Build fiddle with WASMFS OPFS support and attempt to use it if available. It does not work because of an inexplicable exception in Emscripten-generated code and perpetually-locked db, but it's not yet clear why.

FossilOrigin-Name: a16f0a46ec88c560f73d5664e4bf53fb5dd1a22e99a92c11b5c8d784816c3282

Makefile.in

@@ -1540,25 +1540,29 @@ fiddle_module_js = $(fiddle_dir)/fiddle-module.js
 #emcc_opt = -O2
 #emcc_opt = -O3
 emcc_opt = -Oz
+emcc_flags_opfs = -sWASMFS -pthread
 emcc_flags = $(emcc_opt) \
         -sALLOW_TABLE_GROWTH \
         -sABORTING_MALLOC \
         -sSTRICT_JS \
-        -sENVIRONMENT=web \
+        -sENVIRONMENT=web,worker \
         -sMODULARIZE \
         -sEXPORTED_RUNTIME_METHODS=@$(wasm_dir_abs)/EXPORTED_RUNTIME_METHODS.fiddle \
         -sDYNAMIC_EXECUTION=0 \
         --minify 0 \
         -I. $(SHELL_OPT) \
-        -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_UTF16 -DSQLITE_OMIT_DEPRECATED
+        -DSQLITE_THREADSAFE=0 \
-$(fiddle_module_js): Makefile sqlite3.c shell.c \
+        -DSQLITE_OMIT_UTF16 \
+        -DSQLITE_OMIT_DEPRECATED \
+        $(emcc_flags_opfs)
+$(fiddle_module_js): Makefile $(wasm_dir)/api/sqlite3-wasm.c shell.c \
     $(wasm_dir)/EXPORTED_RUNTIME_METHODS.fiddle \
     $(wasm_dir)/EXPORTED_FUNCTIONS.fiddle
 	emcc -o $@ $(emcc_flags) \
         -sEXPORT_NAME=initFiddleModule \
         -sEXPORTED_FUNCTIONS=@$(wasm_dir_abs)/EXPORTED_FUNCTIONS.fiddle \
         -DSQLITE_SHELL_FIDDLE \
-        sqlite3.c shell.c
+        $(wasm_dir)/api/sqlite3-wasm.c shell.c
 	gzip < $@ > $@.gz
 	gzip < $(fiddle_dir)/fiddle-module.wasm > $(fiddle_dir)/fiddle-module.wasm.gz
 $(fiddle_dir)/fiddle.js.gz: $(fiddle_dir)/fiddle.js

ext/wasm/EXPORTED_FUNCTIONS.fiddle

@@ -5,3 +5,5 @@ _fiddle_the_db
 _fiddle_db_arg
 _fiddle_db_filename
 _fiddle_reset_db
+_sqlite3_wasm_init_opfs
+_sqlite3_wasm_vfs_unlink

ext/wasm/GNUmakefile

@@ -168,12 +168,13 @@ emcc.cflags :=
 emcc.cflags += -std=c99 -fPIC
 # -------------^^^^^^^^ we currently need c99 for WASM-specific sqlite3 APIs.
 emcc.cflags += -I. -I$(dir.top) # $(SQLITE_OPT)
+emcc.cflags += -pthread
 
 ########################################################################
 # emcc flags specific to building the final .js/.wasm file...
 emcc.jsflags := -fPIC
 emcc.jsflags += --no-entry
-emcc.jsflags += -sENVIRONMENT=web
+emcc.jsflags += -sENVIRONMENT=web,worker
 emcc.jsflags += -sMODULARIZE
 emcc.jsflags += -sSTRICT_JS
 emcc.jsflags += -sDYNAMIC_EXECUTION=0
@@ -182,6 +183,7 @@ 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.jsflags += -sINITIAL_MEMORY=13107200
 #emcc.jsflags += -sTOTAL_STACK=4194304
 emcc.jsflags += -sEXPORT_NAME=sqlite3InitModule

ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api

@@ -68,5 +68,7 @@ _sqlite3_vfs_find
 _sqlite3_vfs_register
 _sqlite3_wasm_db_error
 _sqlite3_wasm_enum_json
+_sqlite3_wasm_init_opfs
+_sqlite3_wasm_vfs_unlink
 _malloc
 _free

ext/wasm/api/sqlite3-wasm.c

@@ -411,3 +411,49 @@ const char * sqlite3_wasm_enum_json(void){
 #undef outf
 #undef lenCheck
 }
+
+/*
+** This function is NOT part of the sqlite3 public API. It is strictly
+** for use by the sqlite project's own JS/WASM bindings.
+**
+** This function invokes the xDelete method of the default VFS,
+** passing on the given filename. If zName is NULL, no default VFS is
+** found, or it has no xDelete method, SQLITE_MISUSE is returned, else
+** the result of the xDelete() call is returned.
+*/
+int sqlite3_wasm_vfs_unlink(const char * zName){
+  int rc = SQLITE_MISUSE /* ??? */;
+  sqlite3_vfs * const pVfs = sqlite3_vfs_find(0);
+  if( zName && pVfs && pVfs->xDelete ){
+    rc = pVfs->xDelete(pVfs, zName, 1);
+  }
+  return rc;
+}
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten/wasmfs.h>
+#include <emscripten/console.h>
+/*
+** This function is NOT part of the sqlite3 public API. It is strictly
+** for use by the sqlite project's own JS/WASM bindings.
+**
+** This function should only be called if the JS side detects the
+** existence of the Origin-Private FileSystem (OPFS) APIs in the
+** client. The first time it is called, this function instantiates a
+** 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.
+*/
+int sqlite3_wasm_init_opfs(void){
+  static backend_t pOpfs = 0;
+  if( !pOpfs ){
+    pOpfs = wasmfs_create_opfs_backend();
+    if( pOpfs ){
+      emscripten_console_log("Created OPFS WASMFS backend.");
+    }
+  }
+  return pOpfs ? 0 : SQLITE_NOMEM;
+}
+#endif /* __EMSCRIPTEN__ */

ext/wasm/fiddle/fiddle-worker.js

@@ -235,7 +235,7 @@
           const oldName = Sqlite3Shell.dbFilename();
           Sqlite3Shell.exec('.open "/'+fn+'"');
           if(oldName && oldName !== fn){
-                    try{fiddleModule.FS.unlink(oldName);}
+            try{fiddleModule.fsUnlink(oldName);}
             catch(e){/*ignored*/}
           }
           stdout("Replaced DB with",fn+".");
@@ -296,6 +296,23 @@
      emcc ... -sMODULARIZE=1 -sEXPORT_NAME=initFiddleModule
   */
   initFiddleModule(fiddleModule).then(function(thisModule){
+    fiddleModule.fsUnlink = fiddleModule.cwrap('sqlite3_wasm_vfs_unlink','number',['string']);
+    (function initOpfs(){
+      if(!self.FileSystemHandle || !self.FileSystemDirectoryHandle
+         || !self.FileSystemFileHandle){
+        stdout("OPFS unavailable. All DB state is transient.");
+        return;
+      }
+      try {
+        if(0===fiddleModule.ccall('sqlite3_wasm_init_opfs', undefined)){
+          stdout("Initialized OPFS WASMFS backend.");
+        }else{
+          stderr("Initialization of OPFS WASMFS backend failed.");
+        }
+      }catch(e){
+        stderr("Apparently missing WASMFS:",e.message);
+      }
+    })();
     wMsg('fiddle-ready');
   });
 })();

ext/wasm/fiddle/fiddle.js

@@ -775,7 +775,7 @@ SELECT group_concat(rtrim(t),x'0a') as Mandelbrot FROM a;`}
             });
         })()/* example queries */;
 
