forked from chronoxor/NetCoreServer
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathFileCache.cs
More file actions
476 lines (399 loc) · 16.8 KB
/
Copy pathFileCache.cs
File metadata and controls
476 lines (399 loc) · 16.8 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading;
using System.Web;
namespace NetCoreServer
{
/// <summary>
/// File cache is used to cache files in memory with optional timeouts.
/// FileSystemWatcher is used to monitor file system changes in cached
/// directories.
/// </summary>
/// <remarks>Thread-safe.</remarks>
public class FileCache : IDisposable
{
public delegate bool InsertHandler(FileCache cache, string key, byte[] value, TimeSpan timeout);
#region Cache items access
/// <summary>
/// Is the file cache empty?
/// </summary>
public bool Empty => _entriesByKey.Count == 0;
/// <summary>
/// Get the file cache size
/// </summary>
public int Size => _entriesByKey.Count;
/// <summary>
/// Add a new cache value with the given timeout into the file cache
/// </summary>
/// <param name="key">Key to add</param>
/// <param name="value">Value to add</param>
/// <param name="timeout">Cache timeout (default is 0 - no timeout)</param>
/// <returns>'true' if the cache value was added, 'false' if the given key was not added</returns>
public bool Add(string key, byte[] value, TimeSpan timeout = new TimeSpan())
{
using (new WriteLock(_lockEx))
{
// Try to find and remove the previous key
_entriesByKey.Remove(key);
// Update the cache entry
_entriesByKey.Add(key, new MemCacheEntry(value, timeout));
return true;
}
}
/// <summary>
/// Try to find the cache value by the given key
/// </summary>
/// <param name="key">Key to find</param>
/// <returns>'true' and cache value if the cache value was found, 'false' if the given key was not found</returns>
public (bool, byte[]) Find(string key)
{
using (new ReadLock(_lockEx))
{
// Try to find the given key
if (!_entriesByKey.TryGetValue(key, out var cacheValue))
return (false, new byte[0]);
return (true, cacheValue.Value);
}
}
/// <summary>
/// Remove the cache value with the given key from the file cache
/// </summary>
/// <param name="key">Key to remove</param>
/// <returns>'true' if the cache value was removed, 'false' if the given key was not found</returns>
public bool Remove(string key)
{
using (new WriteLock(_lockEx))
{
return _entriesByKey.Remove(key);
}
}
#endregion
#region Cache management methods
/// <summary>
/// Insert a new cache path with the given timeout into the file cache
/// </summary>
/// <param name="path">Path to insert</param>
/// <param name="prefix">Cache prefix (default is "/")</param>
/// <param name="filter">Cache filter (default is "*.*")</param>
/// <param name="timeout">Cache timeout (default is 0 - no timeout)</param>
/// <param name="handler">Cache insert handler (default is 'return cache.Add(key, value, timeout)')</param>
/// <returns>'true' if the cache path was setup, 'false' if failed to setup the cache path</returns>
public bool InsertPath(string path, string prefix = "/", string filter = "*.*", TimeSpan timeout = new TimeSpan(), InsertHandler handler = null)
{
handler ??= (FileCache cache, string key, byte[] value, TimeSpan timespan) => cache.Add(key, value, timespan);
// Try to find and remove the previous path
RemovePathInternal(path);
using (new WriteLock(_lockEx))
{
// Add the given path to the cache
_pathsByKey.Add(path, new FileCacheEntry(this, prefix, path, filter, handler, timeout));
// Create entries by path map
_entriesByPath[path] = new HashSet<string>();
}
// Insert the cache path
if (!InsertPathInternal(path, path, prefix, timeout, handler))
return false;
return true;
}
/// <summary>
/// Try to find the cache path
/// </summary>
/// <param name="path">Path to find</param>
/// <returns>'true' if the cache path was found, 'false' if the given path was not found</returns>
public bool FindPath(string path)
{
using (new ReadLock(_lockEx))
{
// Try to find the given key
return _pathsByKey.ContainsKey(path);
}
}
/// <summary>
/// Remove the cache path from the file cache
/// </summary>
/// <param name="path">Path to remove</param>
/// <returns>'true' if the cache path was removed, 'false' if the given path was not found</returns>
