// handleMemPoolMsg is invoked when a peer receives a mempool bitcoin message.
// It creates and sends an inventory message with the contents of the memory
// pool up to the maximum inventory allowed per message.
func (p *peer) handleMemPoolMsg(msg *btcwire.MsgMemPool) {
// Generate inventory message with the available transactions in the
// transaction memory pool. Limit it to the max allowed inventory
// per message. The the NewMsgInvSizeHint function automatically limits
// the passed hint to the maximum allowed, so it's safe to pass it
// without double checking it here.
hashes := p.server.txMemPool.TxShas()
invMsg := btcwire.NewMsgInvSizeHint(uint(len(hashes)))
for i, hash := range hashes {
// Another thread might have removed the transaction from the
// pool since the initial query.
if !p.server.txMemPool.IsTransactionInPool(hash) {
continue
}
iv := btcwire.NewInvVect(btcwire.InvTypeTx, hash)
invMsg.AddInvVect(iv)
if i+1 >= btcwire.MaxInvPerMsg {
break
}
}
// Send the inventory message if there is anything to send.
if len(invMsg.InvList) > 0 {
p.QueueMessage(invMsg, nil)
}
}
// TestInv tests the MsgInv API.
func TestInv(t *testing.T) {
pver := btcwire.ProtocolVersion
// Ensure the command is expected value.
wantCmd := "inv"
msg := btcwire.NewMsgInv()
if cmd := msg.Command(); cmd != wantCmd {
t.Errorf("NewMsgInv: wrong command - got %v want %v",
cmd, wantCmd)
}
// Ensure max payload is expected value for latest protocol version.
// Num inventory vectors (varInt) + max allowed inventory vectors.
wantPayload := uint32(1800009)
maxPayload := msg.MaxPayloadLength(pver)
if maxPayload != wantPayload {
t.Errorf("MaxPayloadLength: wrong max payload length for "+
"protocol version %d - got %v, want %v", pver,
maxPayload, wantPayload)
}
// Ensure inventory vectors are added properly.
hash := btcwire.ShaHash{}
iv := btcwire.NewInvVect(btcwire.InvTypeBlock, &hash)
err := msg.AddInvVect(iv)
if err != nil {
t.Errorf("AddInvVect: %v", err)
}
if msg.InvList[0] != iv {
t.Errorf("AddInvVect: wrong invvect added - got %v, want %v",
spew.Sprint(msg.InvList[0]), spew.Sprint(iv))
}
// Ensure adding more than the max allowed inventory vectors per
// message returns an error.
for i := 0; i < btcwire.MaxInvPerMsg; i++ {
err = msg.AddInvVect(iv)
}
if err == nil {
t.Errorf("AddInvVect: expected error on too many inventory " +
"vectors not received")
}
// Ensure creating the message with a size hint larger than the max
// works as expected.
msg = btcwire.NewMsgInvSizeHint(btcwire.MaxInvPerMsg + 1)
wantCap := btcwire.MaxInvPerMsg
if cap(msg.InvList) != wantCap {
t.Errorf("NewMsgInvSizeHint: wrong cap for size hint - "+
"got %v, want %v", cap(msg.InvList), wantCap)
}
return
}