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| = EPICS: dbdClasses - IOC record =
| | This page is obsolete. It is replaced by dbdInterfaces. |
| June 9 2005
| |
| | |
| ----
| |
| <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 intended for code that:
| |
| * includes header files generated from dbd definitions. Header files are generated from the following dbd definitions:
| |
| ** <tt>record</tt> - Should only be included by record support.
| |
| ** <tt>struct</tt> - Included by code that understands the struct.
| |
| ** <tt>menu</tt> - Included by code that understands the menu.
| |
| * does not include the header files.
| |
| | |
| The following headers files are described:
| |
| * <tt>dbfTypes.h</tt> - Type definitions for <tt>field</tt> definitions in <tt>struct</tt> or <tt>record></tt> DBD definitions.
| |
| * <tt>dbdStatements.h</tt> - Type definitions for DBD statements.
| |
| * <tt>dbdInterfaces.h</tt> - Type definitions for interfaces related to DBD definitions.
| |
| | |
| ----
| |
| <center>
| |
| | |
| == dbfTypes ==
| |
| </center>
| |
| File <tt>dbfTypes.h</tt> describes types and classes that are used in header
| |
| files generated from dbd <tt>struct</tt> or <tt>record</tt> field definitions.
| |
| The following naming conventions are used:
| |
| ; C++ <tt>struct</tt> vs <tt>class</tt>
| |
| : A C++ <tt>class</tt> is used for a class that has methods and <tt>struct</tt> is used for a class that has only data.
| |
| ; Dbf
| |
| : any class starting with Dbf describes a field in a generated header file. For example DbfString describes a field generated from <tt>field(name,string)</tt>.
| |
| ; Dbd
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| : A class name starting with Dbd describes something related to dbd definitions. For example DbdLinkSupport describes a dbd link definition.
| |
| | |
| === <tt>dbfTypes.h</tt> ===
| |
| Every field in the header files generated from DBD <tt>struct</tt> and
| |
| <tt>record</tt> definitions has one on the following types:
| |
| | |
| | |
| enum dbfType {
| |
| dbfTypeBoolean, // epicsBoolean
| |
| dbfTypeOctet, // epicsOctet
| |
| dbfTypeInt16, // epicsInt16
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| dbfTypeInt32, // epicsInt32
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| dbfTypeInt64, // epicsInt64
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| dbfTypeFloat32, // epicsFloat32
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| dbfTypeFloat64, // epicsFloat64
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| dbfTypeString, // EpicsString
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| dbfTypeArray, // DbfArray
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| dbfTypeMDArray // DbfMDArray
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| dbfMenuT, // DbfMenu
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| dbfEnumT, // DbfEnum
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| dbfLinkT, // DbfLink
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| dbfDeviceT // DbfDevice
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| dbfTypeStruct, // DbfStruct
| |
| };
| |
| | |
| === Discussion of dbfTypes ===
| |
| | |
| DBD type
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| * bool,...,string all become an epicsType , i.e. epicsBoolean,...EpicsString
| |
| * array becomes a DbfArray or DbfMDArray.
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| * struct becomes a DbfStruct
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| * menu becomes DbfMenu
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| * enum becomes DbfEnum
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| * link becomes DbfLink
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| * device becomes DbfDevice
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| | |
| | |
| If a record is defined as:
| |
| struct(displayLimits) {
| |
| field(low,double)
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| field(high,double)
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| }
| |
| record(xxx) extends iocRecord {
| |
| ...
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| field(fbool,bool)
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| field(foctet,octet)
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| field(fint,int16)
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| ...
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| field(ffloat,float64)
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| field(fstring,string)
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| field(array,array(double[])
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| field(mdarray,array(double[,])
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| field(fmenu,menu(name))
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| field(fenum,enum)
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| field(flink,link(in))
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| field(fdevice,link(in,analogIO))
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| field(displayLimits,struct(displayLimits))
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| }
| |
| | |
| Then the generated header file will be
| |
| class xxxRecord : public iocRecord {
| |
| public:
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| epicsBoolean fbool;
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| epicsOctet foctet;
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| epicsInt16 fint;
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| ...
