Allow JSONWriter and JSONValueSerializer to ignore binary values when instructed to do so.

Design discussion is available here: http://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thread/967eb64325c24f9c

BUG=None
TEST=base_unittests


Review URL: http://codereview.chromium.org/8505033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@110021 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 126 insertions, 33 deletions

diff --git a/base/json/json_value_serializer.cc b/base/json/json_value_serializer.cc
index d667bc1..89f13a2 100644
--- a/base/json/json_value_serializer.cc
+++ b/base/json/json_value_serializer.cc
@@ -17,10 +17,24 @@ const char* JSONFileValueSerializer::kNoSuchFile = "File doesn't exist.";
 JSONStringValueSerializer::~JSONStringValueSerializer() {}
 
 bool JSONStringValueSerializer::Serialize(const Value& root) {
+  return SerializeInternal(root, false);
+}
+
+bool JSONStringValueSerializer::SerializeAndOmitBinaryValues(
+    const Value& root) {
+  return SerializeInternal(root, true);
+}
+
+bool JSONStringValueSerializer::SerializeInternal(const Value& root,
+                                                  bool omit_binary_values) {
   if (!json_string_ || initialized_with_const_string_)
     return false;
 
-  base::JSONWriter::Write(&root, pretty_print_, json_string_);
+  base::JSONWriter::WriteWithOptions(
+      &root,
+      pretty_print_,
+      omit_binary_values ? base::JSONWriter::OPTIONS_OMIT_BINARY_VALUES : 0,
+      json_string_);
   return true;
 }
 
@@ -38,10 +52,21 @@ Value* JSONStringValueSerializer::Deserialize(int* error_code,
 /******* File Serializer *******/
 
 bool JSONFileValueSerializer::Serialize(const Value& root) {
+  return SerializeInternal(root, false);
+}
+
+bool JSONFileValueSerializer::SerializeAndOmitBinaryValues(const Value& root) {
+  return SerializeInternal(root, true);
+}
+
+bool JSONFileValueSerializer::SerializeInternal(const Value& root,
+                                                bool omit_binary_values) {
   std::string json_string;
   JSONStringValueSerializer serializer(&json_string);
   serializer.set_pretty_print(true);
-  bool result = serializer.Serialize(root);
+  bool result = omit_binary_values ?
+      serializer.SerializeAndOmitBinaryValues(root) :
+      serializer.Serialize(root);
   if (!result)
     return false;
 
diff --git a/base/json/json_value_serializer.h b/base/json/json_value_serializer.h
index 650008e..037302a 100644
--- a/base/json/json_value_serializer.h
+++ b/base/json/json_value_serializer.h
@@ -39,7 +39,11 @@ class BASE_EXPORT JSONStringValueSerializer : public base::ValueSerializer {
   // Attempt to serialize the data structure represented by Value into
   // JSON.  If the return value is true, the result will have been written
   // into the string passed into the constructor.
-  virtual bool Serialize(const Value& root);
+  virtual bool Serialize(const Value& root) OVERRIDE;
+
+  // Equivalent to Serialize(root) except binary values are omitted from the
+  // output.
+  bool SerializeAndOmitBinaryValues(const Value& root);
 
   // Attempt to deserialize the data structure encoded in the string passed
   // in to the constructor into a structure of Value objects.  If the return
@@ -48,7 +52,8 @@ class BASE_EXPORT JSONStringValueSerializer : public base::ValueSerializer {
   // If |error_message| is non-null, it will be filled in with a formatted
   // error message including the location of the error if appropriate.
   // The caller takes ownership of the returned value.
-  virtual Value* Deserialize(int* error_code, std::string* error_message);
+  virtual Value* Deserialize(int* error_code, std::string* error_message)
+      OVERRIDE;
 
   void set_pretty_print(bool new_value) { pretty_print_ = new_value; }
   bool pretty_print() { return pretty_print_; }
@@ -58,6 +63,8 @@ class BASE_EXPORT JSONStringValueSerializer : public base::ValueSerializer {
   }
 
  private:
+  bool SerializeInternal(const Value& root, bool omit_binary_values);
+
   std::string* json_string_;
   bool initialized_with_const_string_;
   bool pretty_print_;  // If true, serialization will span multiple lines.
@@ -86,7 +93,11 @@ class BASE_EXPORT JSONFileValueSerializer : public base::ValueSerializer {
   // Attempt to serialize the data structure represented by Value into
   // JSON.  If the return value is true, the result will have been written
   // into the file whose name was passed into the constructor.
-  virtual bool Serialize(const Value& root);
+  virtual bool Serialize(const Value& root) OVERRIDE;
+
+  // Equivalent to Serialize(root) except binary values are omitted from the
+  // output.
+  bool SerializeAndOmitBinaryValues(const Value& root);
 
