From: stephan <stephan@noemail.net>
Date: Fri, 21 Nov 2025 22:13:35 +0000 (+0000)
Subject: Get initial JS overrides of the kvvfs sqlite3_vfs and sqlite3_io_methods in place... 
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=92fa31bc5fb72159e892aa6910690a92a6452671;p=thirdparty%2Fsqlite.git

Get initial JS overrides of the kvvfs sqlite3_vfs and sqlite3_io_methods in place. It now tracks a distinct Storage-ish object per sqlite3_file instance.

FossilOrigin-Name: 19a3349a2031e2b7fae67847b55643e4f70f8dae863ebc1ace3b09d1f482c8eb
---

diff --git a/ext/wasm/api/sqlite3-vfs-kvvfs.c-pp.js b/ext/wasm/api/sqlite3-vfs-kvvfs.c-pp.js
index 03d170e6ab..2d69be891b 100644
--- a/ext/wasm/api/sqlite3-vfs-kvvfs.c-pp.js
+++ b/ext/wasm/api/sqlite3-vfs-kvvfs.c-pp.js
@@ -31,8 +31,7 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
 
   if( !pKvvfs ) return /* nothing to do */;
 
-  const util = sqlite3.util,
-        wasm = sqlite3.wasm;
+  const util = sqlite3.util;
 
   if( !util.isUIThread() ){
     /* One test currently relies on this VFS not being visible in
@@ -43,18 +42,18 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
     return;
   }
 
-  const __hop = (o,k)=>Object.prototype.hasOwnProperty.call(o,k);
+  const wasm = sqlite3.wasm,
+        hop = (o,k)=>Object.prototype.hasOwnProperty.call(o,k);
   /**
      Implementation of JS's Storage interface for use
      as backing store of the kvvfs.
   */
-  class ObjectStorage extends Storage {
+  class ObjectStorage /* extends Storage (ctor may not be legally called) */ {
     #map;
     #keys;
     #getKeys(){return this.#keys ??= Object.keys(this.#map);}
 
     constructor(){
-      super();
       this.clear();
     }
 
@@ -68,7 +67,7 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
     }
 
     setItem(k,v){
-      if( !__hop(this.#map, k) ){
+      if( !hop(this.#map, k) ){
         this.#keys = null;
       }
       this.#map[k]=v;
@@ -90,19 +89,6 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
     }
   }/*ObjectStorage*/;
 
-  const kvvfsState = Object.assign(Object.create(null),{
-    jClassToStorage: new Map(
-      /* Map of JS-format KVVfsFile::zClass values to Storage
-         object. We can't use WeakMap because that requires an Object
-         or Symbol as a key, and we can't use Symbol in this
-         context. We don't use KVVfsFile::zClass pointers as keys only
-         because of some special-casing for local/session journal
-         files which remaps those pointers. */
-    )
-  });
-  kvvfsState.jClassToStorage.set('local', localStorage);
-  kvvfsState.jClassToStorage.set('session', sessionStorage);
-
   /**
      Internal helper for sqlite3_js_kvvfs_clear() and friends.
      Its argument should be one of ('local','session',"").
@@ -111,20 +97,13 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
     const rc = Object.create(null);
     rc.prefix = 'kvvfs-'+which;
     rc.stores = [];
-    let got = 0;
     if( globalThis.sessionStorage
         && ('session'===which || ""===which)){
       rc.stores.push(globalThis.sessionStorage);
-      ++got;
     }
     if( globalThis.localStorage
         && ('local'===which || ""===which) ){
       rc.stores.push(globalThis.localStorage);
-      ++got;
-    }
-    if( !got && which ){
-      const x = kvvfsState.jClassToStorage.get(which);
-      if( x ) rc.stores.push(x);
     }
     return rc;
   };
@@ -193,34 +172,74 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
 
