#include <PacketizedDataIO.h>
Inheritance diagram for PacketizedDataIO:
Public Types | |
| enum | { IO_SEEK_SET = 0, IO_SEEK_CUR, IO_SEEK_END, NUM_IO_SEEKS } |
| Values to pass in to DataIO::Seek()'s second parameter. More... | |
Public Member Functions | |
| PacketizedDataIO (const DataIORef &slaveIO, uint32 maxTransferUnit=MUSCLE_NO_LIMIT) | |
| Constructor. | |
| const DataIORef & | GetSlaveIO () const |
| Returns a reference to our underlying DataIO object. | |
| void | SetSlaveIO (const DataIORef &sio) |
| Sets our underlying Data I/O object. | |
| uint32 | GetMaxTransferUnit () const |
| Returns the maximum "packet size" we will be willing to send or receive. | |
| virtual int32 | Read (void *buffer, uint32 size) |
| Tries to place (size) bytes of new data into (buffer). | |
| virtual int32 | Write (const void *buffer, uint32 size) |
| Takes (size) bytes from (buffer) and pushes them in to the outgoing I/O stream. | |
| virtual status_t | Seek (int64 offset, int whence) |
| Seek to a given position in the I/O stream. | |
| virtual int64 | GetPosition () const |
| Should return the current position, in bytes, of the stream from its start position, or -1 if the current position is not known. | |
| virtual uint64 | GetOutputStallLimit () const |
| Returns the max number of microseconds to allow for an output stall, before presuming that the I/O is hosed. | |
| virtual void | FlushOutput () |
| Flushes the output buffer, if possible. | |
| virtual void | Shutdown () |
| Closes the connection. | |
| virtual const SocketRef & | GetSelectSocket () const |
| If this DataIO is usable with select(), this method should return the SocketRef object containing the file descriptor to select on for this DataIO. | |
| virtual int64 | GetLength () |
| Convenience method: Determines the length of this DataIO stream by Seek()'ing to the end of the stream, recording the current seek position, and then Seek()'ing back to the previous position in the stream. | |
| virtual bool | HasBufferedOutput () const |
| Optional: If your DataIO subclass is holding buffered data that it wants to output as soon as possible but hasn't been able to yet, then override this method to return true, and that will cause FlushBufferedOutput() to be called ASAP. | |
| virtual void | WriteBufferedOutput () |
| Optional: If this DataIO is holding any buffered output data, this method should be implemented to Write() as much of that data as possible. | |
| virtual status_t | GetReadByteTimeStamp (int32 whichByte, uint64 &retStamp) const |
| Optional interface for returning information on when a given byte returned by the previous Read() call was received. | |
| uint32 | WriteFully (const void *buffer, uint32 size) |
| Convenience method: Calls Write() in a loop until the entire buffer is written, or until an error occurs. | |
| uint32 | ReadFully (void *buffer, uint32 size) |
| Convenience method: Calls Read() in a loop until the entire buffer is written, or until an error occurs. | |
| void | IncrementRefCount () const |
| Increments the counter and returns true iff the new value is zero. | |
| bool | DecrementRefCount () const |
| Decrements the counter and returns true iff the new value is zero. | |
| void | SetManager (AbstractObjectManager *manager) |
| Sets the recycle-pointer for this object. | |
| AbstractObjectManager * | GetManager () const |
| Returns this object's current recyler pointer. | |
| uint32 | GetRefCount () const |
| Returns this object's current reference count. | |
a TCPSocketDataIO) in order to make it appear like a packet-based I/O object (e.g. a UDPSocketDataIO) to the calling code.
It does this by inserting message-length fields into the outgoing byte stream, and parsing message-length fields from the incoming byte stream, so that data will be returned in Read() in the same chunk sizes that it was originally passed in to Write() on the other end. Note that this does change the underlying byte-stream protocol, so the receiver must be aware of the change (typically by having the receiver wrap his DataIO object in a PacketizedDataIO object also)
You might use this class to simulate a lossless UDP connection by "tunneling" UDP over TCP.
