internal static NameValueHeaderValue Find(ObjectCollection <NameValueHeaderValue> values, string name)
{
Debug.Assert((name != null) && (name.Length > 0));
if ((values == null) || (values.Count == 0))
{
return(null);
}
foreach (var value in values)
{
if (string.Equals(value.Name, name, StringComparison.OrdinalIgnoreCase))
{
return(value);
}
}
return(null);
}
private static void AppendValues(StringBuilder sb, ObjectCollection <string> values)
{
bool first = true;
foreach (string value in values)
{
if (first)
{
first = false;
}
else
{
sb.Append(", ");
}
sb.Append(value);
}
}
internal static void ToString(ObjectCollection <NameValueHeaderValue> values, char separator, bool leadingSeparator,
StringBuilder destination)
{
Debug.Assert(destination != null);
if ((values == null) || (values.Count == 0))
{
return;
}
foreach (var value in values)
{
if (leadingSeparator || (destination.Length > 0))
{
destination.Append(separator);
destination.Append(' ');
}
value.AddToStringBuilder(destination);
}
}
// Returns the length of a name/value list, separated by 'delimiter'. E.g. "a=b, c=d, e=f" adds 3
// name/value pairs to 'nameValueCollection' if 'delimiter' equals ','.
internal static int GetNameValueListLength(string input, int startIndex, char delimiter,
ObjectCollection <NameValueHeaderValue> nameValueCollection)
{
Debug.Assert(nameValueCollection != null);
Debug.Assert(startIndex >= 0);
if ((string.IsNullOrEmpty(input)) || (startIndex >= input.Length))
{
return(0);
}
int current = startIndex + HttpRuleParser.GetWhitespaceLength(input, startIndex);
while (true)
{
NameValueHeaderValue parameter = null;
int nameValueLength = NameValueHeaderValue.GetNameValueLength(input, current,
s_defaultNameValueCreator, out parameter);
if (nameValueLength == 0)
{
return(0);
}
nameValueCollection.Add(parameter);
current = current + nameValueLength;
current = current + HttpRuleParser.GetWhitespaceLength(input, current);
if ((current == input.Length) || (input[current] != delimiter))
{
// We're done and we have at least one valid name/value pair.
return(current - startIndex);
}
// input[current] is 'delimiter'. Skip the delimiter and whitespace and try to parse again.
current++; // skip delimiter.
current = current + HttpRuleParser.GetWhitespaceLength(input, current);
}
}
internal static void SetQuality(ObjectCollection <NameValueHeaderValue> parameters, double?value)
{
Debug.Assert(parameters != null);
NameValueHeaderValue qualityParameter = NameValueHeaderValue.Find(parameters, qualityName);
if (value.HasValue)
{
// Note that even if we check the value here, we can't prevent a user from adding an invalid quality
// value using Parameters.Add(). Even if we would prevent the user from adding an invalid value
// using Parameters.Add() he could always add invalid values using HttpHeaders.AddWithoutValidation().
// So this check is really for convenience to show users that they're trying to add an invalid
// value.
if ((value < 0) || (value > 1))
{
throw new ArgumentOutOfRangeException(nameof(value));
}
string qualityString = ((double)value).ToString("0.0##", NumberFormatInfo.InvariantInfo);
if (qualityParameter != null)
{
qualityParameter.Value = qualityString;
}
else
{
parameters.Add(new NameValueHeaderValue(qualityName, qualityString));
}
}
else
{
// Remove quality parameter
if (qualityParameter != null)
{
parameters.Remove(qualityParameter);
}
}
}
internal static double?GetQuality(ObjectCollection <NameValueHeaderValue> parameters)
{
Debug.Assert(parameters != null);
NameValueHeaderValue qualityParameter = NameValueHeaderValue.Find(parameters, qualityName);
if (qualityParameter != null)
{
// Note that the RFC requires decimal '.' regardless of the culture. I.e. using ',' as decimal
// separator is considered invalid (even if the current culture would allow it).
