cog/Frameworks/OpenMPT.old/OpenMPT/common/FileReader.h

1432 lines
41 KiB
C++

/*
* FileReader.h
* ------------
* Purpose: A basic class for transparent reading of memory-based files.
* Notes : (currently none)
* Authors: OpenMPT Devs
* The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
*/
#pragma once
#include "BuildSettings.h"
#include "mptStringBuffer.h"
#include "misc_util.h"
#include "Endianness.h"
#include "mptIO.h"
#include <algorithm>
#include <limits>
#include <vector>
#include <cstring>
#include "FileReaderFwd.h"
OPENMPT_NAMESPACE_BEGIN
// change to show warnings for functions which trigger pre-caching the whole file for unseekable streams
//#define FILEREADER_DEPRECATED [[deprecated]]
#define FILEREADER_DEPRECATED
class FileReaderTraitsMemory
{
public:
using off_t = FileDataContainerMemory::off_t;
using data_type = FileDataContainerMemory;
using ref_data_type = const FileDataContainerMemory &;
using shared_data_type = const FileDataContainerMemory &;
using value_data_type = FileDataContainerMemory;
static shared_data_type get_shared(const data_type & data) { return data; }
static ref_data_type get_ref(const data_type & data) { return data; }
static value_data_type make_data() { return mpt::const_byte_span(); }
static value_data_type make_data(mpt::const_byte_span data) { return data; }
static value_data_type make_chunk(shared_data_type data, off_t position, off_t size)
{
return mpt::as_span(data.GetRawData() + position, size);
}
};
class FileReaderTraitsStdStream
{
public:
using off_t = IFileDataContainer::off_t;
using data_type = std::shared_ptr<const IFileDataContainer>;
using ref_data_type = const IFileDataContainer &;
using shared_data_type = std::shared_ptr<const IFileDataContainer>;
using value_data_type = std::shared_ptr<const IFileDataContainer>;
static shared_data_type get_shared(const data_type & data) { return data; }
static ref_data_type get_ref(const data_type & data) { return *data; }
static value_data_type make_data() { return std::make_shared<FileDataContainerDummy>(); }
static value_data_type make_data(mpt::const_byte_span data) { return std::make_shared<FileDataContainerMemory>(data); }
static value_data_type make_chunk(shared_data_type data, off_t position, off_t size)
{
return std::static_pointer_cast<IFileDataContainer>(std::make_shared<FileDataContainerWindow>(data, position, size));
}
};
using FileReaderTraitsDefault = FileReaderTraitsStdStream;
namespace mpt
{
namespace FileReader
{
// Read a "T" object from the stream.
// If not enough bytes can be read, false is returned.
// If successful, the file cursor is advanced by the size of "T".
template <typename T, typename TFileCursor>
bool Read(TFileCursor &f, T &target)
{
// cppcheck false-positive
// cppcheck-suppress uninitvar
mpt::byte_span dst = mpt::as_raw_memory(target);
if(dst.size() != f.GetRaw(dst))
{
return false;
}
f.Skip(dst.size());
return true;
}
// Read some kind of integer in little-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename T, typename TFileCursor>
T ReadIntLE(TFileCursor &f)
{
static_assert(std::numeric_limits<T>::is_integer == true, "Target type is a not an integer");
typename mpt::make_le<T>::type target;
if(Read(f, target))
{
return target;
} else
{
return 0;
}
}
// Read some kind of integer in big-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename T, typename TFileCursor>
T ReadIntBE(TFileCursor &f)
{
static_assert(std::numeric_limits<T>::is_integer == true, "Target type is a not an integer");
typename mpt::make_be<T>::type target;
if(Read(f, target))
{
return target;
} else
{
return 0;
}
}
// Read a integer in little-endian format which has some of its higher bytes not stored in file.
// If successful, the file cursor is advanced by the given size.
template <typename T, typename TFileCursor>
T ReadTruncatedIntLE(TFileCursor &f, typename TFileCursor::off_t size)
{
static_assert(std::numeric_limits<T>::is_integer == true, "Target type is a not an integer");
MPT_ASSERT(sizeof(T) >= size);
if(size == 0)
{
return 0;
}
if(!f.CanRead(size))
{
return 0;
}
uint8 buf[sizeof(T)];
bool negative = false;
for(std::size_t i = 0; i < sizeof(T); ++i)
{
uint8 byte = 0;
if(i < size)
{
Read(f, byte);
negative = std::numeric_limits<T>::is_signed && ((byte & 0x80) != 0x00);
} else
{
// sign or zero extend
byte = negative ? 0xff : 0x00;
}
buf[i] = byte;
}
typename mpt::make_le<T>::type target;
std::memcpy(&target, buf, sizeof(T));
return target;
}
// Read a supplied-size little endian integer to a fixed size variable.
// The data is properly sign-extended when fewer bytes are stored.
// If more bytes are stored, higher order bytes are silently ignored.
