mediaview: Implement ArcDocumentsProviderRoot.

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h

Index: chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
diff --git a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
index 41135c9e0c255c8eef3c49e1278c1ad11362bc45..de30a7477b8665dd5d702df176c4a7637bb812dd 100644
--- a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
+++ b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
@@ -5,10 +5,16 @@
 #ifndef CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_DOCUMENTS_PROVIDER_ROOT_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_DOCUMENTS_PROVIDER_ROOT_H_
 
+#include <map>
 #include <string>
+#include <vector>
 
+#include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/optional.h"
+#include "components/arc/common/file_system.mojom.h"
 #include "storage/browser/fileapi/async_file_util.h"
 
 namespace arc {
@@ -16,6 +22,8 @@ namespace arc {
 // Represents a file system root in Android Documents Provider.
 //
 // All methods must be called on the IO thread.
+// If this object is deleted while there are in-flight operations, callbacks
+// for those operations will be never called.
 class ArcDocumentsProviderRoot {
  public:
   using GetFileInfoCallback = storage::AsyncFileUtil::GetFileInfoCallback;
@@ -35,6 +43,60 @@ class ArcDocumentsProviderRoot {
                      const ReadDirectoryCallback& callback);
 
  private:
+  // Thin representation of a document in documents provider.
+  struct ThinDocument {
+    std::string document_id;
+    bool is_directory;
+  };
+
+  // Mapping from a file name to a ThinDocument.
+  using NameToThinDocumentMap =
+      std::map<base::FilePath::StringType, ThinDocument>;
+
+  using ResolveToDocumentIdCallback =
+      base::Callback<void(const std::string& document_id)>;
+  using ReadDirectoryInternalCallback =
+      base::Callback<void(base::File::Error error,
+                          NameToThinDocumentMap mapping)>;
+
+  void GetFileInfoWithDocumentId(const GetFileInfoCallback& callback,
+                                 const std::string& document_id);
+  void GetFileInfoWithDocument(const GetFileInfoCallback& callback,
+                               mojom::DocumentPtr document);
+
+  void ReadDirectoryWithDocumentId(const ReadDirectoryCallback& callback,
+                                   const std::string& document_id);
+  void ReadDirectoryWithNameToThinDocumentMap(
+      const ReadDirectoryCallback& callback,
+      base::File::Error error,
+      NameToThinDocumentMap mapping);
+
+  // Resolves |path| to a document ID. Failures are indicated by an empty
+  // document ID.
+  void ResolveToDocumentId(const base::FilePath& path,
+                           const ResolveToDocumentIdCallback& callback);
+  void ResolveToDocumentIdRecursively(
+      const std::string& document_id,
+      const std::vector<base::FilePath::StringType>& components,
+      const ResolveToDocumentIdCallback& callback);
+  void ResolveToDocumentIdRecursivelyWithNameToThinDocumentMap(
+      const std::vector<base::FilePath::StringType>& components,
+      const ResolveToDocumentIdCallback& callback,
+      base::File::Error error,
+      NameToThinDocumentMap mapping);
+
+  // Enumerates child documents of a directory specified by |document_id|.
+  // The result is returned as a NameToThinDocumentMap.
+  void ReadDirectoryInternal(const std::string& document_id,
+                             const ReadDirectoryInternalCallback& callback);
+  void ReadDirectoryInternalWithChildDocuments(
+      const ReadDirectoryInternalCallback& callback,
+      base::Optional<std::vector<mojom::DocumentPtr>> maybe_children);
+
+  const std::string authority_;
+  const std::string root_document_id_;
+  base::WeakPtrFactory<ArcDocumentsProviderRoot> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(ArcDocumentsProviderRoot);
 };