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Re: Piggypack Encoding/Decoding on RandomAccessFile

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Jan Burse wrote:
> Thank you for pointing to this API. Wasn't aware.
> I just had a look at the API, and also found:
> 
>      public static Reader newReader(ReadableByteChannel ch,
>                 CharsetDecoder dec,
>                 int minBufferCap)
> 
> So via the minBufferCap parameter also problems of
> overreadinging the underlying raf can be solved to
> some extend, if this is a problem.

This has been a very interesting question and ensuing thread.  I've seen this sort of multiple interaction (conflict) of resource clients a couple of times but most of those cases were unintentional and considered bugs.

One lesson is that such situations are always fraught with peril.

Which is why they pay us the big bucks.  Fraught with peril is the programmer's bread and butter.  But you can't be careless, and the questions addressed in this conversation are key.

Inevitably I wonder if the functional need can be served at a different level of the architecture.  Here's the syllogism:

The synchronization between resource clients, in this case a random access mechanism and a stream mechanism attached to the same file descriptor, will require a unified view that they share, otherwise completely independent views with no interaction between them whatsoever.  

The questions here address how the problem would be solved in breadth at the resource-access level.  The baseline model is two concurrent clients with shared state.

What about a solution in depth with a serial model?

'DataInput' and 'DataOutput' make good first responders to mixed-format binary files. That's why 'RandomAccessFile' implements them.  They're intended for the sort of low-level operations with manual bookkeeping for data location as discussed.  They are the clear choice for direct access to the resource.

If you need sequential stream access to all or part of that data, have sequential clients work with scraps piped through the lower-lying direct access instances rather than fight over the same prey.

-- 
Lew

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Thread

Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-03 19:18 +0100
  Re: Piggypack Encoding/Decoding on RandomAccessFile Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-11-03 14:32 -0500
    Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-03 20:50 +0100
      Re: Piggypack Encoding/Decoding on RandomAccessFile markspace <-@.> - 2011-11-03 13:52 -0700
        Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-03 23:13 +0100
        Re: Piggypack Encoding/Decoding on RandomAccessFile Knute Johnson <nospam@knutejohnson.com> - 2011-11-03 16:17 -0700
      Re: Piggypack Encoding/Decoding on RandomAccessFile Lew <lewbloch@gmail.com> - 2011-11-03 13:58 -0700
      Re: Piggypack Encoding/Decoding on RandomAccessFile Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-03 20:40 -0400
        Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-04 02:28 +0100
          Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-04 03:06 +0100
            Re: Piggypack Encoding/Decoding on RandomAccessFile Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-04 08:05 -0400
              Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-04 16:12 +0100
        Re: Piggypack Encoding/Decoding on RandomAccessFile rossum <rossum48@coldmail.com> - 2011-11-04 16:54 +0000
  Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-03 23:24 +0100
  Re: Piggypack Encoding/Decoding on RandomAccessFile Arne Vajhøj <arne@vajhoej.dk> - 2011-11-03 20:14 -0400
  Re: Piggypack Encoding/Decoding on RandomAccessFile Roedy Green <see_website@mindprod.com.invalid> - 2011-11-03 21:56 -0700
    [OT] Conspiracy theories are BS (Was: Piggypack Encoding/Decoding on RandomAccessFile) Lew <lewbloch@gmail.com> - 2011-11-04 10:50 -0700
      Re: [OT] Conspiracy theories are BS (Was: Piggypack Encoding/Decoding on RandomAccessFile) Arne Vajhøj <arne@vajhoej.dk> - 2011-11-04 21:07 -0400
      Re: [OT] Conspiracy theories are BS (Was: Piggypack Encoding/Decoding on RandomAccessFile) Roedy Green <see_website@mindprod.com.invalid> - 2011-11-05 20:21 -0700
      Re: [OT] Conspiracy theories are BS (Was: Piggypack Encoding/Decoding on RandomAccessFile) Roedy Green <see_website@mindprod.com.invalid> - 2011-11-05 20:24 -0700
        Re: [OT] Conspiracy theories are BS (Was: Piggypack Encoding/Decoding on RandomAccessFile) Jan Burse <janburse@fastmail.fm> - 2011-11-06 10:36 +0100
      Re: [OT] Conspiracy theories are BS (Was: Piggypack Encoding/Decoding on RandomAccessFile) Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-11-06 14:16 -0600
  Re: Piggypack Encoding/Decoding on RandomAccessFile Stanimir Stamenkov <s7an10@netscape.net> - 2011-11-05 16:51 +0200
    Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-05 16:27 +0100
      Re: Piggypack Encoding/Decoding on RandomAccessFile Lew <lewbloch@gmail.com> - 2011-11-05 10:03 -0700
        Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-05 19:37 +0100
          Re: Piggypack Encoding/Decoding on RandomAccessFile Lew <lewbloch@gmail.com> - 2011-11-05 13:25 -0700
        Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-05 19:47 +0100
        Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-05 19:56 +0100
          Re: Piggypack Encoding/Decoding on RandomAccessFile Lew <lewbloch@gmail.com> - 2011-11-05 13:29 -0700
            Re: Piggypack Encoding/Decoding on RandomAccessFile Jan Burse <janburse@fastmail.fm> - 2011-11-06 10:42 +0100

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