[Rd] Partial matching performance in data frame rownames using [

[Ivan Krylov]

В Mon, 11 Dec 2023 21:11:48 +0100
Hilmar Berger via R-devel <r-devel using r-project.org> пишет:

> What was unexpected is that in this case was that [.data.frame was
> hanging for a long time (I waited about 10 minutes and then restarted
> R). Also, this cannot be interrupted in interactive mode.

That's unfortunate. If an operation takes a long time, it ought to be
interruptible. Here's a patch that passes make check-devel:

--- src/main/unique.c	(revision 85667)
+++ src/main/unique.c	(working copy)
@@ -1631,6 +1631,7 @@
 	}
     }
 
+    unsigned int ic = 9999;
     if(nexact < n_input) {
 	/* Second pass, partial matching */
 	for (R_xlen_t i = 0; i < n_input; i++) {
@@ -1642,6 +1643,10 @@
 	    mtch = 0;
 	    mtch_count = 0;
 	    for (int j = 0; j < n_target; j++) {
+		if (!--ic) {
+		    R_CheckUserInterrupt();
+		    ic = 9999;
+		}
 		if (no_dups && used[j]) continue;
 		if (strncmp(ss, tar[j], temp) == 0) {
 		    mtch = j + 1;

-- 
Best regards,
Ivan