   const kvvfsMakeKey = wasm.exports.sqlite3__wasm_kvvfsMakeKeyOnPstack;
   const pstack = wasm.pstack;
+  const cache = Object.create(null);
+  cache.jzClassToStorage = Object.assign(Object.create(null),{
+    /* Map of JS-stringified KVVfsFile::zClass names to
+       reference-counted Storage objects. We refcount so that xClose()
+       does not pull one out from another instance. */
+    local:             {refc: 2, s: globalThis.localStorage},
+    session:           {refc: 2, s: globalThis.sessionStorage}
+  });
+  cache.jzClassToStorage['local-journal'] =
+    cache.jzClassToStorage.local;
+  cache.jzClassToStorage['session-journal'] =
+    cache.jzClassToStorage.session;
+
+
   const kvvfsStorage = function(zClass){
     const s = wasm.cstrToJs(zClass);
-    if( !this.rxSession ){
-      this.rxSession = /^session(-journal)?$/;
-      this.rxLocal = /^local(-journal)?$/;
+    if( cache.jzClassToStorage[s] ){
+      return cache.jzClassToStorage[s].s;
+    }
+    if( !cache.rxSession ){
+      cache.rxSession = /^session(-journal)?$/;
+      cache.rxLocal = /^local(-journal)?$/;
     }
-    if( this.rxSession.test(s) ) return sessionStorage;
-    if( this.rxLocal.test(s) ) return localStorage;
-    return kvvfsStorage.jClassToStorage.get(s);
+    if( cache.rxSession.test(s) ) return sessionStorage;
+    if( cache.rxLocal.test(s) ) return localStorage;
+    return cache.jzClassToStorage(s)?.s;
   }.bind(Object.create(null));
 
