Add delete-before-open=1 URI flag to the 'opfs' VFS to tell it to xDelete the db file before opening it, primarily to enable users to work around a corrupt db without having to reach into OPFS-specific APIs to remove the db file.

FossilOrigin-Name: e83f9788636f7f9bcca7d2a09620c13ab4eb83436d5b2946a827e48addf0267d

2 files changed, 26 insertions, 3 deletions

diff --git a/ext/wasm/api/sqlite3-opfs-async-proxy.js b/ext/wasm/api/sqlite3-opfs-async-proxy.js
index cafd296c6..58b8bcb23 100644
--- a/ext/wasm/api/sqlite3-opfs-async-proxy.js
+++ b/ext/wasm/api/sqlite3-opfs-async-proxy.js
@@ -562,6 +562,17 @@ const installAsyncProxy = function(self){
           wTimeEnd();
           return;
         }
+        if( state.opfsFlags.OPFS_UNLINK_BEFORE_OPEN & opfsFlags ){
+          //log("async proxy opfsFlags =",opfsFlags);
+          try{
+            await hDir.removeEntry(filenamePart);
+            //log("Unlinked",filename,hDir,filenamePart);
+          }
+          catch(e){
+            /* ignoring */
+            //warn("Ignoring failed Unlink of",filename,":",e);
+          }
+        }
         const hFile = await hDir.getFileHandle(filenamePart, {create});
         wTimeEnd();
         const fh = Object.assign(Object.create(null),{
diff --git a/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js b/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js
index f7fd951a4..65e39e5b5 100644
--- a/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js
+++ b/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js
@@ -423,11 +423,19 @@ const installOpfsVfs = function callee(options){
     });
     state.opfsFlags = Object.assign(Object.create(null),{
       /**
-         Flag for use with xOpen(). "opfs-unlock-asap=1" enables
-         this. See defaultUnlockAsap, below.
+         Flag for use with xOpen(). URI flag "opfs-unlock-asap=1"
+         enables this. See defaultUnlockAsap, below.
        */
       OPFS_UNLOCK_ASAP: 0x01,
       /**
+         Flag for use with xOpen(). URI flag "delete-before-open=1"
+         tells the VFS to delete the db file before attempting to open
+         it. This can be used, e.g., to replace a db which has been
+         corrupted (without forcing us to expose a delete/unlink()
+         function in the public API).
+      */
+      OPFS_UNLINK_BEFORE_OPEN: 0x02,
+      /**
          If true, any async routine which implicitly acquires a sync
          access handle (i.e. an OPFS lock) will release that locks at
          the end of the call which acquires it. If false, such
@@ -875,13 +883,17 @@ const installOpfsVfs = function callee(options){
         let opfsFlags = 0;
         if(0===zName){
           zName = randomFilename();
-        }else if('number'===typeof zName){
+        }else if(wasm.isPtr(zName)){
           if(capi.sqlite3_uri_boolean(zName, "opfs-unlock-asap", 0)){
             /* -----------------------^^^^^ MUST pass the untranslated
                C-string here. */
             opfsFlags |= state.opfsFlags.OPFS_UNLOCK_ASAP;
           }
+          if(capi.sqlite3_uri_boolean(zName, "delete-before-open", 0)){
+            opfsFlags |= state.opfsFlags.OPFS_UNLINK_BEFORE_OPEN;
+          }
           zName = wasm.cstrToJs(zName);
+          //warn("xOpen zName =",zName, "opfsFlags =",opfsFlags);
         }
         const fh = Object.create(null);
         fh.fid = pFile;