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Diffstat (limited to 'android/guava/src/com/google/common/base/SmallCharMatcher.java')
-rw-r--r--android/guava/src/com/google/common/base/SmallCharMatcher.java146
1 files changed, 0 insertions, 146 deletions
diff --git a/android/guava/src/com/google/common/base/SmallCharMatcher.java b/android/guava/src/com/google/common/base/SmallCharMatcher.java
deleted file mode 100644
index 1e565c858..000000000
--- a/android/guava/src/com/google/common/base/SmallCharMatcher.java
+++ /dev/null
@@ -1,146 +0,0 @@
-/*
- * Copyright (C) 2012 The Guava Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
- * in compliance with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software distributed under the License
- * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
- * or implied. See the License for the specific language governing permissions and limitations under
- * the License.
- */
-
-package com.google.common.base;
-
-import com.google.common.annotations.GwtIncompatible;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.CharMatcher.NamedFastMatcher;
-import java.util.BitSet;
-
-/**
- * An immutable version of CharMatcher for smallish sets of characters that uses a hash table with
- * linear probing to check for matches.
- *
- * @author Christopher Swenson
- */
-@GwtIncompatible // no precomputation is done in GWT
-final class SmallCharMatcher extends NamedFastMatcher {
- static final int MAX_SIZE = 1023;
- private final char[] table;
- private final boolean containsZero;
- private final long filter;
-
- private SmallCharMatcher(char[] table, long filter, boolean containsZero, String description) {
- super(description);
- this.table = table;
- this.filter = filter;
- this.containsZero = containsZero;
- }
-
- private static final int C1 = 0xcc9e2d51;
- private static final int C2 = 0x1b873593;
-
- /*
- * This method was rewritten in Java from an intermediate step of the Murmur hash function in
- * http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp, which contained the
- * following header:
- *
- * MurmurHash3 was written by Austin Appleby, and is placed in the public domain. The author
- * hereby disclaims copyright to this source code.
- */
- static int smear(int hashCode) {
- return C2 * Integer.rotateLeft(hashCode * C1, 15);
- }
-
- private boolean checkFilter(int c) {
- return 1 == (1 & (filter >> c));
- }
-
- // This is all essentially copied from ImmutableSet, but we have to duplicate because
- // of dependencies.
-
- // Represents how tightly we can pack things, as a maximum.
- private static final double DESIRED_LOAD_FACTOR = 0.5;
-
- /**
- * Returns an array size suitable for the backing array of a hash table that uses open addressing
- * with linear probing in its implementation. The returned size is the smallest power of two that
- * can hold setSize elements with the desired load factor.
- */
- @VisibleForTesting
- static int chooseTableSize(int setSize) {
- if (setSize == 1) {
- return 2;
- }
- // Correct the size for open addressing to match desired load factor.
- // Round up to the next highest power of 2.
- int tableSize = Integer.highestOneBit(setSize - 1) << 1;
- while (tableSize * DESIRED_LOAD_FACTOR < setSize) {
- tableSize <<= 1;
- }
- return tableSize;
- }
-
- static CharMatcher from(BitSet chars, String description) {
- // Compute the filter.
- long filter = 0;
- int size = chars.cardinality();
- boolean containsZero = chars.get(0);
- // Compute the hash table.
- char[] table = new char[chooseTableSize(size)];
- int mask = table.length - 1;
- for (int c = chars.nextSetBit(0); c != -1; c = chars.nextSetBit(c + 1)) {
- // Compute the filter at the same time.
- filter |= 1L << c;
- int index = smear(c) & mask;
- while (true) {
- // Check for empty.
- if (table[index] == 0) {
- table[index] = (char) c;
- break;
- }
- // Linear probing.
- index = (index + 1) & mask;
- }
- }
- return new SmallCharMatcher(table, filter, containsZero, description);
- }
-
- @Override
- public boolean matches(char c) {
- if (c == 0) {
- return containsZero;
- }
- if (!checkFilter(c)) {
- return false;
- }
- int mask = table.length - 1;
- int startingIndex = smear(c) & mask;
- int index = startingIndex;
- do {
- if (table[index] == 0) { // Check for empty.
- return false;
- } else if (table[index] == c) { // Check for match.
- return true;
- } else { // Linear probing.
- index = (index + 1) & mask;
- }
- // Check to see if we wrapped around the whole table.
- } while (index != startingIndex);
- return false;
- }
-
- @Override
- void setBits(BitSet table) {
- if (containsZero) {
- table.set(0);
- }
- for (char c : this.table) {
- if (c != 0) {
- table.set(c);
- }
- }
- }
-}