private static bool CheckIfUnmodifiedSince(HttpRequest request, ResumableResponseData responseData)
{
string sDate;
DateTime dDate;
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)
sDate = RetrieveHeader(request, HTTP_HEADER_IF_UNMODIFIED_SINCE, String.Empty);
if (sDate.Equals(String.Empty))
{
// If-Unmodified-Since was not sent, check Unless-Modified-Since...
sDate = RetrieveHeader(request, HTTP_HEADER_UNLESS_MODIFIED_SINCE, String.Empty);
}
if (sDate.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
dDate = DateTime.Parse(sDate);
// return true if the file was not modified since the indicated date...
breturn = responseData.LastWriteTimeUTC < DateTime.Parse(sDate);
}
catch (Exception)
{
// Converting the indicated date value failed, return false
breturn = false;
}
}
return(breturn);
}
public static bool ValidatePartialRequest(HttpRequest request, ResumableResponseData responseData, out string matchedETag, ref int statusCode)
{
const string HTTP_METHOD_GET = "GET";
const string HTTP_METHOD_HEAD = "HEAD";
matchedETag = null;
if (!(responseData.HttpMethod.Equals(HTTP_METHOD_GET) ||
responseData.HttpMethod.Equals(HTTP_METHOD_HEAD)))
{
// Currently, only the GET and HEAD methods
// are supported...
statusCode = 501; // Not implemented
return(false);
}
else if (!CheckIfModifiedSince(request, responseData))
{
// The entity is still unmodified...
statusCode = 304; // Not Modified
return(false);
}
else if (!CheckIfUnmodifiedSince(request, responseData))
{
// The entity was modified since the requested date...
statusCode = 412; // Precondition failed
return(false);
}
else if (!CheckIfMatch(request, responseData))
{
// The entity does not match the request...
statusCode = 412; // Precondition failed
return(false);
}
else if (!CheckIfNoneMatch(request, ref statusCode, out matchedETag, responseData))
{
// 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);
}
}
private static bool CheckIfModifiedSince(HttpRequest request, ResumableResponseData responseData)
{
string sDate;
DateTime dDate;
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)
sDate = RetrieveHeader(request, HTTP_HEADER_IF_MODIFIED_SINCE, string.Empty);
if (sDate.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
dDate = DateTime.Parse(sDate);
// return true if the file was modified since or at the indicated date...
breturn = (responseData.LastWriteTimeUTC >= DateTime.Parse(sDate));
}
catch
{
// Converting the indicated date value failed, return false
breturn = false;
}
}
return(breturn);
}
private static bool CheckIfMatch(HttpRequest request, ResumableResponseData responseData)
{
string sRequestHeaderIfMatch;
string[] sEntityIDs;
bool breturn = 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)
sRequestHeaderIfMatch = RetrieveHeader(request, HTTP_HEADER_IF_MATCH, "*");
if (sRequestHeaderIfMatch.Equals("*"))
{
// The server may perform the request as if the
// If-Match header does not exists...
breturn = true;
}
else
{
// One or more Match IDs where sent by the client software...
sEntityIDs = sRequestHeaderIfMatch.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 = sEntityIDs.GetLowerBound(0); iLoop <= sEntityIDs.GetUpperBound(0); iLoop++)
{
if (sEntityIDs[iLoop].Trim().Equals(responseData.EntityTag))
{
breturn = true;
}
}
}
// return the result...
return(breturn);
}
public ResumableResponse(ResumableResponseData responseData)
{
_responseData = responseData;
}
public ResumableResponse(ResumableResponseData responseData)
{
_responseData = responseData;
}
private static bool CheckIfNoneMatch(HttpRequest request, ref int statusCode, out string matchedETag, ResumableResponseData responseData)
{
string sRequestHeaderIfNoneMatch;
string[] sEntityIDs;
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)
sRequestHeaderIfNoneMatch = RetrieveHeader(request, HTTP_HEADER_IF_NONE_MATCH, String.Empty);
if (sRequestHeaderIfNoneMatch.Equals(String.Empty))
{
// Perform the request normally...
breturn = true;
}
else
{
if (sRequestHeaderIfNoneMatch.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...
