From eb0e11c6611253038f235fb0376410895de8f249 Mon Sep 17 00:00:00 2001
From: Jehiah Czebotar <jehiah@gmail.com>
Date: Thu, 17 Jul 2014 08:13:47 -0400
Subject: [PATCH 1/3] convert sample to go

---
 sample/.gitignore |  1 +
 sample/main.go    | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 sample/.gitignore
 create mode 100644 sample/main.go

diff --git a/sample/.gitignore b/sample/.gitignore
new file mode 100644
index 0000000..d64a3d9
--- /dev/null
+++ b/sample/.gitignore
@@ -0,0 +1 @@
+sample
diff --git a/sample/main.go b/sample/main.go
new file mode 100644
index 0000000..86b6043
--- /dev/null
+++ b/sample/main.go
@@ -0,0 +1,37 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"math/rand"
+	"os"
+	"strconv"
+	"time"
+)
+
+func main() {
+
+	if len(os.Args) != 2 {
+		fmt.Fprintf(os.Stderr, "invalid argument. use a fraction to sample between 0.0 (no sampling) and 1.0 (100% sampling)")
+		os.Exit(1)
+	}
+
+	target, err := strconv.ParseFloat(os.Args[1], 64)
+	if err != nil || target < 0.0 || target > 1.0 {
+		fmt.Fprintf(os.Stderr, "Unable to convert %q to a float between 0.0 and 1.0", os.Args[1])
+		os.Exit(1)
+	}
+
+	rand.Seed(time.Now().UnixNano())
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		if target < rand.Float64() {
+			continue
+		}
+		fmt.Printf("%q", scanner.Text()) // Println will add back the final '\n'
+	}
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintln(os.Stderr, "reading standard input:", err)
+		os.Exit(2)
+	}
+}

From 12a0f28b2b1393a4c3012d8fca4a9f9a26882715 Mon Sep 17 00:00:00 2001
From: Jehiah Czebotar <jehiah@gmail.com>
Date: Thu, 17 Jul 2014 08:15:34 -0400
Subject: [PATCH 2/3] count output

---
 sample/main.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sample/main.go b/sample/main.go
index 86b6043..d9f2b68 100644
--- a/sample/main.go
+++ b/sample/main.go
@@ -10,7 +10,8 @@ import (
 )
 
 func main() {
-
+	var total int64
+	var emitted int64
 	if len(os.Args) != 2 {
 		fmt.Fprintf(os.Stderr, "invalid argument. use a fraction to sample between 0.0 (no sampling) and 1.0 (100% sampling)")
 		os.Exit(1)
@@ -25,13 +26,17 @@ func main() {
 	rand.Seed(time.Now().UnixNano())
 	scanner := bufio.NewScanner(os.Stdin)
 	for scanner.Scan() {
+		total += 1
 		if target < rand.Float64() {
 			continue
 		}
+		emitted += 1
 		fmt.Printf("%q", scanner.Text()) // Println will add back the final '\n'
 	}
 	if err := scanner.Err(); err != nil {
-		fmt.Fprintln(os.Stderr, "reading standard input:", err)
+		fmt.Fprintln(os.Stderr, "Error reading standard input:", err)
 		os.Exit(2)
 	}
+
+	fmt.Fprintf(os.Stderr, "Total of %d lines. Sampled to %d\n", total, emitted)
 }

From 7a468a9b743361595df58c31d6dc11736145f2e9 Mon Sep 17 00:00:00 2001
From: Jehiah Czebotar <jehiah@gmail.com>
Date: Thu, 17 Jul 2014 21:44:58 -0400
Subject: [PATCH 3/3] buffer and fix formatting

---
 sample/main.go | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/sample/main.go b/sample/main.go
index d9f2b68..069c499 100644
--- a/sample/main.go
+++ b/sample/main.go
@@ -23,6 +23,8 @@ func main() {
 		os.Exit(1)
 	}
 
+	out := bufio.NewWriterSize(os.Stdout, 1024*512)
+
 	rand.Seed(time.Now().UnixNano())
 	scanner := bufio.NewScanner(os.Stdin)
 	for scanner.Scan() {
@@ -31,12 +33,13 @@ func main() {
 			continue
 		}
 		emitted += 1
-		fmt.Printf("%q", scanner.Text()) // Println will add back the final '\n'
+		out.WriteString(scanner.Text())
+		out.WriteString("\n")
 	}
 	if err := scanner.Err(); err != nil {
 		fmt.Fprintln(os.Stderr, "Error reading standard input:", err)
 		os.Exit(2)
 	}
-
+	out.Flush()
 	fmt.Fprintf(os.Stderr, "Total of %d lines. Sampled to %d\n", total, emitted)
 }