media: Simplify CdmHostFile(s)

content/common/media/cdm_host_files.cc

 // 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.
 
 #include "content/common/media/cdm_host_files.h"
 
 #include <map>
 #include <memory>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/native_library.h"
 #include "base/path_service.h"
 #include "base/scoped_native_library.h"
 #include "build/build_config.h"
 #include "content/common/media/cdm_host_file.h"
 #include "content/public/common/cdm_info.h"
 #include "content/public/common/content_client.h"
-#include "media/base/media_switches.h"
 #include "media/cdm/api/content_decryption_module_ext.h"
 #include "media/cdm/cdm_paths.h"
 
 #if defined(POSIX_WITH_ZYGOTE)
 #include "content/common/pepper_plugin_list.h"
 #include "content/public/common/pepper_plugin_info.h"
 #endif
 
 #include "widevine_cdm_version.h"  // In SHARED_INTERMEDIATE_DIR.
 
 namespace content {
 
 namespace {
 
-bool IgnoreMissingCdmHostFile() {
-  return base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kIgnoreMissingCdmHostFile);
-}
-
 // TODO(xhwang): Move this to a common place if needed.
 const base::FilePath::CharType kSignatureFileExtension[] =
     FILE_PATH_LITERAL(".sig");
 
 // Returns the signature file path given the |file_path|. This function should
 // only be used when the signature file and the file are located in the same
 // directory, which is the case for the CDM and CDM adapter.
 base::FilePath GetSigFilePath(const base::FilePath& file_path) {
   return file_path.AddExtension(kSignatureFileExtension);
 }
@@ skipping 59 matching lines @@
 }
 
 #if defined(POSIX_WITH_ZYGOTE)
 // static
 void CdmHostFiles::CreateGlobalInstance() {
   DVLOG(1) << __func__;
   DCHECK(!g_cdm_host_files.Get().get());
 
   std::unique_ptr<CdmHostFiles> cdm_host_files =
       base::MakeUnique<CdmHostFiles>();
-  if (!cdm_host_files->OpenFilesForAllRegisteredCdms()) {
-    DVLOG(1) << __func__ << " failed.";
-    cdm_host_files.reset();
-    return;
-  }
-
+  cdm_host_files->OpenFilesForAllRegisteredCdms();
   g_cdm_host_files.Get().reset(cdm_host_files.release());
 }
 
 // static
 std::unique_ptr<CdmHostFiles> CdmHostFiles::TakeGlobalInstance() {
   return std::move(g_cdm_host_files.Get());
 }
 #endif
 
 // static
 std::unique_ptr<CdmHostFiles> CdmHostFiles::Create(
     const base::FilePath& cdm_adapter_path) {
   DVLOG(1) << __func__;
   std::unique_ptr<CdmHostFiles> cdm_host_files =
       base::MakeUnique<CdmHostFiles>();
-  if (!cdm_host_files->OpenFiles(cdm_adapter_path)) {
-    cdm_host_files.reset();
-    return nullptr;
-  }
-
+  cdm_host_files->OpenFiles(cdm_adapter_path);
   return cdm_host_files;
 }
 
 bool CdmHostFiles::VerifyFiles(base::NativeLibrary cdm_adapter_library,
                                const base::FilePath& cdm_adapter_path) {
   DVLOG(1) << __func__;
   DCHECK(cdm_adapter_library);
 
   // Get function pointer exported by the CDM.
   // See media/cdm/api/content_decryption_module_ext.h.
@@ skipping 27 matching lines @@
                                                 kVerifyCdmHostFuncName));
   if (!verify_cdm_host_func) {
     LOG(ERROR) << "Function " << kVerifyCdmHostFuncName << " not found.";
     CloseAllFiles();
     return true;
   }
 
   // Fills |cdm_host_files| with common and CDM specific files for
   // |cdm_adapter_path|.
   std::vector<cdm::HostFile> cdm_host_files;
-  if (!TakePlatformFiles(cdm_adapter_path, &cdm_host_files)) {
-    DVLOG(1) << "Failed to take platform files.";
-    CloseAllFiles();
-    return true;
-  }
+  TakePlatformFiles(cdm_adapter_path, &cdm_host_files);
+
+  // All remaining files will be closed (e.g. files for other CDMs).
+  CloseAllFiles();
+
+  // std::vector::data() is not guaranteed to be nullptr when empty().
+  const cdm::HostFile* cdm_host_files_ptr =
+      cdm_host_files.empty() ? nullptr : cdm_host_files.data();
 
   // Call |verify_cdm_host_func| on the CDM with |cdm_host_files|. Note that
   // the ownership of these files are transferred to the CDM, which will close
   // the files immediately after use.
   DVLOG(1) << __func__ << ": Calling " << kVerifyCdmHostFuncName << "().";
-  if (!verify_cdm_host_func(cdm_host_files.data(), cdm_host_files.size())) {
+  if (!verify_cdm_host_func(cdm_host_files_ptr, cdm_host_files.size())) {
     DVLOG(1) << "Failed to verify CDM host.";
-    CloseAllFiles();
     return false;
   }
 
   // Close all files not passed to the CDM.
-  CloseAllFiles();
   return true;
 }
 
 #if defined(POSIX_WITH_ZYGOTE)
-bool CdmHostFiles::OpenFilesForAllRegisteredCdms() {
+void CdmHostFiles::OpenFilesForAllRegisteredCdms() {
   std::vector<base::FilePath> cdm_adapter_paths;
   GetRegisteredCdms(&cdm_adapter_paths);
   if (cdm_adapter_paths.empty()) {
     DVLOG(1) << "No CDM registered.";
-    return false;
+    return;
   }
 
