sh.props.sources.InMemory Maven / Gradle / Ivy
/*
* MIT License
*
* Copyright (c) 2021 - 2021 Mihai Bojin
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
package sh.props.sources;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import sh.props.Source;
import sh.props.annotations.Nullable;
/** Useful for tests, when the implementation requires overriding values. */
public class InMemory extends Source {
public static final boolean UPDATE_REGISTRY_ON_EVERY_WRITE = true;
public static final boolean UPDATE_REGISTRY_MANUALLY = false;
private final ConcurrentHashMap store = new ConcurrentHashMap<>();
private final boolean updateOnEveryWrite;
/**
* Class constructor that defaults to not notifying subscribers on {@link #put(String, String)}s.
*
* When you want to make a series of changes final, you will have to manually call {@link
* #refresh()}.
*/
public InMemory() {
this(UPDATE_REGISTRY_MANUALLY);
}
/**
* Class constructor.
*
* @param updateOnEveryWrite if true, {@link #refresh()} will be called on every put.
*/
public InMemory(boolean updateOnEveryWrite) {
this.updateOnEveryWrite = updateOnEveryWrite;
}
/**
* Retrieves an unmodifiable map containing all (key,value) pairs defined in the {@link #store}.
*
* @return a map
*/
@Override
public Map get() {
return Collections.unmodifiableMap(this.store);
}
/**
* Overridden for performance reasons, to avoid creating the unmodifiable {@link #store} map.
*
* @param key the key to retrieve
* @return a value, or null if the key was not found
*/
@Nullable
public String get(String key) {
return this.store.get(key);
}
/**
* Stores the specified (key, value) pair in memory.
*
* @param key the key to update
* @param value the value to set; pass null if you want to remove the key,value
* mapping
*/
public void put(String key, @Nullable String value) {
try {
if (value == null) {
this.store.remove(key);
return;
}
this.store.put(key, value);
} finally {
if (this.updateOnEveryWrite) {
// notify subscribers automatically on every update
this.refresh();
}
}
}
/**
* Removes the specified key from memory.
*
* @param key the key to remove from the store
*/
public void remove(String key) {
this.put(key, null);
}
}