org.hd.d.pg2k.clApp.atHome
Class AHStandaloneMain.FakeTunnel

java.lang.Object
  org.hd.d.pg2k.clApp.atHome.AHStandaloneMain.FakeTunnel

All Implemented Interfaces:

SimpleExhibitPipelineIF, BasicVarMgrInterface, SimpleVariablePipelineIF

Enclosing class:

AHStandaloneMain

private static final class AHStandaloneMain.FakeTunnel
extends java.lang.Object
implements SimpleExhibitPipelineIF

Fake data source cobbled together to just support the actions some Scorers and their support need. Blocks all other activity, and does not have a real tunnel back to the server at all.

This fakes the fetching of thumbnails (on demand) using their normal URLs.

hostnameAndOptionalPort

private final java.lang.String hostnameAndOptionalPort

Hostname of our server to fetch thumbnails from; never null.

log

private final SimpleLoggerIF log

Logger; never null.

cacheDir

private final java.io.File cacheDir

Handle on local cache dir; null if none.

supportedExhibits

private volatile java.util.Set<java.lang.String> supportedExhibits

Immutable (atomically-replacable) current set of full exhibit names that we support; never null.

aeid

private volatile AllExhibitImmutableData aeid

Cache of AEID value; never null.

gp

private final GenProps gp

Empty GP value; never null.

_tnDownloadCount

private final java.util.concurrent.atomic.AtomicInteger _tnDownloadCount

Thumbnail fetch count; watch those calories^Wbytes.

MIN_TN_RETRY_MS

private static final int MIN_TN_RETRY_MS

Minimum wait before retrying thumbnail fetch from server, ms; strictly positive.

See Also:

Constant Field Values

_tnNotFetchBefore

private final java.util.Map<java.lang.String,java.lang.Long> _tnNotFetchBefore

Thread-safe cache for time before retry of thumbnail fetch is allowed.

_tnCache

private final java.util.Map<java.lang.String,ExhibitThumbnails> _tnCache

Thread-safe thumbnail cache, holding thumbnails for the calibration set.

tnFetchLock

private final java.lang.Object tnFetchLock

Serialise thumbnail fetches, ie limit calls back to server, on this lock.

AHStandaloneMain.FakeTunnel

AHStandaloneMain.FakeTunnel(java.lang.String hostnameAndOptionalPort,
                            SimpleLoggerIF log,
                            java.io.File cacheDir)

Construct an instance, given the hostname and optional port.

setSupportedExhibits

void setSupportedExhibits(java.util.Set<java.lang.String> s)

Set/update the current set of full exhibit names.

destroy

public void destroy()

Description copied from interface: SimpleExhibitPipelineIF

Shut down the data pipeline. Free resources having saved any persistent state and shut down any upstream components.

Specified by:

destroy in interface SimpleExhibitPipelineIF

getAllExhibitImmutableData

public AllExhibitImmutableData getAllExhibitImmutableData(long oldStamp)
                                                   throws java.io.IOException

Description copied from interface: SimpleExhibitPipelineIF

Gets set of all static exhibit data if its timestamp is not that specified. If the time specified is negative the object will be returned unconditionally.

If no exhibits are currently installed a default set with a zero timestamp is returned.

If the caller's copy appears to be up-to-date (eg the oldStamp matches that that would have been returned) null is returned.

Specified by:

getAllExhibitImmutableData in interface SimpleExhibitPipelineIF

Throws:

java.io.IOException - if the operation cannot be completed due to I/O restrictions or failure

getAllExhibitProperties

public AllExhibitProperties getAllExhibitProperties(long oldHash)
                                             throws java.io.IOException

AEP is too expensive (large, slow) to fetch and is more than we need, so forbid it.

Specified by:

getAllExhibitProperties in interface SimpleExhibitPipelineIF

Throws:

java.io.IOException - if the operation cannot be completed due to I/O restrictions or failure

getGenProps

public GenProps getGenProps(long oldStamp)
                     throws java.io.IOException

Description copied from interface: SimpleExhibitPipelineIF

Gets the general properties as a GenProps object if its timestamp is not that specified; never null for -1 argument. If the time specified is negative the object will be returned unconditionally.

If no props are currently installed/available a default set with a zero timestamp is returned.

If the caller's copy appears to be up-to-date (eg the oldStamp matches that that would have been returned) null is returned.

Specified by:

getGenProps in interface SimpleExhibitPipelineIF

Throws:

java.io.IOException - if the operation cannot be completed due to I/O restrictions or failure

getGenSecProps

public java.util.Properties getGenSecProps(long oldStamp)
                                    throws java.io.IOException

Description copied from interface: SimpleExhibitPipelineIF

Gets the generic security properties as a Properties object if its timestamp is not that specified. If the time specified is negative the object will be returned unconditionally.