-  { /* Override native sqlite3_kvvfs_methods */
-    const kvvfsMethods = new sqlite3_kvvfs_methods(
-      /* Wraps the static sqlite3_api_methods singleton */
-      wasm.exports.sqlite3__wasm_kvvfs_methods()
-    );
-    try{
-      /**
-         Implementations for members of the object referred to by
-         sqlite3__wasm_kvvfs_methods(). We swap out the native
-         implementations with these, which use JS Storage for their
-         backing store.
-
-         The interface docs for these methods are in
-         src/os_kv.c:kvrecordRead(), kvrecordWrite(), and
-         kvrecordDelete().
-      */
-      for(const e of Object.entries({
+  const pFileHandles = new Map(
+    /* sqlite3_file pointers => objects, each of which has:
+       .s = Storage object
+       .f = KVVfsFile instance
+       .n = JS-string form of f.$zName
+    */
+  );
+
+  const debug = sqlite3.config.debug.bind(sqlite3.config);
+  const warn = sqlite3.config.warn.bind(sqlite3.config);
+
+  {
+    /**
+       Original WASM functions for methods we partially override.
+    */
+    const originalMethods = {
+      vfs: Object.create(null),
+      ioDb: Object.create(null),
+      ioJrnl: Object.create(null)
+    };
+
+    /** Returns the appropriate originalMethods[X] instance for the
+        given a KVVfsFile instance. */
+    const originalIoMethods = (kvvfsFile)=>
+          originalMethods[kvvfsFile.$isJournal ? 'ioJrnl' : 'ioDb'];
+
+    /**
+       Implementations for members of the object referred to by
+       sqlite3__wasm_kvvfs_methods(). We swap out the native
+       implementations with these, which use JS Storage for their
+       backing store.
+
+       The interface docs for these methods are in
+       src/os_kv.c:kvrecordRead(), kvrecordWrite(), and
+       kvrecordDelete().
+    */
+    sqlite3_kvvfs_methods.override = {
+
+      /* sqlite3_kvvfs_methods's own direct methods */
+      recordHandler: {
         xRcrdRead: (zClass, zKey, zBuf, nBuf)=>{
           const stack = pstack.pointer,
                 astack = wasm.scopedAllocPush();
@@ -253,6 +272,7 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
             wasm.scopedAllocPop(astack);
           }
         },
+
         xRcrdWrite: (zClass, zKey, zData)=>{
           const stack = pstack.pointer;
           try {
@@ -268,6 +288,7 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
             pstack.restore(stack);
           }
         },
+
         xRcrdDelete: (zClass, zKey)=>{
           const stack = pstack.pointer;
           try {
@@ -282,62 +303,96 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
             pstack.restore(stack);
           }
         }
-      })){
-        kvvfsMethods[kvvfsMethods.memberKey(e[0])] =
-          wasm.installFunction(kvvfsMethods.memberSignature(e[0]), e[1]);
-      }
-    }finally{
-      kvvfsMethods.dispose();
-    }
-  }/* Override native sqlite3_api_methods */
-
-  /**
-     After initial refactoring to support the use of arbitrary Storage
-     objects (the interface from which localStorage and sessionStorage
-     dervie), we will apparently need to override some of the
-     associated sqlite3_vfs and sqlite3_io_methods members.
-
-     We can call back into the native impls when needed, but we need
-     to override certain operations here to bypass its strict
-     db-naming rules (which, funnily enough, are in place because
-     they're relevant (only) for what should soon be the previous
-     version of this browser-side implementation). Apropos: the port
-     to generic objects would also make non-persistent kvvfs available
-     in Worker threads and non-browser builds. They could optionally
-     be exported to/from JSON.
-  */
-  const eventualTodo = {
-    vfsMethods:{
-//#if nope
+      }/*recordHandler*/,
       /**
+         After initial refactoring to support the use of arbitrary Storage
+         objects (the interface from which localStorage and sessionStorage
+         dervie), we will apparently need to override some of the
