internal IEnumerable <KeyValuePair <string, string> > GetHeaderStrings()
{
if (headerStore == null)
{
yield break;
}
foreach (var header in headerStore)
{
HeaderStoreItemInfo info = header.Value;
string[] values = GetValuesAsStrings(info);
string stringValue = string.Empty; // returned if values.Length == 0
if (values.Length == 1)
{
stringValue = values[0];
}
else
{
// Note that if we get multiple values for a header that doesn't support multiple values, we'll
// just separate the values using a comma (default separator).
string separator = HttpHeaderParser.DefaultSeparator;
if ((info.Parser != null) && (info.Parser.SupportsMultipleValues))
{
separator = info.Parser.Separator;
}
stringValue = string.Join(separator, values);
}
yield return(new KeyValuePair <string, string>(header.Key, stringValue));
}
}
private static void AddValueToStoreValue <T>(HeaderStoreItemInfo info, object value,
ref object currentStoreValue) where T : class
{
// If there is no value set yet, then add current item as value (we don't create a list
// if not required). If 'info.Value' is already assigned then make sure 'info.Value' is a
// List<T> and append 'item' to the list.
if (currentStoreValue == null)
{
currentStoreValue = value;
}
else
{
List <T> storeValues = currentStoreValue as List <T>;
if (storeValues == null)
{
storeValues = new List <T>(2);
Contract.Assert(value is T);
storeValues.Add(currentStoreValue as T);
currentStoreValue = storeValues;
}
Contract.Assert(value is T);
storeValues.Add(value as T);
}
}
private HeaderStoreItemInfo GetOrCreateHeaderInfo(string name, bool parseRawValues)
{
Contract.Requires((name != null) && (name.Length > 0));
Contract.Requires(HttpRuleParser.GetTokenLength(name, 0) == name.Length);
Contract.Ensures(Contract.Result <HeaderStoreItemInfo>() != null);
HeaderStoreItemInfo result = null;
bool found = false;
if (parseRawValues)
{
found = TryGetAndParseHeaderInfo(name, out result);
}
else
{
found = TryGetHeaderInfo(name, out result);
}
if (!found)
{
result = CreateAndAddHeaderToStore(name);
}
return(result);
}
private void AddHeaderToStore(string name, HeaderStoreItemInfo info)
{
if (headerStore == null)
{
headerStore = new Dictionary <string, HeaderStoreItemInfo>(
HeaderUtilities.CaseInsensitiveStringComparer);
}
headerStore.Add(name, info);
}
private bool TryGetAndParseHeaderInfo(string name, out HeaderStoreItemInfo info)
{
if (TryGetHeaderInfo(name, out info))
{
return(ParseRawHeaderValues(name, info, true));
}
return(false);
}
private HeaderStoreItemInfo CreateAndAddHeaderToStore(string name)
{
// If we don't have the header in the store yet, add it now.
HeaderStoreItemInfo result = new HeaderStoreItemInfo(GetParser(name));
AddHeaderToStore(name, result);
return(result);
}
internal bool ContainsParsedValue(string name, object value)
{
Contract.Requires((name != null) && (name.Length > 0));
Contract.Requires(HttpRuleParser.GetTokenLength(name, 0) == name.Length);
Contract.Requires(value != null);
if (headerStore == null)
{
return(false);
}
// If we have a value for this header, then verify if we have a single value. If so, compare that
// value with 'item'. If we have a list of values, then compare each item in the list with 'item'.
HeaderStoreItemInfo info = null;
if (TryGetAndParseHeaderInfo(name, out info))
{
Contract.Assert(info.Parser != null, "Can't add parsed value if there is no parser available.");
Contract.Assert(info.Parser.SupportsMultipleValues,
"This method should not be used for single-value headers. Use equality comparer instead.");
// If there is no entry, just return.