// If successful, the file cursor is advanced by the given size.
template <typename T, typename TFileCursor>
T ReadSizedIntLE(TFileCursor &f, typename TFileCursor::off_t size)
{
static_assert(std::numeric_limits<T>::is_integer == true, "Target type is a not an integer");
if(size == 0)
{
return 0;
}
if(!f.CanRead(size))
{
return 0;
}
if(size < sizeof(T))
{
return ReadTruncatedIntLE<T>(f, size);
}
T retval = ReadIntLE<T>(f);
f.Skip(size - sizeof(T));
return retval;
}
// Read unsigned 32-Bit integer in little-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
uint32 ReadUint32LE(TFileCursor &f)
{
return ReadIntLE<uint32>(f);
}
// Read unsigned 32-Bit integer in big-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
uint32 ReadUint32BE(TFileCursor &f)
{
return ReadIntBE<uint32>(f);
}
// Read signed 32-Bit integer in little-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
int32 ReadInt32LE(TFileCursor &f)
{
return ReadIntLE<int32>(f);
}
// Read signed 32-Bit integer in big-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
int32 ReadInt32BE(TFileCursor &f)
{
return ReadIntBE<int32>(f);
}
// Read unsigned 16-Bit integer in little-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
uint16 ReadUint16LE(TFileCursor &f)
{
return ReadIntLE<uint16>(f);
}
// Read unsigned 16-Bit integer in big-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
uint16 ReadUint16BE(TFileCursor &f)
{
return ReadIntBE<uint16>(f);
}
// Read signed 16-Bit integer in little-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
int16 ReadInt16LE(TFileCursor &f)
{
return ReadIntLE<int16>(f);
}
// Read signed 16-Bit integer in big-endian format.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
int16 ReadInt16BE(TFileCursor &f)
{
return ReadIntBE<int16>(f);
}
// Read a single 8bit character.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
char ReadChar(TFileCursor &f)
{
char target;
if(Read(f, target))
{
return target;
} else
{
return 0;
}
}
// Read unsigned 8-Bit integer.
// If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
uint8 ReadUint8(TFileCursor &f)
{
uint8 target;
if(Read(f, target))
{
return target;
} else
{
return 0;
}
}
// Read signed 8-Bit integer. If successful, the file cursor is advanced by the size of the integer.
template <typename TFileCursor>
int8 ReadInt8(TFileCursor &f)
{
int8 target;
if(Read(f, target))
{
return target;
} else
{
return 0;
}
}
// Read 32-Bit float in little-endian format.
// If successful, the file cursor is advanced by the size of the float.
template <typename TFileCursor>
float ReadFloatLE(TFileCursor &f)
{
IEEE754binary32LE target;
if(Read(f, target))
{
return target;
} else
{
return 0.0f;
}
}
// Read 32-Bit float in big-endian format.
// If successful, the file cursor is advanced by the size of the float.
template <typename TFileCursor>
float ReadFloatBE(TFileCursor &f)
{
IEEE754binary32BE target;
if(Read(f, target))
{
return target;
} else
{
return 0.0f;
}
}
// Read 64-Bit float in little-endian format.
// If successful, the file cursor is advanced by the size of the float.
template <typename TFileCursor>
double ReadDoubleLE(TFileCursor &f)
{
IEEE754binary64LE target;
if(Read(f, target))
{
return target;
} else
{
return 0.0;
}
}
// Read 64-Bit float in big-endian format.
// If successful, the file cursor is advanced by the size of the float.
template <typename TFileCursor>
double ReadDoubleBE(TFileCursor &f)
{
IEEE754binary64BE target;
if(Read(f, target))
{
return target;
} else
{
return 0.0;
}
}
// Read a struct.
// If successful, the file cursor is advanced by the size of the struct. Otherwise, the target is zeroed.
template <typename T, typename TFileCursor>
bool ReadStruct(TFileCursor &f, T &target)
{
static_assert(mpt::is_binary_safe<T>::value);
if(Read(f, target))
{
return true;
} else
{
Clear(target);
return false;
}
}
// Allow to read a struct partially (if there's less memory available than the struct's size, fill it up with zeros).
// The file cursor is advanced by "partialSize" bytes.
template <typename T, typename TFileCursor>
typename TFileCursor::off_t ReadStructPartial(TFileCursor &f, T &target, typename TFileCursor::off_t partialSize = sizeof(T))
{
static_assert(mpt::is_binary_safe<T>::value);
typename TFileCursor::off_t copyBytes = std::min(partialSize, sizeof(T));
if(!f.CanRead(copyBytes))
{
copyBytes = f.BytesLeft();
}
f.GetRaw(mpt::as_raw_memory(target).data(), copyBytes);
std::memset(mpt::as_raw_memory(target).data() + copyBytes, 0, sizeof(target) - copyBytes);
f.Skip(partialSize);
return copyBytes;
}
// Read a string of length srcSize into fixed-length char array destBuffer using a given read mode.
// The file cursor is advanced by "srcSize" bytes.
// Returns true if at least one byte could be read or 0 bytes were requested.
template<mpt::String::ReadWriteMode mode, size_t destSize, typename TFileCursor>
bool ReadString(TFileCursor &f, char (&destBuffer)[destSize], const typename TFileCursor::off_t srcSize)
{
typename TFileCursor::PinnedRawDataView source = f.ReadPinnedRawDataView(srcSize); // Make sure the string is cached properly.
typename TFileCursor::off_t realSrcSize = source.size(); // In case fewer bytes are available
mpt::String::WriteAutoBuf(destBuffer) = mpt::String::ReadBuf(mode, mpt::byte_cast<const char*>(source.data()), realSrcSize);
return (realSrcSize > 0 || srcSize == 0);
}
// Read a string of length srcSize into a std::string dest using a given read mode.
// The file cursor is advanced by "srcSize" bytes.
