Add an "events" system to libpq, whereby applications can get callbacks that

enable them to manage private data associated with PGconns and PGresults.

Andrew Chernow and Merlin Moncure

1 files changed, 91 insertions, 0 deletions

diff --git a/src/interfaces/libpq/libpq-events.h b/src/interfaces/libpq/libpq-events.h
new file mode 100644
index 0000000000..33e2d5b046
--- /dev/null
+++ b/src/interfaces/libpq/libpq-events.h
@@ -0,0 +1,91 @@
+/*-------------------------------------------------------------------------
+ *
+ * libpq-events.h
+ *	  This file contains definitions that are useful to applications
+ *	  that invoke the libpq "events" API, but are not interesting to
+ *	  ordinary users of libpq.
+ *
+ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-events.h,v 1.1 2008/09/17 04:31:08 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef LIBPQ_EVENTS_H
+#define LIBPQ_EVENTS_H
+
+#include "libpq-fe.h"
+
+#ifdef __cplusplus
+extern		"C"
+{
+#endif
+
+/* Callback Event Ids */
+typedef enum
+{
+	PGEVT_REGISTER,
+	PGEVT_CONNRESET,
+	PGEVT_CONNDESTROY,
+	PGEVT_RESULTCREATE,
+	PGEVT_RESULTCOPY,
+	PGEVT_RESULTDESTROY
+} PGEventId;
+
+typedef struct
+{
+	const PGconn *conn;
+} PGEventRegister;
+
+typedef struct
+{
+	const PGconn *conn;
+} PGEventConnReset;
+
+typedef struct
+{
+	const PGconn *conn;
+} PGEventConnDestroy;
+
+typedef struct
+{
+	const PGconn *conn;
+	PGresult *result;
+} PGEventResultCreate;
+
+typedef struct
+{
+	const PGresult *src;
+	PGresult *dest;
+} PGEventResultCopy;
+
+typedef struct
+{
+	const PGresult *result;
+} PGEventResultDestroy;
+
+typedef int (*PGEventProc) (PGEventId evtId, void *evtInfo, void *passThrough);
+
+/* Registers an event proc with the given PGconn. */
+extern int	PQregisterEventProc(PGconn *conn, PGEventProc proc,
+								const char *name, void *passThrough);
+
+/* Sets the PGconn instance data for the provided proc to data. */
+extern int	PQsetInstanceData(PGconn *conn, PGEventProc proc, void *data);
+
+/* Gets the PGconn instance data for the provided proc. */
+extern void *PQinstanceData(const PGconn *conn, PGEventProc proc);
+
+/* Sets the PGresult instance data for the provided proc to data. */
+extern int	PQresultSetInstanceData(PGresult *result, PGEventProc proc, void *data);
+
+/* Gets the PGresult instance data for the provided proc. */
+extern void *PQresultInstanceData(const PGresult *result, PGEventProc proc);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LIBPQ_EVENTS_H */