Changeset 220 for cpp/common/stl-util.cpp

Timestamp:

04/07/14 02:58:00 (11 years ago)

Author:

Maciej Komosinski

Message:

• moved vsnprintf-related #defines to nonstd.h
• ssprintf_va() now works with non-C99 conformant vsnprintf(): when possible, it obtains the required number of characters in a single call instead of iterating

File:

• cpp/common/stl-util.cpp (modified) (1 diff)

cpp/common/stl-util.cpp

@@ -9 +9 @@
 #include "nonstd.h"
 #include "framsg.h"
+#include <assert.h>
 
 string ssprintf_va(const char* format, va_list ap)
 {
-        string s; //clang crashed when this declaration was in s=buf - dreadful GOTO? - i doubt it... goto did not skip over any variable declarations in this case
-        long size=1000;
+        string s; //clang crashed when this declaration was in s=buf
+        long size=256;
         char* buf;
-retry:
-        buf=(char*)malloc(size);
-        if (vsnprintf(buf,size,format,ap)>=size) {free(buf); size*=4; goto retry;}
-        s=buf;
-        free(buf);
-        return s;
+
+        //almost like SString::sprintf, but there is no common code to share because SString can use its directWrite to avoid double allocating/copying
+#ifdef USE_VSCPRINTF
+        size=_vscprintf(format, ap);
+#endif
+
+        while(1)
+                {
+                buf=(char*)malloc(size);
+                assert(buf!=NULL);
+                int n=vsnprintf(buf,size,format,ap);
+                if (n > -1 && n < size)
+                        {
+                        s=buf;
+                        free(buf);
+                        return s;
+                        }
+#ifdef VSNPRINTF_RETURNS_REQUIRED_SIZE
+                if (n > -1)    /* glibc 2.1 */
+                        size = n+1; /* precisely what is needed */
+                else           /* glibc 2.0 */
+#endif
+                        size *= 2;  /* twice the old size */
+                free(buf);
+                }
 }