Reads a Microsoft Access database (.mdb or .accdb) through ADO and the ACE OLE DB provider, read only and shared, so the file can stay open in Access. More...

#include <ace_backend.h>

Inheritance diagram for ACE_BACKEND:

Classes
struct	CYCLE_SESSION
	A session opened for one load cycle, and the tables it has read, which it never reads again. More...

struct	PASS_DIGEST
	What one complete pass over a table returned, as a verified read compares it. More...

Public Types
enum class	PROVIDER_STATE { AVAILABLE , MISSING , PENDING , BUSY }

Public Member Functions
	ACE_BACKEND (std::string aPath, std::string aPassword, int aTimeoutSeconds)

	~ACE_BACKEND () override

bool	Connect () override

void	Disconnect () override

bool	IsConnected () const override

bool	ListTables (std::vector< std::string > &aTables) override
	Lists the tables and views, sorted by name.

std::optional< DB_TABLE_INFO >	DescribeTable (const std::string &aTable) override

bool	ReadTable (const DB_TABLE_INFO &aTable, const std::vector< std::string > &aColumns, size_t aMaxRows, std::vector< std::string > &aLabels, const DB_ROW_SINK &aSink) override
	Reads rows of a table, handing each to aSink.

bool	ReadAllRows (const DB_TABLE_INFO &aTable, const std::vector< std::string > &aColumns, std::vector< std::string > &aLabels, const DB_ROW_SINK &aSink, const DB_RESTART_SINK &aRestart) override
	A verified read.

void	BeginLoadCycle (const DB_STOP_CHECK &aStopped) override
	Brackets a load cycle, in which the caller reads each table once.

void	EndLoadCycle () override
	Closes the sessions the cycle opened, on the worker thread.

std::string	GetLastError () const override

DB_FAILURE	GetLastFailure () const override

virtual bool	ListColumns (const std::string &aTable, std::vector< std::string > &aColumns)
	Lists the column names of a table as the catalog reports them, empty if it has none, false if the catalog failed.

virtual std::optional< bool >	ReadRow (const DB_TABLE_INFO &aTable, const std::vector< std::string > &aColumns, const std::string &aKeyColumn, const std::string &aKey, std::vector< std::string > &aLabels, std::vector< DB_VALUE > &aRow)
	Reads the one row whose key column equals aKey, using an indexed lookup if the backend has one.

Static Public Member Functions
static PROVIDER_STATE	ProviderState ()
	Tells whether the ACE OLE DB provider is installed and loads.

static std::string	ProviderPendingMessage ()
	The message for a source whose provider check has not finished.

static std::string	ProviderMissingMessage ()
	The message for a source that needs the provider when ProviderState() is MISSING.

static DB_BACKEND_RESULT	Create (const DATABASE_SOURCE &aSource, const wxString &aBasePath)
	Builds the backend for a source.

Static Public Attributes
static constexpr size_t	ALL_ROWS = std::numeric_limits<size_t>::max()
	Passed as ReadTable()'s row limit to read every row.

Private Member Functions
std::optional< PASS_DIGEST >	readPass (uint64_t aSession, const std::string &aSql, const std::string &aUnorderedSql, size_t aMaxRows, std::vector< std::string > &aLabels, const DB_ROW_SINK *aSink, std::optional< ACE_ENGINE_OP::CLOCK::time_point > aDeadline=std::nullopt)
	Runs one pass of aSql on aSession, recording a failure as the backend's.

std::optional< uint64_t >	freshSession (const std::string &aTable, ACE_ENGINE_OP::CLOCK::time_point aDeadline, const std::function< bool()> &aMayStart)
	A session of the cycle that has not read aTable, now marked as having read it, or nullopt if one could not open before aDeadline.

bool	closeSpentSessions (ACE_ENGINE_OP::CLOCK::time_point aDeadline)
	Closes the oldest sessions of the cycle, which have all read the current table, so that one more fits.

bool	cycleStopped () const

bool	pauseUnlessStopped (std::chrono::milliseconds aWait)
	Sleeps for aWait; false if the cycle's stop check came true first.

