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/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2022 Neil C Smith.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 3 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* version 3 for more details.
*
* You should have received a copy of the GNU Lesser General Public License version 3
* along with this work; if not, see http://www.gnu.org/licenses/
*
*
* Please visit https://www.praxislive.org if you need additional information or
* have any questions.
*/
package org.praxislive.code;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.CopyOnWriteArrayList;
import org.praxislive.code.userapi.Async;
import org.praxislive.core.Call;
import org.praxislive.core.Component;
import org.praxislive.core.ComponentAddress;
import org.praxislive.core.Control;
import org.praxislive.core.ControlAddress;
import org.praxislive.core.ExecutionContext;
import org.praxislive.core.Lookup;
import org.praxislive.core.PacketRouter;
import org.praxislive.core.Port;
import org.praxislive.core.ComponentInfo;
import org.praxislive.core.Value;
import org.praxislive.core.services.Service;
import org.praxislive.core.services.Services;
import org.praxislive.core.services.LogBuilder;
import org.praxislive.core.services.LogLevel;
import org.praxislive.core.services.ServiceUnavailableException;
import org.praxislive.core.services.TaskService;
import org.praxislive.core.types.PError;
import org.praxislive.core.types.PReference;
/**
* A CodeContext wraps each {@link CodeDelegate}, managing state and the
* transition from one iteration of delegate to the next on behalf of a
* {@link CodeComponent}.
*
* @param supported delegate type
*/
public abstract class CodeContext {
private final Map controls;
private final Map ports;
private final Map refs;
private final ComponentInfo info;
private final D delegate;
private final LogBuilder log;
private final Driver driver;
private final boolean requireClock;
private final List clockListeners;
private final ResponseHandler responseHandler;
private ExecutionContext execCtxt;
private ExecutionContext.State execState = ExecutionContext.State.NEW;
private CodeComponent cmp;
private long time;
private ControlAddress responseAddress;
/**
* Create a CodeContext by processing the provided {@link CodeConnector}
* (containing CodeDelegate).
*
* @param connector code connector with delegate
*/
protected CodeContext(CodeConnector connector) {
this(connector, false);
}
/**
* Create a CodeContext by processing the provided {@link CodeConnector}
* (containing CodeDelegate). This constructor takes a boolean to force
* connecting the context to the execution clock, should the subtype always
* require clock signals.
*
* @param connector code connector with delegate
* @param requireClock true to force clock connection
*/
protected CodeContext(CodeConnector connector, boolean requireClock) {
this.driver = new Driver();
clockListeners = new CopyOnWriteArrayList<>();
// @TODO what is maximum allowed amount a root can be behind system time?
try {
connector.process();
controls = connector.extractControls();
ports = connector.extractPorts();
refs = connector.extractRefs();
info = connector.extractInfo();
delegate = connector.getDelegate();
log = new LogBuilder(LogLevel.ERROR);
this.requireClock = requireClock || connector.requiresClock();
this.responseHandler = Objects.requireNonNull((ResponseHandler) controls.get(ResponseHandler.ID));
} catch (Exception e) {
// Logger.getLogger(CodeContext.class.getName()).log(Level.FINE, "", e);
throw e;
}
}
void setComponent(CodeComponent cmp) {
this.cmp = cmp;
delegate.setContext(this);
}
void handleConfigure(CodeComponent cmp, CodeContext oldCtxt) {
configureControls(oldCtxt);
configurePorts(oldCtxt);
configureRefs(oldCtxt);
configure(cmp, oldCtxt);
}
/**
* A hook method that will be called when the CodeContext is configured on a
* component. It is called after controls, ports and refs have been
* configured. Subclasses may override this to do additional configuration.
* The default implementation does nothing.
