add native and cli approaches

compress/algorithm.go

@@ -3,14 +3,47 @@ package compress
 import (
 	"bytes"
 	"compress/gzip"
+	"fmt"
+	"os/exec"
 
 	"github.com/andybalholm/brotli"
 	"github.com/cdnjs/tools/util"
 )
 
-// Brotli11 returns a brotli compressed file as bytes
+// Runs an algorithm with a set of arguments,
+// and returns its stdout as bytes.
+// Note, this function will panic if anything is
+// output to stderr.
+func runAlgorithm(alg string, args ...string) []byte {
+	cmd := exec.Command(alg, args...)
+	var stdOut, stdErr bytes.Buffer
+	cmd.Stdout, cmd.Stderr = &stdOut, &stdErr
+
+	err := cmd.Run()
+	util.Check(err)
+
+	if stdErr.Len() > 0 {
+		panic(fmt.Sprintf("%s failed: %s", alg, stdErr.String()))
+	}
+
+	return stdOut.Bytes()
+}
+
+// Brotli11CLI returns a brotli compressed file as bytes
+// at optimal compression (quality 11).
+func Brotli11CLI(filePath string) []byte {
+	return runAlgorithm("brotli", "-c", "-q", "11", filePath)
+}
+
+// Gzip9CLI returns a gzip compressed file as bytes
+// at optimal compression (level 9).
+func Gzip9CLI(filePath string) []byte {
+	return runAlgorithm("gzip", "-c", "-9", filePath)
+}
+
+// Brotli11Native returns a brotli compressed file as bytes
 // at optimal compression (quality 11).
-func Brotli11(uncompressed []byte) []byte {
+func Brotli11Native(uncompressed []byte) []byte {
 	var b bytes.Buffer
 
 	w := brotli.NewWriterLevel(&b, brotli.BestCompression)
@@ -22,9 +55,9 @@ func Brotli11(uncompressed []byte) []byte {
 	return b.Bytes()
 }
 
-// Gzip9 returns a gzip compressed file as bytes
+// Gzip9Native returns a gzip compressed file as bytes
 // at optimal compression (level 9).
-func Gzip9(uncompressed []byte) []byte {
+func Gzip9Native(uncompressed []byte) []byte {
 	var b bytes.Buffer
 
 	w, err := gzip.NewWriterLevel(&b, gzip.BestCompression)