void	failStopped (const std::string &aTable)

bool	readVerified (const DB_TABLE_INFO &aTable, const std::vector< std::string > &aColumns, std::vector< std::string > &aLabels, const DB_ROW_SINK &aSink, const DB_RESTART_SINK &aRestart)
	The verified read itself, inside a load cycle.

template<typename R>
std::optional< R >	runOnWorker (std::function< R(DB_JOB_CONTEXT &)> aJob, const DB_ROW_SINK *aSink, std::shared_ptr< ACE_ENGINE_OP > aOp=nullptr, std::optional< std::chrono::milliseconds > aProgressBound=std::nullopt)
	Runs aJob on the worker, recording why it did not finish as the failure.

void	dropConnection (std::shared_ptr< ACE_ENGINE_OP > aOp=nullptr, bool aForExit=false)
	Forgets the connection and the cycle's sessions and closes them on the worker thread, never on the caller.

bool	closeOnWorker (std::vector< uint64_t > aIds, std::shared_ptr< ACE_ENGINE_OP > aOp, std::optional< std::chrono::milliseconds > aBound=std::nullopt)
	Closes aIds on the worker thread under aOp, recording a close that lost the engine lock; false if the wait for the worker, aBound or else what is left of aOp, expired.

void	fail (DB_FAILURE aFailure, std::string aError)

std::shared_ptr< ACE_ENGINE_OP >	newOp () const

void	failCall (DB_FAILURE aFailure, std::string aMessage)
	Records a failure of a call that ran, and drops the connection if the failure means it cannot be trusted.

bool	requireConnection ()
	Fails with a message and returns false unless a connection is open.

Private Attributes
std::string	m_path

std::string	m_password

int	m_timeout

std::shared_ptr< ACE_ENGINE_OP >	m_lastOp
	The operation the caller last ran, which a failure that drops the connection continues.

std::unique_ptr< DB_WORKER_THREAD >	m_worker

uint64_t	m_session = 0
	Names this backend's connection among those the worker thread holds.

std::wstring	m_progId
	The provider that opened the connection, which the cycle's sessions use too.

std::vector< CYCLE_SESSION >	m_cycleSessions

DB_STOP_CHECK	m_cycleStop
	Set by the outermost load cycle, which a verified read checks before every open and pass.

int	m_cycleDepth = 0
	How many load cycles are open; the sessions are closed when the last one ends.

std::atomic< bool >	m_connected { false }

std::string	m_lastError

DB_FAILURE	m_lastFailure = DB_FAILURE::UNKNOWN

Static Private Attributes
static constexpr size_t	MAX_CYCLE_SESSIONS = 2
	The most sessions a load cycle holds at once.

Detailed Description

Reads a Microsoft Access database (.mdb or .accdb) through ADO and the ACE OLE DB provider, read only and shared, so the file can stay open in Access.

Every COM object lives on the worker thread, an apartment of its own, so a file on a share that stopped answering costs the caller a bounded wait and not a hung program. The provider cannot cancel a read that is blocked on file I/O, so such a thread is detached and finishes when the operating system gives up on the share.

Definition at line 79 of file ace_backend.h.

Member Enumeration Documentation

◆ PROVIDER_STATE

enum class ACE_BACKEND::PROVIDER_STATE

strong

Enumerator
AVAILABLE
MISSING
PENDING	The check has not finished, so nothing is known yet.
BUSY	The check could not start because the engine lock stayed out of reach.

Definition at line 139 of file ace_backend.h.

Constructor & Destructor Documentation

◆ ACE_BACKEND()

ACE_BACKEND::ACE_BACKEND	(	std::string	aPath,
		std::string	aPassword,
		int	aTimeoutSeconds )

Parameters

aPath	the database file, as UTF-8
aPassword	the database password, empty if the file has none; never appears in a message or trace
aTimeoutSeconds	the provider's connection and command timeout, zero for its default; a call waits on the worker without progress for at most this plus 10 s, or 30 s when it is zero, and the provider probe of a first connect may add up to 10 s

Definition at line 1590 of file ace_backend.cpp.

