Exemplo n.º 1
0
// expire is the generic check that move expired tasks from a pending pool back
// into a task pool, returning all entities caught with expired tasks.
//
// Note, this method expects the queue lock to be already held. The
// reason the lock is not obtained in here is because the parameters already need
// to access the queue, so they already need a lock anyway.
func (q *queue) expire(timeout time.Duration, pendPool map[string]*fetchRequest, taskQueue *prque.Prque, timeoutMeter metrics.Meter) map[string]int {
	// Iterate over the expired requests and return each to the queue
	expiries := make(map[string]int)
	for id, request := range pendPool {
		if time.Since(request.Time) > timeout {
			// Update the metrics with the timeout
			timeoutMeter.Mark(1)

			// Return any non satisfied requests to the pool
			for hash, index := range request.Hashes {
				taskQueue.Push(hash, float32(index))
			}
			for _, header := range request.Headers {
				taskQueue.Push(header, -float32(header.Number.Uint64()))
			}
			// Add the peer to the expiry report along the the number of failed requests
			expirations := len(request.Hashes)
			if expirations < len(request.Headers) {
				expirations = len(request.Headers)
			}
			expiries[id] = expirations
		}
	}
	// Remove the expired requests from the pending pool
	for id, _ := range expiries {
		delete(pendPool, id)
	}
	return expiries
}
Exemplo n.º 2
0
// Cancel aborts a fetch request, returning all pending hashes to the task queue.
func (q *queue) cancel(request *fetchRequest, taskQueue *prque.Prque, pendPool map[string]*fetchRequest) {
	q.lock.Lock()
	defer q.lock.Unlock()

	for hash, index := range request.Hashes {
		taskQueue.Push(hash, float32(index))
	}
	for _, header := range request.Headers {
		taskQueue.Push(header, -float32(header.Number.Uint64()))
	}
	delete(pendPool, request.Peer.id)
}
Exemplo n.º 3
0
// reserveHashes reserves a set of hashes for the given peer, skipping previously
// failed ones.
//
// Note, this method expects the queue lock to be already held for writing. The
// reason the lock is not obtained in here is because the parameters already need
// to access the queue, so they already need a lock anyway.
func (q *queue) reserveHashes(p *peer, count int, taskQueue *prque.Prque, taskGen func(int), pendPool map[string]*fetchRequest, maxPending int) *fetchRequest {
	// Short circuit if the peer's already downloading something (sanity check to
	// not corrupt state)
	if _, ok := pendPool[p.id]; ok {
		return nil
	}
	// Calculate an upper limit on the hashes we might fetch (i.e. throttling)
	allowance := maxPending
	if allowance > 0 {
		for _, request := range pendPool {
			allowance -= len(request.Hashes)
		}
	}
	// If there's a task generator, ask it to fill our task queue
	if taskGen != nil && taskQueue.Size() < allowance {
		taskGen(allowance - taskQueue.Size())
	}
	if taskQueue.Empty() {
		return nil
	}
	// Retrieve a batch of hashes, skipping previously failed ones
	send := make(map[common.Hash]int)
	skip := make(map[common.Hash]int)

	for proc := 0; (allowance == 0 || proc < allowance) && len(send) < count && !taskQueue.Empty(); proc++ {
		hash, priority := taskQueue.Pop()
		if p.Lacks(hash.(common.Hash)) {
			skip[hash.(common.Hash)] = int(priority)
		} else {
			send[hash.(common.Hash)] = int(priority)
		}
	}
	// Merge all the skipped hashes back
	for hash, index := range skip {
		taskQueue.Push(hash, float32(index))
	}
	// Assemble and return the block download request
	if len(send) == 0 {
		return nil
	}
	request := &fetchRequest{
		Peer:   p,
		Hashes: send,
		Time:   time.Now(),
	}
	pendPool[p.id] = request

	return request
}
Exemplo n.º 4
0
// expire is the generic check that move expired tasks from a pending pool back
// into a task pool, returning all entities caught with expired tasks.
//
// Note, this method expects the queue lock to be already held for writing. The
// reason the lock is not obtained in here is because the parameters already need
// to access the queue, so they already need a lock anyway.
func (q *queue) expire(timeout time.Duration, pendPool map[string]*fetchRequest, taskQueue *prque.Prque, timeoutMeter metrics.Meter) []string {
	// Iterate over the expired requests and return each to the queue
	peers := []string{}
	for id, request := range pendPool {
		if time.Since(request.Time) > timeout {
			// Update the metrics with the timeout
			timeoutMeter.Mark(1)

			// Return any non satisfied requests to the pool
			for hash, index := range request.Hashes {
				taskQueue.Push(hash, float32(index))
			}
			for _, header := range request.Headers {
				taskQueue.Push(header, -float32(header.Number.Uint64()))
			}
			peers = append(peers, id)
		}
	}
	// Remove the expired requests from the pending pool
	for _, id := range peers {
		delete(pendPool, id)
	}
	return peers
}
Exemplo n.º 5
0
// deliver injects a data retrieval response into the results queue.
//
// Note, this method expects the queue lock to be already held for writing. The
// reason the lock is not obtained in here is because the parameters already need
// to access the queue, so they already need a lock anyway.
func (q *queue) deliver(id string, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque,
	pendPool map[string]*fetchRequest, donePool map[common.Hash]struct{}, reqTimer metrics.Timer,
	results int, reconstruct func(header *types.Header, index int, result *fetchResult) error) (int, error) {