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| epicsFloat64 ffloat;
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| EpicsString fstring;
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| DbfArray array;
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| DbfMDArray mdarray;
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| DbfMenu fmenu;
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| DbfEnum fenum;
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| DbfLink flink;
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| DbfDevice fdevice;
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| DbfStruct displayLimits;
| |
| };
| |
| ----
| |
| <center>
| |
| | |
| == epicsTypes ==
| |
| </center>
| |
| | |
| Fields of type epicsBoolean, epicsOctet, epicsInt16, epicsInt32, epicsInt64,
| |
| epicsFloat32, or epicsFloat64 are all a C++ fundamental type. When a record
| |
| instance is created these are all initialized to 0.
| |
| | |
| A field of type EpicsString is initialized via the default constructor for
| |
| EpicsString, which means that no EpicsBuffer is created. Record support
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| must call createBuffer.
| |
| | |
| ----
| |
| <center>
| |
| | |
| == DbfArray ==
| |
| </center>
| |
|
| |
| <tt>DbfArray</tt> is:
| |
| | |
| struct DbfArray {
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| dbfType type;
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| EpicsArray *parray;
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| };
| |
| | |
| In addition the following convenience classes are available .
| |
| | |
| class BasicTypeArray {
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| BasicTypeArray(DbfArray *parray);
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| BasicTypeArray(DbfArray *parray,
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| const char *bufferType, epicsInt32 capacity);
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| BasicTypeArray(DbfArray *parray,
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| BufferCreator *creator, epicsInt32 capacity);
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| virtual ~BasicTypeArray();
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| protected:
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| DbfArray *parray;
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| private:
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| BasicTypeArray(const EpicsBasicTypeArray &);// No copy constructor
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| // No assignment operator
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| BasicTypeArray& operator=(const EpicsBasicTypeArray &);
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| };
| |
| | |
| class Int16Array : public BasicTypeArray {
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| Int16Array();
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| Int16Array(const char *bufferType, epicsInt32 capacity);
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| Int16Array(EpicsBufferCreator *creator, epicsInt32 capacity);
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| ~Int16Array();
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| epicsInt16 * element(epicsInt32 index);
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| const epicsInt16 * element(epicsInt32 index) const;
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| epicsInt32 get(epicsInt32 offset, epicsInt32 len,
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| epicsInt16 *pto) const;
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| epicsInt32 put(epicsInt32 offset, epicsInt32 len,
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| const epicsInt16 *pfrom);
| |
| | |
| // These are similar to Buffer, measured in elements not octets
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| void reserve(epicsInt32 capacity);
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| epicsInt32 capacity() const;
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| void resize(epicsInt32 newsize);
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| epicsInt32 size() const;
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| epicsInt32 maxSize() const;
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| void expose(epicsInt32 offset, epicsInt32 &len,
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| epicsInt16 *&pdata);
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| void expose(epicsInt32 offset, epicsInt32 &len,
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| const epicsInt16 *&pdata) const;
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| private:
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| Int16Array(const EpicsInt16Array &); // No copy constructor
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| Int16Array& operator=(const EpicsInt16Array &); // No assignment operator
| |
| };
| |
| | |
| class OctetArray ;
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| class Int32Array ;
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| class Int64Array ;
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| class Float32Array ;
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| class Float64Array ;
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| class StringArray ;
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| class StructArray ;
| |
| | |
|
| |
| ----
| |
| <center>
| |
| | |
| == DbfMDArray ==
| |
| </center>
| |
| | |
| <tt>DbfMDArray</tt> is:
| |
| | |
| struct DbfMDArray {
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| dbfType type;
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| EpicsMDArray *parray;
| |
| };
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|
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| Need something like for DbfArray except that convenience classes will be
| |
| | |
| class BasicTypeMDArray;
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| class OctetMDArray ;
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| class Int32MDArray ;
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| class Int64MDArray ;
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| class Float32MDArray ;
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| class Float64MDArray ;
| |
|
| |
| ----
| |
| <center>
| |
| | |
| == DbfMenu ==
| |
| </center>
| |
| <tt>DbfMenu</tt> is described as:
| |
| struct DbfMenu{
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| epicsInt16 index;
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| DbdMenu *pmenuDef;
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| };
| |
| | |
| <tt>DbfMenu</tt> provides the current menu index and also the menu definition.
