03. Word Count profile and add buffering part two

wordcount/README.md

@@ -8,8 +8,24 @@ A simple timer has been used to track execution time.
 
 Provide the name of the text file as a command line argument.
 
-`go run main.go moby.txt`  
+`go run main.go shakespeare.txt`  
 
 Example file to use:
-https://www.gutenberg.org/cache/epub/2701/pg2701.txt
+https://www.gutenberg.org/ebooks/100
 
+
+# Execution time
+
+For base branch:
+`"shakespeare.txt": 741200 words, duration: 3422897ms`
+
+For the profile branch with buffering:
+`"shakespeare.txt": 741200 words, duration: 97406ms`
+
+For this branch with global buffer:
+`"shakespeare.txt": 741200 words, duration: 67800ms`
+
+
+# To view profile
+
+`go tool pprof -http=:8080 cpuprofile.pprof`  

wordcount/main.go

@@ -1,16 +1,20 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
 	"io"
 	"log"
 	"os"
+	"runtime/pprof"
 	"time"
 	"unicode"
 )
 
+var buf [1]byte
+
 func readbyte(r io.Reader) (rune, error) {
-	var buf [1]byte
+
 	_, err := r.Read(buf[:])
 	return rune(buf[0]), err
 }
@@ -21,11 +25,19 @@ func main() {
 		log.Fatalf("could not open file %q: %v", os.Args[1], err)
 	}
 
+	fc, err := os.Create("cpuprofile.pprof")
+	if err != nil {
+		log.Fatal(err)
+	}
+	pprof.StartCPUProfile(fc)
+	defer pprof.StopCPUProfile()
+
 	start := time.Now()
 	words := 0
+	b := bufio.NewReader(f)
 	inword := false
 	for {
-		r, err := readbyte(f)
+		r, err := readbyte(b)
 		if err == io.EOF {
 			break
 		}