/*******************************************************************************
- * Copyright (c) 2012 Ericsson
+ * Copyright (c) 2012, 2013 Ericsson
* Copyright (c) 2010, 2011 École Polytechnique de Montréal
* Copyright (c) 2010, 2011 Alexandre Montplaisir <alexandre.montplaisir@gmail.com>
- *
+ *
* All rights reserved. This program and the accompanying materials are
* made available under the terms of the Eclipse Public License v1.0 which
* accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
- *
+ *
*******************************************************************************/
package org.eclipse.linuxtools.internal.tmf.core.statesystem;
+import java.io.File;
+import java.io.IOException;
import java.io.PrintWriter;
+import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
-
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.linuxtools.internal.tmf.core.Activator;
+import org.eclipse.linuxtools.internal.tmf.core.statesystem.backends.IStateHistoryBackend;
import org.eclipse.linuxtools.tmf.core.exceptions.AttributeNotFoundException;
+import org.eclipse.linuxtools.tmf.core.exceptions.StateSystemDisposedException;
import org.eclipse.linuxtools.tmf.core.exceptions.StateValueTypeException;
import org.eclipse.linuxtools.tmf.core.exceptions.TimeRangeException;
+import org.eclipse.linuxtools.tmf.core.interval.ITmfStateInterval;
+import org.eclipse.linuxtools.tmf.core.interval.TmfStateInterval;
+import org.eclipse.linuxtools.tmf.core.statesystem.ITmfStateSystemBuilder;
import org.eclipse.linuxtools.tmf.core.statevalue.ITmfStateValue;
+import org.eclipse.linuxtools.tmf.core.statevalue.ITmfStateValue.Type;
import org.eclipse.linuxtools.tmf.core.statevalue.TmfStateValue;
/**
- * This is the base class for the StateHistorySystem. It contains all the
- * current-state-updating methods.
- *
- * It's not abstract, as it can be used by itself: in this case, no History tree
- * will be built underneath (no information will be saved to disk) and it will
- * only be able to respond to queries to the current, latest time.
- *
- * (See IStateSystemQuerier and IStateSystemBuilder for the Javadoc.)
- *
+ * This is the core class of the Generic State System. It contains all the
+ * methods to build and query a state history. It's exposed externally through
+ * the IStateSystemQuerier and IStateSystemBuilder interfaces, depending if the
+ * user needs read-only access or read-write access.
+ *
+ * When building, DON'T FORGET to call .closeHistory() when you are done
+ * inserting intervals, or the storage backend will have no way of knowing it
+ * can close and write itself to disk, and its thread will keep running.
+ *
* @author alexmont
- *
+ *
*/
-public class StateSystem {
+public class StateSystem implements ITmfStateSystemBuilder {
/* References to the inner structures */
- protected AttributeTree attributeTree;
- protected TransientState transState;
+ private final AttributeTree attributeTree;
+ private final TransientState transState;
+ private final IStateHistoryBackend backend;
+
+ /* Latch tracking if the state history is done building or not */
+ private final CountDownLatch finishedLatch = new CountDownLatch(1);
+
+ private boolean buildCancelled = false;
+ private boolean isDisposed = false;
+
+ /**
+ * New-file constructor. For when you build a state system with a new file,
+ * or if the back-end does not require a file on disk.
+ *
+ * @param backend
+ * Back-end plugin to use
+ */
+ public StateSystem(@NonNull IStateHistoryBackend backend) {
+ this.backend = backend;
+ this.transState = new TransientState(backend);
+ this.attributeTree = new AttributeTree(this);
+ }
/**
- * Constructor. No configuration needed!
+ * General constructor
+ *
+ * @param backend
+ * The "state history storage" back-end to use.
+ * @param newFile
+ * Put true if this is a new history started from scratch. It is
+ * used to tell the state system where to get its attribute tree.
