WiP: feat(xen-api/getCachedRecord): getRecord + cache + events

Fixes #5088

packages/xen-api/src/index.js

@@ -1,14 +1,25 @@
 import assert from 'assert'
 import dns from 'dns'
+import httpRequest from 'http-request-plus'
 import kindOf from 'kindof'
 import ms from 'ms'
-import httpRequest from 'http-request-plus'
+import pCatch from 'promise-toolbox/catch'
 import { coalesceCalls } from '@vates/coalesce-calls'
 import { Collection } from 'xo-collection'
 import { EventEmitter } from 'events'
 import { map, noop, omit } from 'lodash'
-import { cancelable, defer, fromCallback, fromEvents, ignoreErrors, pDelay, pRetry, pTimeout } from 'promise-toolbox'
 import { limitConcurrency } from 'limit-concurrency-decorator'
+import {
+  cancelable,
+  CancelToken,
+  defer,
+  fromCallback,
+  fromEvents,
+  ignoreErrors,
+  pDelay,
+  pRetry,
+  pTimeout,
+} from 'promise-toolbox'
 
 import autoTransport from './transports/auto'
 import debug from './_debug'
@@ -132,6 +143,7 @@ export class Xapi extends EventEmitter {
     this._lastEventFetchedTimestamp = undefined
 
     this._debounce = opts.debounce ?? 200
+    this._cacheAllRecords = opts.watchEvents !== 'lazy'
     this._objects = new Collection()
     this._objectsByRef = { __proto__: null }
     this._objectsFetched = new Promise(resolve => {
@@ -284,7 +296,13 @@ export class Xapi extends EventEmitter {
   }
 
   async getRecord(type, ref) {
-    return this._wrapRecord(type, ref, await this._roCall(`${type}.get_record`, [ref]))
+    const record = this._wrapRecord(type, ref, await this._roCall(`${type}.get_record`, [ref]))
+    const records = this._objectsByRef
+    if (records !== undefined) {
+      records[ref] = record
+      this._objects[record.$id] = record
+    }
+    return record
   }
 
   async getRecordByUuid(type, uuid) {
@@ -590,10 +608,29 @@ export class Xapi extends EventEmitter {
     return taskRef
   }
 
+  async getCachedRecord(type, ref) {
+    const records = this._objectsByRef
+    let record = records[ref]
+    if (record !== undefined) {
+      return record
+    }
+
+    this._watchType(type)
+
+    record = await pCatch.call(this.getRecord(type, ref), { code: 'HANDLE_INVALID' }, noop)
+    records[ref] = record
+
+    return record
+  }
+
   // Nice getter which returns the object for a given $id (internal to
   // this lib), UUID (unique identifier that some objects have) or
   // opaque reference (internal to XAPI).
   getObject(idOrUuidOrRef, defaultValue) {
+    if (!this._cacheAllRecords) {
+      throw new Error('disabled')
+    }
+
     if (typeof idOrUuidOrRef === 'object') {
       idOrUuidOrRef = idOrUuidOrRef.$id
     }
@@ -610,6 +647,10 @@ export class Xapi extends EventEmitter {
   // Returns the object for a given opaque reference (internal to
   // XAPI).
   getObjectByRef(ref, defaultValue) {
+    if (!this._cacheAllRecords) {
+      throw new Error('disabled')
+    }
+
     const object = this._objectsByRef[ref]
 
     if (object !== undefined) return object
@@ -622,6 +663,10 @@ export class Xapi extends EventEmitter {
   // Returns the object for a given UUID (unique identifier that some
   // objects have).
   getObjectByUuid(uuid, defaultValue) {
+    if (!this._cacheAllRecords) {
+      throw new Error('disabled')
+    }
+
     // Objects ids are already UUIDs if they have one.
     const object = this._objects.all[uuid]
 
@@ -666,10 +711,10 @@ export class Xapi extends EventEmitter {
   // Private
   // ===========================================================================
 
