Writable_Journal.h

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#ifndef joedb_Writable_Journal_declared
#define joedb_Writable_Journal_declared
 
#include "joedb/Writable.h"
#include "joedb/journal/Readonly_Journal.h"
#include "joedb/journal/Async_Writer.h"
 
namespace joedb
{
 /// @ingroup journal
 class Writable_Journal: public Readonly_Journal, public Writable
 {
  private:
   void generic_update
   (
    Table_Id table_id,
    Record_Id record_id,
    Field_Id field_id,
    operation_t operation
   );
 
  public:
   explicit Writable_Journal(Journal_Construction_Lock &lock);
 
   explicit Writable_Journal(Journal_Construction_Lock &&lock):
    Writable_Journal(lock)
   {
   }
 
   explicit Writable_Journal(Buffered_File &file):
    Writable_Journal(Journal_Construction_Lock(file))
   {
   }
 
   void append()
   {
    file.set_position(checkpoint_position);
   }
 
   int64_t pull_from(const Readonly_Journal &journal, int64_t until);
   int64_t pull_from(const Readonly_Journal &journal)
   {
    return pull_from(journal, journal.get_checkpoint());
   }
 
   int64_t ahead_of_checkpoint() const noexcept;
 
   void flush() final {file.flush();}
 
   int64_t get_position() const override {return file.get_position();}
   void start_writing(int64_t position) override;
   void soft_checkpoint_at(int64_t position) override;
   void hard_checkpoint_at(int64_t position) override;
 
   void create_table(const std::string &name) final;
   void drop_table(Table_Id table_id) final;
 
   void rename_table
   (
    Table_Id table_id,
    const std::string &name
   ) final;
 
   void add_field
   (
    Table_Id table_id,
    const std::string &name,
    Type type
   ) final;
 
   void drop_field
   (
    Table_Id table_id,
    Field_Id field_id
   ) final;
 
   void rename_field
   (
    Table_Id table_id,
    Field_Id field_id,
    const std::string &name
   ) final;
 
   void custom(const std::string &name) final;
   void comment(const std::string &comment) final;
   void timestamp(int64_t timestamp) final;
   void valid_data() final;
 
   void insert_into(Table_Id table_id, Record_Id record_id) final;
   void delete_from(Table_Id table_id, Record_Id record_id) final;
 
   void insert_vector
   (
    Table_Id table_id,
    Record_Id record_id,
    size_t size
   ) final;
 
   void delete_vector
   (
    Table_Id table_id,
    Record_Id record_id,
    size_t size
   ) final;
 
   #define TYPE_MACRO(type, return_type, type_id, read_method, write_method)\
   void update_##type_id\
   (\
    Table_Id table_id,\
    Record_Id record_id,\
    Field_Id field_id,\
    return_type value\
   ) final;\
   void update_vector_##type_id\
   (\
    Table_Id table_id,\
    Record_Id record_id,\
    Field_Id field_id,\
    size_t size,\
    const type *value\
   ) final;
   #include "joedb/TYPE_MACRO.h"
 
   bool wants_blob_data() const final {return true;}
   Blob write_blob(const std::string &data) final;
 
   Async_Writer get_async_tail_writer()
   {
    return Async_Writer(file, get_checkpoint());
   }
 
   void lock_pull();
   bool is_locked() const {return file.tail_is_locked();}
   void unlock() noexcept;
 
   ~Writable_Journal() override;
 };
 
 class Journal_Lock
 {
  private:
   Writable_Journal &journal;
 
  public:
   Journal_Lock(Writable_Journal &journal): journal(journal)
   {
    if (journal.get_position() > journal.get_checkpoint())
     throw Exception("locking journal with uncheckpointed data");
    journal.lock_pull();
   }
 
   Journal_Lock(const Journal_Lock &lock) = delete;
   Journal_Lock &operator=(const Journal_Lock &lock) = delete;
 
   ~Journal_Lock()
   {
    journal.unlock();
   }
 };
}
 
#endif