Refactor query cancellation code into src/fe_utils/

Originally, this code was duplicated in src/bin/psql/ and
src/bin/scripts/, but it can be useful for other frontend applications,
like pgbench.  This refactoring offers the possibility to setup a custom
callback which would get called in the signal handler for SIGINT or when
the interruption console events happen on Windows.

Author: Fabien Coelho, with contributions from Michael Paquier
Reviewed-by: Álvaro Herrera, Ibrar Ahmed
Discussion: https://postgr.es/m/alpine.DEB.2.21.1910311939430.27369@lancre

1 files changed, 0 insertions, 147 deletions

diff --git a/src/bin/scripts/common.c b/src/bin/scripts/common.c
index 1b38a1da494..d2a7547441a 100644
--- a/src/bin/scripts/common.c
+++ b/src/bin/scripts/common.c
@@ -24,14 +24,6 @@
 
 #define ERRCODE_UNDEFINED_TABLE  "42P01"
 
-
-static PGcancel *volatile cancelConn = NULL;
-bool		CancelRequested = false;
-
-#ifdef WIN32
-static CRITICAL_SECTION cancelConnLock;
-#endif
-
 /*
  * Provide strictly harmonized handling of --help and --version
  * options.
@@ -465,142 +457,3 @@ yesno_prompt(const char *question)
 			   _(PG_YESLETTER), _(PG_NOLETTER));
 	}
 }
-
-/*
- * SetCancelConn
- *
- * Set cancelConn to point to the current database connection.
- */
-void
-SetCancelConn(PGconn *conn)
-{
-	PGcancel   *oldCancelConn;
-
-#ifdef WIN32
-	EnterCriticalSection(&cancelConnLock);
-#endif
-
-	/* Free the old one if we have one */
-	oldCancelConn = cancelConn;
-
-	/* be sure handle_sigint doesn't use pointer while freeing */
-	cancelConn = NULL;
-
-	if (oldCancelConn != NULL)
-		PQfreeCancel(oldCancelConn);
-
-	cancelConn = PQgetCancel(conn);
-
-#ifdef WIN32
-	LeaveCriticalSection(&cancelConnLock);
-#endif
-}
-
-/*
- * ResetCancelConn
- *
- * Free the current cancel connection, if any, and set to NULL.
- */
-void
-ResetCancelConn(void)
-{
-	PGcancel   *oldCancelConn;
-
-#ifdef WIN32
-	EnterCriticalSection(&cancelConnLock);
-#endif
-
-	oldCancelConn = cancelConn;
-
-	/* be sure handle_sigint doesn't use pointer while freeing */
-	cancelConn = NULL;
-
-	if (oldCancelConn != NULL)
-		PQfreeCancel(oldCancelConn);
-
-#ifdef WIN32
-	LeaveCriticalSection(&cancelConnLock);
-#endif
-}
-
-#ifndef WIN32
-/*
- * Handle interrupt signals by canceling the current command, if a cancelConn
- * is set.
- */
-static void
-handle_sigint(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-	char		errbuf[256];
-
-	/* Send QueryCancel if we are processing a database query */
-	if (cancelConn != NULL)
-	{
-		if (PQcancel(cancelConn, errbuf, sizeof(errbuf)))
-		{
-			CancelRequested = true;
-			fprintf(stderr, _("Cancel request sent\n"));
-		}
-		else
-			fprintf(stderr, _("Could not send cancel request: %s"), errbuf);
-	}
-	else
-		CancelRequested = true;
-
-	errno = save_errno;			/* just in case the write changed it */
-}
-
-void
-setup_cancel_handler(void)
-{
-	pqsignal(SIGINT, handle_sigint);
-}
-#else							/* WIN32 */
-
-/*
- * Console control handler for Win32. Note that the control handler will
- * execute on a *different thread* than the main one, so we need to do
- * proper locking around those structures.
- */
-static BOOL WINAPI
-consoleHandler(DWORD dwCtrlType)
-{
-	char		errbuf[256];
-
-	if (dwCtrlType == CTRL_C_EVENT ||
-		dwCtrlType == CTRL_BREAK_EVENT)
-	{
-		/* Send QueryCancel if we are processing a database query */
-		EnterCriticalSection(&cancelConnLock);
-		if (cancelConn != NULL)
-		{
-			if (PQcancel(cancelConn, errbuf, sizeof(errbuf)))
-			{
-				fprintf(stderr, _("Cancel request sent\n"));
-				CancelRequested = true;
-			}
-			else
-				fprintf(stderr, _("Could not send cancel request: %s"), errbuf);
-		}
-		else
-			CancelRequested = true;
-
-		LeaveCriticalSection(&cancelConnLock);
-
-		return TRUE;
-	}
-	else
-		/* Return FALSE for any signals not being handled */
-		return FALSE;
-}
-
-void
-setup_cancel_handler(void)
-{
-	InitializeCriticalSection(&cancelConnLock);
-
-	SetConsoleCtrlHandler(consoleHandler, TRUE);
-}
-
-#endif							/* WIN32 */