-  async _call(method, args, timeout = this._callTimeout(method, args)) {
+  async _call(method, args, { cancelToken = CancelToken.none, timeout = this._callTimeout(method, args) } = {}) {
     const startTime = Date.now()
     try {
-      const result = await pTimeout.call(this._addSyncStackTrace(this._transport(method, args)), timeout)
+      const result = await pTimeout.call(this._addSyncStackTrace(this._transport(method, args, cancelToken)), timeout)
       debug('%s: %s(...) [%s] ==> %s', this._humanId, method, ms(Date.now() - startTime), kindOf(result))
       return result
     } catch (error) {
@@ -732,7 +777,7 @@ export class Xapi extends EventEmitter {
       this._status !== DISCONNECTED && error?.code === 'SESSION_INVALID' && this._auth.password !== undefined,
     onRetry: () => this._sessionOpen(),
   }
-  async _sessionCall(method, args, timeout) {
+  async _sessionCall(method, args, opts) {
     if (method.startsWith('session.')) {
       return Promise.reject(new Error('session.*() methods are disabled from this interface'))
     }
@@ -747,7 +792,7 @@ export class Xapi extends EventEmitter {
           newArgs.push.apply(newArgs, args)
         }
 
-        return this._call(method, newArgs, timeout)
+        return this._call(method, newArgs, opts)
       }, this._sessionCallRetryOptions)
     } catch (error) {
       if (error?.code === 'SESSION_INVALID') {
@@ -1031,8 +1076,18 @@ export class Xapi extends EventEmitter {
   }
 
   // read-only call, automatically retry in case of connection issues
-  _roCall(method, args) {
-    return pRetry(() => this._sessionCall(method, args), this._roCallRetryOptions)
+  _roCall(...args) {
+    return pRetry(() => this._sessionCall(...args), this._roCallRetryOptions)
+  }
+
+  _cancelEventCall = noop
+
+  _watchType(type) {
+    const watchedTypes = this._watchedTypes
+    if (!watchedTypes.includes(type)) {
+      watchedTypes.push(type)
+      this._cancelEventCall()
+    }
   }
 
   _watchEvents = coalesceCalls(this._watchEvents)
@@ -1067,9 +1122,11 @@ export class Xapi extends EventEmitter {
       const types = this._watchedTypes ?? this._types
 
       // initial fetch
-      await this._refreshCachedRecords(types)
-      this._resolveObjectsFetched()
-      this._resolveObjectsFetched = undefined
+      if (this._cacheAllRecords) {
+        await this._refreshCachedRecords(types)
+        this._resolveObjectsFetched()
+        this._resolveObjectsFetched = undefined
+      }
 
       // event loop
       const debounce = this._debounce
@@ -1082,16 +1139,28 @@ export class Xapi extends EventEmitter {
         try {
           // don't use _sessionCall because a session failure should break the
           // loop and trigger a complete refetch
-          result = await this._call(
-            'event.from',
-            [
-              this._sessionId,
-              types,
-              fromToken,
-              EVENT_TIMEOUT + 0.1, // must be float for XML-RPC transport
-            ],
-            EVENT_TIMEOUT * 1e3 * 1.1
+          result = await pRetry(
+            () => {
+              const source = CancelToken.source()
+              this._cancelEventCall = source.cancel
+
+              return this._call(
+                'event.from',
+                [
+                  this._sessionId,
+                  types,
+                  fromToken,
+                  EVENT_TIMEOUT + 0.1, // must be float for XML-RPC transport
+                ],
+                {
+                  cancelToken: source.token,
+                  timeout: EVENT_TIMEOUT * 1e3 * 1.1,
+                }
+              )
+            },
+            { when: CancelToken.isCancelToken }
           )
+
           this._lastEventFetchedTimestamp = Date.now()
           this._watchEventsError = undefined
           this.emit('eventFetchingSuccess')
@@ -1151,7 +1220,17 @@ export class Xapi extends EventEmitter {
 
       try {
         await this._connected
-        this._processEvents(await this._roCall('event.next', undefined, EVENT_TIMEOUT * 1e3))
+        this._processEvents(
+          await pRetry(
+            () => {
+              const source = CancelToken.source()
+              this._cancelEventCall = source.cancel
+
+              return this._roCall('event.next', undefined, { cancelToken: source.token, timeout: EVENT_TIMEOUT * 1e3 })
+            },
+            { when: CancelToken.isCancelToken }
+          )
+        )
       } catch (error) {
         if (error?.code === 'EVENTS_LOST') {
           await ignoreErrors.call(this._sessionCall('event.unregister', [types]))
@@ -1219,20 +1298,29 @@ export class Xapi extends EventEmitter {
           addMethods(proto)
         }
       })(xapi)
+      const disabledGetter = this._cacheAllRecords
+        ? undefined
+        : () => {
+            throw new Error('disabled')
+          }
       fields.forEach(field => {
-        props[`set_${field}`] = function (value) {
-          return xapi.setField(this.$type, this.$ref, field, value)
-        }
+        props[`set_${field}`] =
+          disabledGetter ||
+          function (value) {
+            return xapi.setField(this.$type, this.$ref, field, value)
+          }
 
