historical_queries_interface.h

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// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the Apache 2.0 License.
#pragma once
 
#include "ccf/kv/read_only_store.h"
#include "ccf/node_subsystem_interface.h"
#include "ccf/receipt.h"
#include "ccf/seq_no_collection.h"
#include "ccf/tx_id.h"
 
#include <chrono>
#include <memory>
 
namespace ccf::historical
{
  struct State
  {
    ccf::kv::ReadOnlyStorePtr store = nullptr;
    TxReceiptImplPtr receipt = nullptr;
    ccf::TxID transaction_id;
 
    State(
      const ccf::kv::ReadOnlyStorePtr& store_,
      const TxReceiptImplPtr& receipt_,
      const ccf::TxID& transaction_id_) :
      store(store_),
      receipt(receipt_),
      transaction_id(transaction_id_)
    {}
 
    bool operator==(const State& other) const
    {
      return store == other.store && receipt == other.receipt &&
        transaction_id == other.transaction_id;
    };
  };
 
  using StatePtr = std::shared_ptr<State>;
 
  using RequestHandle = size_t;
 
  using ExpiryDuration = std::chrono::seconds;
 
  using CacheSize = size_t;
 
  class AbstractStateCache : public ccf::AbstractNodeSubSystem
  {
  public:
    virtual ~AbstractStateCache() = default;
 
    static char const* get_subsystem_name()
    {
      return "StateCache";
    }
 
    virtual void set_default_expiry_duration(
      ExpiryDuration seconds_until_expiry) = 0;
 
    virtual void set_soft_cache_limit(CacheSize cache_limit) = 0;
 
    virtual void track_deletes_on_missing_keys(bool track) = 0;
 
    virtual ccf::kv::ReadOnlyStorePtr get_store_at(
      RequestHandle handle,
      ccf::SeqNo seqno,
      ExpiryDuration seconds_until_expiry) = 0;
 
    virtual ccf::kv::ReadOnlyStorePtr get_store_at(
      RequestHandle handle, ccf::SeqNo seqno) = 0;
 
    virtual StatePtr get_state_at(
      RequestHandle handle,
      ccf::SeqNo seqno,
      ExpiryDuration seconds_until_expiry) = 0;
 
    virtual StatePtr get_state_at(RequestHandle handle, ccf::SeqNo seqno) = 0;
 
    virtual std::vector<ccf::kv::ReadOnlyStorePtr> get_store_range(
      RequestHandle handle,
      ccf::SeqNo start_seqno,
      ccf::SeqNo end_seqno,
      ExpiryDuration seconds_until_expiry) = 0;
 
    virtual std::vector<ccf::kv::ReadOnlyStorePtr> get_store_range(
      RequestHandle handle, ccf::SeqNo start_seqno, ccf::SeqNo end_seqno) = 0;
 
    virtual std::vector<StatePtr> get_state_range(
      RequestHandle handle,
      ccf::SeqNo start_seqno,
      ccf::SeqNo end_seqno,
      ExpiryDuration seconds_until_expiry) = 0;
 
    virtual std::vector<StatePtr> get_state_range(
      RequestHandle handle, ccf::SeqNo start_seqno, ccf::SeqNo end_seqno) = 0;
 
    virtual std::vector<ccf::kv::ReadOnlyStorePtr> get_stores_for(
      RequestHandle handle,
      const SeqNoCollection& seqnos,
      ExpiryDuration seconds_until_expiry) = 0;
    virtual std::vector<ccf::kv::ReadOnlyStorePtr> get_stores_for(
      RequestHandle handle, const SeqNoCollection& seqnos) = 0;
 
    virtual std::vector<StatePtr> get_states_for(
      RequestHandle handle,
      const SeqNoCollection& seqnos,
      ExpiryDuration seconds_until_expiry) = 0;
    virtual std::vector<StatePtr> get_states_for(
      RequestHandle handle, const SeqNoCollection& seqnos) = 0;
 
    virtual bool drop_cached_states(RequestHandle handle) = 0;
  };
}