/*
 * Copyright (C) 2011, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
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 * without modification, are permitted provided that the following
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 *
 * - Redistributions of source code must retain the above copyright
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 * - Redistributions in binary form must reproduce the above
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 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
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 * - Neither the name of the Eclipse Foundation, Inc. nor the
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package org.eclipse.jgit.internal.storage.dfs;

import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_CORE_SECTION;
import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_DFS_SECTION;
import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_BLOCK_LIMIT;
import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_BLOCK_SIZE;
import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_CONCURRENCY_LEVEL;
import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_STREAM_RATIO;

import java.text.MessageFormat;
import java.util.function.Consumer;

import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.Config;

Configuration parameters for DfsBlockCache. /**
 * Configuration parameters for
 * {@link org.eclipse.jgit.internal.storage.dfs.DfsBlockCache}.
 */
public class DfsBlockCacheConfig {
	
1024 (number of bytes in one kibibyte/kilobyte) /** 1024 (number of bytes in one kibibyte/kilobyte) */
	public static final int KB = 1024;

	
1024 KB (number of bytes in one mebibyte/megabyte) /** 1024 {@link #KB} (number of bytes in one mebibyte/megabyte) */
	public static final int MB = 1024 * KB;

	private long blockLimit;
	private int blockSize;
	private double streamRatio;
	private int concurrencyLevel;

	private Consumer<Long> refLock;

	
Create a default configuration.
/**
	 * Create a default configuration.
	 */
	public DfsBlockCacheConfig() {
		setBlockLimit(32 * MB);
		setBlockSize(64 * KB);
		setStreamRatio(0.30);
		setConcurrencyLevel(32);
	}

	
Get maximum number bytes of heap memory to dedicate to caching pack file
data.
Returns:
maximum number bytes of heap memory to dedicate to caching pack
        file data. Default is 32 MB./**
	 * Get maximum number bytes of heap memory to dedicate to caching pack file
	 * data.
	 *
	 * @return maximum number bytes of heap memory to dedicate to caching pack
	 *         file data. <b>Default is 32 MB.</b>
	 */
	public long getBlockLimit() {
		return blockLimit;
	}

	
Set maximum number bytes of heap memory to dedicate to caching pack file
data.
 It is strongly recommended to set the block limit to be an integer multiple of the block size. This constraint is not enforced by this method (since it may be called before setBlockSize(int)), but it is enforced by fromConfig(Config). 
Params:
newLimit – 
           maximum number bytes of heap memory to dedicate to caching
           pack file data; must be positive.
Returns:
this/**
	 * Set maximum number bytes of heap memory to dedicate to caching pack file
	 * data.
	 * <p>
	 * It is strongly recommended to set the block limit to be an integer multiple
	 * of the block size. This constraint is not enforced by this method (since
	 * it may be called before {@link #setBlockSize(int)}), but it is enforced by
	 * {@link #fromConfig(Config)}.
	 *
	 * @param newLimit
	 *            maximum number bytes of heap memory to dedicate to caching
	 *            pack file data; must be positive.
	 * @return {@code this}
	 */
	public DfsBlockCacheConfig setBlockLimit(long newLimit) {
		if (newLimit <= 0) {
			throw new IllegalArgumentException(MessageFormat.format(
					JGitText.get().blockLimitNotPositive,
					Long.valueOf(newLimit)));
		}
		blockLimit = newLimit;
		return this;
	}

	
Get size in bytes of a single window mapped or read in from the pack
file.
Returns:
size in bytes of a single window mapped or read in from the pack
        file. Default is 64 KB./**
	 * Get size in bytes of a single window mapped or read in from the pack
	 * file.
	 *
	 * @return size in bytes of a single window mapped or read in from the pack
	 *         file. <b>Default is 64 KB.</b>
	 */
	public int getBlockSize() {
		return blockSize;
	}

	
Set size in bytes of a single window read in from the pack file.
Params:
newSize – 
           size in bytes of a single window read in from the pack file.
           The value must be a power of 2.
Returns:
this/**
	 * Set size in bytes of a single window read in from the pack file.
	 *
	 * @param newSize
	 *            size in bytes of a single window read in from the pack file.
	 *            The value must be a power of 2.
	 * @return {@code this}
	 */
	public DfsBlockCacheConfig setBlockSize(int newSize) {
		int size = Math.max(512, newSize);
		if ((size & (size - 1)) != 0) {
			throw new IllegalArgumentException(
					JGitText.get().blockSizeNotPowerOf2);
		}
		blockSize = size;
		return this;
	}

	
Get the estimated number of threads concurrently accessing the cache.
Returns:
the estimated number of threads concurrently accessing the cache.
        Default is 32./**
	 * Get the estimated number of threads concurrently accessing the cache.
	 *
	 * @return the estimated number of threads concurrently accessing the cache.
	 *         <b>Default is 32.</b>
	 */
	public int getConcurrencyLevel() {
		return concurrencyLevel;
	}

