root / trunk / Pithos.Network / RestClient.cs @ 8f44fd3a
History | View | Annotate | Download (21.3 kB)
1 |
#region |
---|---|
2 |
/* ----------------------------------------------------------------------- |
3 |
* <copyright file="RestClient.cs" company="GRNet"> |
4 |
* |
5 |
* Copyright 2011-2012 GRNET S.A. All rights reserved. |
6 |
* |
7 |
* Redistribution and use in source and binary forms, with or |
8 |
* without modification, are permitted provided that the following |
9 |
* conditions are met: |
10 |
* |
11 |
* 1. Redistributions of source code must retain the above |
12 |
* copyright notice, this list of conditions and the following |
13 |
* disclaimer. |
14 |
* |
15 |
* 2. Redistributions in binary form must reproduce the above |
16 |
* copyright notice, this list of conditions and the following |
17 |
* disclaimer in the documentation and/or other materials |
18 |
* provided with the distribution. |
19 |
* |
20 |
* |
21 |
* THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS |
22 |
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
23 |
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
24 |
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR |
25 |
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
26 |
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
27 |
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
28 |
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
29 |
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
30 |
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
31 |
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
32 |
* POSSIBILITY OF SUCH DAMAGE. |
33 |
* |
34 |
* The views and conclusions contained in the software and |
35 |
* documentation are those of the authors and should not be |
36 |
* interpreted as representing official policies, either expressed |
37 |
* or implied, of GRNET S.A. |
38 |
* </copyright> |
39 |
* ----------------------------------------------------------------------- |
40 |
*/ |
41 |
#endregion |
42 |
using System.Collections.Specialized; |
43 |
using System.Diagnostics; |
44 |
using System.Diagnostics.Contracts; |
45 |
using System.IO; |
46 |
using System.Net; |
47 |
using System.Reflection; |
48 |
using System.Runtime.Serialization; |
49 |
using System.Threading.Tasks; |
50 |
using log4net; |
51 |
|
52 |
|
53 |
namespace Pithos.Network |
54 |
{ |
55 |
using System; |
56 |
using System.Collections.Generic; |
57 |
using System.Linq; |
58 |
using System.Text; |
59 |
|
60 |
/// <summary> |
61 |
/// TODO: Update summary. |
62 |
/// </summary> |
63 |
public class RestClient:WebClient |
64 |
{ |
65 |
private static readonly ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); |
66 |
|
67 |
public int Timeout { get; set; } |
68 |
|
69 |
public bool TimedOut { get; set; } |
70 |
|
71 |
public HttpStatusCode StatusCode { get; private set; } |
72 |
|
73 |
public string StatusDescription { get; set; } |
74 |
|
75 |
public long? RangeFrom { get; set; } |
76 |
public long? RangeTo { get; set; } |
77 |
|
78 |
public int Retries { get; set; } |
79 |
|
80 |
private readonly Dictionary<string, string> _parameters=new Dictionary<string, string>(); |
81 |
public Dictionary<string, string> Parameters |
82 |
{ |
83 |
get |
84 |
{ |
85 |
Contract.Ensures(_parameters!=null); |
