Copyright (c) 2000, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Oakland Software Incorporated - added getSessionProperties and getPersistentProperties
    James Blackburn (Broadcom Corp.) - ongoing development
    Lars Vogel  - Bug 473427
/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Oakland Software Incorporated - added getSessionProperties and getPersistentProperties
 *     James Blackburn (Broadcom Corp.) - ongoing development
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 473427
 *******************************************************************************/
package org.eclipse.core.internal.resources;

import java.io.*;
import java.util.Map;
import org.eclipse.core.internal.localstore.FileStoreRoot;
import org.eclipse.core.internal.utils.*;
import org.eclipse.core.internal.watson.IElementTreeData;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.QualifiedName;

A data structure containing the in-memory state of a resource in the workspace.
/**
 * A data structure containing the in-memory state of a resource in the workspace.
 */
public class ResourceInfo implements IElementTreeData, ICoreConstants, IStringPoolParticipant {
	protected static final int LOWER = 0xFFFF;
	protected static final int UPPER = 0xFFFF0000;

	
This field stores the resource modification stamp in the lower two bytes,
and the character set generation count in the higher two bytes.
/**
	 * This field stores the resource modification stamp in the lower two bytes,
	 * and the character set generation count in the higher two bytes.
	 */
	protected volatile int charsetAndContentId = 0;

	
The file system root that this resource is stored in
/**
	 * The file system root that this resource is stored in
	 */
	protected FileStoreRoot fileStoreRoot;

	
Set of flags which reflect various states of the info (used, derived, ...). /** Set of flags which reflect various states of the info (used, derived, ...). */
	protected int flags = 0;

	
Local sync info /** Local sync info */
	// thread safety: (Concurrency004)
	protected volatile long localInfo = I_NULL_SYNC_INFO;

	
This field stores the sync info generation in the lower two bytes, and
the marker generation count in the upper two bytes.
/**
	 * This field stores the sync info generation in the lower two bytes, and
	 * the marker generation count in the upper two bytes.
	 */
	protected volatile int markerAndSyncStamp;

	
The collection of markers for this resource. /** The collection of markers for this resource. */
	protected MarkerSet markers = null;

	
Modification stamp /** Modification stamp */
	protected long modStamp = 0;

	
Unique node identifier /** Unique node identifier */
	// thread safety: (Concurrency004)
	protected volatile long nodeId = 0;

	
The properties which are maintained for the lifecycle of the workspace.

This field is declared as the implementing class rather than the
interface so we ensure that we get it right since we are making certain
assumptions about the object type w.r.t. casting.
/**
	 * The properties which are maintained for the lifecycle of the workspace.
	 * <p>
	 * This field is declared as the implementing class rather than the
	 * interface so we ensure that we get it right since we are making certain
	 * assumptions about the object type w.r.t. casting.
	 */
	protected ObjectMap<QualifiedName, Object> sessionProperties = null;

	
The table of sync information.

This field is declared as the implementing class rather than the
interface so we ensure that we get it right since we are making certain
assumptions about the object type w.r.t. casting.
/**
	 * The table of sync information.
	 * <p>
	 * This field is declared as the implementing class rather than the
	 * interface so we ensure that we get it right since we are making certain
	 * assumptions about the object type w.r.t. casting.
	 */
	protected ObjectMap<QualifiedName, Object> syncInfo = null;

	
Returns the integer value stored in the indicated part of this info's flags.
/**
	 * Returns the integer value stored in the indicated part of this info's flags.
	 */
	protected static int getBits(int flags, int mask, int start) {
		return (flags & mask) >> start;
	}

	
Returns the type setting for this info.  Valid values are
FILE, FOLDER, PROJECT,
/**
	 * Returns the type setting for this info.  Valid values are
	 * FILE, FOLDER, PROJECT,
	 */
	public static int getType(int flags) {
		return getBits(flags, M_TYPE, M_TYPE_START);
	}

	
Returns true if all of the bits indicated by the mask are set.
/**
	 * Returns true if all of the bits indicated by the mask are set.
	 */
	public static boolean isSet(int flags, int mask) {
		return (flags & mask) == mask;
	}