public bool RemovePath(string path)
{
return RemovePathInternal(path);
}
/// <summary>
/// Clear the memory cache
/// </summary>
public void Clear()
{
using (new WriteLock(_lockEx))
{
// Stop all file system watchers
foreach (var fileCacheEntry in _pathsByKey)
fileCacheEntry.Value.StopWatcher();
// Clear all cache entries
_entriesByKey.Clear();
_entriesByPath.Clear();
_pathsByKey.Clear();
}
}
#endregion
#region Cache implementation
private readonly ReaderWriterLockSlim _lockEx = new ReaderWriterLockSlim();
private Dictionary<string, MemCacheEntry> _entriesByKey = new Dictionary<string, MemCacheEntry>();
private Dictionary<string, HashSet<string>> _entriesByPath = new Dictionary<string, HashSet<string>>();
private Dictionary<string, FileCacheEntry> _pathsByKey = new Dictionary<string, FileCacheEntry>();
private class MemCacheEntry
{
private readonly byte[] _value;
private readonly TimeSpan _timespan;
public byte[] Value => _value;
public TimeSpan Timespan => _timespan;
public MemCacheEntry(byte[] value, TimeSpan timespan = new TimeSpan())
{
_value = value;
_timespan = timespan;
}
public MemCacheEntry(string value, TimeSpan timespan = new TimeSpan())
{
_value = Encoding.UTF8.GetBytes(value);
_timespan = timespan;
}
};
private class FileCacheEntry
{
private readonly string _prefix;
private readonly string _path;
private readonly InsertHandler _handler;
private readonly TimeSpan _timespan;
private readonly FileSystemWatcher _watcher;
public FileCacheEntry(FileCache cache, string prefix, string path, string filter, InsertHandler handler, TimeSpan timespan)
{
_prefix = prefix.Replace('\\', '/').RemoveSuffix('/');
_path = path.Replace('\\', '/').RemoveSuffix('/');
_handler = handler;
_timespan = timespan;
_watcher = new FileSystemWatcher();
// Start the filesystem watcher
StartWatcher(cache, path, filter);
}
private void StartWatcher(FileCache cache, string path, string filter)
{
FileCacheEntry entry = this;
// Initialize a new filesystem watcher
_watcher.Created += (sender, e) => OnCreated(sender, e, cache, entry);
_watcher.Changed += (sender, e) => OnChanged(sender, e, cache, entry);
_watcher.Deleted += (sender, e) => OnDeleted(sender, e, cache, entry);
_watcher.Renamed += (sender, e) => OnRenamed(sender, e, cache, entry);
_watcher.Path = path;
_watcher.IncludeSubdirectories = true;
_watcher.Filter = filter;
_watcher.NotifyFilter = NotifyFilters.FileName | NotifyFilters.LastWrite;
_watcher.EnableRaisingEvents = true;
}
public void StopWatcher()
{
_watcher.Dispose();
}
private static bool IsDirectory(string path)
{
try
{
// Skip directory updates
if (File.GetAttributes(path).HasFlag(FileAttributes.Directory))
return true;
}
catch (Exception) {}
return false;
}
private static void OnCreated(object sender, FileSystemEventArgs e, FileCache cache, FileCacheEntry entry)
{
var key = e.FullPath.Replace('\\', '/').Replace(entry._path, entry._prefix).RemoveSuffix('/');
var file = e.FullPath.Replace('\\', '/').RemoveSuffix('/');
// Skip missing files
if (!File.Exists(file))
return;
// Skip directory updates
if (IsDirectory(file))
return;
cache.InsertFileInternal(entry._path, file, key, entry._timespan, entry._handler);
}
private static void OnChanged(object sender, FileSystemEventArgs e, FileCache cache, FileCacheEntry entry)
{
if (e.ChangeType != WatcherChangeTypes.Changed)
return;
var key = e.FullPath.Replace('\\', '/').Replace(entry._path, entry._prefix).RemoveSuffix('/');
var file = e.FullPath.Replace('\\', '/').RemoveSuffix('/');
// Skip missing files
if (!File.Exists(file))
return;
// Skip directory updates
if (IsDirectory(file))
return;
cache.InsertFileInternal(entry._path, file, key, entry._timespan, entry._handler);
}
private static void OnDeleted(object sender, FileSystemEventArgs e, FileCache cache, FileCacheEntry entry)
{
var key = e.FullPath.Replace('\\', '/').Replace(entry._path, entry._prefix).RemoveSuffix('/');
var file = e.FullPath.Replace('\\', '/').RemoveSuffix('/');
cache.RemoveFileInternal(entry._path, key);
}
private static void OnRenamed(object sender, RenamedEventArgs e, FileCache cache, FileCacheEntry entry)
{
