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audacity/src/DBConnection.h
Paul Licameli a3fcd611b5
Dependency cleanup (#627)
* DBConnection doesn't use ProjectFileIO or need friendship...

... Instead, it is given its own weak_ptr to the project

* Demote the bypass flag into DBConnection...

... So SqliteSampleBlock needs ProjectFileIO only to get the DBConnection

* Accessor functions for the connection objects for SqliteSampleBlock

* Another level of indirection to get to the DBConnection object...

... The document holds the unique_ptr to DBConnection in an attached object;
later we want the SqliteSampleBlockFactory to locate the same pointer without
using ProjectFileIO

* SqliteSampleBlock and its factory don't use class ProjectFileIO...

... Instead they share a pointer to the pointer to the current DBConnection.

This means they no longer know how to invoke the lazy opening of that
connection.

So just require that this be done before any operations on blocks happen.  If
it hasn't, throw and let the application recover.

* ProjectFileIO no longer needs weak_ptr to Project for safety...

... so eliminate much ugliness from 127696879dcc5ca687ec50a4ccef7acbed563926

* Move DBConnection to new files...

... And SqliteSampleBlock does not depend on ProjectFileIO.

* SampleBlock.h doesn't need ClientData.h

* Function ProjectFileIO::Conn() isn't needed
2020-07-23 01:04:46 -05:00

107 lines
2.6 KiB
C++

/**********************************************************************
Audacity: A Digital Audio Editor
DBConection.h
Paul Licameli -- split from ProjectFileIO.h
**********************************************************************/
#ifndef __AUDACITY_DB_CONNECTION__
#define __AUDACITY_DB_CONNECTION__
#include <atomic>
#include <condition_variable>
#include <map>
#include <memory>
#include <mutex>
#include <thread>
#include "ClientData.h"
struct sqlite3;
struct sqlite3_stmt;
class wxString;
class AudacityProject;
class DBConnection
{
public:
explicit
DBConnection(const std::weak_ptr<AudacityProject> &pProject);
~DBConnection();
bool Open(const char *fileName);
bool Close();
bool SafeMode(const char *schema = "main");
bool FastMode(const char *schema = "main");
bool Assign(sqlite3 *handle);
sqlite3 *Detach();
sqlite3 *DB();
int GetLastRC() const ;
const wxString GetLastMessage() const;
enum StatementID
{
GetSamples,
GetSummary256,
GetSummary64k,
LoadSampleBlock,
InsertSampleBlock,
DeleteSampleBlock
};
sqlite3_stmt *GetStatement(enum StatementID id);
sqlite3_stmt *Prepare(enum StatementID id, const char *sql);
void SetBypass( bool bypass );
bool ShouldBypass();
private:
bool ModeConfig(sqlite3 *db, const char *schema, const char *config);
void CheckpointThread();
static int CheckpointHook(void *data, sqlite3 *db, const char *schema, int pages);
private:
std::weak_ptr<AudacityProject> mpProject;
sqlite3 *mDB;
std::thread mCheckpointThread;
std::condition_variable mCheckpointCondition;
std::mutex mCheckpointMutex;
std::atomic_bool mCheckpointStop{ false };
std::atomic_int mCheckpointWaitingPages{ 0 };
std::atomic_int mCheckpointCurrentPages{ 0 };
std::map<enum StatementID, sqlite3_stmt *> mStatements;
// Bypass transactions if database will be deleted after close
bool mBypass;
};
using Connection = std::unique_ptr<DBConnection>;
// This object attached to the project simply holds the pointer to the
// project's current database connection, which is initialized on demand,
// and may be redirected, temporarily or permanently, to another connection
// when backing the project up or saving or saving-as.
class ConnectionPtr final
: public ClientData::Base
, public std::enable_shared_from_this< ConnectionPtr >
{
public:
static ConnectionPtr &Get( AudacityProject &project );
static const ConnectionPtr &Get( const AudacityProject &project );
~ConnectionPtr() override;
Connection mpConnection;
};
#endif