add skip support for list of commented posts

README.md

@@ -190,7 +190,7 @@ Sort can be `time` or `score`. Supported sort order with prefix -/+, i.e. `-time
     }{}
     ```
 - `GET /api/v1/count?site=site-id&url=post-url` - get comment's count for `{url}`
-- `GET /api/v1/list?site=site-id&limit=5` - list commented posts, returns array or `PostInfo`, limit=0 will return all posts
+- `GET /api/v1/list?site=site-id&limit=5&skip=2` - list commented posts, returns array or `PostInfo`, limit=0 will return all posts
     ```go
     type PostInfo struct {
         URL   string `json:"url"`

app/migrator/remark.go

@@ -19,7 +19,7 @@ type Remark struct {
 
 // Export all comments to writer as json strings. Each comment is one string, separated by "\n"
 func (r *Remark) Export(w io.Writer, siteID string) error {
-	topics, err := r.DataStore.List(siteID, 0)
+	topics, err := r.DataStore.List(siteID, 0, 0)
 	if err != nil {
 		return err
 	}

app/rest/api/rest.go

@@ -375,18 +375,21 @@ func (s *Rest) countCtrl(w http.ResponseWriter, r *http.Request) {
 	render.JSON(w, r, JSON{"count": count, "locator": locator})
 }
 
-// GET /list?site=siteID&limit=50 - list posts with comments
+// GET /list?site=siteID&limit=50&skip=10 - list posts with comments
 func (s *Rest) listCtrl(w http.ResponseWriter, r *http.Request) {
 
 	siteID := r.URL.Query().Get("site")
-	limit := 0
-	limitStr := r.URL.Query().Get("limit")
-	if v, err := strconv.Atoi(limitStr); err == nil {
+	limit, skip := 0, 0
+
+	if v, err := strconv.Atoi(r.URL.Query().Get("limit")); err == nil {
 		limit = v
 	}
+	if v, err := strconv.Atoi(r.URL.Query().Get("skip")); err == nil {
+		skip = v
+	}
 
 	data, err := s.Cache.Get(rest.URLKey(r), 8*time.Hour, func() ([]byte, error) {
-		posts, e := s.DataService.List(siteID, limit)
+		posts, e := s.DataService.List(siteID, limit, skip)
 		if e != nil {
 			return nil, e
 		}

app/store/bolt.go

@@ -340,7 +340,7 @@ func (b *BoltDB) Blocked(siteID string) (users []BlockedUser, err error) {
 
 // List returns list of all commented posts with counters
 // uses count bucket to get number of comments
-func (b BoltDB) List(siteID string, limit int) (list []PostInfo, err error) {
+func (b BoltDB) List(siteID string, limit, skip int) (list []PostInfo, err error) {
 
 	bdb, err := b.db(siteID)
 	if err != nil {
@@ -351,7 +351,12 @@ func (b BoltDB) List(siteID string, limit int) (list []PostInfo, err error) {
 		postsBkt := tx.Bucket([]byte(postsBucketName))
 
 		c := postsBkt.Cursor()
+		n := 0
 		for k, _ := c.Last(); k != nil; k, _ = c.Prev() {
+			n++
+			if skip > 0 && n <= skip {
+				continue
+			}
 			postURL := string(k)
 			count, e := b.count(tx, postURL, 0)
 			if e != nil {
@@ -361,6 +366,7 @@ func (b BoltDB) List(siteID string, limit int) (list []PostInfo, err error) {
 			if limit > 0 && len(list) >= limit {
 				break
 			}
+
 		}
 		return nil
 	})

app/store/bolt_test.go

@@ -160,13 +160,17 @@ func TestBoltDB_List(t *testing.T) {
 	_, err := b.Create(comment)
 	assert.Nil(t, err)
 
-	res, err := b.List("radio-t", 0)
+	res, err := b.List("radio-t", 0, 0)
 	assert.Nil(t, err)
 	assert.Equal(t, []PostInfo{{URL: "https://radio-t.com/2", Count: 1}, {URL: "https://radio-t.com", Count: 2}}, res)
 
-	res, err = b.List("radio-t", 1)
+	res, err = b.List("radio-t", 1, 0)
 	assert.Nil(t, err)
 	assert.Equal(t, []PostInfo{{URL: "https://radio-t.com/2", Count: 1}}, res)
+
+	res, err = b.List("radio-t", 1, 1)
+	assert.Nil(t, err)
+	assert.Equal(t, []PostInfo{{URL: "https://radio-t.com", Count: 2}}, res)
 }
 
 func TestBoltDB_GetForUser(t *testing.T) {

app/store/store.go

@@ -22,7 +22,7 @@ type Accessor interface {
 	Last(siteID string, max int) ([]Comment, error)                     // last comments for given site, sorted by time
 	User(siteID string, userID string) ([]Comment, int, error)          // comments by user, sorted by time
 	Count(locator Locator) (int, error)                                 // number of comments for the post
-	List(siteID string, limit int) ([]PostInfo, error)                  // list of commented posts
+	List(siteID string, limit int, skip int) ([]PostInfo, error)                  // list of commented posts
 }
 
 // Admin defines all store ops avail for admin only

remark.rest

@@ -63,7 +63,7 @@ GET {{host}}/api/v1/comments?site=remark&user=disqus_umputun
 GET {{host}}/api/v1/count?site=remark&url=https://radio-t.com/p/2017/12/16/podcast-576/
 
 ### list commented posts
-GET {{host}}/api/v1/list?site=remark
+GET {{host}}/api/v1/list?site=remark&limit=10&skip=5
 
 ### get config
 GET {{host}}/api/v1/config