001: /* Copyright (c) 1995-2000, The Hypersonic SQL Group.
002: * All rights reserved.
003: *
004: * Redistribution and use in source and binary forms, with or without
005: * modification, are permitted provided that the following conditions are met:
006: *
007: * Redistributions of source code must retain the above copyright notice, this
008: * list of conditions and the following disclaimer.
009: *
010: * Redistributions in binary form must reproduce the above copyright notice,
011: * this list of conditions and the following disclaimer in the documentation
012: * and/or other materials provided with the distribution.
013: *
014: * Neither the name of the Hypersonic SQL Group nor the names of its
015: * contributors may be used to endorse or promote products derived from this
016: * software without specific prior written permission.
017: *
018: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
019: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
020: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
021: * ARE DISCLAIMED. IN NO EVENT SHALL THE HYPERSONIC SQL GROUP,
022: * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
023: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
024: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025: * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
026: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028: * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029: *
030: * This software consists of voluntary contributions made by many individuals
031: * on behalf of the Hypersonic SQL Group.
032: *
033: *
034: * For work added by the HSQL Development Group:
035: *
036: * Copyright (c) 2001-2005, The HSQL Development Group
037: * All rights reserved.
038: *
039: * Redistribution and use in source and binary forms, with or without
040: * modification, are permitted provided that the following conditions are met:
041: *
042: * Redistributions of source code must retain the above copyright notice, this
043: * list of conditions and the following disclaimer.
044: *
045: * Redistributions in binary form must reproduce the above copyright notice,
046: * this list of conditions and the following disclaimer in the documentation
047: * and/or other materials provided with the distribution.
048: *
049: * Neither the name of the HSQL Development Group nor the names of its
050: * contributors may be used to endorse or promote products derived from this
051: * software without specific prior written permission.
052: *
053: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
054: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
055: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
056: * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
057: * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
058: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
059: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
060: * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
061: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
062: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
063: * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
064: */
065:
066: package org.hsqldb;
067:
068: // fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)
069: // fredt@users 20020920 - path 1.7.1 - refactoring to cut mamory footprint
070: // fredt@users 20021205 - path 1.7.2 - enhancements
071: // fredt@users 20021215 - doc 1.7.2 - javadoc comments
072:
073: /**
074: * Text table node implementation.<p>
075: * Nodes for the AVL tree are all built and kept in memory while the actual
076: * row data is accessed via TextCache from disk.<p>
077: * This differs from MemoryNode by maintaining an integral pointer for the
078: * Row data instead of a Java reference.
079: *
080: * New class based on Hypersonic SQL code.
081: *
082: * @author fredt@users
083: * @version 1.8.0
084: * @since 1.7.1
085: */
086: class PointerNode extends BaseMemoryNode {
087:
088: int iData = NO_POS;
089: private Table tTable;
090: private Node nPrimary; // node of key / primary index for this row
091:
092: PointerNode(CachedRow r, int id) {
093:
094: tTable = r.getTable();
095: iData = r.iPos;
096: nPrimary = r.nPrimaryNode == null ? this : r.nPrimaryNode;
097: }
098:
099: void delete() {
100:
101: super .delete();
102:
103: nPrimary = null;
104: tTable = null;
105: }
106:
107: int getKey() {
108: return iData;
109: }
110:
111: Row getRow() throws HsqlException {
112:
113: if (iData == NO_POS) {
114: return null;
115: }
116:
117: CachedRow r = tTable.getRow(iData, nPrimary);
118:
119: return r;
120: }
121:
122: Object[] getData() throws HsqlException {
123:
124: if (Trace.DOASSERT) {
125: Trace.doAssert(iBalance != -2);
126: }
127:
128: return getRow().getData();
129: }
130: }
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