// Returns true if at least one character could be read or 0 characters were requested.
template<mpt::String::ReadWriteMode mode, typename TFileCursor>
bool ReadString(TFileCursor &f, std::string &dest, const typename TFileCursor::off_t srcSize)
{
dest.clear();
typename TFileCursor::PinnedRawDataView source = f.ReadPinnedRawDataView(srcSize); // Make sure the string is cached properly.
typename TFileCursor::off_t realSrcSize = source.size(); // In case fewer bytes are available
dest = mpt::String::ReadBuf(mode, mpt::byte_cast<const char*>(source.data()), realSrcSize);
return (realSrcSize > 0 || srcSize == 0);
}
// Read a string of length srcSize into a mpt::charbuf dest using a given read mode.
// The file cursor is advanced by "srcSize" bytes.
// Returns true if at least one character could be read or 0 characters were requested.
template<mpt::String::ReadWriteMode mode, std::size_t len, typename TFileCursor>
bool ReadString(TFileCursor &f, mpt::charbuf<len> &dest, const typename TFileCursor::off_t srcSize)
{
typename TFileCursor::PinnedRawDataView source = f.ReadPinnedRawDataView(srcSize); // Make sure the string is cached properly.
typename TFileCursor::off_t realSrcSize = source.size(); // In case fewer bytes are available
dest = mpt::String::ReadBuf(mode, mpt::byte_cast<const char*>(source.data()), realSrcSize);
return (realSrcSize > 0 || srcSize == 0);
}
// Read a charset encoded string of length srcSize into a mpt::ustring dest using a given read mode.
// The file cursor is advanced by "srcSize" bytes.
// Returns true if at least one character could be read or 0 characters were requested.
template<mpt::String::ReadWriteMode mode, typename TFileCursor>
bool ReadString(TFileCursor &f, mpt::ustring &dest, mpt::Charset charset, const typename TFileCursor::off_t srcSize)
{
dest.clear();
typename TFileCursor::PinnedRawDataView source = f.ReadPinnedRawDataView(srcSize); // Make sure the string is cached properly.
typename TFileCursor::off_t realSrcSize = source.size(); // In case fewer bytes are available
dest = mpt::ToUnicode(charset, mpt::String::ReadBuf(mode, mpt::byte_cast<const char*>(source.data()), realSrcSize));
return (realSrcSize > 0 || srcSize == 0);
}
// Read a string with a preprended length field of type Tsize (must be a packed<*,*> type) into a std::string dest using a given read mode.
// The file cursor is advanced by the string length.
// Returns true if the size field could be read and at least one character could be read or 0 characters were requested.
template<typename Tsize, mpt::String::ReadWriteMode mode, size_t destSize, typename TFileCursor>
bool ReadSizedString(TFileCursor &f, char (&destBuffer)[destSize], const typename TFileCursor::off_t maxLength = std::numeric_limits<typename TFileCursor::off_t>::max())
{
packed<typename Tsize::base_type, typename Tsize::endian_type> srcSize; // Enforce usage of a packed type by ensuring that the passed type has the required typedefs
if(!Read(f, srcSize))
return false;
return ReadString<mode>(f, destBuffer, std::min(static_cast<typename TFileCursor::off_t>(srcSize), maxLength));
}
// Read a string with a preprended length field of type Tsize (must be a packed<*,*> type) into a std::string dest using a given read mode.
// The file cursor is advanced by the string length.
// Returns true if the size field could be read and at least one character could be read or 0 characters were requested.
template<typename Tsize, mpt::String::ReadWriteMode mode, typename TFileCursor>
bool ReadSizedString(TFileCursor &f, std::string &dest, const typename TFileCursor::off_t maxLength = std::numeric_limits<typename TFileCursor::off_t>::max())
{
packed<typename Tsize::base_type, typename Tsize::endian_type> srcSize; // Enforce usage of a packed type by ensuring that the passed type has the required typedefs
if(!Read(f, srcSize))
return false;
return ReadString<mode>(f, dest, std::min(static_cast<typename TFileCursor::off_t>(srcSize), maxLength));
}
// Read a string with a preprended length field of type Tsize (must be a packed<*,*> type) into a mpt::charbuf dest using a given read mode.
// The file cursor is advanced by the string length.
// Returns true if the size field could be read and at least one character could be read or 0 characters were requested.
