intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 51 insertions, 0 deletions

diff --git a/util/stream/printf.cpp b/util/stream/printf.cpp
new file mode 100644
index 00000000000..f3eeca7afcb
--- /dev/null
+++ b/util/stream/printf.cpp
@@ -0,0 +1,51 @@
+#include "output.h"
+#include "printf.h"
+
+#include <util/generic/scope.h>
+#include <util/memory/tempbuf.h>
+#include <util/generic/yexception.h>
+
+size_t Printf(IOutputStream& out, const char* fmt, ...) {
+    va_list lst;
+    va_start(lst, fmt);
+
+    Y_DEFER {
+        va_end(lst);
+    };
+
+    return Printf(out, fmt, lst);
+}
+
+static inline size_t TryPrintf(void* ptr, size_t len, IOutputStream& out, const char* fmt, va_list params) {
+    va_list lst;
+    va_copy(lst, params);
+    const int ret = vsnprintf((char*)ptr, len, fmt, lst);
+    va_end(lst);
+
+    if (ret < 0) {
+        return len;
+    }
+
+    if ((size_t)ret < len) {
+        out.Write(ptr, (size_t)ret);
+    }
+
+    return (size_t)ret;
+}
+
+size_t Printf(IOutputStream& out, const char* fmt, va_list params) {
+    size_t guess = 0;
+
+    while (true) {
+        TTempBuf tmp(guess);
+        const size_t ret = TryPrintf(tmp.Data(), tmp.Size(), out, fmt, params);
+
+        if (ret < tmp.Size()) {
+            return ret;
+        }
+
+        guess = Max(tmp.Size() * 2, ret + 1);
+    }
+
+    return 0;
+}