private static void PutEntry(IPAddress ip, CachedIPHostEntry entry)
{
lock (CachedIPHostEntryDict)
{
if (CachedIPHostEntryDict.ContainsKey(ip))
{
CachedIPHostEntryDict[ip] = entry;
LogHelper.Debug($"End resolve IPHostEntry for {ip}: IsResolved={entry.IsResolved}, HasErrors={entry.HasErrors}, ToolTipText={entry.DisplayText}");
}
else
{
CachedIPHostEntryDict.Add(ip, entry);
LogHelper.Debug($"Start resolve IPHostEntry for {ip}: IsResolved={entry.IsResolved}, HasErrors={entry.HasErrors}, ToolTipText={entry.DisplayText}");
}
}
}
public static async Task <CachedIPHostEntry> ResolveIpAddress(string ip)
{
return(await Task.Run(() =>
{
if (!IsIPValid(ip))
{
return CachedIPHostEntry.EMTPY;
}
IPAddress ipa = null;
try
{
ipa = IPAddress.Parse(ip);
ResolveIP(ipa);
return CachedIPHostEntryDict[ipa];
} catch (Exception e)
{
return CachedIPHostEntry.ERROR_ENTRY(ipa, e);
}
}).ConfigureAwait(false));
}
private static void ResolveIP(IPAddress ip)
{
try
{
if (!CachedIPHostEntryDict.ContainsKey(ip))
{
PutEntry(ip, CachedIPHostEntry.EMTPY); // reserve slot
// http://www.dotnetframework.org/default.aspx/4@0/4@0/DEVDIV_TFS/Dev10/Releases/RTMRel/ndp/fx/src/Net/System/Net/DNS@cs/1305376/DNS@cs
IPHostEntry resolvedEntry = Dns.GetHostEntry(address: ip);
CachedIPHostEntry entry = new CachedIPHostEntry
{
HostEntry = resolvedEntry,
IsResolved = true,
DisplayText = resolvedEntry.HostName
};
PutEntry(ip, entry);
}
}
catch (Exception e)
{
PutEntry(ip, CachedIPHostEntry.ERROR_ENTRY(ip, e));
}
}
