Parsing for Maps in JavaNano

1 files changed, 97 insertions, 0 deletions

diff --git a/javanano/src/main/java/com/google/protobuf/nano/MapUtil.java b/javanano/src/main/java/com/google/protobuf/nano/MapUtil.java
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+++ b/javanano/src/main/java/com/google/protobuf/nano/MapUtil.java
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 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.
+
+package com.google.protobuf.nano;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Utility class for maps support.
+ */
+public final class MapUtil {
+  public static interface MapFactory {
+    <K, V> Map<K, V> forMap(Map<K, V> oldMap);
+  }
+  public static void setMapFactory(MapFactory newMapFactory) {
+    mapFactory = newMapFactory;
+  }
+
+  private static class DefaultMapFactory implements MapFactory {
+    public <K, V> Map<K, V> forMap(Map<K, V> oldMap) {
+      if (oldMap == null) {
+        return new HashMap<K, V>();
+      }
+      return oldMap;
+    }
+  }
+  private static volatile MapFactory mapFactory = new DefaultMapFactory();
+
+  @SuppressWarnings("unchecked")
+  public static final <K, V> Map<K, V> mergeEntry(
+      Map<K, V> target, CodedInputByteBufferNano input,
+      int keyType, int valueType, V value,
+      int keyTag, int valueTag)
+      throws IOException {
+    target = mapFactory.forMap(target);
+    final int length = input.readRawVarint32();
+    final int oldLimit = input.pushLimit(length);
+    K key = null;
+    while (true) {
+      int tag = input.readTag();
+      if (tag == 0) {
+        break;
+      }
+      if (tag == keyTag) {
+        key = (K) input.readData(keyType);
+      } else if (tag == valueTag) {
+        if (valueType == InternalNano.TYPE_MESSAGE) {
+          input.readMessage((MessageNano) value);
+        } else {
+          value = (V) input.readData(valueType);
+        }
+      } else {
+        if (!input.skipField(tag)) {
+          break;
+        }
+      }
+    }
+    input.checkLastTagWas(0);
+    input.popLimit(oldLimit);
+
+    if (key != null) {
+      target.put(key, value);
+    }
+    return target;
+  }
+
+  private MapUtil() {}
+}