untyped_map_handle.h

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// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the Apache 2.0 License.
#pragma once
 
#include "ccf/kv/abstract_handle.h"
#include "ccf/kv/serialisers/serialised_entry.h"
#include "ccf/kv/version.h"
 
#include <functional>
#include <optional>
#include <string>
 
namespace ccf::kv::untyped
{
  struct ChangeSet;
 
  class MapHandle : public ccf::kv::AbstractHandle
  {
  public:
    // Expose these types so that other code can use them as MyTx::KeyType or
    // MyMap::MapHandle::KeyType, templated on the MapHandle or Map type
    using KeyType = ccf::kv::serialisers::SerialisedEntry;
    using ValueType = ccf::kv::serialisers::SerialisedEntry;
 
    using ElementVisitor =
      std::function<void(const KeyType& k, const ValueType& V)>;
 
    using ElementVisitorWithEarlyOut =
      std::function<bool(const KeyType& k, const ValueType& V)>;
 
  protected:
    ccf::kv::untyped::ChangeSet& tx_changes;
    std::string map_name;
 
    const ValueType* read_key(const KeyType& key);
 
    void foreach_state_and_writes(
      const ElementVisitorWithEarlyOut& fn, bool always_consider_writes);
 
  public:
    MapHandle(ccf::kv::untyped::ChangeSet& cs, std::string map_name);
 
    [[nodiscard]] std::string get_name_of_map() const;
 
    std::optional<ValueType> get(const KeyType& key);
 
    std::optional<Version> get_version_of_previous_write(const KeyType& key);
 
    std::optional<ValueType> get_globally_committed(const KeyType& key);
 
    bool has(const KeyType& key);
 
    bool has_globally_committed(const KeyType& key);
 
    void put(const KeyType& key, const ValueType& value);
 
    void remove(const KeyType& key);
 
    void clear();
 
    void foreach(const ElementVisitorWithEarlyOut& fn);
 
    size_t size();
 
    // Sub-range variant of foreach. Visits the range of keys in [from, to).
    void range(
      const ElementVisitor& fn,
      const std::optional<KeyType>& from,
      const std::optional<KeyType>& to);
  };
}