public void InitializeRanges(HttpRequestMultipleRangeInfo rangeInfo)
{
IsRangeRequest = rangeInfo.IsRangeApplied;
if (rangeInfo.IsRangeApplied)
{
RangeBegin = rangeInfo.Begin;
RangeEnd = rangeInfo.End;
}
}
/// <summary>
/// Validate
/// </summary>
public bool ValidateHeaderRange(HttpRequest request, HttpRequestMultipleRangeInfo rangeInfo, long contentLength)
{
var validRanges = true;
// Check each found Range request for consistency
for (int index = 0; index <= rangeInfo.Begin.Length; index++)
{
// Check if the requested range values are valid,
// return false if they are not.
//
// Note:
// Do not clean invalid values up by fitting them into
// valid parameters using Math.Min and Math.Max, because
// some download clients (like Go!Zilla) might send invalid
// (e.g. too large) range requests to determine the file limits!
// Begin and end must not exceed the file size
if ((rangeInfo.Begin[index] > (contentLength - 1)) || (rangeInfo.End[index] > (contentLength - 1)))
{
validRanges = false;
}
// Begin and end cannot be < 0
if ((rangeInfo.Begin[index] < 0) || (rangeInfo.End[index] < 0))
{
validRanges = false;
}
// End must be larger or equal to begin value
if (rangeInfo.End[index] < rangeInfo.Begin[index])
{
// The requested Range is invalid...
validRanges = false;
}
}
return(validRanges);
}
/// <summary>
/// Parses user request for range specifed parameters
/// </summary>
public static HttpRequestMultipleRangeInfo ParseHttpRequestHeaderMultipleRange(
HttpRequest request,
long contentLength)
{
//bool validRanges;
string sSource;
int iLoop;
string[] sRanges;
var rangeInfo = new HttpRequestMultipleRangeInfo();
// Parses the Range header from the Request (if there is one)
// returns true, if the Range header was valid, or if there was no
// Range header at all (meaning that the whole
// file was requested)
// returns false, if the Range header asked for unsatisfieable
// ranges
// Retrieve Range Header value from Request (Empty if none is indicated)
sSource = RetrieveHeader(request, HTTP_HEADER_RANGE, String.Empty);
if (string.IsNullOrEmpty(sSource))
{
// No Range was requested, return the entire file range...
rangeInfo.Begin = new long[1];
rangeInfo.End = new long[1];
rangeInfo.Begin[0] = 0;
rangeInfo.End[0] = contentLength - 1;
// no Range request
rangeInfo.IsRangeApplied = false;
}
else
{
// A Range was requested...
// return true for the bRange parameter, telling the caller
// that the Request is indeed a Range request...
rangeInfo.IsRangeApplied = true;
// Remove "bytes=" from the beginning, and split the remaining
// string by comma characters
sRanges = sSource.Replace("bytes=", "").Split(",".ToCharArray());
rangeInfo.Begin = new long[sRanges.GetUpperBound(0) + 1];
rangeInfo.End = new long[sRanges.GetUpperBound(0) + 1];
// Check each found Range request for consistency
for (iLoop = sRanges.GetLowerBound(0); iLoop <= sRanges.GetUpperBound(0); iLoop++)
{
// Split this range request by the dash character,
// sRange(0) contains the requested begin-value,
// sRange(1) contains the requested end-value...
string[] sRange = sRanges[iLoop].Split("-".ToCharArray());
// Determine the end of the requested range
if (sRange[1].Equals(String.Empty))
{
// No end was specified, take the entire range
rangeInfo.End[iLoop] = contentLength - 1;
}
else
{
// An end was specified...
rangeInfo.End[iLoop] = long.Parse(sRange[1]);
}
// Determine the begin of the requested range
if (sRange[0].Equals(String.Empty))
{
// No begin was specified, which means that
// the end value indicated to return the last n
// bytes of the file:
// Calculate the begin
rangeInfo.Begin[iLoop] = contentLength - 1 - rangeInfo.End[iLoop];
// ... to the end of the file...
rangeInfo.End[iLoop] = contentLength - 1;
}
else
{
// A normal begin value was indicated...
rangeInfo.Begin[iLoop] = long.Parse(sRange[0]);
}
}
}
return(rangeInfo);
}