double qualityValue = 0;
if (double.TryParse(qualityParameter.Value, NumberStyles.AllowDecimalPoint,
NumberFormatInfo.InvariantInfo, out qualityValue))
{
return(qualityValue);
}
// If the stored value is an invalid quality value, just return null and log a warning.
if (NetEventSource.IsEnabled)
{
NetEventSource.Error(null, SR.Format(SR.net_http_log_headers_invalid_quality, qualityParameter.Value));
}
}
return(null);
}
private static bool TrySetOptionalTokenList(NameValueHeaderValue nameValue, ref bool boolField,
ref ObjectCollection <string> destination)
{
Debug.Assert(nameValue != null);
if (nameValue.Value == null)
{
boolField = true;
return(true);
}
// We need the string to be at least 3 chars long: 2x quotes and at least 1 character. Also make sure we
// have a quoted string. Note that NameValueHeaderValue will never have leading/trailing whitespace.
string valueString = nameValue.Value;
if ((valueString.Length < 3) || (valueString[0] != '\"') || (valueString[valueString.Length - 1] != '\"'))
{
return(false);
}
// We have a quoted string. Now verify that the string contains a list of valid tokens separated by ','.
int current = 1; // skip the initial '"' character.
int maxLength = valueString.Length - 1; // -1 because we don't want to parse the final '"'.
bool separatorFound = false;
int originalValueCount = destination == null ? 0 : destination.Count;
while (current < maxLength)
{
current = HeaderUtilities.GetNextNonEmptyOrWhitespaceIndex(valueString, current, true,
out separatorFound);
if (current == maxLength)
{
break;
}
int tokenLength = HttpRuleParser.GetTokenLength(valueString, current);
if (tokenLength == 0)
{
// We already skipped whitespace and separators. If we don't have a token it must be an invalid
// character.
return(false);
}
if (destination == null)
{
destination = new ObjectCollection <string>(s_checkIsValidToken);
}
destination.Add(valueString.Substring(current, tokenLength));
current = current + tokenLength;
}
// After parsing a valid token list, we expect to have at least one value
if ((destination != null) && (destination.Count > originalValueCount))
{
boolField = true;
return(true);
}
return(false);
}
internal static bool AreEqualCollections <T>(ObjectCollection <T> x, ObjectCollection <T> y, IEqualityComparer <T> comparer) where T : class
{
if (x == null)
{
return((y == null) || (y.Count == 0));
}
if (y == null)
{
return(x.Count == 0);
}
if (x.Count != y.Count)
{
return(false);
}
if (x.Count == 0)
{
return(true);
}
// We have two unordered lists. So comparison is an O(n*m) operation which is expensive. Usually
// headers have 1-2 parameters (if any), so this comparison shouldn't be too expensive.
bool[] alreadyFound = new bool[x.Count];
int i = 0;
foreach (var xItem in x)
{
Debug.Assert(xItem != null);
i = 0;
bool found = false;
foreach (var yItem in y)
{
if (!alreadyFound[i])
{
if (((comparer == null) && xItem.Equals(yItem)) ||
((comparer != null) && comparer.Equals(xItem, yItem)))
{
alreadyFound[i] = true;
found = true;
break;
}
}
i++;
}
if (!found)
{
return(false);
}
}
// Since we never re-use a "found" value in 'y', we expect 'alreadyFound' to have all fields set to 'true'.
// Otherwise the two collections can't be equal and we should not get here.
Debug.Assert(Contract.ForAll(alreadyFound, value => { return(value); }),
"Expected all values in 'alreadyFound' to be true since collections are considered equal.");
return(true);
}
internal static bool AreEqualCollections <T>(ObjectCollection <T> x, ObjectCollection <T> y) where T : class
{
return(AreEqualCollections(x, y, null));
}
