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CQueryExec Class Reference

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Query execution environment holds the function registry and the execution context. More...

#include <util/qparse/query_exec.hpp>

+ Inheritance diagram for CQueryExec:
+ Collaboration diagram for CQueryExec:

Public Types

typedef unsigned int TFieldID
- Public Types inherited from CObject
enum  EAllocFillMode { eAllocFillNone = 1 , eAllocFillZero , eAllocFillPattern }
 Control filling of newly allocated memory. More...
typedef CObjectCounterLocker TLockerType
 Default locker type for CRef. More...
typedef atomic< Uint8TCounter
 Counter type is CAtomiCounter. More...
typedef Uint8 TCount
 Alias for value type of counter. More...

Public Member Functions

 CQueryExec ()
virtual ~CQueryExec ()
void AddFunc (CQueryParseNode::EType func_type, CQueryFunctionBase *func)
 Register function implementation. More...
void AddImplicitSearchFunc (CQueryFunctionBase *func)
 This is a callback for implicit search nodes Our syntax allows queries like (a=1) AND "search_term" Execution recognises "search_term" connected with logical operation represents a special case. More...
CQueryFunctionBaseGetImplicitSearchFunc ()
CQueryFunctionBaseGetFunc (CQueryParseNode::EType func_type)
 Return query function pointer (if registered). More...
virtual void CallFunction (const string &name, CQueryParseTree::TNode &node)
 Extend this function to look up and invoke functions that appear in the query. More...
virtual void Evaluate (CQueryParseTree &qtree)
 Run query tree evaluation. More...
virtual void Evaluate (CQueryParseTree &qtree, CQueryParseTree::TNode &node)
virtual bool ResolveIdentifier (const std::string &, bool &)
 If query has an identifier, this will resolve it in an application-specific way. More...
virtual bool ResolveIdentifier (const std::string &, Int8 &)
virtual bool ResolveIdentifier (const std::string &, double &)
virtual bool ResolveIdentifier (const std::string &, std::string &)
virtual bool ResolveIdentifier (const TFieldID &, bool &)
virtual bool ResolveIdentifier (const TFieldID &, Int8 &)
virtual bool ResolveIdentifier (const TFieldID &, double &)
virtual bool ResolveIdentifier (const TFieldID &, std::string &)
virtual bool HasIdentifier (const std::string &)
virtual TFieldID GetIdentifier (const std::string &)
virtual CQueryParseNode::EType IdentifierType (const std::string &)
 Some applications may know the type of an identifier. More...
virtual void EvalStart ()
virtual bool EvalNext (CQueryParseTree &)
 Move to (iterate) to next entry. More...
virtual bool EvalComplete ()
int GetQueriedCount () const
int GetExceptionCount () const
- Public Member Functions inherited from CObject
 CObject (void)
 Constructor. More...
 CObject (const CObject &src)
 Copy constructor. More...
virtual ~CObject (void)
 Destructor. More...
CObjectoperator= (const CObject &src) THROWS_NONE
 Assignment operator. More...
bool CanBeDeleted (void) const THROWS_NONE
 Check if object can be deleted. More...
bool IsAllocatedInPool (void) const THROWS_NONE
 Check if object is allocated in memory pool (not system heap) More...
bool Referenced (void) const THROWS_NONE
 Check if object is referenced. More...
bool ReferencedOnlyOnce (void) const THROWS_NONE
 Check if object is referenced only once. More...
void AddReference (void) const
 Add reference to object. More...
void RemoveReference (void) const
 Remove reference to object. More...
void ReleaseReference (void) const
 Remove reference without deleting object. More...
virtual void DoNotDeleteThisObject (void)
 Mark this object as not allocated in heap – do not delete this object. More...
virtual void DoDeleteThisObject (void)
 Mark this object as allocated in heap – object can be deleted. More...
void * operator new (size_t size)
 Define new operator for memory allocation. More...
void * operator new[] (size_t size)
 Define new[] operator for 'array' memory allocation. More...
void operator delete (void *ptr)
 Define delete operator for memory deallocation. More...
void operator delete[] (void *ptr)
 Define delete[] operator for memory deallocation. More...
void * operator new (size_t size, void *place)
 Define new operator. More...
void operator delete (void *ptr, void *place)
 Define delete operator. More...
void * operator new (size_t size, CObjectMemoryPool *place)
 Define new operator using memory pool. More...
void operator delete (void *ptr, CObjectMemoryPool *place)
 Define delete operator. More...
virtual void DebugDump (CDebugDumpContext ddc, unsigned int depth) const
 Define method for dumping debug information. More...
- Public Member Functions inherited from CDebugDumpable
 CDebugDumpable (void)
virtual ~CDebugDumpable (void)
void DebugDumpText (ostream &out, const string &bundle, unsigned int depth) const
void DebugDumpFormat (CDebugDumpFormatter &ddf, const string &bundle, unsigned int depth) const
void DumpToConsole (void) const

Protected Types

typedef vector< CQueryFunctionBase * > TFuncReg

Protected Member Functions

CQueryParseTreeGetQTree ()
- Protected Member Functions inherited from CObject
virtual void DeleteThis (void)
 Virtual method "deleting" this object. More...

Protected Attributes

TFuncReg m_FuncReg
unique_ptr< CQueryFunctionBasem_ImplicitSearchFunc
int m_ExceptionCount
int m_QueriedCount

Private Member Functions

 CQueryExec (const CQueryExec &)
CQueryExecoperator= (const CQueryExec &)


class CQueryFunctionBase

Additional Inherited Members

- Static Public Member Functions inherited from CObject
static NCBI_XNCBI_EXPORT void ThrowNullPointerException (void)
 Define method to throw null pointer exception. More...
static NCBI_XNCBI_EXPORT void ThrowNullPointerException (const type_info &type)
static EAllocFillMode GetAllocFillMode (void)
static void SetAllocFillMode (EAllocFillMode mode)
static void SetAllocFillMode (const string &value)
 Set mode from configuration parameter value. More...
- Static Public Member Functions inherited from CDebugDumpable
static void EnableDebugDump (bool on)
- Static Public Attributes inherited from CObject
static const TCount eCounterBitsCanBeDeleted = 1 << 0
 Define possible object states. More...
static const TCount eCounterBitsInPlainHeap = 1 << 1
 Heap signature was found. More...
static const TCount eCounterBitsPlaceMask
 Mask for 'in heap' state flags. More...
static const int eCounterStep = 1 << 2
 Skip over the "in heap" bits. More...
static const TCount eCounterValid = TCount(1) << (sizeof(TCount) * 8 - 2)
 Minimal value for valid objects (reference counter is zero) Must be a single bit value. More...
static const TCount eCounterStateMask
 Valid object, and object in heap. More...

Detailed Description

Query execution environment holds the function registry and the execution context.

Execution context is vaguely defined term, it can be anything query functions need: open files, databases, network connections, pools of threads, etc.

Query execution consists of distinct several phases:
1.Construction of execution environment
   All function implementations are registered in CQueryExec
2.Query parsing (see CQueryParseTree). This step transforms query (string)
  into query tree, the tree reflects operations precedence
3.Parsing tree validation and transformation (optional)
4.Query execution-evaluation. Execution engine traverses the query tree calling
  appropriate functions to do expression(query tree node) evaluation.
  Execution results for every tree node are stored in the tree as user
  objects (classes derived from IQueryParseUserObject).

Definition at line 143 of file query_exec.hpp.

The documentation for this class was generated from the following files:
Modified on Tue Apr 23 07:37:32 2024 by rev. 669887