rework logging to not require C variadics

CMakeLists.txt

@@ -52,11 +52,11 @@ if (USE_SDL2)
 endif()
 
 if (BUILD_STATIC)
-    add_library(zhban_s STATIC zhban.c utf.c logging.c)
+    add_library(zhban_s STATIC zhban.c utf.c)
     install(TARGETS zhban_s ARCHIVE DESTINATION lib)
 endif()
 
-add_library(zhban SHARED zhban.c utf.c logging.c)
+add_library(zhban SHARED zhban.c utf.c)
 target_link_libraries(zhban ${PKG_HBZ_LIBRARIES} ${PKG_FT2_LIBRARIES})
 if (USE_SDL2)
     target_link_libraries(zhban ${PKG_SDL2_LIBRARIES})

python/zhban/__init__.py

@@ -174,17 +174,32 @@ def bind(libpath = None):
 class ZhbanFail(Exception):
     pass
 
+_LOG_SINK_ADAPTER = ctypes.CFUNCTYPE(None, ctypes.c_uint32, ctypes.c_char_p, ctypes.c_uint32)
+
 class Zhban(object):
-    def __init__(self, fontbuf, pixheight, subpix = True, loglevel = 0,
+    LOG_LEVEL = ( "null", "fatal", "error", "warn ", "info ", "trace" )
+
+    def _log_sink_adapter(self, level, buf, buflen):
+        msg = ctypes.string_at(buf, buflen).decode("utf-8")
+        if self.logsink is None:
+            sys.stderr.write("[{}] {}\n".format(self.LOG_LEVEL[level], msg))
+        else:
+            self.logsink(self, level, msg)
+
+    def __init__(self, fontbuf, pixheight, subpix = True, loglevel = 0, logsink = None,
                 gllim = 1<<20, szlim = 1<<16, rrlim = 1<<22, libpath = None):
         if type(fontbuf) is bytes:
             self._fbuf = fontbuf
         else:
             self._fbuf = bytes(fontbuf) # have to copy it.
         self._lib = bind(libpath)
         sp = 1 if subpix else 0
+
+        self.logsink = logsink
+
         self._z = self._lib.zhban_open(self._fbuf, len(self._fbuf), pixheight,
-                                            sp, gllim, szlim, rrlim, loglevel, 0)
+                                            sp, gllim, szlim, rrlim, loglevel,
+                                            _LOG_SINK_ADAPTER(self._log_sink_adapter))
         if not bool(self._z):
             raise ZhbanFail
 

python/zhban/test.py

@@ -226,7 +226,10 @@ def main():
     if not pa.font:
         ap.error("Font is required.")
 
-    zhban = Zhban(open(pa.font, "rb").read(), pa.size, loglevel=pa.l, subpix=pa.sp,
+    def log_sink(z, ll, msg):
+        print("custom_log_sink: [{}] {}".format(z.LOG_LEVEL[ll], msg))
+
+    zhban = Zhban(open(pa.font, "rb").read(), pa.size, loglevel=pa.l, subpix=pa.sp, logsink = log_sink,
                             libpath = os.environ.get('PYSDL2_DLL_PATH'))
 
     zhban.set_script(pa.dir, pa.script, pa.lang)

zhban.c

@@ -25,7 +25,6 @@
 #include <stddef.h>
 
 #include "zhban.h"
-#include "zhban-internal.h"
 
 #include <uthash.h>
 #include <utlist.h>
@@ -51,6 +50,14 @@ typedef uint32_t refcount_t;
 # define ZHBAN_GETREF(rc) ((rc))
 #endif
 
+#if defined(__GNUC__) || defined(__clang__)
+# define ATTR_UNUSED __attribute__((unused))
+#else
+# define ATTR_UNUSED
+#endif
+
+#define LOG_BUFFER_LEN 1024
+
 //{ context
 
 typedef struct _shape shape_t;
@@ -66,7 +73,8 @@ typedef struct _zhban_internal {
     zhban_t outer;
 
     int32_t   log_level;
-    logsink_t log_sink;
+    zhban_logsink_t log_sink;
+    char log_buffer[LOG_BUFFER_LEN];
 
     uint32_t pixheight;
     uint32_t subpixel_positioning;  /* cache translated glyphs */
@@ -98,6 +106,35 @@ typedef struct _zhban_internal {
 
