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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef COMMON_STREAM_H
#define COMMON_STREAM_H
#include "common/endian.h"
#include "common/ptr.h"
#include "common/scummsys.h"
#include "common/str.h"
#include "common/data-io.h"
namespace Common {
/**
* @defgroup common_stream Streams
* @ingroup common
*
* @brief API for managing readable and writable data streams.
*
* @{
*/
class ReadStream;
class SeekableReadStream;
/**
* Virtual base class for both ReadStream and WriteStream.
*/
class Stream {
public:
virtual ~Stream() {}
/**
* Return true if an I/O failure occurred.
*
* This flag is never cleared automatically. In order to clear it,
* the client code must call clearErr() explicitly.
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C ferror().
*/
virtual bool err() const { return false; }
/**
* Reset the I/O error status as returned by err().
*
* For a ReadStream, also reset the end-of-stream status returned by eos().
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C clearerr().
*/
virtual void clearErr() {}
};
/**
* Generic interface for a writable data stream.
*/
class WriteStream : virtual public Stream {
public:
/**
* Write data into the stream. Subclasses must implement this
* method. All other write methods are implemented using it.
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C fwrite().
*
* @param dataPtr Pointer to the data to be written.
* @param dataSize Number of bytes to be written.
*
* @return The number of bytes that were actually written.
*/
virtual uint32 write(const void *dataPtr, uint32 dataSize) = 0;
/**
* Commit any buffered data to the underlying channel or
* storage medium. Unbuffered streams can use the default
* implementation.
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C fflush().
*
* @return True on success, false in case of a failure.
*/
virtual bool flush() { return true; }
/**
* Finalize and close this stream.
*
* Call this method right before this stream instance is deleted.
* The goal is to enable the client code to detect
* and handle I/O errors that might occur when closing
* (and flushing, if buffered) the stream.
*
* After this method has been called, no further writes can be
* performed on the stream. Calling err() is allowed.
*
* By default, this just flushes the stream.
*/
virtual void finalize() {
flush();
}
/**
* Obtain the current value of the stream position indicator.
*
* @return The current position indicator, or -1 if an error occurred.
*/
virtual int64 pos() const = 0;
/**
* @name Functions for writing data
*
* The following methods all have default implementations.
* Subclasses need not (and should not) overload them.
* @{
*/
/**
* Write the given byte to the current position in the stream.
*/
void writeByte(byte value) {
write(&value, 1);
}
/**
* Write the given signed byte to the current position in the stream.
*/
void writeSByte(int8 value) {
write(&value, 1);
}
/**
* Write an unsigned 16-bit word stored in little endian order into the stream.
*/
void writeUint16LE(uint16 value) {
value = TO_LE_16(value);
write(&value, 2);
}
/**
* Write an unsigned 32-bit word stored in little endian order into the stream.
*/
void writeUint32LE(uint32 value) {
value = TO_LE_32(value);
write(&value, 4);
}
/**
* Write an unsigned 64-bit word stored in little endian order into the stream.
*/
void writeUint64LE(uint64 value) {
value = TO_LE_64(value);
write(&value, 8);
}
/**
* Write an unsigned 16-bit word stored in big endian order into the stream.
*/
void writeUint16BE(uint16 value) {
value = TO_BE_16(value);
write(&value, 2);
}
/**
* Write an unsigned 32-bit word stored in big endian order into the stream.
*/
void writeUint32BE(uint32 value) {
value = TO_BE_32(value);
write(&value, 4);
}
/**
* Write an unsigned 64-bit word stored in big endian order into the stream.
*/
void writeUint64BE(uint64 value) {
value = TO_BE_64(value);
write(&value, 8);
}
/**
* Write a signed 16-bit word stored in little endian order into the stream.
*/
FORCEINLINE void writeSint16LE(int16 value) {
writeUint16LE((uint16)value);
}
/**
* Write a signed 32-bit word stored in little endian order into the stream.
