1 files changed, 131 insertions, 0 deletions
diff --git a/src/lib/maybe_con_write.c b/src/lib/maybe_con_write.c
new file mode 100644
index 0000000..43522ef
--- /dev/null
+++ b/src/lib/maybe_con_write.c
@@ -0,0 +1,131 @@
+/* $Id: maybe_con_write.c 3547 2022-01-29 02:39:47Z bird $ */
+/** @file
+ * maybe_con_write - Optimized console output on windows.
+ */
+
+/*
+ * Copyright (c) 2016-2018 knut st. osmundsen <bird-kBuild-spamx@anduin.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Alternatively, the content of this file may be used under the terms of the
+ * GPL version 2 or later, or LGPL version 2.1 or later.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "console.h"
+#ifdef KBUILD_OS_WINDOWS
+# include <windows.h>
+#endif
+#include <errno.h>
+#ifdef _MSC_VER
+# include <conio.h>
+typedef unsigned int to_write_t;
+#else
+typedef size_t to_write_t;
+#endif
+
+
+/**
+ * Drop-in write replacement for optimizing console output on windows.
+ *
+ * @returns Number of bytes written, -1 + errno on failure.
+ * @param   fd                  The file descript to write to.
+ * @param   pvBuf               What to write.
+ * @param   cbToWrite           How much to write.
+ */
+ssize_t maybe_con_write(int fd, void const *pvBuf, size_t cbToWrite)
+{
+    ssize_t cbWritten;
+
+#ifdef KBUILD_OS_WINDOWS
+    /*
+     * If it's a TTY, do our own conversion to wide char and
+     * call WriteConsoleW directly.
+     */
+    if (cbToWrite > 0 && cbToWrite < INT_MAX / 2)
+    {
+        HANDLE hCon = (HANDLE)_get_osfhandle(fd);
+        if (   hCon != INVALID_HANDLE_VALUE
+            && hCon != NULL)
+        {
+            if (is_console_handle((intptr_t)hCon))
+            {
+                wchar_t  awcBuf[1024];
+                wchar_t *pawcBuf;
+                wchar_t *pawcBufFree = NULL;
+                size_t   cwcBuf      = cbToWrite * 2 + 16;
+                if (cwcBuf < sizeof(awcBuf) / sizeof(awcBuf[0]))
+                {
+                    pawcBuf = awcBuf;
+                    cwcBuf  = sizeof(awcBuf) / sizeof(awcBuf[0]);
+                }
+                else
+                    pawcBufFree = pawcBuf = (wchar_t *)malloc(cwcBuf * sizeof(wchar_t));
+                if (pawcBuf)
+                {
+                    int cwcToWrite = MultiByteToWideChar(get_crt_codepage(), 0 /*dwFlags*/,
+                                                         pvBuf, (int)cbToWrite,
+                                                         pawcBuf, (int)(cwcBuf - 1));
+                    if (cwcToWrite > 0)
+                    {
+                        int rc;
+                        pawcBuf[cwcToWrite] = '\0';
+
+                        /* Let the CRT do the rest.  At least the Visual C++ 2010 CRT
+                           sources indicates _cputws will do the right thing.  */
+                        rc = _cputws(pawcBuf);
+                        if (pawcBufFree)
+                            free(pawcBufFree);
+                        if (rc >= 0)
+                            return cbToWrite;
+                        return -1;
+                    }
+                    free(pawcBufFree);
+                }
+            }
+        }
+    }
+#endif
+
+    /*
+     * Semi regular write handling.
+     */
+    cbWritten = write(fd, pvBuf, (to_write_t)cbToWrite);
+    if (cbWritten == (ssize_t)cbToWrite)
+    { /* likely */ }
+    else if (cbWritten >= 0 || errno == EINTR)
+    {
+        if (cbWritten < 0)
+            cbWritten = 0;
+        while (cbWritten < (ssize_t)cbToWrite)
+        {
+            ssize_t cbThis = write(fd, (char *)pvBuf + cbWritten, (to_write_t)(cbToWrite - cbWritten));
+            if (cbThis >= 0)
+                cbWritten += cbThis;
+            else if (errno != EINTR)
+                return -1;
+        }
+    }
+    return cbWritten;
+}
+