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| == EPICS: C++ class definitions for Database Definition ==
| | This page is obsolete. It is replaced by dbdInterfaces. |
| | |
| May 12 2005
| |
| | |
| <b>UNDER CONSTRUCTION - DO NOT COMMENT</b>
| |
| <center>
| |
| | |
| == Overview ==
| |
| | |
| </center>
| |
| | |
| This document describes the C++ class definitions for code that implements
| |
| the semantics for records created from Database Definitions. The definitions
| |
| are intented by code that includes header files generated from dbd definitions
| |
| and also by code that does not include the header files.
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| Header files are generated from the following dbd definitions:
| |
| * <tt>record</tt>
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| * <tt>struct</tt>
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| * <tt>menu</tt>
| |
| | |
| | |
| ----
| |
| <center>
| |
| | |
| == dbdTypes.h ==
| |
| | |
| </center>
| |
| | |
| File dbdTypes.h describes the datatypes used by V4 databases:
| |
| The following naming conventions are used:
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| ; dbf
| |
| : and name starting with dbf describes a struct or record field. For example dbfString describes a field(name,string).
| |
| ; *Dbf*
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| : A class name that has Dbd imbeded in it describes something directly related to a dbd statement. For example LinkDbdSupport describes a dbd link definition.
| |
| | |
| <tt>dbdTypes.h</tt> contains the following:
| |
| | |
| namespace Dbd {
| |
| /* TBD dbdNdimArrayT*/
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| enum dbfType {
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| dbfUnknownT,dbfBooleanT,dbfOctetT,
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| dbfInt16T,dbfUInt16T,dbfInt32T,dbfUInt32T,dbfInt64T,dbfUInt64T,
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| dbfFloat32T,dbfFloat64T,
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| dbfStringT,
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| dbfStructT,
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| dbfMenuT,dbfEnumT,
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| dbfLinkT,dbfDeviceT,
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| dbfArrayT
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| };
| |
| | |
| /* some of the following may require OSD definitions*/
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| typedef bool dbfBoolean;
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| typedef char dbfOctet;
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| typedef short dbfInt16;
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| typedef unsigned short dbfUInt16;
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| typedef int dbfInt32;
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| typedef unsigned int dbfUInt32;
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| typedef long long dbfInt64;
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| typedef unsigned long long dbfUInt64;
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| typedef float dbfFloat32;
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| typedef double dbfFloat64;
| |
| | |
| /*dbfString holds UTF-8 characters*/
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| class dbfString {
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| public:
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| dbfInt32 capacity; /*capacity in bytes*/
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| dbfOctet *pstorage;
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| };
| |
| | |
| // FieldDbdPtr is the address of a dbfType
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| typedef void *FieldDbdPtr;
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| // StructDbdPtr references a class generated from a struct dbd
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| typedef void * StructDbdPtr;
| |
| | |
| // InterfacePtr references a class that contains only methods
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| typedef void *InterfacePtr;
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| class Interface {
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| public:
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| dbfString name;
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| InterfacePtr interface;
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| };
| |
| | |
| // The following Interfaces are described below
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| class StructDbdLifetime;
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| class LinkDbdSupport;
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| | |
| class StructDbdMember {
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| public:
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| dbfString name;
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| dbfType type;
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| };
| |
| | |
| class StructDbd{
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| public:
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| dbfString name;
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| dbfInt16 nmembers;
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| Interface *plifetime; // references a StructDbdLifetime
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| StructDbdMember *pmember[]; // ptr to array of ptr to StructDbdMember
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| };
| |
| | |
| class dbfStruct{
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| public:
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| StructDbd *pstructDef;
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| StructDbdPtr ptr;
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| };
| |
| | |
| class MenuDbfDef{
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| public:
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| dbfString name;
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| dbfInt16 nchoices;
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| dbfString *pchoice[];
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| };
| |
| | |
| class dbfMenu{
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| public:
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| dbfInt16 index;
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| MenuDbfDef *pmenuDef;
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| };
| |
| | |
| class dbfEnum{
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| public:
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| dbfInt16 index;
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| dbfInt16 nchoices;
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| dbfString *pchoice[];
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| };
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|
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| enum LinkDir {
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| LinkDirNone,
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| LinkDirForward,
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| LinkDirIn,
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| LinkDirOut,
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| LinkDirInOut
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| };
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| class LinkDbd{ //describes dbd link statement
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| public:
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| LinkDir dir;
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| dbfString choiceName;
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| dbfString dataStructName;
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| InterfacePtr *pinterface;
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| };
| |
| | |
| class dbfLink{
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| public:
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| LinkDir dir;
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| dbfString choiceName;
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| LinkDbd *plinkDef; //LinkDbd will reference a LinkDbdSupport
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| dbfStruct dataStruct;
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| };
| |
| | |
| class DeviceDbd { //describes dbd device statement
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| public:
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| LinkDir dir;
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| dbfString interfaceName;
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| dbfString choiceName;
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| dbfString dataStructName;
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| InterfacePtr *pinterface;
