gobench competition

gistfile1.go

// Package bench is a package which contains
// programs of Go Benchmark Competition.
package bench

import (
	"errors"
	"bufio"
	"os"
	"fmt"
	"bytes"
	"strconv"
)

func Find(path, s string) (string, error) {
	bS := []byte(s)
	if len(bS) == 0 {
		return "", errors.New("String cannot be empty");
	}

	file, err := os.Open(path)
	if err != nil {
		return "", err
	}

	scanner := bufio.NewScanner(file)

	i := 1
	buffer := make([]byte, 0, 16384)
	hasHit := false
	for scanner.Scan() {
		line := scanner.Bytes()
		offset := 0;
		for {
			index := bytes.Index(line[offset:], bS)
			if index >= 0 {
				offset += index
				if hasHit {
					buffer = append(buffer, 44)
				} else {
					hasHit = true
				}

				buffer = strconv.AppendInt(buffer, int64(i), 10)
				buffer = append(buffer, 58)
				buffer = strconv.AppendInt(buffer, int64(offset), 10)
				offset++
			} else {
				break;
			}
		}
		i += 1
	}

	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "Error reading file", err)
	}

	return string(buffer), nil
}