ceph/src/os/bluestore/Allocator.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * This is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License version 2.1, as published by the Free Software
   9  * Foundation.  See file COPYING.
  10  *
  11  */
  12 #ifndef CEPH_OS_BLUESTORE_ALLOCATOR_H
  13 #define CEPH_OS_BLUESTORE_ALLOCATOR_H
  14
  15 #include <ostream>
  16 #include "include/ceph_assert.h"
  17 #include "os/bluestore/bluestore_types.h"
  18
  19 class Allocator {
  20 public:
  21   virtual ~Allocator() {}
  22
  23   /*
  24    * Allocate required number of blocks in n number of extents.
  25    * Min and Max number of extents are limited by:
  26    * a. alloc unit
  27    * b. max_alloc_size.
  28    * as no extent can be lesser than alloc_unit and greater than max_alloc size.
  29    * Apart from that extents can vary between these lower and higher limits according
  30    * to free block search algorithm and availability of contiguous space.
  31    */
  32   virtual int64_t allocate(uint64_t want_size, uint64_t alloc_unit,
  33                            uint64_t max_alloc_size, int64_t hint,
  34                            PExtentVector *extents) = 0;
  35
  36   int64_t allocate(uint64_t want_size, uint64_t alloc_unit,
  37                    int64_t hint, PExtentVector *extents) {
  38     return allocate(want_size, alloc_unit, want_size, hint, extents);
  39   }
  40
  41   /* Bulk release. Implementations may override this method to handle the whole
  42    * set at once. This could save e.g. unnecessary mutex dance. */
  43   virtual void release(const interval_set<uint64_t>& release_set) = 0;
  44   void release(const PExtentVector& release_set);
  45
  46   virtual void dump() = 0;
  47
  48   virtual void init_add_free(uint64_t offset, uint64_t length) = 0;
  49   virtual void init_rm_free(uint64_t offset, uint64_t length) = 0;
  50
  51   virtual uint64_t get_free() = 0;
  52   virtual double get_fragmentation(uint64_t alloc_unit)
  53   {
  54     return 0.0;
  55   }
  56
  57   virtual void shutdown() = 0;
  58   static Allocator *create(CephContext* cct, string type, int64_t size,
  59                            int64_t block_size);
  60 };
  61
  62 #endif