-        SF.echo(null/*clear any output generated by the init process*/);
+        //SF.echo(null/*clear any output generated by the init process*/);
         if(window.jQuery && window.jQuery.terminal){
             /* Set up the terminal-style view... */
             const eTerm = window.jQuery('#view-terminal').empty();

manifest

@@ -1,9 +1,9 @@
-C Minor\swasm-related\sdoc\sclarification\sand\sremove\san\sobsolete\scode\scomment.
+C Build\sfiddle\swith\sWASMFS\sOPFS\ssupport\sand\sattempt\sto\suse\sit\sif\savailable.\sIt\sdoes\snot\swork\sbecause\sof\san\sinexplicable\sexception\sin\sEmscripten-generated\scode\sand\sperpetually-locked\sdb,\sbut\sit's\snot\syet\sclear\swhy.
-D 2022-08-12T17:55:18.237
+D 2022-08-12T17:57:09.467
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
-F Makefile.in eceb228bf7b48f961b59a508f42ffa1211bf0c4c5bc818807768cc7b187ab0c8
+F Makefile.in bada766cb44d202e405eca68e32bb3bcf11cad5b85c75f7fb16ac39e863f03f5
 F Makefile.linux-gcc f609543700659711fbd230eced1f01353117621dccae7b9fb70daa64236c5241
 F Makefile.msc d547a2fdba38a1c6cd1954977d0b0cc017f5f8fbfbc65287bf8d335808938016
 F README.md 8b8df9ca852aeac4864eb1e400002633ee6db84065bd01b78c33817f97d31f5e
@@ -472,11 +472,11 @@ F ext/session/test_session.c f433f68a8a8c64b0f5bc74dc725078f12483301ad4ae8375205
 F ext/userauth/sqlite3userauth.h 7f3ea8c4686db8e40b0a0e7a8e0b00fac13aa7a3
 F ext/userauth/user-auth.txt e6641021a9210364665fe625d067617d03f27b04
 F ext/userauth/userauth.c 7f00cded7dcaa5d47f54539b290a43d2e59f4b1eb5f447545fa865f002fc80cb
-F ext/wasm/EXPORTED_FUNCTIONS.fiddle 7fb73f7150ab79d83bb45a67d257553c905c78cd3d693101699243f36c5ae6c3
+F ext/wasm/EXPORTED_FUNCTIONS.fiddle db7a4602f043cf4a5e4135be3609a487f9f1c83f05778bfbdf93766be4541b96
 F ext/wasm/EXPORTED_RUNTIME_METHODS.fiddle a004bd5eeeda6d3b28d16779b7f1a80305bfe009dfc7f0721b042967f0d39d02
-F ext/wasm/GNUmakefile 5359a37fc13b68fad2259228590450339a0c59687744edd0db7bb93d3b1ae2b1
+F ext/wasm/GNUmakefile c354ad5ce3ecec80c28ed4314827adc10cbbc0ef47e028b0cfbdf336c4a98fa4
 F ext/wasm/README.md 4b00ae7c7d93c4591251245f0996a319e2651361013c98d2efb0b026771b7331
-F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api c5eaceabb9e759aaae7d3101a4a3e542f96ab2c99d89a80ce20ec18c23115f33
+F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api 77ef4bcf37e362b9ad61f9c175dfc0f1b3e571563fb311b96581cf422ee6a8ec
 F ext/wasm/api/EXPORTED_RUNTIME_METHODS.sqlite3-api 1ec3c73e7d66e95529c3c64ac3de2470b0e9e7fbf7a5b41261c367cf4f1b7287
 F ext/wasm/api/README.md b6d0fb64bfdf7bf9ce6938ea4104228f6f5bbef600f5d910b2f8c8694195988c
