From f157a5651c79a7a36e242af216a5d5b383ba8af2 Mon Sep 17 00:00:00 2001
From: Feng Xiao <xfxyjwf@gmail.com>
Date: Fri, 14 Nov 2014 11:50:31 -0800
Subject: Down-integrate from internal code base (C++ maps support).

---
 src/google/protobuf/map_field.cc | 113 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 src/google/protobuf/map_field.cc

(limited to 'src/google/protobuf/map_field.cc')

diff --git a/src/google/protobuf/map_field.cc b/src/google/protobuf/map_field.cc
new file mode 100644
index 00000000..74431628
--- /dev/null
+++ b/src/google/protobuf/map_field.cc
@@ -0,0 +1,113 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <google/protobuf/map_field.h>
+
+namespace google {
+namespace protobuf {
+namespace internal {
+
+MapFieldBase::~MapFieldBase() {
+  if (repeated_field_ != NULL) delete repeated_field_;
+}
+
+const RepeatedPtrFieldBase& MapFieldBase::GetRepeatedField() const {
+  SyncRepeatedFieldWithMap();
+  return *repeated_field_;
+}
+
+RepeatedPtrFieldBase* MapFieldBase::MutableRepeatedField() {
+  SyncRepeatedFieldWithMap();
+  SetRepeatedDirty();
+  return repeated_field_;
+}
+
+int MapFieldBase::SpaceUsedExcludingSelf() const {
+  mutex_.Lock();
+  int size = SpaceUsedExcludingSelfNoLock();
+  mutex_.Unlock();
+  return size;
+}
+
+int MapFieldBase::SpaceUsedExcludingSelfNoLock() const {
+  if (repeated_field_ != NULL) {
+    return repeated_field_->SpaceUsedExcludingSelf();
+  } else {
+    return 0;
+  }
+}
+
+void MapFieldBase::InitMetadataOnce() const {
+  GOOGLE_CHECK(entry_descriptor_ != NULL);
+  GOOGLE_CHECK(assign_descriptor_callback_ != NULL);
+  (*assign_descriptor_callback_)();
+}
+
+void MapFieldBase::SetMapDirty() { state_ = STATE_MODIFIED_MAP; }
+
+void MapFieldBase::SetRepeatedDirty() { state_ = STATE_MODIFIED_REPEATED; }
+
+void* MapFieldBase::MutableRepeatedPtrField() const { return repeated_field_; }
+
+void MapFieldBase::SyncRepeatedFieldWithMap() const {
+  Atomic32 state = google::protobuf::internal::NoBarrier_Load(&state_);
+  if (state == STATE_MODIFIED_MAP) {
+    mutex_.Lock();
+    // Double check state, because another thread may have seen the same state
+    // and done the synchronization before the current thread.
+    if (state_ == STATE_MODIFIED_MAP) {
+      SyncRepeatedFieldWithMapNoLock();
+      google::protobuf::internal::NoBarrier_Store(&state_, CLEAN);
+    }
+    mutex_.Unlock();
+  }
+}
+
+void MapFieldBase::SyncRepeatedFieldWithMapNoLock() const {
+  if (repeated_field_ == NULL) repeated_field_ = new RepeatedPtrField<Message>;
+}
+
+void MapFieldBase::SyncMapWithRepeatedField() const {
+  Atomic32 state = google::protobuf::internal::NoBarrier_Load(&state_);
+  if (state == STATE_MODIFIED_REPEATED) {
+    mutex_.Lock();
+    // Double check state, because another thread may have seen the same state
+    // and done the synchronization before the current thread.
+    if (state_ == STATE_MODIFIED_REPEATED) {
+      SyncMapWithRepeatedFieldNoLock();
+      google::protobuf::internal::NoBarrier_Store(&state_, CLEAN);
+    }
+    mutex_.Unlock();
+  }
+}
+
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google
-- 
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