template<typename Tsize, mpt::String::ReadWriteMode mode, std::size_t len, typename TFileCursor>
bool ReadSizedString(TFileCursor &f, mpt::charbuf<len> &dest, const typename TFileCursor::off_t maxLength = std::numeric_limits<typename TFileCursor::off_t>::max())
{
packed<typename Tsize::base_type, typename Tsize::endian_type> srcSize; // Enforce usage of a packed type by ensuring that the passed type has the required typedefs
if(!Read(f, srcSize))
return false;
return ReadString<mode>(f, dest, std::min(static_cast<typename TFileCursor::off_t>(srcSize), maxLength));
}
// Read a null-terminated string into a std::string
template <typename TFileCursor>
bool ReadNullString(TFileCursor &f, std::string &dest, const typename TFileCursor::off_t maxLength = std::numeric_limits<typename TFileCursor::off_t>::max())
{
dest.clear();
if(!f.CanRead(1))
return false;
try
{
char buffer[64];
typename TFileCursor::off_t avail = 0;
while((avail = std::min(f.GetRaw(buffer, std::size(buffer)), maxLength - dest.length())) != 0)
{
auto end = std::find(buffer, buffer + avail, '\0');
dest.insert(dest.end(), buffer, end);
f.Skip(end - buffer);
if(end < buffer + avail)
{
// Found null char
f.Skip(1);
break;
}
}
} MPT_EXCEPTION_CATCH_OUT_OF_MEMORY(e)
{
MPT_EXCEPTION_DELETE_OUT_OF_MEMORY(e);
}
return dest.length() != 0;
}
// Read a string up to the next line terminator into a std::string
template <typename TFileCursor>
bool ReadLine(TFileCursor &f, std::string &dest, const typename TFileCursor::off_t maxLength = std::numeric_limits<typename TFileCursor::off_t>::max())
{
dest.clear();
if(!f.CanRead(1))
return false;
try
{
char buffer[64];
char c = '\0';
typename TFileCursor::off_t avail = 0;
while((avail = std::min(f.GetRaw(buffer, std::size(buffer)), maxLength - dest.length())) != 0)
{
auto end = std::find_if(buffer, buffer + avail, mpt::String::Traits<std::string>::IsLineEnding);
dest.insert(dest.end(), buffer, end);
f.Skip(end - buffer);
if(end < buffer + avail)
{
// Found line ending
f.Skip(1);
// Handle CRLF line ending
if(*end == '\r')
{
if(Read(f, c) && c != '\n')
f.SkipBack(1);
}
break;
}
}
} MPT_EXCEPTION_CATCH_OUT_OF_MEMORY(e)
{
MPT_EXCEPTION_DELETE_OUT_OF_MEMORY(e);
}
return true;
}
// Read an array of binary-safe T values.
// If successful, the file cursor is advanced by the size of the array.
// Otherwise, the target is zeroed.
template<typename T, std::size_t destSize, typename TFileCursor>
bool ReadArray(TFileCursor &f, T (&destArray)[destSize])
{
static_assert(mpt::is_binary_safe<T>::value);
if(f.CanRead(sizeof(destArray)))
{
f.ReadRaw(mpt::as_raw_memory(destArray));
return true;
} else
{
Clear(destArray);
return false;
}
}
// Read an array of binary-safe T values.
// If successful, the file cursor is advanced by the size of the array.
// Otherwise, the target is zeroed.
template<typename T, std::size_t destSize, typename TFileCursor>
bool ReadArray(TFileCursor &f, std::array<T, destSize> &destArray)
{
static_assert(mpt::is_binary_safe<T>::value);
if(f.CanRead(sizeof(destArray)))
{
f.ReadRaw(mpt::as_raw_memory(destArray));
return true;
} else
{
destArray.fill(T());
return false;
}
}
// Read destSize elements of binary-safe type T into a vector.
// If successful, the file cursor is advanced by the size of the vector.
// Otherwise, the vector is resized to destSize, but possibly existing contents are not cleared.
template<typename T, typename TFileCursor>
bool ReadVector(TFileCursor &f, std::vector<T> &destVector, size_t destSize)
{
static_assert(mpt::is_binary_safe<T>::value);
destVector.resize(destSize);
if(f.CanRead(sizeof(T) * destSize))
{
f.ReadRaw(mpt::as_raw_memory(destVector));
return true;
} else
{
return false;
}
}
template <typename T, std::size_t destSize, typename TFileCursor>
std::array<T, destSize> ReadArray(TFileCursor &f)
{
std::array<T, destSize> destArray;
ReadArray(f, destArray);
return destArray;
}
// Compare a magic string with the current stream position.
// Returns true if they are identical and advances the file cursor by the the length of the "magic" string.
// Returns false if the string could not be found. The file cursor is not advanced in this case.
template <typename TFileCursor>
bool ReadMagic(TFileCursor &f, const char *const magic, typename TFileCursor::off_t magicLength)
{
std::byte buffer[16] = { std::byte(0) };
typename TFileCursor::off_t bytesRead = 0;
typename TFileCursor::off_t bytesRemain = magicLength;
while(bytesRemain)
{
typename TFileCursor::off_t numBytes = std::min(static_cast<typename TFileCursor::off_t>(sizeof(buffer)), bytesRemain);
if(f.GetRawWithOffset(bytesRead, buffer, numBytes) != numBytes)
return false;
if(memcmp(buffer, magic + bytesRead, numBytes))
return false;
bytesRemain -= numBytes;
bytesRead += numBytes;
}
f.Skip(magicLength);
return true;
}
template<size_t N, typename TFileCursor>
bool ReadMagic(TFileCursor &f, const char (&magic)[N])
{
MPT_ASSERT(magic[N - 1] == '\0');
for(std::size_t i = 0; i < N - 1; ++i)
{
MPT_ASSERT(magic[i] != '\0');
}
return ReadMagic(f, static_cast<const char*>(magic), static_cast<typename TFileCursor::off_t>(N - 1));
}
// Read variable-length unsigned integer (as found in MIDI files).
// If successful, the file cursor is advanced by the size of the integer and true is returned.
// False is returned if not enough bytes were left to finish reading of the integer or if an overflow happened (source doesn't fit into target integer).
