From f2765201866b59ef52b2ebc92f602a7c8de002ca Mon Sep 17 00:00:00 2001
From: c9s <yoan@maicoin.com>
Date: Tue, 4 Aug 2020 20:04:15 +0800
Subject: [PATCH] improve error messages

---
 bbgo/stock.go | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/bbgo/stock.go b/bbgo/stock.go
index 0dd99593e..fd966c735 100644
--- a/bbgo/stock.go
+++ b/bbgo/stock.go
@@ -5,6 +5,7 @@ import (
 	"github.com/c9s/bbgo/pkg/bbgo/types"
 	"math"
 	"strings"
+	"sync"
 )
 
 func zero(a float64) bool {
@@ -48,18 +49,25 @@ func (slice StockSlice) Quantity() (total float64) {
 }
 
 type StockManager struct {
+	mu sync.Mutex
+
 	Symbol             string
 	TradingFeeCurrency string
 	Stocks             StockSlice
 	PendingSells       StockSlice
 }
 
-func (m *StockManager) Stock(buy Stock) error {
-	m.Stocks = append(m.Stocks, buy)
+func (m *StockManager) stock(stock Stock) error {
+	m.mu.Lock()
+	m.Stocks = append(m.Stocks, stock)
+	m.mu.Unlock()
 	return m.flushPendingSells()
 }
 
 func (m *StockManager) squash() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
 	var squashed StockSlice
 	for _, stock := range m.Stocks {
 		if !zero(stock.Quantity) {
@@ -70,22 +78,27 @@ func (m *StockManager) squash() {
 }
 
 func (m *StockManager) flushPendingSells() error {
-	if len(m.Stocks) > 0 && len(m.PendingSells) > 0 {
+	if len(m.Stocks) == 0 || len(m.PendingSells) == 0 {
+		return nil
+	}
 
-		pendingSells := m.PendingSells
-		m.PendingSells = nil
+	pendingSells := m.PendingSells
+	m.PendingSells = nil
 
-		for _, sell := range pendingSells {
-			if err := m.Consume(sell); err != nil {
-				return err
-			}
+	for _, sell := range pendingSells {
+		if err := m.consume(sell); err != nil {
+			return err
 		}
 	}
 
 	return nil
 }
 
-func (m *StockManager) Consume(sell Stock) error {
+func (m *StockManager) consume(sell Stock) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+
 	if len(m.Stocks) == 0 {
 		m.PendingSells = append(m.PendingSells, sell)
 		return nil
@@ -158,12 +171,12 @@ func (m *StockManager) AddTrades(trades []types.Trade) (checkpoints []int, err e
 			}
 
 			stock := toStock(trade)
-			if err := m.Stock(stock); err != nil {
+			if err := m.stock(stock); err != nil {
 				return checkpoints, err
 			}
 		} else {
 			stock := toStock(trade)
-			if err := m.Consume(stock); err != nil {
+			if err := m.consume(stock); err != nil {
 				return checkpoints, err
 			}
 		}