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

ext/wasm/GNUmakefile

@@ -127,9 +127,9 @@ sqlite3-api.jses := \
   $(dir.jacc)/jaccwabyt.js \
   $(dir.api)/sqlite3-api-glue.js \
   $(dir.api)/sqlite3-api-oo1.js \
-  $(dir.api)/sqlite3-api-worker.js \
-  $(dir.api)/sqlite3-api-opfs.js \
-  $(dir.api)/sqlite3-api-cleanup.js
+  $(dir.api)/sqlite3-api-worker.js
+#sqlite3-api.jses += $(dir.api)/sqlite3-api-opfs.js 
+sqlite3-api.jses += $(dir.api)/sqlite3-api-cleanup.js
 
 sqlite3-api.js := $(dir.api)/sqlite3-api.js
 CLEAN_FILES += $(sqlite3-api.js)
@@ -174,7 +174,6 @@ emcc.cflags += -pthread
 # emcc flags specific to building the final .js/.wasm file...
 emcc.jsflags := -fPIC
 emcc.jsflags += --no-entry
-emcc.jsflags += -sENVIRONMENT=web,worker
 emcc.jsflags += -sMODULARIZE
 emcc.jsflags += -sSTRICT_JS
 emcc.jsflags += -sDYNAMIC_EXECUTION=0
@@ -183,7 +182,12 @@ emcc.jsflags += -sEXPORTED_FUNCTIONS=@$(dir.wasm)/EXPORTED_FUNCTIONS.api
 emcc.jsflags += -sEXPORTED_RUNTIME_METHODS=FS,wasmMemory # wasmMemory==>for -sIMPORTED_MEMORY
 emcc.jsflags += -sUSE_CLOSURE_COMPILER=0
 emcc.jsflags += -sIMPORTED_MEMORY
-emcc.jsflags += -pthread -sWASMFS
+emcc.environment := -sENVIRONMENT=web
+ifeq (0,1)
+  emcc.jsflags += -pthread -sWASMFS -sPTHREAD_POOL_SIZE=2
+  emcc.environment := $(emcc.environment),worker
+endif
+emcc.jsflags += $(emcc.environment)
 #emcc.jsflags += -sINITIAL_MEMORY=13107200
 #emcc.jsflags += -sTOTAL_STACK=4194304
 emcc.jsflags += -sEXPORT_NAME=sqlite3InitModule
@@ -235,11 +239,14 @@ $(dir.api)/sqlite3-wasm.o: $(dir.top)/sqlite3.c
 $(dir.api)/wasm_util.o: emcc.cflags += $(SQLITE_OPT)
 sqlite3.wasm.c := $(dir.api)/sqlite3-wasm.c \
     $(dir.jacc)/jaccwabyt_test.c
-# ^^^ FIXME (how?): jaccwabyt_test.c is only needed for the test
-# apps. However, we want to test the release builds with those apps,
-# so we cannot simply elide that file in release builds. That
-# component is critical to the VFS bindings so needs to be tested
-# along with the core APIs.
+# ^^^ FIXME (how?): jaccwabyt_test.c is only needed for the test apps,
+# so we don't really want to include it in release builds. However, we
+# want to test the release builds with those apps, so we cannot simply
+# elide that file in release builds. That component is critical to the
+# VFS bindings so needs to be tested along with the core APIs.
+ifneq (,$(filter -sWASMFS,$(emcc.jsflags)))
+  $(dir.api)/sqlite3-wasm.o: emcc.cflags+=-DSQLITE_WASM_OPFS
+endif
 define WASM_C_COMPILE
 $(1).o := $$(subst .c,.o,$(1))
 sqlite3.wasm.obj += $$($(1).o)

ext/wasm/api/sqlite3-api-prologue.js

@@ -576,6 +576,55 @@ self.sqlite3ApiBootstrap = function(config){
       ["sqlite3_total_changes64", "i64", ["sqlite3*"]]
   ];
 
+  /** State for sqlite3_web_persistent_dir(). */
+  let __persistentDir;
+  /**
+     An experiment. Do not use.
+
+     If the wasm environment has a persistent storage directory,
+     its path is returned by this function. If it does not then
+     it returns one of:
+
+     - `undefined` if initIfNeeded is false and this function has
+       never been called before.
+
+     - `""` if no persistent storage is available.
+
+     Note that in both cases the return value is falsy.
+  */
+  capi.sqlite3_web_persistent_dir = function(initIfNeeded=true){
+    if(undefined !== __persistentDir) return __persistentDir;
+    else if(!initIfNeeded) return;
+    // If we have no OPFS, there is no persistent dir
+    if(!self.FileSystemHandle || !self.FileSystemDirectoryHandle
+       || !self.FileSystemFileHandle){
+      return __persistentDir = "";
+    }
+    try{
+      if(0===this.wasm.xCall('sqlite3_wasm_init_opfs')){
+        /** OPFS does not support locking and will trigger errors if
+            we try to lock. We don't _really_ want to
+            _unconditionally_ install a non-locking sqlite3 VFS as the
+            default, but we do so here for simplicy's sake for the
+            time being. That said: locking is a no-op on all of the
+            current WASM storage, so this isn't (currently) as bad as
+            it may initially seem. */
+        const pVfs = this.sqlite3_vfs_find("unix-none");
+        if(pVfs){
+          this.sqlite3_vfs_register(pVfs,1);
+          //warn("Installed 'unix-none' as the default sqlite3 VFS.");
+        }
+        return __persistentDir =
+          "/persistent" /* name is hard-coded in sqlite3_wasm_init_opfs()!*/;
+      }else{
+        return __persistentDir = "";
+      }
+    }catch(e){
+      // sqlite3_wasm_init_opfs() is not available
+      return __persistentDir = "";
+    }
+  }.bind(capi);
+
   /* The remainder of the API will be set up in later steps. */
   return {
     capi,

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 */

ext/wasm/testing1.js

@@ -19,7 +19,8 @@
   const toss = function(...args){throw new Error(args.join(' '))};
   const debug = console.debug.bind(console);
   const eOutput = document.querySelector('#test-output');
-  const log = console.log.bind(console)
+  const log = console.log.bind(console),
+        warn = console.warn.bind(console);
   const logHtml = function(...args){
     log.apply(this, args);
     const ln = document.createElement('div');
@@ -1012,7 +1013,7 @@
           wasm = capi.wasm;
     log("Loaded module:",capi.sqlite3_libversion(), capi.sqlite3_sourceid());
     log("Build options:",wasm.compileOptionUsed());
-
+    capi.sqlite3_web_persistent_dir()/*will install OPFS if available, plus a and non-locking VFS*/;
     if(1){
       /* Let's grab those last few lines of test coverage for
          sqlite3-api.js... */

ext/wasm/testing2.js

@@ -20,7 +20,7 @@
     id: undefined
   };
   const eOutput = document.querySelector('#test-output');
-  const log = console.log.bind(console)
+  const log = console.log.bind(console);
   const logHtml = function(cssClass,...args){
     log.apply(this, args);
     const ln = document.createElement('div');