Update hashCode to hash the entire message

lib/generated_message.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of protobuf;
 
 typedef GeneratedMessage CreateBuilderFunc();
 typedef Object MakeDefaultFunc();
 typedef ProtobufEnum ValueOfFunc(int value);
 
@@ skipping 261 matching lines @@
     if (other is! GeneratedMessage) return false;
 
     GeneratedMessage o = other;
     if (o.info_ != info_) return false;
     if (!_areMapsEqual(o._fieldValues, _fieldValues)) return false;
     if (o.unknownFields != unknownFields) return false;
 
     return true;
   }
 
-  int get hashCode => _fieldValues.hashCode;
+  int get hashCode {
+    int hash;
+
+    void hashEnumList(PbList enums) {
+      enums.forEach((enum) {
+        hash = (31 * hash + enum.value) & 0x3fffffff;
+      });
+    }
+
+    void hashFields() {
+      for (int tagNumber in sorted(_fieldValues.keys)) {
+        if (!hasField(tagNumber)) continue;
+        var value = _fieldValues[tagNumber];
+        hash = ((37 * hash) + tagNumber) & 0x3fffffff;
+        int fieldType = _getFieldType(tagNumber);
+        if (_toBaseFieldType(fieldType) != _ENUM_BIT) {
+          hash = ((53 * hash) + value.hashCode) & 0x3fffffff;
+        } else if ((fieldType & _REPEATED_BIT) != 0) {
+          hashEnumList(value);
+        } else {
+          hash = ((53 * hash) + value.value) & 0x3fffffff;
+        }
+      }
+    }
+
+    // Generate hash.
+    hash = 41;
+    // Hash with descriptor.
+    hash = ((19 * hash) + info_.hashCode) & 0x3fffffff;
+    // Hash with fields.
+    hashFields();
+    // Hash with unknown fields.
+    hash = ((29 * hash) + unknownFields.hashCode) & 0x3fffffff;
+    return hash;
+  }
 
   String toString() => _toString('');
 
   String _toString(String indent) {
     StringBuffer s = new StringBuffer();
     void renderValue(key, value) {
       if (value is GeneratedMessage) {
         s.write('${indent}${key}: {\n');
         s.write(value._toString('$indent  '));
         s.write('${indent}}\n');
@@ skipping 72 matching lines @@
         iocReadFunc(list.add);
       }
     }
 
     void readPackable(int wireType, int tagNumber, var readFunc) {
       readPackableIoc(wireType, tagNumber,
           (var assigner) => assigner(readFunc()));
     }
 
     bool wireTypeMatch(int tagNumber, int fieldType, int wireType) {
-      int fieldDataType = fieldType &
-          ~(_REQUIRED_BIT | _REPEATED_BIT | _PACKED_BIT);
-      switch (fieldDataType) {
+      switch (_toBaseFieldType(fieldType)) {
         case _BOOL_BIT:
         case _ENUM_BIT:
         case _INT32_BIT:
         case _INT64_BIT:
         case _SINT32_BIT:
         case _SINT64_BIT:
         case _UINT32_BIT:
         case _UINT64_BIT:
           return wireType == WIRETYPE_VARINT ||
               wireType == WIRETYPE_LENGTH_DELIMITED;
@@ skipping 276 matching lines @@
    * represented as their integer value.
    */
   String writeToJson() => JSON.encode(_toMap());
 
   // Merge fields from a previously decoded JSON object.
   GeneratedMessage _mergeFromJson(
       Map<String, dynamic> json,
       ExtensionRegistry extensionRegistry) {
     // Extract a value from its JSON representation.
     convertJsonValue(var value, int tagNumber, int fieldType) {
-      // Mask off 'required', 'repeated' and 'packed' bits to obtain base type.
-      fieldType &= ~(_REQUIRED_BIT | _REPEATED_BIT | _PACKED_BIT);
-
       String expectedType; // for exception message
-      switch (fieldType) {
+      switch (_toBaseFieldType(fieldType)) {
       case _BOOL_BIT:
         if (value is bool) {
           return value;
         } else if (value is String) {
           if (value == 'true') {
             return true;
           } else if (value == 'false') {
             return false;
           }
         }
@@ skipping 301 matching lines @@
    * or from a known extension.  If the type is unknown, [null] is returned.
    */
   int _getFieldType(int tagNumber) {
     int type = info_.fieldType(tagNumber);
     if (type == null && _extensions.containsKey(tagNumber)) {
       type = _extensions[tagNumber].type;
     }
     return type;
   }
 
+  /**
+   * Returns the type associated with a given tag number, either from the
+   * [BuilderInfo] associated with this [GeneratedMessage],
+   * or from a known extension.  If the type is unknown, [null] is returned.
+   */
+  int _getBaseFieldType(int tagNumber) {
+    int type = info_.fieldType(tagNumber);
+    if (type == null && _extensions.containsKey(tagNumber)) {
+      type = _extensions[tagNumber].type;
+    }
+    return type;
+  }
+
+  /*
+   * Returns the base field type without any of the required, repeated
+   * and packed bits.
+   */
+  int _toBaseFieldType(int fieldType) {
+    return fieldType & ~(_REQUIRED_BIT | _REPEATED_BIT | _PACKED_BIT);
+  }
+
   GeneratedMessage _getEmptyMessage(
       int tagNumber, ExtensionRegistry extensionRegistry) {
     CreateBuilderFunc subBuilderFunc = info_.subBuilder(tagNumber);
     if (subBuilderFunc == null && extensionRegistry != null) {
       subBuilderFunc = extensionRegistry.getExtension(info_.messageName,
           tagNumber).subBuilder;
     }
     return subBuilderFunc();
   }
 
@@ skipping 174 matching lines @@
               _generateMessage(tagNumber, value, 'not a GeneratedMessage'));
         }
         break;
       default:
         throw new ArgumentError(
             _generateMessage(tagNumber, value, 'field has unknown type '
             '$fieldType'));
     }
   }
 }