Explicitly set journal mode to WAL using PRAGMA

SQLITE_OPEN_WAL is only used in the vfs system. This change calls PRAGMA journal_mode=wal; if the SQLITE_OPEN_WAL flag is provided. Tests added for default and explicit behavior. Fixes #7
crawshaw · Apr 20, 2018 · ae8505e · ae8505e
1 parent d5b62ad
commit ae8505e
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diff --git a/sqlite.go b/sqlite.go
@@ -35,6 +35,10 @@ package sqlite
 // #include <stdlib.h>
 // #include <string.h>
 //
+// // Set typedefs for calling sqlite3_exec()
+// typedef int (*_sqlite_callback)(void*,int,char**,char**);
+// typedef char ** charPtrPtr;
+//
 // // Use a helper function here to avoid the cgo pointer detection
 // // logic treating SQLITE_TRANSIENT as a Go pointer.
 // static int transient_bind_text(sqlite3_stmt* stmt, int col, char* p, int n) {
@@ -144,6 +148,20 @@ func openConn(path string, flags OpenFlags) (*Conn, error) {
 		}
 	})
 
+	if flags&SQLITE_OPEN_WAL > 0 {
+		pragma := C.CString("PRAGMA journal_mode=wal")
+		defer C.free(unsafe.Pointer(pragma))
+		res = C.sqlite3_exec(conn.conn, pragma, C._sqlite_callback(nil), unsafe.Pointer(nil), C.charPtrPtr(nil))
+		if res != 0 {
+			extres := C.sqlite3_extended_errcode(conn.conn)
+			if extres != 0 {
+				res = extres
+			}
+			C.sqlite3_close_v2(conn.conn)
+			return nil, reserr("OpenConn", path, "", res)
+		}
+	}
+
 	return conn, nil
 }
 

diff --git a/sqlite_test.go b/sqlite_test.go
@@ -16,6 +16,9 @@ package sqlite_test
 
 import (
 	"context"
+	"io/ioutil"
+	"os"
+	"path/filepath"
 	"reflect"
 	"strings"
 	"testing"
@@ -353,3 +356,51 @@ func TestExtendedCodes(t *testing.T) {
 		t.Errorf("got err=%s, want %s", got, want)
 	}
 }
+
+func TestJournalMode(t *testing.T) {
+	dir, err := ioutil.TempDir("", "crawshaw.io")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	tests := []struct {
+		mode  string
+		flags sqlite.OpenFlags
+	}{
+		{
+			"delete",
+			sqlite.SQLITE_OPEN_READWRITE | sqlite.SQLITE_OPEN_CREATE,
+		},
+		{
+			"wal",
+			sqlite.SQLITE_OPEN_READWRITE | sqlite.SQLITE_OPEN_CREATE | sqlite.SQLITE_OPEN_WAL,
+		},
+		{
+			"wal",
+			0,
+		},
+	}
+
+	for _, test := range tests {
+		dbFile := filepath.Join(dir, "test-"+test.mode+".db")
+		c, err := sqlite.OpenConn(dbFile, test.flags)
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer func() {
+			if err := c.Close(); err != nil {
+				t.Error(err)
+			}
+		}()
+		stmt := c.Prep("PRAGMA journal_mode;")
+		if hasRow, err := stmt.Step(); err != nil {
+			t.Fatal(err)
+		} else if !hasRow {
+			t.Error("PRAGMA journal_mode: has no row")
+		}
+		if got := stmt.GetText("journal_mode"); got != test.mode {
+			t.Errorf("journal_mode not set properly, got: %s, want: %s", got, test.mode)
+		}
+	}
+}