+ * @throws IOException
+ * If there was a problem creating the new history file
*/
- public StateSystem() {
- attributeTree = new AttributeTree(this);
+ public StateSystem(@NonNull IStateHistoryBackend backend, boolean newFile)
+ throws IOException {
+ this.backend = backend;
+ this.transState = new TransientState(backend);
- /* This will tell the builder to discard the intervals */
- transState = new TransientState(null);
+ if (newFile) {
+ attributeTree = new AttributeTree(this);
+ } else {
+ /* We're opening an existing file */
+ this.attributeTree = new AttributeTree(this, backend.supplyAttributeTreeReader());
+ transState.setInactive();
+ finishedLatch.countDown(); /* The history is already built */
+ }
}
- public int getNbAttributes() {
- return attributeTree.getNbAttributes();
+ @Override
+ public boolean isCancelled() {
+ return buildCancelled;
+ }
+
+ @Override
+ public void waitUntilBuilt() {
+ try {
+ finishedLatch.await();
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ }
+
+ @Override
+ public boolean waitUntilBuilt(long timeout) {
+ boolean ret = false;
+ try {
+ ret = finishedLatch.await(timeout, TimeUnit.MILLISECONDS);
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ return ret;
+ }
+
+ @Override
+ public synchronized void dispose() {
+ isDisposed = true;
+ if (transState.isActive()) {
+ transState.setInactive();
+ buildCancelled = true;
+ }
+ backend.dispose();
+ }
+
+ //--------------------------------------------------------------------------
+ // General methods related to the attribute tree
+ //--------------------------------------------------------------------------
+
+ /**
+ * Get the attribute tree associated with this state system. This should be
+ * the only way of accessing it (and if subclasses want to point to a
+ * different attribute tree than their own, they should only need to
+ * override this).
+ *
+ * @return The attribute tree
+ */
+ public AttributeTree getAttributeTree() {
+ return attributeTree;
}
/**
- * @name Quark-retrieving methods
+ * Method used by the attribute tree when creating new attributes, to keep
+ * the attribute count in the transient state in sync.
*/
+ protected void addEmptyAttribute() {
+ transState.addEmptyEntry();
+ }
+
+ @Override
+ public int getNbAttributes() {
+ return getAttributeTree().getNbAttributes();
+ }
+
+ @Override
+ public String getAttributeName(int attributeQuark) {
+ return getAttributeTree().getAttributeName(attributeQuark);
+ }
+ @Override
+ public String getFullAttributePath(int attributeQuark) {
+ return getAttributeTree().getFullAttributeName(attributeQuark);
+ }
+
+ //--------------------------------------------------------------------------
+ // Methods related to the storage backend
+ //--------------------------------------------------------------------------
+
+ @Override
+ public long getStartTime() {
+ return backend.getStartTime();
+ }
+
+ @Override
+ public long getCurrentEndTime() {
+ return backend.getEndTime();
+ }
+
+ @Override
+ public void closeHistory(long endTime) throws TimeRangeException {
+ File attributeTreeFile;
+ long attributeTreeFilePos;
+ long realEndTime = endTime;
+
+ if (realEndTime < backend.getEndTime()) {
+ /*
+ * This can happen (empty nodes pushing the border further, etc.)
+ * but shouldn't be too big of a deal.
+ */
+ realEndTime = backend.getEndTime();
+ }
+ transState.closeTransientState(realEndTime);
+ backend.finishedBuilding(realEndTime);
+
+ attributeTreeFile = backend.supplyAttributeTreeWriterFile();
+ attributeTreeFilePos = backend.supplyAttributeTreeWriterFilePosition();
+ if (attributeTreeFile != null) {
+ /*
+ * If null was returned, we simply won't save the attribute tree,
+ * too bad!
