Gcp/Firebase/Firestore/cacheモジュール

functionsのサンプル

• id別にfirestoreへキャッシュする
• cache保持時間を設定できるように

functions/index.js

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
exports.setCache = functions
  .region('asia-northeast1')
  .https.onRequest((request, response) => {
    var id = request.query['id'];
    var data = request.query['data'];
    const cache = require('./cache.js');
    cache.registerCallback(onCacheResponse);
    cache.setCache(admin, data, id);
    function onCacheResponse(data) {
       response.send("data=" + data);
    }
});

exports.getCache = functions
  .region('asia-northeast1')
  .https.onRequest((request, response) => {
    var id = request.query['id'];
    var data = request.query['data'];
    var cachelifesec = 0;
    if (request.query['cachelifesec'] != null) {
      cachelifesec = parseInt(request.query['cachelifesec']);
    }
    const cache = require('./cache.js');
    cache.registerCallback(onCacheResponse);
    console.log('cachelifesec=' + cachelifesec);
    cache.getCache(admin, id, cachelifesec);
    function onCacheResponse(data) {
       response.send("data=" + data);
    }
});

functions/cache.js

/*
Cache設定例
    const cache = require('./cache.js');
    cache.registerCallback(onCacheResponse);
    cache.setCache(admin, data, id);
    function onCacheResponse(data) {
       response.send("data=" + data);
    }
Cache取得例
    const cache = require('./cache.js');
    cache.registerCallback(onCacheResponse);
    console.log('cachelifesec=' + cachelifesec);
    cache.getCache(admin, id, cachelifesec);
    function onCacheResponse(data) {
       response.send("data=" + data);
    }
*/

var mCallback;
exports.registerCallback = function(callback) {
    mCallback = callback;
}
exports.setCache = function(admin, data, id) {
var date = new Date() ;
var unixtimems = date.getTime() ;
var unixtime = Math.floor( unixtimems / 1000 ) ;
console.log('unixtime=' + unixtime);
  const cache = {
    id: id,
    data: data,
    unixtime: unixtime,
  };
  admin.firestore().collection('caches')
    .doc(id).set(cache)
    .then((snapshot) =>
  {
    mCallback(data);
  });
}
exports.getCache = function(admin, id, cachelifesec) {
    var date = new Date() ;
    var unixtimems = date.getTime() ;
    var unixtime = Math.floor( unixtimems / 1000 ) ;
    console.log('unixtime=' + unixtime);
    var unixtimecachelifesec = unixtime - cachelifesec;
    console.log('cachelifesec=' + cachelifesec);
    console.log('unixtimecachelifesec=' +unixtimecachelifesec);
  admin.firestore().collection('caches')
    .where('id', '==', id)
    .where('unixtime', '>', unixtimecachelifesec)
    .limit(1)
    .get()
    .then((snapshot) =>
  {
    var caches = snapshot.docs.map(x => x.data());
    for (let i = 0; i < caches.length; i++) {
       console.log("ret data=" + caches[i].data);
       mCallback(caches[i].data);
       return;
    }
    mCallback("");
  });
}

httpアクセスで確認

10秒でcacheが切れるサンプルurl

// cache設定
ttps://asia-northeast1-ほげほげ.cloudfunctions.net/setCache?id=hogeid&data=dada1
// cache取得
ttps://asia-northeast1-ほげほげ.cloudfunctions.net/getCache?id=hogeid&cachelifesec=10

cacheはid別にfirestoreに格納される。