References m_password, m_path, m_timeout, m_worker, MarkAccessWorkerAbandoned(), and move.

◆ ~ACE_BACKEND()

ACE_BACKEND::~ACE_BACKEND ( )

override

Definition at line 1606 of file ace_backend.cpp.

References dropConnection(), m_path, m_worker, newOp(), and traceDatabase.

Member Function Documentation

◆ BeginLoadCycle()

void ACE_BACKEND::BeginLoadCycle ( const DB_STOP_CHECK & aStopped )

overridevirtual

Brackets a load cycle, in which the caller reads each table once.

A backend may keep what it opens for the cycle's reads until the cycle ends. Cycles may nest, and only the outermost begin and end count. Nesting is backend-wide and may cross threads, as when a lookup on one thread reads a table while a refresh on another has a cycle open. The nested read keeps the stop check and sessions of the outermost cycle.

Parameters

aStopped may be empty; a backend that retries a read gives up when it returns true

Reimplemented from DATABASE_BACKEND.

Definition at line 2039 of file ace_backend.cpp.

References m_cycleDepth, and m_cycleStop.

Referenced by ReadAllRows().

◆ closeOnWorker()

bool ACE_BACKEND::closeOnWorker	(	std::vector< uint64_t >	aIds,
		std::shared_ptr< ACE_ENGINE_OP >	aOp,
		std::optional< std::chrono::milliseconds >	aBound = std::nullopt )

private

Closes aIds on the worker thread under aOp, recording a close that lost the engine lock; false if the wait for the worker, aBound or else what is left of aOp, expired.

Definition at line 1797 of file ace_backend.cpp.

References AccessEngineBusyMessage(), ACE_ENGINE_OP::EXPIRED, fail(), m_worker, and TIMEOUT.

Referenced by closeSpentSessions(), dropConnection(), and EndLoadCycle().

◆ closeSpentSessions()

bool ACE_BACKEND::closeSpentSessions ( ACE_ENGINE_OP::CLOCK::time_point aDeadline )

private

Closes the oldest sessions of the cycle, which have all read the current table, so that one more fits.

Definition at line 2107 of file ace_backend.cpp.

References DB_WORKER_THREAD::CallerBound(), closeOnWorker(), DescribeWorkerOutcome(), fail(), DB_WORKER_FAILURE::failure, m_connected, m_cycleSessions, m_lastError, m_path, m_session, m_timeout, m_worker, MAX_CYCLE_SESSIONS, and DB_WORKER_FAILURE::message.

Referenced by freshSession().

◆ Connect()

bool ACE_BACKEND::Connect ( )

overridevirtual

Implements DATABASE_BACKEND.

Definition at line 1819 of file ace_backend.cpp.

References _, AccessEngineBusyMessage(), AVAILABLE, BUSY, describeFailure(), fail(), FILE_NOT_FOUND, m_connected, m_lastError, m_lastFailure, m_password, m_path, m_progId, m_session, m_timeout, MISSING, newOp(), path, PENDING, PROVIDER_MISSING, ProviderMissingMessage(), ProviderPendingMessage(), result, runOnWorker(), TIMEOUT, UNKNOWN, and utf8().

◆ Create()

DB_BACKEND_RESULT DATABASE_BACKEND::Create	(	const DATABASE_SOURCE &	aSource,
		const wxString &	aBasePath )

staticinherited

Builds the backend for a source.

Parameters

aSource	the source as configured; ${CWD} is expanded in its connection string and path
aBasePath	the directory ${CWD} stands for

Returns: the backend, or a null backend with the failure and a message naming the problem

Definition at line 34 of file database_backend.cpp.

References _, ACCESS, DATABASE_SOURCE::Expanded(), INVALID, INVALID_TYPE, ACE_BACKEND::MISSING, NOT_SUPPORTED_ON_PLATFORM, ODBC, PROVIDER_MISSING, ACE_BACKEND::ProviderMissingMessage(), ACE_BACKEND::ProviderState(), source, SQLITE, UNKNOWN, and utf8().

