/*
 * Copyright (C) 2016 Ericsson and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
package org.eclipse.jgit.lib;

import java.util.concurrent.TimeUnit;

Configuration parameters for JVM-wide repository cache used by JGit.
Since:
4.4/**
 * Configuration parameters for JVM-wide repository cache used by JGit.
 *
 * @since 4.4
 */
public class RepositoryCacheConfig {

	
Set cleanupDelayMillis to this value in order to switch off time-based
cache eviction. Expired cache entries will only be evicted when
RepositoryCache.clearExpired or RepositoryCache.clear are called.
/**
	 * Set cleanupDelayMillis to this value in order to switch off time-based
	 * cache eviction. Expired cache entries will only be evicted when
	 * RepositoryCache.clearExpired or RepositoryCache.clear are called.
	 */
	public static final long NO_CLEANUP = 0;

	
Set cleanupDelayMillis to this value in order to auto-set it to minimum
of 1/10 of expireAfterMillis and 10 minutes
/**
	 * Set cleanupDelayMillis to this value in order to auto-set it to minimum
	 * of 1/10 of expireAfterMillis and 10 minutes
	 */
	public static final long AUTO_CLEANUP_DELAY = -1;

	private long expireAfterMillis;

	private long cleanupDelayMillis;

	
Create a default configuration.
/**
	 * Create a default configuration.
	 */
	public RepositoryCacheConfig() {
		expireAfterMillis = TimeUnit.HOURS.toMillis(1);
		cleanupDelayMillis = AUTO_CLEANUP_DELAY;
	}

	
Get the time an unused repository should be expired and be evicted from
the RepositoryCache in milliseconds.
Returns:
the time an unused repository should be expired and be evicted
        from the RepositoryCache in milliseconds. Default is 1
        hour./**
	 * Get the time an unused repository should be expired and be evicted from
	 * the RepositoryCache in milliseconds.
	 *
	 * @return the time an unused repository should be expired and be evicted
	 *         from the RepositoryCache in milliseconds. <b>Default is 1
	 *         hour.</b>
	 */
	public long getExpireAfter() {
		return expireAfterMillis;
	}

	
Set the time an unused repository should be expired and be evicted from
the RepositoryCache in milliseconds.
Params:
expireAfterMillis – 
           the time an unused repository should be expired and be evicted
           from the RepositoryCache in milliseconds./**
	 * Set the time an unused repository should be expired and be evicted from
	 * the RepositoryCache in milliseconds.
	 *
	 * @param expireAfterMillis
	 *            the time an unused repository should be expired and be evicted
	 *            from the RepositoryCache in milliseconds.
	 */
	public void setExpireAfter(long expireAfterMillis) {
		this.expireAfterMillis = expireAfterMillis;
	}

	
Get the delay between the periodic cleanup of expired repository in
milliseconds.
Returns:
the delay between the periodic cleanup of expired repository in
        milliseconds. Default is minimum of 1/10 of expireAfterMillis
        and 10 minutes/**
	 * Get the delay between the periodic cleanup of expired repository in
	 * milliseconds.
	 *
	 * @return the delay between the periodic cleanup of expired repository in
	 *         milliseconds. <b>Default is minimum of 1/10 of expireAfterMillis
	 *         and 10 minutes</b>
	 */
	public long getCleanupDelay() {
		if (cleanupDelayMillis < 0) {
			return Math.min(expireAfterMillis / 10,
					TimeUnit.MINUTES.toMillis(10));
		}
		return cleanupDelayMillis;
	}

	
Set the delay between the periodic cleanup of expired repository in
milliseconds.
Params:
cleanupDelayMillis –  the delay between the periodic cleanup of expired repository in milliseconds. Set it to AUTO_CLEANUP_DELAY to automatically derive cleanup delay from expireAfterMillis. 
 Set it to NO_CLEANUP in order to switch off cache expiration. 

           If cache expiration is switched off the JVM still can evict
           cache entries when the JVM is running low on available heap
           memory./**
	 * Set the delay between the periodic cleanup of expired repository in
	 * milliseconds.
	 *
	 * @param cleanupDelayMillis
	 *            the delay between the periodic cleanup of expired repository
	 *            in milliseconds. Set it to {@link #AUTO_CLEANUP_DELAY} to
	 *            automatically derive cleanup delay from expireAfterMillis.
	 *            <p>
	 *            Set it to {@link #NO_CLEANUP} in order to switch off cache
	 *            expiration.
	 *            <p>
	 *            If cache expiration is switched off the JVM still can evict
	 *            cache entries when the JVM is running low on available heap
	 *            memory.
	 */
	public void setCleanupDelay(long cleanupDelayMillis) {
		this.cleanupDelayMillis = cleanupDelayMillis;
	}

	
Update properties by setting fields from the configuration.

If a property is not defined in the configuration, then it is left
unmodified.
Params:
config – 
           configuration to read properties from.
Returns:
this./**
	 * Update properties by setting fields from the configuration.
	 * <p>
	 * If a property is not defined in the configuration, then it is left
	 * unmodified.
	 *
	 * @param config
	 *            configuration to read properties from.
	 * @return {@code this}.
	 */
	public RepositoryCacheConfig fromConfig(Config config) {
		setExpireAfter(
				config.getTimeUnit("core", null, "repositoryCacheExpireAfter", //$NON-NLS-1$//$NON-NLS-2$
						getExpireAfter(), TimeUnit.MILLISECONDS));
		setCleanupDelay(
				config.getTimeUnit("core", null, "repositoryCacheCleanupDelay", //$NON-NLS-1$ //$NON-NLS-2$
						AUTO_CLEANUP_DELAY, TimeUnit.MILLISECONDS));
		return this;
	}

	
Install this configuration as the live settings.

The new configuration is applied immediately.
/**
	 * Install this configuration as the live settings.
	 * <p>
	 * The new configuration is applied immediately.
	 */
	public void install() {
		RepositoryCache.reconfigure(this);
	}
}