add ini_parse_string_length() that avoids internal strlen(), and ease…

cpp/INIReader.cpp

@@ -24,8 +24,7 @@ INIReader::INIReader(const string& filename)
 
 INIReader::INIReader(const char *buffer, size_t buffer_size)
 {
-  string content(buffer, buffer_size);
-  _error = ini_parse_string(content.c_str(), ValueHandler, this);
+  _error = ini_parse_string_length(buffer, buffer_size, ValueHandler, this);
 }
 
 int INIReader::ParseError() const

ini.c

@@ -313,10 +313,16 @@ static char* ini_reader_string(char* str, int num, void* stream) {
 
 /* See documentation in header file. */
 int ini_parse_string(const char* string, ini_handler handler, void* user) {
+    return ini_parse_string_length(string, strlen(string), handler, user);
+}
+
+/* See documentation in header file. */
+int ini_parse_string_length(const char* string, size_t length,
+                            ini_handler handler, void* user) {
     ini_parse_string_ctx ctx;
 
     ctx.ptr = string;
-    ctx.num_left = strlen(string);
+    ctx.num_left = length;
     return ini_parse_stream((ini_reader)ini_reader_string, &ctx, handler,
                             user);
 }

ini.h

@@ -92,10 +92,15 @@ INI_API int ini_parse_stream(ini_reader reader, void* stream, ini_handler handle
                      void* user);
 
 /* Same as ini_parse(), but takes a zero-terminated string with the INI data
-instead of a file. Useful for parsing INI data from a network socket or
-already in memory. */
+   instead of a file. Useful for parsing INI data from a network socket or
+   which is already in memory. */
 INI_API int ini_parse_string(const char* string, ini_handler handler, void* user);
 
+/* Same as ini_parse_string(), but takes a string and its length, avoiding
+   strlen(). Useful for parsing INI data from a network socket or which is
+   already in memory, or interfacing with C++ std::string_view. */
+INI_API int ini_parse_string_length(const char* string, size_t length, ini_handler handler, void* user);
+
 /* Nonzero to allow multi-line value parsing, in the style of Python's
    configparser. If allowed, ini_parse() will call the handler with the same
    name for each subsequent line parsed. */