| |
| | |
| A field of type DbfMenu is automatically initialized by dbLoadRecords.
| |
| | |
| ----
| |
| <center>
| |
| | |
| == DbfEnum ==
| |
| </center>
| |
| <tt>DbfEnum</tt> is described as:
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| struct DbfEnum{
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| epicsInt16 index;
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| DbfArray *pfield; //EpicsArray of epicsTypeString
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| };
| |
| | |
| <tt>pfield</tt> is the address of a field in the same record that is a
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| DbfArray of type EpicsString. It contains the choices.
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| | |
| A field of type DbfEnum is automatically initialized by dbLoadRecords.
| |
| | |
| ----
| |
| <center>
| |
| | |
| == DbfLink and DbdDevice ==
| |
| </center>
| |
|
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|
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| <tt>DbfLink</tt> is described as
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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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|
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| struct DbfLink{
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| LinkDir dir;
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| DbdLink *plinkDef;
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| DbfStruct dataStruct;
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| };
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|
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| struct DbfDevice{
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| LinkDir dir;
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| DbdDevice *pDbdDevice;
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| DbfStruct dataStruct;
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| };
| |
| | |
| The fields of <tt>DbfLink</tt> are initialized by dbLoadRecords 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>DbdLink</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>plinkDef</tt>
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| : This is the address of the <tt>DbdLink</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.
| |
| | |
| Link support always implements interface <tt>DbdLinkSupport</tt>
| |
| | |
| 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>DbdLinkSupport</tt>, the device support implements an interface that both record support and device support understand.
| |
| | |
| | |
| ----
| |
| <center>
| |
| | |
| == DbfStruct ==
| |
| </center>
| |
| <tt>DbfStruct</tt> is described as
| |
| | |
| struct DbfStruct {
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| DbdStruct *pdescription;
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| void *pstorage;
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| };
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|
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| The fields of <tt>DbfStruct</tt> are initialized by dbLoadRecords as follows:
| |
| ; <tt>pdescription</tt>
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| : This is initialized via the structure name specified in field definition.
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| ; <tt>pstorage
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| : This is initialized by calling DbdStructLifetime:allocate
| |
| | |
| ----
| |
| <center>
| |
| | |
| == dbdStatements ==
| |
| | |
| </center>
| |
| The definitions in <tt>dbdStatements.h</tt> allow introspection of ioc records. They describe everything defined in DBD definitions.
| |
| | |
| <b>NODE</b> and <b>LIST</b> specify a doubly linked list.
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| An implementation is not specified.
