com.openxc.sources.trace

Class TraceVehicleDataSource

java.lang.Object

com.openxc.sources.BaseVehicleDataSource

com.openxc.sources.ContextualVehicleDataSource

com.openxc.sources.trace.TraceVehicleDataSource

All Implemented Interfaces:

DataPipeline.Operator, VehicleDataSource, java.lang.Runnable

public class TraceVehicleDataSource
extends ContextualVehicleDataSource
implements java.lang.Runnable

A vehicle data source that reads measurements from a pre-recorded trace file. This class is primarily for testing - a pre-recorded trace of the output from an OpenXC vehicle interface is played back line by line into the library. Everything from the VehicleService on up the chain is identical to when operating in a live vehicle. The trace file format is defined in the OpenXC message format specification: https://github.com/openxc/openxc-message-format The trace file to use is specified via the constructor as an Android-style resource URI, e.g. "resource://42", "file:///storage/traces/trace.json" or a plain file path (e.g. "/sdcard/com.openxc/trace.json" ). When using resources, the ID for the resource is accessed through the generated "R.java" file. For example: URI resource = new URI("resource://" + R.raw.trace) where the trace file is located at res/raw/trace. Regular files are the preferred way to use trace files, and are required when using the OpenXC enabler app. Android apps don't have access to each others' raw resources, so the resource method will not work in that case. The trace file is played back in a continuous loop at roughly the same speed as the original recording (at least according to the timestamps in the file). Playback will not begin until a callback is set, either via a constructor or the BaseVehicleDataSource.setCallback(SourceCallback) function.

Constructor Summary

Constructors

Constructor and Description
TraceVehicleDataSource(android.content.Context context, java.lang.String filename)
TraceVehicleDataSource(android.content.Context context, java.net.URI filename)
TraceVehicleDataSource(android.content.Context context, java.net.URI filename, boolean loop)
TraceVehicleDataSource(SourceCallback callback, android.content.Context context, java.net.URI filename) Construct a trace data source with the given context, callback and trace file resource URI.
TraceVehicleDataSource(SourceCallback callback, android.content.Context context, java.net.URI filename, boolean loop)

Method Summary

Modifier and Type	Method and Description
protected java.lang.String	getTag() Return a string suitable as a tag for logging.
boolean	isConnected() Consider the trace source "connected" if it's running and at least 1 measurement was parsed successfully from the file.
void	run() While running, continuously read from the trace file and send messages to the callback.
boolean	sameFilename(java.lang.String filename)
void	start()
void	startThread(SourceCallback userCallback, android.content.Context context)
void	stop() Stop trace file playback and the playback thread.
java.lang.String	toString()
static boolean	validatePath(java.lang.String path)

Methods inherited from class com.openxc.sources.ContextualVehicleDataSource

getContext

Methods inherited from class com.openxc.sources.BaseVehicleDataSource

connected, disconnected, getCallback, handleMessage, onPipelineActivated, onPipelineDeactivated, setCallback, waitForCallback

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TraceVehicleDataSource

public TraceVehicleDataSource(SourceCallback callback,
                              android.content.Context context,
                              java.net.URI filename)
                       throws DataSourceException

Construct a trace data source with the given context, callback and trace file resource URI. If the callback is not null, playback will begin immediately.

Parameters:

context - the Activity or Service context, used to access the raw trace file resource via Android.

callback - An object implementing the SourceCallback interface that should receive data as it is received and parsed.

filename - a raw file resource URI of the format "resource://resource_id"

Throws:

DataSourceException - if no filename is specified

TraceVehicleDataSource

public TraceVehicleDataSource(SourceCallback callback,
                              android.content.Context context,
                              java.net.URI filename,
                              boolean loop)
                       throws DataSourceException

Throws:

DataSourceException

TraceVehicleDataSource

public TraceVehicleDataSource(android.content.Context context,
                              java.net.URI filename)
                       throws DataSourceException

Throws:

DataSourceException

TraceVehicleDataSource

public TraceVehicleDataSource(android.content.Context context,
                              java.lang.String filename)
                       throws DataSourceException

Throws:

DataSourceException

TraceVehicleDataSource

public TraceVehicleDataSource(android.content.Context context,
                              java.net.URI filename,
                              boolean loop)
                       throws DataSourceException

Throws:

DataSourceException

Method Detail

isConnected

public boolean isConnected()

Consider the trace source "connected" if it's running and at least 1 measurement was parsed successfully from the file. This will catch errors e.g. if the trace is totally corrupted, but it won't give you any indication if it is partially corrupted.

Specified by:

isConnected in interface VehicleDataSource

Specified by:

isConnected in class BaseVehicleDataSource

stop

public void stop()

Stop trace file playback and the playback thread.

Specified by:

stop in interface VehicleDataSource

Overrides:

stop in class BaseVehicleDataSource

start

public void start()

startThread

public void startThread(SourceCallback userCallback,
                        android.content.Context context)

run

public void run()

While running, continuously read from the trace file and send messages to the callback. If the callback is not set, this function will exit immediately and the thread will die a quick death.

Specified by:

run in interface java.lang.Runnable

validatePath

public static boolean validatePath(java.lang.String path)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

sameFilename

public boolean sameFilename(java.lang.String filename)

getTag

protected java.lang.String getTag()

Description copied from class: BaseVehicleDataSource

Return a string suitable as a tag for logging.

Overrides:

getTag in class BaseVehicleDataSource