Initial Jack import.

Change-Id: I953cf0a520195a7187d791b2885848ad0d5a9b43

1 files changed, 148 insertions, 0 deletions

diff --git a/guava/src/com/google/common/hash/AbstractCompositeHashFunction.java b/guava/src/com/google/common/hash/AbstractCompositeHashFunction.java
new file mode 100644
index 0000000..e0b074f
--- /dev/null
+++ b/guava/src/com/google/common/hash/AbstractCompositeHashFunction.java
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2011 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.hash;
+
+import java.nio.charset.Charset;
+
+/**
+ * An abstract composition of multiple hash functions. {@linkplain #newHasher()} delegates to the
+ * {@code Hasher} objects of the delegate hash functions, and in the end, they are used by
+ * {@linkplain #makeHash(Hasher[])} that constructs the final {@code HashCode}.
+ *
+ * @author Dimitris Andreou
+ */
+abstract class AbstractCompositeHashFunction extends AbstractStreamingHashFunction {
+  final HashFunction[] functions;
+
+  AbstractCompositeHashFunction(HashFunction... functions) {
+    this.functions = functions;
+  }
+
+  /**
+   * Constructs a {@code HashCode} from the {@code Hasher} objects of the functions. Each of them
+   * has consumed the entire input and they are ready to output a {@code HashCode}. The order of
+   * the hashers are the same order as the functions given to the constructor.
+   */
+  // this could be cleaner if it passed HashCode[], but that would create yet another array...
+  /* protected */ abstract HashCode makeHash(Hasher[] hashers);
+
+  @Override
+  public Hasher newHasher() {
+    final Hasher[] hashers = new Hasher[functions.length];
+    for (int i = 0; i < hashers.length; i++) {
+      hashers[i] = functions[i].newHasher();
+    }
+    return new Hasher() {
+      @Override public Hasher putByte(byte b) {
+        for (Hasher hasher : hashers) {
+          hasher.putByte(b);
+        }
+        return this;
+      }
+
+      @Override public Hasher putBytes(byte[] bytes) {
+        for (Hasher hasher : hashers) {
+          hasher.putBytes(bytes);
+        }
+        return this;
+      }
+
+      @Override public Hasher putBytes(byte[] bytes, int off, int len) {
+        for (Hasher hasher : hashers) {
+          hasher.putBytes(bytes, off, len);
+        }
+        return this;
+      }
+
+      @Override public Hasher putShort(short s) {
+        for (Hasher hasher : hashers) {
+          hasher.putShort(s);
+        }
+        return this;
+      }
+
+      @Override public Hasher putInt(int i) {
+        for (Hasher hasher : hashers) {
+          hasher.putInt(i);
+        }
+        return this;
+      }
+
+      @Override public Hasher putLong(long l) {
+        for (Hasher hasher : hashers) {
+          hasher.putLong(l);
+        }
+        return this;
+      }
+
+      @Override public Hasher putFloat(float f) {
+        for (Hasher hasher : hashers) {
+          hasher.putFloat(f);
+        }
+        return this;
+      }
+
+      @Override public Hasher putDouble(double d) {
+        for (Hasher hasher : hashers) {
+          hasher.putDouble(d);
+        }
+        return this;
+      }
+
+      @Override public Hasher putBoolean(boolean b) {
+        for (Hasher hasher : hashers) {
+          hasher.putBoolean(b);
+        }
+        return this;
+      }
+
+      @Override public Hasher putChar(char c) {
+        for (Hasher hasher : hashers) {
+          hasher.putChar(c);
+        }
+        return this;
+      }
+
+      @Override public Hasher putString(CharSequence chars) {
+        for (Hasher hasher : hashers) {
+          hasher.putString(chars);
+        }
+        return this;
+      }
+
+      @Override public Hasher putString(CharSequence chars, Charset charset) {
+        for (Hasher hasher : hashers) {
+          hasher.putString(chars, charset);
+        }
+        return this;
+      }
+
+      @Override public <T> Hasher putObject(T instance, Funnel<? super T> funnel) {
+        for (Hasher hasher : hashers) {
+          hasher.putObject(instance, funnel);
+        }
+        return this;
+      }
+
+      @Override public HashCode hash() {
+        return makeHash(hashers);
+      }
+    };
+  }
+
+  private static final long serialVersionUID = 0L;
+}