From d779175b90bc70b7f6c901cbe60c5a674caceb72 Mon Sep 17 00:00:00 2001
From: j <j@fsdfsd.net>
Date: Sat, 6 Apr 2024 02:04:28 -0400
Subject: [PATCH] SQlite Retry logic for database lock

---
 src/db/services/Database.ts | 68 ++++++++++++++++++++++++++++---------
 1 file changed, 52 insertions(+), 16 deletions(-)

diff --git a/src/db/services/Database.ts b/src/db/services/Database.ts
index 5e1b263..ef31ad2 100644
--- a/src/db/services/Database.ts
+++ b/src/db/services/Database.ts
@@ -42,14 +42,16 @@ export class DatabaseService {
      * }
      */
     public static async loadGameState(authorId: number): Promise<GameState | null> {
-        const db = await DatabaseService.getDatabase();
-        const sql = `SELECT data FROM game_state WHERE authorId = ? AND active = TRUE`;
-        const row = await db.get(sql, [authorId]);
-        if (row) {
-            return JSON.parse(row.data) as GameState;
-        } else {
-            return null;
-        }
+        return this.withRetry(async () => {
+            const db = await DatabaseService.getDatabase();
+            const sql = `SELECT data FROM game_state WHERE authorId = ? AND active = TRUE`;
+            const row = await db.get(sql, [authorId]);
+            if (row) {
+                return JSON.parse(row.data) as GameState;
+            } else {
+                return null;
+            }
+        });
     }
 
     /**
@@ -63,15 +65,17 @@ export class DatabaseService {
       * await DatabaseService.saveGameState(1, currentGameState);
       */
     public static async saveGameState(authorId: number, gameState: GameState): Promise<void> {
-        const db = await DatabaseService.getDatabase();
-        const data = JSON.stringify(gameState);
-        const sql = `
+        return this.withRetry(async () => {
+            const db = await DatabaseService.getDatabase();
+            const data = JSON.stringify(gameState);
+            const sql = `
             INSERT INTO game_state (authorId, data, active) VALUES (?, ?, TRUE)
             ON CONFLICT(authorId) DO UPDATE SET
             data = excluded.data
             WHERE active = TRUE;
-        `;
-        await db.run(sql, [authorId, data]);
+            `;
+            await db.run(sql, [authorId, data]);
+        });
     }
 
     /**
@@ -84,9 +88,41 @@ export class DatabaseService {
      * await DatabaseService.resetGameState(1);
      */
     public static async resetGameState(authorId: number): Promise<void> {
-        const db = await DatabaseService.getDatabase();
-        const sql = `UPDATE game_state SET active = FALSE WHERE authorId = ? AND active = TRUE`;
-        await db.run(sql, [authorId]);
+        return this.withRetry(async () => {
+            const db = await this.getDatabase();
+            const sql = `UPDATE game_state SET active = FALSE WHERE authorId = ? AND active = TRUE`;
+            await db.run(sql, [authorId]);
+        });
     }
 
+    /**
+     * Attempts to execute a database operation with retries on failure.
+     * This method is designed to handle SQLITE_BUSY errors by retrying the operation
+     * with an exponential backoff strategy. This is particularly useful for handling
+     * cases where the SQLite database is locked due to concurrent access attempts.
+     *
+     * @param operation A function that performs the database operation and returns a Promise.
+     * @param maxRetries The maximum number of retries before giving up. Defaults to 5.
+     * @param delay The initial delay (in milliseconds) before the first retry. This delay is doubled with each retry.
+     * @returns A Promise that resolves with the result of the operation, or rejects if the operation fails after all retries.
+     * @throws Will throw an error if the operation cannot be completed successfully within the allowed number of retries.
+     */
+    private static async withRetry<T>(operation: () => Promise<T>, maxRetries: number = 5, delay: number = 100): Promise<T> {
+        for (let i = 0; i < maxRetries; i++) {
+            try {
+                return await operation();
+            } catch (error) {
+                console.log('Error', error)
+                // Type check or assertion to handle the error as an object with a 'code' property
+                const e = error as { code?: string };
+                if (e.code === 'SQLITE_BUSY') {
+                    console.log(`Database is busy, retrying... Attempt ${i + 1}`);
+                    await new Promise(resolve => setTimeout(resolve, delay * Math.pow(2, i)));
+                } else {
+                    throw error; // Rethrow if it's not an SQLITE_BUSY error
+                }
+            }
+        }
+        throw new Error('Max retries reached for database operation');
+    }
 }