Initial IndexedDB Support (#33044)

Adds indexeddb support to servo. At the moment heed is being used as the
backend, although this can be swapped out by implementing `KvsEngine`.
This PR adds a thread + a thread pool for Indexeddb related operations.
Also `database_access_task_source` is added for Indexeddb related
operations.

This is a partial rewrite of #25214. (Reopened due to branching issue)

Fixes #6963

---------

Signed-off-by: Ashwin Naren <arihant2math@gmail.com>
Signed-off-by: Josh Matthews <josh@joshmatthews.net>
Co-authored-by: Rasmus Viitanen <rasviitanen@gmail.com>
Co-authored-by: Josh Matthews <josh@joshmatthews.net>

components/shared/net/indexeddb_thread.rs

@@ -0,0 +1,173 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use ipc_channel::ipc::IpcSender;
+use serde::{Deserialize, Serialize};
+use servo_url::origin::ImmutableOrigin;
+
+#[derive(Debug, Deserialize, Serialize)]
+pub enum IndexedDBThreadReturnType {
+    Open(Option<u64>),
+    NextSerialNumber(u64),
+    StartTransaction(Result<(), ()>),
+    Commit(Result<(), ()>),
+    Version(u64),
+    CreateObjectStore(Option<String>),
+    UpgradeVersion(Result<u64, ()>),
+    KVResult(Option<Vec<u8>>),
+    Exit,
+}
+
+// https://www.w3.org/TR/IndexedDB-2/#enumdef-idbtransactionmode
+#[derive(Debug, Deserialize, Serialize)]
+pub enum IndexedDBTxnMode {
+    Readonly,
+    Readwrite,
+    Versionchange,
+}
+
+// https://www.w3.org/TR/IndexedDB-2/#key-type
+#[derive(Clone, Debug, Deserialize, Serialize)]
+pub enum IndexedDBKeyType {
+    Number(Vec<u8>),
+    String(Vec<u8>),
+    Binary(Vec<u8>),
+    Date(Vec<u8>),
+    // FIXME:(arihant2math) implment Array(),
+}
+
+// https://www.w3.org/TR/IndexedDB-2/#key-range
+#[derive(Clone, Debug, Deserialize, Serialize)]
+#[allow(unused)]
+pub enum IndexedDBKeyRange {}
+
+// Operations that are not executed instantly, but rather added to a
+// queue that is eventually run.
+#[derive(Debug, Deserialize, Serialize)]
+pub enum AsyncOperation {
+    /// Gets the value associated with the given key in the associated idb data
+    GetItem(
+        IndexedDBKeyType, // Key
+    ),
+
+    /// Sets the value of the given key in the associated idb data
+    PutItem(
+        IndexedDBKeyType, // Key
+        Vec<u8>,          // Value
+        bool,             // Should overwrite
+    ),
+
+    /// Removes the key/value pair for the given key in the associated idb data
+    RemoveItem(
+        IndexedDBKeyType, // Key
+    ),
+
+    Count(
+        IndexedDBKeyType, // Key
+    ),
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+pub enum SyncOperation {
+    // Upgrades the version of the database
+    UpgradeVersion(
+        IpcSender<IndexedDBThreadReturnType>,
+        ImmutableOrigin,
+        String, // Database
+        u64,    // Serial number for the transaction
+        u64,    // Version to upgrade to
+    ),
+    // Checks if an object store has a key generator, used in e.g. Put
+    HasKeyGenerator(
+        IpcSender<bool>,
+        ImmutableOrigin,
+        String, // Database
+        String, // Store
+    ),
+
+    // Commits changes of a transaction to the database
+    Commit(
+        IpcSender<IndexedDBThreadReturnType>,
+        ImmutableOrigin,
+        String, // Database
+        u64,    // Transaction serial number
+    ),
+
+    // Creates a new store for the database
+    CreateObjectStore(
+        IpcSender<Result<(), ()>>,
+        ImmutableOrigin,
+        String, // Database
+        String, // Store
+        bool,
+    ),
+
+    DeleteObjectStore(
+        IpcSender<Result<(), ()>>,
+        ImmutableOrigin,
+        String, // Database
+        String, // Store
+    ),
+
+    CloseDatabase(
+        IpcSender<Result<(), ()>>,
+        ImmutableOrigin,
+        String, // Database
+    ),
+
+    OpenDatabase(
+        IpcSender<u64>, // Returns the version
+        ImmutableOrigin,
+        String,      // Database
+        Option<u64>, // Eventual version
+    ),
+
+    // Deletes the database
+    DeleteDatabase(
+        IpcSender<Result<(), ()>>,
+        ImmutableOrigin,
+        String, // Database
+    ),
+
+    // Returns an unique identifier that is used to be able to
+    // commit/abort transactions.
+    RegisterNewTxn(
+        IpcSender<u64>,
+        ImmutableOrigin,
+        String, // Database
+    ),
+
+    // Starts executing the requests of a transaction
+    // https://www.w3.org/TR/IndexedDB-2/#transaction-start
+    StartTransaction(
+        IpcSender<Result<(), ()>>,
+        ImmutableOrigin,
+        String, // Database
+        u64,    // The serial number of the mutating transaction
+    ),
+
+    // Returns the version of the database
+    Version(
+        IpcSender<u64>,
+        ImmutableOrigin,
+        String, // Database
+    ),
+
+    /// Send a reply when done cleaning up thread resources and then shut it down
+    Exit(IpcSender<IndexedDBThreadReturnType>),
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+pub enum IndexedDBThreadMsg {
+    Sync(SyncOperation),
+    Async(
+        IpcSender<Option<Vec<u8>>>, // Sender to send the result of the async operation
+        ImmutableOrigin,
+        String, // Database
+        String, // ObjectStore
+        u64,    // Serial number of the transaction that requests this operation
+        IndexedDBTxnMode,
+        AsyncOperation,
+    ),
+}