	
Clears all of the bits indicated by the mask.
/**
	 * Clears all of the bits indicated by the mask.
	 */
	public void clear(int mask) {
		flags &= ~mask;
	}

	public void clearModificationStamp() {
		modStamp = IResource.NULL_STAMP;
	}

	public void clearCharsetGenerationCount() {
		charsetAndContentId = getContentId();
	}

	public synchronized void clearSessionProperties() {
		sessionProperties = null;
	}

	@Override
	public Object clone() {
		try {
			return super.clone();
		} catch (CloneNotSupportedException e) {
			return null; // never gets here.
		}
	}

	public int getCharsetGenerationCount() {
		return charsetAndContentId >> 16;
	}

	public int getContentId() {
		return charsetAndContentId & LOWER;
	}

	public FileStoreRoot getFileStoreRoot() {
		return fileStoreRoot;
	}

	
Returns the set of flags for this info.
/**
	 * Returns the set of flags for this info.
	 */
	public int getFlags() {
		return flags;
	}

	
Gets the local-relative sync information.
/**
	 * Gets the local-relative sync information.
	 */
	public long getLocalSyncInfo() {
		return localInfo;
	}

	
Returns the marker generation count.
The count is incremented whenever markers on the resource change.
/**
	 * Returns the marker generation count.
	 * The count is incremented whenever markers on the resource change.
	 */
	public int getMarkerGenerationCount() {
		return markerAndSyncStamp >> 16;
	}

	
Returns a copy of the collection of makers on this resource.
null is returned if there are none.
/**
	 * Returns a copy of the collection of makers on this resource.
	 * <code>null</code> is returned if there are none.
	 */
	public MarkerSet getMarkers() {
		return getMarkers(true);
	}

	
Returns the collection of makers on this resource.
null is returned if there are none.
/**
	 * Returns the collection of makers on this resource.
	 * <code>null</code> is returned if there are none.
	 */
	public MarkerSet getMarkers(boolean makeCopy) {
		if (markers == null)
			return null;
		return makeCopy ? (MarkerSet) markers.clone() : markers;
	}

	public long getModificationStamp() {
		return modStamp;
	}

	public long getNodeId() {
		return nodeId;
	}

	
Returns the property store associated with this info.  The return value may be null.
/**
	 * Returns the property store associated with this info.  The return value may be null.
	 */
	public Object getPropertyStore() {
		return null;
	}

	
Returns a copy of the map of this resource session properties.
An empty map is returned if there are none.
/**
	 * Returns a copy of the map of this resource session properties.
	 * An empty map is returned if there are none.
	 */
	@SuppressWarnings({"unchecked"})
	public Map<QualifiedName, Object> getSessionProperties() {
		// thread safety: (Concurrency001)
		ObjectMap<QualifiedName, Object> temp = sessionProperties;
		if (temp == null)
			temp = new ObjectMap<>(5);
		else
			temp = (ObjectMap<QualifiedName, Object>) sessionProperties.clone();
		return temp;
	}

	
Returns the value of the identified session property
/**
	 * Returns the value of the identified session property
	 */
	public Object getSessionProperty(QualifiedName name) {
		// thread safety: (Concurrency001)
		Map<QualifiedName, Object> temp = sessionProperties;
		if (temp == null)
			return null;
		return temp.get(name);
	}

	
The parameter to this method is the implementing class rather than the
interface so we ensure that we get it right since we are making certain
assumptions about the object type w.r.t. casting.
/**
	 * The parameter to this method is the implementing class rather than the
	 * interface so we ensure that we get it right since we are making certain
	 * assumptions about the object type w.r.t. casting.
	 */
	@SuppressWarnings({"unchecked"})
	public synchronized ObjectMap<QualifiedName, Object> getSyncInfo(boolean makeCopy) {
		if (syncInfo == null)
			return null;
		return makeCopy ? (ObjectMap<QualifiedName, Object>) syncInfo.clone() : syncInfo;
	}

	public synchronized byte[] getSyncInfo(QualifiedName id, boolean makeCopy) {
		// thread safety: (Concurrency001)
		byte[] b;
		if (syncInfo == null)
			return null;
		b = (byte[]) syncInfo.get(id);
		return b == null ? null : (makeCopy ? (byte[]) b.clone() : b);
	}

