fix: display "N/A" as I/O timing values when track_io_timing is off and keep showing numeric values when it's on (#166)

Author: agneum

go.mod

@@ -3,6 +3,7 @@ module gitlab.com/postgres-ai/joe
 go 1.15
 
 require (
+	github.com/AlekSi/pointer v1.1.0
 	github.com/docker/docker v20.10.5+incompatible // indirect
 	github.com/dustin/go-humanize v1.0.0
 	github.com/hako/durafmt v0.0.0-20191009132224-3f39dc1ed9f4

pkg/pgexplain/pgexplain.go

@@ -73,8 +73,8 @@ type Explain struct {
 	TempWrittenBlocks   uint64
 
 	// IO timing.
-	IOReadTime  float64
-	IOWriteTime float64
+	IOReadTime  *float64
+	IOWriteTime *float64
 
 	ActualRows      uint64
 	MaxRows         uint64
@@ -104,8 +104,8 @@ type Plan struct {
 	TempWrittenBlocks   uint64 `json:"Temp Written Blocks"`
 
 	// IO timing.
-	IOReadTime  float64 `json:"I/O Read Time"`  // ms
-	IOWriteTime float64 `json:"I/O Write Time"` // ms
+	IOReadTime  *float64 `json:"I/O Read Time,omitempty"`  // ms
+	IOWriteTime *float64 `json:"I/O Write Time,omitempty"` // ms
 
 	// Actual.
 	ActualLoops       uint64  `json:"Actual Loops"`
@@ -449,15 +449,15 @@ func (ex *Explain) writeStatsText(writer io.Writer) {
 	fmt.Fprintf(writer, "  - execution: %s%s\n", util.MillisecondsToString(ex.ExecutionTime), ex.EstimationTime)
 
 	ioRead := util.NA
-	if ex.IOReadTime > 0 {
-		ioRead = util.MillisecondsToString(ex.IOReadTime)
+	if ex.IOReadTime != nil {
+		ioRead = util.MillisecondsToString(*ex.IOReadTime)
 	}
 
 	fmt.Fprintf(writer, "    - I/O read: %s\n", ioRead)
 
 	ioWrite := util.NA
-	if ex.IOWriteTime > 0 {
-		ioWrite = util.MillisecondsToString(ex.IOWriteTime)
+	if ex.IOWriteTime != nil {
+		ioWrite = util.MillisecondsToString(*ex.IOWriteTime)
 	}
 
 	fmt.Fprintf(writer, "    - I/O write: %s\n", ioWrite)
@@ -731,11 +731,12 @@ func writePlanTextNodeDetails(outputFn func(string, ...interface{}) (int, error)
 	}
 
 	ioTiming := ""
-	if plan.IOReadTime > 0 {
-		ioTiming += fmt.Sprintf(" read=%.3f", plan.IOReadTime)
+	if plan.IOReadTime != nil {
+		ioTiming += fmt.Sprintf(" read=%.3f", *plan.IOReadTime)
 	}
-	if plan.IOWriteTime > 0 {
-		ioTiming += fmt.Sprintf(" write=%.3f", plan.IOWriteTime)
+
+	if plan.IOWriteTime != nil {
+		ioTiming += fmt.Sprintf(" write=%.3f", *plan.IOWriteTime)
 	}
 
 	if len(ioTiming) > 0 {

pkg/pgexplain/pgexplain_test.go

@@ -8,6 +8,8 @@ import (
 	"bytes"
 	"testing"
 
+	"github.com/AlekSi/pointer"
+
 	"gitlab.com/postgres-ai/joe/pkg/util"
 
 	"github.com/sergi/go-diff/diffmatchpatch"
@@ -1857,8 +1859,6 @@ func TestStatsText(t *testing.T) {
 				TotalTime:      25,
 				PlanningTime:   3,
 				ExecutionTime:  22,
-				IOReadTime:     0,
-				IOWriteTime:    0,
 				EstimationTime: " (estimated* for prod: 0.0018...0.0021 s)",
 			},
 			expectedResult: `
@@ -1880,8 +1880,8 @@ Shared buffers:
 				TotalTime:     25,
 				PlanningTime:  3,
 				ExecutionTime: 22,
-				IOReadTime:    3,
-				IOWriteTime:   5,
+				IOReadTime:    pointer.ToFloat64(3),
+				IOWriteTime:   pointer.ToFloat64(5),
 			},
 			expectedResult: `
 Time: 25.000 ms
@@ -1890,6 +1890,28 @@ Time: 25.000 ms
     - I/O read: 3.000 ms
     - I/O write: 5.000 ms
 
+Shared buffers:
+  - hits: 0 from the buffer pool
+  - reads: 0 from the OS file cache, including disk I/O
+  - dirtied: 0
+  - writes: 0
+`,
+		},
+		{
+			explain: Explain{
+				TotalTime:     25,
+				PlanningTime:  3,
+				ExecutionTime: 22,
+				IOReadTime:    pointer.ToFloat64(0),
+				IOWriteTime:   pointer.ToFloat64(0),
+			},
+			expectedResult: `
+Time: 25.000 ms
+  - planning: 3.000 ms
+  - execution: 22.000 ms
+    - I/O read: 0.000 ms
+    - I/O write: 0.000 ms
+
 Shared buffers:
   - hits: 0 from the buffer pool
   - reads: 0 from the OS file cache, including disk I/O