Rename methods and functions in submission system (#4298)

It's the first time I get into this code and the naming has made it
hard to understand. So, I decided to make the naming more
understandable.

services/horizon/internal/txsub/sequence/queue.go → services/horizon/internal/txsub/sequence/account_tx_submission_queue.go

@@ -5,24 +5,24 @@ import (
 	"time"
 )
 
-// Queue manages the submission queue for a single source account. The
+// AccountTxSubmissionQueue manages the submission queue for a single source account. The
 // transaction system uses Push to enqueue submissions for given sequence
 // numbers.
 //
-// Queue maintains a priority queue of pending submissions, and when updated
-// (via the Update() method) with the current sequence number of the account
+// AccountTxSubmissionQueue maintains a priority queue of pending submissions, and when updated
+// (via the NotifyLastAccountSequence() method) with the current sequence number of the account
 // being managed, queued submissions that can be acted upon will be unblocked.
 //
-type Queue struct {
+type AccountTxSubmissionQueue struct {
 	lastActiveAt time.Time
 	timeout      time.Duration
 	nextSequence uint64
 	queue        pqueue
 }
 
-// NewQueue creates a new *Queue
-func NewQueue() *Queue {
-	result := &Queue{
+// NewAccountTxSubmissionQueue creates a new *AccountTxSubmissionQueue
+func NewAccountTxSubmissionQueue() *AccountTxSubmissionQueue {
+	result := &AccountTxSubmissionQueue{
 		lastActiveAt: time.Now(),
 		timeout:      10 * time.Second,
 		queue:        nil,
@@ -34,7 +34,7 @@ func NewQueue() *Queue {
 }
 
 // Size returns the count of currently buffered submissions in the queue.
-func (q *Queue) Size() int {
+func (q *AccountTxSubmissionQueue) Size() int {
 	return len(q.queue)
 }
 
@@ -43,26 +43,26 @@ func (q *Queue) Size() int {
 // to do so.
 //
 // Push does not perform any triggering (which
-// occurs in Update(), even if the current sequence number for this queue is
+// occurs in NotifyLastAccountSequence(), even if the current sequence number for this queue is
 // the same as the provided sequence, to keep internal complexity much lower.
 // Given that, the recommended usage pattern is:
 //
 // 1. Push the submission onto the queue
 // 2. Load the current sequence number for the source account from the DB
-// 3. Call Update() with the result from step 2 to trigger the submission if
+// 3. Call NotifyLastAccountSequence() with the result from step 2 to trigger the submission if
 //		possible
-func (q *Queue) Push(sequence uint64) <-chan error {
+func (q *AccountTxSubmissionQueue) Push(sequence uint64) <-chan error {
 	ch := make(chan error, 1)
 	heap.Push(&q.queue, item{sequence, ch})
 	return ch
 }
 
-// Update notifies the queue that the provided sequence number is the latest
+// NotifyLastAccountSequence notifies the queue that the provided sequence number is the latest
 // seen value for the account that this queue manages submissions for.
 //
 // This function is monotonic... calling it with a sequence number lower than
 // the latest seen sequence number is a noop.
-func (q *Queue) Update(sequence uint64) {
+func (q *AccountTxSubmissionQueue) NotifyLastAccountSequence(sequence uint64) {
 	if q.nextSequence <= sequence {
 		q.nextSequence = sequence + 1
 	}
@@ -113,7 +113,7 @@ func (q *Queue) Update(sequence uint64) {
 }
 
 // helper function for interacting with the priority queue
-func (q *Queue) head() (chan error, uint64) {
+func (q *AccountTxSubmissionQueue) head() (chan error, uint64) {
 	if len(q.queue) == 0 {
 		return nil, uint64(0)
 	}
@@ -122,7 +122,7 @@ func (q *Queue) head() (chan error, uint64) {
 }
 
 // helper function for interacting with the priority queue
-func (q *Queue) pop() (chan error, uint64) {
+func (q *AccountTxSubmissionQueue) pop() (chan error, uint64) {
 	i := heap.Pop(&q.queue).(item)
 
 	return i.Chan, i.Sequence
@@ -134,7 +134,7 @@ type item struct {
 	Chan     chan error
 }
 
-// pqueue is a priority queue used by Queue to manage buffered submissions.  It
+// pqueue is a priority queue used by AccountTxSubmissionQueue to manage buffered submissions.  It
 // implements heap.Interface.
 type pqueue []item
 

services/horizon/internal/txsub/sequence/queue_test.go → services/horizon/internal/txsub/sequence/account_tx_submission_queue_test.go

