--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ * VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.db.impl.query;\r
+\r
+import gnu.trove.impl.hash.THash;\r
+\r
+import java.lang.reflect.Array;\r
+\r
+import org.simantics.db.impl.graph.ReadGraphImpl;\r
+\r
+\r
+/**\r
+ * An open addressed hashing implementation for Object types.\r
+ *\r
+ * Created: Sun Nov 4 08:56:06 2001\r
+ *\r
+ * @author Eric D. Friedman\r
+ * @version $Id: BinaryQueryHash.java,v 1.2 2008/03/14 11:38:53 tuoksk Exp $\r
+ */\r
+abstract public class BinaryQueryHash<Procedure> extends THash {\r
+ static final long serialVersionUID = -3461112548087185871L;\r
+\r
+ /** the set of Objects */\r
+ protected transient BinaryQuery<Procedure>[] _set;\r
+\r
+ protected final BinaryQuery<Procedure> REMOVED = new BinaryQuery<Procedure>(-1, -1) {\r
+\r
+ @Override\r
+ public void computeForEach(ReadGraphImpl graph, QueryProcessor provider, Object procedure, boolean store) {\r
+ throw new Error("Not possible!");\r
+ }\r
+\r
+ @Override\r
+ public void putEntry(QueryProcessor provider) {\r
+ throw new Error("Not possible!");\r
+ }\r
+\r
+ @Override\r
+ public BinaryQuery<Procedure> getEntry(QueryProcessor provider) {\r
+ throw new Error("Not possible!");\r
+ }\r
+\r
+ @Override\r
+ public void recompute(ReadGraphImpl graph, QueryProcessor provider) {\r
+ throw new Error("Not possible!");\r
+ }\r
+\r
+ @Override\r
+ public void removeEntry(QueryProcessor provider) {\r
+ throw new Error("Not possible!");\r
+ }\r
+\r
+// @Override\r
+// public ICacheEntry2 cachedEntry(Object provider) {\r
+// throw new Error("Not possible!");\r
+// }\r
+//\r
+// @Override\r
+// public void computeForEach(int callerThread, Object provider, ICacheEntry2 parent, Object procedure) {\r
+// throw new Error("Not possible!");\r
+// }\r
+\r
+ @Override\r
+ public int type() {\r
+ throw new Error("Not possible!");\r
+ }\r
+\r
+// @Override\r
+// public void reset() {\r
+// throw new Error("Not possible!");\r
+// }\r
+\r
+ @Override\r
+ public void performFromCache(ReadGraphImpl graph, QueryProcessor provider,\r
+ Procedure procedure) {\r
+ throw new Error("Not possible!");\r
+ }\r
+\r
+// @Override\r
+// public void performFromCache(int callerThread, Object provider,\r
+// Object procedure) {\r
+// throw new Error("Not possible!");\r
+// }\r
+\r
+ @Override\r
+ public void performFromCache(ReadGraphImpl graph, Object provider,\r
+ Object procedure) {\r
+ throw new Error("Not possible!");\r
+ }\r
+ \r
+ };\r
+\r
+ /**\r
+ * Creates a new <code>TObjectHash</code> instance with the\r
+ * default capacity and load factor.\r
+ */\r
+ public BinaryQueryHash() {\r
+ super(DEFAULT_CAPACITY, 0.75f);\r
+ }\r
+\r
+ public int capacity() {\r
+ return _set.length;\r
+ }\r
+\r
+ protected void removeAt(int index) {\r
+ _set[index] = REMOVED;\r
+ super.removeAt(index);\r
+ }\r
+\r
+ /**\r
+ * initializes the Object set of this hash table.\r
+ *\r
+ * @param initialCapacity an <code>int</code> value\r
+ * @return an <code>int</code> value\r
+ */\r
+ @SuppressWarnings("unchecked")\r
+ protected int setUp(int initialCapacity) {\r
+ int capacity;\r
+\r
+ capacity = super.setUp(initialCapacity);\r
+ _set = (BinaryQuery[])Array.newInstance(BinaryQuery.class, capacity);\r
+ return capacity;\r
+ \r
+ }\r
+\r
+ final protected int index(final long id) {\r
+\r
+ final BinaryQuery<Procedure>[] set = _set;\r
+ final int length = set.length;\r
+ final int hash = ((31 * ((int)(id>>>32)) + (int)id) )& 0x7fffffff;\r
+ int index = hash % length;\r
+ BinaryQuery<Procedure> cur = set[index];\r
+\r
+ if ( cur == null ) return -1;\r
+\r
+ // NOTE: here it has to be REMOVED or FULL (some user-given value)\r
+ if ( cur == REMOVED || !(id == cur.id)) {\r
+ // see Knuth, p. 529\r
+ final int probe = 1 + (hash % (length - 2));\r
+\r
+ do {\r
+ index -= probe;\r
+ if (index < 0) {\r
+ index += length;\r
+ }\r
+ cur = set[index];\r
+ } while (cur != null\r
+ && (cur == REMOVED || !(id == cur.id)));\r
+ }\r
+\r
+ return cur == null ? -1 : index;\r
+ \r
+ }\r
+ \r
+\r
+ /**\r