Definition at line 24 of file PacketizedDataIO.h.
anonymous enum [inherited] |
Values to pass in to DataIO::Seek()'s second parameter.
| PacketizedDataIO::PacketizedDataIO | ( | const DataIORef & | slaveIO, | |
| uint32 | maxTransferUnit = MUSCLE_NO_LIMIT | |||
| ) |
Constructor.
| void PacketizedDataIO::SetSlaveIO | ( | const DataIORef & | sio | ) | [inline] |
Sets our underlying Data I/O object.
Use with caution!
Definition at line 40 of file PacketizedDataIO.h.
| uint32 PacketizedDataIO::GetMaxTransferUnit | ( | ) | const [inline] |
Returns the maximum "packet size" we will be willing to send or receive.
Defaults to MUSCLE_NO_LIMIT.
Definition at line 43 of file PacketizedDataIO.h.
| virtual int32 PacketizedDataIO::Read | ( | void * | buffer, | |
| uint32 | size | |||
| ) | [virtual] |
Tries to place (size) bytes of new data into (buffer).
Returns the actual number of bytes placed, or a negative value if there was an error.
| buffer | Buffer to write the bytes into | |
| size | Number of bytes in the buffer. |
Implements DataIO.
| virtual int32 PacketizedDataIO::Write | ( | const void * | buffer, | |
| uint32 | size | |||
| ) | [virtual] |
Takes (size) bytes from (buffer) and pushes them in to the outgoing I/O stream.
Returns the actual number of bytes read from (buffer) and pushed, or a negative value if there was an error.
| buffer | Buffer to read the bytes from. | |
| size | Number of bytes in the buffer. |
Implements DataIO.
| virtual status_t PacketizedDataIO::Seek | ( | int64 | offset, | |
| int | whence | |||
| ) | [inline, virtual] |
Seek to a given position in the I/O stream.
May not be supported by a DataIO subclass, in which case B_ERROR will always be returned.
| offset | Byte offset to seek to or by (depending on the next arg) | |
| whence | Set this to IO_SEEK_SET if you want the offset to be relative to the start of the stream; or to IO_SEEK_CUR if it should be relative to the current stream position, or IO_SEEK_END if it should be relative to the end of the stream. |
Implements DataIO.
Definition at line 47 of file PacketizedDataIO.h.
| virtual uint64 PacketizedDataIO::GetOutputStallLimit | ( | ) | const [inline, virtual] |
Returns the max number of microseconds to allow for an output stall, before presuming that the I/O is hosed.
Default implementation returns MUSCLE_TIME_NEVER, aka no limit.
Reimplemented from DataIO.
Definition at line 49 of file PacketizedDataIO.h.
| virtual void PacketizedDataIO::FlushOutput | ( | ) | [inline, virtual] |
Flushes the output buffer, if possible.
For some implementations, this is a no-op. For others (e.g. TCPSocketDataIO) this can be called to reduced latency of outgoing data blocks.
Implements DataIO.
Definition at line 50 of file PacketizedDataIO.h.
| virtual void PacketizedDataIO::Shutdown | ( | ) | [inline, virtual] |
Closes the connection.
After calling this method, the DataIO object should not be used any more.
Implements DataIO.
Definition at line 51 of file PacketizedDataIO.h.
References ByteBuffer::Clear(), and Ref< Item >::Reset().
| virtual const SocketRef& PacketizedDataIO::GetSelectSocket | ( | ) | const [inline, virtual] |
If this DataIO is usable with select(), this method should return the SocketRef object containing the file descriptor to select on for this DataIO.
If this DataIO isn't usable with select(), then this method should return GetNullSocket().
Note that the only thing you are allowed to do with the returned file descriptor is pass it to select(). For all other operations, use the appropriate methods in the DataIO interface. If you attempt to do any other I/O operations on this file descriptor directly, the results are non-portable and undefined and will probably break your program.
Implements DataIO.
Definition at line 52 of file PacketizedDataIO.h.
| virtual int64 PacketizedDataIO::GetLength | ( | ) | [inline, virtual] |
Convenience method: Determines the length of this DataIO stream by Seek()'ing to the end of the stream, recording the current seek position, and then Seek()'ing back to the previous position in the stream.