+ */
+ getAttributeTree().writeSelf(attributeTreeFile, attributeTreeFilePos);
+ }
+ finishedLatch.countDown(); /* Mark the history as finished building */
+ }
+
+ //--------------------------------------------------------------------------
+ // Quark-retrieving methods
+ //--------------------------------------------------------------------------
+
+ @Override
public int getQuarkAbsolute(String... attribute)
throws AttributeNotFoundException {
- return attributeTree.getQuarkDontAdd(-1, attribute);
+ return getAttributeTree().getQuarkDontAdd(-1, attribute);
}
+ @Override
public int getQuarkAbsoluteAndAdd(String... attribute) {
- return attributeTree.getQuarkAndAdd(-1, attribute);
+ return getAttributeTree().getQuarkAndAdd(-1, attribute);
}
+ @Override
public int getQuarkRelative(int startingNodeQuark, String... subPath)
throws AttributeNotFoundException {
- return attributeTree.getQuarkDontAdd(startingNodeQuark, subPath);
+ return getAttributeTree().getQuarkDontAdd(startingNodeQuark, subPath);
}
+ @Override
public int getQuarkRelativeAndAdd(int startingNodeQuark, String... subPath) {
- return attributeTree.getQuarkAndAdd(startingNodeQuark, subPath);
+ return getAttributeTree().getQuarkAndAdd(startingNodeQuark, subPath);
}
+ @Override
public List<Integer> getSubAttributes(int quark, boolean recursive)
throws AttributeNotFoundException {
- return attributeTree.getSubAttributes(quark, recursive);
+ return getAttributeTree().getSubAttributes(quark, recursive);
}
+ @Override
public List<Integer> getQuarks(String... pattern) {
- List<Integer> quarks = new LinkedList<Integer>();
- List<String> prefix = new LinkedList<String>();
- List<String> suffix = new LinkedList<String>();
+ List<Integer> quarks = new LinkedList<>();
+ List<String> prefix = new LinkedList<>();
+ List<String> suffix = new LinkedList<>();
boolean split = false;
String[] prefixStr;
String[] suffixStr;
* If there was no wildcard, we'll only return the one matching
* attribute, if there is one.
*/
- if (split == false) {
+ if (!split) {
int quark;
try {
quark = getQuarkAbsolute(prefixStr);
} else {
startingAttribute = getQuarkAbsolute(prefixStr);
}
- directChildren = attributeTree.getSubAttributes(startingAttribute,
- false);
+ directChildren = getSubAttributes(startingAttribute, false);
} catch (AttributeNotFoundException e) {
/* That attribute path did not exist, return the empty array */
return quarks;
return quarks;
}
- /**
- * @name External methods related to insertions in the history -
- */
+ //--------------------------------------------------------------------------
+ // Methods related to insertions in the history
+ //--------------------------------------------------------------------------
+ @Override
public void modifyAttribute(long t, ITmfStateValue value, int attributeQuark)
throws TimeRangeException, AttributeNotFoundException,
StateValueTypeException {
transState.processStateChange(t, value, attributeQuark);
}
+ @Override
public void incrementAttribute(long t, int attributeQuark)
throws StateValueTypeException, TimeRangeException,
AttributeNotFoundException {
- int prevValue = queryOngoingState(attributeQuark).unboxInt();
- /* prevValue should be == 0 if the attribute wasn't existing before */
+ ITmfStateValue stateValue = queryOngoingState(attributeQuark);
+ int prevValue = 0;
+ /* if the attribute was previously null, start counting at 0 */
+ if (!stateValue.isNull()) {
+ prevValue = stateValue.unboxInt();
+ }
modifyAttribute(t, TmfStateValue.newValueInt(prevValue + 1),
attributeQuark);
}
+ @Override
public void pushAttribute(long t, ITmfStateValue value, int attributeQuark)
throws TimeRangeException, AttributeNotFoundException,
StateValueTypeException {
- Integer stackDepth = 0;
+ Integer stackDepth;
int subAttributeQuark;
ITmfStateValue previousSV = transState.getOngoingStateValue(attributeQuark);
* If the StateValue was null, this means this is the first time we
* use this attribute. Leave stackDepth at 0.
