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#ifndef BYTEME_GZIP_FILE_WRITER_HPP
#define BYTEME_GZIP_FILE_WRITER_HPP
#include <stdexcept>
#include <vector>
#include <string>
#include "Writer.hpp"
/**
* @file GzipFileWriter.hpp
*
* @brief Write a Gzip-compressed file.
*/
namespace byteme {
/**
* @brief Write uncompressed bytes to a Gzip-compressed file.
*
* This is basically a wrapper around Zlib's `gzFile` with correct closing and error checking.
*/
class GzipFileWriter : public Writer {
public:
/**
* @param path Path to the file.
* @param compression_level Gzip compression level.
* @param buffer_size Size of the internal buffer.
*/
GzipFileWriter(const char* path, int compression_level = 6, size_t buffer_size = 65536) : gz(path, "wb") {
if (gzbuffer(gz.handle, buffer_size)) {
throw std::runtime_error("failed to set the Gzip compression buffer");
}
if (gzsetparams(gz.handle, compression_level, Z_DEFAULT_STRATEGY) != Z_OK) {
throw std::runtime_error("failed to set the Gzip compression parameters");
}
}
/**
* @param path Path to the file.
* @param compression_level Gzip compression level.
* @param buffer_size Size of the buffer to use for reading.
*/
GzipFileWriter(const std::string& path, int compression_level = 6, size_t buffer_size = 65536) : GzipFileWriter(path.c_str(), compression_level, buffer_size) {}
public:
using Writer::write;
void write(const unsigned char* buffer, size_t n) {
if (n) {
size_t ok = gzwrite(gz.handle, buffer, n);
if (ok != n) {
throw std::runtime_error("failed to write to the Gzip-compressed file");
}
}
}
void finish() {
gz.closed = true;
if (gzclose(gz.handle) != Z_OK) {
throw std::runtime_error("failed to close the Gzip-compressed file after writing");
}
}
private:
SelfClosingGzFile gz;
};
}
#endif
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