Merge pull request #79 from yowcow/fix-findany-to-update-cur-prev-index

Update l.curindex/l.previndex at FindAny

.travis.yml

@@ -3,7 +3,7 @@ services:
 - docker
 language: go
 go:
-- 1.x
+- "1.10"
 addons:
   apt:
     packages:

loader/loader.go

@@ -54,24 +54,39 @@ func buildDirs(basedir string, count int) ([]string, error) {
 }
 
 // FindAny tries finding a file to load in any existing subdirectiries, and returns its filepath
-func (l Loader) FindAny() (string, bool) {
+func (l *Loader) FindAny() (string, bool) {
 	for i := 0; i < DirCount; i++ {
 		file := filepath.Join(l.dirs[i], l.filename)
 		if _, err := os.Stat(file); err == nil {
+			l.curindex = i
+			l.previndex = decrIndex(i)
 			return file, true
 		}
 	}
 	return "", false
 }
 
+func incrIndex(i int) int {
+	n := i + 1
+	if n >= DirCount {
+		return 0
+	}
+	return n
+}
+
+func decrIndex(i int) int {
+	n := i - 1
+	if n < 0 {
+		return DirCount - 1
+	}
+	return n
+}
+
 // DropIn drops given file into next subdirectory, and returns the filepath
 func (l *Loader) DropIn(file string) (string, error) {
 	defer syscall.Sync() // make sure write is in sync
 
-	nextindex := l.curindex + 1
-	if nextindex >= len(l.dirs) {
-		nextindex = 0
-	}
+	nextindex := incrIndex(l.curindex)
 	nextdir := l.dirs[nextindex]
 	nextfile := filepath.Join(nextdir, l.filename)
 	if err := os.Rename(file, nextfile); err != nil {

loader/loader_test.go

@@ -1,6 +1,7 @@
 package loader
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"testing"
@@ -74,30 +75,58 @@ func TestNew(t *testing.T) {
 }
 
 func TestFindAny(t *testing.T) {
-	dir := testutil.CreateTmpDir()
-	defer os.RemoveAll(dir)
+	type Case struct {
+		subtest           string
+		dirToCreateFile   string
+		expectedOK        bool
+		expectedPrevindex int
+		expectedCurindex  int
+	}
+	cases := []Case{
+		{
+			"no pre-existing file",
+			"",
+			false,
+			-1,
+			-1,
+		},
+		{
+			"pre-existing file in data00",
+			"data00",
+			true,
+			1,
+			0,
+		},
+		{
+			"pre-existing file in data01",
+			"data01",
+			true,
+			0,
+			1,
+		},
+	}
 
-	loader, _ := New(dir, "test.data")
-	file00 := filepath.Join(dir, "data00", "test.data")
-	file01 := filepath.Join(dir, "data01", "test.data")
+	for _, c := range cases {
+		t.Run(c.subtest, func(t *testing.T) {
+			dir := testutil.CreateTmpDir()
+			defer os.RemoveAll(dir)
 
-	{
-		_, ok := loader.FindAny()
-		assert.False(t, ok)
-	}
+			l, _ := New(dir, "test.data")
 
-	{
-		testutil.CopyFile(file01, "loader_test.go")
-		file, ok := loader.FindAny()
-		assert.True(t, ok)
-		assert.Equal(t, file01, file)
-	}
+			expectedFile := ""
+			if c.dirToCreateFile != "" {
+				expectedFile = filepath.Join(dir, c.dirToCreateFile, "test.data")
+				testutil.CopyFile(expectedFile, "loader_test.go")
+			}
+			fmt.Println(expectedFile)
 
-	{
-		testutil.CopyFile(file00, "loader_test.go")
-		file, ok := loader.FindAny()
-		assert.True(t, ok)
-		assert.Equal(t, file00, file)
+			file, ok := l.FindAny()
+
+			assert.Equal(t, c.expectedOK, ok)
+			assert.Equal(t, expectedFile, file)
+			assert.Equal(t, c.expectedPrevindex, l.previndex)
+			assert.Equal(t, c.expectedCurindex, l.curindex)
+		})
 	}
 }