Due to a lot of different reasons, this library is no longer supported. If you're interested in this topic, a more robust and complete implementation based on Swift is available.
Years ago, I used to use a product on the IBM mainframe called CMS Pipelines. It is an awesome record-based filtering system that lets you filter and change records as they flow through the pipeline. Having left IBM some years ago, I no longer had access to a mainframe system where I could use this tool.
There is currently a NetREXX-based partial implementation of CMS Pipelines called njPipes, but given that I lack 1) a NetREXX installation, and 2) the inclination to find and install one, I thought that it would be an interesting exercise to try to write one in pure Java.
I had a false start a few years ago when I realised that I didn't fully understand the whole record delay mechanism, but about 6 months ago, I had a situation arise where an implementation of Pipes would have been just the ticket. Obviously that situation has long since passed, but it sowed the seed that I needed, and I re-downloaded all the documentation that I needed.
While the implementation that I have is not complete, it definitely has the makings of a full featured implementation. I have tried to stick as closely as possible to the original implementation (notwithstanding the obvious Java/Rexx and EBCDIC/ASCII differences). At times this can be hard because I don't have a mainframe implementation to check my work with, but through careful reading of the manuals, I believe that I have created a very faithful reproduction.
There are several features that are worth pointing out, I think:
- The dispatcher is complete with one exception: stall detection. I have designed the stall detection mechanism, but have not yet implemented it.
- Single- and Multi-stream pipelines are fully supported.
- Callpipe has been implemented (but probably needs a little bit of testing). Addpipe has been designed but not yet implemented.
- The dispatcher has the ability to generate events, which can be "listened to". Eventually, this mechanism will be used to implement RUNPIPE EVENTS.
- Full support for MSGLEVEL, TRACE, STAGESEP, LISTCMD, LISTERR, et al (at both the pipe and stage level)
- While I have done very little performance tuning, I have been very conscious of throughput during the whole design and development process.
The list below gives a taste for which stages have been implemented:
- <
-
-
- ABBREV
- ADDRDW
- AGGRC
- BETWEEN
- BUFFER
- CHANGE
- CHOP
- COMMAND
- CONSOLE
- COUNT
- DUPLICATE
- FANIN
- FANINANY
- FANOUT
- GATE
- HOLE
- HOSTID
- HOSTNAME
- LITERAL
- LOCATE
- NLOCATE
- NOEOFBACK
- NOT
- QUERY
- REVERSE
- SPECS
- SPLIT
- STRLITERAL
- TAKE
Download pipe.jar from github.com, and use a command like this one:
java -jar pipe.jar "literal hello there | cons"
Alternatively, if you want to use it from within your existing java program, you could do something like:
new Pipe().run("literal hello there | > blah");
Although I have many testcases for each of the stages, there is obviously some chance that bugs have slipped through. If you believe that you have found a bug, or a difference to the mainframe implementation, please email me.