static void DataInfoFinished(DownloadDataInfo dataInfo)
{
if (dataInfo != null)
{
var userIP = dataInfo.UserId;
var guid = dataInfo.DataId;
RemoveDownloadInfoByDataId(guid);
RefreshUserLimitState(userIP);
}
}
private static bool CheckIfUnmodifiedSince(HttpRequest request, DownloadDataInfo dataInfo)
{
string dateHeader;
DateTime theDate;
bool breturn;
// Checks the If-Unmodified or Unless-Modified-Since header, if
// one of them was sent with the request.
//
// returns true, if the file was not modified since the
// indicated date (RFC 1123 format), or
// if no header was sent,
// returns false, if the file was modified since the indicated date
// Retrieve If-Unmodified-Since Header value from Request (Empty if none is indicated)
dateHeader = RetrieveHeader(request, HTTP_HEADER_IF_UNMODIFIED_SINCE, String.Empty);
if (dateHeader.Equals(String.Empty))
{
// If-Unmodified-Since was not sent, check Unless-Modified-Since...
dateHeader = RetrieveHeader(request, HTTP_HEADER_UNLESS_MODIFIED_SINCE, String.Empty);
}
if (dateHeader.Equals(String.Empty))
{
// No date was indicated,
// so just give this as true
breturn = true;
}
else
{
try
{
// ... to parse the indicated sDate to a datetime value
theDate = DateTime.Parse(dateHeader);
// return true if the file was not modified since the indicated date...
breturn = dataInfo.LastWriteTimeUtc < theDate;
}
catch (Exception)
{
// Converting the indicated date value failed, return false
breturn = false;
}
}
return(breturn);
}
/// <summary>
/// Validating partial request, extracts matched ETag
/// </summary>
/// <returns>true if pertial request is valid</returns>
public static bool ValidatePartialRequest(
HttpRequest request,
DownloadDataInfo dataInfo,
out string matchedETag,
ref int statusCode)
{
matchedETag = null;
if (!(dataInfo.RequestHttpMethod.Equals(HTTP_METHOD_GET) ||
dataInfo.RequestHttpMethod.Equals(HTTP_METHOD_HEAD)))
{
// Currently, only the GET and HEAD methods
// are supported...
statusCode = 501; // Not implemented
return(false);
}
else if (!CheckIfModifiedSince(request, dataInfo))
{
// The entity is still unmodified...
statusCode = 304; // Not Modified
return(false);
}
else if (!CheckIfUnmodifiedSince(request, dataInfo))
{
// The entity was modified since the requested date...
statusCode = 412; // Precondition failed
return(false);
}
else if (!CheckIfMatch(request, dataInfo))
{
// The entity does not match the request...
statusCode = 412; // Precondition failed
return(false);
}
else if (!CheckIfNoneMatch(request, ref statusCode, out matchedETag, dataInfo))
{
// The entity does match the none-match request, the response
// code was set inside the CheckifNoneMatch function
//matchedETag
// valid but content is not required
return(false);
}
else
{
//valid
return(true);
}
}
/// <summary>
/// Adding a new download to the list!
/// </summary>
public static void StartNewDownload(DownloadDataInfo dataInfo, string userIP, int userSpeedLimit = 0)
{
if (userIP == null || dataInfo == null)
{
throw new ArgumentNullException();
}
dataInfo.UserId = userIP;
dataInfo.Finished += DataInfoFinished;
lock (_userDownloadInfo)
{
_userDownloadInfo.Add(new DownloadInfo {
UserIP = userIP, DataInfo = dataInfo, SpeedLimit = userSpeedLimit
});
}
// changing all the downloads speed beglogs to this user
ApplySpeedLimit(userIP, userSpeedLimit);
}
private static bool CheckIfModifiedSince(HttpRequest request, DownloadDataInfo dataInfo)
{
string headerDate;
DateTime theDate;
bool breturn;
// Checks the If-Modified header if it was sent with the request.
