OPFS VFSes: remove the on-open() pragma calls, as those (A) already reflected the build-time default settings and (B) they made it illegal to run locking_mode=exclusive, which is a requirement for WAL mode without shared memory. Modify part of the test suite to demonstrate that the SAHPool VFS can run in WAL mode so long as locking_mode=exclusive is used.

FossilOrigin-Name: 19cd8e2b056d7842ee39afb7160c901c9dc55a5bac8049cb0b5246210f6b920d

ext/wasm/api/sqlite3-api-oo1.c-pp.js

@@ -79,14 +79,6 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
           }
         }.bind({counter: 0}));
 
-  /**
-     A map of sqlite3_vfs pointers to SQL code or a callback function
-     to run when the DB constructor opens a database with the given
-     VFS. In the latter case, the call signature is (theDbObject,sqlite3Namespace)
-     and the callback is expected to throw on error.
-  */
-  const __vfsPostOpenSql = Object.create(null);
-
 //#if enable-see
   /**
      Converts ArrayBuffer or Uint8Array ba into a string of hex
@@ -279,7 +271,7 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
       // Check for per-VFS post-open SQL/callback...
       const pVfs = capi.sqlite3_js_db_vfs(pDb)
             || toss3("Internal error: cannot get VFS for new db handle.");
-      const postInitSql = __vfsPostOpenSql[pVfs];
+      const postInitSql = __vfsPostOpenCallback[pVfs];
       if(postInitSql){
         /**
            Reminder: if this db is encrypted and the client did _not_ pass
@@ -302,19 +294,39 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
     }
   };
 
+
   /**
-     Sets SQL which should be exec()'d on a DB instance after it is
+     A map of sqlite3_vfs pointers to SQL code or a callback function
-     opened with the given VFS pointer. The SQL may be any type
+     to run when the DB constructor opens a database with the given
-     supported by the "string:flexible" function argument conversion.
+     VFS. In the latter case, the call signature is
-     Alternately, the 2nd argument may be a function, in which case it
+     (theDbObject,sqlite3Namespace) and the callback is expected to
-     is called with (theOo1DbObject,sqlite3Namespace) at the end of
+     throw on error.
-     the DB() constructor. The function must throw on error, in which
-     case the db is closed and the exception is propagated.  This
-     function is intended only for use by DB subclasses or sqlite3_vfs
-     implementations.
   */
-  dbCtorHelper.setVfsPostOpenSql = function(pVfs, sql){
+  const __vfsPostOpenCallback = Object.create(null);
-    __vfsPostOpenSql[pVfs] = sql;
+
+  /**
+     Sets a callback which should be called after a db is opened with
+     the given sqlite3_vfs pointer. The 2nd argument must be a
+     function, which gets called with
+     (theOo1DbObject,sqlite3Namespace) at the end of the DB()
+     constructor. The function must throw on error, in which case the
+     db is closed and the exception is propagated.  This function is
+     intended only for use by DB subclasses or sqlite3_vfs
+     implementations.
+
+     Prior to 2024-07-22, it was legal to pass SQL code as the second
+     argument, but that can interfere with a client's ability to run
+     pragmas which must be run before anything else, namely (pragma
+     locking_mode=exclusive) for use with WAL mode.  That capability
+     had only ever been used as an internal detail of the two OPFS
+     VFSes, and they no longer use it that way.
+  */
+  dbCtorHelper.setVfsPostOpenCallback = function(pVfs, callback){
+    if( !(callback instanceof Function)){
+      toss3("dbCtorHelper.setVfsPostOpenCallback() should not be used with "+
+            "a non-function argument.",arguments);
+    }
+    __vfsPostOpenCallback[pVfs] = callback;
   };
 
   /**

ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js

@@ -78,8 +78,7 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
         capi.SQLITE_OPEN_MAIN_DB |
         capi.SQLITE_OPEN_MAIN_JOURNAL |
         capi.SQLITE_OPEN_SUPER_JOURNAL |
-        capi.SQLITE_OPEN_WAL /* noting that WAL support is
+        capi.SQLITE_OPEN_WAL;
-                                unavailable in the WASM build.*/;
 
   /** Subdirectory of the VFS's space where "opaque" (randomly-named)
       files are stored. Changing this effectively invalidates the data
@@ -1280,16 +1279,6 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
           };
           OpfsSAHPoolDb.prototype = Object.create(oo1.DB.prototype);
           poolUtil.OpfsSAHPoolDb = OpfsSAHPoolDb;
-          oo1.DB.dbCtorHelper.setVfsPostOpenSql(
-            theVfs.pointer,
-            function(oo1Db, sqlite3){
-              sqlite3.capi.sqlite3_exec(oo1Db, [
-                /* See notes in sqlite3-vfs-opfs.js */
-                "pragma journal_mode=DELETE;",
-                "pragma cache_size=-16384;"
-              ], 0, 0, 0);
-            }
-          );
         }/*extend sqlite3.oo1*/
         thePool.log("VFS initialized.");
         return poolUtil;

