/// <summary>
/// Resolve ip of host
/// </summary>
/// <param name="host"></param>
/// <returns></returns>
public string Resolve(string host)
{
List <string> ips;
if (_caches.TryGetValue(host.ToLower(), out ips))
{
return(ips[_random.Next(0, ips.Count)]);
}
try
{
var entry = Dns.GetHostEntry(host);
if (entry.AddressList.Length <= 0)
{
return(null);
}
ips = new List <string>();
foreach (var address in entry.AddressList)
{
ips.Add(address.ToString());
}
return(ips[_random.Next(0, ips.Count)]);
}
catch (Exception e)
{
ULogger.Error("DnsCache.Resolve Failed，Reason：" + e.Message);
return(null);
}
}
/// <summary>
/// test if http file could be download resume-from-break
/// </summary>
/// <param name="url"></param>
/// <param name="totalSize"></param>
/// <returns></returns>
static public bool TestSupportRange(string url, out long totalSize)
{
for (;;)
{
HttpWebRequest request = null;
HttpWebResponse response = null;
try
{
request = GetHttpWebRequest(url);
SetupClient(request);
// request.Method = "HEAD";
using (response = (HttpWebResponse)request.GetResponse())
{
totalSize = response.ContentLength;
string data = response.Headers.Get("accept-ranges");
return(!String.IsNullOrEmpty(data) && data == "bytes");
}
}
catch (Exception e)
{
ULogger.Error("TestSupportRange 失败，Url：" + url + "，原因：" + e.Message);
}
finally
{
if (request != null)
{
request.Abort();
}
if (response != null)
{
response.Close();
}
}
}
}
/// <summary>
/// Ensure that file has the specified size
/// </summary>
/// <param name="filePath"></param>
/// <param name="totalSize"></param>
/// <returns></returns>
static public bool EnsureFileSize(string filePath, long totalSize)
{
FileStream fsData = null;
try
{
fsData = new FileStream(filePath, FileMode.OpenOrCreate);
fsData.SetLength(totalSize);
return(true);
}
catch (Exception e)
{
ULogger.Error("FileUtil.EnsureFileSize Failed，Reason：" + e.Message + ", Path：" + filePath);
return(false);
}
finally
{
if (fsData != null)
{
fsData.Close();
}
}
}
/// <summary>
/// download http file within the specified range
/// </summary>
/// <param name="url"></param>
/// <param name="startPos"></param>
/// <param name="endPos"></param>
/// <param name="func"></param>
/// <returns></returns>
static public bool GetFileRange(string url, long startPos, long endPos, Func <byte[], int, bool> func)
{
HttpWebRequest request = null;
HttpWebResponse response = null;
try
{
request = GetHttpWebRequest(url);
SetupClient(request);
request.AddRange("bytes", startPos, endPos);
using (response = (HttpWebResponse)request.GetResponse())
{
// 验证Response中的字节与要求的是否一致
string ranges = response.Headers["Content-Range"];
if (String.IsNullOrEmpty(ranges))
{
return(false);
}
ranges = ranges.ToLower();
if (ranges.IndexOf("bytes") != 0)
{
return(false);
}
ranges = ranges.Replace(" ", "");
ranges = ranges.Replace("\t", "");
ranges = ranges.Remove(0, 5);
int pos = ranges.IndexOf('-');
int pos2 = ranges.IndexOf('/');
if (pos <= 0 || pos2 < pos)
{
return(false);
}
long tmpStart = Int64.Parse(ranges.Substring(0, pos));
long tmpEnd = Int64.Parse(ranges.Substring(pos + 1, pos2 - pos - 1));
if (tmpStart != startPos || tmpEnd != endPos)
{
return(false);
}
var buffer = new byte[10240];
using (var stream = response.GetResponseStream())
{
if (stream == null)
{
return(false);
}
long totalReadCount = 0;
int count;
while ((count = stream.Read(buffer, 0, 10240)) > 0)
{
if (!func(buffer, count))
{
return(false);
}
totalReadCount += count;
if (totalReadCount >= endPos - startPos)
{
break;
}
}
}
return(true);
}
}
catch (Exception e)
{
ULogger.Error("HttpUtil.GetFileRange 失败，原因：" + e.Message + "，Url：" + url);
ULogger.Error(e.StackTrace);
return(false);
}
finally
{
if (request != null)
{
request.Abort();
}
if (response != null)
{
response.Close();
}
}
}
/// <summary>
/// download http file directly
/// </summary>
/// <param name="url"></param>
/// <param name="filePath"></param>
/// <param name="func"></param>
/// <returns></returns>
static public bool GetFileWithProgress(string url, string filePath, Func <long, long, bool> func)
{
FileStream fsData = null;
long totalSize = 0;
long readSize = 0;
HttpWebResponse response = null;
HttpWebRequest request = null;
try
{
fsData = new FileStream(filePath, FileMode.Create);
request = GetHttpWebRequest(url);
SetupClient(request);
var buffer = new Byte[10240];
using (response = (HttpWebResponse)request.GetResponse())
{
var readStream = response.GetResponseStream();
if (readStream == null)
{
throw new Exception("response.GetResponseStream 失败");
}
totalSize = response.ContentLength;
readSize = 0;
if (response.ContentEncoding.ToLower().Contains("gzip"))
{
readStream = new GZipStream(readStream, CompressionMode.Decompress);
}
else if (response.ContentEncoding.ToLower().Contains("deflate"))
{
readStream = new DeflateStream(readStream, CompressionMode.Decompress);
}
using (var reader = new BinaryReader(readStream))
{
int count;
while ((count = reader.Read(buffer, 0, 10240)) > 0)
{
if (func != null)
{
func(readSize, totalSize);
}
fsData.Write(buffer, 0, count);
readSize += count;
}
}
}
return(true);
}
catch (WebException e)
{
ULogger.Error("HttpGetToFile 下载失败，已下载" + readSize + "/" + totalSize + "，原因：" + e.Message + "，URL：" + url + "，filePath：" + filePath);
return(false);
}
finally
{
if (fsData != null)
{
fsData.Close();
fsData.Dispose();
}
if (response != null)
{
response.Close();
}
if (request != null)
{
request.Abort();
}
}
}