if (info.ParsedValue == null)
{
return(false);
}
List <object> parsedValues = info.ParsedValue as List <object>;
IEqualityComparer comparer = info.Parser.Comparer;
if (parsedValues == null)
{
Contract.Assert(info.ParsedValue.GetType() == value.GetType(),
"Stored value does not have the same type as 'value'.");
return(AreEqual(value, info.ParsedValue, comparer));
}
else
{
foreach (object item in parsedValues)
{
Contract.Assert(item.GetType() == value.GetType(),
"One of the stored values does not have the same type as 'value'.");
if (AreEqual(value, item, comparer))
{
return(true);
}
}
return(false);
}
}
return(false);
}
private bool TryGetHeaderInfo(string name, out HeaderStoreItemInfo info)
{
if (headerStore == null)
{
info = null;
return(false);
}
return(headerStore.TryGetValue(name, out info));
}
private void PrepareHeaderInfoForAdd(string name, out HeaderStoreItemInfo info, out bool addToStore)
{
info = null;
addToStore = false;
if (!TryGetAndParseHeaderInfo(name, out info))
{
info = new HeaderStoreItemInfo(GetParser(name));
addToStore = true;
}
}
private static int GetValueCount(HeaderStoreItemInfo info)
{
Contract.Requires(info != null);
int valueCount = 0;
UpdateValueCount <string>(info.RawValue, ref valueCount);
UpdateValueCount <string>(info.InvalidValue, ref valueCount);
UpdateValueCount <object>(info.ParsedValue, ref valueCount);
return(valueCount);
}
internal void AddHeaders(HttpHeaders sourceHeaders)
{
Contract.Requires(sourceHeaders != null);
Contract.Assert(this.parserStore == sourceHeaders.parserStore,
"Can only copy headers from an instance with the same header parsers.");
if (sourceHeaders.headerStore == null)
{
return;
}
List <string> invalidHeaders = null;
foreach (var header in sourceHeaders.headerStore)
{
// Only add header values if they're not already set on the message. Note that we don't merge
// collections: If both the default headers and the message have set some values for a certain
// header, then we don't try to merge the values.
if ((headerStore == null) || (!headerStore.ContainsKey(header.Key)))
{
HeaderStoreItemInfo sourceInfo = header.Value;
// If DefaultRequestHeaders values are copied to multiple messages, it is useful to parse these
// default header values only once. This is what we're doing here: By parsing raw headers in
// 'sourceHeaders' before copying values to our header store.
if (!sourceHeaders.ParseRawHeaderValues(header.Key, sourceInfo, false))
{
// If after trying to parse source header values no value is left (i.e. all values contain
// invalid newline chars), mark this header as 'to-be-deleted' and skip to the next header.
if (invalidHeaders == null)
{
invalidHeaders = new List <string>();
}
invalidHeaders.Add(header.Key);
}
else
{
AddHeaderInfo(header.Key, sourceInfo);
}
}
}
if (invalidHeaders != null)
{
Contract.Assert(sourceHeaders.headerStore != null);
foreach (string invalidHeader in invalidHeaders)
{
sourceHeaders.headerStore.Remove(invalidHeader);
}
}
}
// Since most of the time we just have 1 value, we don't create a List<object> for one value, but we change
// the return type to 'object'. The caller has to deal with the return type (object vs. List<object>). This
// is to optimize the most common scenario where a header has only one value.
internal object GetParsedValues(string name)
{
Contract.Requires((name != null) && (name.Length > 0));
Contract.Requires(HttpRuleParser.GetTokenLength(name, 0) == name.Length);
HeaderStoreItemInfo info = null;
if (!TryGetAndParseHeaderInfo(name, out info))
{
return(null);
}
return(info.ParsedValue);
}
private static void CloneAndAddValue(HeaderStoreItemInfo destinationInfo, object source)
{
// We only have one value. Clone it and assign it to the store.
ICloneable cloneableValue = source as ICloneable;
if (cloneableValue != null)
{
AddValue(destinationInfo, cloneableValue.Clone(), StoreLocation.Parsed);
}
else
{
// If it doesn't implement ICloneable, it's a value type or an immutable type like String/Uri.
AddValue(destinationInfo, source, StoreLocation.Parsed);
}
}
internal void AddParsedValue(string name, object value)
{
Contract.Requires((name != null) && (name.Length > 0));
Contract.Requires(HttpRuleParser.GetTokenLength(name, 0) == name.Length);
Contract.Requires(value != null);
HeaderStoreItemInfo info = GetOrCreateHeaderInfo(name, true);
Contract.Assert(info.Parser != null, "Can't add parsed value if there is no parser available.");
// If the current header has only one value, we can't add another value. The strongly typed property
// must not call AddParsedValue(), but SetParsedValue(). E.g. for headers like 'Date', 'Host'.
Contract.Assert(info.CanAddValue, "Header '" + name + "' doesn't support multiple values");
AddValue(info, value, StoreLocation.Parsed);
}
public bool Contains(string name)
{
CheckHeaderName(name);
if (headerStore == null)
{
return(false);
}
// We can't just call headerStore.ContainsKey() since after parsing the value the header may not exist
// anymore (if the value contains invalid newline chars, we remove the header). So try to parse the
// header value.