86 |
return _parameters; |
87 |
} |
88 |
} |
89 |
|
90 |
|
91 |
[ContractInvariantMethod] |
92 |
private void Invariants() |
93 |
{ |
94 |
Contract.Invariant(Headers!=null); |
95 |
} |
96 |
|
97 |
public RestClient():base() |
98 |
{ |
99 |
//The maximum error response must be large because missing server hashes are return as a Conflivt (409) error response |
100 |
//Any value above 2^21-1 will result in an empty response. |
101 |
//-1 essentially ignores the maximum length |
102 |
HttpWebRequest.DefaultMaximumErrorResponseLength = -1; |
103 |
} |
104 |
|
105 |
|
106 |
public RestClient(RestClient other) |
107 |
: base() |
108 |
{ |
109 |
if (other==null) |
110 |
//Log.ErrorFormat("[ERROR] No parameters provided to the rest client. \n{0}\n", other); |
111 |
throw new ArgumentNullException("other"); |
112 |
Contract.EndContractBlock(); |
113 |
|
114 |
//The maximum error response must be large because missing server hashes are return as a Conflivt (409) error response |
115 |
//Any value above 2^21-1 will result in an empty response. |
116 |
//-1 essentially ignores the maximum length |
117 |
HttpWebRequest.DefaultMaximumErrorResponseLength = -1; |
118 |
|
119 |
CopyHeaders(other); |
120 |
Timeout = other.Timeout; |
121 |
Retries = other.Retries; |
122 |
BaseAddress = other.BaseAddress; |
123 |
|
124 |
foreach (var parameter in other.Parameters) |
125 |
{ |
126 |
Parameters.Add(parameter.Key,parameter.Value); |
127 |
} |
128 |
|
129 |
this.Proxy = other.Proxy; |
130 |
} |
131 |
|
132 |
|
133 |
protected override WebRequest GetWebRequest(Uri address) |
134 |
{ |
135 |
TimedOut = false; |
136 |
var webRequest = base.GetWebRequest(address); |
137 |
var request = (HttpWebRequest)webRequest; |
138 |
request.ServicePoint.ConnectionLimit = 50; |
139 |
if (IfModifiedSince.HasValue) |
140 |
request.IfModifiedSince = IfModifiedSince.Value; |
141 |
request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip; |
142 |
if(Timeout>0) |
143 |
request.Timeout = Timeout; |
144 |
|
145 |
if (RangeFrom.HasValue) |
146 |
{ |
147 |
if (RangeTo.HasValue) |
148 |
request.AddRange(RangeFrom.Value, RangeTo.Value); |
149 |
else |
150 |
request.AddRange(RangeFrom.Value); |
151 |
} |
152 |
return request; |
153 |
} |
154 |
|
155 |
public DateTime? IfModifiedSince { get; set; } |
156 |
|
157 |
//Asynchronous version |
158 |
protected override WebResponse GetWebResponse(WebRequest request, IAsyncResult result) |
159 |
{ |
160 |
Log.InfoFormat("[{0}] {1}", request.Method, request.RequestUri); |
161 |
HttpWebResponse response = null; |
162 |
|
163 |
try |
164 |
{ |
165 |
response = (HttpWebResponse)base.GetWebResponse(request, result); |
166 |
} |
167 |
catch (WebException exc) |
168 |
{ |
169 |
if (!TryGetResponse(exc, request,out response)) |
170 |
throw; |
171 |
} |
172 |
|
173 |
StatusCode = response.StatusCode; |
174 |
LastModified = response.LastModified; |
175 |
StatusDescription = response.StatusDescription; |
176 |
return response; |
177 |
|
178 |
} |
179 |
|
180 |
|
181 |
//Synchronous version |
182 |
protected override WebResponse GetWebResponse(WebRequest request) |
183 |
{ |
184 |
HttpWebResponse response = null; |
185 |
try |
186 |
{ |
187 |
Log.InfoFormat("[{0}] {1}",request.Method,request.RequestUri); |
188 |
response = (HttpWebResponse)base.GetWebResponse(request); |
