1/* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#define LOG_TAG "MtpStringBuffer" 18 19#include <codecvt> 20#include <locale> 21#include <string> 22#include <vector> 23 24#include "MtpDataPacket.h" 25#include "MtpStringBuffer.h" 26 27namespace { 28 29std::wstring_convert<std::codecvt_utf8_utf16<char16_t>,char16_t> gConvert; 30 31static std::string utf16ToUtf8(std::u16string input_str) { 32 return gConvert.to_bytes(input_str); 33} 34 35static std::u16string utf8ToUtf16(std::string input_str) { 36 return gConvert.from_bytes(input_str); 37} 38 39} // namespace 40 41namespace android { 42 43MtpStringBuffer::MtpStringBuffer(const char* src) 44{ 45 set(src); 46} 47 48MtpStringBuffer::MtpStringBuffer(const uint16_t* src) 49{ 50 set(src); 51} 52 53MtpStringBuffer::MtpStringBuffer(const MtpStringBuffer& src) 54{ 55 mString = src.mString; 56} 57 58void MtpStringBuffer::set(const char* src) { 59 mString = std::string(src); 60} 61 62void MtpStringBuffer::set(const uint16_t* src) { 63 mString = utf16ToUtf8(std::u16string((const char16_t*)src)); 64} 65 66bool MtpStringBuffer::readFromPacket(MtpDataPacket* packet) { 67 uint8_t count; 68 if (!packet->getUInt8(count)) 69 return false; 70 if (count == 0) 71 return true; 72 73 std::vector<char16_t> buffer(count); 74 for (int i = 0; i < count; i++) { 75 uint16_t ch; 76 if (!packet->getUInt16(ch)) 77 return false; 78 buffer[i] = ch; 79 } 80 if (buffer[count-1] != '\0') { 81 ALOGE("Mtp string not null terminated\n"); 82 return false; 83 } 84 mString = utf16ToUtf8(std::u16string(buffer.data())); 85 return true; 86} 87 88void MtpStringBuffer::writeToPacket(MtpDataPacket* packet) const { 89 std::u16string src16 = utf8ToUtf16(mString); 90 int count = src16.length(); 91 92 if (count == 0) { 93 packet->putUInt8(0); 94 return; 95 } 96 packet->putUInt8(std::min(count + 1, MTP_STRING_MAX_CHARACTER_NUMBER)); 97 98 int i = 0; 99 for (char16_t &c : src16) { 100 if (i == MTP_STRING_MAX_CHARACTER_NUMBER - 1) { 101 // Leave a slot for null termination. 102 ALOGI("Mtp truncating long string\n"); 103 break; 104 } 105 packet->putUInt16(c); 106 i++; 107 } 108 // only terminate with zero if string is not empty 109 packet->putUInt16(0); 110} 111 112} // namespace android 113