优化托管于阿里云函数计算的Node.js应用 - 以Parse为例

'use strict';
varOSS=require('ali-oss').Wrapper;
constDEFAULT_OSS_REGION="oss-cn-hangzhou";
functionrequiredOrFromEnvironment(options, key, env) {
options[key] =options[key] ||process.env[env];
if (!options[key]) {
throw`OSSAdapter requires option '${key}' or env. variable ${env}`;
    }
returnoptions;
}
functionfromEnvironmentOrDefault(options, key, env, defaultValue) {
options[key] =options[key] ||process.env[env] ||defaultValue;
returnoptions;
}
functionoptionsFromArguments(args) {
letoptions= {};
letaccessKeyOrOptions=args[0];
if (typeofaccessKeyOrOptions=='string') {
options.accessKey=accessKeyOrOptions;
options.secretKey=args[1];
options.bucket=args[2];
letotherOptions=args[3];
if (otherOptions) {
options.bucketPrefix=otherOptions.bucketPrefix;
options.region=otherOptions.region;
options.directAccess=otherOptions.directAccess;
options.baseUrl=otherOptions.baseUrl;
options.baseUrlDirect=otherOptions.baseUrlDirect;
        }
    } else {
options=accessKeyOrOptions|| {};
    }
options=requiredOrFromEnvironment(options, 'accessKey', 'OSS_ACCESS_KEY');
options=requiredOrFromEnvironment(options, 'secretKey', 'OSS_SECRET_KEY');
options=requiredOrFromEnvironment(options, 'bucket', 'OSS_BUCKET');
options=fromEnvironmentOrDefault(options, 'bucketPrefix', 'OSS_BUCKET_PREFIX', '');
options=fromEnvironmentOrDefault(options, 'region', 'OSS_REGION', DEFAULT_OSS_REGION);
options=fromEnvironmentOrDefault(options, 'directAccess', 'OSS_DIRECT_ACCESS', false);
options=fromEnvironmentOrDefault(options, 'baseUrl', 'OSS_BASE_URL', null);
options=fromEnvironmentOrDefault(options, 'baseUrlDirect', 'OSS_BASE_URL_DIRECT', false);
returnoptions;
}
functionOSSAdapter() {
varoptions=optionsFromArguments(arguments);
this._region=options.region;
this._bucket=options.bucket;
this._bucketPrefix=options.bucketPrefix;
this._directAccess=options.directAccess;
this._baseUrl=options.baseUrl;
this._baseUrlDirect=options.baseUrlDirect;
letossOptions= {
accessKeyId: options.accessKey, accessKeySecret: options.secretKey, bucket: this._bucket, region: this._region    };
this._ossClient=newOSS(ossOptions);
this._ossClient.listBuckets().then((val) => {
varbucket=val.buckets.filter((bucket) => {
returnbucket.name===this._bucket        }).pop();
this._hasBucket=!!bucket;
    });
}
OSSAdapter.prototype.createBucket=function () {
if (this._hasBucket) {
returnPromise.resolve();
    } else {
returnthis._ossClient.putBucket(this._bucket, this._region).then(() => {
this._hasBucket=true;
if (this._directAccess) {
returnthis._ossClient.putBucketACL(this._bucket, this._region, 'public-read');
            }
returnPromise.resolve();
        }).then(() => {
returnthis._ossClient.useBucket(this._bucket, this._region);
        });
    }
};
OSSAdapter.prototype.createFile=function (filename, data, contentType) {
letoptions= {};
if (contentType) {
options.headers= {'Content-Type': contentType}
    }
returnthis.createBucket().then(() => {
returnthis._ossClient.put(this._bucketPrefix+filename, newBuffer(data), options);
    });
};
OSSAdapter.prototype.deleteFile=function (filename) {
returnthis.createBucket().then(() => {
returnthis._ossClient.delete(this._bucketPrefix+filename);
    });
};
OSSAdapter.prototype.getFileData=function (filename) {
returnthis.createBucket().then(() => {
returnthis._ossClient.get(this._bucketPrefix+filename).then((val) => {
returnPromise.resolve(val.content);
        }).catch((err) => {
returnPromise.reject(err);
        });
    });
};
OSSAdapter.prototype.getFileLocation=function (config, filename) {
varurl=this._ossClient.signatureUrl(this._bucketPrefix+filename);
url=url.replace(/^http:/, "https:");
returnurl;
};
module.exports=OSSAdapter;
module.exports.default=OSSAdapter;