MemoryVFS journal.

sqlite3/deserialize.patch

@@ -0,0 +1,20 @@
+--- sqlite3.c.orig
++++ sqlite3.c
+@@ -60425,7 +60425,7 @@
+   int rc = SQLITE_OK;      /* Return code */
+   int tempFile = 0;        /* True for temp files (incl. in-memory files) */
+   int memDb = 0;           /* True if this is an in-memory file */
+-#ifndef SQLITE_OMIT_DESERIALIZE
++#if 1
+   int memJM = 0;           /* Memory journal mode */
+ #else
+ # define memJM 0
+@@ -60628,7 +60628,7 @@
+     int fout = 0;                    /* VFS flags returned by xOpen() */
+     rc = sqlite3OsOpen(pVfs, pPager->zFilename, pPager->fd, vfsFlags, &fout);
+     assert( !memDb );
+-#ifndef SQLITE_OMIT_DESERIALIZE
++#if 1
+     pPager->memVfs = memJM = (fout&SQLITE_OPEN_MEMORY)!=0;
+ #endif
+     readOnly = (fout&SQLITE_OPEN_READONLY)!=0;

sqlite3/download.sh

@@ -8,6 +8,9 @@ unzip -d . sqlite-amalgamation-*.zip
 mv sqlite-amalgamation-*/sqlite3* .
 rm -rf sqlite-amalgamation-*
 
+patch < vfs_find.patch
+patch < deserialize.patch
+
 cd ext/
 curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/decimal.c"
 curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/uint.c"

sqlite3/sqlite_cfg.h

@@ -30,6 +30,9 @@
 
 // Other Options
 #define SQLITE_ALLOW_URI_AUTHORITY
+#define SQLITE_ENABLE_BATCH_ATOMIC_WRITE
+#define SQLITE_ENABLE_ATOMIC_WRITE
+#define SQLITE_OMIT_DESERIALIZE
 
 // Because WASM does not support shared memory,
 // SQLite disables WAL for WASM builds.
@@ -55,16 +58,5 @@
 // #define SQLITE_ENABLE_SESSION
 // #define SQLITE_ENABLE_PREUPDATE_HOOK
 
-// https://stackoverflow.com/a/50616684
-#define SECOND(...) SECOND_I(__VA_ARGS__, , )
-#define SECOND_I(A, B, ...) B
-#define GLUE(A, B) GLUE_I(A, B)
-#define GLUE_I(A, B) A##_##B
-#define CREATE_REPLACER(A) SECOND(GLUE(A, __LINE__), A)
-#define REPLACE_AT_LINE(A) , A
-
 // Implemented in vfs.c.
-int localtime_s(struct tm *const pTm, time_t const *const pTime);
-
-#define sqlite3_vfs_find CREATE_REPLACER(sqlite3_vfs_find_wrapper)
-#define sqlite3_vfs_find_wrapper_25397 REPLACE_AT_LINE(sqlite3_vfs_find)
+int localtime_s(struct tm *const pTm, time_t const *const pTime);

sqlite3/vfs.c

@@ -87,8 +87,7 @@ int localtime_s(struct tm *const pTm, time_t const *const pTime) {
   return go_localtime(pTm, (sqlite3_int64)*pTime);
 }
 
-#undef sqlite3_vfs_find
-sqlite3_vfs *sqlite3_vfs_find_wrapper(const char *zVfsName) {
+sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName) {
   if (zVfsName) {
     static sqlite3_vfs *go_vfs_list;
     sqlite3_vfs *found = NULL;
@@ -130,7 +129,7 @@ sqlite3_vfs *sqlite3_vfs_find_wrapper(const char *zVfsName) {
       return go_vfs_list;
     }
   }
-  return sqlite3_vfs_find(zVfsName);
+  return sqlite3_vfs_find_orig(zVfsName);
 }
 
 static_assert(offsetof(struct go_file, handle) == 4, "Unexpected offset");

sqlite3/vfs_find.patch

@@ -0,0 +1,11 @@
+--- sqlite3.c.orig
++++ sqlite3.c
+@@ -25394,7 +25394,7 @@
+ ** Locate a VFS by name.  If no name is given, simply return the
+ ** first VFS on the list.
+ */
+-SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
++SQLITE_API sqlite3_vfs *sqlite3_vfs_find_orig(const char *zVfs){
+   sqlite3_vfs *pVfs = 0;
+ #if SQLITE_THREADSAFE
+   sqlite3_mutex *mutex;

sqlite3vfs/example_test.go

@@ -22,7 +22,7 @@ func ExampleMemoryVFS_embed() {
 		"test.db": sqlite3vfs.NewMemoryDB(testDB),
 	})
 