*
* @param cmp component being attached to
* @param oldCtxt previous context, or null if there was none
*/
protected void configure(CodeComponent cmp, CodeContext oldCtxt) {
}
private void configureControls(CodeContext oldCtxt) {
Map oldControls = oldCtxt == null
? Collections.emptyMap() : oldCtxt.controls;
for (Map.Entry entry : controls.entrySet()) {
ControlDescriptor oldCD = oldControls.remove(entry.getKey());
if (oldCD != null) {
entry.getValue().attach(this, oldCD.getControl());
} else {
entry.getValue().attach(this, null);
}
}
for (ControlDescriptor oldCD : oldControls.values()) {
oldCD.dispose();
}
}
private void configurePorts(CodeContext oldCtxt) {
Map oldPorts = oldCtxt == null
? Collections.emptyMap() : oldCtxt.ports;
for (Map.Entry entry : ports.entrySet()) {
PortDescriptor oldPD = oldPorts.remove(entry.getKey());
if (oldPD != null) {
entry.getValue().attach(this, oldPD.getPort());
} else {
entry.getValue().attach(this, null);
}
}
for (PortDescriptor oldPD : oldPorts.values()) {
oldPD.getPort().disconnectAll();
oldPD.dispose();
}
}
private void configureRefs(CodeContext oldCtxt) {
Map oldRefs = oldCtxt == null
? Collections.EMPTY_MAP : oldCtxt.refs;
refs.forEach((id, ref) -> ref.attach(this, oldRefs.remove(id)));
oldRefs.forEach((id, ref) -> ref.dispose());
}
final void handleHierarchyChanged() {
hierarchyChanged();
LogLevel level = getLookup().find(LogLevel.class)
.orElse(LogLevel.ERROR);
log.setLevel(level);
ExecutionContext ctxt = cmp == null ? null : cmp.getExecutionContext();
if (execCtxt != ctxt) {
if (execCtxt != null) {
execCtxt.removeStateListener(driver);
execCtxt.removeClockListener(driver);
}
execCtxt = ctxt;
responseAddress = null;
if (ctxt != null) {
responseAddress = ControlAddress.of(cmp.getAddress(), ResponseHandler.ID);
ctxt.addStateListener(driver);
if (requireClock) {
ctxt.addClockListener(driver);
}
handleStateChanged(ctxt, false);
}
}
}
/**
* Called when the hierarchy changes, which might be because the component
* hierarchy has changed (see {@link Component#hierarchyChanged()}), the
* context has been added or is being removed from the component, or for any
* other reason that cached information should be invalidated (eg. anything
* retrieved from the lookup). Subclasses may override this to handle such
* events / invalidate lookup results. The default implementation does
* nothing.
*/
protected void hierarchyChanged() {
}
final void handleStateChanged(ExecutionContext source, boolean full) {
if (execState == source.getState()) {
return;
}
if (source.getState() == ExecutionContext.State.IDLE) {
stopping(source, full);
}
reset(full);
update(source.getTime());
execState = source.getState();
if (execState == ExecutionContext.State.ACTIVE) {
starting(source, full);
}
flush();
}
/**
* Hook called when the execution context is started (moves to state
* {@link ExecutionContext.State#ACTIVE}) or the context is added to a
* component within an active execution context. Full start will be true in
* the former case when the execution context itself is changing state.
*
* This method may be overridden in subclasses. The default implementation
* delegates to {@link #starting(org.praxislive.core.ExecutionContext)}.
*
* @param source execution context
* @param fullStart whether the context itself is transitioning state
*/
protected void starting(ExecutionContext source, boolean fullStart) {
starting(source);
}
/**
* Hook called when the execution context is started (moves to state
* {@link ExecutionContext.State#ACTIVE}) or the context is added to a
* component within an active execution context.
*
* @param source execution context
*/
protected void starting(ExecutionContext source) {
}
/**
* Hook called when the execution context is stopped (moves away from state
* {@link ExecutionContext.State#ACTIVE}) or the context is removed from a
* component within an active execution context. Full stop will be true in
* the former case when the execution context itself is changing state.
*
* This method may be overridden in subclasses. The default implementation
* delegates to {@link #stopping(org.praxislive.core.ExecutionContext)}.
*
* @param source execution context
* @param fullStop whether the context itself is transitioning state
*/
protected void stopping(ExecutionContext source, boolean fullStop) {
stopping(source);
}
/**
* Hook called when the execution context is stopped (moves away from state
* {@link ExecutionContext.State#ACTIVE}) or the context is removed from a
* component within an active execution context.
*
* @param source execution context
*/
protected void stopping(ExecutionContext source) {
}
final void handleTick(ExecutionContext source) {
update(source.getTime());
tick(source);
flush();
}
/**
* Hook called by the clock listener on the execution context. The default
* implementation does nothing.
*
* @param source execution context
*/
protected void tick(ExecutionContext source) {
}
/**
* Reset all control, port and reference descriptors. A full reset generally
* happens on execution context state changes as opposed to code change
* transitions. Descriptors may handle this differently - eg. clear injected
* values or dispose references on full.
*
* @param full whether reset is full (eg. execution state change)
*/
protected final void reset(boolean full) {
controls.values().forEach(cd -> cd.reset(full));
ports.values().forEach(pd -> pd.reset(full));
refs.values().forEach(rd -> rd.reset(full));
}
final void handleDispose() {
cmp = null;
handleHierarchyChanged();
refs.values().forEach(ReferenceDescriptor::dispose);
refs.clear();
controls.values().forEach(ControlDescriptor::dispose);
controls.clear();
ports.values().forEach(PortDescriptor::dispose);
ports.clear();
dispose();
}
/**
* Hook called during disposal of code context. The default implementation
* does nothing.
