gzip_compression.hpp
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#ifndef OSMIUM_IO_GZIP_COMPRESSION_HPP
#define OSMIUM_IO_GZIP_COMPRESSION_HPP
/*
This file is part of Osmium (http://osmcode.org/libosmium).
Copyright 2013-2016 Jochen Topf <jochen@topf.org> and others (see README).
Boost Software License - Version 1.0 - August 17th, 2003
Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:
The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/
#include <stdexcept>
#include <string>
#include <errno.h>
#include <zlib.h>
#include <osmium/io/compression.hpp>
#include <osmium/io/error.hpp>
#include <osmium/io/file_compression.hpp>
#include <osmium/io/writer_options.hpp>
#include <osmium/util/cast.hpp>
#include <osmium/util/compatibility.hpp>
namespace osmium {
struct gzip_error : public io_error {
int gzip_error_code;
int system_errno;
gzip_error(const std::string& what, int error_code) :
io_error(what),
gzip_error_code(error_code),
system_errno(error_code == Z_ERRNO ? errno : 0) {
}
}; // struct gzip_error
namespace io {
namespace detail {
OSMIUM_NORETURN inline void throw_gzip_error(gzFile gzfile, const char* msg, int zlib_error = 0) {
std::string error("gzip error: ");
error += msg;
error += ": ";
int errnum = zlib_error;
if (zlib_error) {
error += std::to_string(zlib_error);
} else {
error += ::gzerror(gzfile, &errnum);
}
throw osmium::gzip_error(error, errnum);
}
} // namespace detail
class GzipCompressor : public Compressor {
int m_fd;
gzFile m_gzfile;
public:
explicit GzipCompressor(int fd, fsync sync) :
Compressor(sync),
m_fd(dup(fd)),
m_gzfile(::gzdopen(fd, "w")) {
if (!m_gzfile) {
detail::throw_gzip_error(m_gzfile, "write initialization failed");
}
}
~GzipCompressor() noexcept final {
try {
close();
} catch (...) {
// Ignore any exceptions because destructor must not throw.
}
}
void write(const std::string& data) final {
if (!data.empty()) {
int nwrite = ::gzwrite(m_gzfile, data.data(), static_cast_with_assert<unsigned int>(data.size()));
if (nwrite == 0) {
detail::throw_gzip_error(m_gzfile, "write failed");
}
}
}
void close() final {
if (m_gzfile) {
int result = ::gzclose(m_gzfile);
m_gzfile = nullptr;
if (result != Z_OK) {
detail::throw_gzip_error(m_gzfile, "write close failed", result);
}
if (do_fsync()) {
osmium::io::detail::reliable_fsync(m_fd);
}
osmium::io::detail::reliable_close(m_fd);
}
}
}; // class GzipCompressor
class GzipDecompressor : public Decompressor {
gzFile m_gzfile;
public:
explicit GzipDecompressor(int fd) :
Decompressor(),
m_gzfile(::gzdopen(fd, "r")) {
if (!m_gzfile) {
detail::throw_gzip_error(m_gzfile, "read initialization failed");
}
}
~GzipDecompressor() noexcept final {
try {
close();
} catch (...) {
// Ignore any exceptions because destructor must not throw.
}
}
std::string read() final {
std::string buffer(osmium::io::Decompressor::input_buffer_size, '\0');
int nread = ::gzread(m_gzfile, const_cast<char*>(buffer.data()), static_cast_with_assert<unsigned int>(buffer.size()));
if (nread < 0) {
detail::throw_gzip_error(m_gzfile, "read failed");
}
buffer.resize(static_cast<std::string::size_type>(nread));
return buffer;
}
void close() final {
if (m_gzfile) {
int result = ::gzclose(m_gzfile);
m_gzfile = nullptr;
if (result != Z_OK) {
detail::throw_gzip_error(m_gzfile, "read close failed", result);
}
}
}
}; // class GzipDecompressor
class GzipBufferDecompressor : public Decompressor {
const char* m_buffer;
size_t m_buffer_size;
z_stream m_zstream;
public:
GzipBufferDecompressor(const char* buffer, size_t size) :
m_buffer(buffer),
m_buffer_size(size),
m_zstream() {
m_zstream.next_in = reinterpret_cast<unsigned char*>(const_cast<char*>(buffer));
m_zstream.avail_in = static_cast_with_assert<unsigned int>(size);
int result = inflateInit2(&m_zstream, MAX_WBITS | 32);
if (result != Z_OK) {
std::string message("gzip error: decompression init failed: ");
if (m_zstream.msg) {
message.append(m_zstream.msg);
}
throw osmium::gzip_error(message, result);
}
}
~GzipBufferDecompressor() noexcept final {
try {
close();
} catch (...) {
// Ignore any exceptions because destructor must not throw.