components/shared/net/lib.rs

@@ -32,6 +32,7 @@ use servo_url::{ImmutableOrigin, ServoUrl};
 
 use crate::filemanager_thread::FileManagerThreadMsg;
 use crate::http_status::HttpStatus;
+use crate::indexeddb_thread::IndexedDBThreadMsg;
 use crate::request::{Request, RequestBuilder};
 use crate::response::{HttpsState, Response, ResponseInit};
 use crate::storage_thread::StorageThreadMsg;
@@ -40,6 +41,7 @@ pub mod blob_url_store;
 pub mod filemanager_thread;
 pub mod http_status;
 pub mod image_cache;
+pub mod indexeddb_thread;
 pub mod mime_classifier;
 pub mod policy_container;
 pub mod pub_domains;
@@ -414,13 +416,19 @@ where
 pub struct ResourceThreads {
     pub core_thread: CoreResourceThread,
     storage_thread: IpcSender<StorageThreadMsg>,
+    idb_thread: IpcSender<IndexedDBThreadMsg>,
 }
 
 impl ResourceThreads {
-    pub fn new(c: CoreResourceThread, s: IpcSender<StorageThreadMsg>) -> ResourceThreads {
+    pub fn new(
+        c: CoreResourceThread,
+        s: IpcSender<StorageThreadMsg>,
+        i: IpcSender<IndexedDBThreadMsg>,
+    ) -> ResourceThreads {
         ResourceThreads {
             core_thread: c,
             storage_thread: s,
+            idb_thread: i,
         }
     }
 
@@ -439,6 +447,16 @@ impl IpcSend<CoreResourceMsg> for ResourceThreads {
     }
 }
 
+impl IpcSend<IndexedDBThreadMsg> for ResourceThreads {
+    fn send(&self, msg: IndexedDBThreadMsg) -> IpcSendResult {
+        self.idb_thread.send(msg)
+    }
+
+    fn sender(&self) -> IpcSender<IndexedDBThreadMsg> {
+        self.idb_thread.clone()
+    }
+}
+
 impl IpcSend<StorageThreadMsg> for ResourceThreads {
     fn send(&self, msg: StorageThreadMsg) -> IpcSendResult {
         self.storage_thread.send(msg)