Of course this only works with DataIOs that support seeking and have a fixed length.
Reimplemented from DataIO.
Definition at line 53 of file PacketizedDataIO.h.
| virtual bool PacketizedDataIO::HasBufferedOutput | ( | ) | const [inline, virtual] |
Optional: If your DataIO subclass is holding buffered data that it wants to output as soon as possible but hasn't been able to yet, then override this method to return true, and that will cause FlushBufferedOutput() to be called ASAP.
Default implementation always returns false.
Reimplemented from DataIO.
Definition at line 55 of file PacketizedDataIO.h.
References ByteBuffer::GetNumBytes().
| virtual void PacketizedDataIO::WriteBufferedOutput | ( | ) | [inline, virtual] |
Optional: If this DataIO is holding any buffered output data, this method should be implemented to Write() as much of that data as possible.
Default implementation is a no-op.
Reimplemented from DataIO.
Definition at line 56 of file PacketizedDataIO.h.
| virtual status_t DataIO::GetReadByteTimeStamp | ( | int32 | whichByte, | |
| uint64 & | retStamp | |||
| ) | const [inline, virtual, inherited] |
Optional interface for returning information on when a given byte returned by the previous Read() call was received.
Not implemented by default, and not implemented by any of the standard MUSCLE DataIO subclasses. (Used by an LCS dataIO class that needs precision timing)
| whichByte | Index of the byte in the previously returned read-buffer that you are interested in. | |
| retStamp | On success, this value is set to the timestamp of the byte. |
Reimplemented in FailoverDataIO, MultiDataIO, and XorDataIO.
Definition at line 114 of file DataIO.h.
Referenced by MultiDataIO::GetReadByteTimeStamp(), and FailoverDataIO::GetReadByteTimeStamp().
| uint32 DataIO::WriteFully | ( | const void * | buffer, | |
| uint32 | size | |||
| ) | [inherited] |
Convenience method: Calls Write() in a loop until the entire buffer is written, or until an error occurs.
This method should only be used in conjunction with blocking I/O; it will not work reliably with non-blocking I/O.
| buffer | Pointer to the first byte of the buffer to write data from. | |
| size | Number of bytes to write |
| uint32 DataIO::ReadFully | ( | void * | buffer, | |
| uint32 | size | |||
| ) | [inherited] |
Convenience method: Calls Read() in a loop until the entire buffer is written, or until an error occurs.
This method should only be used in conjunction with blocking I/O; it will not work reliably with non-blocking I/O.
| buffer | Pointer to the first byte of the buffer to place the read data into. | |
| size | Number of bytes to read |
| void RefCountable::IncrementRefCount | ( | ) | const [inline, inherited] |
Increments the counter and returns true iff the new value is zero.
Thread safe.
Definition at line 32 of file RefCount.h.
References AtomicCounter::AtomicIncrement().
| bool RefCountable::DecrementRefCount | ( | ) | const [inline, inherited] |
Decrements the counter and returns true iff the new value is zero.
Thread safe.
Definition at line 35 of file RefCount.h.
References AtomicCounter::AtomicDecrement().
| void RefCountable::SetManager | ( | AbstractObjectManager * | manager | ) | [inline, inherited] |
Sets the recycle-pointer for this object.
If set to non-NULL, this pointer is used by the ObjectPool class to recycle this object when it is no longer in use, so as to avoid the overhead of having to delete it and re-create it later on. The RefCountable class itself does nothing with this pointer. Default value is NULL.
| manager | Pointer to the new manager object to use, or NULL to use no manager. |
Definition at line 44 of file RefCount.h.
| uint32 RefCountable::GetRefCount | ( | ) | const [inline, inherited] |
Returns this object's current reference count.
Note that the value returned by this method is volatile in multithreaded environments, so it may already be wrong by the time it is returned. Be careful!
Definition at line 54 of file RefCount.h.
References AtomicCounter::GetCount().
1.5.1