If no props are currently installed/available a default set with a zero timestamp is returned.

If the caller's copy appears to be up-to-date (eg the oldStamp matches that that would have been returned) null is returned.

Specified by:

getGenSecProps in interface SimpleExhibitPipelineIF

Throws:

java.io.IOException - if the operation cannot be completed due to I/O restrictions or failure

getProperties

public java.util.Properties getProperties(SimpleExhibitPipelineIF.PropsKey key,
                                          long versionID)
                                   throws java.io.IOException

Description copied from interface: SimpleExhibitPipelineIF

Get requested Properties selected by key and versionID. Fetches a Properties set unconditionally (versionID == -1) else if the versionID presented is not current.

Specified by:

getProperties in interface SimpleExhibitPipelineIF

Parameters:

key - selector (with possible embedded sub-key) for desired properties set; never null

versionID - if -1 then map is always returned if available, else must be non-negative and null is returned if the versionID presented matches that of the current version (ie if the caller has presumably got the up-to-date version); may be a timestamp or a hash or other value, and by convention is zero only for an empty properties set

Returns:

null, or Properties map guaranteed to contain only String keys and values

Throws:

java.io.IOException

getRawFile

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

Description copied from interface: SimpleExhibitPipelineIF

Read a chunk of the raw exhibit binary into the given buffer. The call may return less than the the buffer capacity, though will block until it has read at least one byte unless at EOF or for a zero-byte request; this will be clear from the state of the buffer.

Specified by:

getRawFile in interface SimpleExhibitPipelineIF

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 may 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

getStaticAttr

public ExhibitStaticAttr getStaticAttr(java.lang.String name)
                                throws java.io.IOException

Description copied from interface: SimpleExhibitPipelineIF

Get the static attributes for a given exhibit. Returns null if the named exhibit does not exist.

Specified by:

getStaticAttr in interface SimpleExhibitPipelineIF

Throws:

java.io.IOException - if the operation cannot be completed due to I/O restrictions or failure

poll

public void poll(GenProps gp)
          throws java.io.IOException

Description copied from interface: SimpleExhibitPipelineIF

Poll periodically (of the order of seconds) to do background work. The current generic system properties are passed in...

Specified by:

poll in interface SimpleExhibitPipelineIF

Throws:

java.io.IOException - in case of difficulty, but even if a sub-ordinate call throws IOException then poll() call should continue to do as much of its remaining work as reasonably possible

syncVariables

public void syncVariables(boolean force)
                   throws java.io.IOException

Description copied from interface: SimpleVariablePipelineIF

Synchronise variables with upstream values. Pushes updated values upstream to the source, calls sync on the source if called with the "force" argument true, and then retrieves changed values from upstream.

When called with force==true, this acts like a full "memory barrier", flushing all write-cached items downstream immediately and afterwards getting the value of all upstream values with getVariables(-1), but may be expensive in terms of CPU or bandwidth, so use sparingly.

When called with force==false, this incrementally flushes outstanding writes and will then fetch all, or only new, values from upstream, so is potentally much less resource-intensive. In particular, this does not propagate the sync() upstream.

In any case, it is rarely the right thing for a casual user to vall this as it may be very expensive.

Specified by:

syncVariables in interface SimpleVariablePipelineIF

Parameters:

force - if true, this will force a full write flush, a full sync upstream, then full read with getVariables(-1), to get the effect of a full "barrier"; otherwise, in general, a more incremental and non-propagating mode is used which still does a write flush but may chose to do a partial read of "new" upstream values

Throws:

java.io.IOException - if one is received from upstream

getEventValue

public EventVariableValue getEventValue(SimpleVariableDefinition def,
                                        EventPeriod intervalSelector,
                                        boolean current)

Always return empty values.

Specified by:

getEventValue in interface BasicVarMgrInterface

Parameters:

def - event definition (must be for an event); never null

intervalSelector - never null

current - if true the current event set is returned, else the previous complete set is returned

Returns:

requested event set; never null

getEventValues

public EventVariableValue[] getEventValues(SimpleVariableDefinition def,
                                           EventPeriod intervalSelector,
                                           long intervalNumber,
                                           java.util.BitSet whichValues)

Description copied from interface: BasicVarMgrInterface

Get the specified event sets for the specified intervals; never null. This allows retrieval of zero or more event sets for the specified interval size.