*/
FORCEINLINE void writeSint32LE(int32 value) {
writeUint32LE((uint32)value);
}
/**
* Write a signed 64-bit word stored in little endian order into the stream.
*/
FORCEINLINE void writeSint64LE(int64 value) {
writeUint64LE((uint64)value);
}
/**
* Write a signed 16-bit word stored in big endian order into the stream.
*/
FORCEINLINE void writeSint16BE(int16 value) {
writeUint16BE((uint16)value);
}
/**
* Write a signed 32-bit word stored in big endian order into the stream.
*/
FORCEINLINE void writeSint32BE(int32 value) {
writeUint32BE((uint32)value);
}
/**
* Write a signed 64-bit word stored in big endian order into the stream.
*/
FORCEINLINE void writeSint64BE(int64 value) {
writeUint64BE((uint64)value);
}
/**
* Write a 32-bit floating point value
* stored in little endian (LSB first) order into the stream.
*/
FORCEINLINE void writeFloatLE(float value) {
uint32 n;
memcpy(&n, &value, 4);
writeUint32LE(n);
}
/**
* Write a 32-bit floating point value
* stored in big endian order into the stream.
*/
FORCEINLINE void writeFloatBE(float value) {
uint32 n;
memcpy(&n, &value, 4);
writeUint32BE(n);
}
/**
* Write a 64-bit floating point value (with decimals)
* stored in little endian (LSB first) order into the stream.
*/
FORCEINLINE void writeDoubleLE(double value) {
uint64 n;
memcpy(&n, &value, 8);
writeUint64LE(n);
}
/**
* Write the given 64-bit floating point value (with decimals)
* stored in big endian order into the stream.
*/
FORCEINLINE void writeDoubleBE(double value) {
uint64 n;
memcpy(&n, &value, 8);
writeUint64BE(n);
}
/**
* Write multiple values to the stream using a specified data format,
* return true on success and false on failure.
*/
template<class TDataFormat, class... T>
bool writeMultiple(const TDataFormat &dataFormat, const T &...values) {
const TDataFormat dataFormatCopy = dataFormat; // Copy to help compiler alias analysis, parameter is const ref to ensure TDataFormat is a concrete type
byte buffer[DataMultipleIO<TDataFormat, T...>::kMaxSize];
const uint actualSize = DataMultipleIO<TDataFormat, T...>::computeSize(dataFormatCopy);
DataMultipleIO<TDataFormat, T...>::encode(dataFormatCopy, buffer, values...);
if (this->write(buffer, actualSize) != actualSize)
return false;
return true;
}
/**
* Write multiple values to the stream using a specified endianness,
* return true on success and false on failure.
*/
template<class... T>
inline bool writeMultipleEndian(bool isLittle, const T &...values) {
return this->writeMultiple<EndianStorageFormat, T...>(isLittle ? EndianStorageFormat::Little : EndianStorageFormat::Big, values...);
}
/**
* Write multiple values to the stream in little endian format,
* return true on success and false on failure.
*/
template<class... T>
inline bool writeMultipleLE(const T &...values) {
return this->writeMultiple<EndianStorageFormat, T...>(EndianStorageFormat::Little, values...);
}
/**
* Write multiple values to the stream in big endian format,
* return true on success and false on failure.
*/
template<class... T>
inline bool writeMultipleBE(const T &...values) {
return this->writeMultiple<EndianStorageFormat, T...>(EndianStorageFormat::Big, values...);
}
/**
* Write at most @p dataSize of data from another stream into this one,
* starting from the current stream position.
*
* @return The number of bytes written into the stream.
*/
uint32 writeStream(ReadStream *stream, uint32 dataSize);
/**
* Write data from another stream into this one,
* starting from its current position to the end of the stream.
*
* @return The number of bytes written into the stream.
*/
uint32 writeStream(ReadStream *stream);
/**
* Write the given string to the stream.