*/
protected void dispose() {
}
/**
* Get the code component this code context is attached to, if there is one.
*
* @return code component, or null
*/
public CodeComponent getComponent() {
return cmp;
}
/**
* Get the delegate this context wraps.
*
* @return delegate
*/
public D getDelegate() {
return delegate;
}
/**
* Get the control to handle the specified ID, or null if there isn't one.
*
* @param id control ID
* @return control or null
*/
protected Control getControl(String id) {
ControlDescriptor cd = controls.get(id);
return cd == null ? null : cd.getControl();
}
/**
* Get the control descriptor for the specified ID, or null if there isn't
* one.
*
* @param id control ID
* @return control descriptor or null
*/
protected ControlDescriptor getControlDescriptor(String id) {
return controls.get(id);
}
/**
* Get all the available control IDs.
*
* @return control IDs
*/
@Deprecated
protected String[] getControlIDs() {
Set keySet = controls.keySet();
return keySet.toArray(new String[keySet.size()]);
}
/**
* Get the port with the specified ID, or null if there isn't one.
*
* @param id port ID
* @return port or null
*/
protected Port getPort(String id) {
PortDescriptor pd = ports.get(id);
return pd == null ? null : pd.getPort();
}
/**
* Get the port descriptor for the specified ID, or null if there isn't one.
*
* @param id port ID
* @return port descriptor or null
*/
protected PortDescriptor getPortDescriptor(String id) {
return ports.get(id);
}
/**
* Get the available port IDs.
*
* @return port IDs
*/
@Deprecated
protected String[] getPortIDs() {
Set keySet = ports.keySet();
return keySet.toArray(new String[keySet.size()]);
}
/**
* Get component info.
*
* @return component info
*/
protected ComponentInfo getInfo() {
return info;
}
/**
* Find the address of the passed in control, or null if it does not have
* one.
*
* @param control control to find address for
* @return control address or null
*/
protected ControlAddress getAddress(Control control) {
ComponentAddress ad = cmp == null ? null : cmp.getAddress();
if (ad != null) {
for (Map.Entry ce : controls.entrySet()) {
if (ce.getValue().getControl() == control) {
return ControlAddress.of(ad, ce.getKey());
}
}
}
return null;
}
/**
* Get lookup.
*
* @return lookup
*/
public Lookup getLookup() {
return cmp == null ? Lookup.EMPTY : cmp.getLookup();
}
/**
* Locate the provided service type, if available.
*
* @param type service to lookup
* @return optional service address
*/
public Optional locateService(Class type) {
return getLookup().find(Services.class).flatMap(s -> s.locate(type));
}
/**
* Get current time in nanoseconds.
*
* @return time in nanoseconds
*/
public long getTime() {
return time;
}
/**
* Add a clock listener. Resources used inside code delegates should add a
* clock listener rather than listen directly on the execution context.
*
* @param listener clock listener
*/
public void addClockListener(ClockListener listener) {
clockListeners.add(Objects.requireNonNull(listener));
}
/**
* Remove a clock listener.
*
* @param listener to remove
*/
public void removeClockListener(ClockListener listener) {
clockListeners.remove(listener);
}
/**
* Get the execution context, or null if not attached.
*
* @return execution context, or null
*/
protected ExecutionContext getExecutionContext() {
return cmp == null ? null : cmp.getExecutionContext();
}
/**
* Check whether the CodeContext is running inside an ExecutionContext with
* active state. If the execution context is active, but a transition to
* active has not yet been handled in this code context, the state
* transition will be triggered.
*
* @return true if active
*/
protected boolean checkActive() {
if (execState == ExecutionContext.State.ACTIVE) {
return true;
}
if (execCtxt != null) {
if (execCtxt.getState() == ExecutionContext.State.ACTIVE) {
var parent = getComponent().getParent();
if (parent instanceof CodeComponent) {
((CodeComponent) parent).getCodeContext().checkActive();
}
handleStateChanged(execCtxt, true);
return execState == ExecutionContext.State.ACTIVE;
}
}
return false;
}
/**
* Update the time in this context to the specified time. A value the same
* or behind the current value will be ignored. This method will call all
* clock listeners.
*
* @param time updated time
*/
protected void update(long time) {
if (time - this.time > 0) {
this.time = time;
clockListeners.forEach(ClockListener::tick);
}
}
/**
* Invoke the provided task, if the context is active, and after updating
* the clock to the specified time (if later). Any exception will be caught
* and logged, and the context will be flushed.
