/*
* Copyright (C) 2016 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.
*/
#include "androidfw/Util.h"
#include <algorithm>
#include <string>
#include "utils/ByteOrder.h"
#include "utils/Unicode.h"
#ifdef _WIN32
#ifdef ERROR
#undef ERROR
#endif
#endif
namespace android {
namespace util {
void ReadUtf16StringFromDevice(const uint16_t* src, size_t len, std::string* out) {
char buf[5];
while (*src && len != 0) {
char16_t c = static_cast<char16_t>(dtohs(*src));
utf16_to_utf8(&c, 1, buf, sizeof(buf));
out->append(buf, strlen(buf));
++src;
--len;
}
}
std::u16string Utf8ToUtf16(StringPiece utf8) {
ssize_t utf16_length =
utf8_to_utf16_length(reinterpret_cast<const uint8_t*>(utf8.data()), utf8.length());
if (utf16_length <= 0) {
return {};
}
std::u16string utf16;
utf16.resize(utf16_length);
utf8_to_utf16(reinterpret_cast<const uint8_t*>(utf8.data()), utf8.length(), &*utf16.begin(),
utf16_length + 1);
return utf16;
}
std::string Utf16ToUtf8(StringPiece16 utf16) {
ssize_t utf8_length = utf16_to_utf8_length(utf16.data(), utf16.length());
if (utf8_length <= 0) {
return {};
}
std::string utf8;
utf8.resize(utf8_length);
utf16_to_utf8(utf16.data(), utf16.length(), &*utf8.begin(), utf8_length + 1);
return utf8;
}
std::string Utf8ToModifiedUtf8(std::string_view utf8) {
// Java uses Modified UTF-8 which only supports the 1, 2, and 3 byte formats of UTF-8. To encode
// 4 byte UTF-8 codepoints, Modified UTF-8 allows the use of surrogate pairs in the same format
// of CESU-8 surrogate pairs. Calculate the size of the utf8 string with all 4 byte UTF-8
// codepoints replaced with 2 3 byte surrogate pairs
size_t modified_size = 0;
const size_t size = utf8.size();
for (size_t i = 0; i < size; i++) {
if (((uint8_t)utf8[i] >> 4) == 0xF) {
modified_size += 6;
i += 3;
} else {
modified_size++;
}
}
// Early out if no 4 byte codepoints are found
if (size == modified_size) {
return std::string(utf8);
}
std::string output;
output.reserve(modified_size);
for (size_t i = 0; i < size; i++) {
if (((uint8_t)utf8[i] >> 4) == 0xF) {
int32_t codepoint = utf32_from_utf8_at(utf8.data(), size, i, nullptr);
// Calculate the high and low surrogates as UTF-16 would
int32_t high = ((codepoint - 0x10000) / 0x400) + 0xD800;
int32_t low = ((codepoint - 0x10000) % 0x400) + 0xDC00;
// Encode each surrogate in UTF-8
output.push_back((char)(0xE4 | ((high >> 12) & 0xF)));
output.push_back((char)(0x80 | ((high >> 6) & 0x3F)));
output.push_back((char)(0x80 | (high & 0x3F)));
output.push_back((char)(0xE4 | ((low >> 12) & 0xF)));
output.push_back((char)(0x80 | ((low >> 6) & 0x3F)));
output.push_back((char)(0x80 | (low & 0x3F)));
i += 3;
} else {
output.push_back(utf8[i]);
}
}
return output;
}
std::string ModifiedUtf8ToUtf8(std::string_view modified_utf8) {
// The UTF-8 representation will have a byte length less than or equal to the Modified UTF-8
// representation.
std::string output;
output.reserve(modified_utf8.size());
size_t index = 0;
const size_t modified_size = modified_utf8.size();
while (index < modified_size) {
size_t next_index;
int32_t high_surrogate =
utf32_from_utf8_at(modified_utf8.data(), modified_size, index, &next_index);
if (high_surrogate < 0) {
return {};
}
// Check that the first codepoint is within the high surrogate range
if (high_surrogate >= 0xD800 && high_surrogate <= 0xDB7F) {
int32_t low_surrogate =
utf32_from_utf8_at(modified_utf8.data(), modified_size, next_index, &next_index);
if (low_surrogate < 0) {
return {};
}
// Check that the second codepoint is within the low surrogate range
if (low_surrogate >= 0xDC00 && low_surrogate <= 0xDFFF) {
const char32_t codepoint =
(char32_t)(((high_surrogate - 0xD800) * 0x400) + (low_surrogate - 0xDC00) + 0x10000);
// The decoded codepoint should represent a 4 byte, UTF-8 character
const size_t utf8_length = (size_t)utf32_to_utf8_length(&codepoint, 1);
if (utf8_length != 4) {
return {};
}
// Encode the UTF-8 representation of the codepoint into the string
const size_t start_index = output.size();
output.resize(start_index + utf8_length);
char* start = &output[start_index];
utf32_to_utf8((char32_t*)&codepoint, 1, start, utf8_length + 1);
index = next_index;
continue;
}
}
// Append non-surrogate pairs to the output string
for (size_t i = index; i < next_index; i++) {
output.push_back(modified_utf8[i]);
}
index = next_index;
}
return output;
}
template <class Func>
static std::vector<std::string> SplitAndTransform(StringPiece str, char sep, Func&& f) {
std::vector<std::string> parts;
const StringPiece::const_iterator end = std::end(str);
StringPiece::const_iterator start = std::begin(str);
StringPiece::const_iterator current;
do {
current = std::find(start, end, sep);
parts.emplace_back(StringPiece(start, current - start));
std::string& part = parts.back();
std::transform(part.begin(), part.end(), part.begin(), f);
start = current + 1;
} while (current != end);
return parts;
}
std::vector<std::string> SplitAndLowercase(StringPiece str, char sep) {
return SplitAndTransform(str, sep, [](char c) { return ::tolower(c); });
}
std::unique_ptr<uint8_t[]> Copy(const BigBuffer& buffer) {
auto data = std::unique_ptr<uint8_t[]>(new uint8_t[buffer.size()]);
uint8_t* p = data.get();
for (const auto& block : buffer) {
memcpy(p, block.buffer.get(), block.size);
p += block.size;
}
return data;
}
StringPiece16 GetString16(const android::ResStringPool& pool, size_t idx) {
if (auto str = pool.stringAt(idx); str.ok()) {
return *str;
}
return StringPiece16();
}
std::string GetString(const android::ResStringPool& pool, size_t idx) {
if (auto str = pool.string8At(idx); str.ok()) {
return ModifiedUtf8ToUtf8(*str);
}
return Utf16ToUtf8(GetString16(pool, idx));
}
} // namespace util
} // namespace android