private async Task <IEnumerable <PackageInfo> > FindPackagesByIdAsyncCore(
string id,
SourceCacheContext cacheContext,
ILogger logger,
CancellationToken cancellationToken)
{
for (var retry = 0; retry < 3; ++retry)
{
var uri = _baseUri + "FindPackagesById()?id='" + id + "'";
var httpSourceCacheContext = HttpSourceCacheContext.Create(cacheContext, retry);
try
{
var results = new List <PackageInfo>();
var uris = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
uris.Add(uri);
var page = 1;
var paging = true;
while (paging)
{
// TODO: Pages for a package ID are cached separately.
// So we will get inaccurate data when a page shrinks.
// However, (1) In most cases the pages grow rather than shrink;
// (2) cache for pages is valid for only 30 min.
// So we decide to leave current logic and observe.
paging = await _httpSource.GetAsync(
new HttpSourceCachedRequest(
uri,
$"list_{id.ToLowerInvariant()}_page{page}",
httpSourceCacheContext)
{
AcceptHeaderValues =
{
new MediaTypeWithQualityHeaderValue("application/atom+xml"),
new MediaTypeWithQualityHeaderValue("application/xml")
},
EnsureValidContents = stream => HttpStreamValidation.ValidateXml(uri, stream),
MaxTries = 1
},
async httpSourceResult =>
{
if (httpSourceResult.Status == HttpSourceResultStatus.NoContent)
{
// Team city returns 204 when no versions of the package exist
// This should result in an empty list and we should not try to
// read the stream as xml.
return(false);
}
var doc = await V2FeedParser.LoadXmlAsync(httpSourceResult.Stream);
var result = doc.Root
.Elements(_xnameEntry)
.Select(x => BuildModel(id, x))
.Where(x => x != null);
results.AddRange(result);
// Find the next url for continuation
var nextUri = V2FeedParser.GetNextUrl(doc);
// Stop if there's nothing else to GET
if (string.IsNullOrEmpty(nextUri))
{
return(false);
}
// check for any duplicate url and error out
if (!uris.Add(nextUri))
{
throw new FatalProtocolException(string.Format(
CultureInfo.CurrentCulture,
Strings.Protocol_duplicateUri,
nextUri));
}
uri = nextUri;
page++;
return(true);
},
logger,
cancellationToken);
}
return(results);
}
catch (Exception ex) when(retry < 2)
{
var message = string.Format(CultureInfo.CurrentCulture, Strings.Log_RetryingFindPackagesById, nameof(FindPackagesByIdAsyncCore), uri)
+ Environment.NewLine
+ ExceptionUtilities.DisplayMessage(ex);
logger.LogMinimal(message);
}
catch (Exception ex) when(retry == 2)
{
var message = string.Format(
CultureInfo.CurrentCulture,
Strings.Log_FailedToRetrievePackage,
id,
uri);
throw new FatalProtocolException(message, ex);
}
}
return(null);
}
internal async Task <XDocument> LoadXmlAsync(
string uri,
string cacheKey,
bool ignoreNotFounds,
SourceCacheContext sourceCacheContext,
ILogger log,
CancellationToken token)
{
if (cacheKey != null && sourceCacheContext != null)
{
var httpSourceCacheContext = HttpSourceCacheContext.Create(sourceCacheContext, 0);
try
{
return(await _httpSource.GetAsync(
new HttpSourceCachedRequest(
uri,
cacheKey,
httpSourceCacheContext)
{
AcceptHeaderValues =
{
new MediaTypeWithQualityHeaderValue("application/atom+xml"),
new MediaTypeWithQualityHeaderValue("application/xml")
},
EnsureValidContents = stream => HttpStreamValidation.ValidateXml(uri, stream),
MaxTries = 1,
IgnoreNotFounds = ignoreNotFounds
},
async response =>
{
if (ignoreNotFounds && response.Status == HttpSourceResultStatus.NotFound)
{
// Treat "404 Not Found" as an empty response.
return null;
}
else if (response.Status == HttpSourceResultStatus.NoContent)
{
// Always treat "204 No Content" as exactly that.
return null;
}
else
{
return await LoadXmlAsync(response.Stream, token);
}
},
log,
token));
}
catch (Exception ex)
{
var message = string.Format(
CultureInfo.CurrentCulture,
Strings.Log_FailedToFetchV2FeedHttp,
uri,
ex.Message);
throw new FatalProtocolException(message, ex);
}
}
else
{
// return results without httpCache
return(await _httpSource.ProcessResponseAsync(
new HttpSourceRequest(
() =>
{
var request = HttpRequestMessageFactory.Create(HttpMethod.Get, uri, log);
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/atom+xml"));
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/xml"));
return request;
})
{
IsRetry = true
},
async response =>
{
if (response.StatusCode == HttpStatusCode.OK)
{
var networkStream = await response.Content.ReadAsStreamAsync();
return await LoadXmlAsync(networkStream, token);
}
else if (ignoreNotFounds && response.StatusCode == HttpStatusCode.NotFound)
{
// Treat "404 Not Found" as an empty response.
return null;
}
else if (response.StatusCode == HttpStatusCode.NoContent)
{
// Always treat "204 No Content" as exactly that.
return null;
}
else
{
throw new FatalProtocolException(string.Format(
CultureInfo.CurrentCulture,
Strings.Log_FailedToFetchV2Feed,
uri,
(int)response.StatusCode,
response.ReasonPhrase));
}
},
sourceCacheContext,
log,
token));
}
}