189 |
} |
190 |
catch (WebException exc) |
191 |
{ |
192 |
if (!TryGetResponse(exc, request,out response)) |
193 |
throw; |
194 |
} |
195 |
|
196 |
StatusCode = response.StatusCode; |
197 |
LastModified = response.LastModified; |
198 |
StatusDescription = response.StatusDescription; |
199 |
return response; |
200 |
} |
201 |
|
202 |
private bool TryGetResponse(WebException exc, WebRequest request,out HttpWebResponse response) |
203 |
{ |
204 |
response = null; |
205 |
//Fail on empty response |
206 |
if (exc.Response == null) |
207 |
{ |
208 |
Log.WarnFormat("[{0}] {1} {2}", request.Method, exc.Status, request.RequestUri); |
209 |
return false; |
210 |
} |
211 |
|
212 |
response = (exc.Response as HttpWebResponse); |
213 |
var statusCode = (int)response.StatusCode; |
214 |
//Succeed on allowed status codes |
215 |
if (AllowedStatusCodes.Contains(response.StatusCode)) |
216 |
{ |
217 |
if (Log.IsDebugEnabled) |
218 |
Log.DebugFormat("[{0}] {1} {2}", request.Method, statusCode, request.RequestUri); |
219 |
return true; |
220 |
} |
221 |
|
222 |
Log.WarnFormat("[{0}] {1} {2}", request.Method, statusCode, request.RequestUri); |
223 |
|
224 |
//Does the response have any content to log? |
225 |
if (exc.Response.ContentLength > 0) |
226 |
{ |
227 |
var content = LogContent(exc.Response); |
228 |
Log.ErrorFormat(content); |
229 |
} |
230 |
return false; |
231 |
} |
232 |
|
233 |
private readonly List<HttpStatusCode> _allowedStatusCodes=new List<HttpStatusCode>{HttpStatusCode.NotModified}; |
234 |
|
235 |
public List<HttpStatusCode> AllowedStatusCodes |
236 |
{ |
237 |
get |
238 |
{ |
239 |
return _allowedStatusCodes; |
240 |
} |
241 |
} |
242 |
|
243 |
public DateTime LastModified { get; private set; } |
244 |
|
245 |
private static string LogContent(WebResponse webResponse) |
246 |
{ |
247 |
if (webResponse == null) |
248 |
throw new ArgumentNullException("webResponse"); |
249 |
Contract.EndContractBlock(); |
250 |
|
251 |
//The response stream must be copied to avoid affecting other code by disposing of the |
252 |
//original response stream. |
253 |
var stream = webResponse.GetResponseStream(); |
254 |
using(var memStream=new MemoryStream()) |
255 |
using (var reader = new StreamReader(memStream)) |
256 |
{ |
257 |
stream.CopyTo(memStream); |
258 |
string content = reader.ReadToEnd(); |
259 |
|
260 |
stream.Seek(0,SeekOrigin.Begin); |
261 |
return content; |
262 |
} |
263 |
} |
264 |
|
265 |
public string DownloadStringWithRetry(string address,int retries=0) |
266 |
{ |
267 |
|
268 |
if (address == null) |
269 |
throw new ArgumentNullException("address"); |
270 |
|
271 |
var actualAddress = GetActualAddress(address); |
272 |
|
273 |
TraceStart("GET",actualAddress); |
274 |
|
275 |
var actualRetries = (retries == 0) ? Retries : retries; |
276 |
|
277 |
var uriString = String.Join("/", BaseAddress.TrimEnd('/'), actualAddress); |
278 |
|
279 |
var task = Retry(() => |
280 |
{ |
281 |
var content = base.DownloadString(uriString); |
282 |
|
283 |
if (StatusCode == HttpStatusCode.NoContent) |
284 |
return String.Empty; |
285 |
return content; |
286 |
|
287 |
}, actualRetries); |
288 |
|
289 |
try |
290 |
{ |
291 |
var result = task.Result; |
292 |
return result; |
293 |
|
294 |
} |
295 |
catch (AggregateException exc) |
296 |
