initial code repo

[stor4nfv.git] / src / ceph / src / messages / MForward.h

diff --git a/src/ceph/src/messages/MForward.h b/src/ceph/src/messages/MForward.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2010 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ * Client requests often need to get forwarded from some monitor
+ * to the leader. This class encapsulates the original message
+ * along with the client's caps so the leader can do proper permissions
+ * checking.
+ */
+
+#ifndef CEPH_MFORWARD_H
+#define CEPH_MFORWARD_H
+
+#include "msg/Message.h"
+#include "mon/MonCap.h"
+#include "include/encoding.h"
+#include "include/stringify.h"
+
+struct MForward : public Message {
+  uint64_t tid;
+  entity_inst_t client;
+  MonCap client_caps;
+  uint64_t con_features;
+  EntityName entity_name;
+  PaxosServiceMessage *msg;   // incoming or outgoing message
+
+  string msg_desc;  // for operator<< only
+  
+  static const int HEAD_VERSION = 3;
+  static const int COMPAT_VERSION = 3;
+
+  MForward() : Message(MSG_FORWARD, HEAD_VERSION, COMPAT_VERSION),
+               tid(0), con_features(0), msg(NULL) {}
+  //the message needs to have caps filled in!
+  MForward(uint64_t t, PaxosServiceMessage *m, uint64_t feat) :
+    Message(MSG_FORWARD, HEAD_VERSION, COMPAT_VERSION),
+    tid(t), msg(NULL) {
+    client = m->get_source_inst();
+    client_caps = m->get_session()->caps;
+    con_features = feat;
+    // we may need to reencode for the target mon
+    msg->clear_payload();
+    msg = (PaxosServiceMessage*)m->get();
+  }
+  MForward(uint64_t t, PaxosServiceMessage *m, uint64_t feat,
+           const MonCap& caps) :
+    Message(MSG_FORWARD, HEAD_VERSION, COMPAT_VERSION),
+    tid(t), client_caps(caps), msg(NULL) {
+    client = m->get_source_inst();
+    con_features = feat;
+    msg = (PaxosServiceMessage*)m->get();
+  }
+private:
+  ~MForward() override {
+    if (msg) {
+      // message was unclaimed
+      msg->put();
+      msg = NULL;
+    }
+  }
+
+public:
+  void encode_payload(uint64_t features) override {
+    ::encode(tid, payload);
+    ::encode(client, payload, features);
+    ::encode(client_caps, payload, features);
+    // Encode client message with intersection of target and source
+    // features.  This could matter if the semantics of the encoded
+    // message are changed when reencoding with more features than the
+    // client had originally.  That should never happen, but we may as
+    // well be defensive here.
+    if (con_features != features) {
+      msg->clear_payload();
+    }
+    encode_message(msg, features & con_features, payload);
+    ::encode(con_features, payload);
+    ::encode(entity_name, payload);
+  }
+
+  void decode_payload() override {
+    bufferlist::iterator p = payload.begin();
+    ::decode(tid, p);
+    ::decode(client, p);
+    ::decode(client_caps, p);
+    msg = (PaxosServiceMessage *)decode_message(NULL, 0, p);
+    ::decode(con_features, p);
+    ::decode(entity_name, p);
+  }
+
+  PaxosServiceMessage *claim_message() {
+    // let whoever is claiming the message deal with putting it.
+    assert(msg);
+    msg_desc = stringify(*msg);
+    PaxosServiceMessage *m = msg;
+    msg = NULL;
+    return m;
+  }
+
+  const char *get_type_name() const override { return "forward"; }
+  void print(ostream& o) const override {
+    o << "forward(";
+    if (msg) {
+      o << *msg;
+    } else {
+      o << msg_desc;
+    }
+    o << " caps " << client_caps
+      << " tid " << tid
+      << " con_features " << con_features << ")";
+  }
+};
+  
+#endif