diff options
Diffstat (limited to 'ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js')
| -rw-r--r-- | ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js | 148 |
1 files changed, 125 insertions, 23 deletions
diff --git a/ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js b/ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js index 6551b5c89..e1e7b45b8 100644 --- a/ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js +++ b/ext/wasm/api/sqlite3-vfs-opfs-sahpool.c-pp.js @@ -501,22 +501,10 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ currently-opened client-specified filenames. */ getFileNames(){ const rc = []; - const iter = this.#mapFilenameToSAH.keys(); - for(const n of iter) rc.push(n); + for(const n of this.#mapFilenameToSAH.keys()) rc.push(n); return rc; } -// #createFileObject(sah,clientName,opaqueName){ -// const f = Object.assign(Object.create(null),{ -// clientName, opaqueName -// }); -// this.#mapSAHToMeta.set(sah, f); -// return f; -// } -// #unmapFileObject(sah){ -// this.#mapSAHToMeta.delete(sah); -// } - /** Adds n files to the pool's capacity. This change is persistent across settings. Returns a Promise which resolves @@ -557,8 +545,9 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ } /** - Releases all currently-opened SAHs. The only legal - operation after this is acquireAccessHandles(). + Releases all currently-opened SAHs. The only legal operation + after this is acquireAccessHandles() or (if this is called from + pauseVfs()) either of isPaused() or unpauseVfs(). */ releaseAccessHandles(){ for(const ah of this.#mapSAHToName.keys()) ah.close(); @@ -568,17 +557,21 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ } /** - Opens all files under this.vfsDir/this.#dhOpaque and acquires - a SAH for each. returns a Promise which resolves to no value - but completes once all SAHs are acquired. If acquiring an SAH - throws, SAHPool.$error will contain the corresponding - exception. + Opens all files under this.vfsDir/this.#dhOpaque and acquires a + SAH for each. Returns a Promise which resolves to no value but + completes once all SAHs are acquired. If acquiring an SAH + throws, this.$error will contain the corresponding Error + object. + + If it throws, it releases any SAHs which it may have + acquired before the exception was thrown, leaving the VFS in a + well-defined but unusable state. If clearFiles is true, the client-stored state of each file is cleared when its handle is acquired, including its name, flags, and any data stored after the metadata block. */ - async acquireAccessHandles(clearFiles){ + async acquireAccessHandles(clearFiles=false){ const files = []; for await (const [name,h] of this.#dhOpaque){ if('file'===h.kind){ @@ -832,12 +825,18 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ Removes this object's sqlite3_vfs registration and shuts down this object, releasing all handles, mappings, and whatnot, including deleting its data directory. There is currently no - way to "revive" the object and reaquire its resources. + way to "revive" the object and reaquire its + resources. Similarly, there is no recovery strategy if removal + of any given SAH fails, so such errors are ignored by this + function. This function is intended primarily for testing. Resolves to true if it did its job, false if the VFS has already been shut down. + + @see pauseVfs() + @see unpauseVfs() */ async removeVfs(){ if(!this.#cVfs.pointer || !this.#dhOpaque) return false; @@ -853,13 +852,77 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ ); this.#dhVfsRoot = this.#dhVfsParent = undefined; }catch(e){ - sqlite3.config.error(this.vfsName,"removeVfs() failed:",e); + sqlite3.config.error(this.vfsName,"removeVfs() failed with no recovery strategy:",e); /*otherwise ignored - there is no recovery strategy*/ } return true; } + /** + "Pauses" this VFS by unregistering it from SQLite and + relinquishing all open SAHs, leaving the associated files + intact. If this object is already paused, this is a + no-op. Returns this object. + + This function throws if SQLite has any opened file handles + hosted by this VFS, as the alternative would be to invoke + Undefined Behavior by closing file handles out from under the + library. Similarly, automatically closing any database handles + opened by this VFS would invoke Undefined Behavior in + downstream code which is holding those pointers. + + If this function throws due to open file handles then it has + no side effects. If the OPFS API throws while closing handles + then the VFS is left in an undefined state. + + @see isPaused() + @see unpauseVfs() + */ + pauseVfs(){ + if(this.#mapS3FileToOFile_.size>0){ + sqlite3.SQLite3Error.toss( + capi.SQLITE_MISUSE, "Cannot pause VFS", + this.vfsName,"because it has opened files." + ); + } + if(this.#mapSAHToName.size>0){ + capi.sqlite3_vfs_unregister(this.vfsName); + this.releaseAccessHandles(); + } + return this; + } + + /** + Returns true if this pool is currently paused else false. + + @see pauseVfs() + @see unpauseVfs() + */ + isPaused(){ + return 0===this.#mapSAHToName.size; + } + + /** + "Unpauses" this VFS, reacquiring all SAH's and (if successful) + re-registering it with SQLite. This is a no-op if the VFS is + not currently paused. + + The returned Promise resolves to this object. See + acquireAccessHandles() for how it behaves if it throws due to + SAH acquisition failure. + + @see isPaused() + @see pauseVfs() + */ + async unpauseVfs(){ + if(0===this.#mapSAHToName.size){ + return this.acquireAccessHandles(false). + then(()=>capi.sqlite3_vfs_register(this.#cVfs, 0),this); + } + return this; + } + //! Documented elsewhere in this file. exportFile(name){ const sah = this.#mapFilenameToSAH.get(name) || toss("File not found:",name); @@ -984,6 +1047,10 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ async removeVfs(){ return this.#p.removeVfs() } + pauseVfs(){ this.#p.pauseVfs(); return this; } + async unpauseVfs(){ return this.#p.unpauseVfs().then(()=>this); } + isPaused(){ return this.#p.isPaused() } + }/* class OpfsSAHPoolUtil */; /** @@ -1217,6 +1284,41 @@ globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ Clears all client-defined state of all SAHs and makes all of them available for re-use by the pool. Results are undefined if any such handles are currently in use, e.g. by an sqlite3 db. + + APIs specific to the "pause" capability (added in version 3.49): + + Summary: "pausing" the VFS disassociates it from SQLite and + relinquishes its SAHs so that they may be opened by another + instance of this VFS (running in a separate tab/page or Worker). + "Unpausing" it takes back control, if able. + + - pauseVfs() + + "Pauses" this VFS by unregistering it from SQLite and + relinquishing all open SAHs, leaving the associated files intact. + This enables pages/tabs to coordinate semi-concurrent usage of + this VFS. If this object is already paused, this is a + no-op. Returns this object. Throws if SQLite has any opened file + handles hosted by this VFS. If this function throws due to open + file handles then it has no side effects. If the OPFS API throws + while closing handles then the VFS is left in an undefined state. + + - isPaused() + + Returns true if this VFS is paused, else false. + + - [async] unpauseVfs() + + Restores the VFS to an active state after having called + pauseVfs() on it. This is a no-op if the VFS is not paused. The + returned Promise resolves to this object on success. A rejected + Promise means there was a problem reacquiring the SAH handles + (possibly because they're in use by another instance or have + since been removed). Generically speaking, there is no recovery + strategy for that type of error, but if the problem is simply + that the OPFS files are locked, then a later attempt to unpause + it, made after the concurrent instance releases the SAHs, may + recover from the situation. */ sqlite3.installOpfsSAHPoolVfs = async function(options=Object.create(null)){ options = Object.assign(Object.create(null), optionDefaults, (options||{})); |