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Conference azur::mcc

Title:DECmcc user notes file. Does not replace IPMT.
Notice:Use IPMT for problems. Newsletter location in note 6187
Moderator:TAEC::BEROUD
Created:Mon Aug 21 1989
Last Modified:Wed Jun 04 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6497
Total number of notes:27359

3023.0. "Pb. MIR databuffer to smal" by HLRG02::SYSTEM (DECmcc PABX AM development) Tue May 19 1992 08:10

Hi,

I read in the SRM that the databuffer, which you use for the MCC_MIR_WRITE..() 
and MCC_MIR_READ...() routines, has a max size of 32184 bytes.

But with testing my own AM I encountered that the max size is 10180 bytes.
Is this right??
Or did I make a mistake??

Please help me ! ! ! !


/-/	Henk van Steeg
T.RTitleUserPersonal
Name
DateLines
3023.1more infoHLRG02::SYSTEMDECmcc PABX AM developmentTue May 19 1992 09:309
I forget to mention:

The returned status from MCC_MIR_WRITE_ATTR_DATA(...) is 100004.
I don't know what this status means.

Please help


/-/	Henk
3023.2TOOK::GUERTINIt fall down, go boomTue May 19 1992 11:4215
    Is this VMS or ultrix?  We had to tune the buffer sizes to save any
    chance of getting reasonable performance.  I would not expect to
    actually get 32K of buffer space.  I remember going thru the SRM
    process.  It was hotly debated whether the maximum number of bytes
    stored should be allowed in the SRM or not.  I guess we blew it. 
    (I will QAR the SRM on this.)
    
    Actually the max record size varies from implementation to
    implementation, platform to platform (because of OS restrictions as
    well as restrictions on the underlying File/Database System).  Try to
    store data as efficiently as possible.  10000 bytes is 20 blocks for
    just one record.  If you really need that much space, there may be a
    way to chain records together.
    
    -Matt.
3023.3HLRG02::SYSTEMDECmcc PABX AM developmentTue May 19 1992 11:5412
Thanks for your quick response.

It is 	VMS 5.5
	DECmcc T1.2.7
VAXstation 4000 model 60  with 40MB

Do you know a method to chain records or do I have to hack something myself ?


Regards

/-/	Henk
3023.4bothTOOK::GUERTINIt fall down, go boomTue May 19 1992 12:5017
    Assuming that the you are using the MIR routines to store private data,
    you can often use the Parititon field as a sequence number.  But, if
    you really need the partition field to store the partition (most people
    don't), you can always use the time-stamp field.  This is a little more
    work, but you get the benefit of wildcarding, if you do it right. 
    These suggestions are a bit hacky so I hesitate encouraging people to
    use them this way.  Also, using them this way may invalidate your
    warantee :-}
    
    If you are NOT ILV encoding the records you can either use a
    continuation field in record, or read-until-end.  If you ARE ILV
    encoding, then I think you need to use a read-until-end algorithm (or
    the time-stamp fields) and just concatenate the buffers together.  But
    I think there is a limit to how long the ILV encodings can get.
    
    -Matt.
    
3023.5HLRG02::SYSTEMDECmcc PABX AM developmentTue May 19 1992 13:265
Thanks a lot.

I know what to do now.

/-/	Henk