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| };
| |
| | |
| class dbfDevice{
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| public:
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| LinkDir dir;
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| dbfString choiceName;
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| DeviceDbd *pdeviceDef;
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| dbfStruct dataStruct;
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| };
| |
| | |
| template< class ARR_T > class dbfArray {
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| public:
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| dbfInt32 capacity; /*capacity in number of elements*/
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| dbfInt32 size; /*current number of elements*/
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| dbfType type;
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| ARR_T *pstorage;
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| };
| |
| | |
| /* The following array types are supported by dbdCore
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| * dbfArray<void>;
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| * dbfArray<dbfOctet>;
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| * dbfArray<dbfInt16>;
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| * dbfArray<dbfUInt16>;
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| * dbfArray<dbfInt32>;
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| * dbfArray<dbfUInt32>;
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| * dbfArray<dbfInt64>;
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| * dbfArray<dbfUInt64>;
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| * dbfArray<dbfFloat32>;
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| * dbfArray<dbfFloat64>;
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| * dbfArray<dbfString>;
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| * dbfArray<dbfLinkField>;
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| **/
| |
| | |
| // The following describes record types and record instances
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| class UserDbdField;
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| class userFieldHandler {
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| public:
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| virtual bool initialize(dbfString *errorMessage,
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| iocRecord *precord,UserDbdField *puserField) = 0;
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| virtual bool finalize(dbfString *errorMessage,
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| iocRecord *precord,UserDbdField *puserField) = 0;
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| virtual bool process(dbfString *errorMessage,
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| iocRecord *precord,UserDbdField *puserField) = 0;
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| };
| |
| | |
| class UserDbdField {
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| public:
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| dbfString name;
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| dbfType type;
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| FieldDbdPtr pfield;
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| InterfacePtr *pinterface; // references userFieldHandler
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| }
| |
| | |
| class RecordDbdField {
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| public:
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| dbfString name;
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| dbfType type;
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| };
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|
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| class RecordDbd { // describes a record type
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| dbfArray< UserDbdField > userField;
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| dbfArray< RecordDbdField > recField;
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| Interface *plifetime; // references a StructDbdLifetime
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| }
| |
| | |
| // every struct and every record support module implements the following
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| // The implementation is generated from the dbd definition
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| class StructDbdLifetime {
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| public:
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| virtual StructDbdPtr create() = 0;
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| virtual bool initialize(dbfString *errorMessage,
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| StructDbdPtr ptr) = 0;
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| virtual bool finalize(dbfString *errorMessage,
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| StructDbdPtr ptr) = 0;
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| virtual void destroy(StructDbdPtr ptr) = 0;
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| virtual void *indexToAddr(dbfString *errorMessage,
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| StructDbdPtr ptr, dbfInt16 index) = 0;
| |
| // ???? is anything else needed
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| };
| |
| | |
| // every link support module implements the following interface
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| class LinkDbdSupport {
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| public:
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| virtual void report(dbfString *errorMessage,
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| iocRecord *precord, dbfLink *pdbfLink) = 0;
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| virtual bool initialize(dbfString *errorMessage,
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| iocRecord *precord, dbfLink *pdbfLink) = 0;
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| virtual bool finalize(dbfString *errorMessage,
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| iocRecord *precord, dbfLink *pdbfLink) = 0;
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| virtual bool connect(dbfString *errorMessage,
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| iocRecord *precord, dbfLink *pdbfLink) = 0;
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| virtual bool disconnect(dbfString *errorMessage,
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| iocRecord *precord, dbfLink *pdbfLink) = 0;
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| virtual bool get(dbfString *errorMessage,
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| iocRecord *precord, dbfLink *pdbfLink,
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| dbfType type, FieldDbdPtr pfield) = 0;
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| virtual bool put(dbfString *errorMessage,
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| iocRecord *precord, dbfLink *pdbfLink,
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| dbfType type, FieldDbdPtr pfield) = 0;
| |
| };
| |
| | |
| /* record support implements the following*/
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| class RecordDbdSupport {
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| public:
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| virtual iocRecord *create(dbfString *errorMessage) = 0;
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| virtual bool destroy(dbfString *errorMessage, iocRecord *precord) = 0;
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| virtual bool init(dbfString *errorMessage,
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| iocRecord *precord, bool firstPass) = 0;
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| virtual void special(iocRecord *precord, iocRecord *precord,
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| bool after,
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| dbfInt16 nlevels, // number of elements in fieldIndex
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| dbfInt16 fieldIndex[] // array of field indices
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| ) = 0;
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| };
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| }; // namespace Dbd
| |
| | |
| ----
| |
| <center>
| |
| | |
| == Discussion of dbfTypes ==
| |
| | |
| </center>
| |
| | |
| === Primitive Types ===
| |
| The types dbfBoolean, dbfOctet, dbfInt16, dbfUInt16, dbfInt32, dbfUInt32, dbfInt64, dbfUInt64, dbfFloat32, dbfFloat64 all map to a C primitive type. Currently the C type is defined in <tt>iocTypes.h</tt>. It may be necessary to provide operating system dependent definitions for some of the types. For example on some architectures a dbfInt64 may have to be defined as a C <tt>long</tt> rather than a <tt>long long</tt>.