	// Short circuit if the data was never requested
	request := pendPool[id]
	if request == nil {
		return 0, errNoFetchesPending
	}
	reqTimer.UpdateSince(request.Time)
	delete(pendPool, id)

	// If no data items were retrieved, mark them as unavailable for the origin peer
	if results == 0 {
		for _, header := range request.Headers {
			request.Peer.MarkLacking(header.Hash())
		}
	}
	// Assemble each of the results with their headers and retrieved data parts
	var (
		accepted int
		failure  error
		useful   bool
	)
	for i, header := range request.Headers {
		// Short circuit assembly if no more fetch results are found
		if i >= results {
			break
		}
		// Reconstruct the next result if contents match up
		index := int(header.Number.Int64() - int64(q.resultOffset))
		if index >= len(q.resultCache) || index < 0 || q.resultCache[index] == nil {
			failure = errInvalidChain
			break
		}
		if err := reconstruct(header, i, q.resultCache[index]); err != nil {
			failure = err
			break
		}
		donePool[header.Hash()] = struct{}{}
		q.resultCache[index].Pending--
		useful = true
		accepted++

		// Clean up a successful fetch
		request.Headers[i] = nil
		delete(taskPool, header.Hash())
	}
	// Return all failed or missing fetches to the queue
	for _, header := range request.Headers {
		if header != nil {
			taskQueue.Push(header, -float32(header.Number.Uint64()))
		}
	}
	// Wake up WaitResults
	if accepted > 0 {
		q.active.Signal()
	}
	// If none of the data was good, it's a stale delivery
	switch {
	case failure == nil || failure == errInvalidChain:
		return accepted, failure
	case useful:
		return accepted, fmt.Errorf("partial failure: %v", failure)
	default:
		return accepted, errStaleDelivery
	}
}
Exemplo n.º 6
0
// reserveHeaders reserves a set of data download operations for a given peer,
// skipping any previously failed ones. This method is a generic version used
// by the individual special reservation functions.
//
// Note, this method expects the queue lock to be already held for writing. The
// reason the lock is not obtained in here is because the parameters already need
// to access the queue, so they already need a lock anyway.
func (q *queue) reserveHeaders(p *peer, count int, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque,
	pendPool map[string]*fetchRequest, donePool map[common.Hash]struct{}, isNoop func(*types.Header) bool) (*fetchRequest, bool, error) {
	// Short circuit if the pool has been depleted, or if the peer's already
	// downloading something (sanity check not to corrupt state)
	if taskQueue.Empty() {
		return nil, false, nil
	}
	if _, ok := pendPool[p.id]; ok {
		return nil, false, nil
	}
	// Calculate an upper limit on the items we might fetch (i.e. throttling)
	space := len(q.resultCache) - len(donePool)
	for _, request := range pendPool {
		space -= len(request.Headers)
	}
	// Retrieve a batch of tasks, skipping previously failed ones
	send := make([]*types.Header, 0, count)
	skip := make([]*types.Header, 0)

	progress := false
	for proc := 0; proc < space && len(send) < count && !taskQueue.Empty(); proc++ {
		header := taskQueue.PopItem().(*types.Header)

		// If we're the first to request this task, initialise the result container
		index := int(header.Number.Int64() - int64(q.resultOffset))
		if index >= len(q.resultCache) || index < 0 {
			common.Report("index allocation went beyond available resultCache space")
			return nil, false, errInvalidChain
		}
		if q.resultCache[index] == nil {
			components := 1
			if q.mode == FastSync && header.Number.Uint64() <= q.fastSyncPivot {
				components = 2
			}
			q.resultCache[index] = &fetchResult{
				Pending: components,
				Header:  header,
			}
		}
		// If this fetch task is a noop, skip this fetch operation
		if isNoop(header) {
			donePool[header.Hash()] = struct{}{}
			delete(taskPool, header.Hash())

			space, proc = space-1, proc-1
			q.resultCache[index].Pending--
			progress = true
			continue
		}
		// Otherwise unless the peer is known not to have the data, add to the retrieve list
		if p.Lacks(header.Hash()) {
			skip = append(skip, header)
		} else {
			send = append(send, header)
		}
	}
	// Merge all the skipped headers back
	for _, header := range skip {
		taskQueue.Push(header, -float32(header.Number.Uint64()))
	}
	if progress {
		// Wake WaitResults, resultCache was modified
		q.active.Signal()
	}
	// Assemble and return the block download request
	if len(send) == 0 {
		return nil, progress, nil
	}
	request := &fetchRequest{
		Peer:    p,
		Headers: send,
		Time:    time.Now(),
	}
	pendPool[p.id] = request

	return request, progress, nil
}