From 5c175bf8deb238c3a214ba13b3cdd8a74f0ad850 Mon Sep 17 00:00:00 2001
From: meskio <meskio@sindominio.net>
Date: Sun, 4 Oct 2020 17:09:15 +0200
Subject: [PATCH] Use DB transactions to update balance/create transaction
---
api/purchase.go | 39 +++++++++++++++++++----------------
api/topup.go | 12 +++--------
api/transaction.go | 51 ++++++++++++++++++++++++++++------------------
3 files changed, 55 insertions(+), 47 deletions(-)
diff --git a/api/purchase.go b/api/purchase.go
index 2d0e9c2..0eec3ed 100644
--- a/api/purchase.go
+++ b/api/purchase.go
@@ -2,6 +2,7 @@ package api
import (
"encoding/json"
+ "fmt"
"log"
"net/http"
"time"
@@ -45,12 +46,6 @@ func (a *api) AddPurchase(num int, w http.ResponseWriter, req *http.Request) {
return
}
- httpStatus := a.updateMemberBalance(num, -total)
- if httpStatus != http.StatusOK {
- w.WriteHeader(httpStatus)
- return
- }
-
transaction := Transaction{
MemberNum: num,
Date: time.Now(),
@@ -58,20 +53,28 @@ func (a *api) AddPurchase(num int, w http.ResponseWriter, req *http.Request) {
Type: "purchase",
Total: -total,
}
- err = a.db.Create(&transaction).Error
- if err != nil {
- log.Printf("Can't create purchase: %v\n%v", err, purchase)
- w.WriteHeader(http.StatusInternalServerError)
- return
- }
-
- for _, p := range purchase {
- err := a.db.Model(&Product{}).
- Where("code = ?", p.ProductCode).
- Update("stock", gorm.Expr("stock - ?", p.Ammount)).Error
+ var httpStatus int
+ err = a.db.Transaction(func(tx *gorm.DB) error {
+ httpStatus, err = createTransaction(tx, &transaction)
if err != nil {
- log.Printf("Can't update product stock %d-%d: %v", p.ProductCode, p.Ammount, err)
+ return err
+ }
+
+ for _, p := range purchase {
+ err := tx.Model(&Product{}).
+ Where("code = ?", p.ProductCode).
+ Update("stock", gorm.Expr("stock - ?", p.Ammount)).Error
+ if err != nil {
+ httpStatus = http.StatusInternalServerError
+ return fmt.Errorf("Can't update product stock %d-%d: %v", p.ProductCode, p.Ammount, err)
+ }
}
+ return nil
+ })
+ if err != nil {
+ log.Println(err)
+ w.WriteHeader(httpStatus)
+ return
}
w.Header().Set("Content-Type", "application/json")
diff --git a/api/topup.go b/api/topup.go
index 74ed855..4ee42a6 100644
--- a/api/topup.go
+++ b/api/topup.go
@@ -30,12 +30,6 @@ func (a *api) AddTopup(adminNum int, w http.ResponseWriter, req *http.Request) {
return
}
- httpStatus := a.updateMemberBalance(topup.Member, topup.Ammount)
- if httpStatus != http.StatusOK {
- w.WriteHeader(httpStatus)
- return
- }
-
transaction := Transaction{
MemberNum: topup.Member,
Date: time.Now(),
@@ -46,10 +40,10 @@ func (a *api) AddTopup(adminNum int, w http.ResponseWriter, req *http.Request) {
Type: "topup",
Total: topup.Ammount,
}
- err = a.db.Create(&transaction).Error
+ httpStatus, err := createTransaction(a.db, &transaction)
if err != nil {
- log.Printf("Can't create topup: %v\n%v", err, transaction)
- w.WriteHeader(http.StatusInternalServerError)
+ log.Println(err)
+ w.WriteHeader(httpStatus)
return
}
diff --git a/api/transaction.go b/api/transaction.go
index 0420e43..0ec5c63 100644
--- a/api/transaction.go
+++ b/api/transaction.go
@@ -2,6 +2,7 @@ package api
import (
"encoding/json"
+ "fmt"
"log"
"net/http"
"strconv"
@@ -55,7 +56,7 @@ func (a *api) GetTransaction(num int, role string, w http.ResponseWriter, req *h
w.WriteHeader(http.StatusNotFound)
return
}
- log.Printf("Can't get transaction %s: %v", vars["code"], err)
+ log.Printf("Can't get transaction %s: %v", vars["id"], err)
w.WriteHeader(http.StatusInternalServerError)
return
}
@@ -102,23 +103,33 @@ func (a *api) getTransactionsByMember(num int, w http.ResponseWriter, req *http.
}
}
-func (a *api) updateMemberBalance(num int, ammount int) int {
- var member Member
- err := a.db.Where("num = ?", num).Find(&member).Error
- if err != nil {
- log.Printf("Can't find member %d: %v", num, err)
- return http.StatusNotAcceptable
- }
- if member.Balance < -ammount {
- log.Printf("Member %d don't have enough money (%d-%d)", num, member.Balance, ammount)
- return http.StatusBadRequest
- }
- err = a.db.Model(&Member{}).
- Where("num = ?", num).
- Update("balance", gorm.Expr("balance + ?", ammount)).Error
- if err != nil {
- log.Printf("Can't update update member balance %d-%d: %v", num, ammount, err)
- return http.StatusNotAcceptable
- }
- return http.StatusOK
+func createTransaction(db *gorm.DB, transaction *Transaction) (httpStatus int, err error) {
+ httpStatus = http.StatusOK
+ err = db.Transaction(func(tx *gorm.DB) error {
+ var member Member
+ err := tx.Where("num = ?", transaction.MemberNum).Find(&member).Error
+ if err != nil {
+ httpStatus = http.StatusNotAcceptable
+ return fmt.Errorf("Can't find member %d: %v", transaction.MemberNum, err)
+ }
+ if member.Balance < -transaction.Total {
+ httpStatus = http.StatusBadRequest
+ return fmt.Errorf("Member %d don't have enough money (%d-%d)", member.Num, member.Balance, transaction.Total)
+ }
+ err = tx.Model(&Member{}).
+ Where("num = ?", transaction.MemberNum).
+ Update("balance", gorm.Expr("balance + ?", transaction.Total)).Error
+ if err != nil {
+ httpStatus = http.StatusNotAcceptable
+ fmt.Errorf("Can't update update member balance %d-%d: %v", member.Num, transaction.Total, err)
+ }
+
+ err = tx.Create(&transaction).Error
+ if err != nil {
+ httpStatus = http.StatusInternalServerError
+ return fmt.Errorf("Can't create transaction: %v\n%v", err, transaction)
+ }
+ return nil
+ })
+ return
}
--
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