andresusandi-storage/GoogleCloudStorage.js

storage utilities for distributed systems

const { Datastore } = require('@google-cloud/datastore');
const { name: packageName } = require('./package.json');
const { v4: uuid } = require('uuid');

class GoogleCloudStorage {
    constructor(name, projectId, keyFilename) {
        this.datastore = new Datastore({ projectId, keyFilename });
        this.name = name;
        this.instanceId = uuid();
        console.log(`${packageName}/${this.constructor.name}: Creating Google Cloud Storage Instance for ${name}, assigning instanceId ${this.instanceId}`);
    }

    async init() {

    }

    async save(key, value) {
        console.log(`${packageName}/${this.constructor.name}: Saving item with key ${key} and value ${JSON.stringify(value)}`);
        await this.datastore.save({
            key: this.datastore.key([this.name, key]),
            data: { value },
        });
    }

    async get(key) {
        console.log(`${packageName}/${this.constructor.name}: Retrieving item with key ${key}`);
        var item = await this.datastore.get(this.datastore.key([this.name, key]));
        if (item[0])
            return(item[0].value)
    }

    async delete(key) {
        console.log(`${packageName}/${this.constructor.name}: Deleting item with key ${key}`);
        await this.datastore.delete(this.datastore.key([this.name, key]));
    }

    async getAllItems() {
        console.log(`${packageName}/${this.constructor.name}: Getting all items`);
        var query = this.datastore
            .createQuery(this.name);
        
        var [entities, info] = await this.datastore.runQuery(query);
        while (info.moreResults !== Datastore.NO_MORE_RESULTS) {
            query = query.start(info.endCursor);
            const [moreEntities, moreInfo] = await this.datastore.runQuery(query);
            entities = entities.concat(moreEntities);
            info = moreInfo;
        }

        for (var i = 0; i < entities.length; i++) {
            entities[i].__key__ = entities[i][this.datastore.KEY];
            delete entities[i][this.datastore.KEY];
        }

        return entities;
    }
}

module.exports = GoogleCloudStorage;