FreeRideDisplayRequest.java

/*
 * Copyright (C) 2013 Peng fei Pan <sky@xiaopan.me>
 *
 * Licensed 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 me.xiaopan.sketch.request;

import android.graphics.drawable.Drawable;

import java.util.HashSet;
import java.util.Set;

import me.xiaopan.sketch.SLogType;
import me.xiaopan.sketch.Sketch;
import me.xiaopan.sketch.cache.MemoryCache;
import me.xiaopan.sketch.drawable.RefBitmap;
import me.xiaopan.sketch.drawable.RefBitmapDrawable;
import me.xiaopan.sketch.util.SketchUtils;

/**
 * 支持显示顺风车的请求
 */
public class FreeRideDisplayRequest extends DisplayRequest implements FreeRideManager.DisplayFreeRide {
    private Set<FreeRideManager.DisplayFreeRide> displayFreeRideSet;

    public FreeRideDisplayRequest(Sketch sketch, DisplayInfo requestInfo, DisplayOptions displayOptions,
                                  ViewInfo viewInfo, RequestAndViewBinder requestAndViewBinder,
                                  DisplayListener displayListener, DownloadProgressListener downloadProgressListener) {
        super(sketch, requestInfo, displayOptions, viewInfo, requestAndViewBinder, displayListener, downloadProgressListener);
    }

    @Override
    public String getDisplayFreeRideLog() {
        return String.format("%s@%s", SketchUtils.toHexString(this), getKey());
    }

    @Override
    public String getDisplayFreeRideKey() {
        return getKey();
    }

    /**
     * 可以坐顺风车？条件是内存缓存key一样并且内存缓存可以用，没有单独关闭内存缓存，不解码GIF图片的请求，没有开同步执行，请求执行器可以用
     */
    @Override
    public boolean canByDisplayFreeRide() {
        MemoryCache memoryCache = getConfiguration().getMemoryCache();
        return !memoryCache.isClosed() && !memoryCache.isDisabled()
                && !getOptions().isCacheInMemoryDisabled()
                && !getOptions().isDecodeGifImage()
                && !isSync() && !getConfiguration().getRequestExecutor().isShutdown();
    }

    @Override
    protected void submitRunLoad() {
        // 可以坐顺风车的话，就先尝试坐别人的，坐不上就自己成为顺风车主让别人坐
        if (canByDisplayFreeRide()) {
            FreeRideManager freeRideManager = getConfiguration().getFreeRideManager();
            if (freeRideManager.byDisplayFreeRide(this)) {
                return;
            } else {
                freeRideManager.registerDisplayFreeRideProvider(this);
            }
        }

        super.submitRunLoad();
    }

    @Override
    protected void runLoad() {
        super.runLoad();

        // 由于在submitRunLoad中会将自己注册成为顺风车主，因此一定要保证在这里取消注册
        if (canByDisplayFreeRide()) {
            FreeRideManager freeRideManager = getConfiguration().getFreeRideManager();
            freeRideManager.unregisterDisplayFreeRideProvider(this);
        }
    }

    @Override
    public synchronized void byDisplayFreeRide(FreeRideManager.DisplayFreeRide request) {
        if (displayFreeRideSet == null) {
            synchronized (this) {
                if (displayFreeRideSet == null) {
                    displayFreeRideSet = new HashSet<>();
                }
            }
        }

        displayFreeRideSet.add(request);
    }

    @Override
    public Set<FreeRideManager.DisplayFreeRide> getDisplayFreeRideSet() {
        return displayFreeRideSet;
    }

    @Override
    public synchronized boolean processDisplayFreeRide() {
        MemoryCache memoryCache = getConfiguration().getMemoryCache();
        RefBitmap cachedRefBitmap = memoryCache.get(getMemoryCacheKey());
        if (cachedRefBitmap != null && cachedRefBitmap.isRecycled()) {
            memoryCache.remove(getMemoryCacheKey());
            if (SLogType.REQUEST.isEnabled()) {
                printLogE("memory cache drawable recycled", "processFreeRideRequests", "bitmap=" + cachedRefBitmap.getInfo());
            }
            cachedRefBitmap = null;
        }

        if (cachedRefBitmap != null) {
            // 立马标记等待使用，防止被挤出去回收掉
            cachedRefBitmap.setIsWaitingUse(getLogName() + ":waitingUse:fromMemory", true);

            Drawable drawable = new RefBitmapDrawable(cachedRefBitmap);
            displayResult = new DisplayResult(drawable, ImageFrom.MEMORY_CACHE, cachedRefBitmap.getAttrs());
            displayCompleted();
            return true;
        } else {
            submitRunLoad();
            return false;
        }
    }
}