01: /*
02: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
03: *
04: * This file is part of Resin(R) Open Source
05: *
06: * Each copy or derived work must preserve the copyright notice and this
07: * notice unmodified.
08: *
09: * Resin Open Source is free software; you can redistribute it and/or modify
10: * it under the terms of the GNU General Public License as published by
11: * the Free Software Foundation; either version 2 of the License, or
12: * (at your option) any later version.
13: *
14: * Resin Open Source is distributed in the hope that it will be useful,
15: * but WITHOUT ANY WARRANTY; without even the implied warranty of
16: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17: * of NON-INFRINGEMENT. See the GNU General Public License for more
18: * details.
19: *
20: * You should have received a copy of the GNU General Public License
21: * along with Resin Open Source; if not, write to the
22: *
23: * Free Software Foundation, Inc.
24: * 59 Temple Place, Suite 330
25: * Boston, MA 02111-1307 USA
26: *
27: * @author Scott Ferguson
28: */
29:
30: package com.caucho.db.index;
31:
32: /**
33: * Compares two keys.
34: */
35: public class BinaryKeyCompare extends KeyCompare {
36: /**
37: * Compares the key to the block data.
38: */
39: public int compare(byte[] keyBuffer, int keyOffset, byte[] block,
40: int offset, int length) {
41: int keyLen = keyBuffer[keyOffset] & 0xff;
42: int blockLen = block[offset] & 0xff;
43:
44: int end = keyLen;
45: if (blockLen < end)
46: end = blockLen;
47:
48: for (int i = 1; i <= end; i++) {
49: int ch1 = keyBuffer[keyOffset + i] & 0xff;
50: int ch2 = block[offset + i] & 0xff;
51:
52: if (ch1 < ch2)
53: return -1;
54: else if (ch2 < ch1)
55: return 1;
56: }
57:
58: if (keyLen == blockLen)
59: return 0;
60:
61: if (keyLen < blockLen)
62: return -1;
63: else if (blockLen < keyLen)
64: return 1;
65: else
66: return 0;
67: }
68:
69: public String toString(byte[] buffer, int offset, int length) {
70: StringBuilder sb = new StringBuilder();
71:
72: int keyLen = buffer[offset];
73:
74: for (int j = 0; j < keyLen; j++) {
75: int ch = buffer[offset + 1 + j] & 0xff;
76:
77: if (ch == 0)
78: break;
79:
80: if (ch < 0x80)
81: sb.append((char) ch);
82: else if ((ch & 0xe0) == 0xc0) {
83: int ch1 = buffer[offset + 1 + j] & 0xff;
84: sb.append((char) (((ch & 0x0f) << 6) + (ch & 0x3f)));
85: j++;
86: } else {
87: int ch2 = buffer[offset + 1 + j] & 0xff;
88: int ch3 = buffer[offset + 2 + j] & 0xff;
89: sb.append((char) (((ch & 0x0f) << 12)
90: + ((ch & 0x3f) << 6) + ((ch & 0x3f))));
91: j += 2;
92: }
93: }
94:
95: return sb.toString();
96: }
97: }
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