| |
| | |
| === <tt>dbdStatements.h</tt> ===
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| | |
| class Interface {}; // Must be an interface, i.e. pure abstract class
| |
| | |
| struct DbdMenu{
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| NODE node; // for DbdBase:menuList
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| EpicsString name;
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| epicsInt16 nchoices;
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| EpicsString *pchoice[];
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| };
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|
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| struct DbdLink{ //describes dbd link statement
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| public:
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| NODE node; // For DbdBase:linkList
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| LinkDir dir;
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| EpicsString choiceName;
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| EpicsString dataStructName;
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| DbdLinkSupport *pinterface;
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| };
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|
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| struct DbdDevice { //describes dbd device statement
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| NODE node; // For DbdBase:deviceList
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| LinkDir dir;
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| EpicsString choiceName;
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| EpicsString dataStructName;
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| EpicsString interfaceName;
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| Interface *pinterface;
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| };
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| | |
|
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| // Beginning of definitions for DbdStruct
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| struct DbdAttribute {
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| EpicsString default;
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| epicsBoolean readonly;
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| epicsBoolean design;
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| epicsBoolean special;
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| epicsBoolean dynamic;
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| epicsInt16 asl;
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| };
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| | |
| struct DbdStringDefaults { // defaults for string
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| const char *bufferType;
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| epicsInt32 capacity;
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| };
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| | |
| struct DbdArrayDefaults { // defaults for array
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| dbfType type;
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| const char *bufferType;
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| epicsInt32 capacity;
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| epicsInt32 nelements;
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| };
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| | |
| struct DbdMDArrayDefaults { // defaults for mdarray
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| dbfType type;
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| epicsInt16 ndim
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| const char *bufferType;
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| epicsInt32 capacity;
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| };
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| | |
| struct DbdStructDefaults { // defaults for struct
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| DbdStruct *pdescription;
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| };
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| | |
| struct DbdField {
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| const char *name;
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| dbfType type;
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| union {
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| DbdStringDefaults *pstring;
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| DbdArrayDefaults *parray;
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| DbdMDArrayDefaults *pmdarray;
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| DbdStructDefaults *pstruct;
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| } defaults;
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| DbdAttribute attribute;
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| };
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| | |
| struct DbdStruct{ // describes a struct
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| NODE node; // for DbdBase:structList
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| const char *name;
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| epicsInt16 nfields;
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| DbdField *pafield;//ptr to array of DbdField
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| DbdStructLifetime *plifetime;
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| };
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| | |
| | |
| struct DbdRecord { // describes a record
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| NODE node; // for DbdBase:recordList
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| LIST instanceList;
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| const char *name;
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| epicsInt16 nfields;
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| DbdField *pafield;//ptr to array of DbdField
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| DbdRecordSupport *psupport;
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| DbdRecordLifetime *plifetime;
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| };
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|
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| struct DbdUserField{ // describes a dbd userField statement
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| NODE node; // For DbdBase:userFieldList
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| EpicsString choiceName;
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| epicsType type;
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| EpicsString dataStructName;
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| DbdUserFieldHandler *pinterface;
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| };
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|
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| // The following describes a record instance
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| struct DbdUserFieldInstance {
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| public:
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| NODE node; // for DbdRecordInstance.userField
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| EpicsString name; // field name
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| DbdUserField *pDbdUserField;
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| void *pstorage; // for DbdUserField.type
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| DbfStruct dataStruct;
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| };
| |
|
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| struct DbdRecordInstance {
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| NODE node; // for DbdRecord.instanceList
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| DbdRecord *pDbdRecord;
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| void *pstorage;
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| EpicsString name;
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| LIST userField; // of DbdUserFieldInstance
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| };
| |
|
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| struct DbdBase {
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| LIST structList;
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| LIST recordList;
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| LIST menuList;
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| LIST linkList;
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| LIST deviceList;
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| LIST userFieldList;
| |
| };
| |
| | |
| | |
| === Discussion of dbdStatements ===
| |
| | |
| ==== Menu ====
| |
| | |
| A dbd <tt>menu</tt> is described by class <tt>DbdMenu</tt>
| |
| | |
| The fields of DbdMenu are:
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| ; <tt>node</tt>
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| : node for DbdBase:menuList
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| ; <tt>name</tt>
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| : The menu name.
| |
| ; <tt>nchoices</tt>
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| : The number of menu choices.
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| ; <tt>pchoice</tt>
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| : The address of an array of pointers to EpicsString. Each EpicsString is a choice.
| |
| | |
| ==== Link ====
| |
| | |
| A dbd <tt>link</tt> definition is described by class <tt>DbdLink</tt>
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| ; <tt>node</tt>
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| : This is a node for <tt>DbdLinkList</tt>
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| ; <tt>dir</tt>
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| : The link direction
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| ; <tt>choiceName</tt>
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| : The name that connects a DbdLink to a DbfLink instance.
