150 lines
4.7 KiB
C++
150 lines
4.7 KiB
C++
#include "ZlibDecompressor.h"
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#include <algorithm>
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namespace ZlibCpp {
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ZlibDecompressor::ZlibDecompressor(DataFormat format)
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: format_(format), finished_(false) {
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Initialize(format);
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}
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ZlibDecompressor::~ZlibDecompressor() { if (initialized_) { Cleanup(); } }
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void ZlibDecompressor::Initialize(DataFormat format) {
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if (initialized_) {
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Cleanup();
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}
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format_ = format;
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finished_ = false;
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// 计算窗口位数
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int windowBits = 15; // 默认窗口大小
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if (format == DataFormat::Gzip) {
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windowBits += 16; // Gzip格式
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} else if (format == DataFormat::Raw) {
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windowBits = -windowBits; // 原始deflate格式
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}
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int result = inflateInit2(&stream_, windowBits);
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CheckResult(result, "inflateInit2");
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initialized_ = true;
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}
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void ZlibDecompressor::Reset() {
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if (!initialized_) {
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throw ZlibStreamException("解压缩器未初始化");
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}
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int result = inflateReset(&stream_);
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CheckResult(result, "inflateReset");
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finished_ = false;
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}
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std::vector<uint8_t> ZlibDecompressor::Decompress(const std::vector<uint8_t>& input, bool flush) {
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return Decompress(input.data(), input.size(), flush);
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}
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std::vector<uint8_t> ZlibDecompressor::Decompress(const uint8_t* input, size_t input_size, bool flush) {
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if (finished_) {
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throw ZlibStreamException("解压缩器已完成，无法继续解压缩");
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}
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int flush_mode = flush ? Z_SYNC_FLUSH : Z_NO_FLUSH;
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return DecompressInternal(input, input_size, flush_mode);
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}
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std::vector<uint8_t> ZlibDecompressor::Finish() {
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if (finished_) {
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return {};
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}
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finished_ = true;
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return DecompressInternal(nullptr, 0, Z_FINISH);
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}
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std::vector<uint8_t> ZlibDecompressor::DecompressInternal(const uint8_t* input, size_t input_size, int flush_mode) {
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if (!initialized_) {
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throw ZlibStreamException("解压缩器未初始化");
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}
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std::vector<uint8_t> output;
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const size_t buffer_size = 8192; // 8KB缓冲区
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uint8_t buffer[buffer_size];
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stream_.next_in = const_cast<Bytef*>(input);
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stream_.avail_in = static_cast<uInt>(input_size);
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do {
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stream_.next_out = buffer;
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stream_.avail_out = buffer_size;
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int result = inflate(&stream_, flush_mode);
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// 处理需要字典的情况
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if (result == Z_NEED_DICT) {
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throw ZlibDataException("需要字典进行解压缩");
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}
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if (result != Z_OK && result != Z_STREAM_END && result != Z_BUF_ERROR) {
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CheckResult(result, "inflate");
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}
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size_t produced = buffer_size - stream_.avail_out;
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if (produced > 0) {
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size_t old_size = output.size();
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output.resize(old_size + produced);
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std::copy(buffer, buffer + produced, output.begin() + old_size);
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}
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// 如果返回Z_STREAM_END，表示解压缩完成
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if (result == Z_STREAM_END) {
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finished_ = true;
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break;
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}
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} while (stream_.avail_out == 0); // 当输出缓冲区被填满时继续
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return output;
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}
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std::vector<uint8_t> ZlibDecompressor::DecompressData(const std::vector<uint8_t>& input, DataFormat format) {
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ZlibDecompressor decompressor(format);
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auto result = decompressor.Decompress(input);
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auto final = decompressor.Finish();
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result.insert(result.end(), final.begin(), final.end());
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return result;
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}
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std::string ZlibDecompressor::DecompressString(const std::vector<uint8_t>& input, DataFormat format) {
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auto data = DecompressData(input, format);
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return std::string(data.begin(), data.end());
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}
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void ZlibDecompressor::SetDictionary(const std::vector<uint8_t>& dictionary) {
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if (!initialized_) {
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throw ZlibStreamException("解压缩器未初始化");
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}
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int result = inflateSetDictionary(&stream_, dictionary.data(),
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static_cast<uInt>(dictionary.size()));
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CheckResult(result, "inflateSetDictionary");
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}
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bool ZlibDecompressor::IsFinished() const {
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return finished_;
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}
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DataFormat ZlibDecompressor::GetFormat() const {
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return format_;
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}
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void ZlibDecompressor::Cleanup() {
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if (initialized_) {
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inflateEnd(&stream_);
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initialized_ = false;
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}
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}
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} // namespace ZlibCpp
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