// In case of an overflow, the target is also set to the maximum value supported by its data type.
template<typename T, typename TFileCursor>
bool ReadVarInt(TFileCursor &f, T &target)
{
static_assert(std::numeric_limits<T>::is_integer == true
&& std::numeric_limits<T>::is_signed == false,
"Target type is not an unsigned integer");
if(f.NoBytesLeft())
{
target = 0;
return false;
}
std::byte bytes[16]; // More than enough for any valid VarInt
typename TFileCursor::off_t avail = f.GetRaw(bytes, sizeof(bytes));
typename TFileCursor::off_t readPos = 1;
uint8 b = mpt::byte_cast<uint8>(bytes[0]);
target = (b & 0x7F);
size_t writtenBits = static_cast<size_t>(mpt::bit_width(target)); // Bits used in the most significant byte
while(readPos < avail && (b & 0x80) != 0)
{
b = mpt::byte_cast<uint8>(bytes[readPos++]);
target <<= 7;
target |= (b & 0x7F);
writtenBits += 7;
if(readPos == avail)
{
f.Skip(readPos);
avail = f.GetRaw(bytes, sizeof(bytes));
readPos = 0;
}
}
f.Skip(readPos);
if(writtenBits > sizeof(target) * 8u)
{
// Overflow
target = Util::MaxValueOfType<T>(target);
return false;
} else if((b & 0x80) != 0)
{
// Reached EOF
return false;
}
return true;
}
} // namespace FileReader
} // namespace mpt
namespace FR = mpt::FileReader;
namespace detail {
template <typename Ttraits>
class FileReader
{
private:
using traits_type = Ttraits;
public:
using off_t = typename traits_type::off_t;
using data_type = typename traits_type::data_type;
using ref_data_type = typename traits_type::ref_data_type;
using shared_data_type = typename traits_type::shared_data_type;
using value_data_type = typename traits_type::value_data_type;
protected:
shared_data_type SharedDataContainer() const { return traits_type::get_shared(m_data); }
ref_data_type DataContainer() const { return traits_type::get_ref(m_data); }
static value_data_type DataInitializer() { return traits_type::make_data(); }
static value_data_type DataInitializer(mpt::const_byte_span data) { return traits_type::make_data(data); }
static value_data_type CreateChunkImpl(shared_data_type data, off_t position, off_t size) { return traits_type::make_chunk(data, position, size); }
private:
data_type m_data;
off_t streamPos; // Cursor location in the file
const mpt::PathString *fileName; // Filename that corresponds to this FileReader. It is only set if this FileReader represents the whole contents of fileName. May be nullptr. Lifetime is managed outside of FileReader.
public:
// Initialize invalid file reader object.
FileReader() : m_data(DataInitializer()), streamPos(0), fileName(nullptr) { }
// Initialize file reader object with pointer to data and data length.
template <typename Tbyte> FileReader(mpt::span<Tbyte> bytedata, const mpt::PathString *filename = nullptr) : m_data(DataInitializer(mpt::byte_cast<mpt::const_byte_span>(bytedata))), streamPos(0), fileName(filename) { }
// Initialize file reader object based on an existing file reader object window.
explicit FileReader(value_data_type other, const mpt::PathString *filename = nullptr) : m_data(other), streamPos(0), fileName(filename) { }
public:
mpt::PathString GetFileName() const
{
if(!fileName)
{
return mpt::PathString();
}
return *fileName;
}
// Returns true if the object points to a valid (non-empty) stream.
operator bool() const
{
return IsValid();
}
// Returns true if the object points to a valid (non-empty) stream.
bool IsValid() const
{
return DataContainer().IsValid();
}
// Reset cursor to first byte in file.
void Rewind()
{
streamPos = 0;
}
// Seek to a position in the mapped file.
// Returns false if position is invalid.
bool Seek(off_t position)
{
if(position <= streamPos)
{
streamPos = position;
return true;
}
if(position <= DataContainer().GetLength())
{
streamPos = position;
return true;
} else
{
return false;
}
}
// Increases position by skipBytes.
// Returns true if skipBytes could be skipped or false if the file end was reached earlier.
bool Skip(off_t skipBytes)
{
if(CanRead(skipBytes))
{
streamPos += skipBytes;
return true;
} else
{
streamPos = DataContainer().GetLength();
return false;
}
}
// Decreases position by skipBytes.
// Returns true if skipBytes could be skipped or false if the file start was reached earlier.
bool SkipBack(off_t skipBytes)
{
if(streamPos >= skipBytes)
{
streamPos -= skipBytes;
return true;
} else
{
streamPos = 0;
return false;
}
}
// Returns cursor position in the mapped file.
off_t GetPosition() const
{
return streamPos;
}
// Return true IFF seeking and GetLength() is fast.
// In particular, it returns false for unseekable stream where GetLength()
// requires pre-caching.
bool HasFastGetLength() const
{
return DataContainer().HasFastGetLength();
}
// Returns size of the mapped file in bytes.
FILEREADER_DEPRECATED off_t GetLength() const
{
// deprecated because in case of an unseekable std::istream, this triggers caching of the whole file
return DataContainer().GetLength();
}
// Return byte count between cursor position and end of file, i.e. how many bytes can still be read.
