DbiResult Class Reference

Concept Abstract base class representing the Result of a single database query. If query suceeded the Result will hold (own) a vector of table row objects that correspond to result of the query. It will also own a DbiValidityRec that gives the range over which the result is valid. Purpose To provide suitable objects to cache. DbiResults can be checked to see if they satisfy new queries. More...

#include <DbiResult.h>

Inheritance diagram for DbiResult:

List of all members.

Public Member Functions
	DbiResult (DbiResultSet *resultSet=0, const DbiValidityRec *vrec=0, const string &sqlQualifiers="")
virtual	~DbiResult ()
virtual Bool_t	CanReuse () const
virtual Bool_t	CanSave () const
virtual void	Connect () const
virtual DbiResultKey *	CreateKey () const =0
virtual void	Disconnect () const
const DbiExceptionLog &	GetExceptionLog () const
Int_t	GetID () const
virtual const DbiResultKey *	GetKey () const
virtual UInt_t	GetNumAggregates () const =0
virtual UInt_t	GetNumClients () const
virtual UInt_t	GetNumRows () const =0
const string &	GetSqlQualifiers () const
virtual const DbiTableRow *	GetTableRow (UInt_t rowNum) const =0
virtual const DbiTableRow *	GetTableRowByIndex (UInt_t index) const
virtual const DbiValidityRec &	GetValidityRec (const DbiTableRow *=0) const
virtual const DbiValidityRec &	GetValidityRecGlobal () const
Bool_t	IsExtendedContext () const
virtual Bool_t	Owns (const DbiTableRow *) const
Bool_t	ResultsFromDb () const
virtual const string &	TableName () const
void	CaptureExceptionLog (UInt_t startFrom)
virtual Bool_t	CanDelete (const DbiResult *res=0)
	Return true if no clients and unlikely to be reused.
virtual Bool_t	Satisfies (const VldContext &vc, const Dbi::Task &task)
virtual Bool_t	Satisfies (const string &)
virtual Bool_t	Satisfies (const DbiValidityRec &, const string &="")
virtual void	DeRegisterKey ()
	Key handling.
virtual void	RegisterKey ()
virtual void	Streamer (DbiBinaryFile &file)
virtual void	SetCanReuse (Bool_t reuse)
Protected Member Functions
void	SetResultsFromDb ()
void	BuildLookUpTable () const
Bool_t	LookUpBuilt () const
virtual void	SetTableName (const string &tableName)
virtual void	SetValidityRec (const DbiValidityRec &vRec)
Private Attributes
Int_t	fID
	Unique ID within the current job.
Bool_t	fCanReuse
DbiValidityRec	fEffVRec
IndexToRow_t	fIndexKeys
const DbiResultKey *	fKey
Bool_t	fResultsFromDb
	True is at least part didn't come from cache.
Int_t	fNumClients
string	fTableName
string	fSqlQualifiers
DbiExceptionLog	fExceptionLog
	Exception log produced when query was executed.
Static Private Attributes
Int_t	fgLastID
	Used to allocate unique ID within the current job.

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Detailed Description

Concept Abstract base class representing the Result of a single database query. If query suceeded the Result will hold (own) a vector of table row objects that correspond to result of the query. It will also own a DbiValidityRec that gives the range over which the result is valid. Purpose To provide suitable objects to cache. DbiResults can be checked to see if they satisfy new queries.

Id

DbiResult.h,v 1.22 2006/08/08 10:51:32 west Exp

DatabaseInterface

Contact: n.west1@physics.ox.ac.uk

Definition at line 48 of file DbiResult.h.