ext/wasm/api/sqlite3-vfs-opfs.c-pp.js

@@ -1288,40 +1288,13 @@ const installOpfsVfs = function callee(options){
       OpfsDb.prototype = Object.create(sqlite3.oo1.DB.prototype);
       sqlite3.oo1.OpfsDb = OpfsDb;
       OpfsDb.importDb = opfsUtil.importDb;
-      sqlite3.oo1.DB.dbCtorHelper.setVfsPostOpenSql(
+      sqlite3.oo1.DB.dbCtorHelper.setVfsPostOpenCallback(
         opfsVfs.pointer,
         function(oo1Db, sqlite3){
           /* Set a relatively high default busy-timeout handler to
              help OPFS dbs deal with multi-tab/multi-worker
              contention. */
           sqlite3.capi.sqlite3_busy_timeout(oo1Db, 10000);
-          sqlite3.capi.sqlite3_exec(oo1Db, [
-            /* As of July 2023, the PERSIST journal mode on OPFS is
-               somewhat slower than DELETE or TRUNCATE (it was faster
-               before Chrome version 108 or 109). TRUNCATE and DELETE
-               have very similar performance on OPFS.
-
-               Roy Hashimoto notes that TRUNCATE and PERSIST modes may
-               decrease OPFS concurrency because multiple connections
-               can open the journal file in those modes:
-
-               https://github.com/rhashimoto/wa-sqlite/issues/68
-
-               Given that, and the fact that testing has not revealed
-               any appreciable difference between performance of
-               TRUNCATE and DELETE modes on OPFS, we currently (as of
-               2023-07-13) default to DELETE mode.
-            */
-            "pragma journal_mode=DELETE;",
-            /*
-              This vfs benefits hugely from cache on moderate/large
-              speedtest1 --size 50 and --size 100 workloads. We
-              currently rely on setting a non-default cache size when
-              building sqlite3.wasm. If that policy changes, the cache
-              can be set here.
-            */
-            "pragma cache_size=-16384;"
-          ], 0, 0, 0);
         }
       );
     }/*extend sqlite3.oo1*/

ext/wasm/tester1.c-pp.js

@@ -3113,11 +3113,25 @@ globalThis.sqlite3InitModule = sqlite3InitModule;
         T.assert(db instanceof sqlite3.oo1.DB)
           .assert(1 === u1.getFileCount());
         db.exec([
+          'pragma locking_mode=exclusive;',
+          'pragma journal_mode=wal;'
+          /* WAL mode only works in this VFS if locking_mode=exclusive
+             is invoked prior to the first db access, as this build
+             does not have the shared-memory APIs needed for WAL without
+             exclusive-mode locking. See:
+
+             https://sqlite.org/wal.html#use_of_wal_without_shared_memory
+
+             Note that WAL mode here DOES NOT add any concurrency capabilities
+             to this VFS, but it MAY provide slightly improved performance
+             over the other journaling modes.
+          */,
           'create table t(a);',
           'insert into t(a) values(1),(2),(3)'
         ]);
-        T.assert(1 === u1.getFileCount());
+        T.assert(2 === u1.getFileCount() /* one is the journal file */)
-        T.assert(3 === db.selectValue('select count(*) from t'));
+          .assert(3 === db.selectValue('select count(*) from t'))
+          .assert('wal'===db.selectValue('pragma journal_mode'));
         db.close();
         T.assert(1 === u1.getFileCount());
         db = new u2.OpfsSAHPoolDb(dbName);
@@ -3137,6 +3151,7 @@ globalThis.sqlite3InitModule = sqlite3InitModule;
             .assert( dbytes.byteLength == nWrote );
           let db2 = new u1.OpfsSAHPoolDb(dbName2);
           T.assert(db2 instanceof sqlite3.oo1.DB)
+            //.assert('wal' == db2.selectValue("pragma journal_mode=WAL"))
             .assert(3 === db2.selectValue('select count(*) from t'));
           db2.close();
           T.assert(true === u1.unlink(dbName2))