Referenced by SCH_IO_DATABASE::connectOnce(), and SCH_IO_DATABASE::CreateConnection().

◆ cycleStopped()

bool ACE_BACKEND::cycleStopped ( ) const

private

Definition at line 2075 of file ace_backend.cpp.

References m_cycleStop.

Referenced by pauseUnlessStopped(), and readVerified().

◆ DescribeTable()

std::optional< DB_TABLE_INFO > ACE_BACKEND::DescribeTable ( const std::string & aTable )

overridevirtual

Returns: the table's columns in catalog order, or nullopt if it was not found or the catalog failed

Implements DATABASE_BACKEND.

Definition at line 1917 of file ace_backend.cpp.

References describeFailure(), failCall(), info, m_lastError, m_lastFailure, m_password, m_path, m_session, requireConnection(), result, runOnWorker(), and UNKNOWN.

◆ Disconnect()

void ACE_BACKEND::Disconnect ( )

overridevirtual

Implements DATABASE_BACKEND.

Definition at line 1879 of file ace_backend.cpp.

References dropConnection().

◆ dropConnection()

void ACE_BACKEND::dropConnection	(	std::shared_ptr< ACE_ENGINE_OP >	aOp = nullptr,
		bool	aForExit = false )

private

Forgets the connection and the cycle's sessions and closes them on the worker thread, never on the caller.

A live worker also learns the operation for its exit hook when aForExit is set, even with no connection to close. An abandoned or absent worker is left alone, since its sessions are not reachable from another thread.

Definition at line 1771 of file ace_backend.cpp.

References closeOnWorker(), m_connected, m_cycleSessions, m_session, m_worker, and newOp().

Referenced by Disconnect(), failCall(), runOnWorker(), and ~ACE_BACKEND().

◆ EndLoadCycle()

void ACE_BACKEND::EndLoadCycle ( )

overridevirtual

Closes the sessions the cycle opened, on the worker thread.

Reimplemented from DATABASE_BACKEND.

Definition at line 2047 of file ace_backend.cpp.

References closeOnWorker(), m_connected, m_cycleDepth, m_cycleSessions, m_cycleStop, m_session, and newOp().

Referenced by ReadAllRows().

◆ fail()

void ACE_BACKEND::fail	(	DB_FAILURE	aFailure,
		std::string	aError )

private

Definition at line 1651 of file ace_backend.cpp.

References m_lastError, m_lastFailure, m_password, ScrubSecret(), and traceDatabase.

Referenced by closeOnWorker(), closeSpentSessions(), Connect(), failCall(), failStopped(), readPass(), readVerified(), requireConnection(), and runOnWorker().

◆ failCall()

void ACE_BACKEND::failCall	(	DB_FAILURE	aFailure,
		std::string	aMessage )

private

Records a failure of a call that ran, and drops the connection if the failure means it cannot be trusted.

Definition at line 1706 of file ace_backend.cpp.

References dropConnection(), fail(), invalidates(), and m_lastOp.

Referenced by DescribeTable(), freshSession(), ListTables(), and readPass().

◆ failStopped()

void ACE_BACKEND::failStopped ( const std::string & aTable )

private

Definition at line 2081 of file ace_backend.cpp.

References _, fail(), UNKNOWN, and utf8().

Referenced by readVerified().

◆ freshSession()

std::optional< uint64_t > ACE_BACKEND::freshSession	(	const std::string &	aTable,
		ACE_ENGINE_OP::CLOCK::time_point	aDeadline,
		const std::function< bool()> &	aMayStart )

private

A session of the cycle that has not read aTable, now marked as having read it, or nullopt if one could not open before aDeadline.

An open the file's lock refuses is tried again after a growing pause. No open starts unless aMayStart, which records its own failure, allows it.

Definition at line 2144 of file ace_backend.cpp.

References DB_WORKER_THREAD::CallerBound(), closeSpentSessions(), describeFailure(), failCall(), FILE_IN_USE, FileInUseBackoff(), m_cycleSessions, m_password, m_path, m_progId, m_timeout, path, pauseUnlessStopped(), result, runOnWorker(), and traceDatabase.

