/// <summary>
/// Download the requested bytes
/// </summary>
private HttpWebRequest CreateHttpWebRequest(int[,] byteRanges)
{
HttpWebRequest request;
// Create the request object
request = (HttpWebRequest)WpfWebRequestHelper.CreateRequest(_requestedUri);
request.ProtocolVersion = HttpVersion.Version11;
request.Method = "GET";
// Set the Proxy to Empty one; If we don't set this to empty one, it will try to find one for us
// and ends up triggering JScript in another assembly. This will throw PolicyException since the JScript
// dll doesn't have execution right. This is a bug in CLR; supposed to be fixed later
// Future work: Need to keep consistent HTTP stack with the WININET one (e.g. authentication, proxy, cookies)
// IWebProxy emptyProxy = GlobalProxySelection.GetEmptyWebProxy();
// request.Proxy = emptyProxy;
// Local assert to allow Proxy get/set under partial trust
new WebPermission(PermissionState.Unrestricted).Assert(); // Blessed
try
{
request.Proxy = _proxy;
}
finally
{
WebPermission.RevertAssert();
}
request.Credentials = _credentials;
request.CachePolicy = _cachePolicy;
// Add byte ranges (to header)
for (int i = 0; i < byteRanges.GetLength(0); ++i)
{
request.AddRange(byteRanges[i, Offset_Index],
byteRanges[i, Offset_Index] + byteRanges[i, Length_Index] - 1);
}
return(request);
}
private HttpWebRequest CreateHttpWebRequest(int[,] byteRanges)
{
HttpWebRequest request;
// Create the request object
request = (HttpWebRequest)WpfWebRequestHelper.CreateRequest(_requestedUri);
request.ProtocolVersion = HttpVersion.Version11;
request.Method = "GET";
// Set the Proxy to Empty one; If we don't set this to empty one, it will try to find one for us
// and ends up triggering JScript in another assembly. This will throw PolicyException since the JScript
// dll doesn't have execution right. This is
// Local assert to allow Proxy get/set under partial trust
new WebPermission(PermissionState.Unrestricted).Assert(); // Blessed
try
{
request.Proxy = _proxy;
}
finally
{
WebPermission.RevertAssert();
}
request.Credentials = _credentials;
request.CachePolicy = _cachePolicy;
// Add byte ranges (to header)
for (int i = 0; i < byteRanges.GetLength(0); ++i)
{
request.AddRange(byteRanges[i, Offset_Index],
byteRanges[i, Offset_Index] + byteRanges[i, Length_Index] - 1);
}
return(request);
}
///
/// Begin a download
///
internal static void BeginDownload(
BitmapDecoder decoder,
Uri uri,
RequestCachePolicy uriCachePolicy,
Stream stream
)
{
lock (_syncLock)
{
if (!_thread.IsAlive)
{
_thread.IsBackground = true;
_thread.Start();
}
}
QueueEntry entry;
// If there is already a download for this uri, just add the decoder to the list
if (uri != null)
{
lock (_syncLock)
{
if (_uriTable[uri] != null)
{
entry = (QueueEntry)_uriTable[uri];
entry.decoders.Add(new WeakReference(decoder));
return;
}
}
}
entry = new QueueEntry();
entry.decoders = new List <WeakReference>();
lock (_syncLock)
{
entry.decoders.Add(new WeakReference(decoder));
}
entry.inputUri = uri;
entry.inputStream = stream;
string cacheFolder = MS.Win32.WinInet.InternetCacheFolder.LocalPath;
bool passed = false;
new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Assert(); // BlessedAssert
try
{
// Get the file path
StringBuilder tmpFileName = new StringBuilder(NativeMethods.MAX_PATH);
MS.Win32.UnsafeNativeMethods.GetTempFileName(cacheFolder, "WPF", 0, tmpFileName);
try
{
string pathToUse = tmpFileName.ToString();
SafeFileHandle fileHandle = MS.Win32.UnsafeNativeMethods.CreateFile(
pathToUse,
NativeMethods.GENERIC_READ | NativeMethods.GENERIC_WRITE, /* dwDesiredAccess */
0, /* dwShare */
null, /* lpSecurityAttributes */
NativeMethods.CREATE_ALWAYS, /* dwCreationDisposition */
NativeMethods.FILE_ATTRIBUTE_TEMPORARY |
NativeMethods.FILE_FLAG_DELETE_ON_CLOSE, /* dwFlagsAndAttributes */
IntPtr.Zero /* hTemplateFile */
);
if (fileHandle.IsInvalid)
{
throw new Win32Exception();
}
entry.outputStream = new FileStream(fileHandle, FileAccess.ReadWrite);
entry.streamPath = pathToUse;
passed = true;
}
catch (Exception e)
{
if (CriticalExceptions.IsCriticalException(e))
{
throw;
}
}
}
finally
{
SecurityPermission.RevertAssert();
}
if (!passed)
{
throw new IOException(SR.Get(SRID.Image_CannotCreateTempFile));
}
entry.readBuffer = new byte[READ_SIZE];
entry.contentLength = -1;
entry.contentType = string.Empty;
entry.lastPercent = 0;
// Add the entry to the table if we know the uri
if (uri != null)
{
lock (_syncLock)
{
_uriTable[uri] = entry;
}
}
if (stream == null)
{
bool fElevate = false;
if (uri.Scheme == Uri.UriSchemeHttp || uri.Scheme == Uri.UriSchemeHttps)
{
SecurityHelper.BlockCrossDomainForHttpsApps(uri);
// In this case we first check to see if the consumer has media permissions for
// safe media (Site of Origin + Cross domain), if it
// does we assert and run the code that requires the assert
if (SecurityHelper.CallerHasMediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.SafeImage))
{
fElevate = true;
}
}
// This is the case where we are accessing an http image from an http site and we have media permission
if (fElevate)
{
(new WebPermission(NetworkAccess.Connect, BindUriHelper.UriToString(uri))).Assert(); // BlessedAssert
}
try
{
entry.webRequest = WpfWebRequestHelper.CreateRequest(uri);
if (uriCachePolicy != null)
{
entry.webRequest.CachePolicy = uriCachePolicy;
}
}
finally
{
if (fElevate)
{
WebPermission.RevertAssert();
}
}
entry.webRequest.BeginGetResponse(_responseCallback, entry);
}
else
{
_workQueue.Enqueue(entry);
// Signal
_waitEvent.Set();
}
}