+         associated sqlite3_vfs and sqlite3_io_methods members.
+
+         We can call back into the native impls when needed, but we
+         need to override certain operations here to bypass its strict
+         db-naming rules (which, funnily enough, are in place because
+         they're relevant (only) for what should soon be the previous
+         version of this browser-side implementation). Apropos: the
+         port to generic objects would also make non-persistent kvvfs
+         available in Worker threads and non-browser builds. They
+         could optionally be exported to/from JSON.
       */
-      xOpen: function(pProtoVfs,zName,pProtoFile,flags,pOutFlags){
-      },
-      xDelete: function(pVfs, zName, iSyncFlag){},
-      xAccess:function(pProtoVfs, zPath, flags, pResOut){},
-      xFullPathname: function(pVfs, zPath, nOut, zOut){},
-      xDlOpen: function(pVfs, zFilename){},
-      xSleep: function(pVfs,usec){},
-      xCurrentTime: function(pVfs,pOutDbl){},
-      xCurrentTimeInt64: function(pVfs,pOutI64){},
-      xRandomness: function(pVfs, nOut, pOut){
-        const heap = wasm.heap8u();
-        let i = 0;
-        const npOut = Number(pOut);
-        for(; i < nOut; ++i) heap[npOut + i] = (Math.random()*255000) & 0xFF;
-        return i;
-      }
+      /* sqlite3_kvvfs_methods::pVfs's methods */
+      vfs:{
+        /**
+         */
+        xOpen: function(pProtoVfs,zName,pProtoFile,flags,pOutFlags){
+          try{
+            const rc = originalMethods.vfs.xOpen(pProtoVfs, zName, pProtoFile,
+                                                 flags, pOutFlags);
+            if( 0==rc ){
+              const jzName = wasm.cstrToJs(zName);
+              const f = new KVVfsFile(pProtoFile);
+              let s = cache.jzClassToStorage[jzName];
+              if( s ){
+                ++s.refc;
+              }else{
+                s = cache.jzClassToStorage[jzName] = {
+                  refc: 1,
+                  s: new ObjectStorage
+                };
+              }
+              debug("kvvfs xOpen", f, jzName, s);
+              pFileHandles.set(pProtoFile, {s,f,n:jzName});
+            }
+            return rc;
+          }catch(e){
+            warn("kvvfs xOpen:",e);
+            return capi.SQLITE_ERROR;
+          }
+        },
+//#if nope
+        xDelete: function(pVfs, zName, iSyncFlag){},
+        xAccess:function(pProtoVfs, zPath, flags, pResOut){},
+        xFullPathname: function(pVfs, zPath, nOut, zOut){},
+        xDlOpen: function(pVfs, zFilename){},
+        xSleep: function(pVfs,usec){},
+        xCurrentTime: function(pVfs,pOutDbl){},
+        xCurrentTimeInt64: function(pVfs,pOutI64){},
 //#endif
-    },
-
+        xRandomness: function(pVfs, nOut, pOut){
+          const heap = wasm.heap8u();
+          let i = 0;
+          const npOut = Number(pOut);
+          for(; i < nOut; ++i) heap[npOut + i] = (Math.random()*255000) & 0xFF;
+          return i;
+        }
+      },
+      /**
+         kvvfs has separate sqlite3_api_methods impls for some of the
+         methods, depending on whether it's a db or journal file. Some
+         of the methods use shared impls but others are specific to
+         either db or journal files.
+      */
+      ioDb:{
+        /* sqlite3_kvvfs_methods::pIoDb's methods */
+        xClose: function(pFile){
+          try{
+            const h = pFileHandles.get(pFile);
+            debug("kvvfs xClose", pFile, h);
+            pFileHandles.delete(pFile);
+            const s = cache.jzClassToStorage[h.n];
+            if( 0===--s.refc ){
+              delete cache.jzClassToStorage[h.n];
+              delete s.s;
+              delete s.refc;
+            }
+            originalIoMethods(h.f).xClose(pFile);
+            h.f.dispose();
+            return 0;
+          }catch(e){
+            warn("kvvfs xClose",e);
+            return capi.SQLITE_ERROR;
+          }
+        },
 //#if nope
-    /**
-       kvvfs has separate impls for some of the I/O methods,
-       depending on whether it's a db or journal file.