@@ -15,12 +15,12 @@ import (
 type QueueTestSuite struct {
 	suite.Suite
 	ctx   context.Context
-	queue *Queue
+	queue *AccountTxSubmissionQueue
 }
 
 func (suite *QueueTestSuite) SetupTest() {
 	suite.ctx = test.Context()
-	suite.queue = NewQueue()
+	suite.queue = NewAccountTxSubmissionQueue()
 }
 
 //Push adds the provided channel on to the priority queue
@@ -43,35 +43,35 @@ func (suite *QueueTestSuite) TestQueue_Push() {
 
 // Tests the update method
 func (suite *QueueTestSuite) TestQueue_Update() {
-	// Update removes sequences that are submittable or in the past
+	// NotifyLastAccountSequence removes sequences that are submittable or in the past
 	results := []<-chan error{
 		suite.queue.Push(1),
 		suite.queue.Push(2),
 		suite.queue.Push(3),
 		suite.queue.Push(4),
 	}
 
-	suite.queue.Update(2)
+	suite.queue.NotifyLastAccountSequence(2)
 
 	// the update above signifies that 2 is the accounts current sequence,
 	// meaning that 3 is submittable, and so only 4 should still be queued
 	assert.Equal(suite.T(), 1, suite.queue.Size())
 	_, s := suite.queue.head()
 	assert.Equal(suite.T(), uint64(4), s)
 
-	suite.queue.Update(4)
+	suite.queue.NotifyLastAccountSequence(4)
 	assert.Equal(suite.T(), 0, suite.queue.Size())
 
 	assert.Equal(suite.T(), ErrBadSequence, <-results[0])
 	assert.Equal(suite.T(), ErrBadSequence, <-results[1])
 	assert.Equal(suite.T(), nil, <-results[2])
 	assert.Equal(suite.T(), ErrBadSequence, <-results[3])
 
-	// Update clears the queue if the head has not been released within the time limit
+	// NotifyLastAccountSequence clears the queue if the head has not been released within the time limit
 	suite.queue.timeout = 1 * time.Millisecond
 	result := suite.queue.Push(2)
 	<-time.After(10 * time.Millisecond)
-	suite.queue.Update(0)
+	suite.queue.NotifyLastAccountSequence(0)
 
 	assert.Equal(suite.T(), 0, suite.queue.Size())
 	assert.Equal(suite.T(), ErrBadSequence, <-result)

services/horizon/internal/txsub/sequence/manager.go

@@ -14,14 +14,14 @@ import (
 type Manager struct {
 	mutex   sync.Mutex
 	MaxSize int
-	queues  map[string]*Queue
+	queues  map[string]*AccountTxSubmissionQueue
 }
 
 // NewManager returns a new manager
 func NewManager() *Manager {
 	return &Manager{
 		MaxSize: 1024, //TODO: make MaxSize configurable
-		queues:  map[string]*Queue{},
+		queues:  map[string]*AccountTxSubmissionQueue{},
 	}
 }
 
@@ -70,15 +70,15 @@ func (m *Manager) Push(address string, sequence uint64) <-chan error {
 
 	aq, ok := m.queues[address]
 	if !ok {
-		aq = NewQueue()
+		aq = NewAccountTxSubmissionQueue()
 		m.queues[address] = aq
 	}
 
 	return aq.Push(sequence)
 }
 
 // Update notifies the manager of newly loaded account sequence information.  The manager uses this information
-// to notify requests to submit that they should proceed.  See Queue#Update for the actual meat of the logic.
+// to notify requests to submit that they should proceed.  See AccountTxSubmissionQueue#NotifyLastAccountSequence for the actual meat of the logic.
 func (m *Manager) Update(updates map[string]uint64) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
@@ -89,7 +89,7 @@ func (m *Manager) Update(updates map[string]uint64) {
 			continue
 		}
 
-		queue.Update(seq)
+		queue.NotifyLastAccountSequence(seq)
 		if queue.Size() == 0 {
 			delete(m.queues, address)
 		}

services/horizon/internal/txsub/sequence/manager_test.go

@@ -20,7 +20,7 @@ func TestManager_Push(t *testing.T) {
 	assert.Equal(t, 1, mgr.queues["2"].Size())
 }
 
-// Test the Update method
+// Test the NotifyLastAccountSequence method
 func TestManager_Update(t *testing.T) {
 	mgr := NewManager()
 	results := []<-chan error{

services/horizon/internal/txsub/submitter.go

@@ -50,7 +50,7 @@ func (sub *submitter) Submit(ctx context.Context, env string) (result Submission
 		return
 	}
 
-	// interpet response
+	// interpret response
 	if cresp.IsException() {
 		result.Err = errors.Errorf("stellar-core exception: %s", cresp.Exception)
 		return