| |
| | |
| If a record is defined as:
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| record(xxx) extends iocRecord {
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| ...
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| field(fbool,bool)
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| field(foctet,octet)
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| ...
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| field(ffloat64,float64)
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| ...
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| }
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| Then the generated header file will be
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| class xxxRecord : iocRecord {
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| public:
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| dbfBoolean fbool;
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| dbfOctet foctet;
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| ...
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| dbfFloat64 ffloat64;
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| ...
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| };
| |
| | |
| <tt>dbfType dbfTypeUnknownT</tt> is reserved for unknown types and will normally be cause by some configuration error.
| |
| === dbfString ===
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| <tt>dbfString</tt> is described as:
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| class dbfString {
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| public:
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| dbfInt32 capacity; /*capacity in bytes*/
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| dbfOctet *pstorage;
| |
| };
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| If a record definition contains
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| field(sfield,string)
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| Then the generated header file contains
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| dbfString sfield;
| |
| | |
| <tt>pstorage</tt>will always be the address of a UTF-8 null terminated character string. The <tt>capacity</tt> is the the number of bytes referenced by <tt>pstorage</tt> <bold>NOT</bold> the number of characters.
| |
| | |
| === dbfStruct ===
| |
| | |
| <dbfStruct></tt> is described as:
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| class dbfStruct{
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| public:
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| StructDbd *pstructDef;
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| StructDbdPtr ptr;
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| };
| |
| | |
| If a record definition contains
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| field(sstruct,struct(name))
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| Then the generated header file contains
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| dbfStruct sfield;
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| <tt>dbfStruct:ptr</tt> is the address of storage for the structure and <tt>pstructDef</tt> is the address of a description of the structure. The members of <tt>StructDbd</tt> are:
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| ; <tt>name</tt>
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| : The name of the struct.
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| ; <tt>nmembers</tt>
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| : The number of members, e.g. fields in the structure.
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| ; <tt>plifetime</tt>
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| : The address of an implementation of interface <tt>StructDbdLifetime</tt>. The implementation is automatically generated from the dbd <tt>struct</tt> statement. See below for a description of the <tt>StructDbdLifetime</tt> methods.
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| ; <tt>pmember</tt>
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| : pointer to an array of pointers to <tt>StructDbdMember</tt>. Each StructDbdMember contains the name and type of the member.
| |
| | |
| Note that given a dbfStruct it is possible to locate both the address and description of the associated structure.
| |
| | |
| | |
| | |
| === dbfMenu ===
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| <dbfMenu></tt> is described as:
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| class dbfMenu{
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| public:
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| dbfInt16 index;
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| MenuDbfDef *pmenuDef;
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| };
| |
| | |
| If a record definition contains
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| field(fmenu,menu(name))
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| Then the generated header file contains
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| dbfMenu fmenu;
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| The definition of dbfMenu provides the current menu index and also the menu definition.
| |
| | |
| === dbfEnum ===
| |
| <dbfEnum></tt> is described as:
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| class dbfEnum{
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| public:
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| dbfInt16 index;
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| dbfInt16 nchoices;
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| dbfString *pchoice[];
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| };
| |
| | |
| If a record definition contains
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| field(fenum,enum)
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| Then the generated header file contains
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| dbfEnum fenum;
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| The definition of dbfEnum provides the current enum index as well as a description on all the choices associated with the enum.