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Constructor & Destructor Documentation

DbiResult::DbiResult (  DbiResultSet *  resultSet = 0, const DbiValidityRec *  vrec = 0, const string &  sqlQualifiers = "" )

Definition at line 51 of file DbiResult.cxx. References fEffVRec, fTableName, LEA_CTOR, MSG, and DbiRowStream::TableNameTc(). : fID(++fgLastID), fCanReuse(kTRUE), fEffVRec(0), fKey(0), fResultsFromDb(kFALSE), fNumClients(0), fTableName("Unknown"), fSqlQualifiers(sqlQualifiers) { // // // Purpose: Default constructor // // Arguments: // resultSet in Pointer DbiResultSet from query. May be null. // vrec in Pointer to validity record from query. // May be null // sqlQualifier in Extended Context sql qualifiers // // Return: n/a // // Contact: N. West // // Specification:- // ============= // // o Create Result from DbiResultSet generated by query. // Program Notes:- // ============= // None. LEA_CTOR //Leak Checker MSG("Dbi", Msg::kVerbose) << "Creating DbiResult" << endl; if ( vrec ) fEffVRec = *vrec; if ( resultSet ) fTableName = resultSet->TableNameTc(); }

DbiResult::~DbiResult (   )  [virtual]

Definition at line 99 of file DbiResult.cxx. References DeRegisterKey(), fNumClients, LEA_DTOR, and MSG. { // // // Purpose: Destructor // // Arguments: // None. // // Return: n/a // // Contact: N. West // // Specification:- // ============= // // o Destroy Result. // Program Notes:- // ============= // None. LEA_DTOR //Leak Checker MSG("Dbi", Msg::kVerbose) << "Destroying DbiResult." << endl; if ( fNumClients ) MSG("Dbi", Msg::kWarning) << "Warning: Destroying DbiResult with " << fNumClients << " clients " << endl; this->DeRegisterKey(); }

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Member Function Documentation

void DbiResult::BuildLookUpTable (   )  const [protected]

Definition at line 135 of file DbiResult.cxx. References fIndexKeys, DbiTableRow::GetAggregateNo(), DbiTableRow::GetIndex(), GetNumRows(), DbiTableRow::GetOwner(), DbiValidityRec::GetSeqNo(), GetTableRow(), GetTableRowByIndex(), GetValidityRec(), IsExtendedContext(), MAXMSG, MSG, and TableName(). Referenced by DbiResultNonAgg::GetTableRowByIndex(), and DbiResultNonAgg::Streamer(). { // // // Purpose: Build look-up Natural Index -> TableRow. // // Contact: N. West // // Program Notes:- // ============= // // This member function assumes that the sub-class can support // the GetTableRow(...) and GetNumRows methods so take care if // called in the sub-class ctor. // Extended Context serach can produce duplicates. Bool_t duplicatesOK = this->IsExtendedContext(); MSG("Dbi", Msg::kVerbose) << "Building look-uptable. Allow duplicates: " << duplicatesOK << endl; for ( Int_t rowNo = this->GetNumRows()-1; rowNo >= 0; --rowNo ) { const DbiTableRow* row = this->GetTableRow(rowNo); UInt_t index = row->GetIndex(rowNo); // Ensure we use this class's GetTableRowByIndex, the method is // virtual but if the subclass has called this method then it must // be the right one to use. [Actually DbiResultAgg overrides // GetTableRowByIndex, but only to make building lazy]. const DbiTableRow* row2 = this->DbiResult::GetTableRowByIndex(index); MSG("Dbi", Msg::kVerbose) << "Look-up. Row no " << rowNo << " index " << index << " row,row2 " << (void*) row << "," << (void*) row2 << endl; if ( row2 != 0 && row2 != row && ! duplicatesOK ) { std::ostringstream msg; msg << "Duplicated row natural index: " << index << " Found at row " << rowNo << " of table " << this->TableName() << ":-\n index of agg " << row->GetAggregateNo(); if ( row->GetOwner() ) msg << "(SEQNO " << row->GetOwner()->GetValidityRec(row).GetSeqNo() << ")"; msg << " matches agg " << row2->GetAggregateNo(); if ( row2->GetOwner() ) msg << "(SEQNO " << row2->GetOwner()->GetValidityRec(row2).GetSeqNo() << ")"; MAXMSG("Dbi",Msg::kError,20) << msg.str() << endl; } else fIndexKeys[index] = row; } }