   // Attempt to deserialize the data structure encoded in the file passed
   // in to the constructor into a structure of Value objects.  If the return
@@ -95,7 +106,8 @@ class BASE_EXPORT JSONFileValueSerializer : public base::ValueSerializer {
   // If |error_message| is non-null, it will be filled in with a formatted
   // error message including the location of the error if appropriate.
   // The caller takes ownership of the returned value.
-  virtual Value* Deserialize(int* error_code, std::string* error_message);
+  virtual Value* Deserialize(int* error_code, std::string* error_message)
+      OVERRIDE;
 
   // This enum is designed to safely overlap with JSONReader::JsonParseError.
   enum JsonFileError {
@@ -117,6 +129,8 @@ class BASE_EXPORT JSONFileValueSerializer : public base::ValueSerializer {
   static const char* GetErrorMessageForCode(int error_code);
 
  private:
+  bool SerializeInternal(const Value& root, bool omit_binary_values);
+
   FilePath json_file_path_;
 
   // A wrapper for file_util::ReadFileToString which returns a non-zero
diff --git a/base/json/json_writer.cc b/base/json/json_writer.cc
index 6531772..f457331 100644
--- a/base/json/json_writer.cc
+++ b/base/json/json_writer.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -26,19 +26,21 @@ const char* JSONWriter::kEmptyArray = "[]";
 void JSONWriter::Write(const Value* const node,
                        bool pretty_print,
                        std::string* json) {
-  WriteWithOptionalEscape(node, pretty_print, true, json);
+  WriteWithOptions(node, pretty_print, 0, json);
 }
 
 /* static */
-void JSONWriter::WriteWithOptionalEscape(const Value* const node,
-                                         bool pretty_print,
-                                         bool escape,
-                                         std::string* json) {
+void JSONWriter::WriteWithOptions(const Value* const node,
+                                  bool pretty_print,
+                                  int options,
+                                  std::string* json) {
   json->clear();
   // Is there a better way to estimate the size of the output?
   json->reserve(1024);
   JSONWriter writer(pretty_print, json);
-  writer.BuildJSONString(node, 0, escape);
+  bool escape = !(options & OPTIONS_DO_NOT_ESCAPE);
+  bool omit_binary_values = !!(options & OPTIONS_OMIT_BINARY_VALUES);
+  writer.BuildJSONString(node, 0, escape, omit_binary_values);
   if (pretty_print)
     json->append(kPrettyPrintLineEnding);
 }
@@ -51,7 +53,8 @@ JSONWriter::JSONWriter(bool pretty_print, std::string* json)
 
 void JSONWriter::BuildJSONString(const Value* const node,
                                  int depth,
-                                 bool escape) {
+                                 bool escape,
+                                 bool omit_binary_values) {
   switch (node->GetType()) {
     case Value::TYPE_NULL:
       json_string_->append("null");
@@ -122,16 +125,21 @@ void JSONWriter::BuildJSONString(const Value* const node,
 
         const ListValue* list = static_cast<const ListValue*>(node);
         for (size_t i = 0; i < list->GetSize(); ++i) {
+          Value* value = NULL;
+          bool result = list->Get(i, &value);
+          DCHECK(result);
+
+          if (omit_binary_values && value->GetType() == Value::TYPE_BINARY) {
+            continue;
+          }
+
           if (i != 0) {
             json_string_->append(",");
             if (pretty_print_)
               json_string_->append(" ");
           }
 
-          Value* value = NULL;
-          bool result = list->Get(i, &value);
-          DCHECK(result);
-          BuildJSONString(value, depth, escape);
+          BuildJSONString(value, depth, escape, omit_binary_values);
         }
 
         if (pretty_print_)
@@ -151,16 +159,20 @@ void JSONWriter::BuildJSONString(const Value* const node,
         for (DictionaryValue::key_iterator key_itr = dict->begin_keys();
              key_itr != dict->end_keys();
              ++key_itr) {
+          Value* value = NULL;
+          bool result = dict->GetWithoutPathExpansion(*key_itr, &value);
+          DCHECK(result);
+
+          if (omit_binary_values && value->GetType() == Value::TYPE_BINARY) {
+            continue;
+          }
+
           if (key_itr != dict->begin_keys()) {
             json_string_->append(",");
             if (pretty_print_)
               json_string_->append(kPrettyPrintLineEnding);
           }
 
-          Value* value = NULL;
-          bool result = dict->GetWithoutPathExpansion(*key_itr, &value);
-          DCHECK(result);
-
           if (pretty_print_)
             IndentLine(depth + 1);
           AppendQuotedString(*key_itr);
@@ -169,7 +181,7 @@ void JSONWriter::BuildJSONString(const Value* const node,
           } else {
             json_string_->append(":");
           }
-          BuildJSONString(value, depth + 1, escape);
+          BuildJSONString(value, depth + 1, escape, omit_binary_values);
         }
 
         if (pretty_print_) {
@@ -182,8 +194,15 @@ void JSONWriter::BuildJSONString(const Value* const node,
         break;
       }
 
