From 12add19c314a9d8f708d44f976718913e9adaac4 Mon Sep 17 00:00:00 2001
From: Bruno Windels <bruno@windels.cloud>
Date: Tue, 21 Sep 2021 21:02:39 +0200
Subject: [PATCH] add Store.tryAdd, which prevent abort on ConstraintError

---
 src/matrix/storage/idb/Store.ts | 15 ++++++++++++++-
 src/matrix/storage/idb/error.ts | 12 ++++++++++--
 src/matrix/storage/idb/utils.ts |  6 +++---
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/matrix/storage/idb/Store.ts b/src/matrix/storage/idb/Store.ts
index 42a41ae6..4a018d23 100644
--- a/src/matrix/storage/idb/Store.ts
+++ b/src/matrix/storage/idb/Store.ts
@@ -15,7 +15,7 @@ limitations under the License.
 */
 
 import {QueryTarget, IDBQuery} from "./QueryTarget";
-import {IDBRequestAttemptError} from "./error";
+import {IDBRequestError, IDBRequestAttemptError} from "./error";
 import {reqAsPromise} from "./utils";
 import {Transaction} from "./Transaction";
 import {LogItem} from "../../../logging/LogItem.js";
@@ -169,6 +169,19 @@ export class Store<T> extends QueryTarget<T> {
         const request = this._idbStore.add(value);
         this._prepareErrorLog(request, log, "add", undefined, value);
     }
+    
+    async tryAdd(value: T, log: LogItem): Promise<boolean> {
+        try {
+            await reqAsPromise(this._idbStore.add(value));
+            return true;
+        } catch (err) {
+            if (err instanceof IDBRequestError) {
+                log.log({l: "could not write", id: this._getKey(value), e: err}, log.level.Warn);
+                err.preventTransactionAbort();
+            }
+            return false;
+        }
+    }
 
     delete(keyOrKeyRange: IDBValidKey | IDBKeyRange, log?: LogItem): void {
         // ok to not monitor result of request, see comment in `put`.
diff --git a/src/matrix/storage/idb/error.ts b/src/matrix/storage/idb/error.ts
index 388ad4c0..fb602168 100644
--- a/src/matrix/storage/idb/error.ts
+++ b/src/matrix/storage/idb/error.ts
@@ -57,10 +57,18 @@ export class IDBError extends StorageError {
 }
 
 export class IDBRequestError extends IDBError {
-    constructor(request: IDBRequest, message: string = "IDBRequest failed") {
+    private errorEvent: Event;
+
+    constructor(errorEvent: Event) {
+        const request = errorEvent.target as IDBRequest;
         const source = request.source;
         const cause = request.error;
-        super(message, source, cause);
+        super("IDBRequest failed", source, cause);
+        this.errorEvent = errorEvent;
+    }
+
+    preventTransactionAbort() {
+        this.errorEvent.preventDefault();
     }
 }
 
diff --git a/src/matrix/storage/idb/utils.ts b/src/matrix/storage/idb/utils.ts
index f9209f56..a9432139 100644
--- a/src/matrix/storage/idb/utils.ts
+++ b/src/matrix/storage/idb/utils.ts
@@ -97,7 +97,7 @@ export function reqAsPromise<T>(req: IDBRequest<T>): Promise<T> {
             needsSyncPromise && Promise._flush && Promise._flush();
         });
         req.addEventListener("error", event => {
-            const error = new IDBRequestError(event.target as IDBRequest<T>);
+            const error = new IDBRequestError(event);
             reject(error);
             // @ts-ignore
             needsSyncPromise && Promise._flush && Promise._flush();
@@ -143,8 +143,8 @@ type CursorIterator<T, I extends IDBCursor> = (value: I extends IDBCursorWithVal
 export function iterateCursor<T, I extends IDBCursor = IDBCursorWithValue>(cursorRequest: IDBRequest<I | null>, processValue: CursorIterator<T, I>): Promise<boolean> {
     // TODO: does cursor already have a value here??
     return new Promise<boolean>((resolve, reject) => {
-        cursorRequest.onerror = () => {
-            reject(new IDBRequestError(cursorRequest));
+        cursorRequest.onerror = event => {
+            reject(new IDBRequestError(event));
             // @ts-ignore
             needsSyncPromise && Promise._flush && Promise._flush();
         };