The YAZ C++ API is an client - and server API that exposes all YAZ features. The API doesn't hide YAZ C data structures, but provides a set of useful high-level objects for creating clients - and servers.
The following sections include a short description of the interfaces and implementations (concrete classes).
In order to understand the structure, you should look at the example client yaz-my-client.cpp and the example server yaz-my-server.cpp. If that is too easy, you can always turn to the implementation of the proxy itself and send us a patch if you implement a new useful feature.
Note: The documentation here is very limited. We plan to enhance it - provided there is interest for it.
This interface is capable of observing sockets. When a socket even occurs it invokes an object implementing the IYazSocketObserver interface.
#include <yaz++/socket-observer.h>
class my_socketobservable : public IYazSocketObservable {
// Add an observer interested in socket fd
virtual void addObserver(int fd, IYazSocketObserver *observer) = 0;
// Delete an observer
virtual void deleteObserver(IYazSocketObserver *observer) = 0;
// Delete all observers
virtual void deleteObservers() = 0;
// Specify the events that the observer is interested in.
virtual void maskObserver(IYazSocketObserver *observer,
int mask) = 0;
// Specify timeout
virtual void timeoutObserver(IYazSocketObserver *observer,
unsigned timeout)=0;
};
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This interface is interested in socket events supporting the IYazSocketObservable interface.
#include <yaz++/socket-observer.h>
class my_socketobserver : public IYazSocketObserver {
public:
// Notify the observer that something happened to socket
virtual void socketNotify(int event) = 0;
}
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This interface is is responsible for sending - and receiving PDUs over the network (YAZ COMSTACK). When events occur, an instance implementing IYaz_PDU_Observer is notified.
#include <yaz++/pdu-observer.h>
class my_pduobservable : public IYaz_PDU_Observable {
public:
// Send encoded PDU buffer of specified length
virtual int send_PDU(const char *buf, int len) = 0;
// Connect with server specified by addr.
virtual void connect(IYaz_PDU_Observer *observer,
const char *addr) = 0;
// Listen on address addr.
virtual void listen(IYaz_PDU_Observer *observer, const char *addr)=0;
// Close connection
virtual void close() = 0;
// Make clone of this object using this interface
virtual IYaz_PDU_Observable *clone() = 0;
// Destroy completely
virtual void destroy() = 0;
// Set Idle Time
virtual void idleTime (int timeout) = 0;
};
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This interface is interested in PDUs and using an object implementing IYaz_PDU_Observable.
#include <yaz++/pdu-observer.h>
class my_pduobserver : public IYaz_PDU_Observer {
public:
// A PDU has been received
virtual void recv_PDU(const char *buf, int len) = 0;
// Called when Iyaz_PDU_Observable::connect was successful.
virtual void connectNotify() = 0;
// Called whenever the connection was closed
virtual void failNotify() = 0;
// Called whenever there is a timeout
virtual void timeoutNotify() = 0;
// Make clone of observer using IYaz_PDU_Observable interface
virtual IYaz_PDU_Observer *sessionNotify(
IYaz_PDU_Observable *the_PDU_Observable, int fd) = 0;
};
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#include <yaz++/query.h>
class my_query : public Yaz_Query {
public:
// Print query in buffer described by str and len
virtual void print (char *str, int len) = 0;
};
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