From 9a8de3ad13137f35e8c918756e6fc5dde0a020bf Mon Sep 17 00:00:00 2001
From: Nuno Cruces <ncruces@users.noreply.github.com>
Date: Thu, 1 Jun 2023 15:41:20 +0100
Subject: [PATCH] Enable memdb on speedtest1.

---
 sqlite3memdb/memdb.go                          | 10 +++++++++-
 sqlite3vfs/tests/speedtest1/speedtest1_test.go |  1 +
 sqlite3vfs/vfs.go                              |  2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/sqlite3memdb/memdb.go b/sqlite3memdb/memdb.go
index 3af79bc..8829219 100644
--- a/sqlite3memdb/memdb.go
+++ b/sqlite3memdb/memdb.go
@@ -14,7 +14,14 @@ import (
 type vfs struct{}
 
 func (vfs) Open(name string, flags sqlite3vfs.OpenFlag) (sqlite3vfs.File, sqlite3vfs.OpenFlag, error) {
-	if flags&sqlite3vfs.OPEN_MAIN_DB == 0 {
+	// Allowed file types:
+	// - databases, which only do page aligned reads/writes;
+	// - temp journals, used by the sorter, which does the same.
+	const types = sqlite3vfs.OPEN_MAIN_DB |
+		sqlite3vfs.OPEN_TRANSIENT_DB |
+		sqlite3vfs.OPEN_TEMP_DB |
+		sqlite3vfs.OPEN_TEMP_JOURNAL
+	if flags&types == 0 {
 		return nil, flags, sqlite3.CANTOPEN
 	}
 
@@ -54,6 +61,7 @@ func (vfs) FullPathname(name string) (string, error) {
 	return name, nil
 }
 
+// Must be a multiple of 64K (the largest page size).
 const sectorSize = 65536
 
 type dbase struct {
diff --git a/sqlite3vfs/tests/speedtest1/speedtest1_test.go b/sqlite3vfs/tests/speedtest1/speedtest1_test.go
index ea13fff..39e3e98 100644
--- a/sqlite3vfs/tests/speedtest1/speedtest1_test.go
+++ b/sqlite3vfs/tests/speedtest1/speedtest1_test.go
@@ -20,6 +20,7 @@ import (
 	"github.com/tetratelabs/wazero/experimental"
 	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
 
+	_ "github.com/ncruces/go-sqlite3/sqlite3memdb"
 	"github.com/ncruces/go-sqlite3/sqlite3vfs"
 )
 
diff --git a/sqlite3vfs/vfs.go b/sqlite3vfs/vfs.go
index 79bc6a4..c17c95b 100644
--- a/sqlite3vfs/vfs.go
+++ b/sqlite3vfs/vfs.go
@@ -219,7 +219,7 @@ func vfsRead(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfs
 	if n == int(iAmt) {
 		return _OK
 	}
-	if n == 0 && err != io.EOF {
+	if err != io.EOF {
 		return vfsErrorCode(err, _IOERR_READ)
 	}
 	clear(buf[n:])