20190206_blog_parts_rev_27ce4eb78bdf5d9b742ed05babe9b86a434733a1_tx_pool

broadcast_lines_in_tx_pool.go

	if list := pool.pending[from]; list != nil && list.Overlaps(tx) {
		// Nonce already pending, check if required price bump is met
		inserted, old := list.Add(tx, pool.config.PriceBump)
		if !inserted {
			pendingDiscardCounter.Inc(1)
			return false, ErrReplaceUnderpriced
		}
		// New transaction is better, replace old one
		if old != nil {
			pool.all.Remove(old.Hash())
			pool.priced.Removed()
			pendingReplaceCounter.Inc(1)
		}
		pool.all.Add(tx)
		pool.priced.Put(tx)
		pool.journalTx(from, tx)

		log.Trace("Pooled new executable transaction", "hash", hash, "from", from, "to", tx.To())

		// We've directly injected a replacement transaction, notify subsystems
		go pool.txFeed.Send(NewTxsEvent{types.Transactions{tx}})

		return old != nil, nil
	}