split and replace store component

internal/filestore/channel.go

@@ -0,0 +1,151 @@
+package filestore
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"sort"
+	"sync"
+
+	"github.com/vim-jp/slacklog-generator/internal/store"
+)
+
+type channelStore struct {
+	dir string
+
+	rw       sync.RWMutex
+	channels []store.Channel
+	idxID    map[string]int
+}
+
+// Get gets a channel by ID.
+func (cs *channelStore) Get(id string) (*store.Channel, error) {
+	err := cs.assureLoad()
+	if err != nil {
+		return nil, err
+	}
+	cs.rw.RLock()
+	defer cs.rw.RUnlock()
+
+	x, ok := cs.idxID[id]
+	if !ok {
+		return nil, fmt.Errorf("channel not found, uknown id: id=%s", id)
+	}
+	if x < 0 || x >= len(cs.channels) {
+		return nil, fmt.Errorf("channel index collapsed, ask developers: id=%s", id)
+	}
+	c := cs.channels[x]
+	return &c, nil
+}
+
+// Iterate enumerates all channels by callback.
+// 呼び出し時点でチャンネル一覧のコピーが本イテレート専用に作成される。
+// コールバックが false を返すと store.ErrIterateAbort が返る
+func (cs *channelStore) Iterate(iter store.ChannelIterator) error {
+	err := cs.assureLoad()
+	if err != nil {
+		return err
+	}
+	cs.rw.RLock()
+	channels := make([]store.Channel, len(cs.channels))
+	copy(channels, cs.channels)
+	// FIXME: cs.idxID に入ってないのは省くべきでは?
+	cs.rw.RUnlock()
+	for i := range channels {
+		cont := iter.Iterate(&channels[i])
+		if !cont {
+			return store.ErrIterateAbort
+		}
+	}
+	return nil
+}
+
+// Upsert updates or inserts a channel in store.
+// This returns true as 1st parameter, when a channel inserted.
+func (cs *channelStore) Upsert(c store.Channel) (bool, error) {
+	if c.ID == "" {
+		return false, errors.New("empty ID is forbidden")
+	}
+
+	err := cs.assureLoad()
+	if err != nil {
+		return false, err
+	}
+	cs.rw.Lock()
+	defer cs.rw.Unlock()
+
+	c.Tidy()
+
+	x, ok := cs.idxID[c.ID]
+	if ok {
+		cs.channels[x] = c
+		return true, nil
+	}
+	cs.idxID[c.ID] = len(cs.channels)
+	cs.channels = append(cs.channels, c)
+	return false, nil
+}
+
+// Commit saves channels to file:channels.json.
+func (cs *channelStore) Commit() error {
+	cs.rw.Lock()
+	defer cs.rw.Unlock()
+	if cs.channels == nil {
+		log.Printf("[DEBUG] no channels to commit. not load yet?")
+		return nil
+	}
+
+	ids := make([]string, 0, len(cs.idxID))
+	for id := range cs.idxID {
+		ids = append(ids, id)
+	}
+	sort.Strings(ids)
+	ca := make([]store.Channel, len(ids))
+	for i, id := range ids {
+		ca[i] = cs.channels[cs.idxID[id]]
+	}
+	err := jsonWriteFile(cs.path(), ca)
+	if err != nil {
+		return err
+	}
+
+	cs.replaceChannels(ca)
+	return nil
+}
+
+// path returns path for channels.json
+func (cs *channelStore) path() string {
+	return filepath.Join(cs.dir, "channels.json")
+}
+
+// assureLoad assure channels.json is loaded.
+func (cs *channelStore) assureLoad() error {
+	cs.rw.Lock()
+	defer cs.rw.Unlock()
+	if cs.channels != nil {
+		return nil
+	}
+	var channels []store.Channel
+	err := jsonReadFile(cs.path(), true, &channels)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	cs.replaceChannels(channels)
+	return nil
+}
+
+func (cs *channelStore) replaceChannels(channels []store.Channel) {
+	if len(channels) == 0 {
+		cs.channels = []store.Channel{}
+		cs.idxID = map[string]int{}
+		return
+	}
+	idxID := make(map[string]int, len(channels))
+	for i, c := range channels {
+		idxID[c.ID] = i
+	}
+	cs.channels = channels
+	cs.idxID = idxID
+}

