1 files changed, 118 insertions, 0 deletions
diff --git a/src/rgw/services/svc_mdlog.h b/src/rgw/services/svc_mdlog.h
new file mode 100644
index 000000000..57103efb4
--- /dev/null
+++ b/src/rgw/services/svc_mdlog.h
@@ -0,0 +1,118 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab ft=cpp
+
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2019 Red Hat, Inc.
+ *
+ * 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.
+ *
+ */
+
+
+#pragma once
+
+#include "rgw/rgw_service.h"
+#include "rgw/rgw_period_history.h"
+#include "rgw/rgw_period_puller.h"
+
+#include "svc_meta_be.h"
+
+
+class RGWMetadataLog;
+class RGWMetadataLogHistory;
+class RGWCoroutine;
+
+class RGWSI_Zone;
+class RGWSI_SysObj;
+class RGWSI_RADOS;
+
+namespace mdlog {
+  class ReadHistoryCR;
+  class WriteHistoryCR;
+}
+
+class RGWSI_MDLog : public RGWServiceInstance
+{
+  friend class mdlog::ReadHistoryCR;
+  friend class mdlog::WriteHistoryCR;
+
+  // maintain a separate metadata log for each period
+  std::map<std::string, RGWMetadataLog> md_logs;
+
+  // use the current period's log for mutating operations
+  RGWMetadataLog* current_log{nullptr};
+
+  bool run_sync;
+
+  // pulls missing periods for period_history
+  std::unique_ptr<RGWPeriodPuller> period_puller;
+  // maintains a connected history of periods
+  std::unique_ptr<RGWPeriodHistory> period_history;
+
+public:
+  RGWSI_MDLog(CephContext *cct, bool run_sync);
+  virtual ~RGWSI_MDLog();
+
+  struct Svc {
+    RGWSI_RADOS *rados{nullptr};
+    RGWSI_Zone *zone{nullptr};
+    RGWSI_SysObj *sysobj{nullptr};
+    RGWSI_MDLog *mdlog{nullptr};
+    RGWSI_Cls *cls{nullptr};
+  } svc;
+
+  int init(RGWSI_RADOS *_rados_svc,
+           RGWSI_Zone *_zone_svc,
+           RGWSI_SysObj *_sysobj_svc,
+           RGWSI_Cls *_cls_svc);
+
+  int do_start(optional_yield y, const DoutPrefixProvider *dpp) override;
+
+  // traverse all the way back to the beginning of the period history, and
+  // return a cursor to the first period in a fully attached history
+  RGWPeriodHistory::Cursor find_oldest_period(const DoutPrefixProvider *dpp, optional_yield y);
+
+  /// initialize the oldest log period if it doesn't exist, and attach it to
+  /// our current history
+  RGWPeriodHistory::Cursor init_oldest_log_period(optional_yield y, const DoutPrefixProvider *dpp);
+
+  /// read the oldest log period, and return a cursor to it in our existing
+  /// period history
+  RGWPeriodHistory::Cursor read_oldest_log_period(optional_yield y, const DoutPrefixProvider *dpp) const;
+
+  /// read the oldest log period asynchronously and write its result to the
+  /// given cursor pointer
+  RGWCoroutine* read_oldest_log_period_cr(const DoutPrefixProvider *dpp, 
+                                          RGWPeriodHistory::Cursor *period,
+                                          RGWObjVersionTracker *objv) const;
+
+  /// try to advance the oldest log period when the given period is trimmed,
+  /// using a rados lock to provide atomicity
+  RGWCoroutine* trim_log_period_cr(const DoutPrefixProvider *dpp, 
+                                   RGWPeriodHistory::Cursor period,
+                                   RGWObjVersionTracker *objv) const;
+  int read_history(RGWMetadataLogHistory *state, RGWObjVersionTracker *objv_tracker,optional_yield y, const DoutPrefixProvider *dpp) const;
+  int write_history(const DoutPrefixProvider *dpp, 
+                    const RGWMetadataLogHistory& state,
+                    RGWObjVersionTracker *objv_tracker,
+		    optional_yield y, bool exclusive = false);
+
+  int add_entry(const DoutPrefixProvider *dpp, const string& hash_key, const string& section, const string& key, bufferlist& bl);
+
+  int get_shard_id(const string& hash_key, int *shard_id);
+
+  RGWPeriodHistory *get_period_history() {
+    return period_history.get();
+  }
+
+  int pull_period(const DoutPrefixProvider *dpp, const std::string& period_id, RGWPeriod& period, optional_yield y);
+
+  /// find or create the metadata log for the given period
+  RGWMetadataLog* get_log(const std::string& period);
+};
+