unexport task and taskList

the less bitswap has to know about, the easier it'll be for readers.
(This now returns Messages.)

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

exchange/bitswap/strategy/ledgermanager.go

@@ -28,7 +28,7 @@ type LedgerManager struct {
 	lock       sync.RWMutex
 	ledgerMap  ledgerMap
 	bs         bstore.Blockstore
-	tasklist   *TaskList
+	tasklist   *taskList
 	outbox     chan Envelope
 	workSignal chan struct{}
 }
@@ -37,7 +37,7 @@ func NewLedgerManager(ctx context.Context, bs bstore.Blockstore) *LedgerManager
 	lm := &LedgerManager{
 		ledgerMap:  make(ledgerMap),
 		bs:         bs,
-		tasklist:   NewTaskList(),
+		tasklist:   newTaskList(),
 		outbox:     make(chan Envelope, 4), // TODO extract constant
 		workSignal: make(chan struct{}),
 	}

exchange/bitswap/strategy/tasklist.go

@@ -8,13 +8,13 @@ import (
 // TODO: at some point, the strategy needs to plug in here
 // to help decide how to sort tasks (on add) and how to select
 // tasks (on getnext). For now, we are assuming a dumb/nice strategy.
-type TaskList struct {
+type taskList struct {
 	tasks   []*Task
 	taskmap map[string]*Task
 }
 
-func NewTaskList() *TaskList {
-	return &TaskList{
+func newTaskList() *taskList {
+	return &taskList{
 		taskmap: make(map[string]*Task),
 	}
 }
@@ -27,7 +27,7 @@ type Task struct {
 
 // Push currently adds a new task to the end of the list
 // TODO: make this into a priority queue
-func (tl *TaskList) Push(block u.Key, priority int, to peer.Peer) {
+func (tl *taskList) Push(block u.Key, priority int, to peer.Peer) {
 	if task, ok := tl.taskmap[taskKey(to, block)]; ok {
 		// TODO: when priority queue is implemented,
 		//       rearrange this Task
@@ -44,7 +44,7 @@ func (tl *TaskList) Push(block u.Key, priority int, to peer.Peer) {
 }
 
 // Pop 'pops' the next task to be performed. Returns nil no task exists.
-func (tl *TaskList) Pop() *Task {
+func (tl *taskList) Pop() *Task {
 	var out *Task
 	for len(tl.tasks) > 0 {
 		// TODO: instead of zero, use exponential distribution
@@ -63,7 +63,7 @@ func (tl *TaskList) Pop() *Task {
 }
 
 // Cancel lazily cancels the sending of a block to a given peer
-func (tl *TaskList) Cancel(k u.Key, p peer.Peer) {
+func (tl *taskList) Cancel(k u.Key, p peer.Peer) {
 	t, ok := tl.taskmap[taskKey(p, k)]
 	if ok {
 		t.theirPriority = -1