Cleanups in the wasmfs/opfs integration but disable it in order to get the build into a known-working state before continuing with experimentation.

FossilOrigin-Name: 41045be752a5bd7966849638f3ca56f4905308df70f79f2cb6196ca7dce9d525

1 files changed, 22 insertions, 5 deletions

diff --git a/ext/wasm/api/sqlite3-wasm.c b/ext/wasm/api/sqlite3-wasm.c
index 30a9dafeb..487baecf1 100644
--- a/ext/wasm/api/sqlite3-wasm.c
+++ b/ext/wasm/api/sqlite3-wasm.c
@@ -430,7 +430,7 @@ int sqlite3_wasm_vfs_unlink(const char * zName){
   return rc;
 }
 
-#ifdef __EMSCRIPTEN__
+#if defined(__EMSCRIPTEN__) && defined(SQLITE_WASM_OPFS)
 #include <emscripten/wasmfs.h>
 #include <emscripten/console.h>
 /*
@@ -443,17 +443,34 @@ int sqlite3_wasm_vfs_unlink(const char * zName){
 ** WASMFS backend impl for OPFS. On success, subsequent calls are
 ** no-ops.
 **
-** Returns 0 on success, SQLITE_NOMEM if intantiation of the backend
-** object fails.
+** Returns 0 on success, SQLITE_NOMEM if instantiation of the backend
+** object fails, SQLITE_IOERR if mkdir() of the "/persistent" dir in
+** the virtual FS fails. In builds compiled without SQLITE_WASM_OPFS
+** defined, SQLITE_NOTFOUND is returned without side effects.
 */
 int sqlite3_wasm_init_opfs(void){
   static backend_t pOpfs = 0;
+  static const char * zDir = "/persistent";
   if( !pOpfs ){
     pOpfs = wasmfs_create_opfs_backend();
     if( pOpfs ){
-      emscripten_console_log("Created OPFS WASMFS backend.");
+      emscripten_console_log("Created WASMFS OPFS backend.");
     }
   }
+  /** It's not enough to instantiate the backend. We have to create a
+      mountpoint in the VFS and attach the backend to it. */
+  if( pOpfs && 0!=access(zDir, F_OK) ){
+    /* mkdir() simply hangs when called from fiddle app. Cause is
+       not yet determined but the hypothesis is an init-order
+       issue. */
+    const int rc = wasmfs_create_directory(zDir, 0777, pOpfs);
+    emscripten_console_log(rc ? "OPFS mkdir failed." : "OPFS mkdir ok.");
+    if(rc) return SQLITE_IOERR;
+  }
   return pOpfs ? 0 : SQLITE_NOMEM;
 }
-#endif /* __EMSCRIPTEN__ */
+#else
+int sqlite3_wasm_init_opfs(void){
+  return SQLITE_NOTFOUND;
+}
+#endif /* __EMSCRIPTEN__ && SQLITE_WASM_OPFS */