diff --git a/HISTORY b/HISTORY
index eaaaa9b..7b9a50f 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,5 +1,5 @@
 
-Version 1.54  2021-10-10
+Version 1.54  2021-10-19
   * fast_allocator.[hc]: correct reclaim_interval logic
   * shared_func.[hc]: add functions getFileContentEx1 and getFileContent1
   * fc_queue.[hc]: add function fc_queue_timedpeek
@@ -7,6 +7,7 @@ Version 1.54  2021-10-10
   * add files: sorted_queue.[hc]
   * add files: array_allocator.[hc]
   * add files: sorted_array.[hc]
+  * shared_func.[hc]: add function fc_read_lines
 
 Version 1.53  2021-06-30
   * process_action support action status
diff --git a/src/shared_func.c b/src/shared_func.c
index 52e0c88..3b3b085 100644
--- a/src/shared_func.c
+++ b/src/shared_func.c
@@ -1509,6 +1509,41 @@ int fd_gets(int fd, char *buff, const int size, int once_bytes)
 	return pDest - buff;
 }
 
+ssize_t fc_read_lines(int fd, char *buf, const size_t size)
+{
+    ssize_t count;
+    ssize_t old;
+    int remain;
+    char *last;
+
+    if ((count=fc_safe_read(fd, buf, size)) <= 0)
+    {
+        return count;
+    }
+
+    if ((last=(char *)fc_memrchr(buf, '\n', count)) == NULL)
+    {
+        last = buf;
+    }
+    else
+    {
+        last++;   //skip \n
+    }
+
+    old = count;
+    count = last - buf;
+    remain = old - count;
+    if (remain > 0)
+    {
+        if (lseek(fd, -1 * remain, SEEK_CUR) < 0)
+        {
+            return -1;
+        }
+    }
+
+    return count;
+}
+
 int set_rlimit(int resource, const rlim_t value)
 {
 	struct rlimit limit;
diff --git a/src/shared_func.h b/src/shared_func.h
index a53f4e4..a5818c7 100644
--- a/src/shared_func.h
+++ b/src/shared_func.h
@@ -880,6 +880,15 @@ ssize_t fc_lock_write(int fd, const char *buf, const size_t nbyte);
 */
 ssize_t fc_safe_read(int fd, char *buf, const size_t count);
 
+/** read integral lines from file
+ *  parameters:
+ *  	fd: the fd to read
+ *  	buf: the buffer to store the line
+ *  	size: max read bytes
+ *  return: error no , 0 success, != 0 fail
+*/
+ssize_t fc_read_lines(int fd, char *buf, const size_t size);
+
 /** ftok with hash code
  *  parameters:
  *  	path: the file path
diff --git a/src/uniq_skiplist.h b/src/uniq_skiplist.h
index d14ecc0..2bcbcd3 100644
--- a/src/uniq_skiplist.h
+++ b/src/uniq_skiplist.h
@@ -139,6 +139,24 @@ static inline int uniq_skiplist_init_pair_ex(UniqSkiplistPair *pair,
     return 0;
 }
 
+static inline UniqSkiplist *uniq_skiplist_new_by_pair(
+        UniqSkiplistPair *pair, const int level_count)
+{
+    if (pair->skiplist == NULL) {
+        pair->skiplist = uniq_skiplist_new(&pair->factory, level_count);
+    }
+
+    return pair->skiplist;
+}
+
+static inline void uniq_skiplist_free_by_pair(UniqSkiplistPair *pair)
+{
+    if (pair->skiplist != NULL) {
+        uniq_skiplist_free(pair->skiplist);
+        pair->skiplist = NULL;
+    }
+}
+
 int uniq_skiplist_insert(UniqSkiplist *sl, void *data);
 int uniq_skiplist_delete_ex(UniqSkiplist *sl, void *data,
         const bool need_free);