metrics/base: log whether drives have seek penalties.

base/sys_info_win.cc

Index: base/sys_info_win.cc
diff --git a/base/sys_info_win.cc b/base/sys_info_win.cc
index 9cc0cfa48a3637d48c36978de2c798383e9a194d..0a20b6c2e4b379b96328191d4a484fd6c5988e82 100644
--- a/base/sys_info_win.cc
+++ b/base/sys_info_win.cc
@@ -5,12 +5,14 @@
 #include "base/sys_info.h"
 
 #include <windows.h>
+#include <winioctl.h>
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
+#include "base/win/scoped_handle.h"
 #include "base/win/windows_version.h"
 
 namespace {
@@ -55,16 +57,56 @@ int64 SysInfo::AmountOfVirtualMemory() {
 
 // static
 int64 SysInfo::AmountOfFreeDiskSpace(const FilePath& path) {
-  base::ThreadRestrictions::AssertIOAllowed();
+  ThreadRestrictions::AssertIOAllowed();
 
   ULARGE_INTEGER available, total, free;
-  if (!GetDiskFreeSpaceExW(path.value().c_str(), &available, &total, &free)) {
+  if (!GetDiskFreeSpaceExW(path.value().c_str(), &available, &total, &free))
     return -1;
-  }
+
   int64 rv = static_cast<int64>(available.QuadPart);
-  if (rv < 0)
-    rv = kint64max;
-  return rv;
+  return rv < 0 ? kint64max : rv;
+}
+
+bool SysInfo::HasSeekPenalty(const FilePath& path, bool* has_seek_penalty) {
+  ThreadRestrictions::AssertIOAllowed();
+
+  if (!path.IsAbsolute() || !has_seek_penalty)

[rvargas (doing something else), 2015/03/12 22:01:12]

I would probably also DCHECK the first condition given that it is a precondition
and not something that the caller cannot control.

[Dan Beam, 2015/03/13 19:31:32]

Done.

+    return false;
+
+  std::vector<FilePath::StringType> components;
+  path.GetComponents(&components);
+
+  FilePath::StringType drive = L"\\\\.\\" + components[0];

[rvargas (doing something else), 2015/03/12 22:01:12]

This syntax is not supported before win7

[Dan Beam, 2015/03/13 19:31:32]

Acknowledged.

+  win::ScopedHandle handle(CreateFile(

[rvargas (doing something else), 2015/03/12 22:01:12]

Looks like a job for base::File

[Dan Beam, 2015/03/13 19:31:32]

Done.

+      drive.c_str(),
+      0,
+      FILE_SHARE_READ | FILE_SHARE_WRITE,
+      NULL,
+      OPEN_EXISTING,
+      0,
+      NULL));
+
+  if (!handle.IsValid())
+    return false;
+
+  STORAGE_PROPERTY_QUERY query;
+  query.QueryType = PropertyStandardQuery;
+  query.PropertyId = StorageDeviceSeekPenaltyProperty;

[rvargas (doing something else), 2015/03/12 22:01:11]

Not supported on XP

[Dan Beam, 2015/03/13 19:31:32]

Acknowledged.

+
+  DEVICE_SEEK_PENALTY_DESCRIPTOR result;
+  DWORD unused_bytes_returned;
+
+  if (!DeviceIoControl(handle.Get(),
+                       IOCTL_STORAGE_QUERY_PROPERTY,
+                       &query, sizeof(query),
+                       &result, sizeof(result),
+                       &unused_bytes_returned,

[rvargas (doing something else), 2015/03/12 22:01:12]

Verify that this is >= sizeof(result) before accessing the result.

[Dan Beam, 2015/03/13 19:31:32]

Done.

+                       NULL)) {
+    return false;
+  }
+
+  *has_seek_penalty = !!result.IncursSeekPenalty;

[rvargas (doing something else), 2015/03/12 22:01:12]

nit: != FALSE? (I hate using "!!" to do this).

[Dan Beam, 2015/03/13 19:31:32]

why not == TRUE?

+  return true;
 }
 
 // static