FILEREADER_DEPRECATED off_t BytesLeft() const
{
// deprecated because in case of an unseekable std::istream, this triggers caching of the whole file
return DataContainer().GetLength() - streamPos;
}
bool EndOfFile() const
{
return !CanRead(1);
}
bool NoBytesLeft() const
{
return !CanRead(1);
}
// Check if "amount" bytes can be read from the current position in the stream.
bool CanRead(off_t amount) const
{
return DataContainer().CanRead(streamPos, amount);
}
// Check if file size is at least size, without potentially caching the whole file to query the exact file length.
bool LengthIsAtLeast(off_t size) const
{
return DataContainer().CanRead(0, size);
}
// Check if file size is exactly size, without potentially caching the whole file if it is larger.
bool LengthIs(off_t size) const
{
return DataContainer().CanRead(0, size) && !DataContainer().CanRead(size, 1);
}
protected:
FileReader CreateChunk(off_t position, off_t length) const
{
off_t readableLength = DataContainer().GetReadableLength(position, length);
if(readableLength == 0)
{
return FileReader();
}
return FileReader(CreateChunkImpl(SharedDataContainer(), position, std::min(length, DataContainer().GetLength() - position)));
}
public:
// Create a new FileReader object for parsing a sub chunk at a given position with a given length.
// The file cursor is not modified.
FileReader GetChunkAt(off_t position, off_t length) const
{
return CreateChunk(position, length);
}
// Create a new FileReader object for parsing a sub chunk at the current position with a given length.
// The file cursor is not advanced.
FileReader GetChunk(off_t length)
{
return CreateChunk(streamPos, length);
}
// Create a new FileReader object for parsing a sub chunk at the current position with a given length.
// The file cursor is advanced by "length" bytes.
FileReader ReadChunk(off_t length)
{
off_t position = streamPos;
Skip(length);
return CreateChunk(position, length);
}
class PinnedRawDataView
{
private:
std::size_t size_;
const std::byte *pinnedData;
std::vector<std::byte> cache;
private:
void Init(const FileReader &file, std::size_t size)
{
size_ = 0;
pinnedData = nullptr;
if(!file.CanRead(size))
{
size = file.BytesLeft();
}
size_ = size;
if(file.DataContainer().HasPinnedView())
{
pinnedData = file.DataContainer().GetRawData() + file.GetPosition();
} else
{
cache.resize(size_);
if(!cache.empty())
{
// cppcheck false-positive
// cppcheck-suppress containerOutOfBounds
file.GetRaw(&(cache[0]), size);
}
}
}
public:
PinnedRawDataView()
: size_(0)
, pinnedData(nullptr)
{
}
PinnedRawDataView(const FileReader &file)
{
Init(file, file.BytesLeft());
}
PinnedRawDataView(const FileReader &file, std::size_t size)
{
Init(file, size);
}
PinnedRawDataView(FileReader &file, bool advance)
{
Init(file, file.BytesLeft());
if(advance)
{
file.Skip(size_);
}
}
PinnedRawDataView(FileReader &file, std::size_t size, bool advance)
{
Init(file, size);
if(advance)
{
file.Skip(size_);
}
}
public:
mpt::const_byte_span GetSpan() const
{
if(pinnedData)
{
return mpt::as_span(pinnedData, size_);
} else if(!cache.empty())
{
return mpt::as_span(cache);
} else
{
return mpt::const_byte_span();
}
}
mpt::const_byte_span span() const { return GetSpan(); }
void invalidate() { size_ = 0; pinnedData = nullptr; cache = std::vector<std::byte>(); }
const std::byte *data() const { return span().data(); }
std::size_t size() const { return size_; }
mpt::const_byte_span::pointer begin() const { return span().data(); }
mpt::const_byte_span::pointer end() const { return span().data() + span().size(); }
mpt::const_byte_span::const_pointer cbegin() const { return span().data(); }
mpt::const_byte_span::const_pointer cend() const { return span().data() + span().size(); }
};
// Returns a pinned view into the remaining raw data from cursor position.
PinnedRawDataView GetPinnedRawDataView() const
{
return PinnedRawDataView(*this);
}
// Returns a pinned view into the remeining raw data from cursor position, clamped at size.
PinnedRawDataView GetPinnedRawDataView(std::size_t size) const
{
return PinnedRawDataView(*this, size);
}
// Returns a pinned view into the remeining raw data from cursor position.
// File cursor is advaned by the size of the returned pinned view.
PinnedRawDataView ReadPinnedRawDataView()
{
return PinnedRawDataView(*this, true);
}
// Returns a pinned view into the remeining raw data from cursor position, clamped at size.
// File cursor is advaned by the size of the returned pinned view.
PinnedRawDataView ReadPinnedRawDataView(std::size_t size)
{
return PinnedRawDataView(*this, size, true);
}
// Returns raw stream data at cursor position.
// Should only be used if absolutely necessary, for example for sample reading, or when used with a small chunk of the file retrieved by ReadChunk().
// Use GetPinnedRawDataView(size) whenever possible.
