1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef AAPT_IO_FILE_H
18#define AAPT_IO_FILE_H
19
20#include <list>
21#include <memory>
22#include <vector>
23
24#include "android-base/macros.h"
25
26#include "Source.h"
27#include "io/Data.h"
28#include "util/Util.h"
29
30namespace aapt {
31namespace io {
32
33// Interface for a file, which could be a real file on the file system, or a
34// file inside a ZIP archive.
35class IFile {
36 public:
37  virtual ~IFile() = default;
38
39  // Open the file and return it as a block of contiguous memory. How this
40  // occurs is implementation dependent. For example, if this is a file on the file
41  // system, it may simply mmap the contents. If this file represents a compressed file in a
42  // ZIP archive, it may need to inflate it to memory, incurring a copy.
43  // Returns nullptr on failure.
44  virtual std::unique_ptr<IData> OpenAsData() = 0;
45
46  // Returns the source of this file. This is for presentation to the user and
47  // may not be a valid file system path (for example, it may contain a '@' sign to separate
48  // the files within a ZIP archive from the path to the containing ZIP archive.
49  virtual const Source& GetSource() const = 0;
50
51  IFile* CreateFileSegment(size_t offset, size_t len);
52
53  // Returns whether the file was compressed before it was stored in memory.
54  virtual bool WasCompressed() {
55    return false;
56  }
57
58 private:
59  // Any segments created from this IFile need to be owned by this IFile, so
60  // keep them
61  // in a list. This will never be read, so we prefer better insertion
62  // performance
63  // than cache locality, hence the list.
64  std::list<std::unique_ptr<IFile>> segments_;
65};
66
67// An IFile that wraps an underlying IFile but limits it to a subsection of that file.
68class FileSegment : public IFile {
69 public:
70  explicit FileSegment(IFile* file, size_t offset, size_t len)
71      : file_(file), offset_(offset), len_(len) {}
72
73  std::unique_ptr<IData> OpenAsData() override;
74
75  const Source& GetSource() const override { return file_->GetSource(); }
76
77 private:
78  DISALLOW_COPY_AND_ASSIGN(FileSegment);
79
80  IFile* file_;
81  size_t offset_;
82  size_t len_;
83};
84
85class IFileCollectionIterator {
86 public:
87  virtual ~IFileCollectionIterator() = default;
88
89  virtual bool HasNext() = 0;
90  virtual IFile* Next() = 0;
91};
92
93// Interface for a collection of files, all of which share a common source. That source may
94// simply be the filesystem, or a ZIP archive.
95class IFileCollection {
96 public:
97  virtual ~IFileCollection() = default;
98
99  virtual IFile* FindFile(const android::StringPiece& path) = 0;
100  virtual std::unique_ptr<IFileCollectionIterator> Iterator() = 0;
101};
102
103}  // namespace io
104}  // namespace aapt
105
106#endif /* AAPT_IO_FILE_H */
107