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Sean Connelly · Nov 16

Hey Paul,

Half agree if the OP requirements turn out to be a file to file use case.

If not, I wanted to defend the record mapper solution a little so as not to put off other readers from this approach.

As an example, I recently implemented a solution that had a million line CSV file. This would generate around 300,000 messages from a complex mapping. Each record was individually passed into a DTL which in turn produced a master file update message. These were then pushed into the local EPR (as per the EPR's requirements).

Yes, many messages, but not what I would call an overhead when taken into context of the frequency and need for M16 messages.

Bottom line, the solution I selected was the most maintainable solution. Almost zero glue code to go wrong and all maintanence managed inside DTL's. This is exactly what the record mapper was designed for.

Sean Connelly · Nov 15

Looks like there are some conflicts in the points...

Java Native has 2 and then 3 points.

Here the LLM has 3, 4 and 6 points...

LLM AI or LangChain usage: Chat GPT, Bard and others - 3
LLM AI or LangChain usage: Chat GPT, Bard and others - 4 points
Collect 6 bonus expert points for building a solution that uses LangChain libs or Large Language Models (LLM)

Sean Connelly · Oct 24

I recommend using two terminals to experiment with locking and unlocking various globals. By observing the lock table during this process, you'll gain a clearer understanding of lock behavior across different processes.

Next, consider what you're aiming to lock. In other words, identify what you're trying to safeguard and against which potential issues. For instance, is the variable "loc" unique? Could two processes obtain the same value for "loc"? Without seeing the preceding code, it's challenging to discern if "loc" was assigned manually or via `$Increment`. Remember, using `$Increment` eliminates the need for locks in most cases.

Also, reevaluate your decision to use transactions for a single global write. If your goal is transactional integrity, think about which additional global writes should be encompassed in that transaction. For example, if "obj" is defined just before this code with a `%Save()` method, then include that save in the same transaction. Otherwise, a system interruption between the two actions can lead to an unindexed object, compromising data integrity.

I strongly advise revisiting the documentation multiple times and actively experimenting with these concepts. While these techniques offer significant advantages, their efficacy diminishes if not executed properly.

Sean Connelly · Oct 23

Hi Rochdi,

As mentioned, always ensure locks are explicitly released after use.

Reading between the lines a little, you might find these following points useful...

  • Locks don't actually "seal" a global node; they're advisory.
  • Any rogue process can still write to a locked global.
  • Another process is only deterred from writing to a global if it also attempts to obtain a lock and fails. The developer is responsible to implement this and handle failed locks in every location a write happens.
  • Without a timeout, a process can hang indefinitely due to a lock. You could argue its good practice to use a timeout.
  • If you implement a timeout, always verify the value of $test to ensure you've acquired the lock and not just timed out.
  • $Increment() is useful for creating sequenced ordinal ID's that are always unique, without the need for locks. This is true for high-concurrency solutions.

(If you're using locks only to make the key "inc" unique, then consider using $increment and forgo the locks.)

Sean Connelly · Oct 23

Hi Yone,

I would keep it simple, avoid unpacking JSON here and make pResponse a generic Ens.StreamContainer

Something like this should do it...

set tSC=httpRequest.Post(URL,0)
if $$$ISERR(tSC) return tSC  //no need to throw, the director will handle tSC
set pResponse=##class(Ens.StreamContainer).%New()
return pResponse.StreamSet(tResponse.Data)
Sean Connelly · Aug 12, 2022 
ClassMethod OnPage() As %Status [ ServerOnly = 1 ]
{
    
    //just the query string...
    set qs=%request.CgiEnvs("QUERY_STRING")
        
    //SOLUTION 1: $piece only
    set externalCenterCode=$p(qs,":")	
    set startDateRange=$p($p(qs,":authoredOn=le",2),":")
    set endDataRange=$p($p(qs,":authoredOn=ge",2),":")

    
    //SOLUTION 2: generic solution if params grow	
    for i=1:1:$l(qs,":") {
        set nvp=$p(qs,":",i),name=$p(nvp,"=",1),value=$p(nvp,"=",2)
        //fix the quirks
        if value="" set value="name",name="ecc"
        if name="authoredOn" set name=$e(value,1,2),value=$e(value,3,*)
        set params(name)=value
    }

    //SOLUTION 3: regex(ish) solution
    set code=$p(qs,":")
    set loc=$locate(qs,"le\d{4}-\d{2}-\d{2}")
    set start=$e(qs,loc+2,loc+11)
    set loc=$locate(qs,"ge\d{4}-\d{2}-\d{2}")
    set end=$e(qs,loc+2,loc+11)


    //some helper code to dump the variables into the CSP page
    write !,"<pre>"
    zwrite
    //use this to take a good look at the request object...
    zwrite %request
    write !,"</pre>"
    quit $$$OK
}

Here are three solutions and a couple of inline tips, including your request for regex example

I wouldn't worry too much about using $piece, its very common to use it in this way

Eduards comment above also has a fourth suggestion to use $lfs (list from string) which is also commonly used as a way of piecing out data