#include <basicio.hpp>
Inheritance diagram for Exiv2::MemIo:
Public Member Functions | |
Creators | |
MemIo () | |
Default constructor that results in an empty object. | |
MemIo (const byte *data, long size) | |
Constructor that accepts a block of memory. A copy-on-write algorithm allows read operations directly from the original data and will create a copy of the buffer on the first write operation. | |
~MemIo () | |
Destructor. Releases all managed memory. | |
Manipulators | |
virtual int | open () |
Memory IO is always open for reading and writing. This method therefore only resets the IO position to the start. | |
virtual int | close () |
Does nothing on MemIo objects. | |
virtual long | write (const byte *data, long wcount) |
Write data to the memory block. If needed, the size of the internal memory block is expanded. The IO position is advanced by the number of bytes written. | |
virtual long | write (BasicIo &src) |
Write data that is read from another BasicIo instance to the memory block. If needed, the size of the internal memory block is expanded. The IO position is advanced by the number of bytes written. | |
virtual int | putb (byte data) |
Write one byte to the memory block. The IO position is advanced by one byte. | |
virtual DataBuf | read (long rcount) |
Read data from the memory block. Reading starts at the current IO position and the position is advanced by the number of bytes read. | |
virtual long | read (byte *buf, long rcount) |
Read data from the memory block. Reading starts at the current IO position and the position is advanced by the number of bytes read. | |
virtual int | getb () |
Read one byte from the memory block. The IO position is advanced by one byte. | |
virtual void | transfer (BasicIo &src) |
Clear the memory block and then transfer data from the src BasicIo object into a new block of memory. | |
virtual int | seek (long offset, Position pos) |
Move the current IO position. | |
virtual byte * | mmap (bool=false) |
Allow direct access to the underlying data buffer. The buffer is not protected against write access in any way, the argument is ignored. | |
virtual int | munmap () |
Remove a mapping established with mmap(). If the mapped area is writeable, this ensures that changes are written back. | |
Accessors | |
virtual long | tell () const |
Get the current IO position. | |
virtual long | size () const |
Get the current memory buffer size in bytes. | |
virtual bool | isopen () const |
Always returns true. | |
virtual int | error () const |
Always returns 0. | |
virtual bool | eof () const |
Returns true if the IO position has reach the end, otherwise false. | |
virtual std::string | path () const |
Returns a dummy path, indicating that memory access is used. | |
virtual BasicIo::AutoPtr | temporary () const |
Returns a temporary data storage location. Currently returns an empty MemIo object, but callers should not rely on this behavior since it may change. |
|
Constructor that accepts a block of memory. A copy-on-write algorithm allows read operations directly from the original data and will create a copy of the buffer on the first write operation.
|
|
Does nothing on MemIo objects.
Implements Exiv2::BasicIo. |
|
Read one byte from the memory block. The IO position is advanced by one byte.
Implements Exiv2::BasicIo. |
|
Allow direct access to the underlying data buffer. The buffer is not protected against write access in any way, the argument is ignored.
Implements Exiv2::BasicIo. |
|
Remove a mapping established with mmap(). If the mapped area is writeable, this ensures that changes are written back.
Implements Exiv2::BasicIo. |
|
Memory IO is always open for reading and writing. This method therefore only resets the IO position to the start.
Implements Exiv2::BasicIo. |
|
Write one byte to the memory block. The IO position is advanced by one byte.
Implements Exiv2::BasicIo. |
|
Read data from the memory block. Reading starts at the current IO position and the position is advanced by the number of bytes read.
Implements Exiv2::BasicIo. |
|
Read data from the memory block. Reading starts at the current IO position and the position is advanced by the number of bytes read.
Implements Exiv2::BasicIo. |
|
Move the current IO position.
Implements Exiv2::BasicIo. |
|
Get the current memory buffer size in bytes.
Implements Exiv2::BasicIo. |
|
Get the current IO position.
Implements Exiv2::BasicIo. |
|
Returns a temporary data storage location. Currently returns an empty MemIo object, but callers should not rely on this behavior since it may change.
Implements Exiv2::BasicIo. |
|
Clear the memory block and then transfer data from the src BasicIo object into a new block of memory. This method is optimized to simply swap memory block if the source object is another MemIo instance. The source BasicIo instance is invalidated by this operation and should not be used after this method returns. This method exists primarily to be used with the BasicIo::temporary() method.
Implements Exiv2::BasicIo. |
|
Write data that is read from another BasicIo instance to the memory block. If needed, the size of the internal memory block is expanded. The IO position is advanced by the number of bytes written.
Implements Exiv2::BasicIo. |
|
Write data to the memory block. If needed, the size of the internal memory block is expanded. The IO position is advanced by the number of bytes written.
Implements Exiv2::BasicIo. |