* This writes str.size() characters, but no terminating zero byte.
*/
void writeString(const String &str);
/** @} */
};
/**
* Derived abstract base class for write streams that are seekable.
*/
class SeekableWriteStream : public WriteStream {
public:
/**
* Set the stream position indicator for the stream.
*
* The new position, measured in bytes, is obtained by adding offset bytes
* to the position specified by whence. If whence is set to SEEK_SET, SEEK_CUR,
* or SEEK_END, the offset is relative to the start of the file, the current
* position indicator, or end-of-stream, respectively. A successful call
* to the seek() method clears the end-of-stream indicator for the stream.
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C fseek().
*
* @param offset The relative offset in bytes.
* @param whence The seek reference: SEEK_SET, SEEK_CUR, or SEEK_END.
*
* @return True on success, false in case of a failure.
*/
virtual bool seek(int64 offset, int whence = SEEK_SET) = 0;
/**
* Obtain the current size of the stream, measured in bytes.
*
* If this value is unknown or cannot be computed, -1 is returned.
*
* @return The size of the stream, or -1 if an error occurred.
*/
virtual int64 size() const = 0;
};
/**
* Generic interface for a readable data stream.
*/
class ReadStream : virtual public Stream {
public:
ReadStream() {}
/**
* Return true if a read failed because the stream end has been reached.
*
* This flag is cleared by clearErr().
* For a SeekableReadStream, the flag is also cleared by a successful seek.
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C feof(). In particular, in a stream
* with N bytes, reading exactly N bytes from the start should *not*
* set eos; only reading *beyond* the available data should set it.
*/
virtual bool eos() const = 0;
/**
* Read data from the stream.
*
* Subclasses must implement this method.
* All other read methods are implemented using it.
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C fread(), in particular where
* it concerns setting error and end of file/stream flags.
*
* @param dataPtr Pointer to a buffer into which the data is read.
* @param dataSize Number of bytes to be read.
*
* @return The number of bytes that were actually read.
*/
virtual uint32 read(void *dataPtr, uint32 dataSize) = 0;
/**
* @name Functions for reading data
*
* The following methods all have default implementations.
* Subclasses in general should not overload them.
* @{
*/
/**
* Read an unsigned byte from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
byte readByte() {
byte b = 0; // FIXME: remove initialisation
read(&b, 1);
return b;
}
/**
* Read a signed byte from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE int8 readSByte() {
return (int8)readByte();
}
/**
* Read an unsigned 16-bit word stored in little endian (LSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
uint16 readUint16LE() {
uint16 val;
read(&val, 2);
return FROM_LE_16(val);
}
/**
* Read an unsigned 32-bit word stored in little endian (LSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
uint32 readUint32LE() {
uint32 val;
read(&val, 4);
return FROM_LE_32(val);
}
/**
* Read an unsigned 64-bit word stored in little endian (LSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
uint64 readUint64LE() {
uint64 val;
read(&val, 8);
return FROM_LE_64(val);
}
/**
* Read an unsigned 16-bit word stored in big endian (MSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
uint16 readUint16BE() {
uint16 val;
read(&val, 2);
return FROM_BE_16(val);
}
/**
* Read an unsigned 32-bit word stored in big endian (MSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
uint32 readUint32BE() {
uint32 val;
read(&val, 4);
return FROM_BE_32(val);
}
/**
* Read an unsigned 64-bit word stored in big endian (MSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
uint64 readUint64BE() {
uint64 val;
read(&val, 8);
return FROM_BE_64(val);
}
/**
* Read a signed 16-bit word stored in little endian (LSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE int16 readSint16LE() {
return (int16)readUint16LE();
}
/**
* Read a signed 32-bit word stored in little endian (LSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE int32 readSint32LE() {
return (int32)readUint32LE();
}
/**
* Read a signed 64-bit word stored in little endian (LSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE int64 readSint64LE() {
return (int64)readUint64LE();
}
/**
* Read a signed 16-bit word stored in big endian (MSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE int16 readSint16BE() {
return (int16)readUint16BE();
}
/**
* Read a signed 32-bit word stored in big endian (MSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE int32 readSint32BE() {
return (int32)readUint32BE();
}
/**
* Read a signed 64-bit word stored in big endian (MSB first) order
* from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE int64 readSint64BE() {
return (int64)readUint64BE();
}
/**
* Read a 32-bit floating point value stored in little endian (LSB first)
* order from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE float readFloatLE() {
uint8 val[4];
read(val, 4);
return READ_LE_FLOAT32(val);
}
/**
* Read a 32-bit floating point value stored in big endian
* order from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE float readFloatBE() {
uint8 val[4];
read(val, 4);
return READ_BE_FLOAT32(val);
}
/**
* Read a 64-bit floating point value stored in little endian (LSB first)
* order from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE double readDoubleLE() {
uint8 val[8];
read(val, 8);
return READ_LE_FLOAT64(val);
}
/**
* Read a 64-bit floating point value stored in big endian
* order from the stream and return it.