	
Set the estimated number of threads concurrently accessing the cache.
Params:
newConcurrencyLevel – 
           the estimated number of threads concurrently accessing the
           cache.
Returns:
this/**
	 * Set the estimated number of threads concurrently accessing the cache.
	 *
	 * @param newConcurrencyLevel
	 *            the estimated number of threads concurrently accessing the
	 *            cache.
	 * @return {@code this}
	 */
	public DfsBlockCacheConfig setConcurrencyLevel(
			final int newConcurrencyLevel) {
		concurrencyLevel = newConcurrencyLevel;
		return this;
	}

	
Get highest percentage of getBlockLimit() a single pack can occupy while being copied by the pack reuse strategy. 
Returns:
highest percentage of getBlockLimit() a single pack can occupy while being copied by the pack reuse strategy. Default
        is 0.30, or 30%./**
	 * Get highest percentage of {@link #getBlockLimit()} a single pack can
	 * occupy while being copied by the pack reuse strategy.
	 *
	 * @return highest percentage of {@link #getBlockLimit()} a single pack can
	 *         occupy while being copied by the pack reuse strategy. <b>Default
	 *         is 0.30, or 30%</b>.
	 */
	public double getStreamRatio() {
		return streamRatio;
	}

	
Set percentage of cache to occupy with a copied pack.
Params:
ratio – 
           percentage of cache to occupy with a copied pack.
Returns:
this/**
	 * Set percentage of cache to occupy with a copied pack.
	 *
	 * @param ratio
	 *            percentage of cache to occupy with a copied pack.
	 * @return {@code this}
	 */
	public DfsBlockCacheConfig setStreamRatio(double ratio) {
		streamRatio = Math.max(0, Math.min(ratio, 1.0));
		return this;
	}

	
Get the consumer of the object reference lock wait time in milliseconds.
Returns:
consumer of wait time in milliseconds./**
	 * Get the consumer of the object reference lock wait time in milliseconds.
	 *
	 * @return consumer of wait time in milliseconds.
	 */
	public Consumer<Long> getRefLockWaitTimeConsumer() {
		return refLock;
	}

	
Set the consumer for lock wait time.
Params:
c – 
           consumer of wait time in milliseconds.
Returns:
this/**
	 * Set the consumer for lock wait time.
	 *
	 * @param c
	 *            consumer of wait time in milliseconds.
	 * @return {@code this}
	 */
	public DfsBlockCacheConfig setRefLockWaitTimeConsumer(Consumer<Long> c) {
		refLock = c;
		return this;
	}

	
Update properties by setting fields from the configuration.

If a property is not defined in the configuration, then it is left
unmodified.

Enforces certain constraints on the combination of settings in the config,
for example that the block limit is a multiple of the block size.
Params:
rc – 
           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.
	 * <p>
	 * Enforces certain constraints on the combination of settings in the config,
	 * for example that the block limit is a multiple of the block size.
	 *
	 * @param rc
	 *            configuration to read properties from.
	 * @return {@code this}
	 */
	public DfsBlockCacheConfig fromConfig(Config rc) {
		long cfgBlockLimit = rc.getLong(
				CONFIG_CORE_SECTION,
				CONFIG_DFS_SECTION,
				CONFIG_KEY_BLOCK_LIMIT,
				getBlockLimit());
		int cfgBlockSize = rc.getInt(
				CONFIG_CORE_SECTION,
				CONFIG_DFS_SECTION,
				CONFIG_KEY_BLOCK_SIZE,
				getBlockSize());
		if (cfgBlockLimit % cfgBlockSize != 0) {
			throw new IllegalArgumentException(MessageFormat.format(
					JGitText.get().blockLimitNotMultipleOfBlockSize,
					Long.valueOf(cfgBlockLimit),
					Long.valueOf(cfgBlockSize)));
		}

		setBlockLimit(cfgBlockLimit);
		setBlockSize(cfgBlockSize);

		setConcurrencyLevel(rc.getInt(
				CONFIG_CORE_SECTION,
				CONFIG_DFS_SECTION,
				CONFIG_KEY_CONCURRENCY_LEVEL,
				getConcurrencyLevel()));

		String v = rc.getString(
				CONFIG_CORE_SECTION,
				CONFIG_DFS_SECTION,
				CONFIG_KEY_STREAM_RATIO);
		if (v != null) {
			try {
				setStreamRatio(Double.parseDouble(v));
			} catch (NumberFormatException e) {
				throw new IllegalArgumentException(MessageFormat.format(
						JGitText.get().enumValueNotSupported3,
						CONFIG_CORE_SECTION,
						CONFIG_DFS_SECTION,
						CONFIG_KEY_STREAM_RATIO, v));
			}
		}
		return this;
	}
}