1 files changed, 202 insertions, 0 deletions

diff --git a/server/lib/request-scheduler.js b/server/lib/request-scheduler.js
new file mode 100644
index 000000000..c8bc4af28
--- /dev/null
+++ b/server/lib/request-scheduler.js
@@ -0,0 +1,202 @@
+'use strict'
+
+const eachLimit = require('async/eachLimit')
+
+const constants = require('../initializers/constants')
+const db = require('../initializers/database')
+const logger = require('../helpers/logger')
+const requests = require('../helpers/requests')
+
+module.exports = class RequestScheduler {
+
+  constructor (name) {
+    this.name = name
+
+    this.lastRequestTimestamp = 0
+    this.timer = null
+  }
+
+  activate () {
+    logger.info('Requests scheduler activated.')
+    this.lastRequestTimestamp = Date.now()
+
+    this.timer = setInterval(() => {
+      this.lastRequestTimestamp = Date.now()
+      this.makeRequests()
+    }, constants.REQUESTS_INTERVAL)
+  }
+
+  deactivate () {
+    logger.info('Requests scheduler deactivated.')
+    clearInterval(this.timer)
+    this.timer = null
+  }
+
+  forceSend () {
+    logger.info('Force requests scheduler sending.')
+    this.makeRequests()
+  }
+
+  remainingMilliSeconds () {
+    if (this.timer === null) return -1
+
+    return constants.REQUESTS_INTERVAL - (Date.now() - this.lastRequestTimestamp)
+  }
+
+  // { type, endpoint, data, toIds, transaction }
+  createRequest (options, callback) {
+    const type = options.type
+    const endpoint = options.endpoint
+    const data = options.data
+    const toIds = options.toIds
+    const transaction = options.transaction
+
+    const pods = []
+
+    // If there are no destination pods abort
+    if (toIds.length === 0) return callback(null)
+
+    toIds.forEach(toPod => {
+      pods.push(db.Pod.build({ id: toPod }))
+    })
+
+    const createQuery = {
+      endpoint,
+      request: {
+        type: type,
+        data: data
+      }
+    }
+
+    const dbRequestOptions = {
+      transaction
+    }
+
+    return db.Request.create(createQuery, dbRequestOptions).asCallback((err, request) => {
+      if (err) return callback(err)
+
+      return request.setPods(pods, dbRequestOptions).asCallback(callback)
+    })
+  }
+
+  // ---------------------------------------------------------------------------
+
+  // Make all the requests of the scheduler
+  makeRequests () {
+    // We limit the size of the requests
+    // We don't want to stuck with the same failing requests so we get a random list
+    db.Request.listWithLimitAndRandom(constants.REQUESTS_LIMIT_PODS, constants.REQUESTS_LIMIT_PER_POD, (err, requests) => {
+      if (err) {
+        logger.error('Cannot get the list of requests.', { err: err })
+        return // Abort
+      }
+
+      // If there are no requests, abort
+      if (requests.length === 0) {
+        logger.info('No requests to make.')
+        return
+      }
+
+      // We want to group requests by destinations pod and endpoint
+      const requestsToMakeGrouped = this.buildRequestObjects(requests)
+
+      logger.info('Making requests to friends.')
+
+      const goodPods = []
+      const badPods = []
+
+      eachLimit(Object.keys(requestsToMakeGrouped), constants.REQUESTS_IN_PARALLEL, (hashKey, callbackEach) => {
+        const requestToMake = requestsToMakeGrouped[hashKey]
+        const toPod = requestToMake.toPod
+
+        // Maybe the pod is not our friend anymore so simply remove it
+        if (!toPod) {
+          const requestIdsToDelete = requestToMake.ids
+
+          logger.info('Removing %d requests of unexisting pod %s.', requestIdsToDelete.length, requestToMake.toPod.id)
+          return db.RequestToPod.removePodOf(requestIdsToDelete, requestToMake.toPod.id, callbackEach)
+        }
+
+        this.makeRequest(toPod, requestToMake.endpoint, requestToMake.datas, (success) => {
+          if (success === false) {
+            badPods.push(requestToMake.toPod.id)
+            return callbackEach()
+          }
+
+          logger.debug('Removing requests for pod %s.', requestToMake.toPod.id, { requestsIds: requestToMake.ids })
+          goodPods.push(requestToMake.toPod.id)
+
+          // Remove the pod id of these request ids
+          db.RequestToPod.removePodOf(requestToMake.ids, requestToMake.toPod.id, callbackEach)
+        })
+      }, () => {
+        // All the requests were made, we update the pods score
+        db.Request.updatePodsScore(goodPods, badPods)
+        // Flush requests with no pod
+        db.Request.removeWithEmptyTo(err => {
+          if (err) logger.error('Error when removing requests with no pods.', { error: err })
+        })
+      })
+    })
+  }
+
+  // Make a requests to friends of a certain type
+  makeRequest (toPod, requestEndpoint, requestsToMake, callback) {
+    if (!callback) callback = function () {}
+
+    const params = {
+      toPod: toPod,
+      sign: true, // Prove our identity
+      method: 'POST',
+      path: '/api/' + constants.API_VERSION + '/remote/' + requestEndpoint,
+      data: requestsToMake // Requests we need to make
+    }
+
+    // Make multiple retry requests to all of pods
+    // The function fire some useful callbacks
+    requests.makeSecureRequest(params, (err, res) => {
+      if (err || (res.statusCode !== 200 && res.statusCode !== 201 && res.statusCode !== 204)) {
+        err = err ? err.message : 'Status code not 20x : ' + res.statusCode
+        logger.error('Error sending secure request to %s pod.', toPod.host, { error: err })
+
+        return callback(false)
+      }
+
+      return callback(true)
+    })
+  }
+
+  buildRequestObjects (requests) {
+    const requestsToMakeGrouped = {}
+
+    Object.keys(requests).forEach(toPodId => {
+      requests[toPodId].forEach(data => {
+        const request = data.request
+        const pod = data.pod
+        const hashKey = toPodId + request.endpoint
+
+        if (!requestsToMakeGrouped[hashKey]) {
+          requestsToMakeGrouped[hashKey] = {
+            toPod: pod,
+            endpoint: request.endpoint,
+            ids: [], // request ids, to delete them from the DB in the future
+            datas: [] // requests data,
+          }
+        }
+
+        requestsToMakeGrouped[hashKey].ids.push(request.id)
+        requestsToMakeGrouped[hashKey].datas.push(request.request)
+      })
+    })
+
+    return requestsToMakeGrouped
+  }
+
+  flush (callback) {
+    db.Request.removeAll(err => {
+      if (err) logger.error('Cannot flush the requests.', { error: err })
+
+      return callback(err)
+    })
+  }
+}