Referenced by readVerified().

◆ GetLastError()

std::string ACE_BACKEND::GetLastError ( ) const

inlineoverridevirtual

Implements DATABASE_BACKEND.

Definition at line 135 of file ace_backend.h.

References m_lastError.

◆ GetLastFailure()

DB_FAILURE ACE_BACKEND::GetLastFailure ( ) const

inlineoverridevirtual

Implements DATABASE_BACKEND.

Definition at line 137 of file ace_backend.h.

References m_lastFailure.

◆ IsConnected()

bool ACE_BACKEND::IsConnected ( ) const

inlineoverridevirtual

Implements DATABASE_BACKEND.

Definition at line 97 of file ace_backend.h.

References m_connected.

◆ ListColumns()

bool DATABASE_BACKEND::ListColumns	(	const std::string &	aTable,
		std::vector< std::string > &	aColumns )

virtualinherited

Lists the column names of a table as the catalog reports them, empty if it has none, false if the catalog failed.

Reimplemented in ODBC_BACKEND.

Definition at line 71 of file database_backend.cpp.

References DescribeTable(), GetLastError(), info, and DB_COLUMN::name.

◆ ListTables()

bool ACE_BACKEND::ListTables ( std::vector< std::string > & aTables )

overridevirtual

Lists the tables and views, sorted by name.

Implements DATABASE_BACKEND.

Definition at line 1885 of file ace_backend.cpp.

References describeFailure(), failCall(), m_lastError, m_password, m_path, m_session, requireConnection(), result, and runOnWorker().

◆ newOp()

std::shared_ptr< ACE_ENGINE_OP > ACE_BACKEND::newOp ( ) const

private

Returns: a fresh operation whose deadline is one caller bound from now

Definition at line 1600 of file ace_backend.cpp.

References DB_WORKER_THREAD::CallerBound(), and m_timeout.

Referenced by Connect(), dropConnection(), EndLoadCycle(), runOnWorker(), and ~ACE_BACKEND().

◆ pauseUnlessStopped()

bool ACE_BACKEND::pauseUnlessStopped ( std::chrono::milliseconds aWait )

private

Sleeps for aWait; false if the cycle's stop check came true first.

Definition at line 2088 of file ace_backend.cpp.

References cycleStopped(), and left.

Referenced by freshSession(), and readVerified().

◆ ProviderMissingMessage()

std::string ACE_BACKEND::ProviderMissingMessage ( )

static

The message for a source that needs the provider when ProviderState() is MISSING.

Definition at line 1637 of file ace_backend.cpp.

References _, message, and utf8().

Referenced by Connect(), DATABASE_BACKEND::Create(), and describeFailure().

◆ ProviderPendingMessage()

std::string ACE_BACKEND::ProviderPendingMessage ( )

static

The message for a source whose provider check has not finished.

Definition at line 1631 of file ace_backend.cpp.

References _, and utf8().

Referenced by Connect().

◆ ProviderState()

ACE_BACKEND::PROVIDER_STATE ACE_BACKEND::ProviderState ( )

static

Tells whether the ACE OLE DB provider is installed and loads.

The check runs on first use, on a COM thread of its own, and a finished answer is kept for the life of the process. This does not wait, so a check still running reports PENDING and Connect() is the one place that waits for it. Nothing calls this at startup.

Definition at line 1623 of file ace_backend.cpp.

Referenced by accessProvider(), and DATABASE_BACKEND::Create().

◆ ReadAllRows()

bool ACE_BACKEND::ReadAllRows	(	const DB_TABLE_INFO &	aTable,
		const std::vector< std::string > &	aColumns,
		std::vector< std::string > &	aLabels,
		const DB_ROW_SINK &	aSink,
		const DB_RESTART_SINK &	aRestart )

overridevirtual

A verified read.