	
Returns the sync information generation count.
The count is incremented whenever sync info on the resource changes.
/**
	 * Returns the sync information generation count.
	 * The count is incremented whenever sync info on the resource changes.
	 */
	public int getSyncInfoGenerationCount() {
		return markerAndSyncStamp & LOWER;
	}

	
Returns the type setting for this info.  Valid values are
FILE, FOLDER, PROJECT,
/**
	 * Returns the type setting for this info.  Valid values are
	 * FILE, FOLDER, PROJECT,
	 */
	public int getType() {
		return getType(flags);
	}

	
Increments the charset generation count.
The count is incremented whenever the encoding on the resource changes.
/**
	 * Increments the charset generation count.
	 * The count is incremented whenever the encoding on the resource changes.
	 */
	public void incrementCharsetGenerationCount() {
		//increment high order bits
		charsetAndContentId = ((charsetAndContentId + LOWER + 1) & UPPER) + (charsetAndContentId & LOWER);
	}

	
Mark this resource info as having changed content
/**
	 * Mark this resource info as having changed content
	 */
	public void incrementContentId() {
		//increment low order bits
		charsetAndContentId = (charsetAndContentId & UPPER) + ((charsetAndContentId + 1) & LOWER);
	}

	
Increments the marker generation count.
The count is incremented whenever markers on the resource change.
/**
	 * Increments the marker generation count.
	 * The count is incremented whenever markers on the resource change.
	 */
	public void incrementMarkerGenerationCount() {
		//increment high order bits
		markerAndSyncStamp = ((markerAndSyncStamp + LOWER + 1) & UPPER) + (markerAndSyncStamp & LOWER);
	}

	
Change the modification stamp to indicate that this resource has changed.
The exact value of the stamp doesn't matter, as long as it can be used to
distinguish two arbitrary resource generations.
/**
	 * Change the modification stamp to indicate that this resource has changed.
	 * The exact value of the stamp doesn't matter, as long as it can be used to
	 * distinguish two arbitrary resource generations.
	 */
	public void incrementModificationStamp() {
		modStamp++;
	}

	
Increments the sync information generation count.
The count is incremented whenever sync info on the resource changes.
/**
	 * Increments the sync information generation count.
	 * The count is incremented whenever sync info on the resource changes.
	 */
	public void incrementSyncInfoGenerationCount() {
		//increment low order bits
		markerAndSyncStamp = (markerAndSyncStamp & UPPER) + ((markerAndSyncStamp + 1) & LOWER);
	}

	
Returns true if all of the bits indicated by the mask are set.
/**
	 * Returns true if all of the bits indicated by the mask are set.
	 */
	public boolean isSet(int mask) {
		return (flags & mask) == mask;
	}

	public void readFrom(int newFlags, DataInput input) throws IOException {
		// The flags for this info are read by the visitor (flattener).
		// See Workspace.readElement().  This allows the reader to look ahead
		// and see what type of info is being loaded.
		this.flags = newFlags;
		localInfo = input.readLong();
		nodeId = input.readLong();
		charsetAndContentId = input.readInt() & LOWER;
		modStamp = input.readLong();
	}

	
Sets all of the bits indicated by the mask.
/**
	 * Sets all of the bits indicated by the mask.
	 */
	public void set(int mask) {
		flags |= mask;
	}

	
Sets the value of the indicated bits to be the given value.
/**
	 * Sets the value of the indicated bits to be the given value.
	 */
	protected void setBits(int mask, int start, int value) {
		int baseMask = mask >> start;
		int newValue = (value & baseMask) << start;
		// thread safety: (guarantee atomic assignment)
		int temp = flags;
		temp &= ~mask;
		temp |= newValue;
		flags = temp;
	}

	public void setFileStoreRoot(FileStoreRoot fileStoreRoot) {
		this.fileStoreRoot = fileStoreRoot;
	}

	
Sets the flags for this info.
/**
	 * Sets the flags for this info.
	 */
	protected void setFlags(int value) {
		flags = value;
	}