sEntityIDs = sRequestHeaderIfNoneMatch.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 = sEntityIDs.GetLowerBound(0); iLoop <= sEntityIDs.GetUpperBound(0); iLoop++)
{
if (sEntityIDs[iLoop].Trim().Equals(responseData.EntityTag))
{
sreturn = sEntityIDs[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);
}
private static bool CheckIfUnmodifiedSince(HttpRequest request, ResumableResponseData responseData)
{
string sDate;
DateTime dDate;
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)
sDate = RetrieveHeader(request, HTTP_HEADER_IF_UNMODIFIED_SINCE, String.Empty);
if (sDate.Equals(String.Empty))
// If-Unmodified-Since was not sent, check Unless-Modified-Since...
sDate = RetrieveHeader(request, HTTP_HEADER_UNLESS_MODIFIED_SINCE, String.Empty);
if (sDate.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
dDate = DateTime.Parse(sDate);
// return true if the file was not modified since the indicated date...
breturn = responseData.LastWriteTimeUTC < DateTime.Parse(sDate);
}
catch (Exception)
{
// Converting the indicated date value failed, return false
breturn = false;
}
}
return breturn;
}
private static bool CheckIfNoneMatch(HttpRequest request, ref int statusCode, out string matchedETag, ResumableResponseData responseData)
{
string sRequestHeaderIfNoneMatch;
string[] sEntityIDs;
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)
sRequestHeaderIfNoneMatch = RetrieveHeader(request, HTTP_HEADER_IF_NONE_MATCH, String.Empty);
if (sRequestHeaderIfNoneMatch.Equals(String.Empty))
// Perform the request normally...
breturn = true;
else
{
if (sRequestHeaderIfNoneMatch.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...
sEntityIDs = sRequestHeaderIfNoneMatch.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 = sEntityIDs.GetLowerBound(0); iLoop <= sEntityIDs.GetUpperBound(0); iLoop++)
{
if (sEntityIDs[iLoop].Trim().Equals(responseData.EntityTag))
{
sreturn = sEntityIDs[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;
}
private static bool CheckIfModifiedSince(HttpRequest request, ResumableResponseData responseData)
{
string sDate;
DateTime dDate;
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)
sDate = RetrieveHeader(request, HTTP_HEADER_IF_MODIFIED_SINCE, string.Empty);
if (sDate.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
dDate = DateTime.Parse(sDate);
// return true if the file was modified since or at the indicated date...
breturn = (responseData.LastWriteTimeUTC >= DateTime.Parse(sDate));
}
catch
{
// Converting the indicated date value failed, return false
breturn = false;
}
}
return breturn;
}
private static bool CheckIfMatch(HttpRequest request, ResumableResponseData responseData)
{
string sRequestHeaderIfMatch;
string[] sEntityIDs;
bool breturn = 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)
sRequestHeaderIfMatch = RetrieveHeader(request, HTTP_HEADER_IF_MATCH, "*");
if (sRequestHeaderIfMatch.Equals("*"))
// The server may perform the request as if the
// If-Match header does not exists...
breturn = true;
else
{
// One or more Match IDs where sent by the client software...
sEntityIDs = sRequestHeaderIfMatch.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 = sEntityIDs.GetLowerBound(0); iLoop <= sEntityIDs.GetUpperBound(0); iLoop++)
{
if (sEntityIDs[iLoop].Trim().Equals(responseData.EntityTag))
breturn = true;
}
}
// return the result...
return breturn;
}
public static bool ValidatePartialRequest(HttpRequest request, ResumableResponseData responseData, out string matchedETag, ref int statusCode)
{
const string HTTP_METHOD_GET = "GET";
const string HTTP_METHOD_HEAD = "HEAD";
matchedETag = null;
if (!(responseData.HttpMethod.Equals(HTTP_METHOD_GET) ||
responseData.HttpMethod.Equals(HTTP_METHOD_HEAD)))
{
// Currently, only the GET and HEAD methods
// are supported...
statusCode = 501; // Not implemented
return false;
}
else if (!CheckIfModifiedSince(request, responseData))
{
// The entity is still unmodified...
statusCode = 304; // Not Modified
return false;
}
else if (!CheckIfUnmodifiedSince(request, responseData))
{
// The entity was modified since the requested date...
statusCode = 412; // Precondition failed
return false;
}
else if (!CheckIfMatch(request, responseData))
{
// The entity does not match the request...
statusCode = 412; // Precondition failed
return false;
}
else if (!CheckIfNoneMatch(request, ref statusCode, out matchedETag, responseData))
{
// 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;
}
}
