FFstrbuf: improve performance of InitF

src/util/FFstrbuf.c

@@ -26,14 +26,23 @@ void ffStrbufInitF(FFstrbuf* strbuf, const char* format, ...)
 {
     assert(format != NULL);
 
-    ffStrbufInit(strbuf);
-
     va_list arguments;
     va_start(arguments, format);
-    ffStrbufAppendVF(strbuf, format, arguments);
+    ffStrbufInitVF(strbuf, format, arguments);
     va_end(arguments);
 }
 
+void ffStrbufInitVF(FFstrbuf* strbuf, const char* format, va_list arguments)
+{
+    assert(format != NULL);
+
+    int len = vasprintf(&strbuf->chars, format, arguments);
+    assert(len >= 0);
+
+    strbuf->allocated = (uint32_t)(len + 1);
+    strbuf->length = (uint32_t)len;
+}
+
 uint32_t ffStrbufGetFree(const FFstrbuf* strbuf)
 {
     assert(strbuf != NULL);
@@ -168,10 +177,13 @@ void ffStrbufSetF(FFstrbuf* strbuf, const char* format, ...)
 {
     assert(format != NULL);
 
-    ffStrbufClear(strbuf);
-
     va_list arguments;
     va_start(arguments, format);
+
+    if(strbuf->allocated == 0)
+        return ffStrbufInitVF(strbuf, format, arguments);
+
+    ffStrbufClear(strbuf);
     ffStrbufAppendVF(strbuf, format, arguments);
     va_end(arguments);
 }

src/util/FFstrbuf.h

@@ -32,6 +32,7 @@ typedef struct FFstrbuf
 void ffStrbufInitA(FFstrbuf* strbuf, uint32_t allocate);
 void ffStrbufInitCopy(FFstrbuf* strbuf, const FFstrbuf* src);
 void ffStrbufInitF(FFstrbuf* strbuf, const char* format, ...);
+void ffStrbufInitVF(FFstrbuf* strbuf, const char* format, va_list arguments);
 
 void ffStrbufEnsureFree(FFstrbuf* strbuf, uint32_t free);
 

tests/strbuf.c

@@ -199,6 +199,13 @@ int main(int argc, char** argv)
 
     ffStrbufDestroy(&strbuf);
 
+    //initF
+    ffStrbufInitF(&strbuf, "%s", "1234567890123456789012345678901");
+    VERIFY(strbuf.allocated == 32);
+    VERIFY(ffStrbufEqualS(&strbuf, "1234567890123456789012345678901"));
+
+    ffStrbufDestroy(&strbuf);
+
     //Success
     puts("\033[32mAll tests passed!"FASTFETCH_TEXT_MODIFIER_RESET);
 }