*/
- } else if (previousSV.getType() == 0) {
+ stackDepth = 0;
+ } else if (previousSV.getType() == Type.INTEGER) {
/* Previous value was an integer, all is good, use it */
stackDepth = previousSV.unboxInt();
} else {
throw new StateValueTypeException();
}
- if (stackDepth >= 10) {
+ if (stackDepth >= 100000) {
/*
- * Limit stackDepth to 10, to avoid having Attribute Trees grow out
+ * Limit stackDepth to 100000, to avoid having Attribute Trees grow out
* of control due to buggy insertions
*/
String message = "Stack limit reached, not pushing"; //$NON-NLS-1$
}
stackDepth++;
- subAttributeQuark = getQuarkRelativeAndAdd(attributeQuark,
- stackDepth.toString());
+ subAttributeQuark = getQuarkRelativeAndAdd(attributeQuark, stackDepth.toString());
- modifyAttribute(t, TmfStateValue.newValueInt(stackDepth),
- attributeQuark);
+ modifyAttribute(t, TmfStateValue.newValueInt(stackDepth), attributeQuark);
modifyAttribute(t, value, subAttributeQuark);
}
- public void popAttribute(long t, int attributeQuark)
+ @Override
+ public ITmfStateValue popAttribute(long t, int attributeQuark)
throws AttributeNotFoundException, TimeRangeException,
StateValueTypeException {
- Integer stackDepth;
- int subAttributeQuark;
- ITmfStateValue previousSV = transState.getOngoingStateValue(attributeQuark);
+ /* These are the state values of the stack-attribute itself */
+ ITmfStateValue previousSV = queryOngoingState(attributeQuark);
if (previousSV.isNull()) {
- /* Same as if stackDepth == 0, see below */
- return;
- }
- if (previousSV.getType() != 0) {
- /*
- * The existing value was a string, this doesn't look like a valid
- * stack attribute.
- */
- throw new StateValueTypeException();
- }
-
- stackDepth = previousSV.unboxInt();
-
- if (stackDepth == 0) {
/*
* Trying to pop an empty stack. This often happens at the start of
* traces, for example when we see a syscall_exit, without having
* the corresponding syscall_entry in the trace. Just ignore
* silently.
*/
- return;
+ return null;
+ }
+ if (previousSV.getType() != Type.INTEGER) {
+ /*
+ * The existing value was not an integer (which is expected for
+ * stack tops), this doesn't look like a valid stack attribute.
+ */
+ throw new StateValueTypeException();
}
- if (stackDepth < 0) {
+ Integer stackDepth = previousSV.unboxInt();
+
+ if (stackDepth <= 0) {
/* This on the other hand should not happen... */
- String message = "A top-level stack attribute " + //$NON-NLS-1$
- "cannot have a negative integer value."; //$NON-NLS-1$
+ String message = "A top-level stack attribute cannot " + //$NON-NLS-1$
+ "have a value of 0 or less."; //$NON-NLS-1$
throw new StateValueTypeException(message);
}
- /* The attribute should already exist... */
- subAttributeQuark = getQuarkRelative(attributeQuark,
- stackDepth.toString());
+ /* The attribute should already exist at this point */
+ int subAttributeQuark = getQuarkRelative(attributeQuark, stackDepth.toString());
+ ITmfStateValue poppedValue = queryOngoingState(subAttributeQuark);
- stackDepth--;
- modifyAttribute(t, TmfStateValue.newValueInt(stackDepth),
- attributeQuark);
+ /* Update the state value of the stack-attribute */
+ ITmfStateValue nextSV;
+ if (--stackDepth == 0 ) {
+ /* Store a null state value */
+ nextSV = TmfStateValue.nullValue();
+ } else {
+ nextSV = TmfStateValue.newValueInt(stackDepth);
+ }
+ modifyAttribute(t, nextSV, attributeQuark);
+
+ /* Delete the sub-attribute that contained the user's state value */
removeAttribute(t, subAttributeQuark);
+
+ return poppedValue;
}
+ @Override
public void removeAttribute(long t, int attributeQuark)
throws TimeRangeException, AttributeNotFoundException {
assert (attributeQuark >= 0);
* "Nullify our children first, recursively. We pass 'false' because we
* handle the recursion ourselves.
*/
- childAttributes = attributeTree.getSubAttributes(attributeQuark, false);
+ childAttributes = getSubAttributes(attributeQuark, false);
for (Integer childNodeQuark : childAttributes) {
assert (attributeQuark != childNodeQuark);
removeAttribute(t, childNodeQuark);
* Will not happen since we're inserting null values only, but poor
* compiler has no way of knowing this...
