diff options
Diffstat (limited to 'libpq/libpq-events.c')
| -rw-r--r-- | libpq/libpq-events.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/libpq/libpq-events.c b/libpq/libpq-events.c new file mode 100644 index 0000000..6db3e94 --- /dev/null +++ b/libpq/libpq-events.c @@ -0,0 +1,209 @@ +/*------------------------------------------------------------------------- + * + * libpq-events.c + * functions for supporting the libpq "events" API + * + * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/interfaces/libpq/libpq-events.c + * + *------------------------------------------------------------------------- + */ +#include "postgres_fe.h" + +#include "libpq-fe.h" +#include "libpq-int.h" + + +/* + * Registers an event proc with the given PGconn. + * + * The same proc can't be registered more than once in a PGconn. This + * restriction is required because we use the proc address to identify + * the event for purposes such as PQinstanceData(). + * + * The name argument is used within error messages to aid in debugging. + * A name must be supplied, but it needn't be unique. The string is + * copied, so the passed value needn't be long-lived. + * + * The passThrough argument is an application specific pointer and can be set + * to NULL if not required. It is passed through to the event proc whenever + * the event proc is called, and is not otherwise touched by libpq. + * + * The function returns a non-zero if successful. If the function fails, + * zero is returned. + */ +int +PQregisterEventProc(PGconn *conn, PGEventProc proc, + const char *name, void *passThrough) +{ + int i; + PGEventRegister regevt; + + if (!proc || !conn || !name || !*name) + return FALSE; /* bad arguments */ + + for (i = 0; i < conn->nEvents; i++) + { + if (conn->events[i].proc == proc) + return FALSE; /* already registered */ + } + + if (conn->nEvents >= conn->eventArraySize) + { + PGEvent *e; + int newSize; + + newSize = conn->eventArraySize ? conn->eventArraySize * 2 : 8; + if (conn->events) + e = (PGEvent *) realloc(conn->events, newSize * sizeof(PGEvent)); + else + e = (PGEvent *) malloc(newSize * sizeof(PGEvent)); + + if (!e) + return FALSE; + + conn->eventArraySize = newSize; + conn->events = e; + } + + conn->events[conn->nEvents].proc = proc; + conn->events[conn->nEvents].name = strdup(name); + if (!conn->events[conn->nEvents].name) + return FALSE; + conn->events[conn->nEvents].passThrough = passThrough; + conn->events[conn->nEvents].data = NULL; + conn->events[conn->nEvents].resultInitialized = FALSE; + conn->nEvents++; + + regevt.conn = conn; + if (!proc(PGEVT_REGISTER, ®evt, passThrough)) + { + conn->nEvents--; + free(conn->events[conn->nEvents].name); + return FALSE; + } + + return TRUE; +} + +/* + * Set some "instance data" for an event within a PGconn. + * Returns nonzero on success, zero on failure. + */ +int +PQsetInstanceData(PGconn *conn, PGEventProc proc, void *data) +{ + int i; + + if (!conn || !proc) + return FALSE; + + for (i = 0; i < conn->nEvents; i++) + { + if (conn->events[i].proc == proc) + { + conn->events[i].data = data; + return TRUE; + } + } + + return FALSE; +} + +/* + * Obtain the "instance data", if any, for the event. + */ +void * +PQinstanceData(const PGconn *conn, PGEventProc proc) +{ + int i; + + if (!conn || !proc) + return NULL; + + for (i = 0; i < conn->nEvents; i++) + { + if (conn->events[i].proc == proc) + return conn->events[i].data; + } + + return NULL; +} + +/* + * Set some "instance data" for an event within a PGresult. + * Returns nonzero on success, zero on failure. + */ +int +PQresultSetInstanceData(PGresult *result, PGEventProc proc, void *data) +{ + int i; + + if (!result || !proc) + return FALSE; + + for (i = 0; i < result->nEvents; i++) + { + if (result->events[i].proc == proc) + { + result->events[i].data = data; + return TRUE; + } + } + + return FALSE; +} + +/* + * Obtain the "instance data", if any, for the event. + */ +void * +PQresultInstanceData(const PGresult *result, PGEventProc proc) +{ + int i; + + if (!result || !proc) + return NULL; + + for (i = 0; i < result->nEvents; i++) + if (result->events[i].proc == proc) + return result->events[i].data; + + return NULL; +} + +/* + * Fire RESULTCREATE events for an application-created PGresult. + * + * The conn argument can be NULL if event procedures won't use it. + */ +int +PQfireResultCreateEvents(PGconn *conn, PGresult *res) +{ + int i; + + if (!res) + return FALSE; + + for (i = 0; i < res->nEvents; i++) + { + if (!res->events[i].resultInitialized) + { + PGEventResultCreate evt; + + evt.conn = conn; + evt.result = res; + if (!res->events[i].proc(PGEVT_RESULTCREATE, &evt, + res->events[i].passThrough)) + return FALSE; + + res->events[i].resultInitialized = TRUE; + } + } + + return TRUE; +} |