Change display to not show comments; fix quit handling

Showing the comments for settings lines typically is more confusing
than useful, so for simpler display we remove them.

This commit also fixes the handling of 'quit' when tuning settings
which was previously silently ignored.

pkg/tstune/tuner.go

@@ -124,32 +124,33 @@ func (t *Tuner) Run(flags *TunerFlags, in io.Reader, out io.Writer, outErr io.Wr
 		}
 	}
 
+	ifErrHandle := func(err error) {
+		if err != nil {
+			t.handler.errorExit(err)
+		}
+	}
+
 	// write backup
 
 	cfs, err := getConfigFileState(file)
-	if err != nil {
-		t.handler.errorExit(err)
-	}
+	ifErrHandle(err)
 	t.cfs = cfs
 
 	totalMemory := memory.TotalMemory()
 	cpus := runtime.NumCPU()
 
 	if t.flags.Quiet {
 		err = t.processQuiet(totalMemory, cpus)
-		if err != nil {
-			t.handler.errorExit(err)
-		}
+		ifErrHandle(err)
 	} else {
 		err = t.processSharedLibLine()
-		if err != nil {
-			t.handler.errorExit(err)
-		}
+		ifErrHandle(err)
 
 		printFn(os.Stderr, "\n")
 		err = t.promptUntilValidInput(promptTune+promptYesNo, newYesNoChecker(""))
 		if err == nil {
-			t.processTunables(totalMemory, cpus, false /* quiet */)
+			err = t.processTunables(totalMemory, cpus, false /* quiet */)
+			ifErrHandle(err)
 		} else if err.Error() != "" { // error msg of "" is response when user selects no to tuning
 			t.handler.errorExit(err)
 		}
@@ -170,9 +171,7 @@ func (t *Tuner) Run(flags *TunerFlags, in io.Reader, out io.Writer, outErr io.Wr
 			t.handler.exit(1, "could not open %s for writing: %v", outPath, err)
 		}
 		_, err = t.cfs.WriteTo(f)
-		if err != nil {
-			t.handler.errorExit(err)
-		}
+		ifErrHandle(err)
 	} else {
 		t.handler.p.Statement("Success, but not writing due to --dry-run flag")
 	}
@@ -289,22 +288,29 @@ func (t *Tuner) processSharedLibLine() error {
 		return t.processNoSharedLibLine()
 	}
 
-	sharedIdx := t.cfs.sharedLibResult.idx
-	newLine := updateSharedLibLine(t.cfs.lines[sharedIdx], t.cfs.sharedLibResult)
-	if newLine == t.cfs.lines[sharedIdx] { // already valid, nothing to do
+	res := t.cfs.sharedLibResult
+	idx := res.idx
+	newLine := updateSharedLibLine(t.cfs.lines[idx], res)
+	if newLine == t.cfs.lines[idx] { // already valid, nothing to do
 		t.handler.p.Success(successSharedLibCorrect)
 	} else {
 		t.handler.p.Statement("shared_preload_libraries needs to be updated")
 		t.handler.p.Statement(currentLabel)
-		printFn(t.handler.out, t.cfs.lines[sharedIdx]+"\n")
+		// want to print without trailing comments to reduce clutter
+		currWithoutComments := fmt.Sprintf("%sshared_preload_libraries = '%s'", res.commentGroup, res.libs)
+		printFn(t.handler.out, currWithoutComments+"\n")
+
 		t.handler.p.Statement(recommendLabel)
-		printFn(t.handler.out, newLine+"\n")
+		// want to print without trailing comments to reduce clutter
+		recWithoutComments := updateSharedLibLine(currWithoutComments, res)
+		printFn(t.handler.out, recWithoutComments+"\n")
+
 		checker := newYesNoChecker(errSharedLibNeeded)
 		err := t.promptUntilValidInput(promptOkay+promptYesNo, checker)
 		if err != nil {
 			return err
 		}
-		t.cfs.lines[sharedIdx] = newLine
+		t.cfs.lines[idx] = newLine // keep trailing comments when writing
 		t.handler.p.Success(successSharedLibUpdated)
 	}
 	return nil
@@ -403,15 +409,19 @@ func (t *Tuner) processSettingsGroup(sg pgtune.SettingsGroup, quiet bool) error
 					t.handler.p.Error("missing", r.key)
 					return
 				}
-				printFn(os.Stdout, t.cfs.lines[r.idx]+"\n")
+				format := fmtTunableParam
+				if r.commented {
+					format = "#" + format
+				}
+				printFn(os.Stdout, format, r.key, r.value, "") // don't print comment, too cluttered
 			})
 