//
// returns true, if the file was modified since the
// indicated date (RFC 1123 format), or
// if no header was sent,
// returns false, if the file was not modified since
// the indicated date
// Retrieve If-Modified-Since Header value from Request (Empty if none is indicated)
headerDate = RetrieveHeader(request, HTTP_HEADER_IF_MODIFIED_SINCE, string.Empty);
if (headerDate.Equals(String.Empty))
{
// No If-Modified-Since date was indicated,
// so just give this as true
breturn = true;
}
else
{
try
{
// ... to parse the indicated sDate to a datetime value
theDate = DateTime.Parse(headerDate);
// return true if the file was modified since or at the indicated date...
breturn = (dataInfo.LastWriteTimeUtc >= theDate);
}
catch
{
// Converting the indicated date value failed, return false
breturn = false;
}
}
return(breturn);
}
private static bool CheckIfMatch(HttpRequest request, DownloadDataInfo responseData)
{
string requestHeaderIfMatch;
string[] entityIDs;
bool result = false;
// Checks the If-Match header if it was sent with the request.
//
// returns true if one of the header values matches the file//s entity tag,
// or if no header was sent,
// returns false if a header was sent, but does not match the file.
// Retrieve If-Match Header value from Request (*, meaning any, if none is indicated)
requestHeaderIfMatch = RetrieveHeader(request, HTTP_HEADER_IF_MATCH, "*");
if (requestHeaderIfMatch.Equals("*"))
{
// The server may perform the request as if the
// If-Match header does not exists...
result = true;
}
else
{
// One or more Match IDs where sent by the client software...
entityIDs = requestHeaderIfMatch.Replace("bytes=", "").Split(",".ToCharArray());
// Loop through all entity IDs, finding one
// which matches the current file's ID will
// be enough to satisfy the If-Match
for (int iLoop = entityIDs.GetLowerBound(0); iLoop <= entityIDs.GetUpperBound(0); iLoop++)
{
if (entityIDs[iLoop].Trim().Equals(responseData.EntityTag))
{
result = true;
}
}
}
// return the result...
return(result);
}
private static bool CheckIfNoneMatch(
HttpRequest request,
ref int statusCode,
out string matchedETag,
DownloadDataInfo dataInfo)
{
string requestHeaderIfNoneMatch;
string[] entityIDs;
bool breturn = true;
string sreturn = "";
matchedETag = "";
// Checks the If-None-Match header if it was sent with the request.
//
// returns true if one of the header values matches the file//s entity tag,
// or if "*" was sent,
// returns false if a header was sent, but does not match the file, or
// if no header was sent.
// Retrieve If-None-Match Header value from Request (*, meaning any, if none is indicated)
requestHeaderIfNoneMatch = RetrieveHeader(request, HTTP_HEADER_IF_NONE_MATCH, String.Empty);
if (requestHeaderIfNoneMatch.Equals(String.Empty))
{
// Perform the request normally...
breturn = true;
}
else
{
if (requestHeaderIfNoneMatch.Equals("*"))
{
// The server must not perform the request
statusCode = 412; // Precondition failed
breturn = false;
}
else
{
// One or more Match IDs where sent by the client software...
entityIDs = requestHeaderIfNoneMatch.Replace("bytes=", "").Split(",".ToCharArray());
// Loop through all entity IDs, finding one which
// does not match the current file//s ID will be
// enough to satisfy the If-None-Match
for (int iLoop = entityIDs.GetLowerBound(0); iLoop <= entityIDs.GetUpperBound(0); iLoop++)
{
if (entityIDs[iLoop].Trim().Equals(dataInfo.EntityTag))
{
sreturn = entityIDs[iLoop];
breturn = false;
}
}
if (!breturn)
{
// One of the requested entities matches the current file's tag,
//objResponse.AppendHeader("ETag", sreturn);
matchedETag = sreturn;
statusCode = 304; // Not Modified
}
}
}
// return the result...
return(breturn);
}
public DownloadProcess(DownloadDataInfo dataInfo)
{
_dataInfo = dataInfo;
}
