Pull cacheinvalidations code directory into chromium repo.

third_party/cacheinvalidation/src/java/com/google/ipc/invalidation/util/Preconditions.java

+/*
+ * Copyright 2011 Google Inc.
+ *
+ * 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.ipc.invalidation.util;
+
+
+/**
+ * Precondition checkers modeled after {@link com.google.common.base.Preconditions}. Duplicated here
+ * to avoid the dependency on guava in Java client code.
+ */
+public class Preconditions {
+
+  /**
+   * Throws {@link NullPointerException} if the {@code reference} argument is
+   * {@code null}. Otherwise, returns {@code reference}.
+   */
+  public static <T> T checkNotNull(T reference) {
+    if (reference == null) {
+      throw new NullPointerException();
+    }
+    return reference;
+  }
+
+  /**
+   * Throws {@link NullPointerException} if the {@code reference} argument is
+   * {@code null}. Otherwise, returns {@code reference}.
+   */
+  public static <T> T checkNotNull(T reference, Object errorMessage) {
+    if (reference == null) {
+      throw new NullPointerException(String.valueOf(errorMessage));
+    }
+    return reference;
+  }
+
+  /** Throws {@link IllegalStateException} if the given {@code expression} is {@code false}. */
+  public static void checkState(boolean expression) {
+    if (!expression) {
+      throw new IllegalStateException();
+    }
+  }
+
+  /** Throws {@link IllegalStateException} if the given {@code expression} is {@code false}. */
+  public static void checkState(boolean expression, Object errorMessage) {
+    if (!expression) {
+      throw new IllegalStateException(String.valueOf(errorMessage));
+    }
+  }
+
+  /** Throws {@link IllegalArgumentException} if the given {@code expression} is {@code false}. */
+  public static void checkArgument(boolean expression) {
+    if (!expression) {
+      throw new IllegalArgumentException();
+    }
+  }
+
+  /** Throws {@link IllegalArgumentException} if the given {@code expression} is {@code false}. */
+  public static void checkArgument(boolean expression, Object errorMessage) {
+    if (!expression) {
+      throw new IllegalArgumentException(String.valueOf(errorMessage));
+    }
+  }
+
+  // Do not instantiate.
+  private Preconditions() {
+  }
+}