globpath refactor into pkg separate from filestat

internal/globpath/globpath.go

@@ -0,0 +1,93 @@
+package globpath
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/gobwas/glob"
+)
+
+var sepStr = fmt.Sprintf("%v", string(os.PathSeparator))
+
+type GlobPath struct {
+	path    string
+	hasMeta bool
+	g       glob.Glob
+	root    string
+}
+
+func Compile(path string) (*GlobPath, error) {
+	out := GlobPath{
+		hasMeta: hasMeta(path),
+		path:    path,
+	}
+
+	// if there are no glob meta characters in the path, don't bother compiling
+	// a glob object or finding the root directory. (see short-circuit in Match)
+	if !out.hasMeta {
+		return &out, nil
+	}
+
+	var err error
+	if out.g, err = glob.Compile(path, os.PathSeparator); err != nil {
+		return nil, err
+	}
+	// Get the root directory for this filepath
+	out.root = findRootDir(path)
+	return &out, nil
+}
+
+func (g *GlobPath) Match() []string {
+	if !g.hasMeta {
+		return []string{g.path}
+	}
+	return walkFilePath(g.root, g.g)
+}
+
+// walk the filepath from the given root and return a list of files that match
+// the given glob.
+func walkFilePath(root string, g glob.Glob) []string {
+	matchedFiles := []string{}
+	walkfn := func(path string, _ os.FileInfo, _ error) error {
+		if g.Match(path) {
+			matchedFiles = append(matchedFiles, path)
+		}
+		return nil
+	}
+	filepath.Walk(root, walkfn)
+	return matchedFiles
+}
+
+// find the root dir of the given path (could include globs).
+// ie:
+//   /var/log/telegraf.conf -> /var/log
+//   /home/** ->               /home
+//   /home/*/** ->             /home
+//   /lib/share/*/*/**.txt ->  /lib/share
+func findRootDir(path string) string {
+	pathItems := strings.Split(path, sepStr)
+	out := sepStr
+	for i, item := range pathItems {
+		if i == len(pathItems)-1 {
+			break
+		}
+		if item == "" {
+			continue
+		}
+		if hasMeta(item) {
+			break
+		}
+		out += item + sepStr
+	}
+	if out != "/" {
+		out = strings.TrimSuffix(out, "/")
+	}
+	return out
+}
+
+// hasMeta reports whether path contains any magic glob characters.
+func hasMeta(path string) bool {
+	return strings.IndexAny(path, "*?[") >= 0
+}

internal/globpath/globpath_test.go

@@ -0,0 +1,49 @@
+package globpath
+
+import (
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCompileAndMatch(t *testing.T) {
+	dir := getTestdataDir()
+	g1, err := Compile(dir + "/**")
+	require.NoError(t, err)
+	g2, err := Compile(dir + "/*.log")
+	require.NoError(t, err)
+	g3, err := Compile(dir + "/log1.log")
+	require.NoError(t, err)
+
+	matches := g1.Match()
+	assert.Len(t, matches, 3)
+	matches = g2.Match()
+	assert.Len(t, matches, 2)
+	matches = g3.Match()
+	assert.Len(t, matches, 1)
+}
+
+func TestFindRootDir(t *testing.T) {
+	tests := []struct {
+		input  string
+		output string
+	}{
+		{"/var/log/telegraf.conf", "/var/log"},
+		{"/home/**", "/home"},
+		{"/home/*/**", "/home"},
+		{"/lib/share/*/*/**.txt", "/lib/share"},
+	}
+
+	for _, test := range tests {
+		actual := findRootDir(test.input)
+		assert.Equal(t, test.output, actual)
+	}
+}
+
+func getTestdataDir() string {
+	_, filename, _, _ := runtime.Caller(1)
+	return strings.Replace(filename, "globpath_test.go", "testdata", 1)
+}

internal/globpath/testdata/test.conf

@@ -0,0 +1,5 @@
+# this is a fake testing config file
+# for testing the filestat plugin
+
+option1 = "foo"
+option2 = "bar"

plugins/inputs/filestat/filestat.go

@@ -5,17 +5,12 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"path/filepath"
-	"strings"
-
-	"github.com/gobwas/glob"
 
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal/globpath"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
 