Requests for more than SystemVariables.EVENT_SAMPLES_RETAINED in the past (or for the future!) cannot be satisfied and data will not be returned for them.

Usually not more than SystemVariables.EVENT_SAMPLES_RETAINED samples will be returned in response to any one request as a safety measure.

An implementation that is not an end-point may go upstream to fetch missing values and cache them to satisfy future requests. However, if unable to fetch authoritative data (quickly) then we will return null or non-authoritative data as appropriate for each slot; this does not throw IOException.

Specified by:

getEventValues in interface BasicVarMgrInterface

Parameters:

def - event definition (must be for an event); never null

intervalSelector - never null

intervalNumber - the number of the first interval for which data is potentially required; if too far in the past or future then possibly no data will be available, zero is used to select the "all" bucket

whichValues - each true bit represents a slot for which data is required, bit 0 indicating data from the slot within which firstIntervalTime is located, bit 1 the previous slot, etc; null is treated as the common case equivalent to just bit 0 set

Returns:

as many of the requested values as available, with as many of them authoritative as possible, with [0] corresponding to bit 0 in the BitSet; may contain nulls or be zero-length (or over-sized) but never null

getVariable

public SimpleVariableValue getVariable(SimpleVariableDefinition var)
                                throws java.io.IOException,
                                       java.lang.UnsupportedOperationException

Description copied from interface: BasicVarMgrInterface

Get a single variable value; returns null if no such value or wrong type. Implementations should, where possible, trim from the globalMap of returned values any apparently-stale data, so as to return only reasonably-live data to the caller.

Only the last event value for a given event variable is returned by this method.

Specified by:

getVariable in interface BasicVarMgrInterface

Parameters:

var - definition of variable to fetch; never null

Throws:

java.io.IOException - in case of I/O difficulty

java.lang.UnsupportedOperationException - if a variable is requested that we could never supply, eg a non-System-ID local variable at the client end of a tunnel

getVariables

public SimpleVariableValue[] getVariables(long changedSince)
                                   throws java.io.IOException

Description copied from interface: BasicVarMgrInterface

Get set of variable values altered on or after specified time, or get all values with -1; never null. This may be slow if there are many live variables.

Only the last event value of each event variable is returned by this method.

Specified by:

getVariables in interface BasicVarMgrInterface

Throws:

java.io.IOException - in case of I/O difficulty

setVariable

public void setVariable(SimpleVariableValue newValue)
                 throws java.io.IOException,
                        java.lang.UnsupportedOperationException

Description copied from interface: BasicVarMgrInterface

Set variable to the given value (the variable name and definition are implicit). The value set should be immediately readable with getVariable() as the "main" value of the variable even for global variables.

This is also used to send events, the last event value being the variable's value.

Specified by:

setVariable in interface BasicVarMgrInterface

Throws:

java.io.IOException - in case of I/O difficulty

java.lang.UnsupportedOperationException - if a variable is set that we could never handle, eg a non-System-ID local variable at the client end of a tunnel

setVariables

public int setVariables(SimpleVariableValue[] newValues)
                 throws java.io.IOException

Description copied from interface: BasicVarMgrInterface

Update a number of variables at once for efficiency; returns the number of variables set. Is passed a set of SimpleVariableValues and behaves as if it operates on all of them by calling setVariable() for each item in the set.

Furthermore it behaves as if the set operations are done in order, from low index to high index, unless variables are coalesced (multiple sets of the same simple variable can keep just the last value). Set operations of different variables may be re-ordered with respect to one another in order that redundancy may reduced for transmission and storage, so this implicitly allows, for example, events to be re-ordered with respect to non-event variables.

An implementation may "fail fast" on the first error/exception, or may attempt to continue and do as much as possible.

An implementation may throw an IllegalArgumentException on attempt to: set a variable with value of wrong type or incompatible definition, set a non-existent or read-only variable (or these may be ignored)

Specified by:

setVariables in interface BasicVarMgrInterface

Returns:

the number of variable values set (the length of the array); never negative, never more than the number passed in

Throws:

java.io.IOException

getThumbnails

public ExhibitThumbnails getThumbnails(java.lang.String fullName,
                                       boolean create)
                                throws java.io.IOException

Get std onlythumbnail; returns null if not currently available. Fetched only if part of the calibration set; cached too if so.

Specified by:

getThumbnails in interface SimpleExhibitPipelineIF

create - if true, and no thumbnail yet exists, try to create one if possible, else if create is false only return an existing one and return null if none is to hand

Throws:

java.io.IOException - if the operation cannot be completed due to I/O restrictions or failure