1 files changed, 121 insertions, 0 deletions
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/parser/CharArrayPool.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/parser/CharArrayPool.java
new file mode 100644
index 00000000000..0a0c6453c78
--- /dev/null
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/parser/CharArrayPool.java
@@ -0,0 +1,121 @@
+/*
+ * Created on May 28, 2004
+ *
+ * TODO To change the template for this generated file go to
+ * Window - Preferences - Java - Code Style - Code Templates
+ */
+package org.eclipse.cdt.core.parser;
+
+/**
+ * @author dschaefe
+ *
+ * TODO To change the template for this generated type comment go to
+ * Window - Preferences - Java - Code Style - Code Templates
+ */
+public class CharArrayPool {
+
+	private int currEntry = -1;
+	
+	// Hash table is twice the size of the others
+	private int[] hashTable;
+	private int[] nextTable;
+	private char[][] stringTable;
+	
+	public CharArrayPool(int tableSize) {
+		// make sure size is a power of 2
+		int size = 1;
+		while (size < tableSize)
+			size <<= 1;
+		
+		hashTable = new int[size << 1];
+		nextTable = new int[tableSize];
+		stringTable = new char[tableSize][];
+	}
+	
+	private final int hash(char[] source, int start, int length) {
+		return CharArrayUtils.hash(source, start, length) & (hashTable.length - 1);
+	}
+
+	private static final boolean equals(char[] str1, int start, int length, char[] str2) {
+		if (str2.length != length)
+			return false;
+		
+		int curr = start;
+		for (int i = 0; i < length; ++i)
+			if (str1[curr++] != str2[i])
+				return false;
+		
+		return true;
+	}
+	
+	private final char[] find(char[] source, int start, int length, int hash) {
+		int i = hashTable[hash] - 1;
+		
+		do {
+			char[] str = stringTable[i];
+			if (equals(source, start, length, str))
+				return str;
+			i = nextTable[i] - 1;
+		} while (i >= 0);
+		
+		return null;
+	}
+
+	// Removes the current entry
+	private final void remove() {
+		int hash = hash(stringTable[currEntry], 0, stringTable[currEntry].length);
+		int i = hashTable[hash] - 1;
+		if (i == currEntry)
+			// make my next the hash entry
+			hashTable[hash] = nextTable[currEntry];
+		else {
+			// remove me from the next list
+			int last;
+			do {
+				last = i;
+				i = nextTable[i] - 1;
+			} while (i != currEntry);
+			
+			nextTable[last] = nextTable[currEntry];
+		}
+		
+		stringTable[currEntry] = null;
+		nextTable[currEntry] = 0;
+	}
+	
+	private final void addHashed(char[] str, int hash) {
+		// First remove the existing string if there is one
+		if (++currEntry == stringTable.length)
+			currEntry = 0;
+		
+		if (stringTable[currEntry] != null)
+			remove();
+		
+		stringTable[currEntry] = str;
+
+		// Now add it to the hash table, insert into next entries as necessary
+		if (hashTable[hash] != 0)
+			nextTable[currEntry] = hashTable[hash];
+		hashTable[hash] = currEntry + 1;
+	}
+	
+	public final char[] add(char[] source, int start, int length) {
+		// do we have it already?
+		int hash = hash(source, start, length);
+		char[] result = null;
+		if (hashTable[hash] > 0)
+			result = find(source, start, length, hash);
+
+		// if not, add it
+		if (result == null) {
+			System.arraycopy(source, 0, result = new char[length], 0, length);
+			addHashed(result, hash);
+		}
+		
+		return result;
+	}
+	
+	public final char[] add(char[] source) {
+		return add(source, 0, source.length);
+	}
+}