initial code repo

[stor4nfv.git] / src / ceph / src / os / filestore / IndexManager.h

diff --git a/src/ceph/src/os/filestore/IndexManager.h b/src/ceph/src/os/filestore/IndexManager.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 OS_INDEXMANAGER_H
+#define OS_INDEXMANAGER_H
+
+#include "include/memory.h"
+#include "include/unordered_map.h"
+
+#include "common/Mutex.h"
+#include "common/Cond.h"
+#include "common/config.h"
+#include "common/debug.h"
+
+#include "CollectionIndex.h"
+#include "HashIndex.h"
+
+
+/// Public type for Index
+struct Index {
+  CollectionIndex *index;
+
+  Index() : index(NULL) {}
+  explicit Index(CollectionIndex* index) : index(index) {}
+
+  CollectionIndex *operator->() { return index; }
+  CollectionIndex &operator*() { return *index; }
+};
+
+
+/**
+ * Encapsulates mutual exclusion for CollectionIndexes.
+ *
+ * Allowing a modification (removal or addition of an object) to occur
+ * while a read is occuring (lookup of an object's path and use of
+ * that path) may result in the path becoming invalid.  Thus, during
+ * the lifetime of a CollectionIndex object and any paths returned
+ * by it, no other concurrent accesses may be allowed.
+ * This is enforced by using CollectionIndex::access_lock
+ */
+class IndexManager {
+  CephContext* cct;
+  RWLock lock; ///< Lock for Index Manager
+  bool upgrade;
+  ceph::unordered_map<coll_t, CollectionIndex* > col_indices;
+
+  /**
+   * Index factory
+   *
+   * Encapsulates logic for handling legacy FileStore
+   * layouts
+   *
+   * @param [in] c Collection for which to get index
+   * @param [in] path Path to collection
+   * @param [out] index Index for c
+   * @return error code
+   */
+  int build_index(coll_t c, const char *path, CollectionIndex **index);
+  bool get_index_optimistic(coll_t c, Index *index);
+public:
+  /// Constructor
+  explicit IndexManager(CephContext* cct,
+                       bool upgrade) : cct(cct),
+                                       lock("IndexManager lock"),
+                                       upgrade(upgrade) {}
+
+  ~IndexManager();
+
+  /**
+   * Reserve and return index for c
+   *
+   * @param [in] c Collection for which to get index
+   * @param [in] baseDir base directory of collections
+   * @param [out] index Index for c
+   * @return error code
+   */
+  int get_index(coll_t c, const string& baseDir, Index *index);
+
+  /**
+   * Initialize index for collection c at path
+   *
+   * @param [in] c Collection for which to init Index
+   * @param [in] path Path to collection
+   * @param [in] filestore_version version of containing FileStore
+   * @return error code
+   */
+  int init_index(coll_t c, const char *path, uint32_t filestore_version);
+};
+
+#endif