*
* Performs no error checking. The return value is undefined
* if a read error occurred (for which the client code can check by
* calling err() and eos() ).
*/
FORCEINLINE double readDoubleBE() {
uint8 val[8];
read(val, 8);
return READ_BE_FLOAT64(val);
}
/**
* Read multiple values from the stream using a specified data format,
* return true on success and false on failure.
*/
template<class TDataFormat, class... T>
bool readMultiple(const TDataFormat &dataFormat, T &...values) {
const TDataFormat dataFormatCopy = dataFormat; // Copy to help compiler alias analysis, parameter is const ref to ensure TDataFormat is a concrete type
byte buffer[DataMultipleIO<TDataFormat, T...>::kMaxSize];
const uint actualSize = DataMultipleIO<TDataFormat, T...>::computeSize(dataFormatCopy);
if (read(buffer, actualSize) != actualSize)
return false;
DataMultipleIO<TDataFormat, T...>::decode(dataFormatCopy, buffer, values...);
return true;
}
/**
* Read multiple values from the stream using a specified endianness,
* return true on success and false on failure.
*/
template<class... T>
inline bool readMultipleEndian(bool isLittle, T &...values) {
return this->readMultiple<EndianStorageFormat, T...>(isLittle ? EndianStorageFormat::Little : EndianStorageFormat::Big, values...);
}
/**
* Read multiple values from the stream in little endian format,
* return true on success and false on failure.
*/
template<class... T>
inline bool readMultipleLE(T &...values) {
return this->readMultiple<EndianStorageFormat, T...>(EndianStorageFormat::Little, values...);
}
/**
* Read multiple values from the stream in big endian format,
* return true on success and false on failure.
*/
template<class... T>
inline bool readMultipleBE(T &...values) {
return this->readMultiple<EndianStorageFormat, T...>(EndianStorageFormat::Big, values...);
}
/**
* Read the specified amount of data into a malloc'ed buffer
* which is then wrapped into a MemoryReadStream.
*
* The returned stream might contain less data than requested
* if reading more data failed. This is because of an I/O error or because
* the end of the stream was reached. It can be determined by
* calling err() and eos().
*/
SeekableReadStream *readStream(uint32 dataSize);
/**
* Reads in a terminated string. Upon successful completion,
* return a string with the content of the line, *without*
* the terminating character.
*
* @param terminator The terminating character to use.
* @param len The maximum length to read (includes terminator).
*/
String readString(char terminator = 0, size_t len = String::npos);
/**
* Read a string in Pascal format, that is, one byte is
* string length, followed by string data.
*
* @param transformCR If set (default), then transform \\r into \\n.
*/
Common::String readPascalString(bool transformCR = true);
/** @} */
};
/**
* Interface for a seekable and readable data stream.
*
* @todo Get rid of SEEK_SET, SEEK_CUR, or SEEK_END, use our own constants.