*/
- e.printStackTrace();
+ throw new IllegalStateException(e);
}
}
- /**
- * @name "Current" query/update methods -
- */
+ //--------------------------------------------------------------------------
+ // "Current" query/update methods
+ //--------------------------------------------------------------------------
+ @Override
public ITmfStateValue queryOngoingState(int attributeQuark)
throws AttributeNotFoundException {
return transState.getOngoingStateValue(attributeQuark);
}
+ @Override
+ public long getOngoingStartTime(int attribute)
+ throws AttributeNotFoundException {
+ return transState.getOngoingStartTime(attribute);
+ }
+
+ @Override
public void updateOngoingState(ITmfStateValue newValue, int attributeQuark)
throws AttributeNotFoundException {
transState.changeOngoingStateValue(attributeQuark, newValue);
}
- public String getAttributeName(int attributeQuark) {
- return attributeTree.getAttributeName(attributeQuark);
+ /**
+ * Modify the whole "ongoing state" (state values + start times). This can
+ * be used when "seeking" a state system to a different point in the trace
+ * (and restoring the known stateInfo at this location). Use with care!
+ *
+ * @param newStateIntervals
+ * The new List of state values to use as ongoing state info
+ */
+ protected void replaceOngoingState(List<ITmfStateInterval> newStateIntervals) {
+ transState.replaceOngoingState(newStateIntervals);
+ }
+
+ //--------------------------------------------------------------------------
+ // Regular query methods (sent to the back-end)
+ //--------------------------------------------------------------------------
+
+ @Override
+ public synchronized List<ITmfStateInterval> queryFullState(long t)
+ throws TimeRangeException, StateSystemDisposedException {
+ if (isDisposed) {
+ throw new StateSystemDisposedException();
+ }
+
+ List<ITmfStateInterval> stateInfo = new ArrayList<>(getNbAttributes());
+
+ /* Bring the size of the array to the current number of attributes */
+ for (int i = 0; i < getNbAttributes(); i++) {
+ stateInfo.add(null);
+ }
+
+ /* Query the storage backend */
+ backend.doQuery(stateInfo, t);
+
+ /*
+ * If we are currently building the history, also query the "ongoing"
+ * states for stuff that might not yet be written to the history.
+ */
+ if (transState.isActive()) {
+ transState.doQuery(stateInfo, t);
+ }
+
+ /*
+ * We should have previously inserted an interval for every attribute.
+ * If we do happen do see a 'null' object here, just replace it with a a
+ * dummy internal with a null value, to avoid NPE's further up.
+ */
+ for (int i = 0; i < stateInfo.size(); i++) {
+ if (stateInfo.get(i) == null) {
+ stateInfo.set(i, new TmfStateInterval(t, t, i, TmfStateValue.nullValue()));
+ }
+ }
+ return stateInfo;
}
- public String getFullAttributePath(int attributeQuark) {
- return attributeTree.getFullAttributeName(attributeQuark);
+ @Override
+ public ITmfStateInterval querySingleState(long t, int attributeQuark)
+ throws AttributeNotFoundException, TimeRangeException,
+ StateSystemDisposedException {
+ if (isDisposed) {
+ throw new StateSystemDisposedException();
+ }
+
+ ITmfStateInterval ret = transState.getIntervalAt(t, attributeQuark);
+ if (ret == null) {
+ /*
+ * The transient state did not have the information, let's look into
+ * the backend next.
+ */
+ ret = backend.doSingularQuery(t, attributeQuark);
+ }
+
+ /*
+ * Return a fake interval if we could not find anything in the history.
+ * We do NOT want to return 'null' here.
+ */
+ if (ret == null) {
+ return new TmfStateInterval(t, this.getCurrentEndTime(),
+ attributeQuark, TmfStateValue.nullValue());
+ }
+ return ret;
+ }
+
+ @Override
+ public ITmfStateInterval querySingleStackTop(long t, int stackAttributeQuark)
+ throws StateValueTypeException, AttributeNotFoundException,
+ TimeRangeException, StateSystemDisposedException {
+ ITmfStateValue curStackStateValue = querySingleState(t, stackAttributeQuark).getStateValue();
+
+ if (curStackStateValue.isNull()) {
+ /* There is nothing stored in this stack at this moment */
+ return null;
+ }
+ Integer curStackDepth = curStackStateValue.unboxInt();
+ if (curStackDepth <= 0) {
+ /*
+ * This attribute is an integer attribute, but it doesn't seem like
+ * it's used as a stack-attribute...