}
}
std::string read() final {
std::string output;
if (m_buffer) {
const size_t buffer_size = 10240;
output.append(buffer_size, '\0');
m_zstream.next_out = reinterpret_cast<unsigned char*>(const_cast<char*>(output.data()));
m_zstream.avail_out = buffer_size;
int result = inflate(&m_zstream, Z_SYNC_FLUSH);
if (result != Z_OK) {
m_buffer = nullptr;
m_buffer_size = 0;
}
if (result != Z_OK && result != Z_STREAM_END) {
std::string message("gzip error: inflate failed: ");
if (m_zstream.msg) {
message.append(m_zstream.msg);
}
throw osmium::gzip_error(message, result);
}
output.resize(static_cast<unsigned long>(m_zstream.next_out - reinterpret_cast<const unsigned char*>(output.data())));
}
return output;
}
void close() final {
inflateEnd(&m_zstream);
}
}; // class GzipBufferDecompressor
namespace detail {
// we want the register_compression() function to run, setting
// the variable is only a side-effect, it will never be used
const bool registered_gzip_compression = osmium::io::CompressionFactory::instance().register_compression(osmium::io::file_compression::gzip,
[](int fd, fsync sync) { return new osmium::io::GzipCompressor(fd, sync); },
[](int fd) { return new osmium::io::GzipDecompressor(fd); },
[](const char* buffer, size_t size) { return new osmium::io::GzipBufferDecompressor(buffer, size); }
);
// dummy function to silence the unused variable warning from above
inline bool get_registered_gzip_compression() noexcept {
return registered_gzip_compression;
}
} // namespace detail
} // namespace io
} // namespace osmium
#endif // OSMIUM_IO_GZIP_COMPRESSION_HPP
osmium::io::GzipCompressor::m_gzfile
gzFile m_gzfile
Definition: gzip_compression.hpp:99
osmium::io::GzipBufferDecompressor
Definition: gzip_compression.hpp:189
osmium::gzip_error::gzip_error
gzip_error(const std::string &what, int error_code)
Definition: gzip_compression.hpp:69
osmium::io::GzipDecompressor::m_gzfile
gzFile m_gzfile
Definition: gzip_compression.hpp:147
OSMIUM_NORETURN
#define OSMIUM_NORETURN
Definition: compatibility.hpp:41
osmium::io::GzipCompressor
Definition: gzip_compression.hpp:96
osmium::io::GzipBufferDecompressor::m_zstream
z_stream m_zstream
Definition: gzip_compression.hpp:193
osmium::io::CompressionFactory::instance
static CompressionFactory & instance()
Definition: compression.hpp:151
osmium::io::Decompressor::input_buffer_size
static constexpr unsigned int input_buffer_size
Definition: compression.hpp:91
osmium::io::GzipCompressor::GzipCompressor
GzipCompressor(int fd, fsync sync)
Definition: gzip_compression.hpp:103
osmium::io::GzipBufferDecompressor::m_buffer_size
size_t m_buffer_size
Definition: gzip_compression.hpp:192
osmium::io::GzipDecompressor
Definition: gzip_compression.hpp:145
file_compression.hpp
osmium::io::Decompressor
Definition: compression.hpp:87
osmium::io::GzipCompressor::m_fd
int m_fd
Definition: gzip_compression.hpp:98
osmium::io::GzipBufferDecompressor::GzipBufferDecompressor
GzipBufferDecompressor(const char *buffer, size_t size)
Definition: gzip_compression.hpp:197
osmium::io::GzipBufferDecompressor::~GzipBufferDecompressor
~GzipBufferDecompressor() noexceptfinal
Definition: gzip_compression.hpp:213
osmium::io::GzipDecompressor::~GzipDecompressor
~GzipDecompressor() noexceptfinal
Definition: gzip_compression.hpp:159
osmium
Namespace for everything in the Osmium library.
Definition: assembler.hpp:59
osmium::io::GzipBufferDecompressor::m_buffer
const char * m_buffer
Definition: gzip_compression.hpp:191
detail
Definition: attr.hpp:298
compression.hpp
osmium::io::GzipBufferDecompressor::close
void close() final
Definition: gzip_compression.hpp:250
osmium::io::GzipCompressor::~GzipCompressor
~GzipCompressor() noexceptfinal
Definition: gzip_compression.hpp:112
osmium::io::fsync
fsync
Definition: writer_options.hpp:51
osmium::io::GzipCompressor::close
void close() final
Definition: gzip_compression.hpp:129
osmium::io_error
Definition: error.hpp:44
osmium::gzip_error::system_errno
int system_errno
Definition: gzip_compression.hpp:67
osmium::gzip_error
Definition: gzip_compression.hpp:64
cast.hpp
osmium::io::GzipDecompressor::read
std::string read() final
Definition: gzip_compression.hpp:167
error.hpp
osmium::gzip_error::gzip_error_code
int gzip_error_code
Definition: gzip_compression.hpp:66
osmium::io::GzipDecompressor::GzipDecompressor
GzipDecompressor(int fd)
Definition: gzip_compression.hpp:151
osmium::io::Compressor
Definition: compression.hpp:62
osmium::io::GzipCompressor::write
void write(const std::string &data) final
Definition: gzip_compression.hpp:120
osmium::io::CompressionFactory::register_compression
bool register_compression(osmium::io::file_compression compression, create_compressor_type create_compressor, create_decompressor_type_fd create_decompressor_fd, create_decompressor_type_buffer create_decompressor_buffer)
Definition: compression.hpp:156
osmium::io::file_compression::gzip
writer_options.hpp
osmium::io::GzipBufferDecompressor::read
std::string read() final
Definition: gzip_compression.hpp:221
compatibility.hpp
osmium::io::GzipDecompressor::close
void close() final
Definition: gzip_compression.hpp:177