| |
| | |
| === dbfLink ===
| |
| <tt>dbfLink</tt> is described as
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| class dbfLink{
| |
| public:
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| LinkDir dir;
| |
| dbfString choiceName;
| |
| LinkDbd *plinkDef; //LinkDbd will reference a LinkDbdSupport
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| dbfStruct dataStruct;
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| };
| |
| If a record definition contains
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| field(flink,link(in))
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| Then the generated header file contains
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| dbfLink flink;
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| The members of dbfLink are initialized by locating a dbd <tt>link</tt> definition that matches the <tt>dir</tt> specified in the dbd <tt>field</tt> definition.
| |
| | |
| Each dbd <tt>link</tt> definition has an asociated C description:
| |
| class LinkDbd{ //describes dbd link statement
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| public:
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| LinkDir dir;
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| dbfString choiceName;
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| dbfString dataStructName;
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| InterfacePtr *pinterface;
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| };
| |
| | |
| The members of <tt>dbfLink</tt> are initialized as follows:
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| ; <tt>dir</tt>
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| : This is taken from either the <tt>field</tt> definition or from the <tt>LinkDbd</tt> definition and is the most restrictive. For example if one says inout and the other says in then <tt>dir</tt> will be in.
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| ; <tt>choiceName</tt>
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| : The record instance specifies this and it is used to locate the associated dbd <tt>link</tt> definition.
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| ; <tt>plinkDef</tt>
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| : This is the address of the <tt>LinkDbd</tt>.
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| ; <tt>dataStruct</tt>
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| : The describes the data structure specified in the dbd <tt>link</tt> definition. It contains data used by the link support.
| |
| | |
| Note that link support always implements interface <tt>LinkDbdSupport</tt>
| |
| === dbfDevice ===
| |
| | |
| A <tt>dbfDevice</tt> is similar to a <tt>dbfLink</tt> except that the interface implemented by the device support is also specified, i.e. instead of implementing interface <tt>LinkDbdSupport</tt>, the device support implements an interface that both record support and device support understand.
| |
| | |
| | |
| === dbfArray ===
| |
| | |
| Discussion needed. Note that multi-dimensional arrays must also be described.
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|
| |
| | |
| ----
| |
| <center>
| |
| | |
| == Discussion of Standard Interfaces ==
| |
| | |
| </center>
| |
| === <tt>StructDbdLifetime</tt> ===
| |
| Every dbd <tt>struct</tt> and <tt>record</tt> has an associated <tt>StructDbdLifetime</tt> interface implementation. A tool is provided that automatically generates the implementation form the dbd definition.
| |
| <tt>StructDbdLifetime</tt> is described as:
| |
| class StructDbdLifetime {
| |
| public:
| |
| virtual StructDbdPtr create() = 0;
| |
| virtual bool initialize(dbfString *errorMessage,
| |
| StructDbdPtr ptr) = 0;
| |
| virtual bool finalize(dbfString *errorMessage,
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| StructDbdPtr ptr) = 0;
| |
| virtual void destroy(StructDbdPtr ptr) = 0;
| |
| virtual void *indexToAddr(dbfString *errorMessage,
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| StructDbdPtr ptr, dbfInt16 index) = 0;
| |
| // ???? is anything else needed
| |
| };
| |
| where:
| |
| ; <tt>create</tt>
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| : Creates storage for the struct or record.
| |
| ; <tt>initialize</tt>
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| : initializes the struct or record
| |
| ; <tt>finalize<tt>
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| : cleans up but does not free storage
| |
| ; <tt>destroy</tt>
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| : frees storage
| |
| ; indexToAddr
| |
| : Given an index it returns the address of the storage. Note the the generated header files assign an index to each field.
