public static CacheMetaData AddToCache(HttpWebResponse resp, string file)
{
string md5 = resp.Headers[HttpResponseHeader.ETag].Split(':')[0].Substring(1);
CacheMetaData meta = new CacheMetaData(resp.ContentLength, md5.ToByteArray());
meta.Save(file);
return(meta);
}
public void DownloadFile(string url, string path)
{
Directory.CreateDirectory(Path.GetDirectoryName(path));
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
using (HttpWebResponse resp = (HttpWebResponse)request.GetResponse())
using (Stream stream = resp.GetResponseStream())
using (Stream fs = new FileStream(path, FileMode.Create, FileAccess.Write))
{
CacheMetaData.AddToCache(resp, path);
CopyToStream(stream, fs, resp.ContentLength);
}
}
public Stream OpenFile(string name, string url, bool isData)
{
if (!Enabled)
{
return(null);
}
if (isData && !CacheData)
{
return(null);
}
string file = cachePath + "/" + name;
Log.Write("CDNCache: Opening file {0}", file);
FileInfo fi = new FileInfo(file);
if (!fi.Exists)
{
downloader.DownloadFile(url, file);
}
if (Validate)
{
CacheMetaData meta = CacheMetaData.Load(file) ?? downloader.GetMetaData(url, file);
if (meta == null)
{
throw new Exception(string.Format("unable to validate file {0}", file));
}
bool sizeOk, md5Ok;
using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
sizeOk = fs.Length == meta.Size;
md5Ok = md5.ComputeHash(fs).EqualsTo(meta.MD5);
}
if (!sizeOk || !md5Ok)
{
downloader.DownloadFile(url, file);
}
}
return(new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.ReadWrite));
}
public CacheMetaData GetMetaData(string url, string file)
{
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "HEAD";
using (HttpWebResponse resp = (HttpWebResponse)request.GetResponse())
{
return(CacheMetaData.AddToCache(resp, file));
}
}
catch
{
return(null);
}
}