/*
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.flex.compiler.internal.units;
import java.io.File;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.apache.flex.compiler.projects.ICompilerProject;
import org.apache.flex.compiler.units.ICompilationUnit;
/**
* Maps {@link File}'s to collections of {@link ICompilationUnit}'s whose root
* files are those files.
*/
public final class StringToCompilationUnitMap
{
// would like to use a HashSet to store weak references, but that doesn't
// work, so use a WeakHashMap where the value is always PRESENT.
private static final Object PRESENT = new Object();
private static final Map<String, Object> EMPTY_MAP = Collections.emptyMap();
private final Lock readLock;
private final Lock writeLock;
private Map<String, Object> map;
/**
* Constructor.
*/
public StringToCompilationUnitMap()
{
this(EMPTY_MAP);
}
private StringToCompilationUnitMap(Map<String, Object> map)
{
this.map = map;
ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
readLock = lock.readLock();
writeLock = lock.writeLock();
}
/**
* Gets a {@link Collection} of invisible {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
* @param sortKey String to search the map for.
* @return Array of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
*/
public Collection<WeakReference<ICompilationUnit>> getInvisible(String sortKey)
{
readLock.lock();
try
{
return valueToCollection(map.get(sortKey), null, Visibility.INVISIBLE_ONLY);
}
finally
{
readLock.unlock();
}
}
/**
* Gets a {@link Collection} of visible and invisible {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
* @param sortKey String to search the map for.
* @return Array of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
*/
public Collection<WeakReference<ICompilationUnit>> getVisibleAndInvisible(String sortKey)
{
readLock.lock();
try
{
return valueToCollection(map.get(sortKey), null, Visibility.ALL);
}
finally
{
readLock.unlock();
}
}
/**
* Gets a {@link Collection} of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
* @param sortKey String to search the map for.
* @return Array of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
*/
public Collection<WeakReference<ICompilationUnit>> get(String sortKey)
{
readLock.lock();
try
{
return valueToCollection(map.get(sortKey), null, Visibility.VISIBLE_ONLY);
}
finally
{
readLock.unlock();
}
}
/**
* Gets the a {@link Collection} of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file for a specific project
* @param sortKey String to search the map for.
* @param project Project to search the map for.
* @return Array of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
*/
public Collection<WeakReference<ICompilationUnit>> get(String sortKey, ICompilerProject project)
{
readLock.lock();
try
{
return valueToCollection(map.get(sortKey), project, Visibility.VISIBLE_ONLY);
}
finally
{
readLock.unlock();
}
}
/**
* Gets the a {@link Collection} of invisible {@link ICompilationUnit}'s that refer to
* the specified file as their root source file for a specific project
* @param sortKey String to search the map for.
* @param project Project to search the map for.
* @return Array of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
*/
public Collection<WeakReference<ICompilationUnit>> getInvisible(String sortKey, ICompilerProject project)
{
readLock.lock();
try
{
return valueToCollection(map.get(sortKey), project, Visibility.INVISIBLE_ONLY);
}
finally
{
readLock.unlock();
}
}
/**
* Adds entries for multiple file names all referenced from the same compilation unit.
* @param files An array of file paths.
* @param cu A compilation unit.
*/
public void add(String[] files, ICompilationUnit cu)
{
writeLock.lock();
try
{
for (String file : files)
{
add(file, cu);
}
}
finally
{
writeLock.unlock();
}
}
/**
* Adds the specified {@link ICompilationUnit} whose root source file
* is the specified File to the map.
* @param sortKey String to add to the map.
* @param cu {@link ICompilationUnit} to add to the map.
*/
@SuppressWarnings("unchecked")
public void add(String sortKey, ICompilationUnit cu)
{
writeLock.lock();
try
{
if (map == EMPTY_MAP)
map = new HashMap<String, Object>();
Object existing = map.get(sortKey);
if (existing == null)
{
map.put(sortKey, new WeakReference<ICompilationUnit>(cu));
}
else if (existing instanceof WeakHashMap<?,?>)
{
WeakHashMap<ICompilationUnit,Object> collection = (WeakHashMap<ICompilationUnit,Object>)existing;
collection.put(cu, PRESENT);
}
else
{
assert existing instanceof WeakReference<?>;
WeakHashMap<ICompilationUnit,Object> collection = new WeakHashMap<ICompilationUnit,Object>(2);
collection.put(((WeakReference<ICompilationUnit>)existing).get(), PRESENT);
collection.put(cu, PRESENT);
map.put(sortKey, collection);
}
}
finally
{
writeLock.unlock();
}
}
/**
* Removes the specified File from the map.
* @param sortKey String to remove from the map.
*/
void remove(String sortKey)
{
writeLock.lock();
try
{
map.remove(sortKey);
if (map.isEmpty())
map = EMPTY_MAP;
}
finally
{
writeLock.unlock();
}
}
/**
* Removes the specified File within a project from the map.
* @param sortKey String to remove from the map.
* @param project Project to remove from the map.
* @return Array of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file.
