ITK Programmer's Guide

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These routines can be used to accurately measure elapsed time in some critical code portions.
Under MacOS, these routines use the Time Manager to get a high level of accuracy (up to the millisecond).

ITK_TimerStart
Syntax:	timerRef := ITK_TimerStart
Description:	Start a timer and returns a reference to it. These reference will be used when calling ITK_TimerLap and ITK_TimerStop.
Params:	In/Out Parameter Type     Example or note <- timerRef Longint Timer reference number
Example:	$timer := ITK_TimerStart ... $elapsedTime := ITK_TimerStop($timer)

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ITK_TimerLap
Syntax:	lapTime := ITK_TimerLap(timerRef)
Description:	Returns the number of milliseconds since ITK_TimerStart was called without stopping the timer.
Params:	In/Out Parameter Type     Example or note -> timerRef Longint Timer reference number As returned by ITK_TimerStart <- lapTime Longint Elapsed time in milliseconds
Example:	$timer := ITK_TimerStart ... $lapTime1 := ITK_TimerLap($timer) ... $lapTime2 := ITK_TimerLap($timer) ... $totalTime := ITK_TimerStop($timer)

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ITK_TimerStop
Syntax:	totalTime := ITK_TimerStop(timerRef)
Description:	Returns the number of milliseconds since ITK_TimerStart was called and then stops the timer.
Note:	After calling ITK_TimerStop, the Timer Reference number returned by ITK_TimerStart is not valid anymore.
Params:	In/Out Parameter Type     Example or note -> timerRef Longint Timer reference number As returned by ITK_TimerStart <- totalTime Longint Elapsed time in milliseconds
Example:	$timer := ITK_TimerStart ... $totalTime := ITK_TimerStop($timer)

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ITK's IPC routines are useful to exchange data between processes through communications channels. These channels are memory based to provide speed efficient communications.

The number of channels and the number of messages queued in a channel are limited by the available memory.

ITK_NbIPCMsg
Syntax:	nbMsg := ITK_NbIPCMsg(ipcChannel)
Description:	Returns the number of messages currently stored on the specified IPC channel.
Note:	IPC channel number are used to create as many IPC channels as you need. For example, you can use the Current Process instruction in 4D language to allocate one IPC channel for each 4D process or use any other channel numbering.
Params:	In/Out Parameter Type     Example or note -> ipcChannel Longint IPC Channel Number see note above. <- nbMsg Longint Number of messages stored in this IPC channel.
Example:	While (ITK_NbIPCMsg(1)>0) ` process IPC messages ... End While

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ITK_SendIPCMsg
Syntax:	ITK_SendIPCMsg(ipcChannel;message)
Description:	Sends a message on the specified IPC channel. The message will be stored in the channel message queue.
Note:	IPC channel number are used to create as many IPC channels as you need. For example, you can use the Current Process instruction in 4D language to allocate one IPC channel for each 4D process or use any other channel numbering.
Params:	In/Out Parameter Type     Example or note -> ipcChannel Longint IPC Channel Number see note above. -> message Text Message to send in the above channel
Example:	ITK_SendIPCMsg(1;"quit")

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ITK_RcvIPCMsg
Syntax:	message := ITK_RcvIPCMsg(ipcChannel;option)
Description:	Reads a message from the specified IPC channel. If no message is available, returns an empty string. The option parameter can be used to keep the message in the IPC channel queue. In that case, the same message will be returned on the next call to ITK_RcvIPCMsg.
Note:	IPC channel number are used to create as many IPC channels as you need. For example, you can use the Current Process instruction in 4D language to allocate one IPC channel for each 4D process or use any other channel numbering.
Params:	In/Out Parameter Type     Example or note -> ipcChannel Longint IPC Channel Number see note above. -> option Longint     0 = default behaviour 1 = keep message in channel queue <- message Text Receive message will be empty if no message available on the requested IPC channel.
Example:	$msg := ITK_RcvIPCMsg(1;0) If ($msg = "quit") QUIT 4D End If

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ITK_ResetIPCMsg
Syntax:	ITK_ResetIPCMsg(ipcChannel)
Description:	Removes all the messages stored on the specified IPC channel.
Note:	IPC channel number are used to create as many IPC channels as you need. For example, you can use the Current Process instruction in 4D language to allocate one IPC channel for each 4D process or use any other channel numbering.
Params:	In/Out Parameter Type     Example or note -> ipcChannel Longint IPC Channel Number see note above.
Example:	ITK_ResetIPCMsg(1)

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ITK_PictSize
Syntax:	pictSize := ITK_PictSize(pict; top; left; bottom; right; type)
Description:	This routines extracts size informations from a given picture.
Params:	In/Out Parameter Type     Example or note -> pict Picture         -> top Longint Top coordinates of the picture     -> left Longint Left coordinate of the picture     -> bottom Longint Bottom coordinate of the picture     -> right Longint Right coordinate of the picture     -> type Longint type of picture 0 = Mac style PICT 1 = GIF image 2 = JPEG image <- pictSize Longint Size (in bytes) of the picture
Example:	$size := ITK_PictSize($pict;$top;$left;$bottom;$right;$type) $height := $bottom-$top $width := $right-$left

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ITK_PictSave
Syntax:	error := ITK_PictSave(pict; filePath)
Description:	Saves the content of a picture field or variable into a file. If the picture is encoded in the GIF format, a standard GIF file will be saved. If the picture contains a JPEG portion, this portion will be save as a JPEG/JFIF file. Otherwise, the picture will be saved as a standard Picture (PICT).
Params:	In/Out Parameter Type     Example or note -> pict Picture         -> filePath String File pathname     <- error Longint OS error code
Example:	$err := ITK_PictSave($pict;"MyHD:MyFolder:MyPict")

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ITK_PictRead
Syntax:	pict := ITK_PictRead(filePath)
Description:	Reads a picture file (PICT, GIF or JFIF/JPEG) and returns it as a 4D pict.
Params:	In/Out Parameter Type     Example or note -> filePath String Filepath of the Picture file to read     <- pict Picture Picture read from file. If an error occured, this picture will have its size set to 0.
Example:	$pict := ITK_PictRead("MyHD:MyFolder:MyPict") $err := ITK_TCPSendPict($stream; $pict)

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ITK_ICMPEcho
Syntax:	time := ITK_ICMPEcho(IPaddr; timeout; size)
Description:	This routines sends an "ICMP Echo" packet to the remote IP address and measures the time needed for the echo to come back. It is an equivallent to the famous "ping" function.
Params:	In/Out Parameter Type     Example or note -> IPaddr Longint Remote host IP address As returned by ITK_Name2Addr. -> timeout Longint Timeout in seconds     -> size Longint Size of the ICMP Echo packet to send. 0 will use a default size of 64 bytes. <- result Longint Measured time in milliseconds Negative values indicate that an error occured.
Example:	$pingtime := ITK_ICMPEcho(ITK_Name2Addr("www.internet-toolkit.com");2000;64)

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$file := ITK_OpenFile("C:\MyFile.TXT")
If ($file#0)
  RECEIVE PACKET($file;$data;32000)
  ...
  CLOSE DOCUMENT($file)
End If

$err := ITK_SetPriority(4) ` go in Idle mode

` Set 4D's at least in "normal" priority
If (ITK_GetPriority<9)
  $err := ITK_SetPriority(9)
End If

$myBlob := ITK_Pict2Blob($myBlob)

$myBlob := ITK_Pict2Blob($myPict) ` return a copy (uses more memory)
$myBlob := ITK_Pict2Blob($myPict;1) ` "transfers" the pict into a blob, the original pict is emptied