{ |
297 |
//If the task fails, propagate the original exception |
298 |
if (exc.InnerException!=null) |
299 |
throw exc.InnerException; |
300 |
throw; |
301 |
} |
302 |
} |
303 |
|
304 |
public void Head(string address,int retries=0) |
305 |
{ |
306 |
AllowedStatusCodes.Add(HttpStatusCode.NotFound); |
307 |
RetryWithoutContent(address, retries, "HEAD"); |
308 |
} |
309 |
|
310 |
public void PutWithRetry(string address, int retries = 0) |
311 |
{ |
312 |
RetryWithoutContent(address, retries, "PUT"); |
313 |
} |
314 |
|
315 |
public void PostWithRetry(string address,string contentType) |
316 |
{ |
317 |
RetryWithoutContent(address, 0, "POST",contentType); |
318 |
} |
319 |
|
320 |
public void DeleteWithRetry(string address,int retries=0) |
321 |
{ |
322 |
RetryWithoutContent(address, retries, "DELETE"); |
323 |
} |
324 |
|
325 |
public string GetHeaderValue(string headerName,bool optional=false) |
326 |
{ |
327 |
if (this.ResponseHeaders==null) |
328 |
throw new InvalidOperationException("ResponseHeaders are null"); |
329 |
Contract.EndContractBlock(); |
330 |
|
331 |
var values=this.ResponseHeaders.GetValues(headerName); |
332 |
if (values != null) |
333 |
return values[0]; |
334 |
|
335 |
if (optional) |
336 |
return null; |
337 |
//A required header was not found |
338 |
throw new WebException(String.Format("The {0} header is missing", headerName)); |
339 |
} |
340 |
|
341 |
public void SetNonEmptyHeaderValue(string headerName, string value) |
342 |
{ |
343 |
if (String.IsNullOrWhiteSpace(value)) |
344 |
return; |
345 |
Headers.Add(headerName,value); |
346 |
} |
347 |
|
348 |
private void RetryWithoutContent(string address, int retries, string method,string contentType=null) |
349 |
{ |
350 |
if (address == null) |
351 |
throw new ArgumentNullException("address"); |
352 |
|
353 |
var actualAddress = GetActualAddress(address); |
354 |
var actualRetries = (retries == 0) ? Retries : retries; |
355 |
|
356 |
var task = Retry(() => |
357 |
{ |
358 |
var uriString = String.Join("/",BaseAddress ,actualAddress); |
359 |
var uri = new Uri(uriString); |
360 |
var request = GetWebRequest(uri); |
361 |
if (contentType!=null) |
362 |
{ |
363 |
request.ContentType = contentType; |
364 |
request.ContentLength = 0; |
365 |
} |
366 |
request.Method = method; |
367 |
if (ResponseHeaders!=null) |
368 |
ResponseHeaders.Clear(); |
369 |
|
370 |
TraceStart(method, uriString); |
371 |
if (method == "PUT") |
372 |
request.ContentLength = 0; |
373 |
|
374 |
//Have to use try/finally instead of using here, because WebClient needs a valid WebResponse object |
375 |
//in order to return response headers |
376 |
var response = (HttpWebResponse)GetWebResponse(request); |
377 |
try |
378 |
{ |
379 |
LastModified = response.LastModified; |
380 |
StatusCode = response.StatusCode; |
381 |
StatusDescription = response.StatusDescription; |
382 |
} |
383 |
finally |
384 |
{ |
385 |
response.Close(); |
386 |
} |
387 |
|
388 |
|
389 |
return 0; |
390 |
}, actualRetries); |
391 |
|
392 |
try |
393 |
{ |
394 |
task.Wait(); |
395 |
} |
396 |
catch (AggregateException ex) |
397 |
{ |
398 |
var exc = ex.InnerException; |
399 |
if (exc is RetryException) |
400 |
{ |
401 |
Log.ErrorFormat("[{0}] RETRY FAILED for {1} after {2} retries",method,address,retries); |
402 |
} |
403 |
else |
