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1
11 package org.eclipse.core.internal.indexing;
12
13
16 public class Buffer {
17 protected byte[] contents;
18 private static final byte[] ZEROES = new byte[1024];
19
20
24 public Buffer(byte[] contents) {
25 this.contents = contents;
26 }
27
28
31 public Buffer(int n) {
32 contents = new byte[n];
33 }
34
35
38 public Buffer(Insertable anObject) {
39 this.contents = anObject.toByteArray();
40 }
41
42 public void clear() {
43 clear(contents, 0, contents.length);
44 }
45
46 private static void clear(byte[] buffer, int offset, int length) {
47 int n = length;
48 int p = offset;
49 while (n > 0) {
50 int m = Math.min(ZEROES.length, n);
51 System.arraycopy(ZEROES, 0, buffer, p, m);
52 p += m;
53 n -= m;
54 }
55 }
56
57 public void clear(int offset, int length) {
58 clear(contents, offset, length);
59 }
60
61 private static int compare(byte[] buffer1, int offset1, int length1, byte[] buffer2, int offset2, int length2) {
62 if (length1 < length2) {
63 return -compare(buffer2, offset2, length2, buffer1, offset1, length1);
64 }
65 for (int i = 0; i < length2; i++) {
66 int j1 = buffer1[offset1 + i] & 255;
67 int j2 = buffer2[offset2 + i] & 255;
68 if (j1 > j2)
69 return 1;
70 if (j1 < j2)
71 return -1;
72 }
73 if (length1 > length2)
74 return 1;
75 return 0;
76 }
77
78 public static int compare(Buffer buffer1, int offset1, int length1, Buffer buffer2, int offset2, int length2) {
79 return compare(buffer1.contents, offset1, length1, buffer2.contents, offset2, length2);
80 }
81
82 public void copyInternal(int fromOffset, int toOffset, int length) {
83 System.arraycopy(contents, fromOffset, contents, toOffset, length);
84 }
85
86 public void copyTo(byte[] buffer) {
87 int n = Math.min(buffer.length, contents.length);
88 System.arraycopy(contents, 0, buffer, 0, n);
89 }
90
91 public void copyFrom(byte[] buffer) {
92 int n = Math.min(buffer.length, contents.length);
93 System.arraycopy(buffer, 0, contents, 0, n);
94 }
95
96 public byte[] get() {
97 return get(0, contents.length);
98 }
99
100 public byte[] get(int offset, int length) {
101 byte[] result = new byte[length];
102 System.arraycopy(contents, offset, result, 0, length);
103 return result;
104 }
105
106 public Field getField(int offset, int length) {
107 return new Field(this, offset, length);
108 }
109
110 public byte getByte(int offset) {
111 return contents[offset];
112 }
113
114 public int getInt(int offset, int length) {
115 return (int) getLong(offset, length);
116 }
117
118 public int getUInt(int offset, int length) {
119 int shift = Math.max(0, 32 - (length * 8));
120 int mask = (-1 >>> shift) & Integer.MAX_VALUE;
121 return getInt(offset, length) & mask;
122 }
123
124 public long getLong(int offset, int length) {
125 if (length <= 0)
126 return 0;
127 long v = contents[offset];
128 for (int i = offset + 1; i < offset + length; i++) {
129 v = (v << 8) | (contents[i] & 255);
130 }
131 return v;
132 }
133
134 public byte[] getByteArray() {
135 return contents;
136 }
137
138 public int length() {
139 return contents.length;
140 }
141
142 public void put(int offset, byte value) {
143 contents[offset] = value;
144 }
145
146 public void put(int offset, byte[] source) {
147 System.arraycopy(source, 0, contents, offset, source.length);
148 }
149
150 public void put(int offset, int length, byte[] source) {
151 int n = Math.min(length, source.length);
152 System.arraycopy(source, 0, contents, offset, n);
153 }
154
155 public void put(int offset, int length, long n) {
156 long v = n;
157 int i = offset + length;
158 while (i > offset) {
159 i--;
160 contents[i] = (byte) v;
161 v = (v >>> 8);
162 }
163 }
164
165 public void put(int offset, int length, int n) {
166 put(offset, length, (long) n);
167 }
168
169 public void put(int offset, Insertable source) {
170 put(offset, source.toByteArray());
171 }
172
173 }
174 |
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