Mailspring/internal_packages/worker-sync/spec/nylas-sync-worker-pool-spec.coffee
Ben Gotow a14a5212ac feat(transactions): Explicit (and faster) database transactions
Summary:
Until now, we've been hiding transactions beneath the surface. When you call persistModel, you're implicitly creating a transaction.
You could explicitly create them with `atomically`..., but there were several critical problems that are fixed in this diff:

- Calling persistModel / unpersistModel within a transaction could cause the DatabaseStore to trigger. This could result in other parts of the app making queries /during/
  the transaction, potentially before the COMMIT occurred and saved the changes. The new, explicit inTransaction syntax holds all changes until after COMMIT and then triggers.

- Calling atomically and then calling persistModel inside that resulted in us having to check whether a transaction was present and was gross.

- Many parts of the code ran extensive logic inside a promise chained within `atomically`:

  BAD:

```
  DatabaseStore.atomically =>
   DatabaseStore.persistModel(draft) =>
     GoMakeANetworkRequestThatReturnsAPromise
```

OVERWHELMINGLY BETTER:

```
  DatabaseStore.inTransaction (t) =>
     t.persistModel(draft)
  .then =>
    GoMakeANetworkRequestThatReturnsAPromise
```

Having explicit transactions also puts us on equal footing with Sequelize and other ORMs. Note that you /have/ to call DatabaseStore.inTransaction (t) =>. There is no other way to access the methods that let you alter the database. :-)

Other changes:
- This diff removes Message.labels and the Message-Labels table. We weren't using Message-level labels anywhere, and the table could grow very large.
- This diff changes the page size during initial sync from 250 => 200 in an effort to make transactions a bit faster.

Test Plan: Run tests!