+    case Value::TYPE_BINARY:
+      {
+        if (!omit_binary_values) {
+          NOTREACHED() << "Cannot serialize binary value.";
+        }
+        break;
+      }
+
     default:
-      // TODO(jhughes): handle TYPE_BINARY
       NOTREACHED() << "unknown json type";
   }
 }
diff --git a/base/json/json_writer.h b/base/json/json_writer.h
index 1eeecb9..88c7d58 100644
--- a/base/json/json_writer.h
+++ b/base/json/json_writer.h
@@ -17,6 +17,17 @@ class Value;
 
 class BASE_EXPORT JSONWriter {
  public:
+  enum Options {
+    // Do not escape the string, preserving its UTF8 characters. It is useful
+    // if you can pass the resulting string to the JSON parser in binary form
+    // (as UTF8).
+    OPTIONS_DO_NOT_ESCAPE = 1 << 0,
+
+    // For values of binary type, the value (and key if within a dictionary)
+    // will be omitted from the output.
+    OPTIONS_OMIT_BINARY_VALUES = 1 << 1
+  };
+
   // Given a root node, generates a JSON string and puts it into |json|.
   // If |pretty_print| is true, return a slightly nicer formated json string
   // (pads with whitespace to help readability).  If |pretty_print| is false,
@@ -27,13 +38,10 @@ class BASE_EXPORT JSONWriter {
   static void Write(const Value* const node, bool pretty_print,
                     std::string* json);
 
-  // Same as above, but has an option to not escape the string, preserving its
-  // UTF8 characters. It is useful if you can pass resulting string to the
-  // JSON parser in binary form (as UTF8).
-  static void WriteWithOptionalEscape(const Value* const node,
-                                      bool pretty_print,
-                                      bool escape,
-                                      std::string* json);
+  // Same as above but with |options| which is a bunch of JSONWriter::Options
+  // bitwise ORed together.
+  static void WriteWithOptions(const Value* const node, bool pretty_print,
+                               int options, std::string* json);
 
   // A static, constant JSON string representing an empty array.  Useful
   // for empty JSON argument passing.
@@ -44,7 +52,8 @@ class BASE_EXPORT JSONWriter {
 
   // Called recursively to build the JSON string.  Whe completed, value is
   // json_string_ will contain the JSON.
-  void BuildJSONString(const Value* const node, int depth, bool escape);
+  void BuildJSONString(const Value* const node, int depth, bool escape,
+                       bool ignore_binary_values);
 
   // Appends a quoted, escaped, version of (UTF-8) str to json_string_.
   void AppendQuotedString(const std::string& str);
diff --git a/base/json/json_writer_unittest.cc b/base/json/json_writer_unittest.cc
index 6d7714b..5d44c02 100644
--- a/base/json/json_writer_unittest.cc
+++ b/base/json/json_writer_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -93,6 +93,32 @@ TEST(JSONWriterTest, Writing) {
   period_dict3.SetWithoutPathExpansion("a.b", Value::CreateIntegerValue(1));
   JSONWriter::Write(&period_dict3, false, &output_js);
   ASSERT_EQ("{\"a\":{\"b\":2},\"a.b\":1}", output_js);
+
+  // Test ignoring binary values.
+  root = BinaryValue::CreateWithCopiedBuffer("asdf", 4);
+  JSONWriter::WriteWithOptions(root, false,
+                               JSONWriter::OPTIONS_OMIT_BINARY_VALUES,
+                               &output_js);
+  ASSERT_TRUE(output_js.empty());
+  delete root;
+
+  ListValue binary_list;
+  binary_list.Append(Value::CreateIntegerValue(5));
+  binary_list.Append(BinaryValue::CreateWithCopiedBuffer("asdf", 4));
+  binary_list.Append(Value::CreateIntegerValue(2));
+  JSONWriter::WriteWithOptions(&binary_list, false,
+                               JSONWriter::OPTIONS_OMIT_BINARY_VALUES,
+                               &output_js);
+  ASSERT_EQ("[5,2]", output_js);
+
+  DictionaryValue binary_dict;
+  binary_dict.Set("a", Value::CreateIntegerValue(5));
+  binary_dict.Set("b", BinaryValue::CreateWithCopiedBuffer("asdf", 4));
+  binary_dict.Set("c", Value::CreateIntegerValue(2));
+  JSONWriter::WriteWithOptions(&binary_dict, false,
+                               JSONWriter::OPTIONS_OMIT_BINARY_VALUES,
+                               &output_js);
+  ASSERT_EQ("{\"a\":5,\"c\":2}", output_js);
 }
 
 }  // namespace base