Every pass runs on a session of the load cycle that has not read the table, since a session keeps serving the pages it read for seconds after another user changed them; a session is opened when none is left, and the cycle keeps at most two. The first pass only hashes the rows. Every later pass streams its rows to aSink and hashes them, and is compared with the pass before it. A pass that disagrees is followed by aRestart and another pass after a pause of 50 to 250 ms. The first two passes always run. No retry starts once the caller's bound, counted from the end of the second pass, has passed, and no open or pass starts once the cycle's stop check is true; the read then fails, as FILE_IN_USE if the bound ran out, and delivers nothing that may be kept. A read outside a load cycle runs in a cycle of its own.

A running open or pass is bounded only by the worker's progress bound, so a live read of a slow share is never cut short. Its wait for the engine lock ends a bound after it started, or for a retry when the bound runs out.

A table is published only when two consecutive complete passes, on two sessions that had not read the table before, returned identical content (row count, column names and an ordered hash over every column). The published table then equals the table's state at one instant between the passes, provided that (a) no row returns to an earlier value between the passes, (b) no single writer commit takes longer than a pass to become fully visible, and (c) neither session serves a page older than the other pass's read of it. This detects disagreement; it does not certify transactional consistency. There is no cross-table consistency.

Reimplemented from DATABASE_BACKEND.

Definition at line 2202 of file ace_backend.cpp.

References BeginLoadCycle(), EndLoadCycle(), m_lastError, m_lastFailure, readVerified(), and requireConnection().

◆ readPass()

std::optional< ACE_BACKEND::PASS_DIGEST > ACE_BACKEND::readPass	(	uint64_t	aSession,
		const std::string &	aSql,
		const std::string &	aUnorderedSql,
		size_t	aMaxRows,
		std::vector< std::string > &	aLabels,
		const DB_ROW_SINK *	aSink,
		std::optional< ACE_ENGINE_OP::CLOCK::time_point >	aDeadline = std::nullopt )

private

Runs one pass of aSql on aSession, recording a failure as the backend's.

Parameters

aSink	receives the rows; null only hashes them
aDeadline	is a verified read's deadline for the engine lock, which leaves the pass bounded by progress

Returns: the pass's digest, or nullopt if it failed

Definition at line 1992 of file ace_backend.cpp.

References DB_WORKER_THREAD::CallerBound(), describeFailure(), fail(), failCall(), DB_READ_DELIVERY::Finish(), DB_READ_DELIVERY::Labels(), m_password, m_path, m_timeout, result, runOnWorker(), DB_READ_DELIVERY::Sink(), DB_READ_DELIVERY::SinkFailureMessage(), DB_READ_DELIVERY::SinkThrew(), and UNKNOWN.

Referenced by ReadTable(), and readVerified().

◆ ReadRow()

virtual std::optional< bool > DATABASE_BACKEND::ReadRow	(	const DB_TABLE_INFO &	aTable,
		const std::vector< std::string > &	aColumns,
		const std::string &	aKeyColumn,
		const std::string &	aKey,
		std::vector< std::string > &	aLabels,
		std::vector< DB_VALUE > &	aRow )

inlinevirtualinherited

Reads the one row whose key column equals aKey, using an indexed lookup if the backend has one.

Returns: nullopt if the backend has no indexed lookup, otherwise true when aRow was filled

Reimplemented in ODBC_BACKEND.

Definition at line 170 of file database_backend.h.

◆ ReadTable()

bool ACE_BACKEND::ReadTable	(	const DB_TABLE_INFO &	aTable,
		const std::vector< std::string > &	aColumns,
		size_t	aMaxRows,
		std::vector< std::string > &	aLabels,
		const DB_ROW_SINK &	aSink )

overridevirtual

Reads rows of a table, handing each to aSink.

Parameters

aColumns	the columns to read; empty reads all of them
aMaxRows	stops after this many rows; zero fills aLabels and fetches no rows. A bounded read is ordered by the first column where the backend can.
aLabels	is filled with the result-column labels as the source spells them, before the first call to aSink

Returns: false on failure, in which case the caller discards any rows already delivered

Implements DATABASE_BACKEND.

Definition at line 1956 of file ace_backend.cpp.

References DATABASE_BACKEND::ALL_ROWS, m_lastError, m_session, DB_TABLE_INFO::name, readPass(), requireConnection(), and top().

