1 /*
2  * Copyright (c) 2024 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef CORE__IO__DEV__FILEMONITOR_H
17 #define CORE__IO__DEV__FILEMONITOR_H
18 
19 #include <cstdint>
20 
21 #include <base/containers/string.h>
22 #include <base/containers/string_view.h>
23 #include <base/containers/unordered_map.h>
24 #include <base/containers/vector.h>
25 #include <base/namespace.h>
26 #include <core/namespace.h>
27 
28 CORE_BEGIN_NAMESPACE()
29 class IFileManager;
30 class FileMonitor {
31 public:
32     explicit FileMonitor(IFileManager&);
33     /** Adds path to watch list, the monitor will recursively monitor all files in this directory and it's subtree.
34      * @param path Path to directory that is being monitored, such as 'file://x:/images/' or 'file://./images' or
35      * 'shaders://'.
36      * @return True if path is succesfully added to watch list, otherwise false.
37      */
38     bool AddPath(BASE_NS::string_view path);
39 
40     /** Removes path from watch list, the monitor will no longer watch files in this directory or it's subtree.
41      * @param path Path to directory to be no longer monitored.
42      * @return True if the watch is successfully removed, otherwise false.
43      */
44     bool RemovePath(BASE_NS::string_view path);
45 
46     /** Scans for file modifications since last call to this function.
47      * @param added List of files that were added.
48      * @param removed List of files that were removed.
49      * @param modified List of files that were modified.
50      */
51     void ScanModifications(BASE_NS::vector<BASE_NS::string>& added, BASE_NS::vector<BASE_NS::string>& removed,
52         BASE_NS::vector<BASE_NS::string>& modified);
53 
54     /** Get list of currently monitored files.
55      * @return List of monitored files (absolute filepaths).
56      */
57     BASE_NS::vector<BASE_NS::string> GetMonitoredFiles() const;
58 
59 private:
60     struct FileInfo {
61         uint64_t timestamp { 0 };
62         // removed is a file left over from last scan. which means it should be removed.
63         enum {
64             REMOVED = 0,
65             NOCHANGE = 1,
66             MODIFIED = 2,
67             ADDED = 3,
68         } state { REMOVED };
69     };
70 
71     bool IsWatchingDirectory(BASE_NS::string_view path);
72     bool IsWatchingSubDirectory(BASE_NS::string_view path);
73     void RecursivelyCollectAllFiles(BASE_NS::string& path);
74     static void CleanPath(BASE_NS::string_view, BASE_NS::string&);
75 
76     BASE_NS::vector<BASE_NS::string> directories_;
77     BASE_NS::unordered_map<BASE_NS::string, FileInfo> files_;
78     IFileManager& fileManager_;
79     BASE_NS::string pathTmp_;
80 };
81 CORE_END_NAMESPACE()
82 
83 #endif // CORE__IO__DEV__FILEMONITOR_H
84