WIP

lib/routes.js

@@ -3,6 +3,7 @@
 const BigNumber = require('bignumber.js')
 const logger = require('./logger')
 const configManager = require('./config-manager')
+const db = require('./db')
 
 let mock = false
 
@@ -121,16 +122,15 @@ function poll (req, res) {
     .catch(logger.error)
 }
 
-function trade (req, res) {
+function trade (req, res, next) {
   const tx = req.body
   tx.cryptoAtoms = new BigNumber(tx.cryptoAtoms)
 
   plugins.trade(getDeviceId(req), tx)
-    .then(() => res.status(201).json({}))
-    .catch(err => {
-      logger.error(err)
-      res.status(500).json({err})
-    })
+  .then(() => {
+    updateCachedAction(req, {}, 201)
+    res.status(201).json({})
+  })
 }
 
 function stateChange (req, res) {
@@ -147,20 +147,11 @@ function send (req, res) {
   tx.cryptoAtoms = new BigNumber(tx.cryptoAtoms)
 
   return plugins.sendCoins(getDeviceId(req), tx)
-    .then(status => {
-      res.json({
-        txHash: status && status.txHash,
-        txId: status && status.txId
-      })
-    })
-    .catch(err => {
-      console.log('DEBUG15: %s', err)
-      logger.error(err)
-      res.json({
-        err: err.message,
-        errType: err.name
-      })
-    })
+  .then(status => {
+    const body = {txId: status && status.txId}
+    updateCachedAction(req, body, 200)
+    .then(() => res.json(body))
+  })
 }
 
 function cashOut (req, res) {
@@ -232,8 +223,14 @@ function pair (req, res) {
 
   return pair.pair(token, deviceId)
   .then(valid => {
-    if (valid) return res.status(200).end()
-    return res.status(408).end()
+    updateCachedAction(req, {})
+    if (valid) {
+      updateCachedAction(req, {}, 200)
+      return res.json({})
+    }
+
+    updateCachedAction(req, {}, 408)
+    return res.status(408).json({})
   })
 }
 
@@ -333,6 +330,44 @@ function dispense (req, res) {
   .catch(err => logger.error(err))
 }
 
+function isUniqueViolation (err) {
+  return err.code === '23505'
+}
+
+function cacheAction (req, res, next) {
+  const sql = `insert into idempotents (request_id, device_id, body, status, pending)
+  values ($1, $2, $3, $4, $5)`
+
+  const requestId = req.headers['request-id']
+  const deviceId = getDeviceId(req)
+
+  db.none(sql, [requestId, deviceId, {}, 204, true])
+  .then(() => next())
+  .catch(err => {
+    if (!isUniqueViolation(err)) throw err
+
+    const sql2 = 'select body, status, pending from idempotents where request_id=$1'
+    return db.one(sql2, [requestId])
+    .then(row => {
+      if (row.pending) return res.status(204).end()
+      return res.status(row.status).json(row.body)
+    })
+  })
+}
+
+function cachedActionError (req, err, status) {
+  return updateCachedAction(req, {error: err}, status || 500)
+}
+
+function updateCachedAction (req, body, status) {
+  const sql = 'update idempotents set body=$1, status=$2, pending=$3 where request_id=$4 and device_id=$5'
+
+  const requestId = req.headers['request-id']
+  const deviceId = getDeviceId(req)
+
+  return db.none(sql, [body, status, false, requestId, deviceId])
+}
+
 function init (opts) {
   plugins = opts.plugins
   mock = opts.mock
@@ -341,6 +376,8 @@ function init (opts) {
   const app = opts.app
   const localApp = opts.localApp
 
+  app.post('*', cacheAction)
+
   app.post('/pair', pair)
   app.get('/ca', ca)
 
@@ -363,6 +400,8 @@ function init (opts) {
   app.get('/await_dispense/:txId', authMiddleware, waitForDispense)
   app.post('/dispense', authMiddleware, dispense)
 
+  app.post('*', updateCachedAction)
+
   localApp.get('/pid', (req, res) => {
     const deviceId = req.query.device_id
     const pidRec = pids[deviceId]
@@ -403,11 +442,3 @@ function getDeviceId (req) {
   req.connection.getPeerCertificate().fingerprint) || 'unknown'
 }
 
-function cachedResponse (deviceId, txId, req) {
-  return plugins.cachedResponse(deviceId, txId, req.path, req.method)
-  .then(r => r.body)
-}
-
-function cacheResponse (deviceId, txId, req, body) {
-  return plugins.cacheResponse(deviceId, txId, req.path, req.method, body)
-}

migrations/016-new_cached_requests_table.js

@@ -0,0 +1,20 @@
+var db = require('./db')
+
+exports.up = function (next) {
+  var sql = [
+    'drop table if exists cached_responses',
+    `create table idempotents (
+      request_id text PRIMARY KEY,
+      device_id text NOT NULL,
+      body json NOT NULL,
+      status integer NOT NULL,
+      pending boolean NOT NULL,
+      created timestamptz NOT NULL default now()
+    )`
+  ]
+  db.multi(sql, next)
+}
+
+exports.down = function (next) {
+  next()
+}

package.json

@@ -15,6 +15,7 @@
     "bunyan": "^1.8.1",
     "chalk": "^1.1.3",
     "express": "^4.13.4",
+    "express-limiter": "^1.6.0",
     "helmet": "^2.3.0",
     "inquirer": "^1.0.0",
     "lamassu-bitcoinaverage": "~1.0.0",
@@ -36,6 +37,7 @@
     "node-hkdf-sync": "^1.0.0",
     "node-uuid": "^1.4.2",
     "numeral": "^1.5.3",
+    "on-finished": "^2.3.0",
     "pg": "^4.5.5",
     "pg-promise": "^4.3.3",
     "pify": "^2.3.0",

todo.txt

@@ -109,3 +109,8 @@ options: configure per machine; configure per crypto/fiat
 
 v need to create CA: http://stackoverflow.com/questions/19665863/how-do-i-use-a-self-signed-certificate-for-a-https-node-js-server
 
+--------------------------------
+
+- consistent error handling
+- usage of http status codes (good for got)
+- finish idempotency for all calls