*/
@SuppressWarnings("unchecked")
Collection<ICompilationUnit> remove(String sortKey, ICompilerProject project)
{
assert project != null;
writeLock.lock();
try
{
Object mapValue = map.remove(sortKey);
if (mapValue == null)
{
return Collections.emptyList();
}
else if (mapValue instanceof WeakHashMap<?,?>)
{
WeakHashMap<ICompilationUnit, Object> collection = (WeakHashMap<ICompilationUnit, Object>)mapValue;
List<ICompilationUnit> result = new ArrayList<ICompilationUnit>(collection.size());
Iterator<Map.Entry<ICompilationUnit, Object>> iter = collection.entrySet().iterator();
while (iter.hasNext())
{
ICompilationUnit compilationUnit = iter.next().getKey();
// We are dealing with a WeakHashMap, here so it
// is possible that the CompilationUnit has been gc'd.
if (compilationUnit != null)
{
// The CompilationUnit might not be in a project
// any more. We should only return CompilationUnit's
// that are in a project.
ICompilerProject projFromCU = compilationUnit.getProject();
if ((projFromCU != null) && (projFromCU == project))
{
result.add(compilationUnit);
iter.remove();
}
}
}
if (!collection.isEmpty())
map.put(sortKey, collection);
return Collections.unmodifiableList(result);
}
else
{
ICompilationUnit compilationUnit = ((WeakReference<ICompilationUnit>)mapValue).get();
if (compilationUnit == null)
return Collections.emptyList();
// if projects don't match, add the map value back in, otherwise return the
// removed CU
if ((compilationUnit != null) && (compilationUnit.getProject() == project))
return Collections.singletonList(compilationUnit);
else
map.put(sortKey, mapValue);
return Collections.emptyList();
}
}
finally
{
if (map.isEmpty())
map = EMPTY_MAP;
writeLock.unlock();
}
}
/**
* Removes the specified CompilationUnit from the path to compilation unit map, removing
* the path only when there are no compilation units remaining
* @param sortKey String to remove from the map.
* @param cuToRemove CU to remove from the map.
* @return Array of {@link ICompilationUnit}'s that refer to
* the specified file as their root source file. An empty collection
* if no more CompilationUnits refer to this path
*/
@SuppressWarnings("unchecked")
public Collection<ICompilationUnit> remove(String sortKey, ICompilationUnit cuToRemove)
{
assert cuToRemove != null;
writeLock.lock();
try
{
Object mapValue = map.remove(sortKey);
if (mapValue == null)
{
return Collections.emptyList();
}
else if (mapValue instanceof WeakHashMap<?,?>)
{
WeakHashMap<ICompilationUnit, Object> collection = (WeakHashMap<ICompilationUnit, Object>)mapValue;
List<ICompilationUnit> result = new ArrayList<ICompilationUnit>(collection.size());
Iterator<Map.Entry<ICompilationUnit, Object>> iter = collection.entrySet().iterator();
while (iter.hasNext())
{
ICompilationUnit compilationUnit = iter.next().getKey();
// We are dealing with a WeakHashMap, here so it
// is possible that the CompilationUnit has been gc'd.
if ((compilationUnit != null) && (compilationUnit == cuToRemove))
{
result.add(compilationUnit);
iter.remove();
}
}
if (!collection.isEmpty())
map.put(sortKey, collection);
return Collections.unmodifiableList(result);
}
else
{
ICompilationUnit compilationUnit = ((WeakReference<ICompilationUnit>)mapValue).get();
if (compilationUnit == null)
return Collections.emptyList();
// if compilation units don't match, add the map value back in, otherwise
// return the removed CU
if ((compilationUnit != null) && (compilationUnit == cuToRemove))
return Collections.singletonList(compilationUnit);
else
map.put(sortKey, mapValue);
return Collections.emptyList();
}
}
finally
{
if (map.isEmpty())
map = EMPTY_MAP;
writeLock.unlock();
}
}
@SuppressWarnings("unchecked")
private static Collection<WeakReference<ICompilationUnit>> valueToCollection(Object value, ICompilerProject project, Visibility visibility)
{
if (value instanceof WeakHashMap<?,?>)
{
WeakHashMap<ICompilationUnit, Object> collection = (WeakHashMap<ICompilationUnit, Object>)value;
List<WeakReference<ICompilationUnit>> result = new ArrayList<WeakReference<ICompilationUnit>>(collection.size());
for (ICompilationUnit compilationUnit : collection.keySet())
{
// We are dealing with a WeakHashMap, here so it
// is possible that the CompilationUnit has been gc'd.
if (compilationUnit != null)
{
// The CompilationUnit might not be in a project
// any more. We should only return CompilationUnit's
// that are in a project.
ICompilerProject projFromCU = compilationUnit.getProject();
if ((projFromCU != null) && ((project == null) || (projFromCU == project)) && visibility.match(compilationUnit))
result.add(new WeakReference<ICompilationUnit>(compilationUnit));
}
}
return Collections.unmodifiableList(result);
}
else if (value != null)
{
assert value instanceof WeakReference<?>;
WeakReference<ICompilationUnit> cuRef = (WeakReference<ICompilationUnit>)value;
ICompilationUnit compilationUnit = cuRef.get();
// either not limiting search to projects, or projects match so add the CU
if ((compilationUnit != null) && ((project == null) || (compilationUnit.getProject() == project)) && visibility.match(compilationUnit))
return Collections.singletonList(cuRef);
else
return Collections.emptyList();
}
else
{
return Collections.emptyList();
}
}
private static enum Visibility
{
INVISIBLE_ONLY,
VISIBLE_ONLY,
ALL;
private boolean match(ICompilationUnit cu)
{
switch (this)
{
case INVISIBLE_ONLY:
return cu.isInvisible();
case VISIBLE_ONLY:
return !cu.isInvisible();
case ALL:
return true;
default:
assert false : "Unhandled visibility!";
}
return false;
}
}
}