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| ; <tt>dataStructName</tt>
| |
| : The class name of an DbdStruct for the Interface implementation
| |
| ; <tt>pinterface</tt>
| |
| : The address of the DbdLinkSupport Interface implementation.
| |
| | |
| ==== Device ====
| |
| | |
| Each dbd <tt>device</tt> definition has an associated class <tt>DbdDevice</tt> with fields:
| |
| ; <tt>node</tt>
| |
| : This is a node for <tt>DbdDeviceList</tt>
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| ; <tt>dir</tt>
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| : The link direction
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| ; <tt>choiceName</tt>
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| : The name that matches a DbdDevice to a DbfDevice instance.
| |
| ; <tt>dataStructName</tt>
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| : The class name of an EpicsStruct for the Interface implementation
| |
| ; <tt>interfaceName</tt>
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| : The name of the interface type implemented by the device support
| |
| ; <tt>pinterface</tt>
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| : The address of the Interface implementation.
| |
| | |
| | |
| ==== struct and record ====
| |
| The following classes describe the fields in a dbd <tt>struct</tt> or <tt>record</tt> definition: <tt>DbdStruct</tt>, <tt>DbdRecord</tt>, <tt>DbdField</tt>,and <tt>DbdAttribute</tt>
| |
| | |
| The fields of <tt>DbdStruct</tt> are:
| |
| ; <tt>node</tt>
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| : node for <tt>DbdBase:structList</tt>
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| ; <tt>name</tt>
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| : The name of the struct.
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| ; <tt>nfields</tt>
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| : The number of fields, e.g. fields in the structure.
| |
| ; <tt>pafields</tt>
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| : pointer to an array of <tt>DbdField</tt>.
| |
| ; <tt>plifetime</tt>
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| : The address of an implementation of interface <tt>DbdStructLifetime</tt>. The implementation is automatically generated from the dbd <tt>struct</tt>. See below for a description of the Lifetime methods.
| |
| | |
| The fields of <tt>DbdRecord</tt> are;
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| ; <tt>node</tt>
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| : node for <tt>DbdBase:recordList</tt>
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| ; <tt>instanceList</tt>
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| : list of instances of this record type
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| ; <tt>name</tt>
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| : The name of the record type.
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| ; <tt>nfields</tt>
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| : The number of fields, e.g. fields in the record.
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| ; <tt>pafields</tt>
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| : pointer to an array of <tt>DbdField</tt>.
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| ; <tt>psupport</tt>
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| : The address of the <tt>DbdRecordSupport</tt> for this record type.
| |
| ; <tt>plifetime</tt>
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| : The address of an implementation of interface <tt>DbdRecordLifetime</tt>. The implementation is automatically generated from the dbd <tt>record</tt> statement. See below for a description of the Lifetime methods.
| |
| | |
| | |
| The fields of <tt>DbdField</tt> are:
| |
| ; <tt>name</tt>
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| : The name of the field
| |
| ; <tt>type</tt>
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| : The dbfType of the field.
| |
| : <tt>defaults</tt>
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| ; a union of default values. The default values depend on the record type definitions. Most types do not have associated default values. Note that these are defaults for the description of the field NOT for values to put in the field.
| |
| ; <tt>attribute</tt>
| |
| : DbdAttribute for the field
| |
| | |
| The fields of <tt>DbdAttribute</tt> are:
| |
| ; <tt>default</tt>
| |
| : An EpicsString providing a default value for the field.
| |
| ; <tt>readonly</tt>
| |
| : Is the field readonly?
| |
| ; <tt>design</tt>
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| : Is the field a design fields for DCTs?
| |
| ; <tt>special</tt>
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| : Should DbdRecordSupport:special be called if the field is modified.
| |
| ; <tt>dynamic</tt>
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| : Can the field change because of record processing?
| |
| ; <tt>asl</tt>
| |
| : The access security level.