404 |
{ |
405 |
Log.ErrorFormat("[{0}] FAILED for {1} with \n{2}", method, address, exc); |
406 |
} |
407 |
throw exc; |
408 |
|
409 |
} |
410 |
catch(Exception ex) |
411 |
{ |
412 |
Log.ErrorFormat("[{0}] FAILED for {1} with \n{2}", method, address, ex); |
413 |
throw; |
414 |
} |
415 |
} |
416 |
|
417 |
private static void TraceStart(string method, string actualAddress) |
418 |
{ |
419 |
Log.InfoFormat("[{0}] {1} {2}", method, DateTime.Now, actualAddress); |
420 |
} |
421 |
|
422 |
private string GetActualAddress(string address) |
423 |
{ |
424 |
if (Parameters.Count == 0) |
425 |
return address; |
426 |
var addressBuilder=new StringBuilder(address); |
427 |
|
428 |
bool isFirst = true; |
429 |
foreach (var parameter in Parameters) |
430 |
{ |
431 |
if(isFirst) |
432 |
addressBuilder.AppendFormat("?{0}={1}", parameter.Key, parameter.Value); |
433 |
else |
434 |
addressBuilder.AppendFormat("&{0}={1}", parameter.Key, parameter.Value); |
435 |
isFirst = false; |
436 |
} |
437 |
return addressBuilder.ToString(); |
438 |
} |
439 |
|
440 |
public string DownloadStringWithRetry(Uri address,int retries=0) |
441 |
{ |
442 |
if (address == null) |
443 |
throw new ArgumentNullException("address"); |
444 |
|
445 |
var actualRetries = (retries == 0) ? Retries : retries; |
446 |
var task = Retry(() => |
447 |
{ |
448 |
var content = base.DownloadString(address); |
449 |
|
450 |
if (StatusCode == HttpStatusCode.NoContent) |
451 |
return String.Empty; |
452 |
return content; |
453 |
|
454 |
}, actualRetries); |
455 |
|
456 |
var result = task.Result; |
457 |
return result; |
458 |
} |
459 |
|
460 |
|
461 |
/// <summary> |
462 |
/// Copies headers from another RestClient |
463 |
/// </summary> |
464 |
/// <param name="source">The RestClient from which the headers are copied</param> |
465 |
public void CopyHeaders(RestClient source) |
466 |
{ |
467 |
if (source == null) |
468 |
throw new ArgumentNullException("source", "source can't be null"); |
469 |
Contract.EndContractBlock(); |
470 |
//The Headers getter initializes the property, it is never null |
471 |
Contract.Assume(Headers!=null); |
472 |
|
473 |
CopyHeaders(source.Headers,Headers); |
474 |
} |
475 |
|
476 |
/// <summary> |
477 |
/// Copies headers from one header collection to another |
478 |
/// </summary> |
479 |
/// <param name="source">The source collection from which the headers are copied</param> |
480 |
/// <param name="target">The target collection to which the headers are copied</param> |
481 |
public static void CopyHeaders(WebHeaderCollection source,WebHeaderCollection target) |
482 |
{ |
483 |
if (source == null) |
484 |
throw new ArgumentNullException("source", "source can't be null"); |
485 |
if (target == null) |
486 |
throw new ArgumentNullException("target", "target can't be null"); |
487 |
Contract.EndContractBlock(); |
488 |
|
489 |
for (int i = 0; i < source.Count; i++) |
490 |
{ |
491 |
target.Add(source.GetKey(i), source[i]); |
492 |
} |
493 |
} |
494 |
|
495 |
public void AssertStatusOK(string message) |
496 |
{ |
497 |
if (StatusCode >= HttpStatusCode.BadRequest) |
498 |
throw new WebException(String.Format("{0} with code {1} - {2}", message, StatusCode, StatusDescription)); |
499 |
} |
500 |
|
501 |
|
502 |
private Task<T> Retry<T>(Func<T> original, int retryCount, TaskCompletionSource<T> tcs = null) |