| |
| | |
| === <tt>LinkDbdSupport</tt> ===
| |
| Not yet described
| |
| | |
| === <tt>RecordDbdSupport</tt> ===
| |
| Not yet described
| |
| | |
| | |
| ----
| |
| <center>
| |
| | |
| == Example Database Definition Files ==
| |
| | |
| </center>
| |
| | |
| === Database Definition Files ===
| |
| | |
| <tt>menuAlarmSevr.dbd</tt> contains:
| |
| menu(menuAlarmSevr) {
| |
| choice("NO_ALARM")
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| choice("MINOR")
| |
| choice("MAJOR")
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| choice("INVALID")
| |
| }
| |
| | |
| <tt>displayLimit.dbd</tt> contains:
| |
| struct(displayLimit) {
| |
| field(low,float64)
| |
| field(high,float64)
| |
| }
| |
| <tt>exampleRecord.dbd</tt> contains:
| |
| record(example) extends iocRecord {
| |
| field(value,float64)
| |
| field(displayLimit,struct(displayLimit))
| |
| }
| |
| <tt>alltypesRecord.dbd</tt> contains:
| |
| record(allTypes) extends iocRecord {
| |
| field(fbool,bool)
| |
| field(foctet,octet)
| |
| field(fint16,int16)
| |
| field(fuint16,uint16)
| |
| field(fint32,int32)
| |
| field(fuint32,uint32)
| |
| field(fint64,int64)
| |
| field(fuint64,uint64)
| |
| field(ffloat32,float32)
| |
| field(ffloat64,float64)
| |
| field(fstring,string)
| |
| field(fmenu,menu(menuName))
| |
| field(fenum,enum)
| |
| field(fstruct,struct(displayLimit))
| |
| field(flink,link(dir))
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| field(fdevice,device(dir,interfaceName))
| |
| }
| |
| === Generated Header Files ===
| |
| Tools are provided to generate header files from the following dbd definitions:
| |
| *menu
| |
| *struct
| |
| *record
| |
| <tt>menuAlarmSevr.h</tt> is generated from <tt>menuAlarmSevr.dbd</tt>
| |
| enum menuAlarmSevr {
| |
| menuAlarmSevrNO_ALARM,
| |
| menuAlarmSevrMINOR,
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| menuAlarmSevrMAJOR,
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| menuAlarmSevrINVALID
| |
| };
| |
| <tt>displayLimit.h</tt> is generated from <tt>displayLimit.dbd</tt>
| |
| class displayLimit {
| |
| public:
| |
| dbfFloat64 low;
| |
| dbfFloat64 high;
| |
| };
| |
| const dbfInt16 displayLimit_firstIndex = 1
| |
| const dbfInt16 displayLimit_low = 1
| |
| const dbfInt16 displayLimit_high = 2
| |
| const dbfInt16 displayLimit_lastIndex =displayLimit_high
| |
| <tt>exampleRecord.h</tt> is generated from <tt>exampleRecord.dbd</tt>
| |
| class exampleRecord {
| |
| public:
| |
| ... All the fields from iocRecord.dbd
| |
| dbfFloat64 value;
| |
| dbfStruct displayLimit;
| |
| };
| |
|
| |
| const dbfInt16 example_firstIndex = 1001001
| |
| const dbfInt16 example_low = 1001001;
| |
| const dbfInt16 example_high = 1001002;
| |
| const dbfInt16 example_lastIndex = example_high;
| |
| <tt>alltypesRecord.h</tt> is generated from <tt>alltypesRecord.dbd</tt>
| |
| class allTypesRecord {
| |
| public:
| |
| ... All the fields from iocRecord.dbd
| |
| iocRecord common;
| |
| dbfBoolean fbool;
| |
| dbfOctet foctet;
| |
| dbfInt16 fint16;
| |
| dbfUInt16 fuint16;
| |
| dbfInt32 fint32;
| |
| dbfUInt32 fuint32;
| |
| dbfInt64 fint32;
| |
| dbfUInt64 fuint32;
| |
| dbfFloat32 ffloat32;
| |
| dbfFloat64 ffloat64;
| |
| dbfString fstring;
| |
| dbfMenu fmenu;
| |
| dbfEnum fenum
| |
| dbfStruct fstruct;
| |
| dbfLink flink;
| |
| dbfDevice fdevice;
| |
| };
| |
|
| |
| const dbfInt16 allTypes_firstIndex = 1001001
| |
| const dbfInt16 allTypes_fbool = 1001001;
| |
| const dbfInt16 allTypes_foctet = 1001002;
| |
| const dbfInt16 allTypes_fint16 = 1001003;
| |
| const dbfInt16 allTypes_fuint16 = 1001004;
| |
| const dbfInt16 allTypes_fint32 = 1001005;
| |
| const dbfInt16 allTypes_fuint32 = 1001006;
| |
| const dbfInt16 allTypes_fint64 = 1001007;
| |
| const dbfInt16 allTypes_fuint64 = 1001008;
| |
| const dbfInt16 allTypes_ffloat32 = 1001009;
| |
| const dbfInt16 allTypes_ffloatn64 = 10010010;
| |
| const dbfInt16 allTypes_ffstring = 10010011;
| |
| const dbfInt16 allTypes_fmenu = 10010012;
| |
| const dbfInt16 allTypes_fenum = 10010013;
| |
| const dbfInt16 allTypes_fstruct = 10010014;
| |
| const dbfInt16 allTypes_flink = 10010015
| |
| const dbfInt16 allTypes_fdevice = 10010016
| |
| const dbfInt16 allTypes_lastIndex = allTypes_fdevice;
| |
| | |
| ----
| |