-    */
-    ioMethods:{
-      db:{
-        xClose: function(pFile){},
         xRead: function(pFile,pTgt,n,iOff64){},
         xWrite: function(pFile,pSrc,n,iOff64){},
         xTruncate: function(pFile,i64){},
@@ -350,25 +405,88 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
         xFileControl: function(pFile,iOp,pArg){},
         xSectorSize: function(pFile){},
         xDeviceCharacteristics: function(pFile){}
+//#endif
       },
-      jrnl:{
-        xClose: todoIOMethodsDb.xClose,
+      ioJrnl:{
+        /* sqlite3_kvvfs_methods::pIoJrnl's methods. Those set to true
+           are copied as-is from the ioDb objects. Others are specific
+           to journal files. */
+        xClose: true,
+//#if nope
         xRead: function(pFile,pTgt,n,iOff64){},
         xWrite: function(pFile,pSrc,n,iOff64){},
         xTruncate: function(pFile,i64){},
         xSync: function(pFile,flags){},
         xFileControl: function(pFile, opId, pArg){},
         xFileSize: function(pFile,pi64Out){},
-        xLock: todoIOMethodsDb.xLock,
-        xUnlock: todoIOMethodsDb.xUnlock,
-        xCheckReservedLock: todoIOMethodsDb.xCheckReservedLock,
+        xLock: true,
+        xUnlock: true,
+        xCheckReservedLock: true,
         xFileControl: function(pFile,iOp,pArg){},
-        xSectorSize: todoIOMethodsDb.xSectorSize,
-        xDeviceCharacteristics: todoIOMethodsDb.xDeviceCharacteristics
+        xSectorSize: true,
+        xDeviceCharacteristics: true
+//#endif
       }
+    }/*sqlite3_kvvfs_methods.override*/;
+
+    const ov = sqlite3_kvvfs_methods.override;
+    const kvvfsMethods = new sqlite3_kvvfs_methods(
+      /* Wraps the static sqlite3_api_methods singleton */
+      wasm.exports.sqlite3__wasm_kvvfs_methods()
+    );
+    const pVfs = new capi.sqlite3_vfs(kvvfsMethods.$pVfs);
+    const pIoDb = new capi.sqlite3_io_methods(kvvfsMethods.$pIoDb);
+    const pIoJrnl = new capi.sqlite3_io_methods(kvvfsMethods.$pIoJrnl);
+    debug("pVfs and friends",pVfs, pIoDb, pIoJrnl);
+    try {
+      for(const e of Object.entries(ov.recordHandler)){
+        // Overwrite kvvfsMethods's callbacks
+        kvvfsMethods[kvvfsMethods.memberKey(e[0])] =
+          wasm.installFunction(kvvfsMethods.memberSignature(e[0]), e[1]);
+      }
+      for(const e of Object.entries(ov.vfs)){
+        // Overwrite some pVfs entries and stash the original impls
+        const k = e[0],
+              f = e[1],
+              km = pVfs.memberKey(k),
+              mbr = pVfs.structInfo.members[k] || util.toss("Missing pVfs member ",km);
+        originalMethods.vfs[k] = wasm.functionEntry(pVfs[km]);
+        pVfs[km] = wasm.installFunction(mbr.signature, f);
+      }
+      for(const e of Object.entries(ov.ioDb)){
+        // Similar treatment for pVfs.$pIoDb a.k.a. pIoDb...
+        const k = e[0],
+              f = e[1],
+              km = pIoDb.memberKey(k),
+              mbr = pIoDb.structInfo.members[k];
+        if( !mbr ){
+          warn("Missinog pIoDb member",k,km,pIoDb.structInfo);
+          util.toss("Missing pIoDb member",k,km);
+        }
+        originalMethods.ioDb[k] = wasm.functionEntry(pIoDb[km]);
+        pIoDb[km] = wasm.installFunction(mbr.signature, f);
+      }
+      for(const e of Object.entries(ov.ioJrnl)){
+        // Similar treatment for pVfs.$pIoJrnl a.k.a. pIoJrnl...
+        const k = e[0],
+              f = e[1],
+              km = pIoJrnl.memberKey(k);
+        originalMethods.ioJrnl[k] = wasm.functionEntry(pIoJrnl[km]);
+        if( true===f ){
+          /* use pIoDb's copy */
+          pIoJrnl[km] = pIoDb[km] || util.toss("Missing copied pIoDb member",km);
+        }else{
+          const mbr = pIoJrnl.structInfo.members[k] || util.toss("Missing pIoJrnl member",km)
+          pIoJrnl[km] = wasm.installFunction(mbr.signature, f);
+        }
+      }
+    }finally{
+      kvvfsMethods.dispose();
+      pVfs.dispose();
+      pIoDb.dispose();
+      pIoJrnl.dispose();
     }
-//#endif
-  }/*eventualTodo*/;
+  }/*method overrides*/
 