| |
| ==== User Defined Fields ====
| |
| | |
| Each dbd <tt>userField</tt> definition has an associated class <tt>DbdUserField</tt> with fields:
| |
| ; <tt>node</tt>
| |
| : This is a node for <tt>DbdUserFieldList</tt>
| |
| ; <tt>choiceName</tt>
| |
| : The name that matches a DbdUserField to a DbdUserFieldInstance
| |
| ; <tt>type</tt>
| |
| : The epicsType for the user field
| |
| ; <tt>dataStructName</tt>
| |
| : The class name of an EpicsStruct for the DbdUserFieldHandler
| |
| ; <tt>pinterface</tt>
| |
| : The address of the DbdUserFieldHandler implementation.
| |
| | |
| ==== Record Instance ====
| |
| | |
| A record instance has two associated classes:<tt>DbdUserFieldInstance</tt> and <tt>DbdRecordInstance</tt>.
| |
| | |
| <tt>DbdUserFieldInstance</tt> contains information for a user defined field:
| |
| ; <tt>node</tt>
| |
| : A node for list <tt>DbdRecordInstance.userField</tt>
| |
| ; <tt>name</tt>
| |
| : The name of the user defined field, i.e. the psuedo field name
| |
| ; <tt>pDbdUserField</tt>
| |
| : The DbdUserField that describes the field
| |
| ; <tt>pstorage</tt>
| |
| : Address of storage for the dbfType.
| |
| ; <tt>dataStruct</tt>
| |
| : An DbfStruct that holds the private data for the DbdUserFieldHandler.
| |
| | |
| The fields of <tt>DbdRecordInstance</tt> are:
| |
| | |
| ; <tt>node</tt>
| |
| : A node for list <tt>DbdRecord.instanceList</tt>
| |
| ; <tt>pDbdRecord</tt>
| |
| : address of the DbdRecord describing the record
| |
| ; <tt>pstorage</tt>
| |
| ; address of the storage for the record instance
| |
| ; <tt>name</tt>
| |
| : The name of the record instance
| |
| ; <tt>userField</tt>
| |
| : <tt>DbdUserFieldInstance</tt> list for the record instance.
| |
| | |
| ==== DbdBase ====
| |
| | |
| The following provide lists of various things:
| |
| | |
| ; <tt>structList</tt>
| |
| : The list of each struct definition
| |
| ; <tt>recordList</tt>
| |
| : The list of each record type definition
| |
| ; <tt>menuList</tt>
| |
| : The list of each menu definition
| |
| ; <tt>linkList</tt>
| |
| : The list of each link definition
| |
| ; <tt>deviceList</tt>
| |
| : The list of each device definition
| |
| ; <tt>userFieldList</tt>
| |
| : The list of each DbdUserField definition
| |
| | |
| ----
| |
| <center>
| |
| | |
| == dbdInterfaces ==
| |
| | |
| dbdInterfaces describes standard interfaces implemented by code that
| |
| supports runtime database access.
| |
| | |
| </center>
| |
| | |
| === <tt>dbdInterfaces.h</tt> ===
| |
| <tt>dbdInterfaces.h</tt> contains the following:
| |
| | |
| // The following is implemented by database access
| |
| class DbdFieldPutString {
| |
| virtual void primitive(EpicsString *pfrom, dbfType type,
| |
| void *pstorage) = 0;
| |
| virtual void string(EpicsString *pfrom,
| |
| EpicsString *pEpicsString) = 0;
| |
| virtual void array(EpicsString *pfrom,
| |
| DbfArray *parray) = 0;
| |
| virtual void dbfStruct(EpicsString *pfrom,
| |
| DbfStruct *pstruct) = 0;
| |
| virtual void dbfMDArray(EpicsString *pfrom,
| |
| DbfMDArray *parray) = 0;
| |
| }
| |
| | |
| // For struct definitions
| |
| // An DbdStructLifetime interface is automatically generated.
| |
| class DbdStructLifetime {
| |
| public:
| |
| virtual void allocate(DbfStruct &struct) = 0;
| |
| virtual void destroy(DbfStruct &struct) = 0;
| |
| virtual bool initialize(DbfStruct *pDbfStruct) = 0;
| |
| virtual bool finalize(DbfStruct *pDbfStruct) = 0;
| |
| virtual void *exposeField(DbfStruct &struct, epicsInt16 index) = 0;
| |
| };
| |
| | |
| // For record definitions a DbdRecordLifetime is automatically generated.
