Add new withRetryingConnectionBody function to retry a function body …

…with an active Connection

Sources/MassTransit/Utils/withRetryingConnectionBody.swift

@@ -0,0 +1,53 @@
+import AMQPClient
+import Logging
+import RabbitMq
+
+func withRetryingConnectionBody(
+    _ connection: Connection,
+    operationName: String,
+    retryInterval: Duration = MassTransit.defaultRetryInterval,
+    exitOnSuccess: Bool = false,
+    body: @escaping @Sendable () async throws -> Void
+) async throws {
+    var firstAttempt = true
+    let firstAttemptStart = ContinuousClock().now
+
+    // Wait for connection, timeout after retryInterval
+    await connection.waitForConnection(timeout: retryInterval)
+
+    while !Task.isCancelledOrShuttingDown {
+        do {
+            connection.logger.trace("Starting body for operation \"\(operationName)\"...")
+            try await body()
+            if exitOnSuccess {
+                return
+            }
+        } catch AMQPConnectionError.connectionClosed(let replyCode, let replyText) {
+            if !firstAttempt {
+                let error = AMQPConnectionError.connectionClosed(replyCode: replyCode, replyText: replyText)
+                connection.logger.error(
+                    "Connection closed while \(operationName): \(error)"
+                )
+            }
+
+            // Wait for connection, timeout after retryInterval
+            await connection.waitForConnection(timeout: retryInterval)
+
+            firstAttempt = false
+            continue
+        } catch {
+            // If this is our first attempt to connect, keep trying until we reach the timeout
+            if firstAttempt && ContinuousClock().now - firstAttemptStart < retryInterval {
+                await gracefulCancellableDelay(connection.connectionPollingInterval)
+                continue
+            }
+
+            connection.logger.error("Error \(operationName): \(error)")
+            firstAttempt = false
+        }
+
+        // Retry here
+        connection.logger.trace("Will retry operation \"\(operationName)\" in \(retryInterval)...")
+        try await Task.sleep(for: retryInterval)
+    }
+}