 F ext/wasm/api/post-js-footer.js b64319261d920211b8700004d08b956a6c285f3b0bba81456260a713ed04900c
@@ -488,16 +488,16 @@ F ext/wasm/api/sqlite3-api-opfs.js c93cdd14f81a26b3a64990515ee05c7e29827fbc8fba4
 F ext/wasm/api/sqlite3-api-prologue.js 0fb0703d2d8ac89fa2d4dd8f9726b0ea226b8708ac34e5b482df046e147de0eb
 F ext/wasm/api/sqlite3-api-worker.js 1124f404ecdf3c14d9f829425cef778cd683911a9883f0809a463c3c7773c9fd
 F ext/wasm/api/sqlite3-wasi.h 25356084cfe0d40458a902afb465df8c21fc4152c1d0a59b563a3fba59a068f9
-F ext/wasm/api/sqlite3-wasm.c 8585793ca8311c7a0618b7e00ed2b3729799c20664a51f196258576e3d475c9e
+F ext/wasm/api/sqlite3-wasm.c 0b3f56078f3e3806fb6dfbc756198d1634d3bfdbf3677c77702cf453c4ed336a
 F ext/wasm/api/sqlite3-worker.js 1325ca8d40129a82531902a3a077b795db2eeaee81746e5a0c811a04b415fa7f
 F ext/wasm/common/SqliteTestUtil.js e41a1406f18da9224523fad0c48885caf995b56956a5b9852909c0989e687e90
 F ext/wasm/common/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
 F ext/wasm/common/testing.css 572cf1ffae0b6eb7ca63684d3392bf350217a07b90e7a896e4fa850700c989b0
 F ext/wasm/common/whwasmutil.js 3d9deda1be718e2b10e2b6b474ba6ba857d905be314201ae5b3df5eef79f66aa
 F ext/wasm/fiddle/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
-F ext/wasm/fiddle/fiddle-worker.js 88bc2193a6cb6a3f04d8911bed50a4401fe6f277de7a71ba833865ab64a1b4ae
+F ext/wasm/fiddle/fiddle-worker.js c9d66230269cc26d33aa84501ae601c24f8697c3711be5d769c4c687bfcaba8f
 F ext/wasm/fiddle/fiddle.html 550c5aafce40bd218de9bf26192749f69f9b10bc379423ecd2e162bcef885c08
-F ext/wasm/fiddle/fiddle.js 812f9954cc7c4b191884ad171f36fcf2d0112d0a7ecfdf6087896833a0c079a8
+F ext/wasm/fiddle/fiddle.js bef4b30e078445a7cd2255fba07acd083aa1c3cc074a73b38ea847fd340f1adc
 F ext/wasm/jaccwabyt/jaccwabyt.js 99b424b4d467d4544e82615b58e2fe07532a898540bf9de2a985f3c21e7082b2
 F ext/wasm/jaccwabyt/jaccwabyt.md 447cc02b598f7792edaa8ae6853a7847b8178a18ed356afacbdbf312b2588106
 F ext/wasm/jaccwabyt/jaccwabyt_test.c 39e4b865a33548f943e2eb9dd0dc8d619a80de05d5300668e9960fff30d0d36f
@@ -1999,8 +1999,11 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 4c10b9b18feca82440273f8192fef951ad051bbfd8aad4d3c840cf6375130afd
+P 1b1f650a08da93da97ed3a96b9a3e4eac567472c266188c02a9bffe1cf620e53
-R 3e055b525bbc2100d8c4c001b630489b
+R a893d12114f31061d4e8d4e31dd72df1
+T *branch * fiddle-opfs
+T *sym-fiddle-opfs *
+T -sym-trunk * Cancelled\sby\sbranch.
 U stephan
-Z 4d766400503717808861a1e631c17801
+Z e55c83b0eefdc75c613c24a829476f39
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-1b1f650a08da93da97ed3a96b9a3e4eac567472c266188c02a9bffe1cf620e53
+a16f0a46ec88c560f73d5664e4bf53fb5dd1a22e99a92c11b5c8d784816c3282