         const $field = (field in RESERVED_FIELDS ? '$$' : '$') + field
 
         const value = data[field]
         if (Array.isArray(value)) {
           if (value.length === 0 || Ref.is(value[0])) {
-            getters[$field] = function () {
-              const value = this[field]
-              return value.length === 0 ? value : value.map(getObjectByRef)
-            }
+            getters[$field] =
+              disabledGetter ||
+              function () {
+                const value = this[field]
+                return value.length === 0 ? value : value.map(getObjectByRef)
+              }
           }
 
           props[`add_${field}`] = function (value) {
@@ -1242,23 +1330,27 @@ export class Xapi extends EventEmitter {
             return xapi.call(`${type}.remove_${field}`, this.$ref, value).then(noop)
           }
         } else if (value !== null && typeof value === 'object') {
-          getters[$field] = function () {
-            const value = this[field]
-            const result = {}
-            getKeys(value).forEach(key => {
-              result[key] = xapi._objectsByRef[value[key]]
-            })
-            return result
-          }
+          getters[$field] =
+            disabledGetter ||
+            function () {
+              const value = this[field]
+              const result = {}
+              getKeys(value).forEach(key => {
+                result[key] = xapi._objectsByRef[value[key]]
+              })
+              return result
+            }
           props[`update_${field}`] = function (entries, value) {
             return typeof entries === 'string'
               ? xapi.setFieldEntry(this.$type, this.$ref, field, entries, value)
               : xapi.setFieldEntries(this.$type, this.$ref, field, entries)
           }
         } else if (Ref.is(value)) {
-          getters[$field] = function () {
-            return xapi._objectsByRef[this[field]]
-          }
+          getters[$field] =
+            disabledGetter ||
+            function () {
+              return xapi._objectsByRef[this[field]]
+            }
         }
       })
       const descriptors = {}

packages/xen-api/src/transports/auto.js

@@ -14,14 +14,14 @@ export default opts => {
     const current = factories[i++](opts)
     if (i < length) {
       const currentI = i
-      call = (method, args) =>
-        current(method, args).catch(error => {
+      call = (...args) =>
+        current(...args).catch(error => {
           if (error instanceof UnsupportedTransport) {
             if (currentI === i) {
               // not changed yet
               create()
             }
-            return call(method, args)
+            return call(...args)
           }
 
           throw error
@@ -32,5 +32,5 @@ export default opts => {
   }
   create()
 
-  return (method, args) => call(method, args)
+  return (...args) => call(...args)
 }

packages/xen-api/src/transports/json-rpc.js

@@ -12,9 +12,9 @@ export default ({ secureOptions, url, httpProxy }) => {
   if (httpProxy !== undefined) {
     agent = new ProxyAgent(httpProxy)
   }
-  return (method, args) =>
+  return (method, args, cancelToken) =>
     httpRequestPlus
-      .post(url, {
+      .post(cancelToken, url, {
         ...secureOptions,
         body: format.request(0, method, args),
         headers: {

packages/xen-api/src/transports/xml-rpc-json.js

@@ -86,5 +86,5 @@ export default ({ secureOptions, url: { hostname, port, protocol }, httpProxy })
   })
   const call = promisify(client.methodCall, client)
 
-  return (method, args) => call(method, prepareXmlRpcParams(args)).then(parseResult, logError)
+  return (method, args, cancelToken) => call(method, prepareXmlRpcParams(args), cancelToken).then(parseResult, logError)
 }

packages/xen-api/src/transports/xml-rpc.js

@@ -45,5 +45,9 @@ export default ({ secureOptions, url: { hostname, port, protocol, httpProxy } })
   })
   const call = promisify(client.methodCall, client)
 
-  return (method, args) => call(method, prepareXmlRpcParams(args)).then(parseResult, logError)
+  return (method, args, cancelToken) =>
+    new Promise((resolve, reject) => {
+      call(method, prepareXmlRpcParams(args), cancelToken).then(resolve, reject)
+      cancelToken.addHandler(reject)
+    }).then(parseResult, logError)
 }