public static CacheEntry Create(NetworkResponse response)
{
var headers = response.Headers;
long server_date = 0;
long server_expires = 0;
long soft_expires = 0;
long max_age = 0;
var has_cache_control = false;
var value = headers.Get("Date");
if (value != null)
{
server_date = ParseDate(value);
}
value = headers.Get("Cache-Control");
if (value != null)
{
has_cache_control = true;
foreach (var token in value.Split(',').Select(x => x.Trim()))
{
if (token == "no-cache" || token == "no-store")
{
return null;
}
else if (token.StartsWith("max-age="))
{
Int64.TryParse(token.Substring(8), out max_age);
}
}
}
value = headers.Get("Expires");
if (value != null)
{
server_expires = ParseDate(value);
}
if (has_cache_control)
{
var now = DateTime.Now.Ticks;
soft_expires = now + max_age * 1000;
}
else if (server_date > 0 && server_expires > + server_date)
{
soft_expires = (server_expires - server_date);
}
return new CacheEntry
{
Data = response.Data,
ETag = headers.Get("ETag"),
Expires = soft_expires,
SoftExpires = soft_expires,
ServerDate = server_date,
Headers = response.Headers,
};
}
public override Response Parse(NetworkResponse response)
{
return(new Response <T>
{
CacheEntry = CacheEntry.Create(response),
Result = ParseJson(response),
});
}
public override Response Parse(NetworkResponse response)
{
return(new Response <string>
{
CacheEntry = CacheEntry.Create(response),
Result = Encoding.UTF8.GetString(response.Data),
});
}
public static CacheEntry Create(NetworkResponse response)
{
long server_date = 0;
long server_expires = 0;
long soft_expires = 0;
long max_age = 0;
var has_cache_control = false;
var value = response.Headers.Get("Date");
if (value != null)
{
server_date = ParseDate(value);
}
value = response.Headers.Get("Cache-Control");
if (value != null)
{
has_cache_control = true;
foreach (var token in value.Split(',').Select(x => x.Trim()))
{
if (token == "no-cache" || token == "no-store")
{
return(null);
}
else if (token.StartsWith("max-age="))
{
Int64.TryParse(token.Substring(8), out max_age);
}
}
}
value = response.Headers.Get("Expires");
if (value != null)
{
server_expires = ParseDate(value);
}
if (has_cache_control)
{
var now = DateTime.Now.Ticks;
soft_expires = now + max_age * 1000;
}
else if (server_date > 0 && server_expires > +server_date)
{
soft_expires = (server_expires - server_date);
}
return(new CacheEntry
{
Data = response.Data,
ETag = response.Headers.Get("ETag"),
Expires = soft_expires,
SoftExpires = soft_expires,
ServerDate = server_date,
Headers = response.Headers,
});
}
private void NetworkConsumer()
{
foreach (var request in _network_queue.GetConsumingEnumerable())
{
request.AddMarker("network-dequeue");
if (request.IsCanceled)
{
request.Finish("network-discard-canceled");
continue;
}
NetworkResponse network_response = null;
try
{
network_response = _network.Execute(request);
request.AddMarker("network-http-complete");
if (network_response.StatusCode == HttpStatusCode.NotModified &&
request.ResponseDelievered)
{
request.Finish("not-modified");
continue;
}
var response = request.Parse(network_response);
request.AddMarker("network-parse-complete");
if (request.ShouldCache && response.CacheEntry != null)
{
_cache[request.CacheKey] = response.CacheEntry;
request.AddMarker("network-cache-written");
}
request.ResponseDelievered = true;
_delivery.PostResponse(request, response);
}
catch (RequestException ex)
{
_delivery.PostException(request, ex);
}
catch (Exception ex)
{
Log.Error(ex, "Unhandled Exception");
var exception = new RequestException("Unhandled exception", ex, network_response);
_delivery.PostException(request, exception);
}
}
}
private T ParseJson(NetworkResponse response)
{
// XXX: can't assume utf8 encoding, need a parseCharset equiv
var json_response = Encoding.UTF8.GetString(response.Data);
try
{
return(_serializer.Deserialize <T>(json_response));
}
catch (Exception ex)
{
throw new ParseException(ex, response);
}
}
public NetworkResponse Execute(Request request)
{
while (true)
{
NetworkResponse response = null;
try
{
var headers = GetCacheHeaders(request.CacheEntry);
response = _client.Execute(request, headers);
if (response.StatusCode == HttpStatusCode.NotModified)
{
return(new NetworkResponse
{
StatusCode = response.StatusCode,
Data = request.CacheEntry.Data,
Headers = response.Headers,
});
}
if (response.StatusCode != HttpStatusCode.OK &&
response.StatusCode != HttpStatusCode.NoContent)
{
throw new IOException();
}
return(response);
}
catch (TimeoutException ex)
{
AttemptRetry(request, ex);
}
catch (IOException ex)
{
if (response == null)
{
throw
new ConnectionException(ex, response);
}
_logger.Error("Unexpected response code {0} for {1}", response.StatusCode, request.Uri);
throw; // XXX logic
}
}
}
public abstract Response Parse(NetworkResponse response);
public RequestException(string message, Exception exception, NetworkResponse response)
: base(message, exception)
{
Response = response;
}
public abstract Response Parse(NetworkResponse response);
public ParseException(Exception exception, NetworkResponse response)
: base("Failed to parse response", exception, response)
{
}
public ConnectionException(Exception exception, NetworkResponse response)
: base("Failed to connect to server", exception, response)
{
}