*
* @param time new clock time
* @param task runnable task to execute
*/
public void invoke(long time, Runnable task) {
if (checkActive()) {
update(time);
try {
task.run();
} catch (Exception ex) {
log.log(LogLevel.ERROR, ex);
}
flush();
}
}
/**
* Invoke the provided task and return the result, if the context is active,
* and after updating the clock to the specified time (if later). Any
* exception will be logged and rethrown, and the context flushed. Throws an
* {@link IllegalStateException} if {@link #checkActive()} returns
* false.
*
* @param the result type of method call
* @param time new clock time
* @param task runnable task to execute
* @return result
* @throws Exception if unable to compute a result
*/
public V invokeCallable(long time, Callable task) throws Exception {
if (checkActive()) {
update(time);
try {
return task.call();
} catch (Exception ex) {
log.log(LogLevel.ERROR, ex);
throw ex;
} finally {
flush();
}
} else {
throw new IllegalStateException("Component not active");
}
}
void invoke(long time, Method method, Object... params) {
if (checkActive()) {
update(time);
try {
method.invoke(getDelegate(), params);
} catch (Exception ex) {
if (ex instanceof InvocationTargetException) {
Throwable t = ex.getCause();
ex = t instanceof Exception ? (Exception) t : ex;
}
StringBuilder sb = new StringBuilder("Exception thrown from ");
sb.append(method.getName());
sb.append('(');
Class[] types = method.getParameterTypes();
for (int i = 0; i < types.length; i++) {
sb.append(types[i].getSimpleName());
if (i < (types.length - 1)) {
sb.append(',');
}
}
sb.append(')');
log.log(LogLevel.ERROR, ex, sb.toString());
}
flush();
}
}
/**
* Flush the code context. By default this message checks for pending log
* messages and delivers to the log.
*/
protected void flush() {
if (!log.isEmpty()) {
log(log.toList());
log.clear();
}
}
/**
* Get the log builder for writing log messages.
*
* @return log builder
*/
public LogBuilder getLog() {
return log;
}
/**
* Get the active log level.
*
* @return active log level
*/
protected LogLevel getLogLevel() {
return log.getLevel();
}
/**
* Process and send messages from an external log builder.
*
* @param log external log builder
*/
protected void log(LogBuilder log) {
if (log.isEmpty()) {
return;
}
log(log.toList());
}
private void log(List args) {
PacketRouter router = cmp.getPacketRouter();
ControlAddress to = cmp.getLogToAddress();
ControlAddress from = responseAddress;
if (router == null || to == null) {
return;
}
router.route(Call.createQuiet(to, from, time, args));
}
final void tell(ControlAddress destination, Value value) {
Call call = Call.createQuiet(destination, responseAddress, getTime(), value);
getComponent().getPacketRouter().route(call);
}
final void tellIn(double seconds, ControlAddress destination, Value value) {
long timeCode = getTime() + ((long) (seconds * 1_000_000_000));
Call call = Call.createQuiet(destination, responseAddress, timeCode, value);
getComponent().getPacketRouter().route(call);
}
final Async ask(ControlAddress destination, List args) {
Call call = Call.create(destination, responseAddress, time, args);
getComponent().getPacketRouter().route(call);
Async async = new Async<>();
responseHandler.register(call, async);
return async;
}
final Async async(T input, Async.Task task) {
Async async = new Async<>();
try {
ControlAddress to = locateService(TaskService.class)
.map(c -> ControlAddress.of(c, TaskService.SUBMIT))
.orElseThrow(ServiceUnavailableException::new);
TaskService.Task wrapper = () -> PReference.of(task.execute(input));
Call call = Call.create(to, responseAddress, time, PReference.of(wrapper));
getComponent().getPacketRouter().route(call);
responseHandler.register(call, async, c -> {
@SuppressWarnings("unchecked")
R result = (R) PReference.from(c.args().get(0))
.flatMap(ref -> ref.as(Object.class))
.orElseThrow(IllegalStateException::new);
return result;
});
} catch (Exception ex) {
async.fail(PError.of(ex));
}
return async;
}
/**
* Listener for responding to time changes inside the context.
*/
public static interface ClockListener {
/**
* Time has changed.
*/
public void tick();
}
private class Driver implements ExecutionContext.StateListener,
ExecutionContext.ClockListener {
@Override
public void stateChanged(ExecutionContext source) {
handleStateChanged(source, true);
}
@Override
public void tick(ExecutionContext source) {
handleTick(source);
}
}
}