游戏内存优化那点事

/**
 * 资源管理
 * @see ResManager.ts 
 */

import PromiseUtil from "https://zhuanlan.zhihu.com/Utils/PromiseUtil";

export class ResManager{

    private static instance: ResManager;
    private resMap: Map<string, cc.Asset>=new Map()

    public static getInstance(): ResManager{
        if (this.instance==null){
            this.instance=new ResManager();
        }
        return this.instance;
    }


    /**
     * 加载资源
     * @param path 资源绝对路径
     * @returns 
     */
    public loadRes<T extends cc.Asset>(path, type?){
        return new Promise<T>((resolve, reject)=>{
            if (type){
                cc.resources.load(path, type, (error: Error, asset: T)=>{
                    if (error){
                        cc.error(error)
                        reject();
                    }
                    if (!asset) reject();
                    asset.addRef();
                    // cc.log('ResMgr==load==>', path, asset.refCount);
                    if (!this.resMap.get(path)) this.resMap.set(path, asset);
                    resolve(asset)
                });
            }else{
                cc.resources.load(path, (error: Error, asset: T)=>{
                    if (error){
                        cc.error(error)
                        reject();
                    }
                    if (!asset) reject();
                    asset.addRef();
                    // cc.log('ResMgr==load==>', path, asset.refCount);
                    if (!this.resMap.get(path)) this.resMap.set(path, asset);
                    resolve(asset)
                });
            }
        });
    }

    /**
     * 卸载资源(引用计数减1)
     * @param path 资源绝对路径
     */
    public releaseRes(path: string){
        let asset=this.resMap.get(path)
        if (asset && asset.refCount > 0){
            asset.decRef();
            // cc.log('ResMgr==release==>', path, asset.refCount);
            if (asset.refCount==0){
                this.resMap.delete(path);
            }
        }
    }

    /**
    * 强制卸载资源 
    * @param path 资源绝对路径
    */
    public forceReleaseRes(path: string){
        cc.resources.release(path);
    }

    /**
    * 加载目录资源
    * @param dirPath 
    */
    public loadDir(dirPath: string){
        let infos=cc.resources.getDirWithPath(dirPath);
        infos.map(async (info)=>{
            this.loadRes(info.path);
            await PromiseUtil.wait(0);
        });
    }

    /**
    * 卸载目录资源
    * @param dirPath 目录
    */
    public releaseDir(dirPath: string){
        let infos=cc.resources.getDirWithPath(dirPath);
        infos.map((info)=>{
            this.releaseRes(info.path);
        });
    }

    /**
    * 强制卸载目录资源 
    * @param path 资源绝对路径
    */
    public forceReleaseDir(dirPath: string){
        let infos=cc.resources.getDirWithPath(dirPath);
        infos.map((info)=>{
            this.forceReleaseRes(info.path);
        });
    }
}