+ */
+ throw new StateValueTypeException();
+ }
+
+ int subAttribQuark = getQuarkRelative(stackAttributeQuark, curStackDepth.toString());
+ return querySingleState(t, subAttribQuark);
+ }
+
+ @Override
+ public List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
+ long t1, long t2) throws TimeRangeException,
+ AttributeNotFoundException, StateSystemDisposedException {
+ if (isDisposed) {
+ throw new StateSystemDisposedException();
+ }
+
+ List<ITmfStateInterval> intervals;
+ ITmfStateInterval currentInterval;
+ long ts, tEnd;
+
+ /* Make sure the time range makes sense */
+ if (t2 < t1) {
+ throw new TimeRangeException();
+ }
+
+ /* Set the actual, valid end time of the range query */
+ if (t2 > this.getCurrentEndTime()) {
+ tEnd = this.getCurrentEndTime();
+ } else {
+ tEnd = t2;
+ }
+
+ /* Get the initial state at time T1 */
+ intervals = new ArrayList<>();
+ currentInterval = querySingleState(t1, attributeQuark);
+ intervals.add(currentInterval);
+
+ /* Get the following state changes */
+ ts = currentInterval.getEndTime();
+ while (ts != -1 && ts < tEnd) {
+ ts++; /* To "jump over" to the next state in the history */
+ currentInterval = querySingleState(ts, attributeQuark);
+ intervals.add(currentInterval);
+ ts = currentInterval.getEndTime();
+ }
+ return intervals;
+ }
+
+ @Override
+ public List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
+ long t1, long t2, long resolution, IProgressMonitor monitor)
+ throws TimeRangeException, AttributeNotFoundException,
+ StateSystemDisposedException {
+ if (isDisposed) {
+ throw new StateSystemDisposedException();
+ }
+
+ List<ITmfStateInterval> intervals;
+ ITmfStateInterval currentInterval;
+ long ts, tEnd;
+
+ IProgressMonitor mon = monitor;
+ if (mon == null) {
+ mon = new NullProgressMonitor();
+ }
+
+ /* Make sure the time range makes sense */
+ if (t2 < t1 || resolution <= 0) {
+ throw new TimeRangeException();
+ }
+
+ /* Set the actual, valid end time of the range query */
+ if (t2 > this.getCurrentEndTime()) {
+ tEnd = this.getCurrentEndTime();
+ } else {
+ tEnd = t2;
+ }
+
+ /* Get the initial state at time T1 */
+ intervals = new ArrayList<>();
+ currentInterval = querySingleState(t1, attributeQuark);
+ intervals.add(currentInterval);
+
+ /*
+ * Iterate over the "resolution points". We skip unneeded queries in the
+ * case the current interval is longer than the resolution.
+ */
+ for (ts = t1; (currentInterval.getEndTime() != -1) && (ts < tEnd);
+ ts += resolution) {
+ if (mon.isCanceled()) {
+ return intervals;
+ }
+ if (ts <= currentInterval.getEndTime()) {
+ continue;
+ }
+ currentInterval = querySingleState(ts, attributeQuark);
+ intervals.add(currentInterval);
+ }
+
+ /* Add the interval at t2, if it wasn't included already. */
+ if (currentInterval.getEndTime() < tEnd) {
+ currentInterval = querySingleState(tEnd, attributeQuark);
+ intervals.add(currentInterval);
+ }
+ return intervals;
+ }
+
+ //--------------------------------------------------------------------------
+ // Debug methods
+ //--------------------------------------------------------------------------
+
+ static void logMissingInterval(int attribute, long timestamp) {
+ Activator.logInfo("No data found in history for attribute " + //$NON-NLS-1$
+ attribute + " at time " + timestamp + //$NON-NLS-1$
+ ", returning dummy interval"); //$NON-NLS-1$
}
/**
* Print out the contents of the inner structures.
- *
+ *
* @param writer
* The PrintWriter in which to print the output
*/
public void debugPrint(PrintWriter writer) {
- attributeTree.debugPrint(writer);
+ getAttributeTree().debugPrint(writer);
transState.debugPrint(writer);
+ backend.debugPrint(writer);
}
-}
\ No newline at end of file
+}