// PushGetDirBlocksMsg sends a getdirblocks message for the provided block locator
// and stop hash. It will ignore back-to-back duplicate requests.
func (p *peer) PushGetDirBlocksMsg(locator blockchain.BlockLocator, stopHash *wire.ShaHash) error {
// Extract the begin hash from the block locator, if one was specified,
// to use for filtering duplicate getblocks requests.
// request.
var beginHash *wire.ShaHash
if len(locator) > 0 {
beginHash = locator[0]
}
// Filter duplicate getdirblocks requests.
if p.prevGetBlocksStop != nil && p.prevGetBlocksBegin != nil &&
beginHash != nil && stopHash.IsEqual(p.prevGetBlocksStop) &&
beginHash.IsEqual(p.prevGetBlocksBegin) {
peerLog.Tracef("Filtering duplicate [getdirblocks] with begin "+
"hash %v, stop hash %v", beginHash, stopHash)
return nil
}
// Construct the getblocks request and queue it to be sent.
msg := wire.NewMsgGetDirBlocks(stopHash)
for _, hash := range locator {
err := msg.AddBlockLocatorHash(hash)
if err != nil {
return err
}
}
p.QueueMessage(msg, nil)
// Update the previous getblocks request information for filtering
// duplicates.
p.prevGetBlocksBegin = beginHash
p.prevGetBlocksStop = stopHash
return nil
}