◆ readVerified()

bool ACE_BACKEND::readVerified	(	const DB_TABLE_INFO &	aTable,
		const std::vector< std::string > &	aColumns,
		std::vector< std::string > &	aLabels,
		const DB_ROW_SINK &	aSink,
		const DB_RESTART_SINK &	aRestart )

private

The verified read itself, inside a load cycle.

Definition at line 2233 of file ace_backend.cpp.

References _, DATABASE_BACKEND::ALL_ROWS, DB_WORKER_THREAD::CallerBound(), cycleStopped(), fail(), failStopped(), FILE_IN_USE, freshSession(), m_path, m_timeout, MS, DB_TABLE_INFO::name, path, pauseUnlessStopped(), readPass(), table, traceDatabase, and utf8().

Referenced by ReadAllRows().

◆ requireConnection()

bool ACE_BACKEND::requireConnection ( )

private

Fails with a message and returns false unless a connection is open.

Definition at line 1715 of file ace_backend.cpp.

References _, fail(), m_connected, UNKNOWN, and utf8().

Referenced by DescribeTable(), ListTables(), ReadAllRows(), and ReadTable().

◆ runOnWorker()

template<typename R>

std::optional< R > ACE_BACKEND::runOnWorker	(	std::function< R(DB_JOB_CONTEXT &)>	aJob,
		const DB_ROW_SINK *	aSink,
		std::shared_ptr< ACE_ENGINE_OP >	aOp = nullptr,
		std::optional< std::chrono::milliseconds >	aProgressBound = std::nullopt )

private

Runs aJob on the worker, recording why it did not finish as the failure.

Definition at line 1726 of file ace_backend.cpp.

References AccessEngineBusyMessage(), DB_WORKER_FAILURE::connection, DescribeWorkerOutcome(), DB_WORKER_FAILURE::DROP, dropConnection(), fail(), DB_WORKER_FAILURE::failure, DB_WORKER_FAILURE::FORGET, m_connected, m_cycleSessions, m_lastOp, m_path, m_session, m_worker, DB_WORKER_FAILURE::message, newOp(), result, and TIMEOUT.

Referenced by Connect(), DescribeTable(), freshSession(), ListTables(), and readPass().

Member Data Documentation

◆ ALL_ROWS

size_t DATABASE_BACKEND::ALL_ROWS = std::numeric_limits<size_t>::max()

staticconstexprinherited

Passed as ReadTable()'s row limit to read every row.

Definition at line 106 of file database_backend.h.

Referenced by ReadAllRows(), ACE_BACKEND::ReadTable(), ODBC_BACKEND::ReadTable(), SQLITE_BACKEND::ReadTable(), and ACE_BACKEND::readVerified().

◆ m_connected

std::atomic<bool> ACE_BACKEND::m_connected { false }

private

Definition at line 266 of file ace_backend.h.

Referenced by closeSpentSessions(), Connect(), dropConnection(), EndLoadCycle(), IsConnected(), requireConnection(), and runOnWorker().

◆ m_cycleDepth

int ACE_BACKEND::m_cycleDepth = 0

private

How many load cycles are open; the sessions are closed when the last one ends.

Definition at line 264 of file ace_backend.h.

Referenced by BeginLoadCycle(), and EndLoadCycle().

◆ m_cycleSessions

std::vector<CYCLE_SESSION> ACE_BACKEND::m_cycleSessions

private

Definition at line 258 of file ace_backend.h.

Referenced by closeSpentSessions(), dropConnection(), EndLoadCycle(), freshSession(), and runOnWorker().

◆ m_cycleStop

DB_STOP_CHECK ACE_BACKEND::m_cycleStop

private

Set by the outermost load cycle, which a verified read checks before every open and pass.

Definition at line 261 of file ace_backend.h.

Referenced by BeginLoadCycle(), cycleStopped(), and EndLoadCycle().

◆ m_lastError

std::string ACE_BACKEND::m_lastError

private

Definition at line 268 of file ace_backend.h.

Referenced by closeSpentSessions(), Connect(), DescribeTable(), fail(), GetLastError(), ListTables(), ReadAllRows(), and ReadTable().