*/
class SeekableReadStream : virtual public ReadStream {
public:
/**
* Obtain the current value of the stream position indicator.
*
* @return The current position indicator, or -1 if an error occurred.
*/
virtual int64 pos() const = 0;
/**
* Obtain the total size of the stream, measured in bytes.
* If this value is unknown or cannot be computed, -1 is returned.
*
* @return The size of the stream, or -1 if an error occurred.
*/
virtual int64 size() const = 0;
/**
* Set the stream position indicator for the stream.
*
* The new position, measured in bytes, is obtained by adding offset bytes
* to the position specified by whence. If whence is set to SEEK_SET, SEEK_CUR,
* or SEEK_END, the offset is relative to the start of the file, the current
* position indicator, or end-of-stream, respectively. A successful call
* to the seek() method clears the end-of-stream indicator for the stream.
*
* @note The semantics of any implementation of this method is
* supposed to match that of ISO C fseek().
*
* @param offset Relative offset in bytes.
* @param whence Seek reference: SEEK_SET, SEEK_CUR, or SEEK_END.
*
* @return True on success, false in case of a failure.
*/
virtual bool seek(int64 offset, int whence = SEEK_SET) = 0;
/**
* Skip the given number of bytes in the stream.
*
* This is equivalent to calling:
* @code
* seek(offset, SEEK_CUR)
* @endcode
* to add the given number of bytes to the current position indicator of the stream.
*
* @return True on success, false in case of a failure.
*/
virtual bool skip(uint32 offset) { return seek(offset, SEEK_CUR); }
/**
* Read at most one less than the number of characters specified
* by @p bufSize from the stream and store them in the string buffer.
*
* Reading stops when the end of a line is reached (CR, CR/LF, or LF),
* and at end-of-stream or error. The newline, if any, is retained (CR
* and CR/LF are translated to ``LF = 0xA = '\n'``). If any characters
* are read and there is no error, a `\0` character is appended
* to end the string.
*
* Upon successful completion, return a pointer to the string. If
* end-of-stream occurs before any characters are read, returns NULL
* and the buffer contents remain unchanged. If an error occurs,
* returns NULL and the buffer contents are indeterminate.
* This method does not distinguish between end-of-stream and error;
* callers must use err() or eos() to determine which occurred.
*
* @note This method is closely modeled after the standard fgets()
* function from stdio.h.
*
* @param s The buffer to store into.
* @param bufSize Size of the buffer.
* @param handleCR If set (default), then CR and CR/LF are handled, as well as LF.
*
* @return Pointer to the read string, or NULL if an error occurred.
*/
virtual char *readLine(char *s, size_t bufSize, bool handleCR = true);
/**
* Read a full line and returns it as a Common::String.
*
* Reading stops when the end of a line is reached (CR, CR/LF, or LF),
* and at end-of-stream or error.
*
* Upon successful completion, return a string with the content
* of the line, *without* the end of a line marker. This method
* does not indicate whether an error occurred. Callers must use
* err() or eos() to determine whether an exception occurred.
*
* @param handleCR If set (default), then CR and CR/LF are handled, as well as LF.
*/
virtual String readLine(bool handleCR = true);
/**
* Print a hexdump of the stream while maintaing position. The number
* of bytes per line is customizable.
*
* @param len Length of this data.
* @param bytesPerLine Number of bytes to print per line (default: 16).
* @param startOffset Shift the shown offsets by the starting offset (default: 0).
*/
void hexdump(int len, int bytesPerLine = 16, int startOffset = 0);
};
/**
* ReadStream mixin subclass that adds non-endian read
* methods whose endianness is set during the stream creation.
*/
class ReadStreamEndian : virtual public ReadStream {
private:
const bool _bigEndian;
public:
/**
* Set the endianness of the read stream.
*
* @param bigEndian If true, create a big endian stream.
* If false, create a little endian stream.