internal/filestore/channel_test.go

@@ -0,0 +1,167 @@
+package filestore
+
+import (
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/vim-jp/slacklog-generator/internal/store"
+	"github.com/vim-jp/slacklog-generator/internal/testassert"
+)
+
+func jsonToChannel(t *testing.T, s string) *store.Channel {
+	t.Helper()
+	var c store.Channel
+	err := json.Unmarshal([]byte(s), &c)
+	if err != nil {
+		t.Fatalf("failed to parse as Channel: %s", err)
+	}
+	return &c
+}
+
+func TestChannelStore_Get(t *testing.T) {
+	cs := &channelStore{dir: "testdata/channel_read"}
+
+	for _, tc := range []struct {
+		id  string
+		exp string
+	}{
+		{"CXXXX0001", `{"id":"CXXXX0001","name":"channel01"}`},
+		{"CXXXX0002", `{"id":"CXXXX0002","name":"channel02"}`},
+		{"CXXXX0003", `{"id":"CXXXX0003","name":"channel03"}`},
+		{"CXXXX0004", `{"id":"CXXXX0004","name":"channel04"}`},
+		{"CXXXX0005", `{"id":"CXXXX0005","name":"channel05"}`},
+	} {
+		act, err := cs.Get(tc.id)
+		if err != nil {
+			t.Fatalf("failed to get(%s): %s", tc.id, err)
+		}
+		exp := jsonToChannel(t, tc.exp)
+		testassert.Equal(t, exp, act, "id:"+tc.id)
+	}
+
+	c, err := cs.Get("CXXXX9999")
+	if err == nil {
+		t.Fatalf("should fail to get unknown ID: %+v", c)
+	}
+	if !strings.HasPrefix(err.Error(), "channel not found, ") {
+		t.Fatalf("unexpected error for getting unknown ID: %s", err)
+	}
+}
+
+func TestChannelStore_Iterate(t *testing.T) {
+	cs := &channelStore{dir: "testdata/channel_read"}
+
+	var act []*store.Channel
+	err := cs.Iterate(store.ChannelIterateFunc(func(c *store.Channel) bool {
+		act = append(act, c)
+		return true
+	}))
+	if err != nil {
+		t.Fatalf("iteration failed: %s", err)
+	}
+	exp := []*store.Channel{
+		jsonToChannel(t, `{"id":"CXXXX0001","name":"channel01"}`),
+		jsonToChannel(t, `{"id":"CXXXX0002","name":"channel02"}`),
+		jsonToChannel(t, `{"id":"CXXXX0003","name":"channel03"}`),
+		jsonToChannel(t, `{"id":"CXXXX0004","name":"channel04"}`),
+		jsonToChannel(t, `{"id":"CXXXX0005","name":"channel05"}`),
+	}
+	testassert.Equal(t, exp, act, "simple iteration")
+}
+
+func TestChannelStore_Iterate_Break(t *testing.T) {
+	cs := &channelStore{dir: "testdata/channel_read"}
+
+	i := 0
+	err := cs.Iterate(store.ChannelIterateFunc(func(_ *store.Channel) bool {
+		i++
+		return i > 2
+	}))
+	if !errors.Is(err, store.ErrIterateAbort) {
+		t.Fatalf("iterate should be failed with:%s got:%s", store.ErrIterateAbort, err)
+	}
+}
+
+func TestChannelStore_Write(t *testing.T) {
+	dir, err := ioutil.TempDir("testdata", "channel_write*")
+	if err != nil {
+		t.Fatalf("failed to TempDir: %s", err)
+	}
+	t.Cleanup(func() {
+		os.RemoveAll(dir)
+	})
+	cs := &channelStore{dir: dir}
+
+	for i, s := range []string{
+		`{"id":"W0001","name":"channel01"}`,
+		`{"id":"W0009","name":"channel09"}`,
+		`{"id":"W0005","name":"channel05"}`,
+		`{"id":"W0001","name":"channel01a"}`,
+	} {
+		_, err := cs.Upsert(*jsonToChannel(t, s))
+		if err != nil {
+			t.Fatalf("upsert failed #%d: %s", i, err)
+		}
+	}
+	err = cs.Commit()
+	if err != nil {
+		t.Fatalf("commit failed: %s", err)
+	}
+
+	cs2 := &channelStore{dir: dir}
+	err = cs2.assureLoad()
+	if err != nil {
+		t.Fatalf("assureLoad failed: %s", err)
+	}
+	testassert.Equal(t, []store.Channel{
+		*jsonToChannel(t, `{"id":"W0001","name":"channel01a"}`),
+		*jsonToChannel(t, `{"id":"W0005","name":"channel05"}`),
+		*jsonToChannel(t, `{"id":"W0009","name":"channel09"}`),
+	}, cs2.channels, "wrote channels.json")
+}
+
+func TestChannelStore_Upsert_NoID(t *testing.T) {
+	dir, err := ioutil.TempDir("testdata", "channel_write*")
+	if err != nil {
+		t.Fatalf("failed to TempDir: %s", err)
+	}
+	t.Cleanup(func() {
+		os.RemoveAll(dir)
+	})
+	cs := &channelStore{dir: dir}
+	_, err = cs.Upsert(*jsonToChannel(t, `{"name":"foobar"}`))
+	if err == nil {
+		t.Fatal("upsert without ID should be failed")
+	}
+	if err.Error() != "empty ID is forbidden" {
+		t.Fatalf("unexpected failure: %s", err)
+	}
+}
+
+func TestChannelStore_Commit_Empty(t *testing.T) {
+	// 空のCommitは channels.json を作らない
+	dir, err := ioutil.TempDir("testdata", "channel_write*")
+	if err != nil {
+		t.Fatalf("failed to TempDir: %s", err)
+	}
+	t.Cleanup(func() {
+		os.RemoveAll(dir)
+	})
+	cs := &channelStore{dir: dir}
+
+	err = cs.Commit()
+	if err != nil {
+		t.Fatalf("unexpted failure: %s", err)
+	}
+	fi, err := os.Stat(cs.path())
+	if err == nil {
+		t.Fatalf("channels.json created unexpectedly: %s", fi.Name())
+	}
+	if !os.IsNotExist(err) {
+		t.Fatalf("unexpected failure: %s", err)
+	}
+}