-	db, err := sql.Open("sqlite3", "file:test.db?vfs=memory&_pragma=journal_mode(memory)")
+	db, err := sql.Open("sqlite3", "file:test.db?vfs=memory")
 	if err != nil {
 		log.Fatal(err)
 	}

sqlite3vfs/memory.go

@@ -21,7 +21,7 @@ func (vfs MemoryVFS) Open(name string, flags OpenFlag) (File, OpenFlag, error) {
 		return &memoryFile{
 			MemoryDB: db,
 			readOnly: flags&OPEN_READONLY != 0,
-		}, flags, nil
+		}, flags | OPEN_MEMORY, nil
 	}
 	return nil, flags, _CANTOPEN
 }
@@ -45,8 +45,7 @@ const memSectorSize = 65536
 
 // A MemoryDB is a [MemoryVFS] database.
 //
-// A MemoryDB is safe to access concurrently from multiple SQLite connections.
-// It requires journal mode MEMORY or OFF.
+// A MemoryDB is safe to access concurrently through multiple SQLite connections.
 type MemoryDB struct {
 	MaxSize int64
 
@@ -60,16 +59,16 @@ type MemoryDB struct {
 	shared   int
 }
 
-// NewMemoryDB creates a new MemoryDB using buf as its initial contents.
-// The new MemoryDB takes ownership of buf, and the caller should not use buf after this call.
-func NewMemoryDB(buf []byte) *MemoryDB {
+// NewMemoryDB creates a new MemoryDB using mem as its initial contents.
+// The new MemoryDB takes ownership of mem, and the caller should not use mem after this call.
+func NewMemoryDB(mem []byte) *MemoryDB {
 	m := new(MemoryDB)
-	m.size = int64(len(buf))
+	m.size = int64(len(mem))
 
 	sectors := divRoundUp(m.size, memSectorSize)
 	m.data = make([]*[memSectorSize]byte, sectors)
 	for i := range m.data {
-		sector := buf[i*memSectorSize:]
+		sector := mem[i*memSectorSize:]
 		if len(sector) >= memSectorSize {
 			m.data[i] = (*[memSectorSize]byte)(sector)
 		} else {

sqlite3vfs/tests/mptest/testdata/mptest.wasm

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:aafb873c26d32dbf7498e4c4dd243eb6411c056432818121463d8cb49bc15f70
-size 1479293
+oid sha256:fab92aa470cc311d0cda364e21594ac57f25efce679920f65dd681f027ec9629
+size 1477051

sqlite3vfs/tests/speedtest1/testdata/speedtest1.wasm

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:2638f5458f93b60f97006456f60e3e294cffb9ac22b20dba748fbd12e34f056d
-size 1515841
+oid sha256:61adff257e8f6035c3fc7fd6371f4ac14c66ae5622202f6567244d18757375b2
+size 1513558

tests/db_test.go

@@ -24,7 +24,7 @@ func TestDB_VFS(t *testing.T) {
 		"test.db": &sqlite3vfs.MemoryDB{},
 	})
 	defer sqlite3vfs.Unregister("memvfs")
-	testDB(t, "file:test.db?vfs=memvfs&_pragma=journal_mode(memory)")
+	testDB(t, "file:test.db?vfs=memvfs")
 }
 
 func testDB(t *testing.T, name string) {

tests/vfs_test.go

@@ -31,34 +31,13 @@ func TestMemoryVFS_Open_notfound(t *testing.T) {
 	}
 }
 
-func TestMemoryVFS_Open_journal(t *testing.T) {
-	sqlite3vfs.Register("memory", sqlite3vfs.MemoryVFS{
-		"test.db": &sqlite3vfs.MemoryDB{},
-	})
-	defer sqlite3vfs.Unregister("memory")
-
-	db, err := sqlite3.Open("file:test.db?vfs=memory")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer db.Close()
-
-	err = db.Exec(`CREATE TABLE IF NOT EXISTS test (col)`)
-	if err == nil {
-		t.Error("want error")
-	}
-	if !errors.Is(err, sqlite3.CANTOPEN) {
-		t.Errorf("got %v, want sqlite3.CANTOPEN", err)
-	}
-}
-
 func TestMemoryVFS_Open_errors(t *testing.T) {
 	sqlite3vfs.Register("memory", sqlite3vfs.MemoryVFS{
 		"test.db": &sqlite3vfs.MemoryDB{MaxSize: 65536},
 	})
 	defer sqlite3vfs.Unregister("memory")
 
-	db, err := sqlite3.Open("file:test.db?vfs=memory&_pragma=journal_mode(memory)")
+	db, err := sqlite3.Open("file:test.db?vfs=memory")
 	if err != nil {
 		t.Fatal(err)
 	}