var oldKey = e.OldFullPath.Replace('\\', '/').Replace(entry._path, entry._prefix).RemoveSuffix('/');
var oldFile = e.OldFullPath.Replace('\\', '/').RemoveSuffix('/');
var newKey = e.FullPath.Replace('\\', '/').Replace(entry._path, entry._prefix).RemoveSuffix('/');
var newFile = e.FullPath.Replace('\\', '/').RemoveSuffix('/');
// Skip missing files
if (!File.Exists(newFile))
return;
// Skip directory updates
if (IsDirectory(newFile))
return;
cache.RemoveFileInternal(entry._path, oldKey);
cache.InsertFileInternal(entry._path, newFile, newKey, entry._timespan, entry._handler);
}
};
private bool InsertFileInternal(string path, string file, string key, TimeSpan timeout, InsertHandler handler)
{
try
{
// Load the cache file content
var content = File.ReadAllBytes(file);
if (!handler(this, key, content, timeout))
return false;
using (new WriteLock(_lockEx))
{
// Update entries by path map
_entriesByPath[path].Add(key);
}
return true;
}
catch (Exception) { return false; }
}
private bool RemoveFileInternal(string path, string key)
{
try
{
using (new WriteLock(_lockEx))
{
// Update entries by path map
_entriesByPath[path].Remove(key);
}
return Remove(key);
}
catch (Exception) { return false; }
}
private bool InsertPathInternal(string root, string path, string prefix, TimeSpan timeout, InsertHandler handler)
{
try
{
// Iterate through all directory entries
foreach (var item in Directory.GetDirectories(path))
{
string key = prefix + "/" + HttpUtility.UrlDecode(Path.GetFileName(item));
// Recursively insert sub-directory
if (!InsertPathInternal(root, item, key, timeout, handler))
return false;
}
foreach (var item in Directory.GetFiles(path))
{
string key = prefix + "/" + HttpUtility.UrlDecode(Path.GetFileName(item));
// Insert file into the cache
if (!InsertFileInternal(root, item, key, timeout, handler))
return false;
}
return true;
}
catch (Exception) { return false; }
}
private bool RemovePathInternal(string path)
{
using (new WriteLock(_lockEx))
{
// Try to find the given path
if (!_pathsByKey.TryGetValue(path, out var cacheValue))
return false;
// Stop the file system watcher
cacheValue.StopWatcher();
// Remove path entries
foreach (var entryKey in _entriesByPath[path])
_entriesByKey.Remove(entryKey);
_entriesByPath.Remove(path);
// Remove cache path
_pathsByKey.Remove(path);
return true;
}
}
#endregion
#region IDisposable implementation
// Disposed flag.
private bool _disposed;
// Implement IDisposable.
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposingManagedResources)
{
// The idea here is that Dispose(Boolean) knows whether it is
// being called to do explicit cleanup (the Boolean is true)
// versus being called due to a garbage collection (the Boolean
// is false). This distinction is useful because, when being
// disposed explicitly, the Dispose(Boolean) method can safely
// execute code using reference type fields that refer to other
// objects knowing for sure that these other objects have not been
// finalized or disposed of yet. When the Boolean is false,
// the Dispose(Boolean) method should not execute code that
// refer to reference type fields because those objects may
// have already been finalized."
if (!_disposed)
{
if (disposingManagedResources)
{
// Dispose managed resources here...
Clear();
}
// Dispose unmanaged resources here...
// Set large fields to null here...
// Mark as disposed.
_disposed = true;
}
}
#endregion
}
/// <summary>
/// Disposable lock class performs exit action on dispose operation.
/// </summary>
public class DisposableLock : IDisposable
{
private readonly Action _exitLock;
public DisposableLock(Action exitLock)
{
_exitLock = exitLock;
}
public void Dispose()
{
_exitLock();
}
}
/// <summary>
/// Read lock class enters read lock on construction and performs exit read lock on dispose.
/// </summary>
public class ReadLock : DisposableLock
{
public ReadLock(ReaderWriterLockSlim locker) : base(locker.ExitReadLock)
{
locker.EnterReadLock();
}
}
/// <summary>
/// Write lock class enters write lock on construction and performs exit write lock on dispose.
/// </summary>
public class WriteLock : DisposableLock
{
public WriteLock(ReaderWriterLockSlim locker) : base(locker.ExitWriteLock)
{
locker.EnterWriteLock();
}
}
}