mediaview: Implement ArcDocumentsProviderRoot.

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.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 "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h"
 
+#include <algorithm>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/files/file.h"
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h"
+#include "chrome/browser/chromeos/arc/fileapi/arc_file_system_instance_util.h"
 #include "content/public/browser/browser_thread.h"
+#include "net/base/mime_util.h"
 
 using content::BrowserThread;
+using EntryList = storage::AsyncFileUtil::EntryList;
 
 namespace arc {
 
+namespace {
+
+// Computes a file name for a document.
+base::FilePath::StringType GetFileNameForDocument(
+    const mojom::DocumentPtr& document) {
+  base::FilePath::StringType filename = document->display_name;
+
+  // Replace path separators appearing in the file name.
+  // Chrome OS is POSIX and kSeparators is "/".
+  base::ReplaceChars(filename, base::FilePath::kSeparators, "_", &filename);
+
+  // Do not allow an empty file name and all-dots file names.
+  if (filename.empty() ||
+      filename.find_first_not_of('.', 0) == std::string::npos) {
+    filename = "_";
+  }
+
+  // Since Chrome detects MIME type from file name extensions, we need to change
+  // the file name extension of the document if it does not match with its MIME
+  // type.
+  // For example, Audio Media Provider presents a music file with its title as
+  // the file name.
+  base::FilePath::StringType extension =
+      base::ToLowerASCII(base::FilePath(filename).Extension());
+  if (!extension.empty())
+    extension = extension.substr(1);  // Strip the leading dot.
+  std::vector<base::FilePath::StringType> possible_extensions;
+  net::GetExtensionsForMimeType(document->mime_type, &possible_extensions);
+  if (!possible_extensions.empty() &&
+      std::find(possible_extensions.begin(), possible_extensions.end(),
+                extension) == possible_extensions.end()) {
+    std::string new_extension;

[hashimoto, 2016/12/20 04:55:07]

This should be base::FilePath::StringType.

[Shuhei Takahashi, 2016/12/20 06:08:24]

Done.

+    if (!net::GetPreferredExtensionForMimeType(document->mime_type,
+                                               &new_extension)) {
+      new_extension = possible_extensions[0];
+    }
+    filename = base::FilePath(filename).AddExtension(new_extension).value();
+  }
+
+  return filename;
+}
+
+}  // namespace
+
 ArcDocumentsProviderRoot::ArcDocumentsProviderRoot(
     const std::string& authority,
-    const std::string& root_document_id) {}
+    const std::string& root_document_id)
+    : authority_(authority),
+      root_document_id_(root_document_id),
+      weak_ptr_factory_(this) {}
 
 ArcDocumentsProviderRoot::~ArcDocumentsProviderRoot() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 }
 
 void ArcDocumentsProviderRoot::GetFileInfo(
     const base::FilePath& path,
     const GetFileInfoCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  NOTIMPLEMENTED();  // TODO(crbug.com/671511): Implement this function.
+  ResolveToDocumentId(
+      path, base::Bind(&ArcDocumentsProviderRoot::GetFileInfoWithDocumentId,
+                       weak_ptr_factory_.GetWeakPtr(), callback));
 }
 
