/* Copyright (c) 2012-2013 Boundless and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Distribution License v1.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/org/documents/edl-v10.html
*
* Contributors:
* Gabriel Roldan (Boundless) - initial implementation
*/
package org.locationtech.geogig.storage.memory;
import static com.google.common.base.Preconditions.checkNotNull;
import static org.locationtech.geogig.api.Ref.TRANSACTIONS_PREFIX;
import java.util.Map;
import org.locationtech.geogig.api.ObjectId;
import org.locationtech.geogig.storage.AbstractRefDatabase;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;
/**
* Provides an implementation of a GeoGig ref database that utilizes the heap for the storage of
* refs.
*/
public class HeapRefDatabase extends AbstractRefDatabase {
private Map<String, String> refs;
/**
* Creates the reference database.
*/
@Override
public void create() {
if (refs == null) {
refs = Maps.newTreeMap();
}
}
/**
* Closes the reference database.
*/
@Override
public void close() {
if (refs != null) {
refs.clear();
refs = null;
}
}
/**
* @param name the name of the ref (e.g. {@code "refs/remotes/origin"}, etc).
* @return the ref, or {@code null} if it doesn't exist
*/
@Override
public String getRef(String name) {
String val = refs.get(name);
if (val == null) {
return null;
}
try {
ObjectId.valueOf(val);
} catch (IllegalArgumentException e) {
throw e;
}
return val;
}
/**
* @param name the name of the ref
* @param value the value of the ref
* @return {@code null} if the ref didn't exist already, its old value otherwise
*/
@Override
public void putRef(String name, String value) {
checkNotNull(name);
checkNotNull(value);
ObjectId.valueOf(value);
refs.put(name, value);
}
/**
* @param refName the name of the ref to remove (e.g. {@code "HEAD"},
* {@code "refs/remotes/origin"}, etc).
* @return the value of the ref before removing it, or {@code null} if it didn't exist
*/
@Override
public String remove(String refName) {
checkNotNull(refName);
String oldValue = refs.remove(refName);
return oldValue;
}
/**
* @param name the name of the symbolic ref (e.g. {@code "HEAD"}, etc).
* @return the ref, or {@code null} if it doesn't exist
*/
@Override
public String getSymRef(String name) {
checkNotNull(name);
String value = refs.get(name);
if (value == null) {
return null;
}
if (!value.startsWith("ref: ")) {
throw new IllegalArgumentException(name + " is not a symbolic ref: '" + value + "'");
}
return value.substring("ref: ".length());
}
/**
* @param name the name of the symbolic ref
* @param val the value of the symbolic ref
* @return {@code null} if the ref didn't exist already, its old value otherwise
*/
@Override
public void putSymRef(String name, String val) {
checkNotNull(name);
checkNotNull(val);
val = "ref: " + val;
refs.put(name, val);
}
private static class RefPrefixPredicate implements Predicate<String> {
private final String prefix;
RefPrefixPredicate(final String prefix) {
this.prefix = prefix;
}
@Override
public boolean apply(String refName) {
return refName.startsWith(prefix);
}
}
/**
* @return all known references under the "refs" namespace (i.e. not top level ones like HEAD,
* etc), key'ed by ref name
*/
@Override
public Map<String, String> getAll() {
Predicate<String> filter = Predicates.not(new RefPrefixPredicate(TRANSACTIONS_PREFIX));
Map<String, String> allButTransactions = Maps.filterKeys(ImmutableMap.copyOf(this.refs),
filter);
return allButTransactions;
}
@Override
public Map<String, String> getAll(final String prefix) {
Preconditions.checkNotNull(prefix);
Predicate<String> filter = new RefPrefixPredicate(prefix);
return Maps.filterKeys(ImmutableMap.copyOf(this.refs), filter);
}
@Override
public Map<String, String> removeAll(final String namespace) {
Predicate<String> keyPredicate = new Predicate<String>() {
@Override
public boolean apply(String refName) {
return refName.startsWith(namespace);
}
};
Map<String, String> removed = Maps.filterKeys(ImmutableMap.copyOf(this.refs), keyPredicate);
for (String key : removed.keySet()) {
refs.remove(key);
}
return null;
}
@Override
public void configure() {
// No-op
}
@Override
public void checkConfig() {
// No-op
}
}