 } zhban_internal_t;
 
+//{ logging
+
+static void logrintf(int msg_level, zhban_internal_t *z, const char *fmt, ...) {
+    int written = 0;
+    if (msg_level <= z->log_level) {
+        va_list ap;
+        va_start(ap, fmt);
+        written = vsnprintf(z->log_buffer, LOG_BUFFER_LEN, fmt, ap);
+        va_end(ap);
+        z->log_sink(msg_level, z->log_buffer, written);
+    }
+    if (msg_level == ZHLOG_FATAL)
+        abort();
+}
+
+#define log_trace(obj, fmt, args...) do { logrintf(ZHLOG_TRACE, obj, "%s(): " fmt, __func__, ## args); } while(0)
+#define log_info(obj, fmt, args...)  do { logrintf(ZHLOG_INFO,  obj, "%s(): " fmt, __func__, ## args); } while(0)
+#define log_warn(obj, fmt, args...)  do { logrintf(ZHLOG_WARN,  obj, "%s(): " fmt, __func__, ## args); } while(0)
+#define log_error(obj, fmt, args...) do { logrintf(ZHLOG_ERROR, obj, "%s(): " fmt, __func__, ## args); } while(0)
+#define log_fatal(obj, fmt, args...) do { logrintf(ZHLOG_FATAL, obj, "%s(): " fmt, __func__, ## args); } while(0)
+
+const char *log_level_name[] = { "null", "fatal", "error", "warn ", "info ", "trace" };
+
+static void logsink_stderr(const int level, const char *buf, const uint32_t len ATTR_UNUSED) {
+    fprintf(stderr, "[%s] %s\n", log_level_name[level], buf);
+}
+
+//}
+
 static int force_ucs2_charmap(FT_Face ftf) {
     for(int i = 0; i < ftf->num_charmaps; i++)
         if ((  (ftf->charmaps[i]->platform_id == 0)
@@ -111,7 +148,7 @@ static int force_ucs2_charmap(FT_Face ftf) {
 zhban_t *zhban_open(const void *data, const uint32_t datalen, uint32_t pixheight,
                                         uint32_t subpx,
                                         uint32_t glyphlimit, uint32_t shaperlimit, uint32_t renderlimit,
-                                        int32_t loglevel, logsink_t logsink) {
+                                        int32_t loglevel, zhban_logsink_t logsink) {
 
     zhban_internal_t *rv = malloc(sizeof(zhban_internal_t));
     if (!rv)
@@ -123,7 +160,7 @@ zhban_t *zhban_open(const void *data, const uint32_t datalen, uint32_t pixheight
     rv->outer.bitmap_limit = renderlimit;
 
     rv->log_level = loglevel;
-    rv->log_sink  = logsink ? logsink : printfsink;
+    rv->log_sink  = logsink ? logsink : logsink_stderr;
 
     if ((rv->ft_err = FT_Init_FreeType(&rv->ft_lib)))
         goto error;

zhban.h

@@ -107,7 +107,7 @@ typedef struct _zhban_bitmap {
 #define ZHLOG_ERROR 2
 #define ZHLOG_FATAL 1
 
-typedef void (*logsink_t)(const int level, const char *fmt, va_list ap);
+typedef void (*zhban_logsink_t)(const int level, const char *buffer, const uint32_t len);
 
 /* prepare to use a font face that FreeType2 can handle.
     data, size - buffer with the font data (must not be freed or modified before drop() call)
@@ -121,7 +121,7 @@ ZHB_EXPORT zhban_t *zhban_open(const void *data, const uint32_t size,
                                 uint32_t pixheight,
                                 uint32_t subpixel_positioning,
                                 uint32_t glyphlimit, uint32_t sizerlimit, uint32_t renderlimit,
-                                int llevel, logsink_t lsink);
+                                int llevel, zhban_logsink_t lsink);
 ZHB_EXPORT void zhban_drop(zhban_t *);
 
 /* HarfBuzz specifics for non-latin/cyrillic scripts: