From f418fe3772f5c562521d0818747cb6563c49c324 Mon Sep 17 00:00:00 2001
From: Josh Rickmar <jrick@conformal.com>
Date: Mon, 16 Jun 2014 15:47:05 -0500
Subject: [PATCH] Remove tx send/recv write order synchronization.

This was only necessary for a very old version of the transaction
store.  The current implementation stores both sent (debit) and
received (credit) records for individual transactions.
---
 cmd.go       |  4 ----
 rpcclient.go | 18 ---------------
 rpcserver.go | 64 ----------------------------------------------------
 3 files changed, 86 deletions(-)

diff --git a/cmd.go b/cmd.go
index fa947a7..909371e 100644
--- a/cmd.go
+++ b/cmd.go
@@ -182,10 +182,6 @@ func main() {
 	server.Start()
 
 	// Begin maintanence goroutines.
-	go SendBeforeReceiveHistorySync(SendTxHistSyncChans.add,
-		SendTxHistSyncChans.done,
-		SendTxHistSyncChans.remove,
-		SendTxHistSyncChans.access)
 	go StoreNotifiedMempoolRecvTxs(NotifiedRecvTxChans.add,
 		NotifiedRecvTxChans.remove,
 		NotifiedRecvTxChans.access)
diff --git a/rpcclient.go b/rpcclient.go
index cfc7cd8..fe2ad22 100644
--- a/rpcclient.go
+++ b/rpcclient.go
@@ -227,24 +227,6 @@ func (n recvTx) handleNotification() error {
 		return fmt.Errorf("cannot get current block: %v", err)
 	}
 
-	// For transactions originating from this wallet, the sent tx history should
-	// be recorded before the received history.  If wallet created this tx, wait
-	// for the sent history to finish being recorded before continuing.
-	//
-	// TODO(jrick) this is wrong due to tx malleability.  Cannot safely use the
-	// txsha as an identifier.
-	req := SendTxHistSyncRequest{
-		txsha:    *n.tx.Sha(),
-		response: make(chan SendTxHistSyncResponse),
-	}
-	SendTxHistSyncChans.access <- req
-	resp := <-req.response
-	if resp.ok {
-		// Wait until send history has been recorded.
-		<-resp.c
-		SendTxHistSyncChans.remove <- *n.tx.Sha()
-	}
-
 	AcctMgr.Grab()
 	defer AcctMgr.Release()
 
diff --git a/rpcserver.go b/rpcserver.go
index c6401f1..7fca7ca 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -1884,10 +1884,6 @@ func sendPairs(icmd btcjson.Cmd, account string, amounts map[string]btcutil.Amou
 		}
 	}
 
-	// Mark txid as having send history so handlers adding receive history
-	// wait until all send history has been written.
-	SendTxHistSyncChans.add <- *createdTx.tx.Sha()
-
 	// If a change address was added, sync wallet to disk and request
 	// transaction notifications to the change address.
 	if createdTx.changeAddr != nil {
@@ -1903,10 +1899,8 @@ func sendPairs(icmd btcjson.Cmd, account string, amounts map[string]btcutil.Amou
 
 	txSha, err := client.SendRawTransaction(createdTx.tx.MsgTx(), false)
 	if err != nil {
-		SendTxHistSyncChans.remove <- *createdTx.tx.Sha()
 		return nil, err
 	}
-
 	if err := handleSendRawTxReply(icmd, txSha, a, createdTx); err != nil {
 		return nil, err
 	}
@@ -1991,61 +1985,6 @@ func SendToAddress(icmd btcjson.Cmd) (interface{}, error) {
 	return sendPairs(cmd, "", pairs, 1)
 }
 
-// Channels to manage SendBeforeReceiveHistorySync.
-var SendTxHistSyncChans = struct {
-	add, done, remove chan btcwire.ShaHash
-	access            chan SendTxHistSyncRequest
-}{
-	add:    make(chan btcwire.ShaHash),
-	remove: make(chan btcwire.ShaHash),
-	done:   make(chan btcwire.ShaHash),
-	access: make(chan SendTxHistSyncRequest),
-}
-
-// SendTxHistSyncRequest requests a SendTxHistSyncResponse from
-// SendBeforeReceiveHistorySync.
-type SendTxHistSyncRequest struct {
-	txsha    btcwire.ShaHash
-	response chan SendTxHistSyncResponse
-}
-
-// SendTxHistSyncResponse is the response
-type SendTxHistSyncResponse struct {
-	c  chan struct{}
-	ok bool
-}
-
-// SendBeforeReceiveHistorySync manages a set of transaction hashes
-// created by this wallet.  For each newly added txsha, a channel is
-// created.  Once the send history has been recorded, the txsha should
-// be messaged across done, causing the internal channel to be closed.
-// Before receive history is recorded, access should be used to check
-// if there are or were any goroutines writing send history, and if
-// so, wait until the channel is closed after a done message.
-func SendBeforeReceiveHistorySync(add, done, remove chan btcwire.ShaHash,
-	access chan SendTxHistSyncRequest) {
-
-	m := make(map[btcwire.ShaHash]chan struct{})
-	for {
-		select {
-		case txsha := <-add:
-			m[txsha] = make(chan struct{})
-
-		case txsha := <-remove:
-			delete(m, txsha)
-
-		case txsha := <-done:
-			if c, ok := m[txsha]; ok {
-				close(c)
-			}
-
-		case req := <-access:
-			c, ok := m[req.txsha]
-			req.response <- SendTxHistSyncResponse{c: c, ok: ok}
-		}
-	}
-}
-
 func handleSendRawTxReply(icmd btcjson.Cmd, txSha *btcwire.ShaHash, a *Account, txInfo *CreatedTx) error {
 	// Add to transaction store.
 	txr, err := a.TxStore.InsertTx(txInfo.tx, nil)
@@ -2073,9 +2012,6 @@ func handleSendRawTxReply(icmd btcjson.Cmd, txSha *btcwire.ShaHash, a *Account,
 		}
 	}
 
-	// Signal that received notifiations are ok to add now.
-	SendTxHistSyncChans.done <- *txInfo.tx.Sha()
-
 	// Disk sync tx and utxo stores.
 	if err := AcctMgr.ds.FlushAccount(a); err != nil {
 		log.Errorf("Cannot write account: %v", err)