◆ m_lastFailure

DB_FAILURE ACE_BACKEND::m_lastFailure = DB_FAILURE::UNKNOWN

private

Definition at line 269 of file ace_backend.h.

Referenced by Connect(), DescribeTable(), fail(), GetLastFailure(), and ReadAllRows().

◆ m_lastOp

std::shared_ptr<ACE_ENGINE_OP> ACE_BACKEND::m_lastOp

private

The operation the caller last ran, which a failure that drops the connection continues.

Definition at line 245 of file ace_backend.h.

Referenced by failCall(), and runOnWorker().

◆ m_password

std::string ACE_BACKEND::m_password

private

Definition at line 241 of file ace_backend.h.

Referenced by ACE_BACKEND(), Connect(), DescribeTable(), fail(), freshSession(), ListTables(), and readPass().

◆ m_path

std::string ACE_BACKEND::m_path

private

Definition at line 240 of file ace_backend.h.

Referenced by ACE_BACKEND(), closeSpentSessions(), Connect(), DescribeTable(), freshSession(), ListTables(), readPass(), readVerified(), runOnWorker(), and ~ACE_BACKEND().

◆ m_progId

std::wstring ACE_BACKEND::m_progId

private

The provider that opened the connection, which the cycle's sessions use too.

Definition at line 253 of file ace_backend.h.

Referenced by Connect(), and freshSession().

◆ m_session

uint64_t ACE_BACKEND::m_session = 0

private

Names this backend's connection among those the worker thread holds.

Definition at line 250 of file ace_backend.h.

Referenced by closeSpentSessions(), Connect(), DescribeTable(), dropConnection(), EndLoadCycle(), ListTables(), ReadTable(), and runOnWorker().

◆ m_timeout

int ACE_BACKEND::m_timeout

private

Definition at line 242 of file ace_backend.h.

Referenced by ACE_BACKEND(), closeSpentSessions(), Connect(), freshSession(), newOp(), readPass(), and readVerified().

◆ m_worker

std::unique_ptr<DB_WORKER_THREAD> ACE_BACKEND::m_worker

private

Definition at line 247 of file ace_backend.h.

Referenced by ACE_BACKEND(), closeOnWorker(), closeSpentSessions(), dropConnection(), runOnWorker(), and ~ACE_BACKEND().

◆ MAX_CYCLE_SESSIONS

size_t ACE_BACKEND::MAX_CYCLE_SESSIONS = 2

staticconstexprprivate

The most sessions a load cycle holds at once.

Definition at line 256 of file ace_backend.h.

Referenced by closeSpentSessions().

The documentation for this class was generated from the following files:

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Member Enumeration Documentation

◆ PROVIDER_STATE

Constructor & Destructor Documentation

◆ ACE_BACKEND()

◆ ~ACE_BACKEND()

Member Function Documentation

◆ BeginLoadCycle()

◆ closeOnWorker()

◆ closeSpentSessions()

◆ Connect()

◆ Create()

◆ cycleStopped()

◆ DescribeTable()

◆ Disconnect()

◆ dropConnection()

◆ EndLoadCycle()

◆ fail()

◆ failCall()

◆ failStopped()

◆ freshSession()

◆ GetLastError()

◆ GetLastFailure()

◆ IsConnected()

◆ ListColumns()

◆ ListTables()

◆ newOp()

◆ pauseUnlessStopped()

◆ ProviderMissingMessage()

◆ ProviderPendingMessage()

◆ ProviderState()

◆ ReadAllRows()

◆ readPass()

◆ ReadRow()

◆ ReadTable()

◆ readVerified()

◆ requireConnection()

◆ runOnWorker()

Member Data Documentation

◆ ALL_ROWS

◆ m_connected

◆ m_cycleDepth

◆ m_cycleSessions

◆ m_cycleStop

◆ m_lastError

◆ m_lastFailure

◆ m_lastOp

◆ m_password

◆ m_path

◆ m_progId

◆ m_session

◆ m_timeout

◆ m_worker

◆ MAX_CYCLE_SESSIONS