Adding upstream version 2.2.0.upstream/2.2.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 143 insertions, 0 deletions

diff --git a/src/lib/util/reconnect_ctl.h b/src/lib/util/reconnect_ctl.h
new file mode 100644
index 0000000..b9f4a32
--- /dev/null
+++ b/src/lib/util/reconnect_ctl.h
@@ -0,0 +1,143 @@
+// Copyright (C) 2022 Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 http://mozilla.org/MPL/2.0/.
+
+#ifndef RECONNECT_CTL_H
+#define RECONNECT_CTL_H
+
+#include <string>
+#include <boost/shared_ptr.hpp>
+
+namespace isc {
+namespace util {
+
+/// @brief Type of action to take on connection loss.
+enum class OnFailAction {
+    STOP_RETRY_EXIT,
+    SERVE_RETRY_EXIT,
+    SERVE_RETRY_CONTINUE
+};
+
+/// @brief Warehouses reconnect control values
+///
+/// When any connection loses connectivity to its backend, it
+/// creates an instance of this class based on its configuration parameters and
+/// passes the instance into connection's lost callback.  This allows
+/// the layer(s) above the connection to know how to proceed.
+///
+class ReconnectCtl {
+public:
+    /// @brief Constructor.
+    ///
+    /// @param backend_type type of the caller backend.
+    /// @param timer_name timer associated to this object.
+    /// @param max_retries maximum number of reconnect attempts to make.
+    /// @param retry_interval amount of time to between reconnect attempts.
+    /// @param action which should be taken on connection loss.
+    ReconnectCtl(const std::string& backend_type, const std::string& timer_name,
+                 unsigned int max_retries, unsigned int retry_interval,
+                 OnFailAction action) :
+          backend_type_(backend_type), timer_name_(timer_name),
+          max_retries_(max_retries), retries_left_(max_retries),
+          retry_interval_(retry_interval), action_(action) {}
+
+    /// @brief Returns the type of the caller backend.
+    std::string backendType() const {
+        return (backend_type_);
+    }
+
+    /// @brief Returns the associated timer name.
+    ///
+    /// @return the associated timer.
+    std::string timerName() const {
+        return (timer_name_);
+    }
+
+    /// @brief Decrements the number of retries remaining
+    ///
+    /// Each call decrements the number of retries by one until zero is reached.
+    /// @return true the number of retries remaining is greater than zero.
+    bool checkRetries() {
+        return (retries_left_ ? --retries_left_ : false);
+    }
+
+    /// @brief Returns the maximum number of retries allowed.
+    unsigned int maxRetries() const {
+        return (max_retries_);
+    }
+
+    /// @brief Returns the number for retries remaining.
+    unsigned int retriesLeft() const {
+        return (retries_left_);
+    }
+
+    /// @brief Returns an index of current retry.
+    unsigned int retryIndex() const {
+        return (max_retries_ - retries_left_);
+    }
+
+    /// @brief Returns the amount of time to wait between reconnect attempts.
+    unsigned int retryInterval() const {
+        return (retry_interval_);
+    }
+
+    /// @brief Resets the retries count.
+    void resetRetries() {
+        retries_left_ = max_retries_;
+    }
+
+    /// @brief Return true if the connection loss should affect the service,
+    /// false otherwise
+    bool alterServiceState() const {
+        return (action_ == OnFailAction::STOP_RETRY_EXIT);
+    }
+
+    /// @brief Return true if the connection recovery mechanism should shut down
+    /// the server on failure, false otherwise.
+    bool exitOnFailure() const {
+        return ((action_ == OnFailAction::STOP_RETRY_EXIT) ||
+                (action_ == OnFailAction::SERVE_RETRY_EXIT));
+    }
+
+    /// @brief Convert action to string.
+    ///
+    /// @param action The action type to be converted to text.
+    /// @return The text representation of the action type.
+    static std::string onFailActionToText(OnFailAction action);
+
+    /// @brief Convert string to action.
+    ///
+    /// @param text The text to be converted to action type.
+    /// @return The action type corresponding to the text representation.
+    static OnFailAction onFailActionFromText(const std::string& text);
+
+private:
+
+    /// @brief Caller backend type.
+    const std::string backend_type_;
+
+    /// @brief Timer associated to this object.
+    std::string timer_name_;
+
+    /// @brief Maximum number of retry attempts to make.
+    unsigned int max_retries_;
+
+    /// @brief Number of attempts remaining.
+    unsigned int retries_left_;
+
+    /// @brief The amount of time to wait between reconnect attempts.
+    unsigned int retry_interval_;
+
+    /// @brief Action to take on connection loss.
+    OnFailAction action_;
+};
+
+/// @brief Pointer to an instance of ReconnectCtl
+typedef boost::shared_ptr<ReconnectCtl> ReconnectCtlPtr;
+
+}
+}
+
+#endif // RECONNECT_CTL_H