Bool_t DbiResult::CanDelete (  const DbiResult *  res = 0  )  [virtual]

Return true if no clients and unlikely to be reused. Definition at line 190 of file DbiResult.cxx. References CanReuse(), GetNumClients(), GetValidityRec(), DbiValidityRec::HasExpired(), and SetCanReuse(). Referenced by DbiCache::Purge(). { // // // Purpose: See if suitable for deleting. // // Arguments: // res in A DbiResult that is currently used. // Optional: default = 0. // If the query would be satisfied apart from the date, then // assume we have moved out of the validity window, never // to return! if ( res && this->CanReuse() && this->GetValidityRec().HasExpired(res->GetValidityRec()) ) this->SetCanReuse(kFALSE); return ! this->GetNumClients() && ! this->CanReuse(); }

virtual Bool_t DbiResult::CanReuse (   )  const [inline, virtual]

Definition at line 61 of file DbiResult.h. Referenced by CanDelete(), DbiResultNonAgg::Satisfies(), DbiResultAgg::Satisfies(), and Satisfies(). { return fCanReuse; }

virtual Bool_t DbiResult::CanSave (   )  const [inline, virtual]

Definition at line 62 of file DbiResult.h. Referenced by DbiTableProxy::SaveToL2Cache(). { return kTRUE; }

void DbiResult::CaptureExceptionLog (  UInt_t  startFrom  )

Definition at line 213 of file DbiResult.cxx. References DbiExceptionLog::Clear(), DbiExceptionLog::Copy(), fExceptionLog, and DbiExceptionLog::GetGELog(). Referenced by DbiTableProxy::Query(). { // // // Purpose: Capture Exception Log from latest entries in Global Exception Log. fExceptionLog.Clear(); DbiExceptionLog::GetGELog().Copy(fExceptionLog,startFrom); }

virtual void DbiResult::Connect (   )  const [inline, virtual]

Definition at line 63 of file DbiResult.h. Referenced by DbiResultAgg::DbiResultAgg(), DbiResultPtr< T >::DbiResultPtr(), and DbiResultPtr< T >::NewQuery(). { ++fNumClients; }

virtual DbiResultKey* DbiResult::CreateKey (   )  const [pure virtual]

Implemented in DbiResultAgg, and DbiResultNonAgg. Referenced by DbiResultAgg::CreateKey(), and RegisterKey().

void DbiResult::DeRegisterKey (   )  [virtual]

Key handling. Definition at line 225 of file DbiResult.cxx. References DbiRecord::DeleteKey(), fKey, DbiServices::GetRecord(), and MSG. Referenced by ~DbiResult(). { // // // Purpose: Deregister key if it exists. if ( ! fKey ) return; DbiRecord* record = DbiServices::GetRecord(); if ( ! record ) { MSG("Dbi",Msg::kWarning) << "Attempting to deregister DbiResultKey at " << (void*) fKey << " but owning DbiRecord cannot be found." << endl; } else { record->DeleteKey(fKey); fKey = 0; } }

virtual void DbiResult::Disconnect (   )  const [inline, virtual]

Definition at line 65 of file DbiResult.h. Referenced by DbiResultPtr< T >::Disconnect(). { --fNumClients; }

const DbiExceptionLog& DbiResult::GetExceptionLog (   )  const [inline]

Definition at line 66 of file DbiResult.h. { return fExceptionLog; }

Int_t DbiResult::GetID (   )  const [inline]

Definition at line 67 of file DbiResult.h. Referenced by DbiResultPtr< T >::GetResultID(). { return fID; }

const DbiResultKey * DbiResult::GetKey (   )  const [virtual]

Definition at line 245 of file DbiResult.cxx. References fKey, and DbiResultKey::GetEmptyKey(). Referenced by DbiCache::Adopt(), and DbiResultPtr< T >::GetKey(). { // Purpose: Get the associated DbiResultKey, or an empty one if none exists. return fKey ? fKey : DbiResultKey::GetEmptyKey(); }

virtual UInt_t DbiResult::GetNumAggregates (   )  const [pure virtual]