FILEREADER_DEPRECATED const std::byte *GetRawData() const
{
// deprecated because in case of an unseekable std::istream, this triggers caching of the whole file
return DataContainer().GetRawData() + streamPos;
}
template <typename T>
FILEREADER_DEPRECATED const T *GetRawData() const
{
// deprecated because in case of an unseekable std::istream, this triggers caching of the whole file
return mpt::byte_cast<const T*>(DataContainer().GetRawData() + streamPos);
}
template <typename T>
std::size_t GetRawWithOffset(std::size_t offset, T *dst, std::size_t count) const
{
return static_cast<std::size_t>(DataContainer().Read(mpt::byte_cast<std::byte*>(dst), streamPos + offset, count));
}
std::size_t GetRawWithOffset(std::size_t offset, mpt::byte_span dst) const
{
return static_cast<std::size_t>(DataContainer().Read(streamPos + offset, dst));
}
template <typename T>
std::size_t GetRaw(T *dst, std::size_t count) const
{
return static_cast<std::size_t>(DataContainer().Read(mpt::byte_cast<std::byte*>(dst), streamPos, count));
}
std::size_t GetRaw(mpt::byte_span dst) const
{
return static_cast<std::size_t>(DataContainer().Read(streamPos, dst));
}
template <typename T>
std::size_t ReadRaw(T *dst, std::size_t count)
{
std::size_t result = static_cast<std::size_t>(DataContainer().Read(mpt::byte_cast<std::byte*>(dst), streamPos, count));
streamPos += result;
return result;
}
std::size_t ReadRaw(mpt::byte_span dst)
{
std::size_t result = static_cast<std::size_t>(DataContainer().Read(streamPos, dst));
streamPos += result;
return result;
}
std::vector<std::byte> GetRawDataAsByteVector() const
{
PinnedRawDataView view = GetPinnedRawDataView();
return mpt::make_vector(view.span());
}
std::vector<std::byte> ReadRawDataAsByteVector()
{
PinnedRawDataView view = ReadPinnedRawDataView();
return mpt::make_vector(view.span());
}
std::vector<std::byte> GetRawDataAsByteVector(std::size_t size) const
{
PinnedRawDataView view = GetPinnedRawDataView(size);
return mpt::make_vector(view.span());
}
std::vector<std::byte> ReadRawDataAsByteVector(std::size_t size)
{
PinnedRawDataView view = ReadPinnedRawDataView(size);
return mpt::make_vector(view.span());
}
std::string GetRawDataAsString() const
{
PinnedRawDataView view = GetPinnedRawDataView();
mpt::span<const char> data = mpt::byte_cast<mpt::span<const char>>(view.span());
return std::string(data.begin(), data.end());
}
std::string ReadRawDataAsString()
{
PinnedRawDataView view = ReadPinnedRawDataView();
mpt::span<const char> data = mpt::byte_cast<mpt::span<const char>>(view.span());
return std::string(data.begin(), data.end());
}
std::string GetRawDataAsString(std::size_t size) const
{
PinnedRawDataView view = GetPinnedRawDataView(size);
mpt::span<const char> data = mpt::byte_cast<mpt::span<const char>>(view.span());
return std::string(data.begin(), data.end());
}
std::string ReadRawDataAsString(std::size_t size)
{
PinnedRawDataView view = ReadPinnedRawDataView(size);
mpt::span<const char> data = mpt::byte_cast<mpt::span<const char>>(view.span());
return std::string(data.begin(), data.end());
}
template <typename T>
bool Read(T &target)
{
return mpt::FileReader::Read(*this, target);
}
template <typename T>
T ReadIntLE()
{
return mpt::FileReader::ReadIntLE<T>(*this);
}
template <typename T>
T ReadIntBE()
{
return mpt::FileReader::ReadIntLE<T>(*this);
}
template <typename T>
T ReadTruncatedIntLE(off_t size)
{
return mpt::FileReader::ReadTruncatedIntLE<T>(*this, size);
}
template <typename T>
T ReadSizedIntLE(off_t size)
{
return mpt::FileReader::ReadSizedIntLE<T>(*this, size);
}
uint32 ReadUint32LE()
{
return mpt::FileReader::ReadUint32LE(*this);
}
uint32 ReadUint32BE()
{
return mpt::FileReader::ReadUint32BE(*this);
}
int32 ReadInt32LE()
{
return mpt::FileReader::ReadInt32LE(*this);
}
int32 ReadInt32BE()
{
return mpt::FileReader::ReadInt32BE(*this);
}
uint16 ReadUint16LE()
{
return mpt::FileReader::ReadUint16LE(*this);
}
uint16 ReadUint16BE()
{
return mpt::FileReader::ReadUint16BE(*this);
}
int16 ReadInt16LE()
{
return mpt::FileReader::ReadInt16LE(*this);
}
int16 ReadInt16BE()
{
return mpt::FileReader::ReadInt16BE(*this);
}
char ReadChar()
{
return mpt::FileReader::ReadChar(*this);
}
uint8 ReadUint8()
{
return mpt::FileReader::ReadUint8(*this);
}
int8 ReadInt8()
{
return mpt::FileReader::ReadInt8(*this);
}
float ReadFloatLE()
{
return mpt::FileReader::ReadFloatLE(*this);
}
float ReadFloatBE()
{
return mpt::FileReader::ReadFloatBE(*this);
}
double ReadDoubleLE()
{
return mpt::FileReader::ReadDoubleLE(*this);
}
double ReadDoubleBE()
{
return mpt::FileReader::ReadDoubleBE(*this);
}
template <typename T>
bool ReadStruct(T &target)
{
return mpt::FileReader::ReadStruct(*this, target);
}
template <typename T>
size_t ReadStructPartial(T &target, size_t partialSize = sizeof(T))
{
return mpt::FileReader::ReadStructPartial(*this, target, partialSize);
}
template<mpt::String::ReadWriteMode mode, size_t destSize>