 void ArcDocumentsProviderRoot::ReadDirectory(
     const base::FilePath& path,
     const ReadDirectoryCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  NOTIMPLEMENTED();  // TODO(crbug.com/671511): Implement this function.
+  ResolveToDocumentId(
+      path, base::Bind(&ArcDocumentsProviderRoot::ReadDirectoryWithDocumentId,
+                       weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void ArcDocumentsProviderRoot::GetFileInfoWithDocumentId(
+    const GetFileInfoCallback& callback,
+    const std::string& document_id) {
+  if (document_id.empty()) {
+    callback.Run(base::File::FILE_ERROR_NOT_FOUND, base::File::Info());
+    return;
+  }
+  file_system_instance_util::GetDocumentOnIOThread(
+      authority_, document_id,
+      base::Bind(&ArcDocumentsProviderRoot::GetFileInfoWithDocument,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void ArcDocumentsProviderRoot::GetFileInfoWithDocument(
+    const GetFileInfoCallback& callback,
+    mojom::DocumentPtr document) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (document.is_null()) {
+    callback.Run(base::File::FILE_ERROR_NOT_FOUND, base::File::Info());
+    return;
+  }
+  base::File::Info info;
+  info.size = document->size;
+  info.is_directory = document->mime_type == kAndroidDirectoryMimeType;
+  info.is_symbolic_link = false;
+  info.last_modified = info.last_accessed = info.creation_time =
+      base::Time::FromJavaTime(document->last_modified);
+  callback.Run(base::File::FILE_OK, info);
+}
+
+void ArcDocumentsProviderRoot::ReadDirectoryWithDocumentId(
+    const ReadDirectoryCallback& callback,
+    const std::string& document_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (document_id.empty()) {
+    callback.Run(base::File::FILE_ERROR_NOT_FOUND, EntryList(),
+                 false /* has_more */);
+    return;
+  }
+  ReadDirectoryInternal(
+      document_id,
+      base::Bind(&ArcDocumentsProviderRoot::ReadDirectoryWithNameMapping,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void ArcDocumentsProviderRoot::ReadDirectoryWithNameMapping(
+    const ReadDirectoryCallback& callback,
+    NameMapping mapping) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  std::vector<storage::DirectoryEntry> entry_list;
+  for (const auto& pair : mapping) {
+    entry_list.emplace_back(pair.first, pair.second.is_directory
+                                            ? storage::DirectoryEntry::DIRECTORY
+                                            : storage::DirectoryEntry::FILE);
+  }
+  callback.Run(base::File::FILE_OK, entry_list, false /* has_more */);
+}
+
+void ArcDocumentsProviderRoot::ResolveToDocumentId(
+    const base::FilePath& path,
+    const ResolveToDocumentIdCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  std::vector<base::FilePath::StringType> components;
+  path.GetComponents(&components);
+  ResolveToDocumentIdRecursively(root_document_id_, components, callback);
+}
+
+void ArcDocumentsProviderRoot::ResolveToDocumentIdRecursively(
+    const std::string& document_id,
+    const std::vector<base::FilePath::StringType>& components,
+    const ResolveToDocumentIdCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (components.empty()) {
+    callback.Run(document_id);
+    return;
+  }
+  ReadDirectoryInternal(
+      document_id,
+      base::Bind(&ArcDocumentsProviderRoot::
+                     ResolveToDocumentIdRecursivelyWithNameMapping,
+                 weak_ptr_factory_.GetWeakPtr(), components, callback));
+}
+
+void ArcDocumentsProviderRoot::ResolveToDocumentIdRecursivelyWithNameMapping(
+    const std::vector<base::FilePath::StringType>& components,
+    const ResolveToDocumentIdCallback& callback,
+    NameMapping mapping) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(!components.empty());
+  auto iter = mapping.find(components[0]);
+  if (iter == mapping.end()) {
+    callback.Run(std::string());
+    return;
+  }
+  ResolveToDocumentIdRecursively(iter->second.document_id,
+                                 std::vector<base::FilePath::StringType>(
+                                     components.begin() + 1, components.end()),
+                                 callback);
+}
+
+void ArcDocumentsProviderRoot::ReadDirectoryInternal(
+    const std::string& document_id,
+    const ReadDirectoryInternalCallback& callback) {
+  file_system_instance_util::GetChildDocumentsOnIOThread(
+      authority_, document_id,
+      base::Bind(
+          &ArcDocumentsProviderRoot::ReadDirectoryInternalWithChildDocuments,
+          weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void ArcDocumentsProviderRoot::ReadDirectoryInternalWithChildDocuments(
+    const ReadDirectoryInternalCallback& callback,
+    base::Optional<std::vector<mojom::DocumentPtr>> maybe_children) {
+  if (!maybe_children) {
+    callback.Run(NameMapping());

[hashimoto, 2016/12/20 04:55:07]

ReadDirectoryInternal cannot return errors when the specified directory doesn't
exist.
Doesn't this cause any problems?
If so, it'd be nice to have a comment to describe the justification.

[Shuhei Takahashi, 2016/12/20 06:08:24]

Makes sense, let's return errors from ReadDirectoryInternal.

+    return;
+  }
+  std::vector<mojom::DocumentPtr>& children = maybe_children.value();
+
+  // Sort entries to keep the mapping stable as far as possible.
+  std::sort(children.begin(), children.end(),
+            [](const mojom::DocumentPtr& a, const mojom::DocumentPtr& b) {
+              return a->document_id < b->document_id;
+            });
+
+  NameMapping mapping;
+  std::map<base::FilePath::StringType, int> suffix_counters;
+
+  for (const mojom::DocumentPtr& document : children) {
+    base::FilePath::StringType filename = GetFileNameForDocument(document);
+
+    if (mapping.count(filename) > 0) {
+      // Resolve a conflict by adding a suffix.
+      int& suffix_counter = suffix_counters[filename];
+      while (true) {
+        ++suffix_counter;
+        std::string suffix = base::StringPrintf(" %d", suffix_counter);

[hashimoto, 2016/12/20 04:55:07]

Drive code uses "(n)" instead of "n" as suffix.
It'd be nice to be consistent.
https://cs.chromium.org/chromium/src/components/drive/chromeos/resource_metad...

Probably we should make a change later to share the same code (as well as file
name escape code above).

[Shuhei Takahashi, 2016/12/20 06:08:24]

Changed to (n). Yes, it would be good if we can consolidate those codes. If you
know a good place to put the shared code please let me know.

[hashimoto, 2016/12/20 06:24:18]

Somewhere under components (probably a new directory) or in
storage/browser/fileapi?

[Shuhei Takahashi, 2016/12/20 06:32:49]

Thanks, filed crbug.com/675868.

+        base::FilePath::StringType new_filename =
+            base::FilePath(filename).InsertBeforeExtensionASCII(suffix).value();
+        if (mapping.count(new_filename) == 0) {
+          filename = new_filename;
+          break;
+        }
+      }
+    }
+
+    DCHECK_EQ(0u, mapping.count(filename));
+
+    mapping[filename] =
+        ThinDocument{document->document_id,
+                     document->mime_type == kAndroidDirectoryMimeType};
+  }
+
+  callback.Run(std::move(mapping));
 }
 
 }  // namespace arc