github.com/noirx94/tendermintmp@v0.0.1/rpc/client/helpers.go (about)

     1  package client
     2  
     3  import (
     4  	"context"
     5  	"errors"
     6  	"fmt"
     7  	"time"
     8  
     9  	"github.com/tendermint/tendermint/types"
    10  )
    11  
    12  // Waiter is informed of current height, decided whether to quit early
    13  type Waiter func(delta int64) (abort error)
    14  
    15  // DefaultWaitStrategy is the standard backoff algorithm,
    16  // but you can plug in another one
    17  func DefaultWaitStrategy(delta int64) (abort error) {
    18  	if delta > 10 {
    19  		return fmt.Errorf("waiting for %d blocks... aborting", delta)
    20  	} else if delta > 0 {
    21  		// estimate of wait time....
    22  		// wait half a second for the next block (in progress)
    23  		// plus one second for every full block
    24  		delay := time.Duration(delta-1)*time.Second + 500*time.Millisecond
    25  		time.Sleep(delay)
    26  	}
    27  	return nil
    28  }
    29  
    30  // Wait for height will poll status at reasonable intervals until
    31  // the block at the given height is available.
    32  //
    33  // If waiter is nil, we use DefaultWaitStrategy, but you can also
    34  // provide your own implementation
    35  func WaitForHeight(c StatusClient, h int64, waiter Waiter) error {
    36  	if waiter == nil {
    37  		waiter = DefaultWaitStrategy
    38  	}
    39  	delta := int64(1)
    40  	for delta > 0 {
    41  		s, err := c.Status(context.Background())
    42  		if err != nil {
    43  			return err
    44  		}
    45  		delta = h - s.SyncInfo.LatestBlockHeight
    46  		// wait for the time, or abort early
    47  		if err := waiter(delta); err != nil {
    48  			return err
    49  		}
    50  	}
    51  
    52  	return nil
    53  }
    54  
    55  // WaitForOneEvent subscribes to a websocket event for the given
    56  // event time and returns upon receiving it one time, or
    57  // when the timeout duration has expired.
    58  //
    59  // This handles subscribing and unsubscribing under the hood
    60  func WaitForOneEvent(c EventsClient, evtTyp string, timeout time.Duration) (types.TMEventData, error) {
    61  	const subscriber = "helpers"
    62  	ctx, cancel := context.WithTimeout(context.Background(), timeout)
    63  	defer cancel()
    64  
    65  	// register for the next event of this type
    66  	eventCh, err := c.Subscribe(ctx, subscriber, types.QueryForEvent(evtTyp).String())
    67  	if err != nil {
    68  		return nil, fmt.Errorf("failed to subscribe: %w", err)
    69  	}
    70  	// make sure to unregister after the test is over
    71  	defer func() {
    72  		if deferErr := c.UnsubscribeAll(ctx, subscriber); deferErr != nil {
    73  			panic(err)
    74  		}
    75  	}()
    76  
    77  	select {
    78  	case event := <-eventCh:
    79  		return event.Data.(types.TMEventData), nil
    80  	case <-ctx.Done():
    81  		return nil, errors.New("timed out waiting for event")
    82  	}
    83  }