MRB webassembly

MesaFabApproval.API/Services/DalService.cs

@@ -0,0 +1,89 @@
+using System.Data;
+
+using Dapper;
+
+namespace MesaFabApproval.API.Services;
+
+public interface IDalService {
+    Task<IEnumerable<T>> QueryAsync<T>(string sql);
+    Task<int> ExecuteAsync(string sql);
+}
+
+public class DalService : IDalService {
+    private static readonly int RETRIES = 3;
+    private static readonly int BACKOFF_SECONDS_INTERVAL = 30;
+
+    private readonly ILogger<DalService> _logger;
+    private readonly IDbConnectionService _dbConnectionService;
+
+    public DalService(IDbConnectionService dbConnectionService, ILogger<DalService> logger) {
+        _dbConnectionService = dbConnectionService ??
+            throw new ArgumentNullException("IDbConnectionService not injected");
+        _logger = logger ??
+            throw new ArgumentNullException("ILogger not injected");
+    }
+
+    public async Task<IEnumerable<T>> QueryAsync<T>(string sql) {
+        if (sql is null) throw new ArgumentNullException("sql cannot be null");
+
+        int remainingRetries = RETRIES;
+        bool queryWasSuccessful = false;
+        Exception exception = null;
+        IEnumerable<T> result = new List<T>();
+        while (!queryWasSuccessful && remainingRetries > 0) {
+            int backoffSeconds = (RETRIES - remainingRetries--) * BACKOFF_SECONDS_INTERVAL;
+            Task.Delay(backoffSeconds * 1000).Wait();
+
+            try {
+                _logger.LogInformation($"Attempting to perform query with {sql}. Remaining retries: {remainingRetries}");
+
+                using (IDbConnection conn = _dbConnectionService.GetConnection()) {
+                    result = await conn.QueryAsync<T>(sql);
+                }
+
+                queryWasSuccessful = true;
+            } catch (Exception ex) {
+                _logger.LogError($"An exception occurred while attempting to perform a query. Exception: {ex.Message}");
+                exception = ex;
+            }
+        }
+
+        if (!queryWasSuccessful && exception is not null) {
+            throw exception;
+        }
+
+        return result;
+    }
+
+    public async Task<int> ExecuteAsync(string sql) {
+        if (sql is null) throw new ArgumentNullException("sql cannot be null");
+
+        int remainingRetries = RETRIES;
+        bool queryWasSuccessful = false;
+        Exception exception = null;
+        int rowsAffected = 0;
+        while (!queryWasSuccessful && remainingRetries > 0) {
+            int backoffSeconds = (RETRIES - remainingRetries--) * BACKOFF_SECONDS_INTERVAL;
+            Task.Delay(backoffSeconds * 1000).Wait();
+
+            try {
+                _logger.LogInformation($"Attempting to execute {sql}. Remaining retries: {remainingRetries}");
+
+                using (IDbConnection conn = _dbConnectionService.GetConnection()) {
+                    rowsAffected = await conn.ExecuteAsync(sql);
+                }
+
+                queryWasSuccessful = true;
+            } catch (Exception ex) {
+                _logger.LogError($"An exception occurred while attempting to execute a query. Exception: {ex.Message}");
+                exception = ex;
+            }
+        }
+
+        if (!queryWasSuccessful && exception is not null) {
+            throw exception;
+        }
+
+        return rowsAffected;
+    }
+}