Reviewers: juan, evan

Reviewed By: juan, evan

Differential Revision: https://phab.nylas.com/D2353
2015-12-17 11:46:05 -08:00

126 lines
5.1 KiB
CoffeeScript

_ = require 'underscore'
fs = require 'fs'
path = require 'path'
{NylasAPI,
Thread,
DatabaseStore,
DatabaseTransaction,
Actions} = require 'nylas-exports'
NylasSyncWorkerPool = require '../lib/nylas-sync-worker-pool'
fixturesPath = path.resolve(__dirname, 'fixtures')
describe "NylasSyncWorkerPool", ->
describe "handleDeltas", ->
beforeEach ->
@sampleDeltas = JSON.parse(fs.readFileSync("#{fixturesPath}/sample.json"))
@sampleClustered = JSON.parse(fs.readFileSync("#{fixturesPath}/sample-clustered.json"))
it "should immediately fire the received raw deltas event", ->
spyOn(Actions, 'longPollReceivedRawDeltas')
spyOn(NylasSyncWorkerPool, '_clusterDeltas').andReturn({create: {}, modify: {}, destroy: []})
NylasSyncWorkerPool._handleDeltas(@sampleDeltas)
expect(Actions.longPollReceivedRawDeltas).toHaveBeenCalled()
it "should call helper methods for all creates first, then modifications, then destroys", ->
spyOn(Actions, 'longPollProcessedDeltas')
handleDeltaDeletionPromises = []
resolveDeltaDeletionPromises = ->
fn() for fn in handleDeltaDeletionPromises
handleDeltaDeletionPromises = []
spyOn(NylasSyncWorkerPool, '_handleDeltaDeletion').andCallFake ->
new Promise (resolve, reject) ->
handleDeltaDeletionPromises.push(resolve)
handleModelResponsePromises = []
resolveModelResponsePromises = ->
fn() for fn in handleModelResponsePromises
handleModelResponsePromises = []
spyOn(NylasAPI, '_handleModelResponse').andCallFake ->
new Promise (resolve, reject) ->
handleModelResponsePromises.push(resolve)
spyOn(NylasSyncWorkerPool, '_clusterDeltas').andReturn(JSON.parse(JSON.stringify(@sampleClustered)))
NylasSyncWorkerPool._handleDeltas(@sampleDeltas)
createTypes = Object.keys(@sampleClustered['create'])
expect(NylasAPI._handleModelResponse.calls.length).toEqual(createTypes.length)
expect(NylasAPI._handleModelResponse.calls[0].args[0]).toEqual(_.values(@sampleClustered['create'][createTypes[0]]))
expect(NylasSyncWorkerPool._handleDeltaDeletion.calls.length).toEqual(0)
NylasAPI._handleModelResponse.reset()
resolveModelResponsePromises()
advanceClock()
modifyTypes = Object.keys(@sampleClustered['modify'])
expect(NylasAPI._handleModelResponse.calls.length).toEqual(modifyTypes.length)
expect(NylasAPI._handleModelResponse.calls[0].args[0]).toEqual(_.values(@sampleClustered['modify'][modifyTypes[0]]))
expect(NylasSyncWorkerPool._handleDeltaDeletion.calls.length).toEqual(0)
NylasAPI._handleModelResponse.reset()
resolveModelResponsePromises()
advanceClock()
destroyCount = @sampleClustered['destroy'].length
expect(NylasSyncWorkerPool._handleDeltaDeletion.calls.length).toEqual(destroyCount)
expect(NylasSyncWorkerPool._handleDeltaDeletion.calls[0].args[0]).toEqual(@sampleClustered['destroy'][0])
expect(Actions.longPollProcessedDeltas).not.toHaveBeenCalled()
resolveDeltaDeletionPromises()
advanceClock()
expect(Actions.longPollProcessedDeltas).toHaveBeenCalled()
describe "clusterDeltas", ->
beforeEach ->
@sampleDeltas = JSON.parse(fs.readFileSync("#{fixturesPath}/sample.json"))
@expectedClustered = JSON.parse(fs.readFileSync("#{fixturesPath}/sample-clustered.json"))
it "should collect create/modify events into a hash by model type", ->
{create, modify} = NylasSyncWorkerPool._clusterDeltas(@sampleDeltas)
expect(create).toEqual(@expectedClustered.create)
expect(modify).toEqual(@expectedClustered.modify)
it "should collect destroys into an array", ->
{destroy} = NylasSyncWorkerPool._clusterDeltas(@sampleDeltas)
expect(destroy).toEqual(@expectedClustered.destroy)
describe "handleDeltaDeletion", ->
beforeEach ->
@thread = new Thread(id: 'idhere')
@delta =
"cursor": "bb95ddzqtr2gpmvgrng73t6ih",
"object": "thread",
"event": "delete",
"id": @thread.id,
"timestamp": "2015-08-26T17:36:45.297Z"
spyOn(DatabaseTransaction.prototype, '_query').andCallFake -> Promise.resolve([])
spyOn(DatabaseTransaction.prototype, 'unpersistModel')
it "should resolve if the object cannot be found", ->
spyOn(DatabaseStore, 'find').andCallFake (klass, id) =>
return Promise.resolve(null)
waitsForPromise =>
NylasSyncWorkerPool._handleDeltaDeletion(@delta)
runs =>
expect(DatabaseStore.find).toHaveBeenCalledWith(Thread, 'idhere')
expect(DatabaseTransaction.prototype.unpersistModel).not.toHaveBeenCalled()
it "should call unpersistModel if the object exists", ->
spyOn(DatabaseStore, 'find').andCallFake (klass, id) =>
return Promise.resolve(@thread)
waitsForPromise =>
NylasSyncWorkerPool._handleDeltaDeletion(@delta)
runs =>
expect(DatabaseStore.find).toHaveBeenCalledWith(Thread, 'idhere')
expect(DatabaseTransaction.prototype.unpersistModel).toHaveBeenCalledWith(@thread)
describe "handleModelResponse", ->
# SEE spec/nylas-api-spec.coffee