Add Directory.createTemp() to asynchronously create a temporary directory.

runtime/bin/directory_win.cc

Index: runtime/bin/directory_win.cc
diff --git a/runtime/bin/directory_win.cc b/runtime/bin/directory_win.cc
index 0f48408adc3cc71788df0c547de0dc2c7fb1ebc4..ae905c01decee344753032b7270660057f6cc599 100644
--- a/runtime/bin/directory_win.cc
+++ b/runtime/bin/directory_win.cc
@@ -5,6 +5,7 @@
 #include "bin/directory.h"
 
 #include <errno.h>
+#include <time.h>
 #include <sys/stat.h>
 
 #include "bin/platform.h"
@@ -238,6 +239,35 @@ bool Directory::Create(const char* dir_name) {
 }
 
 
+char* Directory::CreateTemp(const char* const_template) {

[Mads Ager (google), 2011/11/18 09:50:45]

You are not using the template here. So we should change the interface to
something that will make sense on all platforms. The description of the
interface does not match the Windows implementation.

[Bill Hesse, 2011/11/21 15:48:41]

We are using a non-empty template on both platforms, and using the system
directory when passed the empty string.

On 2011/11/18 09:50:45, Mads Ager wrote:

+  // Returns a new, unused directory name, modifying the contents of
+  // dir_template.  Creates this directory, with mode ???.
+  // The return value must be freed by the caller.
+  char* path = static_cast<char*>(malloc(MAX_PATH));
+  int path_length = GetTempPath(MAX_PATH, path);
+  if (path_length > MAX_PATH - 1) {
+	path[0] = '\0';

[Mads Ager (google), 2011/11/18 09:50:45]

Funky indentation. Are there tabs here or something?

[Bill Hesse, 2011/11/21 15:48:41]

Done.

+	return path;
+  }
+
+  strncpy_s(path + path_length, MAX_PATH, "tempdir", 8);

[Mads Ager (google), 2011/11/18 09:50:45]

Use snprintf instead. That is what we have done in the rest of the code.

+  bool success = false;
+  int tries = 0;
+  int numeric_part = time(NULL) % 1000000;

[Mads Ager (google), 2011/11/18 09:50:45]

We could use UuidCreate or something to make it more likely that this will
succeed.

What you are doing here is roughly equivalent to GetTempFileName? I guess you
are doing this to limit it to 100 tries?

[Bill Hesse, 2011/11/21 15:48:41]

Using Math.Random from dart.

On 2011/11/18 09:50:45, Mads Ager wrote:

+  while (!success  && tries < 100) {
+	sprintf(path + path_length + 7, "%.6d", numeric_part);

[Mads Ager (google), 2011/11/18 09:50:45]

snprintf

+	success = CreateDirectory(path, NULL);
+	if (!success) {
+      numeric_part++;
+	  tries++;
+    // Return the empty string, but as a freeable array.
+    // path[0] = '\0';

[Mads Ager (google), 2011/11/18 09:50:45]

Commented out code and very strange indentation.

+	}
+  }
+  return path;
+}
+
+
 bool Directory::Delete(const char* dir_name) {
   return (RemoveDirectory(dir_name) != 0);
 }