Presentation On Ab Initio Custom Component
By Vineet Agrawal
[email protected]
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Contents
•
Overview
•
Syntax of MPC file
•
Writing A Program Specification File
•
Steps To Create New Component
•
Detailed Descriptions of Attributes & Variables
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Overview • Program specification files provide the Co>Operating System with the information it needs to run program or shell script. • Program specification files should be with .mpc extensions. • All program specification files must start with
• The line is followed by a series of attribute: value lines that describe the attributes of program.
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Syntax Program specification file uses the following syntax [ label: label ] [ author: author-name ] [ version: version-number ] [ comment: comment ] image: path [ exit: code ] [ port: type direction name [location] [ordering] [fan-preference] [min-flows] [max-flows] [record-format] ] [ environment : env-variable value ] [ argument: literal value1 [value2 ...] ] [ argument: flow portname ] [ argument: partition ] [ argument: depth ]
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[ argument: file filename ] [ argument: expression file filename ] [ argument: expression string ] [ argument: transform file filename ] [ argument: transform string ] [ parameter: placement name type default-value Þ description [restrictions] ] [ metadata type: dest-portname = {source-portname | value} ]
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Writing a program specification file • Must include the line and the image line, all the other lines are optional. • Can use as many port, argument, parameter, and metadata type lines as you need to describe your particular program. • Comments in a program specification file are denoted by the following: Lines that start with # From // to the end of the line From /* to */ To write a program specification file in the Component Organiser: 1.
In the GDE, open the Component Organiser.
2.
Right-click My Components.
3.
From the shortcut menu, choose New > Program.
A New Component icon appears under My Components.
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4.
Do one of the following:
Enter a name in the New Component icon. Press Enter to accept New Component as the name. 5.
Right click the New Component icon.
A pop-up menu appears. 6.
From the pop-up menu, choose Edit As text.
The Edit Program Component window opens. 7. Write your own program specification file by editing the template in the window.
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Steps to Create New Component Step 1
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Step 2
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Step 3
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Detailed Descriptions of Attribute & Variables Label Syntax: label: label This line specifies the name you want to appear for the component in the Component Organiser and on the component icon in the GDE. Example: Lebel: “This Is My Own Component”
Mpname mpname: "mp component name"
Author Syntax: author: "Your Name" This line specifies the author's name that appears on the Properties Description tab of the Properties dialog box in the GDE. Example: author: “Vineet Agrawal”
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Version Syntax: version: version-number This line specifies the version number that appears on the Properties Description tab of the Properties dialog box in the GDE. For built-in components, use “Built-in :” Examples: version: "1.0"
Comment Syntax: comment: comment This line specifies the comment that appears in the GDE in two places: • On the Properties Description tab of the Properties dialog box • In the Description Panel of the Component Organizer when you select the component Examples: comment: "Your Description Here"
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Image Syntax: image: "path" This line specifies the path for the executable program or script for this component; path represents this path. Specify an absolute or relative path. A relative path is relative to the current search path specified in the PATH configuration variable. Supply one image line in the program specification file. This is the only line other than the line that you must have in the program specification file. When the Co>Operating System runs the program, it uses the same path on all processing nodes. If the Co>Operating System does not find the program on a processing node by following that path, it copies the program from the control node to a cache directory on the processing node, runs it, and saves it for future use. Examples: image: "name-of-executable" NOTE: Enclose path in double quotes.
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Exit Syntax: exit: code This line specifies the integer exit code that indicates a successful termination. Use a specific integer or one of the following: Any negative non_positive
positive
even non_negative
odd
The default is 0. Examples: exit: negative
Port Port lines define the ports that the component supports. Syntax: port : type direction name [ordering ] [location ] [fan-preference ] [min-flows ] [max-flows ] [record-format] Ports in Ab Initio components represent the input/output behaviour of program.
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1. type The type variable specifies one of four different types of ports, as follows: • std - Invokes program with the standard input, standard output, or standard error already connected. In order to use a std port, program must read sequentially from its standard input flow or write sequentially to the standard output or standard error flow, without seeking. The .mpc file needs no additional lines for a std port. • file - Passes a path to program. In order to use a file port, program must accept a path argument on the command line, and either read a file without modifying it (for an in port) or write a file with that path (for an out port). For an in port, your program may open the file any number of times, and it may seek in the file. For an out port, your program must open the file at least once, or must create it in some other way. The .mpc file should contain a line of the following form for each file port: argument: flow portname
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• npipe- Creates a named pipe or file and passes its path to your program. In order to use an npipe port, your program must accept a path argument on the command line and perform sequential I/O on it. For an in port, your program must open the file for reading exactly once and then read sequentially to the end without seeking or writing in the file. For an out port, your program must open the file for writing exactly once, and then write sequentially without seeking or reading in the file. Ports of the npipe type allow the graph to run faster, due to the pipeline parallelism they support. The .mpc file should contain a line of the following form for each npipe port: argument: flow portname •
soc - The SOC interface is used by Ab Initio built-in components
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2. direction Specifies the direction of the flow for a port. direction in out err
Port input port or stdin output port or stdout Stderr
3. name Specifies the name of the port. For example, the input port is usually named in.
4. location Specifies on which side of the component icon you want the port to appear in the GDE. Choose one of the following: top bottom left right
5. ordering Controls whether or not the GDE may reorder multiple flows connected to a port: • If you specify ordered, the GDE does not reorder multiple flows connected to the port. • If you do not specify ordered, the GDE reorders port connections for readability. • Ordered indicates ordering of attached flows is important (e.g. input to CONCAT) (default NO)
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6. fan-preference Specifies the type of flow the GDE creates when you connect a flow to the port. The fan-preference option works as follows: If you specify multiple, the GDE creates fan-in flows, fan-out flows, or all-to-all flows where appropriate. If you do not specify multiple, the GDE creates straight flows. 7.
min-flows and max-flows
Specifies the minimum and maximum number of flow partitions you can connect to a port. - use 0 for mintaps to indicate the port need not be connected. - use a big number like 99999 for maxtaps to indicate no limit. - defaults are 1 and infinity if not given This is used to guess flow patterns.
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8. record-format The default is for ports to propagate their metadata from the ports to which they connect. metadata is quoted metadata default, either "=string" or "&remotefilepath" or "Llocalfilepath" Examples: port: soc in in ordered 1 99999 port: soc out out 1 1 port: soc out log 0 1 port: npipe in indat ordered left multiple 1 1 "=string('\n')"
Environment Syntax: environment: "env-variable value" NOTE: Enclose env-variable value in double quotes. This line lets you direct the Co>Operating System to set the environment variable named by env-variable to value in the runtime environment of each partition of the component. Examples: environment: “BB_DQ_COUNT 10”
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Parameter Used by the GDE to construct "mp custom" commands in the job script. The "mp custom" line will contain the parameters in the specified order. Syntax: parameter: 
