org.hd.d.pg2k.test.dev
Class SimpleCacheTest.RawDataAccessMonitor

java.lang.Object
  org.hd.d.pg2k.svrCore.datasource.SimpleExhibitPipelineFilter
      org.hd.d.pg2k.test.dev.SimpleCacheTest.RawDataAccessMonitor

All Implemented Interfaces:

SimpleExhibitPipelineIF, BasicVarMgrInterface, SimpleVariablePipelineIF

Enclosing class:

SimpleCacheTest

static final class SimpleCacheTest.RawDataAccessMonitor
extends SimpleExhibitPipelineFilter

Thread-safe monitor of data-read activity. An instance of this class can be inserted into a pipeline to record data-read activity.

This filter stage does not generally impede normal operation, but simply records the data access pattern for processing.

events

private final java.util.List<SimpleCacheTest.RawDataAccessMonitor.GetRawDataEvent> events

A List of GetRawDataEvent values in the order they occurred. A Vector is used for thread-safety.

SimpleCacheTest.RawDataAccessMonitor

SimpleCacheTest.RawDataAccessMonitor(SimpleExhibitPipelineIF upstream)

Construct instance wrapped round upstream source.

Parameters:

upstream - datasource; never null

getRawFile

public void getRawFile(java.nio.ByteBuffer buf,
                       Name.ExhibitFull exhibitName,
                       int position,
                       boolean dontCache)
                throws java.io.IOException

Read a chunk of the raw exhibit binary into the given buffer. This passes the request upstream without modification, but records it in a trace buffer before passing it upstream. The trace is taken before in case the fulfillment of the request happens to be vetoed by the data source; it is the requests that we are interested in here.

Specified by:

getRawFile in interface SimpleExhibitPipelineIF

Overrides:

getRawFile in class SimpleExhibitPipelineFilter

Parameters:

buf - the buffer into which to read the data; must be non-null, in put()able state, and with remaining capacity of at least the requested number of bytes

exhibitName - the full name of the exhibit to read from; never null and must be syntactically valid

position - position/index of first byte in exhibitFile to read; non-negative

dontCache - if true, this is a hint not to attempt to cache this or displace anything from extant caches for this data as it maqy for example be precaching or random activity; by default callers should leave this false to allow cacheing

Throws:

java.io.IOException - for requests that cannot be fulfilled because of I/O restrictions or problems, such as link failure or an upper bound on the length of a request

getEventList

public java.util.List<SimpleCacheTest.RawDataAccessMonitor.GetRawDataEvent> getEventList()

Retrieve the List of events in order; never null though possibly empty. This returns a private snapshot of the event list.