ceph/src/crimson/os/seastore/onode_manager/simple-fltree/onode_block.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include <cstdint>
   5 #include <boost/container/small_vector.hpp>
   6
   7 #include "crimson/os/seastore/transaction_manager.h"
   8 #include "onode_delta.h"
   9
  10 namespace crimson::os::seastore {
  11
  12 // TODO s/CachedExtent/LogicalCachedExtent/
  13 struct OnodeBlock final : LogicalCachedExtent {
  14   using Ref = TCachedExtentRef<OnodeBlock>;
  15
  16   template <typename... T>
  17   OnodeBlock(T&&... t) : LogicalCachedExtent(std::forward<T>(t)...) {}
  18   OnodeBlock(OnodeBlock&& block) = delete;
  19   OnodeBlock(const OnodeBlock& block, CachedExtent::share_buffer_t tag) noexcept
  20     : LogicalCachedExtent{block, tag},
  21       share_buffer{true}
  22   {}
  23
  24   CachedExtentRef duplicate_for_write() final {
  25     return new OnodeBlock{*this, CachedExtent::share_buffer_t{}};
  26   }
  27
  28   // could materialize the pending changes to the underlying buffer here,
  29   // but since we write the change to the buffer immediately, let skip
  30   // this for now.
  31   void prepare_write() final {}
  32
  33   // queries
  34   static constexpr extent_types_t TYPE = extent_types_t::ONODE_BLOCK;
  35   extent_types_t get_type() const final {
  36     return TYPE;
  37   }
  38
  39   // have to stash all the changes before on_delta_write() is called,
  40   // otherwise we could pollute the extent with pending mutations
  41   // before the transaction carrying these mutations is committed to
  42   // disk
  43   ceph::bufferlist get_delta() final;
  44   void logical_on_delta_write() final;
  45   void apply_delta(const ceph::bufferlist &bl) final;
  46
  47   void sync() {
  48     apply_pending_changes(false);
  49   }
  50   void mutate(delta_t&& d);
  51   using mutate_func_t = std::function<void (char*, const delta_t&)>;
  52   void set_delta_applier(mutate_func_t&& func) {
  53     mutate_func = std::move(func);
  54   }
  55 private:
  56   // before looking at the extent, we need to make sure the content is up to date
  57   void apply_pending_changes(bool do_cleanup);
  58   // assuming we don't stash too many deltas to a single block
  59   // otherwise a fullwrite op is necessary
  60   boost::container::small_vector<std::unique_ptr<delta_t>, 2> deltas;
  61   mutate_func_t mutate_func;
  62   bool share_buffer = false;
  63 };
  64
  65 }