1 files changed, 132 insertions, 0 deletions
diff --git a/src/msg/Policy.h b/src/msg/Policy.h
new file mode 100644
index 000000000..0cfa03aee
--- /dev/null
+++ b/src/msg/Policy.h
@@ -0,0 +1,132 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#pragma once
+
+#include "include/ceph_features.h"
+
+namespace ceph::net {
+
+using peer_type_t = int;
+
+/**
+ * A Policy describes the rules of a Connection. Is there a limit on how
+ * much data this Connection can have locally? When the underlying connection
+ * experiences an error, does the Connection disappear? Can this Messenger
+ * re-establish the underlying connection?
+ */
+template<class ThrottleType>
+struct Policy {
+  /// If true, the Connection is tossed out on errors.
+  bool lossy;
+  /// If true, the underlying connection can't be re-established from this end.
+  bool server;
+  /// If true, we will standby when idle
+  bool standby;
+  /// If true, we will try to detect session resets
+  bool resetcheck;
+
+  /// Server: register lossy client connections.
+  bool register_lossy_clients = true;
+  // The net result of this is that a given client can only have one
+  // open connection with the server.  If a new connection is made,
+  // the old (registered) one is closed by the messenger during the accept
+  // process.
+  
+  /**
+   *  The throttler is used to limit how much data is held by Messages from
+   *  the associated Connection(s). When reading in a new Message, the Messenger
+   *  will call throttler->throttle() for the size of the new Message.
+   */
+  ThrottleType* throttler_bytes;
+  ThrottleType* throttler_messages;
+  
+  /// Specify features supported locally by the endpoint.
+#ifdef MSG_POLICY_UNIT_TESTING
+  uint64_t features_supported{CEPH_FEATURES_SUPPORTED_DEFAULT};
+#else
+  static constexpr uint64_t features_supported{CEPH_FEATURES_SUPPORTED_DEFAULT};
+#endif
+
+  /// Specify features any remotes must have to talk to this endpoint.
+  uint64_t features_required;
+  
+  Policy()
+    : lossy(false), server(false), standby(false), resetcheck(true),
+      throttler_bytes(NULL),
+      throttler_messages(NULL),
+      features_required(0) {}
+private:
+  Policy(bool l, bool s, bool st, bool r, bool rlc, uint64_t req)
+    : lossy(l), server(s), standby(st), resetcheck(r),
+      register_lossy_clients(rlc),
+      throttler_bytes(NULL),
+      throttler_messages(NULL),
+      features_required(req) {}
+  
+public:
+  static Policy stateful_server(uint64_t req) {
+    return Policy(false, true, true, true, true, req);
+  }
+  static Policy stateless_registered_server(uint64_t req) {
+    return Policy(true, true, false, false, true, req);
+  }
+  static Policy stateless_server(uint64_t req) {
+    return Policy(true, true, false, false, false, req);
+  }
+  static Policy lossless_peer(uint64_t req) {
+    return Policy(false, false, true, false, true, req);
+  }
+  static Policy lossless_peer_reuse(uint64_t req) {
+    return Policy(false, false, true, true, true, req);
+  }
+  static Policy lossy_client(uint64_t req) {
+    return Policy(true, false, false, false, true, req);
+  }
+  static Policy lossless_client(uint64_t req) {
+    return Policy(false, false, false, true, true, req);
+  }
+};
+
+template<class ThrottleType>
+class PolicySet {
+  using policy_t = Policy<ThrottleType> ;
+  /// the default Policy we use for Pipes
+  policy_t default_policy;
+  /// map specifying different Policies for specific peer types
+  std::map<int, policy_t> policy_map; // entity_name_t::type -> Policy
+
+public:
+  const policy_t& get(peer_type_t peer_type) const {
+    if (auto found = policy_map.find(peer_type); found != policy_map.end()) {
+      return found->second;
+    } else {
+      return default_policy;
+    }
+  }
+  policy_t& get(peer_type_t peer_type) {
+    if (auto found = policy_map.find(peer_type); found != policy_map.end()) {
+      return found->second;
+    } else {
+      return default_policy;
+    }
+  }
+  void set(peer_type_t peer_type, const policy_t& p) {
+    policy_map[peer_type] = p;
+  }
+  const policy_t& get_default() const {
+    return default_policy;
+  }
+  void set_default(const policy_t& p) {
+    default_policy = p;
+  }
+  void set_throttlers(peer_type_t peer_type,
+                      ThrottleType* byte_throttle,
+                      ThrottleType* msg_throttle) {
+    auto& policy = get(peer_type);
+    policy.throttler_bytes = byte_throttle;
+    policy.throttler_messages = msg_throttle;
+  }
+};
+
+}