*/
ReadStreamEndian(bool bigEndian) : _bigEndian(bigEndian) {}
/**
* Return true if data is encoded in big endian order.
*/
bool isBE() const { return _bigEndian; }
/**
* Read an unsigned 16-bit word using the stream endianness
* and return it in native endianness.
*/
uint16 readUint16() {
uint16 val;
read(&val, 2);
return (_bigEndian) ? FROM_BE_16(val) : FROM_LE_16(val);
}
/**
* Read an unsigned 32-bit word using the stream endianness
* and return it in native endianness.
*/
uint32 readUint32() {
uint32 val;
read(&val, 4);
return (_bigEndian) ? FROM_BE_32(val) : FROM_LE_32(val);
}
/**
* Read an unsigned 64-bit word using the stream endianness
* and return it in native endianness.
*/
uint64 readUint64() {
uint64 val;
read(&val, 8);
return (_bigEndian) ? FROM_BE_64(val) : FROM_LE_64(val);
}
/**
* Read a signed 16-bit word using the stream endianness
* and return it in native endianness.
*/
FORCEINLINE int16 readSint16() {
return (int16)readUint16();
}
/**
* Read a signed 32-bit word using the stream endianness
* and return it in native endianness.
*/
FORCEINLINE int32 readSint32() {
return (int32)readUint32();
}
/**
* Read a signed 64-bit word using the stream endianness
* and return it in native endianness.
*/
FORCEINLINE int64 readSint64() {
return (int64)readUint64();
}
/**
* Read a 32-bit floating point value using the stream endianness
* and return it in native endianness.
*/
FORCEINLINE float readFloat() {
uint8 val[4];
read(val, 4);
return (_bigEndian) ? READ_BE_FLOAT32(val) : READ_LE_FLOAT32(val);
}
/**
* Read a 64-bit floating point value using the stream endianness
* and return it in native endianness.
*/
FORCEINLINE double readDouble() {
uint8 val[8];
read(val, 8);
return (_bigEndian) ? READ_BE_FLOAT64(val) : READ_LE_FLOAT64(val);
}
};
/**
* SeekableReadStream subclass that adds non-endian read
* methods whose endianness is set during the stream creation.
*/
class SeekableReadStreamEndian : virtual public SeekableReadStream, virtual public ReadStreamEndian {
public:
/**
* Set the endianness of the read stream.
*
* @param bigEndian If true, create a big endian stream.
* If false, create a little endian stream.
*/
SeekableReadStreamEndian(bool bigEndian) : ReadStreamEndian(bigEndian) {}
};
/**
* SeekableReadStreamEndian subclass that wraps around an existing stream.
*
* Altering the position of the substream will affect the position of
* the parent stream, and vice versa.
*/
class SeekableReadStreamEndianWrapper final : virtual public SeekableReadStreamEndian {
protected:
DisposablePtr<SeekableReadStream> _parentStream;
public:
SeekableReadStreamEndianWrapper(SeekableReadStream *parentStream, bool bigEndian, DisposeAfterUse::Flag disposeParentStream = DisposeAfterUse::NO)
: _parentStream(parentStream, disposeParentStream),
SeekableReadStreamEndian(bigEndian),
ReadStreamEndian(bigEndian) {
assert(parentStream);
}
/* Stream APIs */
bool err() const override { return _parentStream->err(); }
void clearErr() override { _parentStream->clearErr(); }
/* ReadStream APIs */
bool eos() const override { return _parentStream->eos(); }
uint32 read(void *dataPtr, uint32 dataSize) override { return _parentStream->read(dataPtr, dataSize); }
/* SeekableReadStream APIs */
int64 pos() const override { return _parentStream->pos(); }
int64 size() const override { return _parentStream->size(); }
bool seek(int64 offset, int whence = SEEK_SET) override { return _parentStream->seek(offset, whence); }
};
/** @} */
} // End of namespace Common
#endif
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