bool ReadString(char (&destBuffer)[destSize], const off_t srcSize)
{
return mpt::FileReader::ReadString<mode>(*this, destBuffer, srcSize);
}
template<mpt::String::ReadWriteMode mode>
bool ReadString(std::string &dest, const off_t srcSize)
{
return mpt::FileReader::ReadString<mode>(*this, dest, srcSize);
}
template<mpt::String::ReadWriteMode mode, std::size_t len>
bool ReadString(mpt::charbuf<len> &dest, const off_t srcSize)
{
return mpt::FileReader::ReadString<mode>(*this, dest, srcSize);
}
template<mpt::String::ReadWriteMode mode>
bool ReadString(mpt::ustring &dest, mpt::Charset charset, const off_t srcSize)
{
return mpt::FileReader::ReadString<mode>(*this, dest, charset, srcSize);
}
template<typename Tsize, mpt::String::ReadWriteMode mode, size_t destSize>
bool ReadSizedString(char (&destBuffer)[destSize], const off_t maxLength = std::numeric_limits<off_t>::max())
{
return mpt::FileReader::ReadSizedString<Tsize, mode>(*this, destBuffer, maxLength);
}
template<typename Tsize, mpt::String::ReadWriteMode mode>
bool ReadSizedString(std::string &dest, const off_t maxLength = std::numeric_limits<off_t>::max())
{
return mpt::FileReader::ReadSizedString<Tsize, mode>(*this, dest, maxLength);
}
template<typename Tsize, mpt::String::ReadWriteMode mode, std::size_t len>
bool ReadSizedString(mpt::charbuf<len> &dest, const off_t maxLength = std::numeric_limits<off_t>::max())
{
return mpt::FileReader::ReadSizedString<Tsize, mode, len>(*this, dest, maxLength);
}
bool ReadNullString(std::string &dest, const off_t maxLength = std::numeric_limits<off_t>::max())
{
return mpt::FileReader::ReadNullString(*this, dest, maxLength);
}
bool ReadLine(std::string &dest, const off_t maxLength = std::numeric_limits<off_t>::max())
{
return mpt::FileReader::ReadLine(*this, dest, maxLength);
}
template<typename T, std::size_t destSize>
bool ReadArray(T (&destArray)[destSize])
{
return mpt::FileReader::ReadArray(*this, destArray);
}
template<typename T, std::size_t destSize>
bool ReadArray(std::array<T, destSize> &destArray)
{
return mpt::FileReader::ReadArray(*this, destArray);
}
template <typename T, std::size_t destSize>
std::array<T, destSize> ReadArray()
{
return mpt::FileReader::ReadArray<T, destSize>(*this);
}
template<typename T>
bool ReadVector(std::vector<T> &destVector, size_t destSize)
{
return mpt::FileReader::ReadVector(*this, destVector, destSize);
}
template<size_t N>
bool ReadMagic(const char (&magic)[N])
{
return mpt::FileReader::ReadMagic(*this, magic);
}
bool ReadMagic(const char *const magic, off_t magicLength)
{
return mpt::FileReader::ReadMagic(*this, magic, magicLength);
}
template<typename T>
bool ReadVarInt(T &target)
{
return mpt::FileReader::ReadVarInt(*this, target);
}
};
} // namespace detail
using FileReader = detail::FileReader<FileReaderTraitsDefault>;
using MemoryFileReader = detail::FileReader<FileReaderTraitsMemory>;
// Initialize file reader object with pointer to data and data length.
template <typename Tbyte> inline FileReader make_FileReader(mpt::span<Tbyte> bytedata, const mpt::PathString *filename = nullptr)
{
return FileReader(mpt::byte_cast<mpt::const_byte_span>(bytedata), filename);
}
#if defined(MPT_FILEREADER_CALLBACK_STREAM)
// Initialize file reader object with a CallbackStream.
inline FileReader make_FileReader(CallbackStream s, const mpt::PathString *filename = nullptr)
{
return FileReader(
FileDataContainerCallbackStreamSeekable::IsSeekable(s) ?
std::static_pointer_cast<IFileDataContainer>(std::make_shared<FileDataContainerCallbackStreamSeekable>(s))
:
std::static_pointer_cast<IFileDataContainer>(std::make_shared<FileDataContainerCallbackStream>(s))
, filename
);
}
#endif // MPT_FILEREADER_CALLBACK_STREAM
// Initialize file reader object with a std::istream.
inline FileReader make_FileReader(std::istream *s, const mpt::PathString *filename = nullptr)
{
return FileReader(
FileDataContainerStdStreamSeekable::IsSeekable(s) ?
std::static_pointer_cast<IFileDataContainer>(std::make_shared<FileDataContainerStdStreamSeekable>(s))
:
std::static_pointer_cast<IFileDataContainer>(std::make_shared<FileDataContainerStdStream>(s))
, filename
);
}
#if defined(MPT_ENABLE_FILEIO)
// templated in order to reduce header inter-dependencies
template <typename TInputFile>
FileReader GetFileReader(TInputFile &file)
{
if(!file.IsValid())
{
return FileReader();
}
if(file.IsCached())
{
return make_FileReader(file.GetCache(), &file.GetFilenameRef());
} else
{
return make_FileReader(file.GetStream(), &file.GetFilenameRef());
}
}
#endif // MPT_ENABLE_FILEIO
#if defined(MPT_ENABLE_TEMPFILE) && MPT_OS_WINDOWS
class OnDiskFileWrapper
{
private:
mpt::PathString m_Filename;
bool m_IsTempFile;
public:
OnDiskFileWrapper(FileReader &file, const mpt::PathString &fileNameExtension = P_("tmp"));
~OnDiskFileWrapper();
public:
bool IsValid() const;
mpt::PathString GetFilename() const;
}; // class OnDiskFileWrapper
#endif // MPT_ENABLE_TEMPFILE && MPT_OS_WINDOWS
OPENMPT_NAMESPACE_END