 0; |
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160 } |
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161 |
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162 /** Convert contents to name. |
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163 */ |
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164 public Name toName(Name.Table names) { |
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165 return names.fromUtf(elems, 0, length); |
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166 } |
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167 } |