 			// Now display recommendations, but only those with new recommendations
 			t.handler.p.Statement(recommendLabel)
 		}
 		// Recommendations are always displayed, but the label above may not be
 		doWithVisibile(func(r *tunableParseResult) {
-			printFn(os.Stdout, fmtTunableParam, r.key, recommender.Recommend(r.key), r.extra)
+			printFn(os.Stdout, fmtTunableParam, r.key, recommender.Recommend(r.key), "") // don't print comment, too cluttered
 		})
 
 		// Prompt the user for input (only in non-quiet mode)
@@ -429,7 +439,7 @@ func (t *Tuner) processSettingsGroup(sg pgtune.SettingsGroup, quiet bool) error
 
 		// If we reach here, it means the user accepted our recommendations, so update the lines
 		doWithVisibile(func(r *tunableParseResult) {
-			newLine := fmt.Sprintf(fmtTunableParam, r.key, recommender.Recommend(r.key), r.extra)
+			newLine := fmt.Sprintf(fmtTunableParam, r.key, recommender.Recommend(r.key), r.extra) // do write comment into file
 			if r.idx == -1 {
 				t.cfs.lines = append(t.cfs.lines, newLine)
 			} else {
@@ -487,7 +497,7 @@ func (t *Tuner) processQuiet(totalMemory uint64, cpus int) error {
 		}
 	}
 
-	t.processTunables(totalMemory, cpus, true /* quiet */)
+	_ = t.processTunables(totalMemory, cpus, true /* quiet */)
 	checker := newYesNoChecker("not using these settings could lead to suboptimal performance")
 	err := t.promptUntilValidInput("Use these recommendations? "+promptYesNo, checker)
 	if err != nil {

pkg/tstune/tuner_test.go

@@ -395,6 +395,7 @@ func TestProcessNoSharedLibLine(t *testing.T) {
 
 func TestProcessSharedLibLine(t *testing.T) {
 	okLine := "shared_preload_libraries = 'timescaledb' # (need restart)"
+	okLinePrint := "shared_preload_libraries = 'timescaledb'"
 	cases := []struct {
 		desc       string
 		lines      []string
@@ -421,17 +422,17 @@ func TestProcessSharedLibLine(t *testing.T) {
 			shouldErr:  false,
 			prompts:    1,
 			statements: 3,
-			prints:     []string{"#" + okLine + "\n", okLine + "\n"},
+			prints:     []string{"#" + okLinePrint + "\n", okLinePrint + "\n"},
 			successMsg: successSharedLibUpdated,
 		},
 		{
 			desc:       "success on 2nd prompt",
-			lines:      []string{"#" + okLine},
+			lines:      []string{"  ##  " + okLine},
 			input:      " \ny\n",
 			shouldErr:  false,
 			prompts:    2,
 			statements: 3,
-			prints:     []string{"#" + okLine + "\n", okLine + "\n"},
+			prints:     []string{"##  " + okLinePrint + "\n", okLinePrint + "\n"},
 			successMsg: successSharedLibUpdated,
 		},
 		{
@@ -441,7 +442,7 @@ func TestProcessSharedLibLine(t *testing.T) {
 			shouldErr:  true,
 			prompts:    2,
 			statements: 3,
-			prints:     []string{"#" + okLine + "\n", okLine + "\n"},
+			prints:     []string{"#" + okLinePrint + "\n", okLinePrint + "\n"},
 			successMsg: "",
 		},
 		{