| |
| class DbdRecordLifetime{
| |
| public:
| |
| virtual void allocate(DbfStruct &struct) = 0;
| |
| virtual void destroy(DbfStruct &struct) = 0;
| |
| virtual bool initialize(DbdRecordInstance *pDbdRecordInstance) = 0;
| |
| virtual bool finalize(DbdRecordInstance *pDbdRecordInstance) = 0;
| |
| virtual void *exposeField(DbfStruct &struct, epicsInt16 index) = 0;
| |
| };
| |
| | |
| // link support modules implement the following interface
| |
| class DbdLinkSupport {
| |
| public:
| |
| virtual void report(iocRecord *precord, DbfLink *pdbfLink) = 0;
| |
| virtual bool initialize(EpicsString *errorMessage,
| |
| iocRecord *precord, DbfLink *pdbfLink) = 0;
| |
| virtual bool finalize(EpicsString *errorMessage,
| |
| iocRecord *precord, DbfLink *pdbfLink) = 0;
| |
| virtual bool connect(EpicsString *errorMessage,
| |
| iocRecord *precord, DbfLink *pdbfLink) = 0;
| |
| virtual bool disconnect(EpicsString *errorMessage,
| |
| iocRecord *precord, DbffLink *pdbfLink) = 0;
| |
| virtual bool get(EpicsString *errorMessage,
| |
| iocRecord *precord, DbffLink *pdbfLink,
| |
| epicsType type, void *pfield) = 0;
| |
| virtual bool put(EpicsString *errorMessage,
| |
| iocRecord *precord, DbfLink *pdbfLink,
| |
| epicsType type, void *pfield) = 0;
| |
| };
| |
| | |
| /* record support implements the following*/
| |
| class DbdRecordSupport {
| |
| public:
| |
| virtual bool initBuffers(DbdRecordInstance *pDbdRecordInstance) = 0;
| |
| virtual bool initConnections(DbdRecordInstance *pDbdRecordInstance) = 0;
| |
| virtual bool breakConnections(DbdRecordInstance *pDbdRecordInstance) = 0;
| |
| virtual bool process(DbdRecordInstance *pDbdRecordInstance) = 0;
| |
| virtual void special(DbdRecordInstance *pDbdRecordInstance,
| |
| bool after,
| |
| epicsInt16 nlevels, // number of elements in fieldIndex
| |
| epicsInt16 fieldIndex[] // array of field indices
| |
| ) = 0;
| |
| };
| |
| | |
| class DbdUserFieldHandler {
| |
| public:
| |
| virtual bool initialize(EpicsString *errorMessage,
| |
| iocRecord *precord,DbdUserFieldInstance *puserField) = 0;
| |
| virtual bool finalize(EpicsString *errorMessage,
| |
| iocRecord *precord,DbdUserFieldInstance *puserField) = 0;
| |
| virtual bool process(EpicsString *errorMessage,
| |
| iocRecord *precord,DbdUserFieldInstance *puserField) = 0;
| |
| };
| |
| | |
| === Discussion of dbdInterfaces ===
| |
| | |
| === <tt>DbdFieldPutString</tt> ===
| |
| | |
| This is an interface, which has an implementation provided by iocCore,
| |
| that convert an <tt>EpicsString</tt> to an dbfType.
