1 files changed, 108 insertions, 0 deletions

diff --git a/mtp/ffs/MtpStringBuffer.cpp b/mtp/ffs/MtpStringBuffer.cpp
new file mode 100644
index 000000000..e2302df75
--- /dev/null
+++ b/mtp/ffs/MtpStringBuffer.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *		http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "MtpStringBuffer"
+
+#include <codecvt>
+#include <locale>
+#include <string>
+#include <vector>
+
+#include "MtpDataPacket.h"
+#include "MtpStringBuffer.h"
+
+namespace {
+
+std::wstring_convert<std::codecvt_utf8_utf16<char16_t>,char16_t> gConvert;
+
+static std::string utf16ToUtf8(std::u16string input_str) {
+	return gConvert.to_bytes(input_str);
+}
+
+static std::u16string utf8ToUtf16(std::string input_str) {
+	return gConvert.from_bytes(input_str);
+}
+
+} // namespace
+
+MtpStringBuffer::MtpStringBuffer(const char* src)
+{
+	set(src);
+}
+
+MtpStringBuffer::MtpStringBuffer(const uint16_t* src)
+{
+	set(src);
+}
+
+MtpStringBuffer::MtpStringBuffer(const MtpStringBuffer& src)
+{
+	mString = src.mString;
+}
+
+void MtpStringBuffer::set(const char* src) {
+	mString = std::string(src);
+}
+
+void MtpStringBuffer::set(const uint16_t* src) {
+	mString = utf16ToUtf8(std::u16string((const char16_t*)src));
+}
+
+bool MtpStringBuffer::readFromPacket(MtpDataPacket* packet) {
+	uint8_t count;
+	if (!packet->getUInt8(count))
+		return false;
+	if (count == 0)
+		return true;
+
+	std::vector<char16_t> buffer(count);
+	for (int i = 0; i < count; i++) {
+		uint16_t ch;
+		if (!packet->getUInt16(ch))
+			return false;
+		buffer[i] = ch;
+	}
+	if (buffer[count-1] != '\0') {
+		MTPE("Mtp string not null terminated\n");
+		return false;
+	}
+	mString = utf16ToUtf8(std::u16string(buffer.data()));
+	return true;
+}
+
+void MtpStringBuffer::writeToPacket(MtpDataPacket* packet) const {
+	std::u16string src16 = utf8ToUtf16(mString);
+	int count = src16.length();
+
+	if (count == 0) {
+		packet->putUInt8(0);
+		return;
+	}
+	packet->putUInt8(std::min(count + 1, MTP_STRING_MAX_CHARACTER_NUMBER));
+
+	int i = 0;
+	for (char16_t &c : src16) {
+		if (i == MTP_STRING_MAX_CHARACTER_NUMBER - 1) {
+			// Leave a slot for null termination.
+			MTPD("Mtp truncating long string\n");
+			break;
+		}
+		packet->putUInt16(c);
+		i++;
+	}
+	// only terminate with zero if string is not empty
+	packet->putUInt16(0);
+}