refactor: convert dht API to async/await (#1156)

Author: Alan Shaw

src/dht/find-peer.js

@@ -0,0 +1,37 @@
+'use strict'
+
+const PeerId = require('peer-id')
+const PeerInfo = require('peer-info')
+const multiaddr = require('multiaddr')
+const ndjson = require('iterable-ndjson')
+const configure = require('../lib/configure')
+const toIterable = require('../lib/stream-to-iterable')
+
+module.exports = configure(({ ky }) => {
+  return (peerId, options) => (async function * () {
+    options = options || {}
+
+    const searchParams = new URLSearchParams(options.searchParams)
+    searchParams.set('arg', `${peerId}`)
+    if (options.verbose != null) searchParams.set('verbose', options.verbose)
+
+    const res = await ky.get('dht/findpeer', {
+      timeout: options.timeout,
+      signal: options.signal,
+      headers: options.headers,
+      searchParams
+    })
+
+    for await (const message of ndjson(toIterable(res.body))) {
+      // 2 = FinalPeer
+      // https://github.com/libp2p/go-libp2p-core/blob/6e566d10f4a5447317a66d64c7459954b969bdab/routing/query.go#L18
+      if (message.Type === 2 && message.Responses) {
+        for (const { ID, Addrs } of message.Responses) {
+          const peerInfo = new PeerInfo(PeerId.createFromB58String(ID))
+          if (Addrs) Addrs.forEach(a => peerInfo.multiaddrs.add(multiaddr(a)))
+          yield peerInfo
+        }
+      }
+    }
+  })()
+})

src/dht/find-provs.js

@@ -0,0 +1,38 @@
+'use strict'
+
+const PeerId = require('peer-id')
+const PeerInfo = require('peer-info')
+const multiaddr = require('multiaddr')
+const ndjson = require('iterable-ndjson')
+const configure = require('../lib/configure')
+const toIterable = require('../lib/stream-to-iterable')
+
+module.exports = configure(({ ky }) => {
+  return (cid, options) => (async function * () {
+    options = options || {}
+
+    const searchParams = new URLSearchParams(options.searchParams)
+    searchParams.set('arg', `${cid}`)
+    if (options.numProviders) searchParams.set('num-providers', options.numProviders)
+    if (options.verbose != null) searchParams.set('verbose', options.verbose)
+
+    const res = await ky.get('dht/findprovs', {
+      timeout: options.timeout,
+      signal: options.signal,
+      headers: options.headers,
+      searchParams
+    })
+
+    for await (const message of ndjson(toIterable(res.body))) {
+      // 4 = Provider
+      // https://github.com/libp2p/go-libp2p-core/blob/6e566d10f4a5447317a66d64c7459954b969bdab/routing/query.go#L20
+      if (message.Type === 4 && message.Responses) {
+        for (const { ID, Addrs } of message.Responses) {
+          const peerInfo = new PeerInfo(PeerId.createFromB58String(ID))
+          if (Addrs) Addrs.forEach(a => peerInfo.multiaddrs.add(multiaddr(a)))
+          yield peerInfo
+        }
+      }
+    }
+  })()
+})

src/dht/findpeer.js

@@ -1,48 +1,30 @@
 'use strict'
 
-const promisify = require('promisify-es6')
+const ndjson = require('iterable-ndjson')
+const configure = require('../lib/configure')
+const toIterable = require('../lib/stream-to-iterable')
 
-module.exports = (send) => {
-  return promisify((key, opts, callback) => {
-    if (typeof opts === 'function' && !callback) {
-      callback = opts
-      opts = {}
-    }
-
-    // opts is the real callback --
-    // 'callback' is being injected by promisify
-    if (typeof opts === 'function' && typeof callback === 'function') {
-      callback = opts
-      opts = {}
-    }
+module.exports = configure(({ ky }) => {
+  return (key, options) => (async function * () {
+    options = options || {}
 
-    function handleResult (done, err, res) {
-      if (err) {
-        return done(err)
-      }
-      if (!res) {
-        return done(new Error('empty response'))
-      }
-      if (res.length === 0) {
-        return done(new Error('no value returned for key'))
-      }
+    const searchParams = new URLSearchParams(options.searchParams)
+    searchParams.set('arg', `${key}`)
+    if (options.verbose != null) searchParams.set('verbose', options.verbose)
 
-      // Inconsistent return values in the browser vs node
-      if (Array.isArray(res)) {
-        res = res[0]
-      }
+    const res = await ky.get('dht/get', {
+      timeout: options.timeout,
+      signal: options.signal,
+      headers: options.headers,
+      searchParams
+    })
 
