1 files changed, 99 insertions, 0 deletions
diff --git a/contrib/ucw/mempool-fmt.c b/contrib/ucw/mempool-fmt.c
new file mode 100644
index 0000000..22f3a50
--- /dev/null
+++ b/contrib/ucw/mempool-fmt.c
@@ -0,0 +1,99 @@
+/*
+ *  UCW Library -- Memory Pools (Formatting)
+ *
+ *  (c) 2005 Martin Mares <mj@ucw.cz>
+ *  (c) 2007 Pavel Charvat <pchar@ucw.cz>
+ *  SPDX-License-Identifier: LGPL-2.1-or-later
+ *  Source: https://www.ucw.cz/libucw/
+ */
+
+#include <ucw/lib.h>
+#include <ucw/mempool.h>
+
+#include <stdio.h>
+#include <string.h>
+
+/* FIXME: migrate to Knot DNS version of mempools. */
+#pragma GCC diagnostic ignored "-Wpointer-arith"
+
+static char *
+mp_vprintf_at(struct mempool *mp, size_t ofs, const char *fmt, va_list args)
+{
+  char *ret = mp_grow(mp, ofs + 1) + ofs;
+  va_list args2;
+  va_copy(args2, args);
+  int cnt = vsnprintf(ret, mp_avail(mp) - ofs, fmt, args2);
+  va_end(args2);
+  if (cnt < 0)
+    {
+      /* Our C library doesn't support C99 return value of vsnprintf, so we need to iterate */
+      do
+  {
+    ret = mp_expand(mp) + ofs;
+    va_copy(args2, args);
+    cnt = vsnprintf(ret, mp_avail(mp) - ofs, fmt, args2);
+    va_end(args2);
+  }
+      while (cnt < 0);
+    }
+  else if ((uint)cnt >= mp_avail(mp) - ofs)
+    {
+      ret = mp_grow(mp, ofs + cnt + 1) + ofs;
+      va_copy(args2, args);
+      vsnprintf(ret, cnt + 1, fmt, args2);
+      va_end(args2);
+    }
+  mp_end(mp, ret + cnt + 1);
+  return ret - ofs;
+}
+
+char *
+mp_vprintf(struct mempool *mp, const char *fmt, va_list args)
+{
+  mp_start(mp, 1);
+  return mp_vprintf_at(mp, 0, fmt, args);
+}
+
+char *
+mp_printf(struct mempool *p, const char *fmt, ...)
+{
+  va_list args;
+  va_start(args, fmt);
+  char *res = mp_vprintf(p, fmt, args);
+  va_end(args);
+  return res;
+}
+
+char *
+mp_vprintf_append(struct mempool *mp, char *ptr, const char *fmt, va_list args)
+{
+  size_t ofs = mp_open(mp, ptr);
+  ASSERT(ofs && !ptr[ofs - 1]);
+  return mp_vprintf_at(mp, ofs - 1, fmt, args);
+}
+
+char *
+mp_printf_append(struct mempool *mp, char *ptr, const char *fmt, ...)
+{
+  va_list args;
+  va_start(args, fmt);
+  char *res = mp_vprintf_append(mp, ptr, fmt, args);
+  va_end(args);
+  return res;
+}
+
+#ifdef TEST
+
+int main(void)
+{
+  struct mempool *mp = mp_new(64);
+  char *x = mp_printf(mp, "<Hello, %s!>", "World");
+  fputs(x, stdout);
+  x = mp_printf_append(mp, x, "<Appended>");
+  fputs(x, stdout);
+  x = mp_printf(mp, "<Hello, %50s!>\n", "World");
+  fputs(x, stdout);
+  return 0;
+}
+
+#endif