   if(sqlite3?.oo1?.DB){
     /**
@@ -393,7 +511,7 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
       const opt = sqlite3.oo1.DB.dbCtorHelper.normalizeArgs(...arguments);
       storageName = opt.filename;
       if('session'!==storageName && 'local'!==storageName){
-        toss3("JsStorageDb db name must be one of 'session' or 'local'.");
+        util.toss3("JsStorageDb db name must be one of 'session' or 'local'.");
       }
       opt.vfs = 'kvvfs';
       sqlite3.oo1.DB.dbCtorHelper.call(this, opt);
diff --git a/ext/wasm/api/sqlite3-wasm.c b/ext/wasm/api/sqlite3-wasm.c
index a83bd52f7b..e6dc7590e0 100644
--- a/ext/wasm/api/sqlite3-wasm.c
+++ b/ext/wasm/api/sqlite3-wasm.c
@@ -1105,6 +1105,7 @@ const char * sqlite3__wasm_enum_json(void){
     StructBinder {
       M(base,               "p")/*sqlite3_file base*/;
       M(zClass,             "s");
+      M(zName,              "s");
       M(isJournal,          "i");
       M(nJrnl,              "i")/*actually unsigned!*/;
       M(aJrnl,              "p");
diff --git a/manifest b/manifest
index 9e8a6bcc6a..13a51935e8 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C More\swork\stowards\susing\sJS\sgeneric\sStorage\sobjects\sas\sdb\spage\sstorage\svia\skvvfs.
-D 2025-11-21T18:55:33.689
+C Get\sinitial\sJS\soverrides\sof\sthe\skvvfs\ssqlite3_vfs\sand\ssqlite3_io_methods\sin\splace.\sIt\snow\stracks\sa\sdistinct\sStorage-ish\sobject\sper\ssqlite3_file\sinstance.
+D 2025-11-21T22:13:35.200
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -600,11 +600,11 @@ F ext/wasm/api/sqlite3-api-worker1.c-pp.js 1041dd645e8e821c082b628cd8d9acf70c667
 F ext/wasm/api/sqlite3-license-version-header.js 0c807a421f0187e778dc1078f10d2994b915123c1223fe752b60afdcd1263f89
 F ext/wasm/api/sqlite3-opfs-async-proxy.js 9654b565b346dc609b75d15337f20acfa7af7d9d558da1afeb9b6d8eaa404966
 F ext/wasm/api/sqlite3-vfs-helper.c-pp.js 3f828cc66758acb40e9c5b4dcfd87fd478a14c8fb7f0630264e6c7fa0e57515d
-F ext/wasm/api/sqlite3-vfs-kvvfs.c-pp.js e84a6ec93acb2f6f2a19378ec7d3317de65d37dc75b13b70ad2b51b512268468
+F ext/wasm/api/sqlite3-vfs-kvvfs.c-pp.js b8e37020d69e09348e16111a989f29ffa41fc719412d0ea7ffd1e8f51db91417
 F ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js 26cb41d5a62f46a106b6371eb00fef02de3cdbfaa51338ba087a45f53028e0d0
 F ext/wasm/api/sqlite3-vfs-opfs.c-pp.js aa330fa0e8ef35cbd92eb0d52e05fbaa07e61540c5cb164e693c82428ce1d763
 F ext/wasm/api/sqlite3-vtab-helper.c-pp.js 9097074724172e31e56ce20ccd7482259cf72a76124213cbc9469d757676da86
-F ext/wasm/api/sqlite3-wasm.c dea6f331a03a49b8613d1fd5afcb606e1d06e8ab1df8dd65ee967fbfdd43ca1a
+F ext/wasm/api/sqlite3-wasm.c e10ae835b1d8cb3bbc0974200a8339a96e66caed96d45ca962a5cebfd1a04e36
 F ext/wasm/api/sqlite3-worker1-promiser.c-pp.js bda1c75bd674a92a0e27cc2f3d46dbbf21e422413f8046814515a0bd7409328a
 F ext/wasm/api/sqlite3-worker1.c-pp.js 802d69ead8c38dc1be52c83afbfc77e757da8a91a2e159e7ed3ecda8b8dba2e7
 F ext/wasm/c-pp-lite.c 943be1a36774d58385dca32de36fc18d4f432fe79f7aa35e6c85dd6a6b825bd0
@@ -717,7 +717,7 @@ F src/notify.c 57c2d1a2805d6dee32acd5d250d928ab94e02d76369ae057dee7d445fd64e878
 F src/os.c 509452169d5ea739723e213b8e2481cf0e587f0e88579a912d200db5269f5f6d
 F src/os.h 1ff5ae51d339d0e30d8a9d814f4b8f8e448169304d83a7ed9db66a65732f3e63
 F src/os_common.h 6c0eb8dd40ef3e12fe585a13e709710267a258e2c8dd1c40b1948a1d14582e06
-F src/os_kv.c 26191ac1cb171ec3fceade6018ef66309cefba65e41f5ffe4c5385f2cb682ba7
+F src/os_kv.c b5de11f31634c36ac5ab04b14f6da67801f331b73384f852de0d77c98009818d
 F src/os_setup.h 8efc64eda6a6c2f221387eefc2e7e45fd5a3d5c8337a7a83519ba4fbd2957ae2
 F src/os_unix.c 7945ede1e85b2d1b910e1b4af9ba342e964b1e30e79f4176480a60736445cb36
 F src/os_win.c a89b501fc195085c7d6c9eec7f5bd782625e94bb2a96b000f4d009703df1083f
@@ -2178,8 +2178,8 @@ F tool/version-info.c 33d0390ef484b3b1cb685d59362be891ea162123cea181cb8e6d2cf6dd
 F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
 F tool/warnings.sh d924598cf2f55a4ecbc2aeb055c10bd5f48114793e7ba25f9585435da29e7e98
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 206275292217be4ff317d4c9186ecaf863ca69295e2f995ed175aa65d9ad11dc
-R 113fe1254ac4b59119cf9c28e45f222e
+P 90a33941c69b3581feaed271542f0238ca81ee34fe5b353ca7da48b81ac73a5f
+R 831d8b062b833be06147d18462b6029d
 U stephan
-Z bcdce04b0f6728fd8539031f7a059a7e
+Z 6ff913830f5e095f3c74b6184f98d188
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 585f31466a..0d050e20e1 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-90a33941c69b3581feaed271542f0238ca81ee34fe5b353ca7da48b81ac73a5f
+19a3349a2031e2b7fae67847b55643e4f70f8dae863ebc1ace3b09d1f482c8eb
diff --git a/src/os_kv.c b/src/os_kv.c
index f4c1fc84b6..4960feedc0 100644
--- a/src/os_kv.c
+++ b/src/os_kv.c
@@ -51,6 +51,7 @@ typedef struct KVVfsFile KVVfsFile;
 struct KVVfsFile {
   sqlite3_file base;              /* IO methods */
   const char *zClass;             /* Storage class */
+  const char *zName;              /* File name (used by the JS side) */
   int isJournal;                  /* True if this is a journal file */
   unsigned int nJrnl;             /* Space allocated for aJrnl[] */
   char *aJrnl;                    /* Journal content */
@@ -839,11 +840,11 @@ static int kvvfsOpen(
   SQLITE_KV_LOG(("xOpen(\"%s\")\n", zName));
   assert(!pFile->zClass);
   assert(!pFile->aData);
-  pFile->aData = 0;
-  pFile->aJrnl = 0;
-  pFile->nJrnl = 0;
+  assert(!pFile->aJrnl);
+  assert(!pFile->nJrnl);
   pFile->szPage = -1;
   pFile->szDb = -1;
+  pFile->zName = zName;
   if( 0==sqlite3_strglob("*-journal", zName) ){
     pFile->isJournal = 1;
     pFile->base.pMethods = &kvvfs_jrnl_io_methods;
@@ -863,6 +864,7 @@ static int kvvfsOpen(
 #ifndef SQLITE_WASM
     return SQLITE_CANTOPEN;
 #else
+    /* The JS impl maps these to Storage objects */
     pFile->zClass = zName;
 #endif
   }