Implemented in DbiResultAgg, and DbiResultNonAgg. Referenced by DbiCache::Search().

virtual UInt_t DbiResult::GetNumClients (   )  const [inline, virtual]

Definition at line 70 of file DbiResult.h. Referenced by CanDelete(), DbiCache::Purge(), and Satisfies(). { return fNumClients; }

virtual UInt_t DbiResult::GetNumRows (   )  const [pure virtual]

Implemented in DbiResultAgg, and DbiResultNonAgg. Referenced by BuildLookUpTable(), DbiResultAgg::DbiResultAgg(), DbiValRecSet::GetNumRows(), DbiResultPtr< T >::GetNumRows(), DbiResultPtr< T >::NewQuery(), DbiResultPtr< T >::NextQuery(), RegisterKey(), DbiTableProxy::SaveToL2Cache(), and DbiCache::Search().

const string& DbiResult::GetSqlQualifiers (   )  const [inline]

Definition at line 73 of file DbiResult.h. Referenced by DbiResultNonAgg::Satisfies(), and DbiResultAgg::Satisfies(). { return fSqlQualifiers; }

virtual const DbiTableRow* DbiResult::GetTableRow (  UInt_t  rowNum  )  const [pure virtual]

Implemented in DbiResultAgg, and DbiResultNonAgg. Referenced by BuildLookUpTable(), DbiResultAgg::DbiResultAgg(), DbiResultPtr< T >::GetRow(), and DbiValRecSet::GetTableRow().

const DbiTableRow * DbiResult::GetTableRowByIndex (  UInt_t  index  )  const [virtual]

Reimplemented in DbiResultNonAgg. Definition at line 255 of file DbiResult.cxx. References fIndexKeys. Referenced by BuildLookUpTable(), DbiResultPtr< T >::GetRowByIndex(), and DbiResultNonAgg::GetTableRowByIndex(). { // // // Purpose: Return row corresponding to Natural Index (or 0 if none) // // Contact: N. West // // Use Find rather than operator[] to avoid creating entry // if index missing IndexToRow_t::const_iterator idx = fIndexKeys.find(index); return ( idx == fIndexKeys.end() ) ? 0 : (*idx).second; }

virtual const DbiValidityRec& DbiResult::GetValidityRec (  const DbiTableRow *  = 0  )  const [inline, virtual]

Reimplemented in DbiResultAgg. Definition at line 76 of file DbiResult.h. Referenced by DbiCache::Adopt(), BuildLookUpTable(), CanDelete(), DbiResultNonAgg::CreateKey(), DbiResultAgg::CreateKey(), DbiResultPtr< T >::GetValidityRec(), DbiResultPtr< T >::NewQuery(), DbiResultPtr< T >::NextQuery(), DbiCache::Purge(), DbiTableProxy::RestoreFromL2Cache(), DbiResultNonAgg::Satisfies(), and Satisfies(). { return GetValidityRecGlobal(); }

virtual const DbiValidityRec& DbiResult::GetValidityRecGlobal (   )  const [inline, virtual]

Definition at line 79 of file DbiResult.h. Referenced by DbiCache::Adopt(), DbiResultAgg::GetValidityRec(), and DbiResultAgg::Streamer(). { return fEffVRec; }

Bool_t DbiResult::IsExtendedContext (   )  const [inline]

Definition at line 81 of file DbiResult.h. Referenced by BuildLookUpTable(), and Satisfies(). { return this->GetSqlQualifiers() != ""; }

Bool_t DbiResult::LookUpBuilt (   )  const [inline, protected]

Definition at line 116 of file DbiResult.h. Referenced by DbiResultNonAgg::GetTableRowByIndex(). { return fIndexKeys.size() > 0; }

virtual Bool_t DbiResult::Owns (  const DbiTableRow *   )  const [inline, virtual]

