/// <summary>
/// Check If-Match header
/// </summary>
/// <param name="objRequest"></param>
/// <param name="objDownload"></param>
/// <returns></returns>
private static bool CheckIfMatch(HttpRequest objRequest, DownloadFile objFile) //Careful ByVal
{
// Get Request If-Match Header, * is there was none
string sRequestHeaderIfMatch = DownloadHandler.RetrieveHeader(objRequest, HTTP_HEADER_IF_MATCH, "*");
string[] arrEntityIDs;
bool bReturn = false;
if (sRequestHeaderIfMatch.Equals("*"))
{
bReturn = true; // No Match
}
else
{
arrEntityIDs = sRequestHeaderIfMatch.Replace("bytes=", "").Split(",".ToCharArray());
// Iterate entity IDs to see if there's a match to the current file ID
for (int iLoop = arrEntityIDs.GetLowerBound(0); iLoop <= arrEntityIDs.GetUpperBound(0); iLoop++)
{
if (arrEntityIDs[iLoop].Trim().Equals(objFile.EntityTag))
{
bReturn = true;
}
}
}
return(bReturn);
}
/// <summary>
/// Check If-Range header
/// </summary>
/// <param name="objRequest"></param>
/// <param name="objDownload"></param>
/// <returns></returns>
private static bool CheckIfRange(HttpRequest objRequest, DownloadFile objFile) //Careful ByVal
{
// Get Requests If-Range Header value
string sRequestHeaderIfRange = DownloadHandler.RetrieveHeader(objRequest, HTTP_HEADER_IF_RANGE, objFile.EntityTag);
// if (the requested file entity matches the current
// entity uploadId, return True, otherwise return False
return(sRequestHeaderIfRange.Equals(objFile.EntityTag));
}
/// <summary>
/// Check If-Unmodified-Since header
/// </summary>
/// <param name="objRequest"></param>
/// <param name="objDownload"></param>
/// <returns></returns>
private static bool CheckIfUnmodifiedSince(HttpRequest objRequest, DownloadFile objFile)
{
string sSinceDate;
DateTime dtSinceDate;
bool bReturn;
// Retrieve If-Unmodified-Since Header
sSinceDate = DownloadHandler.RetrieveHeader(objRequest, HTTP_HEADER_IF_UNMODIFIED_SINCE, String.Empty);
if (String.IsNullOrEmpty(sSinceDate))
{
sSinceDate = DownloadHandler.RetrieveHeader(objRequest, HTTP_HEADER_UNLESS_MODIFIED_SINCE, String.Empty);
}
if (String.IsNullOrEmpty(sSinceDate))
{
bReturn = true;
}
else
{
bool bTry = DateTime.TryParse(sSinceDate, out dtSinceDate); //dtSinceDate is a local date without millisecs
DateTime dtSinceDateUTC = dtSinceDate.ToUniversalTime();
DateTime dtLastWriteTimeUTC = new DateTime(
objFile.LastWriteTimeUTC.Year,
objFile.LastWriteTimeUTC.Month,
objFile.LastWriteTimeUTC.Day,
objFile.LastWriteTimeUTC.Hour,
objFile.LastWriteTimeUTC.Minute,
objFile.LastWriteTimeUTC.Second,
DateTimeKind.Utc);
if (bTry)
{
bReturn = (dtLastWriteTimeUTC <= dtSinceDateUTC); // True if the file was not modified
}
else
{
bReturn = false;
}
}
return(bReturn);
}
/// <summary>
/// Check If-None-Match header
/// </summary>
/// <param name="objRequest"></param>
/// <param name="objResponse"></param>
/// <param name="objDownload"></param>
/// <returns></returns>
private static bool CheckIfNoneMatch(HttpRequest objRequest, HttpResponse objResponse, DownloadFile objFile) //Careful ByVal
{
string sRequestHeaderIfNoneMatch;
string[] arrEntityIDs;
bool bReturn = true;
string sReturn = "";
// Get Request If-None-Match Header value
sRequestHeaderIfNoneMatch = DownloadHandler.RetrieveHeader(objRequest, HTTP_HEADER_IF_NONE_MATCH, String.Empty);
if (String.IsNullOrEmpty(sRequestHeaderIfNoneMatch))
{
bReturn = true; // Perform request normally
}
else if (sRequestHeaderIfNoneMatch.Equals("*"))
{
objResponse.StatusCode = 412; // logically invalid request
bReturn = false;
}
else
{
arrEntityIDs = sRequestHeaderIfNoneMatch.Replace("bytes=", "").Split(",".ToCharArray());
// EntIDs were sent - Look for a match to the current one
