components/arc/test/fake_file_system_instance.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 COMPONENTS_ARC_TEST_FAKE_FILE_SYSTEM_INSTANCE_H_
#define COMPONENTS_ARC_TEST_FAKE_FILE_SYSTEM_INSTANCE_H_

#include <stdint.h>

#include <map>
#include <string>
#include <utility>
#include <vector>

#include "base/files/scoped_temp_dir.h"
#include "base/macros.h"
#include "base/threading/thread_checker.h"
#include "components/arc/common/file_system.mojom.h"

namespace arc {

// Fake implementation to operate on documents in memory.
//
// ArcFileSystemOperationRunner provides two types of methods: content URL
// based and documents provider based. According to backend type, you need
// to setup the fake with different functions.
//
// Content URL based functions are:
// - GetFileSize()
// - OpenFileToRead()
// Fake files for those functions can be set up by AddFile().
//
// Documents provider based functions are:
// - GetDocument()
// - GetChildDocuments()
// Fake documents for those functions can be set up by AddDocument().
//
// Notes:
// - GetChildDocuments() returns child documents in the same order as they were
//   added with AddDocument().
// - All member functions must be called on the same thread.
class FakeFileSystemInstance : public mojom::FileSystemInstance {
 public:
  // Specification of a fake file available to content URL based methods.
  struct File {
    enum class Seekable {
      NO,
      YES,
    };

    // Content URL of a file.
    std::string url;

    // The content of a file.
    std::string content;

    // Whether this file is seekable or not.
    Seekable seekable;

    File(const std::string& url, const std::string& content, Seekable seekable);
    File(const File& that);
    ~File();
  };

  // Specification of a fake document available to documents provider based
  // methods.
  struct Document {
    // Authority.
    std::string authority;

    // ID of this document.
    std::string document_id;

    // ID of the parent document. Can be empty if this is a root.
    std::string parent_document_id;

    // File name displayed to users.
    std::string display_name;

    // MIME type.
    std::string mime_type;

    // File size in bytes. Set to -1 if size is not available.
    int64_t size;

    // Last modified time in milliseconds from the UNIX epoch.
    // TODO(crbug.com/672737): Use base::Time once the corresponding field
    // in file_system.mojom stops using uint64.
    uint64_t last_modified;

    Document(const std::string& authority,
             const std::string& document_id,
             const std::string& parent_document_id,
             const std::string& display_name,
             const std::string& mime_type,
             int64_t size,
             uint64_t last_modified);
    Document(const Document& that);
    ~Document();
  };

  FakeFileSystemInstance();
  ~FakeFileSystemInstance() override;

  // Adds a file accessible by content URL based methods.
  void AddFile(const File& file);

  // Adds a document accessible by document provider based methods.
  void AddDocument(const Document& document);

  // mojom::FileSystemInstance:
  void GetChildDocuments(const std::string& authority,
                         const std::string& document_id,
                         const GetChildDocumentsCallback& callback) override;
  void GetDocument(const std::string& authority,
                   const std::string& document_id,
                   const GetDocumentCallback& callback) override;
  void GetFileSize(const std::string& url,
                   const GetFileSizeCallback& callback) override;
  void OpenFileToRead(const std::string& url,
                      const OpenFileToReadCallback& callback) override;
  void RequestMediaScan(const std::vector<std::string>& paths) override;

 private:
  // A pair of an authority and a document ID which identifies the location
  // of a document in documents providers.
  using DocumentKey = std::pair<std::string, std::string>;

  base::ThreadChecker thread_checker_;

  base::ScopedTempDir temp_dir_;

  // Mapping from a content URL to a file.
  std::map<std::string, File> files_;

  // Mapping from a document key to a document.
  std::map<DocumentKey, Document> documents_;

  // Mapping from a document key to its child documents.
  std::map<DocumentKey, std::vector<DocumentKey>> child_documents_;

  DISALLOW_COPY_AND_ASSIGN(FakeFileSystemInstance);
};

}  // namespace arc

#endif  // COMPONENTS_ARC_TEST_FAKE_FILE_SYSTEM_INSTANCE_H_