Add BufferWriter::AppendString

Change-Id: Id8a7d09fd76eeb95600e108c70c2e38ddd18a7ab

packager/media/base/buffer_writer.cc

@@ -55,6 +55,10 @@ void BufferWriter::AppendVector(const std::vector<uint8_t>& v) {
   buf_.insert(buf_.end(), v.begin(), v.end());
 }
 
+void BufferWriter::AppendString(const std::string& s) {
+  buf_.insert(buf_.end(), s.begin(), s.end());
+}
+
 void BufferWriter::AppendArray(const uint8_t* buf, size_t size) {
   buf_.insert(buf_.end(), buf, buf + size);
 }

packager/media/base/buffer_writer.h

@@ -48,6 +48,7 @@ class BufferWriter {
   void AppendNBytes(uint64_t v, size_t num_bytes);
 
   void AppendVector(const std::vector<uint8_t>& v);
+  void AppendString(const std::string& s);
   void AppendArray(const uint8_t* buf, size_t size);
   void AppendBuffer(const BufferWriter& buffer);
 

packager/media/base/buffer_writer_unittest.cc

@@ -110,6 +110,18 @@ TEST_F(BufferWriterTest, AppendVector) {
   ASSERT_EQ(v, data_read);
 }
 
+TEST_F(BufferWriterTest, AppendString) {
+  const char kTestData[] = "test_data";
+  writer_->AppendString(kTestData);
+  // -1 to remove the null terminating character.
+  ASSERT_EQ(strlen(kTestData), writer_->Size());
+
+  CreateReader();
+  std::string data_read;
+  ASSERT_TRUE(reader_->ReadToString(&data_read, strlen(kTestData)));
+  ASSERT_EQ(kTestData, data_read);
+}
+
 TEST_F(BufferWriterTest, AppendArray) {
   writer_->AppendArray(kuint8Array, sizeof(kuint8Array));
   ASSERT_EQ(sizeof(kuint8Array), writer_->Size());