initial code repo
[stor4nfv.git] / src / ceph / src / os / filestore / Journal.h
diff --git a/src/ceph/src/os/filestore/Journal.h b/src/ceph/src/os/filestore/Journal.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) 2004-2006 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.
+ *
+ */
+
+
+#ifndef CEPH_JOURNAL_H
+#define CEPH_JOURNAL_H
+
+#include <errno.h>
+
+#include "include/buffer_fwd.h"
+#include "include/Context.h"
+#include "common/Finisher.h"
+#include "common/TrackedOp.h"
+#include "os/ObjectStore.h"
+#include "common/zipkin_trace.h"
+
+class PerfCounters;
+
+class Journal {
+protected:
+  uuid_d fsid;
+  Finisher *finisher;
+public:
+  CephContext* cct;
+  PerfCounters *logger;
+protected:
+  Cond *do_sync_cond;
+  bool wait_on_full;
+
+public:
+  Journal(CephContext* cct, uuid_d f, Finisher *fin, Cond *c=0) :
+    fsid(f), finisher(fin), cct(cct), logger(NULL),
+    do_sync_cond(c),
+    wait_on_full(false) { }
+  virtual ~Journal() { }
+
+  virtual int check() = 0;   ///< check if journal appears valid
+  virtual int create() = 0;  ///< create a fresh journal
+  virtual int open(uint64_t fs_op_seq) = 0;  ///< open an existing journal
+  virtual void close() = 0;  ///< close an open journal
+
+  virtual void flush() = 0;
+
+  /**
+   * reserve_throttle_and_backoff
+   *
+   * Implementation may throttle or backoff based on ops
+   * reserved here but not yet released using committed_thru.
+   */
+  virtual void reserve_throttle_and_backoff(uint64_t count) = 0;
+
+  virtual int dump(ostream& out) { return -EOPNOTSUPP; }
+
+  void set_wait_on_full(bool b) { wait_on_full = b; }
+
+  // writes
+  virtual bool is_writeable() = 0;
+  virtual int make_writeable() = 0;
+  virtual void submit_entry(uint64_t seq, bufferlist& e, uint32_t orig_len,
+                           Context *oncommit,
+                           TrackedOpRef osd_op = TrackedOpRef()) = 0;
+  virtual void commit_start(uint64_t seq) = 0;
+  virtual void committed_thru(uint64_t seq) = 0;
+
+  /// Read next journal entry - asserts on invalid journal
+  virtual bool read_entry(
+    bufferlist &bl, ///< [out] payload on successful read
+    uint64_t &seq   ///< [in,out] sequence number on last successful read
+    ) = 0; ///< @return true on successful read, false on journal end
+
+  virtual bool should_commit_now() = 0;
+
+  virtual int prepare_entry(vector<ObjectStore::Transaction>& tls, bufferlist* tbl) = 0;
+
+  virtual off64_t get_journal_size_estimate() { return 0; }
+
+  // reads/recovery
+
+};
+
+#endif