-  // Ignore
-  for (auto& cdm_adapter_path : cdm_adapter_paths) {
-    bool result = OpenCdmFiles(cdm_adapter_path);
-    if (!result)
-      DVLOG(1) << "CDM files cannot be opened for " << cdm_adapter_path.value();
-    // Ignore the failure and try other registered CDM.
-  }
+  for (auto& cdm_adapter_path : cdm_adapter_paths)
+    OpenCdmFiles(cdm_adapter_path);
 
-  if (cdm_specific_files_map_.empty()) {
-    DVLOG(1) << "CDM specific files cannot be opened for any registered CDM.";
-    return false;
-  }
-
-  return OpenCommonFiles();
+  OpenCommonFiles();
 }
 #endif
 
-bool CdmHostFiles::OpenFiles(const base::FilePath& cdm_adapter_path) {
-  if (!OpenCdmFiles(cdm_adapter_path))
-    return false;
-
-  return OpenCommonFiles();
+void CdmHostFiles::OpenFiles(const base::FilePath& cdm_adapter_path) {
+  OpenCdmFiles(cdm_adapter_path);
+  OpenCommonFiles();
 }
 
-bool CdmHostFiles::OpenCommonFiles() {
+void CdmHostFiles::OpenCommonFiles() {
   DCHECK(common_files_.empty());
 
   std::vector<CdmHostFilePath> cdm_host_file_paths;
   GetContentClient()->AddContentDecryptionModules(nullptr,
                                                   &cdm_host_file_paths);
 
   for (const CdmHostFilePath& value : cdm_host_file_paths) {
-    std::unique_ptr<CdmHostFile> cdm_host_file =
-        CdmHostFile::Create(value.file_path, value.sig_file_path);
-    if (cdm_host_file) {
-      common_files_.push_back(std::move(cdm_host_file));
-      continue;
-    }
-
-    if (!IgnoreMissingCdmHostFile())
-      return false;
+    common_files_.push_back(
+        CdmHostFile::Create(value.file_path, value.sig_file_path));
   }
-
-  return true;
 }
 
-bool CdmHostFiles::OpenCdmFiles(const base::FilePath& cdm_adapter_path) {
+void CdmHostFiles::OpenCdmFiles(const base::FilePath& cdm_adapter_path) {
   DCHECK(!cdm_adapter_path.empty());
   DCHECK(!cdm_specific_files_map_.count(cdm_adapter_path));
 
   std::unique_ptr<CdmHostFile> cdm_adapter_file =
       CdmHostFile::Create(cdm_adapter_path, GetSigFilePath(cdm_adapter_path));
-  if (!cdm_adapter_file)
-    return false;
 
   base::FilePath cdm_path = GetCdmPath(cdm_adapter_path);
   std::unique_ptr<CdmHostFile> cdm_file =
       CdmHostFile::Create(cdm_path, GetSigFilePath(cdm_path));
-  if (!cdm_file)
-    return false;
 
   ScopedFileVector cdm_specific_files;
   cdm_specific_files.reserve(2);
   cdm_specific_files.push_back(std::move(cdm_adapter_file));
   cdm_specific_files.push_back(std::move(cdm_file));
 
   cdm_specific_files_map_[cdm_adapter_path] = std::move(cdm_specific_files);
-  return true;
 }
 
-bool CdmHostFiles::TakePlatformFiles(
+void CdmHostFiles::TakePlatformFiles(
     const base::FilePath& cdm_adapter_path,
     std::vector<cdm::HostFile>* cdm_host_files) {
   DCHECK(cdm_host_files->empty());
 
-  if (!IgnoreMissingCdmHostFile())
-    DCHECK(!common_files_.empty());
-
-  // Check whether CDM specific files exist.
-  const auto& iter = cdm_specific_files_map_.find(cdm_adapter_path);
-  if (iter == cdm_specific_files_map_.end()) {
-    // This could happen on Linux where CDM files fail to open for Foo CDM, but
-    // now we hit Bar CDM.
-    DVLOG(1) << "No CDM specific files for " << cdm_adapter_path.value();
-    return false;
-  }
-
-  const ScopedFileVector& cdm_specific_files = iter->second;
-
-  cdm_host_files->reserve(common_files_.size() + cdm_specific_files.size());
-
   // Populate an array of cdm::HostFile.
   for (const auto& file : common_files_)
     cdm_host_files->push_back(file->TakePlatformFile());
 
-  for (const auto& file : cdm_specific_files)
-    cdm_host_files->push_back(file->TakePlatformFile());
-
-  return true;
+  // Check whether CDM specific files exist.
+  const auto& iter = cdm_specific_files_map_.find(cdm_adapter_path);
+  if (iter == cdm_specific_files_map_.end()) {
+    NOTREACHED() << "No CDM specific files for " << cdm_adapter_path.value();
+  } else {
+    const ScopedFileVector& cdm_specific_files = iter->second;
+    for (const auto& file : cdm_specific_files)
+      cdm_host_files->push_back(file->TakePlatformFile());
+  }
 }
 
 void CdmHostFiles::CloseAllFiles() {
   common_files_.clear();
   cdm_specific_files_map_.clear();
 }
 
 // Question(xhwang): Any better way to check whether a plugin is a CDM? Maybe
 // when we register the plugin we can set some flag explicitly?
 bool IsCdm(const base::FilePath& cdm_adapter_path) {
   return !GetCdmPath(cdm_adapter_path).empty();
 }
 
 }  // namespace content