-      if (res.Type === 5) {
-        done(null, res.Extra)
-      } else {
-        done(new Error('key was not found (type 6)'))
+    for await (const message of ndjson(toIterable(res.body))) {
+      // 5 = Value
+      // https://github.com/libp2p/go-libp2p-core/blob/6e566d10f4a5447317a66d64c7459954b969bdab/routing/query.go#L21
+      if (message.Type === 5) {
+        yield message.Extra
       }
     }
-
-    send({
-      path: 'dht/get',
-      args: key,
-      qs: opts
-    }, handleResult.bind(null, callback))
-  })
-}
+  })()
+})

src/dht/findprovs.js

@@ -1,17 +1,30 @@
 'use strict'
 
-const moduleConfig = require('../utils/module-config')
+const callbackify = require('callbackify')
+const errCode = require('err-code')
+const { collectify } = require('../lib/converters')
 
-module.exports = (arg) => {
-  const send = moduleConfig(arg)
+module.exports = config => {
+  const get = require('./get')(config)
+  const findPeer = require('./find-peer')(config)
 
   return {
-    get: require('./get')(send),
-    put: require('./put')(send),
-    findProvs: require('./findprovs')(send),
-    findPeer: require('./findpeer')(send),
-    provide: require('./provide')(send),
+    get: callbackify.variadic(async (key, options) => {
+      for await (const value of get(key, options)) {
+        return value
+      }
+      throw errCode(new Error('value not found'), 'ERR_TYPE_5_NOT_FOUND')
+    }),
+    put: callbackify.variadic(collectify(require('./put')(config))),
+    findProvs: callbackify.variadic(collectify(require('./find-provs')(config))),
+    findPeer: callbackify.variadic(async (peerId, options) => {
+      for await (const peerInfo of findPeer(peerId, options)) {
+        return peerInfo
+      }
+      throw errCode(new Error('final peer not found'), 'ERR_TYPE_2_NOT_FOUND')
+    }),
+    provide: callbackify.variadic(collectify(require('./provide')(config))),
     // find closest peerId to given peerId
-    query: require('./query')(send)
+    query: callbackify.variadic(collectify(require('./query')(config)))
   }
 }

src/dht/get.js

@@ -1,37 +1,40 @@
 'use strict'
 
-const promisify = require('promisify-es6')
-const CID = require('cids')
+const PeerId = require('peer-id')
+const PeerInfo = require('peer-info')
+const multiaddr = require('multiaddr')
+const ndjson = require('iterable-ndjson')
+const configure = require('../lib/configure')
+const toIterable = require('../lib/stream-to-iterable')
+const toCamel = require('../lib/object-to-camel')
 
-module.exports = (send) => {
-  return promisify((cids, opts, callback) => {
-    if (typeof opts === 'function' && !callback) {
-      callback = opts
-      opts = {}
-    }
+module.exports = configure(({ ky }) => {
+  return (cids, options) => (async function * () {
+    cids = Array.isArray(cids) ? cids : [cids]
+    options = options || {}
 
-    // opts is the real callback --
-    // 'callback' is being injected by promisify
-    if (typeof opts === 'function' && typeof callback === 'function') {
-      callback = opts
-      opts = {}
-    }
+    const searchParams = new URLSearchParams(options.searchParams)
+    cids.forEach(cid => searchParams.append('arg', `${cid}`))
+    if (options.recursive != null) searchParams.set('recursive', options.recursive)
+    if (options.verbose != null) searchParams.set('verbose', options.verbose)
 
-    if (!Array.isArray(cids)) {
-      cids = [cids]
-    }
+    const res = await ky.get('dht/provide', {
+      timeout: options.timeout,
+      signal: options.signal,
+      headers: options.headers,
+      searchParams
+    })
 
-    // Validate CID(s) and serialize
-    try {
-      cids = cids.map(cid => new CID(cid).toBaseEncodedString('base58btc'))
-    } catch (err) {
-      return callback(err)
+    for await (let message of ndjson(toIterable(res.body))) {
+      message = toCamel(message)
+      if (message.responses) {
+        message.responses = message.responses.map(({ ID, Addrs }) => {
+          const peerInfo = new PeerInfo(PeerId.createFromB58String(ID))
+          if (Addrs) Addrs.forEach(a => peerInfo.multiaddrs.add(multiaddr(a)))
+          return peerInfo
+        })
+      }
+      yield message
     }
-
-    send({
-      path: 'dht/provide',
-      args: cids,
-      qs: opts
-    }, callback)
-  })
-}
+  })()
+})