Pull cacheinvalidations code directory into chromium repo.

third_party/cacheinvalidation/src/google/cacheinvalidation/impl/digest-store.h

Index: third_party/cacheinvalidation/src/google/cacheinvalidation/impl/digest-store.h
diff --git a/third_party/cacheinvalidation/src/google/cacheinvalidation/impl/digest-store.h b/third_party/cacheinvalidation/src/google/cacheinvalidation/impl/digest-store.h
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+// Copyright 2012 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.
+
+// Interface for a store that allows objects to be added/removed along with the
+// ability to get the digest for the whole or partial set of those objects.
+
+#ifndef GOOGLE_CACHEINVALIDATION_IMPL_DIGEST_STORE_H_
+#define GOOGLE_CACHEINVALIDATION_IMPL_DIGEST_STORE_H_
+
+#include <vector>
+
+namespace invalidation {
+
+using INVALIDATION_STL_NAMESPACE::vector;
+
+template<typename ElementType>
+class DigestStore {
+ public:
+  virtual ~DigestStore() {}
+
+  /* Returns the number of elements. */
+  virtual int size() = 0;
+
+  /* Returns whether element is in the store. */
+  virtual bool Contains(const ElementType& element) = 0;
+
+  /* Returns a digest of the desired objects in 'digest'.
+   *
+   * NOTE: the digest computations MUST NOT depend on the order in which the
+   * elements were added.
+   */
+  virtual string GetDigest() = 0;
+
+  /* Stores iterators bounding the elements whose digest prefixes begin with the
+   * bit prefix digest_prefix.  prefix_len is the length of digest_prefix in
+   * bits, which may be less than digest_prefix.length (and may be 0). The
+   * implementing class can return *more* objects than what has been specified
+   * by digest_prefix, e.g., it could return all the objects in the store.
+   */
+  virtual void GetElements(const string& digest_prefix, int prefix_len,
+      vector<ObjectIdP>* result) = 0;
+
+  /* Adds element to the store. No-op if element is already present.
+   * Returns whether the element was added.
+   */
+  virtual bool Add(const ElementType& element) = 0;
+
+  /* Adds elements to the store. If any element in elements is already present,
+   * the addition is a no-op for that element. When the function returns,
+   * added_elements will have been modified to contain all the elements
+   * of elements that were not previously present.
+   */
+  virtual void Add(const vector<ElementType>& elements,
+      vector<ElementType>* added_elements) = 0;
+
+  /* Removes element from the store. No-op if element is not present.
+   * Returns whether the element was removed.
+   */
+  virtual bool Remove(const ElementType& element) = 0;
+
+  /* Remove elements from the store. If any element in element is not present,
+   * the removal is a no-op for that element.
+   * When the function returns, removed_elements will have been modified to
+   * contain all the elements of elements that were previously present
+   */
+  virtual void Remove(const vector<ElementType>& elements,
+      vector<ElementType>* removed_elements) = 0;
+
+  /* Removes all elements in this and stores them in elements. */
+  virtual void RemoveAll(vector<ElementType>* elements) = 0;
+
+  /* Returns a string representation of this digest store. */
+  virtual string ToString() = 0;
+};
+
+}  // namespace invalidation
+
+#endif  // GOOGLE_CACHEINVALIDATION_IMPL_DIGEST_STORE_H_