manifest

@@ -1,5 +1,5 @@
-C wasm\sbuild:\sresolve\sa\scircular\sdep\sand\sdo\ssome\sminor\stidying\sup.
+C OPFS\sVFSes:\sremove\sthe\son-open()\spragma\scalls,\sas\sthose\s(A)\salready\sreflected\sthe\sbuild-time\sdefault\ssettings\sand\s(B)\sthey\smade\sit\sillegal\sto\srun\slocking_mode=exclusive,\swhich\sis\sa\srequirement\sfor\sWAL\smode\swithout\sshared\smemory.\sModify\spart\sof\sthe\stest\ssuite\sto\sdemonstrate\sthat\sthe\sSAHPool\sVFS\scan\srun\sin\sWAL\smode\sso\slong\sas\slocking_mode=exclusive\sis\sused.
-D 2024-07-22T19:52:02.340
+D 2024-07-22T20:58:51.797
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -612,14 +612,14 @@ F ext/wasm/api/post-js-header.js 04dc12c3edd666b64a1b4ef3b6690c88dcc653f26451fd4
 F ext/wasm/api/pre-js.c-pp.js ad906703f7429590f2fbf5e6498513bf727a1a4f0ebfa057afb08161d7511219
 F ext/wasm/api/sqlite3-api-cleanup.js d235ad237df6954145404305040991c72ef8b1881715d2a650dda7b3c2576d0e
 F ext/wasm/api/sqlite3-api-glue.c-pp.js 21a0f8c1e4b4675b6563759c74bef954ac36aa99acce79c56802b661429f43d0
-F ext/wasm/api/sqlite3-api-oo1.c-pp.js aba93e986b141454af2be42f37dfcfaaa981434a3801af3e48f621b620e43061
+F ext/wasm/api/sqlite3-api-oo1.c-pp.js 2e6ac2fc9cf77f7a77980a71930ce0b3e0469b0c87da7a161abd3bc365e4e3ec
 F ext/wasm/api/sqlite3-api-prologue.js b347a0c5350247f90174a0ad9b9e72a99a5f837f31f78f60fcdb829b2ca30b63
 F ext/wasm/api/sqlite3-api-worker1.c-pp.js 5cc22a3c0d52828cb32aad8691488719f47d27567e63e8bc8b832d74371c352d
 F ext/wasm/api/sqlite3-license-version-header.js 0c807a421f0187e778dc1078f10d2994b915123c1223fe752b60afdcd1263f89
 F ext/wasm/api/sqlite3-opfs-async-proxy.js e8f1df56e97a29004a95a2eddd26778f52c33b3e797d32d4b1b668a38e6493dd
 F ext/wasm/api/sqlite3-vfs-helper.c-pp.js 3f828cc66758acb40e9c5b4dcfd87fd478a14c8fb7f0630264e6c7fa0e57515d
-F ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js 8c59ff35224adbe926b85d0c6debedc63c3c949d4cee761b3a74867b56155341
+F ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js e529a99b7d5a088284821e2902b20d3404b561126969876997d5a73a656c9199
-F ext/wasm/api/sqlite3-vfs-opfs.c-pp.js 5868293eda205e74f2f5d1ada0077a6afca6981c7eba9f147736c31cde165e8b
+F ext/wasm/api/sqlite3-vfs-opfs.c-pp.js e99e3d99f736937914527070f00ab13e9391d3f1cef884ab99a64cbcbee8d675
 F ext/wasm/api/sqlite3-vtab-helper.c-pp.js a2fcbc3fecdd0eea229283584ebc122f29d98194083675dbe5cb2cf3a17fe309
 F ext/wasm/api/sqlite3-wasm.c 9267174b9b0591b4f71193542ab57adf95bb9415f7d3453acf4a8ca8052f5e6c
 F ext/wasm/api/sqlite3-worker1-promiser.c-pp.js 46f303ba8ddd1b2f0a391798837beddfa72e8c897038c8047eda49ce7d5ed46b
@@ -667,7 +667,7 @@ F ext/wasm/test-opfs-vfs.html 1f2d672f3f3fce810dfd48a8d56914aba22e45c6834e262555
 F ext/wasm/test-opfs-vfs.js 1618670e466f424aa289859fe0ec8ded223e42e9e69b5c851f809baaaca1a00c
 F ext/wasm/tester1-worker.html ebc4b820a128963afce328ecf63ab200bd923309eb939f4110510ab449e9814c
 F ext/wasm/tester1.c-pp.html 1c1bc78b858af2019e663b1a31e76657b73dc24bede28ca92fbe917c3a972af2
-F ext/wasm/tester1.c-pp.js 619964ecb359f5385ed0724f43e0eaee218daceaebc27997a230687dd7333499
+F ext/wasm/tester1.c-pp.js 4f68682b64d5cd3e956803c0ee90457a3c47af4eecda4775e7fa4e66fde4a183
 F ext/wasm/tests/opfs/concurrency/index.html 657578a6e9ce1e9b8be951549ed93a6a471f4520a99e5b545928668f4285fb5e
 F ext/wasm/tests/opfs/concurrency/test.js d08889a5bb6e61937d0b8cbb78c9efbefbf65ad09f510589c779b7cc6a803a88
 F ext/wasm/tests/opfs/concurrency/worker.js 0a8c1a3e6ebb38aabbee24f122693f1fb29d599948915c76906681bb7da1d3d2
@@ -2195,8 +2195,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P b6aed8bcb06edc7f0221fd707d5adc227856fe62dbcaae5ffe1fb4faa5c542e1
+P 9df3f1f24c6346dc94695bf533501c54379bb6e3cf492b67dda8a64a6a1eb495
-R 202e5ba85a746eaa1bad2f1008edf0f0
+R 1a7770728d958b8cba816bd7bdd2e0a2
 U stephan
-Z 9b5070ff548645dbd81801cffcf25f1a
+Z ad279efb20ab2e4ae7b776e5a3c20df2
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-9df3f1f24c6346dc94695bf533501c54379bb6e3cf492b67dda8a64a6a1eb495
+19cd8e2b056d7842ee39afb7160c901c9dc55a5bac8049cb0b5246210f6b920d