Add VerifyHostFiles()

content_decryption_module_ext.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CDM_CONTENT_DECRYPTION_MODULE_EXT_H_
+#define CDM_CONTENT_DECRYPTION_MODULE_EXT_H_
+
+#if defined(WIN32)
+#include <windows.h>
+#endif
+
+#include "content_decryption_module_export.h"
+
+#if defined(_MSC_VER)
+typedef unsigned int uint32_t;

[ddorwin, 2017/01/13 08:27:51]

Is this still required even with the latest VS version we use? Maybe there are
other users that support older compilers.

[xhwang, 2017/01/13 18:34:06]

I am not sure.
That's actually possible. Acknowledged.

+#else
+#include <stdint.h>
+#endif
+
+#if defined(WIN32)
+typedef wchar_t FilePathCharType;
+typedef HANDLE CdmPlatformFile;
+const CdmPlatformFile kInvalidPlatformFile = INVALID_HANDLE_VALUE;
+#elif defined(OS_POSIX)
+typedef char FilePathCharType;
+typedef int CdmPlatformFile;

[ddorwin, 2017/01/13 08:27:51]

...Id? ...Handle? As is, it would appear to be an object. I guess that's okay,
but clarity seems better. WDYT?

[xhwang, 2017/01/13 18:34:06]

PlatformFile comes from base/file/file.h

https://cs.chromium.org/chromium/src/base/files/file.h?rcl=0&l=32

I guess the whole point is that user should not care whether this is an object
or not. So I'd like t err on the consistency side.

Also, I moved this block into the cdm:: namespace to avoid name collisions.

[ddorwin, 2017/01/13 18:47:38]

Acknowledged.

+const CdmPlatformFile kInvalidPlatformFile = -1;
+#endif  // defined(WIN32)

[ddorwin, 2017/01/13 08:27:51]

Should we #error?

[xhwang, 2017/01/13 18:34:06]

Done.

+
+namespace cdm {
+
+struct CdmHostFile {
+  CdmHostFile(const FilePathCharType* file_path,
+              CdmPlatformFile file,
+              CdmPlatformFile sig_file)
+      : file_path(file_path), file(file), sig_file(sig_file) {}

[ddorwin, 2017/01/13 08:27:51]

The members and parameters have the same exact name. Does that compile?

[xhwang, 2017/01/13 18:34:06]

Yes. Please see related discussion here:
http://stackoverflow.com/questions/6185020/initializing-member-variables-usin...

+
+  const FilePathCharType* file_path = nullptr;
+  CdmPlatformFile file = kInvalidPlatformFile;
+  CdmPlatformFile sig_file = kInvalidPlatformFile;
+};
+
+}  // namespace cdm
+
+extern "C" {
+
+// Verifies CDM host files, which are opened in read-only mode and passed in
+// |cdm_host_files|. The CDM should return as soon as possible and process the

[ddorwin, 2017/01/13 08:27:51]

s/should/MUST/ here and below.

[xhwang, 2017/01/13 18:34:06]

Done.

+// files asynchronously. All files should be closed by the CDM after the
+// processing is finished.

[ddorwin, 2017/01/13 08:27:51]

...this one-time processing...

To make it clear that they need to be closed ASAP.

[xhwang, 2017/01/13 18:34:06]

Done.

+CDM_API void VerifyHostFiles(const cdm::CdmHostFile* cdm_host_files,
+                             uint32_t num_files);
+}
+
+#endif  // CDM_CONTENT_DECRYPTION_MODULE_EXT_H_