	
Sets the local-relative sync information.
/**
	 * Sets the local-relative sync information.
	 */
	public void setLocalSyncInfo(long info) {
		localInfo = info;
	}

	
Sets the collection of makers for this resource.
null is passed in if there are no markers.
/**
	 * Sets the collection of makers for this resource.
	 * <code>null</code> is passed in if there are no markers.
	 */
	public void setMarkers(MarkerSet value) {
		markers = value;
	}

	
Sets the resource modification stamp.
/**
	 * Sets the resource modification stamp.
	 */
	public void setModificationStamp(long value) {
		this.modStamp = value;
	}

	/**
	 *
	 */
	public void setNodeId(long id) {
		nodeId = id;
		// Resource modification stamp starts from current nodeId
		// so future generations are distinguishable (bug 160728)
		if (modStamp == 0)
			modStamp = nodeId;
	}

	
Sets the property store associated with this info.  The value may be null.
/**
	 * Sets the property store associated with this info.  The value may be null.
	 */
	public void setPropertyStore(Object value) {
		// needs to be implemented on subclasses
	}

	
Sets the identified session property to the given value.  If
the value is null, the property is removed.
/**
	 * Sets the identified session property to the given value.  If
	 * the value is null, the property is removed.
	 */
	@SuppressWarnings({"unchecked"})
	public synchronized void setSessionProperty(QualifiedName name, Object value) {
		// thread safety: (Concurrency001)
		if (value == null) {
			if (sessionProperties == null)
				return;
			ObjectMap<QualifiedName, Object> temp = (ObjectMap<QualifiedName, Object>) sessionProperties.clone();
			temp.remove(name);
			if (temp.isEmpty())
				sessionProperties = null;
			else
				sessionProperties = temp;
		} else {
			ObjectMap<QualifiedName, Object> temp = sessionProperties;
			if (temp == null)
				temp = new ObjectMap<>(5);
			else
				temp = (ObjectMap<QualifiedName, Object>) sessionProperties.clone();
			temp.put(name, value);
			sessionProperties = temp;
		}
	}

	
The parameter to this method is the implementing class rather than the
interface so we ensure that we get it right since we are making certain
assumptions about the object type w.r.t. casting.
/**
	 * The parameter to this method is the implementing class rather than the
	 * interface so we ensure that we get it right since we are making certain
	 * assumptions about the object type w.r.t. casting.
	 */
	protected void setSyncInfo(ObjectMap<QualifiedName, Object> syncInfo) {
		this.syncInfo = syncInfo;
	}

	public synchronized void setSyncInfo(QualifiedName id, byte[] value) {
		if (value == null) {
			//delete sync info
			if (syncInfo == null)
				return;
			syncInfo.remove(id);
			if (syncInfo.isEmpty())
				syncInfo = null;
		} else {
			//add sync info
			if (syncInfo == null)
				syncInfo = new ObjectMap<>(5);
			syncInfo.put(id, value.clone());
		}
	}

	
Sets the type for this info to the given value.  Valid values are
FILE, FOLDER, PROJECT
/**
	 * Sets the type for this info to the given value.  Valid values are
	 * FILE, FOLDER, PROJECT
	 */
	public void setType(int value) {
		setBits(M_TYPE, M_TYPE_START, value);
	}

	/* (non-Javadoc
	 * Method declared on IStringPoolParticipant
	 */
	@Override
	public void shareStrings(StringPool set) {
		ObjectMap<QualifiedName, Object> map = syncInfo;
		if (map != null)
			map.shareStrings(set);
		map = sessionProperties;
		if (map != null)
			map.shareStrings(set);
		MarkerSet markerSet = markers;
		if (markerSet != null)
			markerSet.shareStrings(set);
	}

	public void writeTo(DataOutput output) throws IOException {
		// The flags for this info are written by the visitor (flattener).
		// See SaveManager.writeElement().  This allows the reader to look ahead
		// and see what type of info is being loaded.
		output.writeLong(localInfo);
		output.writeLong(nodeId);
		output.writeInt(getContentId());
		output.writeLong(modStamp);
	}
}