add function fc_get_file_line_count_ex

HISTORY

@@ -1,5 +1,5 @@
 
-Version 1.44  2020-03-30
+Version 1.44  2020-03-31
   * add test file src/tests/test_pthread_lock.c
   * add uniq_skiplist.[hc]
   * add function split_string_ex
@@ -24,6 +24,7 @@ Version 1.44  2020-03-30
   * add function common_blocked_queue_return_nodes
   * add functions getIpAndPort and getPeerIpAndPort 
   * bugfixed: call fast_mblock_destroy in common_blocked_queue_destroy
+  * add function fc_get_file_line_count_ex
 
 Version 1.43  2019-12-25
   * replace function call system to getExecResult,

src/shared_func.c

@@ -693,6 +693,64 @@ int getOccurCount(const char *src, const char seperator)
 	return count;
 }
 
+int fc_get_file_line_count_ex(const char *filename,
+        const int64_t until_offset, int64_t *line_count)
+{
+#define READ_BUFFER_SIZE  (256 * 1024)
+    int fd;
+    int result;
+    int read_bytes;
+    int64_t remain_bytes;
+    char *buff;
+
+    *line_count = 0;
+    buff = (char *)malloc(READ_BUFFER_SIZE);
+    if (buff == NULL) {
+        logError("file: "__FILE__", line: %d, "
+                "malloc %d bytes fail",
+                __LINE__, READ_BUFFER_SIZE);
+        return ENOMEM;
+    }
+
+    fd = open(filename, O_RDONLY);
+    if (fd < 0) {
+        result = errno != 0 ? errno : EACCES;
+        logError("file: "__FILE__", line: %d, "
+                "open file \"%s\" fail, errno: %d, error info: %s",
+                __LINE__, filename, result, STRERROR(result));
+        free(buff);
+        return result;
+    }
+
+    if (until_offset >= 0) {
+        remain_bytes = until_offset;
+    } else {
+        remain_bytes = lseek(fd, 0, SEEK_END);
+    }
+    while (remain_bytes > 0) {
+        read_bytes = remain_bytes >= READ_BUFFER_SIZE ?
+            (READ_BUFFER_SIZE - 1) : remain_bytes;
+        read_bytes = read(fd, buff, read_bytes);
+        if (read_bytes == 0) {
+            break;
+        } else if (read_bytes < 0) {
+            result = errno != 0 ? errno : EIO;
+            logError("file: "__FILE__", line: %d, "
+                    "read file \"%s\" fail, errno: %d, error info: %s",
+                    __LINE__, filename, result, STRERROR(result));
+            return result;
+        }
+
+        *(buff + read_bytes) = '\0';
+        *line_count += getOccurCount(buff, '\n');
+        remain_bytes -= read_bytes;
+    }
+
+    close(fd);
+    free(buff);
+    return 0;
+}
+
 char **split(char *src, const char seperator, const int nMaxCols, int *nColCount)
 {
 	char **pCols;

src/shared_func.h

@@ -362,6 +362,24 @@ char *urldecode_ex(const char *src, const int src_len, char *dest, int *dest_len
 */
 int getOccurCount(const char *src, const char seperator);
 
+
+/** get the file line count
+ *  parameters:
+ *  	filename: the filename
+ *  	until_offset: util the file offset, -1 for file end
+ *  	line_count: store the line count
+ *  return: error no, 0 success, != 0 fail
+*/
+int fc_get_file_line_count_ex(const char *filename,
+        const int64_t until_offset, int64_t *line_count);
+
+static inline int fc_get_file_line_count(const char *filename,
+        int64_t *line_count)
+{
+    const int64_t until_offset = -1;
+    return fc_get_file_line_count_ex(filename, until_offset, line_count);
+}
+
 /** split string
  *  parameters:
  *  	src: the source string, will be modified by this function