MiscXmodem.rtf

This is MiscXmodem.rtf in view mode; [Download] [Up]

MiscXmodem

Inherits From: Object

Declared In: <misckit/MiscXmodem.h>

Class Description

The MiscXmodem class implements the XMODEM, XMODEM-CRC and XMODEM-1k-CRC serial-line file transfer prtocols. A complete description of these protocols can be found in, XMODEM/YMODEM PROTOCOL REFERENCE -- A compendium of documents describing the XMODEM and YMODEM File Transfer Protocols, Chuck Forsberg, Omen Technology Incorporated, Portland, Oregon, 1988.

Objects of this class do not modify the serial line settings in any way. Before invoking the data transfer methods (sendSerialPort:toStream:, sendStream:toSerialPort:) the serial line must be configured to provide an 8-bit-clean path at the appropriate speed.

MiscXmodem objects are multithreaded but the sub-thread makes no Objective-C calls, so applications using these objects do not have to call objc_setMultithreaded(). Applications should however use cthread_errno() rather than errno, at least while data transfer is in progress.

Instance Variables

BOOL isActive;
BOOL isText;
BOOL use1kPackets;
BOOL isDynamicCheck;
BOOL useCRC;
MiscSerialPort *serialPort;
BOOL serialPortWasSuspended;
int fd;
fd_set checkFdSet;
NXStream *stream;
cthread_t xmodemThread;
port_t messagePort;
port_t replyPort;
id delegate;
unsigned char packetBuffer[1024+5];
unsigned char smallPacketData[1024];
int smallPacketIndex;
int smallPacketCount;
BOOLnewlineFlag;
BOOL isDynamicCheckPacket;
int lastPacketNumber;
int goodPacketCount;
float kbytes;

isActive YES if a data transfer operation in in progress.

isText YES if data will be treated as ASCII text.

use1kPackets YES if data transmission will use large packets.

isDynamicCheck YES if error checking method will be determined dynamically.

useCRC YES if 16-bit CRC error checking method is in use.

MiscSerialPort Serial port object to be used for data transfer.

serialPortWasSuspended Remember whether or not to continue serial port object when data transfer is complete.

fd Serial line file descriptor.

checkFdSet Select(2) file descriptor bitmap.

stream The stream to be used for data transfer.

xmodemThread Data transfer thread.

messagePort Mach port for messages from data transfer thread to main thread.

replyPort Mach port for messages from main thread to data transfer thread.

delegate The object that responds to notification messages.

packetBuffer Current incoming or outgoing packet.

smallPacketData Storage for small packet transmission.

smallPacketIndex Index of next small packet data item to transmit.

smallPacketCount Number of data bytes in smallPacketData.

newlineFlag YES if a newline character needs to be transmitted (text mode data transfers).

isDynamicCheckPacket YES if the next packet will be used to determine the error-checking method.

lastPacketNumber Packet number (0-255) of most recent successfully-received packet.

goodPacketCount Number of packets successfully transferred.

kbytes Number of kbytes of data successfully transferred.

Method Types

Initializing and freeing instances - init
- free

Data transfer options - setFileTypeText:
- xmodemSet1kPackets:
- xmodemSetCheckTypeDynamic:
- xmodemSetCheckTypeCRC:
- isFileTypeText
- xmodemIs1kPackets
- xmodemIsCheckTypeDynamic
- xmodemIsCheckTypeCRC

Data transfer operations - sendToSerialPort:fromStream:
- sendToStream:fromSerialPort:
- isActive

Delegate - setDelegate:
- delegate
- didTransferPacket:kbytes:
- didRetryNumber:
- didFinish:

Instance Methods

delegate
-delegate

Returns the object's delegate.

free
-free

Cancels the data transfer operation, if any, and frees the object.

init
-init

Initializes a new MiscXmodem instance. The default settings are text files, 1k packets, and dynamic selection of error checking method.

setDelegate:
-setDelegate:id

Sets the object's delegate. Delegate objects are sent messages describing the progress of data transfer operations.

See also: - didFinish:, - didTransferPacket:kbytes:, - didRetryNumber:

didFinish:
-didFinish:(const char *)failureCode

Sent to the delegate when data transfer operation completes. If the transfer completed successfully, the failureCode string will be empty (""), otherwise the string will describe the condition that caused the transfer to fail.

didRetryNumber:
-didRetryNumber:(int)anInt

Sent to the delegate when the data transfer operation retries a packet transfer. The argument is the number of times that the current packet has been retried.

didTransferPacket:kbytes:
-didTransferPacket:(int)anInt kbytes:(float)aFloat

Sent to the delegate when the a packet is successfully transferred. The arguments are the number of packets and the amount of data (in kbytes) that have been transferred so far.

xmodemIs1kPackets
-(BOOL)xmodemIs1kPackets

Returns YES if data transmission will use 1k packets, NO if it will use only 128-byte packets. The default value is YES.