+ * Locates the index at which <tt>obj</tt> can be inserted. if\r
+ * there is already a value equal()ing <tt>obj</tt> in the set,\r
+ * returns that value's index as <tt>-index - 1</tt>.\r
+ *\r
+ * @param obj an <code>Object</code> value\r
+ * @return the index of a FREE slot at which obj can be inserted\r
+ * or, if obj is already stored in the hash, the negative value of\r
+ * that index, minus 1: -index -1.\r
+ */\r
+ final protected int insertionIndex(final long id) {\r
+\r
+ final BinaryQuery<Procedure>[] set = _set;\r
+ final int length = set.length;\r
+ final int hash = (31 * ((int)(id>>>32)) + (int)id) & 0x7fffffff;\r
+ int index = hash % length;\r
+ BinaryQuery<Procedure> cur = set[index];\r
+\r
+ if (cur == null) {\r
+ return index; // empty, all done\r
+ } else if (cur != REMOVED && (id == cur.id)) {\r
+ return -index -1; // already stored\r
+ } else { // already FULL or REMOVED, must probe\r
+ // compute the double hash\r
+ final int probe = 1 + (hash % (length - 2));\r
+\r
+ // if the slot we landed on is FULL (but not removed), probe\r
+ // until we find an empty slot, a REMOVED slot, or an element\r
+ // equal to the one we are trying to insert.\r
+ // finding an empty slot means that the value is not present\r
+ // and that we should use that slot as the insertion point;\r
+ // finding a REMOVED slot means that we need to keep searching,\r
+ // however we want to remember the offset of that REMOVED slot\r
+ // so we can reuse it in case a "new" insertion (i.e. not an update)\r
+ // is possible.\r
+ // finding a matching value means that we've found that our desired\r
+ // key is already in the table\r
+ if (cur != REMOVED) {\r
+ // starting at the natural offset, probe until we find an\r
+ // offset that isn't full.\r
+ do {\r
+ index -= probe;\r
+ if (index < 0) {\r
+ index += length;\r
+ }\r
+ cur = set[index];\r
+ } while (cur != null\r
+ && cur != REMOVED\r
+ && ! (id == cur.id));\r
+ }\r
+\r
+ // if the index we found was removed: continue probing until we\r
+ // locate a free location or an element which equal()s the\r
+ // one we have.\r
+ if (cur == REMOVED) {\r
+ int firstRemoved = index;\r
+ while (cur != null\r
+ && (cur == REMOVED || ! (id == cur.id))) {\r
+ index -= probe;\r
+ if (index < 0) {\r
+ index += length;\r
+ }\r
+ cur = set[index];\r
+ }\r
+ // NOTE: cur cannot == REMOVED in this block\r
+ return (cur != null) ? -index -1 : firstRemoved;\r
+ }\r
+ // if it's full, the key is already stored\r
+ // NOTE: cur cannot equal REMOVE here (would have retuned already (see above)\r
+ return (cur != null) ? -index -1 : index;\r
+ }\r
+ }\r
+\r
+ /**\r
+ * Convenience methods for subclasses to use in throwing exceptions about\r
+ * badly behaved user objects employed as keys. We have to throw an\r
+ * IllegalArgumentException with a rather verbose message telling the\r
+ * user that they need to fix their object implementation to conform\r
+ * to the general contract for java.lang.Object.\r
+ *\r
+ * @param o1 the first of the equal elements with unequal hash codes.\r
+ * @param o2 the second of the equal elements with unequal hash codes.\r
+ * @exception IllegalArgumentException the whole point of this method.\r
+ */\r
+ protected final void throwObjectContractViolation(Object o1, Object o2)\r
+ throws IllegalArgumentException {\r
+ throw new IllegalArgumentException("Equal objects must have equal hashcodes. "\r
+ + "During rehashing, Trove discovered that "\r
+ + "the following two objects claim to be "\r
+ + "equal (as in java.lang.Object.equals()) "\r
+ + "but their hashCodes (or those calculated by "\r
+ + "your TObjectHashingStrategy) are not equal."\r
+ + "This violates the general contract of "\r
+ + "java.lang.Object.hashCode(). See bullet point two "\r
+ + "in that method's documentation. "\r
+ + "object #1 =" + o1 + " object #1 hash = " + o1.hashCode() + " object #1 id = " + System.identityHashCode(o1)\r
+ + "; object #2 =" + o2 + " object #2 hash = " + o2.hashCode() + " object #2 id = " + System.identityHashCode(o2));\r
+ }\r
+} // TObjectHash\r
Code Review / simantics / platform.git / blobdiff