-var sepStr = fmt.Sprintf("%v", string(os.PathSeparator))
-
 const sampleConfig = `
   ## Files to gather stats about.
   ## These accept standard unix glob matching rules, but with the addition of
@@ -29,16 +24,13 @@ type FileStat struct {
 	Md5   bool
 	Files []string
 
-	// maps full file paths to glob obj
-	globs map[string]glob.Glob
-	// maps full file paths to their root dir
-	roots map[string]string
+	// maps full file paths to globmatch obj
+	globs map[string]*globpath.GlobPath
 }
 
 func NewFileStat() *FileStat {
 	return &FileStat{
-		globs: make(map[string]glob.Glob),
-		roots: make(map[string]string),
+		globs: make(map[string]*globpath.GlobPath),
 	}
 }
 
@@ -56,27 +48,14 @@ func (f *FileStat) Gather(acc telegraf.Accumulator) error {
 		// Get the compiled glob object for this filepath
 		g, ok := f.globs[filepath]
 		if !ok {
-			if g, err = glob.Compile(filepath, os.PathSeparator); err != nil {
+			if g, err = globpath.Compile(filepath); err != nil {
 				errS += err.Error() + " "
 				continue
 			}
 			f.globs[filepath] = g
 		}
-		// Get the root directory for this filepath
-		root, ok := f.roots[filepath]
-		if !ok {
-			root = findRootDir(filepath)
-			f.roots[filepath] = root
-		}
 
-		var matches []string
-		// Do not walk file tree if we don't have to.
-		if !hasMeta(filepath) {
-			matches = []string{filepath}
-		} else {
-			matches = walkFilePath(f.roots[filepath], f.globs[filepath])
-		}
-		for _, file := range matches {
+		for _, file := range g.Match() {
 			tags := map[string]string{
 				"file": file,
 			}
@@ -118,20 +97,6 @@ func (f *FileStat) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-// walk the filepath from the given root and return a list of files that match
-// the given glob.
-func walkFilePath(root string, g glob.Glob) []string {
-	matchedFiles := []string{}
-	walkfn := func(path string, _ os.FileInfo, _ error) error {
-		if g.Match(path) {
-			matchedFiles = append(matchedFiles, path)
-		}
-		return nil
-	}
-	filepath.Walk(root, walkfn)
-	return matchedFiles
-}
-
 // Read given file and calculate an md5 hash.
 func getMd5(file string) (string, error) {
 	of, err := os.Open(file)
@@ -149,35 +114,6 @@ func getMd5(file string) (string, error) {
 	return fmt.Sprintf("%x", hash.Sum(nil)), nil
 }
 
-// find the root dir of the given path (could include globs).
-// ie:
-//   /var/log/telegraf.conf -> /var/log/
-//   /home/** ->               /home/
-//   /home/*/** ->             /home/
-//   /lib/share/*/*/**.txt ->  /lib/share/
-func findRootDir(path string) string {
-	pathItems := strings.Split(path, sepStr)
-	outpath := sepStr
-	for i, item := range pathItems {
-		if i == len(pathItems)-1 {
-			break
-		}
-		if item == "" {
-			continue
-		}
-		if hasMeta(item) {
-			break
-		}
-		outpath += item + sepStr
-	}
-	return outpath
-}
-
-// hasMeta reports whether path contains any magic glob characters.
-func hasMeta(path string) bool {
-	return strings.IndexAny(path, "*?[") >= 0
-}
-
 func init() {
 	inputs.Add("filestat", func() telegraf.Input {
 		return NewFileStat()

plugins/inputs/filestat/filestat_test.go

@@ -164,23 +164,6 @@ func TestGatherSuperAsterisk(t *testing.T) {
 	acc.AssertContainsTaggedFields(t, "filestat", fields3, tags3)
 }
 
-func TestFindRootDir(t *testing.T) {
-	tests := []struct {
-		input  string
-		output string
-	}{
-		{"/var/log/telegraf.conf", "/var/log/"},
-		{"/home/**", "/home/"},
-		{"/home/*/**", "/home/"},
-		{"/lib/share/*/*/**.txt", "/lib/share/"},
-	}
-
-	for _, test := range tests {
-		actual := findRootDir(test.input)
-		assert.Equal(t, test.output, actual)
-	}
-}
-
 func TestGetMd5(t *testing.T) {
 	dir := getTestdataDir()
 	md5, err := getMd5(dir + "test.conf")