503 |
{ |
504 |
if (original==null) |
505 |
throw new ArgumentNullException("original"); |
506 |
Contract.EndContractBlock(); |
507 |
|
508 |
if (tcs == null) |
509 |
tcs = new TaskCompletionSource<T>(); |
510 |
Task.Factory.StartNew(original).ContinueWith(_original => |
511 |
{ |
512 |
if (!_original.IsFaulted) |
513 |
tcs.SetFromTask(_original); |
514 |
else |
515 |
{ |
516 |
var e = _original.Exception.InnerException; |
517 |
var we = (e as WebException); |
518 |
if (we==null) |
519 |
tcs.SetException(e); |
520 |
else |
521 |
{ |
522 |
var statusCode = GetStatusCode(we); |
523 |
|
524 |
//Return null for 404 |
525 |
if (statusCode == HttpStatusCode.NotFound) |
526 |
tcs.SetResult(default(T)); |
527 |
//Retry for timeouts and service unavailable |
528 |
else if (we.Status == WebExceptionStatus.Timeout || |
529 |
(we.Status == WebExceptionStatus.ProtocolError && statusCode == HttpStatusCode.ServiceUnavailable)) |
530 |
{ |
531 |
TimedOut = true; |
532 |
if (retryCount == 0) |
533 |
{ |
534 |
Log.ErrorFormat("[ERROR] Timed out too many times. \n{0}\n",e); |
535 |
tcs.SetException(new RetryException("Timed out too many times.", e)); |
536 |
} |
537 |
else |
538 |
{ |
539 |
Log.ErrorFormat( |
540 |
"[RETRY] Timed out after {0} ms. Will retry {1} more times\n{2}", Timeout, |
541 |
retryCount, e); |
542 |
Retry(original, retryCount - 1, tcs); |
543 |
} |
544 |
} |
545 |
else |
546 |
tcs.SetException(e); |
547 |
} |
548 |
}; |
549 |
}); |
550 |
return tcs.Task; |
551 |
} |
552 |
|
553 |
private HttpStatusCode GetStatusCode(WebException we) |
554 |
{ |
555 |
if (we==null) |
556 |
throw new ArgumentNullException("we"); |
557 |
var statusCode = HttpStatusCode.RequestTimeout; |
558 |
if (we.Response != null) |
559 |
{ |
560 |
statusCode = ((HttpWebResponse) we.Response).StatusCode; |
561 |
this.StatusCode = statusCode; |
562 |
} |
563 |
return statusCode; |
564 |
} |
565 |
|
566 |
public UriBuilder GetAddressBuilder(string container, string objectName) |
567 |
{ |
568 |
var builder = new UriBuilder(String.Join("/", BaseAddress, container, objectName)); |
569 |
return builder; |
570 |
} |
571 |
|
572 |
public Dictionary<string, string> GetMeta(string metaPrefix) |
573 |
{ |
574 |
if (String.IsNullOrWhiteSpace(metaPrefix)) |
575 |
throw new ArgumentNullException("metaPrefix"); |
576 |
Contract.EndContractBlock(); |
577 |
|
578 |
var keys = ResponseHeaders.AllKeys.AsQueryable(); |
579 |
var dict = (from key in keys |
580 |
where key.StartsWith(metaPrefix) |
581 |
let name = key.Substring(metaPrefix.Length) |
582 |
select new { Name = name, Value = ResponseHeaders[key] }) |
583 |
.ToDictionary(t => t.Name, t => t.Value); |
584 |
return dict; |
585 |
} |
586 |
|
587 |
} |
588 |
|
589 |
public class RetryException:Exception |
590 |
{ |
591 |
public RetryException() |
592 |
:base() |
593 |
{ |
594 |
|
595 |
} |
596 |
|
597 |
public RetryException(string message) |
598 |
:base(message) |
599 |
{ |
600 |
|
601 |
} |
602 |
|
603 |
public RetryException(string message,Exception innerException) |
604 |
:base(message,innerException) |
605 |
{ |
606 |
|
607 |
} |
608 |
|
609 |
public RetryException(SerializationInfo info,StreamingContext context) |
610 |
:base(info,context) |
611 |
{ |
612 |
|
613 |
} |
614 |
} |
615 |
} |