for (int iLoop = arrEntityIDs.GetLowerBound(0); iLoop <= arrEntityIDs.GetUpperBound(0); iLoop++)
{
if (arrEntityIDs[iLoop].Trim().Equals(objFile.EntityTag))
{
sReturn = arrEntityIDs[iLoop];
// One of the requested entities matches the current file's tag,
objResponse.AppendHeader(HTTP_HEADER_ENTITY_TAG, sReturn);
objResponse.StatusCode = 304; // Not Modified
bReturn = true;
}
}
}
return(bReturn);
}
/// <summary>
/// Check If-Modified-Since header
/// </summary>
/// <param name="objRequest"></param>
/// <param name="objDownload"></param>
/// <returns></returns>
private static bool CheckIfModifiedSince(HttpRequest objRequest, DownloadFile objFile) //Careful ByVal
{
string sSinceDate;
DateTime dtSinceDate;
bool bReturn;
// Retrieve If-Modified-Since Header
sSinceDate = DownloadHandler.RetrieveHeader(objRequest, HTTP_HEADER_IF_MODIFIED_SINCE, String.Empty);
if (String.IsNullOrEmpty(sSinceDate))
{
bReturn = true; // if (no date was sent - assume we need to re-download the whole file
}
else
{
bool bTry = DateTime.TryParse(sSinceDate, out dtSinceDate); //dtSinceDate is a local date without millisecs
DateTime dtSinceDateUTC = dtSinceDate.ToUniversalTime();
DateTime dtLastWriteTimeUTC = new DateTime(
objFile.LastWriteTimeUTC.Year,
objFile.LastWriteTimeUTC.Month,
objFile.LastWriteTimeUTC.Day,
objFile.LastWriteTimeUTC.Hour,
objFile.LastWriteTimeUTC.Minute,
objFile.LastWriteTimeUTC.Second,
DateTimeKind.Utc);
if (bTry)
{
bReturn = (dtLastWriteTimeUTC > dtSinceDateUTC); // True if the file was actually modified
}
else
{
bReturn = false;
}
}
return(bReturn);
}
/// <summary>
///
/// </summary>
/// <param name="objRequest"></param>
/// <param name="lBegin"></param>
/// <param name="lEnd"></param>
/// <param name="lMax"></param>
/// <param name="bRangeRequest"></param>
/// <returns></returns>
private static bool ParseRequestHeaderRange(HttpRequest objRequest, long lMax, ref long[] lBegin, ref long[] lEnd, ref bool bRangeRequest) //Some ByVal some ByRef
{
bool bValidRangesRet;
string sSource;
//int iLoop;
string[] arrRanges;
// Retrieve Range Header from Request
sSource = DownloadHandler.RetrieveHeader(objRequest, HTTP_HEADER_RANGE, String.Empty);
if (String.IsNullOrEmpty(sSource)) // No Range was requested
{
Array.Resize <long>(ref lBegin, 1);
Array.Resize <long>(ref lEnd, 1);
lBegin[0] = 0;
lEnd[0] = lMax - 1;
bValidRangesRet = true;
bRangeRequest = false;
}
else
{
bValidRangesRet = true;
bRangeRequest = true;
// Remove "bytes=" string, and split the rest
arrRanges = sSource.Replace("bytes=", "").Split(",".ToCharArray());
Array.Resize <long>(ref lBegin, arrRanges.GetUpperBound(0) + 1);
Array.Resize <long>(ref lEnd, arrRanges.GetUpperBound(0) + 1);
// Check each Range request
for (int iLoop = arrRanges.GetLowerBound(0); iLoop <= arrRanges.GetUpperBound(0); iLoop++)
{
// arrRange(0) is the begin value - arrRange(1) is the end value.
string[] arrRange = arrRanges[iLoop].Split("-".ToCharArray());
if (String.IsNullOrEmpty(arrRange[1])) // No end was specified
{
lEnd[iLoop] = lMax - 1;
}
else
{
lEnd[iLoop] = long.Parse(arrRange[1], CultureInfo.InvariantCulture);
}
if (String.IsNullOrEmpty(arrRange[0]))
{
// Calculate the beginning and end.
lBegin[iLoop] = lMax - 1 - lEnd[iLoop];
lEnd[iLoop] = lMax - 1;
}
else
{
lBegin[iLoop] = long.Parse(arrRange[0], CultureInfo.InvariantCulture);
}
// Begin and end must not exceed the total file size
if ((lBegin[iLoop] > (lMax - 1)) || (lEnd[iLoop] > (lMax - 1)))
{
bValidRangesRet = false;
}
// Begin and end cannot be < 0
if ((lBegin[iLoop] < 0) || (lEnd[iLoop] < 0))
{
bValidRangesRet = false;
}
// End must be larger or equal to begin value
if (lEnd[iLoop] < lBegin[iLoop])
{
bValidRangesRet = false;
}
}
}
return(bValidRangesRet);
}