Reimplemented in DbiResultNonAgg. Definition at line 83 of file DbiResult.h. { return kFALSE; }

void DbiResult::RegisterKey (   )  [virtual]

Definition at line 272 of file DbiResult.cxx. References DbiRecord::AdoptKey(), CreateKey(), fKey, GetNumRows(), DbiServices::GetRecord(), and MSG. Referenced by DbiCache::Adopt(). { // // // Purpose: Create and register key if set not empty and not already done. if ( fKey || this->GetNumRows() == 0) return; DbiRecord* record = DbiServices::GetRecord(); if ( ! record ) { MSG("Dbi",Msg::kWarning) << "cannot create and register key" << ", owning DbiRecord cannot be found." << endl; } else { DbiResultKey* key = this->CreateKey(); record->AdoptKey(key); fKey = key; } }

Bool_t DbiResult::ResultsFromDb (   )  const [inline]

Definition at line 84 of file DbiResult.h. Referenced by DbiResultPtr< T >::ResultsFromDb(), and DbiTableProxy::SaveToL2Cache(). { return fResultsFromDb; }

virtual Bool_t DbiResult::Satisfies (  const DbiValidityRec &  , const string &  = "" )  [inline, virtual]

Reimplemented in DbiResultNonAgg. Definition at line 100 of file DbiResult.h. {return kFALSE;}

virtual Bool_t DbiResult::Satisfies (  const string &   )  [inline, virtual]

Not all DbiResult classes can satisfy these types of query so those that do must override. Reimplemented in DbiResultAgg. Definition at line 99 of file DbiResult.h. {return kFALSE;}

Bool_t DbiResult::Satisfies (  const VldContext &  vc, const Dbi::Task &  task )  [virtual]

All DbiResult classes can satisfy this type of primary query so impliment here. Definition at line 293 of file DbiResult.cxx. References CanReuse(), GetNumClients(), GetValidityRec(), DbiValidityRec::HasExpired(), DbiValidityRec::IsCompatible(), IsExtendedContext(), MSG, and SetCanReuse(). Referenced by DbiCache::Search(). { // // // Purpose: Check to see if this Result satisfies specific context query. // // Arguments: // vc in Context of query // task in Task of query // // Return: kTRUE if can satisfy query. // // Contact: N. West // // Program Notes:- // ============= // If it cannot satisfy the query in a way that suggests // that its unlikely that it will satisfy future queries // then mark as cannot reuse so that it becomes eligible // for purging. // Extended Context queries cannot satisfy specific context queries. Bool_t isExtendedContext = this->IsExtendedContext(); Bool_t canReuse = this->CanReuse(); Bool_t isCompatible = this->GetValidityRec().IsCompatible(vc,task); Bool_t hasExpired = this->GetValidityRec().HasExpired(vc,task); UInt_t numClients = this->GetNumClients(); MSG("Dbi",Msg::kDebug) << " Checking result with DbiValidityRec:- \n " << this->GetValidityRec() << " With extended context: " << isExtendedContext << " CanReuse: " << canReuse << " Is Compatible: " << isCompatible << " HasExpired: " << hasExpired << " number of clients: " << numClients << endl; if ( isExtendedContext ) return kFALSE; if ( canReuse && isCompatible ) return kTRUE; // If the query would be satisfied apart from the date, then // assume we have moved out of the validity window, never // to return! if ( canReuse && hasExpired && numClients == 0 ) { MSG("Dbi",Msg::kDebug) << " Marking result as not reusable" << endl; this-> SetCanReuse(kFALSE); } return kFALSE; }

virtual void DbiResult::SetCanReuse (  Bool_t  reuse  )  [inline, virtual]

Definition at line 108 of file DbiResult.h. Referenced by CanDelete(), DbiResultAgg::DbiResultAgg(), DbiTableProxy::Query(), Satisfies(), and DbiCache::SetStale(). { fCanReuse = reuse ; }

void DbiResult::SetResultsFromDb (   )  [inline, protected]

