User creation, DB transactions, createdb flag changes.

datastore/datastore.go

@@ -22,3 +22,9 @@ func NewDatastore(dbh modl.SqlExecutor) *Datastore {
 	d.Users = &usersStore{d}
 	return d
 }
+
+func NewMockDatastore() *Datastore {
+	return &Datastore{
+		Users: &models.MockUsersService{},
+	}
+}

datastore/db.go

@@ -51,3 +51,35 @@ func Drop() {
 	// TODO(mrd): raise errors.
 	DB.DropTables()
 }
+
+// transact calls fn in a DB transaction. If dbh is a transaction, then it just calls
+// the function. Otherwise, it begins a transaction, rolling back on failure and
+// committing on success.
+func transact(dbh modl.SqlExecutor, fn func(fbh modl.SqlExecutor) error) error {
+	var sharedTx bool
+	tx, sharedTx := dbh.(*modl.Transaction)
+	if !sharedTx {
+		var err error
+		tx, err = dbh.(*modl.DbMap).Begin()
+		if err != nil {
+			return err
+		}
+		defer func() {
+			if err != nil {
+				tx.Rollback()
+			}
+		}()
+	}
+
+	if err := fn(tx); err != nil {
+		return err
+	}
+
+	if !sharedTx {
+		if err := tx.Commit(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

datastore/users.go

@@ -1,6 +1,14 @@
 package datastore
 
-import "github.com/thermokarst/bactdb/models"
+import (
+	"fmt"
+	"math/rand"
+	"strings"
+	"time"
+
+	"github.com/jmoiron/modl"
+	"github.com/thermokarst/bactdb/models"
+)
 
 func init() {
 	DB.AddTableWithName(models.User{}, "users").SetKeys(true, "Id")
@@ -24,6 +32,46 @@ func (s *usersStore) Get(id int64) (*models.User, error) {
 	return users[0], nil
 }
 
+func (s *usersStore) Create(user *models.User) (bool, error) {
+	retries := 3
+	var wantRetry bool
+
+retry:
+	retries--
+	wantRetry = false
+	if retries == 0 {
+		return false, fmt.Errorf("failed to create user with username %q after retrying", user.UserName)
+	}
+
+	var created bool
+	err := transact(s.dbh, func(tx modl.SqlExecutor) error {
+		var existing []*models.User
+		if err := tx.Select(&existing, `SELECT * FROM users WHERE username=$1 LIMIT 1;`, user.UserName); err != nil {
+			return err
+		}
+		if len(existing) > 0 {
+			*user = *existing[0]
+			return nil
+		}
+
+		if err := tx.Insert(user); err != nil {
+			if strings.Contains(err.Error(), `violates unique constraint "username_idx"`) {
+				time.Sleep(time.Duration(rand.Intn(75)) * time.Millisecond)
+				wantRetry = true
+				return err
+			}
+			return err
+		}
+
+		created = true
+		return nil
+	})
+	if wantRetry {
+		goto retry
+	}
+	return created, err
+}
+
 func (s *usersStore) List(opt *models.UserListOptions) ([]*models.User, error) {
 	if opt == nil {
 		opt = &models.UserListOptions{}

datastore/users_test.go

@@ -12,6 +12,7 @@ func TestUsersStore_Get_db(t *testing.T) {
 
 	tx, _ := DB.Begin()
 	defer tx.Rollback()
+
 	// Test on a clean database
 	tx.Exec(`DELETE FROM users;`)
 	if err := tx.Insert(want); err != nil {
@@ -30,10 +31,32 @@ func TestUsersStore_Get_db(t *testing.T) {
 	}
 }
 
+func TestUsersStore_Create_db(t *testing.T) {
+	user := &models.User{Id: 1, UserName: "Test User"}
+
+	tx, _ := DB.Begin()
+	defer tx.Rollback()
+
+	// Test on a clean database
+	tx.Exec(`DELETE FROM users;`)
+
+	d := NewDatastore(tx)
+	created, err := d.Users.Create(user)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !created {
+		t.Error("!created")
+	}
+	if user.Id == 0 {
+		t.Error("want nonzero user.Id after submitting")
+	}
+}
+
 func TestUsersStore_List_db(t *testing.T) {
 	want := []*models.User{{Id: 1, UserName: "Test User"}}
 
-	// tx := DBH
 	tx, _ := DB.Begin()
 	defer tx.Rollback()