Implement edge cache for feed

Author: veqtor

conseilUtil.js

@@ -136,11 +136,12 @@ const getArtisticOutputForAddress = async (address) => {
     return objectInfo
 }
 
-const getArtisticUniverse = async (offset) => {
+const getArtisticUniverse = async (max_time) => {
     let mintOperationQuery = conseiljs.ConseilQueryBuilder.blankQuery();
     mintOperationQuery = conseiljs.ConseilQueryBuilder.addFields(mintOperationQuery, 'operation_group_hash');
     mintOperationQuery = conseiljs.ConseilQueryBuilder.addPredicate(mintOperationQuery, 'kind', conseiljs.ConseilOperator.EQ, ['transaction'])
     mintOperationQuery = conseiljs.ConseilQueryBuilder.addPredicate(mintOperationQuery, 'timestamp', conseiljs.ConseilOperator.AFTER, [1612240919000]) // 2021 Feb 1
+    mintOperationQuery = conseiljs.ConseilQueryBuilder.addPredicate(mintOperationQuery, 'timestamp', conseiljs.ConseilOperator.BEFORE, [max_time]) // quantized time (1min)
     mintOperationQuery = conseiljs.ConseilQueryBuilder.addPredicate(mintOperationQuery, 'status', conseiljs.ConseilOperator.EQ, ['applied'])
     mintOperationQuery = conseiljs.ConseilQueryBuilder.addPredicate(mintOperationQuery, 'destination', conseiljs.ConseilOperator.EQ, [mainnet.protocol])
     mintOperationQuery = conseiljs.ConseilQueryBuilder.addPredicate(mintOperationQuery, 'parameters_entrypoints', conseiljs.ConseilOperator.EQ, ['mint_OBJKT'])

index.js

@@ -127,8 +127,18 @@ const filterTz = (data, tz) => _.filter(data, { tz: tz })
 
 const test = async () => console.log(desc(await getObjkts()))
 
-const getFeed = async (counter, res) => {
-    var arr = await conseilUtil.getArtisticUniverse(0)
+const customFloor = function(value, roundTo) {
+    return Math.floor(value / roundTo) * roundTo;
+}
+
+const ONE_MINUTE_MILLIS = 60 * 1000
+
+
+const getFeed = async (counter, max_time, res) => {
+    const now_time = Date.now()
+    const immutable = (typeof max_time !== 'undefined') && (max_time < now_time)
+    max_time = (typeof max_time !== 'undefined') ?  max_time : customFloor(now_time, ONE_MINUTE_MILLIS)
+    var arr = await conseilUtil.getArtisticUniverse(max_time)
     var feed = offset(desc(arr), counter)
     console.log(feed)
     feed = await feed.map(async e => {
@@ -138,11 +148,18 @@ const getFeed = async (counter, res) => {
         return e
     })
     //console.log(feed)
-
+    var cache_time
+    if (immutable) {
+        cache_time = 60*10
+    }
+    else {
+        cache_time = (int)(((max_time + ONE_MINUTE_MILLIS) - now_time) / 1000)
+    }
     var promise = Promise.all(feed.map(e => e))
     promise.then(async (results) => {
         var aux_arr = results.map(e => e)
-
+        
+        res.set('Cache-Control', `public, max-age=${cache_time}`)
         //console.log(aux_arr)
         res.json({ result: aux_arr })
     })
@@ -247,8 +264,10 @@ const app = express()
 app.use(express.json())
 app.use(cors({ origin: '*' }))
 
-app.post('/feed', async (req, res) => {
-    await getFeed(req.body.counter, res)
+app.get('/feed', async (req, res) => {
+    var counter = req.query.counter
+    var max_time = req.query.hasOwnProperty('time') ? customFloor(req.query.time, ONE_MINUTE_MILLIS) : null
+    await getFeed(counter, max_time, res)
 })
 
 app.post('/tz', async (req, res) => {