Display timing/duration of evaluation

[Ville Misaki]

On Tue, Nov 10, 2015 at 6:03 AM, John Rose <john.r.rose at oracle.com> wrote:

> I'd prefer a threshold time:  If the execution takes less than the
> threshold, nothing is printed.
>

Great idea, and makes a lot of sense. I've updated my implementation to
include it (a new patch of the whole implementation attached).

The /timing now takes an optional parameter, using which you can set the
threshold to any non-negative value.

- Ville
-------------- next part --------------
# HG changeset patch
# Parent  ab33a84365a033fa30f1301eb85d80a2b6407ca7

diff -r ab33a84365a0 -r 89bbda0fdcfb src/jdk.jshell/share/classes/jdk/internal/jshell/tool/JShellTool.java
--- a/src/jdk.jshell/share/classes/jdk/internal/jshell/tool/JShellTool.java	Thu Nov 05 08:15:46 2015 -0800
+++ b/src/jdk.jshell/share/classes/jdk/internal/jshell/tool/JShellTool.java	Mon Nov 09 22:23:01 2015 +0900
@@ -42,6 +42,8 @@
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -141,6 +143,8 @@
 
     private boolean debug = false;
     private boolean displayPrompt = true;
+    private boolean displayTiming = false;
+    private double displayTimingThreshold = 5.0;
     public boolean testPrompt = false;
     private Feedback feedback = Feedback.Default;
     private String cmdlineClasspath = null;
@@ -462,12 +466,22 @@
                 if (!trimmed.isEmpty()) {
                     String line = incomplete + trimmed;
 
+                    Instant start = Instant.now();
+
                     // No commands in the middle of unprocessed source
                     if (incomplete.isEmpty() && line.startsWith("/") && !line.startsWith("//") && !line.startsWith("/*")) {
                         processCommand(line.trim());
                     } else {
                         incomplete = processSourceCatchingReset(line);
                     }
+
+                    if (in.interactiveOutput() && displayTiming) {
+                        double duration = 1.0 * Duration.between(start, Instant.now()).toMillis() / 1000;
+                        if (duration >= displayTimingThreshold) {
+                            fluff("Time elapsed: %.2fs\n", duration);
+                            concise("%.2fs\n", duration);
+                        }
+                    }
                 }
             }
         } catch (IOException ex) {
@@ -687,6 +701,9 @@
         registerCommand(new Command("/prompt", "/p", null, "toggle display of a prompt",
                                     arg -> cmdPrompt(),
                                     EMPTY_COMPLETION_PROVIDER));
+        registerCommand(new Command("/timing", null, "[threshold]", "toggle display of timing or set the threshold",
+                                    arg -> cmdTiming(arg),
+                                    EMPTY_COMPLETION_PROVIDER));
         registerCommand(new Command("/classpath", "/cp", "<path>", "add a path to the classpath",
                                     arg -> cmdClasspath(arg),
                                     classPathCompletion()));
@@ -1132,6 +1149,26 @@
         concise("Prompt: %s", displayPrompt ? "on" : "off");
     }
 
+    private void cmdTiming(String arg) {
+        if (arg == null || arg.isEmpty()) {
+            displayTiming = !displayTiming;
+        } else {
+            try {
+                double threshold = Double.parseDouble(arg);
+                if (threshold >= 0) {
+                    displayTiming = true;
+                    displayTimingThreshold = threshold;
+                } else {
+                    hard("Threshold value must be non-negative.");
+                }
+            } catch (NumberFormatException e) {
+                hard("Invalid threshold value: %s", arg);
+            }
+        }
+        fluff("Timing will %sdisplay. Threshold is %.2fs. Use /timing to toggle.", displayTiming ? "" : "NOT ", displayTimingThreshold);
+        concise("Timing: %s, %.2f", displayTiming ? "on" : "off", displayTimingThreshold);
+    }
+
     private void cmdReset() {
         live = false;
         fluff("Resetting state.");