Definition at line 111 of file DbiResult.h. { fResultsFromDb = kTRUE; }

virtual void DbiResult::SetTableName (  const string &  tableName  )  [inline, protected, virtual]

Definition at line 120 of file DbiResult.h. { fTableName = tableName; }

virtual void DbiResult::SetValidityRec (  const DbiValidityRec &  vRec  )  [inline, protected, virtual]

Definition at line 122 of file DbiResult.h. { fEffVRec = vRec; }

void DbiResult::Streamer (  DbiBinaryFile &  file  )  [virtual]

Reimplemented in DbiResultAgg, and DbiResultNonAgg. Definition at line 349 of file DbiResult.cxx. References fEffVRec, fNumClients, fResultsFromDb, fTableName, DbiBinaryFile::IsReading(), DbiBinaryFile::IsWriting(), MSG, and DbiValidityRec::Streamer(). Referenced by operator<<(), operator>>(), and DbiResultNonAgg::Streamer(). { // // // Purpose: I/O to binary file // // Program Notes:- // ============= // Don't store fIndexKeys; it will be rebuilt on input by the subclass. if ( file.IsReading() ) { MSG("Dbi", Msg::kDebug) << " Restoring DbiResult ..." << endl; file >> fCanReuse; fEffVRec.Streamer(file); MSG("Dbi", Msg::kVerbose) << " Restored " << fEffVRec << endl; fResultsFromDb = kFALSE; fNumClients = 0; file >> fTableName; MSG("Dbi", Msg::kVerbose) << " Restored string " << fTableName << endl; } else if ( file.IsWriting() ) { MSG("Dbi", Msg::kDebug) << " Saving DbiResult ..." << endl; file << fCanReuse; MSG("Dbi", Msg::kVerbose) << " Saving " << fEffVRec << endl; fEffVRec.Streamer(file); MSG("Dbi", Msg::kVerbose) << " Saving string " << fTableName << endl; file << fTableName; } }

virtual const string& DbiResult::TableName (   )  const [inline, virtual]

Definition at line 85 of file DbiResult.h. Referenced by DbiCache::Adopt(), BuildLookUpTable(), DbiValRecSet::GetTableName(), and DbiCache::Purge(). { return fTableName; }

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Member Data Documentation

Bool_t DbiResult::fCanReuse [private]

Definition at line 134 of file DbiResult.h.

DbiValidityRec DbiResult::fEffVRec [private]

Definition at line 137 of file DbiResult.h. Referenced by DbiResult(), and Streamer().

DbiExceptionLog DbiResult::fExceptionLog [private]

Exception log produced when query was executed. Definition at line 158 of file DbiResult.h. Referenced by CaptureExceptionLog().

Int_t DbiResult::fgLastID [static, private]

Used to allocate unique ID within the current job.

Int_t DbiResult::fID [private]

Unique ID within the current job. Definition at line 131 of file DbiResult.h.

IndexToRow_t DbiResult::fIndexKeys [mutable, private]

Definition at line 140 of file DbiResult.h. Referenced by BuildLookUpTable(), and GetTableRowByIndex().

const DbiResultKey* DbiResult::fKey [private]

Definition at line 143 of file DbiResult.h. Referenced by DeRegisterKey(), GetKey(), and RegisterKey().

Int_t DbiResult::fNumClients [mutable, private]

Definition at line 148 of file DbiResult.h. Referenced by Streamer(), and ~DbiResult().

Bool_t DbiResult::fResultsFromDb [private]

True is at least part didn't come from cache. Definition at line 146 of file DbiResult.h. Referenced by Streamer().

string DbiResult::fSqlQualifiers [private]

Null unless Extended Context query in which case it contains:- context-sql;data-sql;fill-options Definition at line 155 of file DbiResult.h.

string DbiResult::fTableName [private]

Definition at line 151 of file DbiResult.h. Referenced by DbiResult(), and Streamer().

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

• DbiResult.h
• DbiResult.cxx

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