| |
| The methods are:
| |
| ; <tt>primitive</tt>
| |
| : This convert a string to one of the types: <tt>epicsBoolean</tt>, ..., <epicsFloat64</tt>
| |
| ; <tt>string</tt>
| |
| : Copies an EpicsString to an EpicsString
| |
| ; <tt>array</tt>
| |
| : Accepts a string that has the DBD array initialization syntax, locates the string value for each element and calls either DbdFieldPutString:primitive or DbdFieldPutString:string to convert the value and put it into the correct element of <tt>DbfArray</tt>
| |
| ; <tt>dbfStruct</tt>
| |
| : Accepts a string that has the DBD struct initialialization syntax, locates the string value associated with each field and calls primitive, string, or array to convert the value and put the result of the correct field of <tt>DbfStruct</tt>
| |
| ; <tt>dbfMDArray</tt>
| |
| : Accepts a string that has the DBD array initialization syntax, locates the string value for each element and calls either DbdFieldPutString:primitive or DbdFieldPutString:string to convert the value and put it into the correct element of <tt>DbfMDArray</tt>
| |
| === <tt>DbdStructLifetime</tt> and <tt>DbdRecordLifetime</tt> ===
| |
| Every dbd <tt>struct</tt> and <tt>record</tt> has an associated Lifetime interface implementation.
| |
| A tool is provided that automatically generates the implementation from the dbd definition.
| |
| | |
| <tt>DbdStructLifetime</tt> and <tt>DbdRecordLifetime</tt> each has the following fields:
| |
| ; <tt>allocate</tt>
| |
| : Creates storage for the struct or record.
| |
| ; <tt>destroy</tt>
| |
| : frees storage
| |
| ; <tt>exposeField</tt>
| |
| : Given an index it returns the address of the storage for the field. Note the the generated header files assign an index to each field.
| |
| ; <tt>initialize</tt>
| |
| : initializes the struct or record
| |
| ; <tt>finalize</tt>
| |
| : cleans up but does not free storage
| |
| | |
| === <tt>DbdLinkSupport</tt> ===
| |
| | |
| This is the interface implemented by the support associated with each DBD link.
| |
| | |
| <tt>DbdLinkSupport</tt> has the following methods:
| |
| ; <tt>report</tt>
| |
| : generate a report about the link instance
| |
| ; <tt>initialize</tt>
| |
| : perform initialization but do not connect
| |
| ; <tt>finalize</tt>
| |
| : undo initialization. It is assumed that disconnect has already been called.
| |
| ; <tt>connect</tt>
| |
| : connect to external source of data
| |
| ; <tt>disconnect</tt>
| |
| : disconnect from external source of data
| |
| ; <tt>get</tt>
| |
| : get a value from the external source. <tt>type</tt> specified the field type and <tt>pfield</tt> is the address of where to store the data.
| |
| ; <tt>put</tt>
| |
| : put a value from the external source. <tt>type</tt> specified the field type and <tt>pfield</tt> is the address of where to obtain the data.
| |
| === <tt>DbdRecordSupport</tt> ===
| |
| | |
| This is the interface implemented by each record support module.
| |
| <tt>DbdRecordSupport</tt> has the following methods:
| |
| | |
| ; <tt>initBuffers</tt>
| |
| : This is called during record initialization. It is responsible for creating the buffers associated with each string and array field. It may call associated support to do the initialization.
| |
| ; <tt>initConnections</tt>
| |
| : This is called to connect to external sources. It may call associated support to make the connections.
| |
| ; <tt>breakConnections</tt>
| |
| : This is called to disconnect to external sources. It may call associated support to break the connections.
| |
| ; <tt>process</tt>
| |
| : Process the record.
| |
| ; <tt>special</tt>
| |
| : This is called whenever an external source modifies a field with attribute special set to true.
| |
| | |
| | |
| === <tt>DbdUserFieldHandler</tt> ===
| |
| This is the interface implemented by code for user extensible fields.
| |
| | |
| <tt>DbdUserFieldHandler</tt> has the following fields:
| |
| ; <tt>initialize</tt>
| |
| : Initialize the user field.
| |
| ; <tt>finalize</tt>
| |
| : undo what was done during initialization
| |
| ; <tt>process</tt>
| |
| : Called near the end of record processing just before monitors are handled.
| |
| | |
| === Device Support Interfaces ===
| |
| | |
| Multiple interface definitions for device support will be defined.
| |
| Record Support and device support must agree on which interface type
| |
| is used for communication.
| |
| ----
| |
