WAL mode, extensions.

README.md

@@ -46,8 +46,9 @@ and WAL databases are not supported.
   - [x] nested transactions
   - [ ] incremental BLOB I/O
   - [ ] online backup
-  - [ ] session extension
   - [ ] snapshots
+  - [ ] session extension
+  - [ ] resumable bulk update
   - [ ] SQL functions
 - [ ] custom VFSes
   - [ ] read-only VFS, wrapping an [`io.ReaderAt`](https://pkg.go.dev/io#ReaderAt)

conn.go

@@ -267,17 +267,18 @@ func (c *Conn) sendInterrupt() {
 // Pragma executes a PRAGMA statement and returns any result as a string.
 //
 // https://www.sqlite.org/pragma.html
-func (c *Conn) Pragma(str string) string {
+func (c *Conn) Pragma(str string) []string {
 	stmt := c.MustPrepare(`PRAGMA ` + str)
 	defer stmt.Close()
 
-	if stmt.Step() {
-		return stmt.ColumnText(0)
+	var pragmas []string
+	for stmt.Step() {
+		pragmas = append(pragmas, stmt.ColumnText(0))
 	}
 	if err := stmt.Err(); err != nil {
 		panic(err)
 	}
-	return ""
+	return pragmas
 }
 
 func (c *Conn) error(rc uint64, sql ...string) error {

driver/driver.go

@@ -94,7 +94,7 @@ func (c conn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, er
 	if opts.ReadOnly {
 		c.txCommit = `
 			ROLLBACK;
-			PRAGMA query_only=` + c.conn.Pragma("query_only")
+			PRAGMA query_only=` + c.conn.Pragma("query_only")[0]
 		txBegin = `
 			BEGIN deferred;
 			PRAGMA query_only=on`

sqlite3/qsort.c

@@ -0,0 +1,14 @@
+#include <stddef.h>
+
+void qsort_r(void *, size_t, size_t,
+             int (*)(const void *, const void *, void *), void *);
+
+typedef int (*cmpfun)(const void *, const void *);
+
+static int wrapper_cmp(const void *v1, const void *v2, void *cmp) {
+  return ((cmpfun)cmp)(v1, v2);
+}
+
+void qsort(void *base, size_t nel, size_t width, cmpfun cmp) {
+  qsort_r(base, nel, width, wrapper_cmp, cmp);
+}

sqlite3/sqlite_cfg.h

@@ -28,18 +28,33 @@
 #define SQLITE_OMIT_AUTOINIT
 #define SQLITE_USE_ALLOCA
 
+// Because WASM does not support shared memory,
+// SQLite disables it for WASM builds.
+// We set the default locking mode to EXCLUSIVE instead.
+// https://www.sqlite.org/wal.html#noshm
+#undef SQLITE_OMIT_WAL
+#define SQLITE_DEFAULT_LOCKING_MODE 1
+
 // Recommended Extensions
 
-// #define SQLITE_ENABLE_MATH_FUNCTIONS 1
-// #define SQLITE_ENABLE_FTS3 1
-// #define SQLITE_ENABLE_FTS3_PARENTHESIS 1
-// #define SQLITE_ENABLE_FTS4 1
-// #define SQLITE_ENABLE_FTS5 1
-// #define SQLITE_ENABLE_RTREE 1
-// #define SQLITE_ENABLE_GEOPOLY 1
+#define SQLITE_ENABLE_MATH_FUNCTIONS 1
+#define SQLITE_ENABLE_JSON1 1
+#define SQLITE_ENABLE_FTS3 1
+#define SQLITE_ENABLE_FTS3_PARENTHESIS 1
+#define SQLITE_ENABLE_FTS4 1
+#define SQLITE_ENABLE_FTS5 1
+#define SQLITE_ENABLE_RTREE 1
+#define SQLITE_ENABLE_GEOPOLY 1
 
-// Need this to access WAL databases without the use of shared memory.
-#define SQLITE_DEFAULT_LOCKING_MODE 1
+// Snapshot
+// #define SQLITE_ENABLE_SNAPSHOT 1
+
+// Session Extension
+// #define SQLITE_ENABLE_SESSION 1
+// #define SQLITE_ENABLE_PREUPDATE_HOOK 1
+
+// Resumable Bulk Update Extension
+// #define SQLITE_ENABLE_RBU 1
 
 // Implemented in Go.
 int localtime_s(struct tm *const pTm, time_t const *const pTime);