HeaderStoreItemInfo info = null;
return(TryGetAndParseHeaderInfo(name, out info));
}
public void AddWithoutValidation(string name, string value)
{
CheckHeaderName(name);
if (value == null)
{
// We allow empty header values. (e.g. "My-Header: "). If the user adds multiple null/empty
// values, we'll just add them to the collection. This will result in delimiter-only values:
// E.g. adding two null-strings (or empty, or whitespace-only) results in "My-Header: ,".
value = string.Empty;
}
HeaderStoreItemInfo info = GetOrCreateHeaderInfo(name, false);
AddValue(info, value, StoreLocation.Raw);
}
public IEnumerator <KeyValuePair <string, IEnumerable <string> > > GetEnumerator()
{
if (headerStore == null)
{
yield break;
}
List <string> invalidHeaders = null;
foreach (var header in headerStore)
{
HeaderStoreItemInfo info = header.Value;
// Make sure we parse all raw values before returning the result. Note that this has to be
// done before we calculate the array length (next line): A raw value may contain a list of
// values.
if (!ParseRawHeaderValues(header.Key, info, false))
{
// We have an invalid header value (contains invalid newline chars). Mark it as "to-be-deleted"
// and skip this header.
if (invalidHeaders == null)
{
invalidHeaders = new List <string>();
}
invalidHeaders.Add(header.Key);
}
else
{
string[] values = GetValuesAsStrings(info);
yield return(new KeyValuePair <string, IEnumerable <string> >(header.Key, values));
}
}
// While we were enumerating headers, we also parsed header values. If during parsing it turned out that
// the header value was invalid (contains invalid newline chars), remove the header from the store after
// completing the enumeration.
if (invalidHeaders != null)
{
Contract.Assert(headerStore != null);
foreach (string invalidHeader in invalidHeaders)
{
headerStore.Remove(invalidHeader);
}
}
}
internal void SetParsedValue(string name, object value)
{
Contract.Requires((name != null) && (name.Length > 0));
Contract.Requires(HttpRuleParser.GetTokenLength(name, 0) == name.Length);
Contract.Requires(value != null);
// This method will first clear all values. This is used e.g. when setting the 'Date' or 'Host' header.
// I.e. headers not supporting collections.
HeaderStoreItemInfo info = GetOrCreateHeaderInfo(name, true);
Contract.Assert(info.Parser != null, "Can't add parsed value if there is no parser available.");
info.InvalidValue = null;
info.ParsedValue = null;
info.RawValue = null;
AddValue(info, value, StoreLocation.Parsed);
}
private void AddHeaderInfo(string headerName, HeaderStoreItemInfo sourceInfo)
{
HeaderStoreItemInfo destinationInfo = CreateAndAddHeaderToStore(headerName);
Contract.Assert(sourceInfo.Parser == destinationInfo.Parser,
"Expected same parser on both source and destination header store for header '" + headerName +
"'.");
// We have custom header values. The parsed values are strings.
if (destinationInfo.Parser == null)
{
Contract.Assert((sourceInfo.RawValue == null) && (sourceInfo.InvalidValue == null),
"No raw or invalid values expected for custom headers.");
// Custom header values are always stored as string or list of strings.
destinationInfo.ParsedValue = CloneStringHeaderInfoValues(sourceInfo.ParsedValue);
}
else
{
// We have a parser, so we have to copy invalid values and clone parsed values.
// Invalid values are always strings. Strings are immutable. So we only have to clone the
// collection (if there is one).
destinationInfo.InvalidValue = CloneStringHeaderInfoValues(sourceInfo.InvalidValue);
// Now clone and add parsed values (if any).
if (sourceInfo.ParsedValue != null)
{
List <object> sourceValues = sourceInfo.ParsedValue as List <object>;
if (sourceValues == null)
{
CloneAndAddValue(destinationInfo, sourceInfo.ParsedValue);
}
else
{
foreach (object item in sourceValues)
{
CloneAndAddValue(destinationInfo, item);
}
}
}
}
}
private static void AddValue(HeaderStoreItemInfo info, object value, StoreLocation location)
{
// Since we have the same pattern for all three store locations (raw, invalid, parsed), we use
// this helper method to deal with adding values:
// - if 'null' just set the store property to 'value'
// - if 'List<T>' append 'value' to the end of the list
// - if 'T', i.e. we have already a value stored (but no list), create a list, add the stored value
// to the list and append 'value' at the end of the newly created list.
Contract.Assert((info.Parser != null) || ((info.Parser == null) && (value.GetType() == typeof(string))),
"If no parser is defined, then the value must be string.");
object currentStoreValue = null;
switch (location)
{
case StoreLocation.Raw:
currentStoreValue = info.RawValue;
AddValueToStoreValue <string>(info, value, ref currentStoreValue);
info.RawValue = currentStoreValue;
break;
case StoreLocation.Invalid:
currentStoreValue = info.InvalidValue;
AddValueToStoreValue <string>(info, value, ref currentStoreValue);
info.InvalidValue = currentStoreValue;
break;
case StoreLocation.Parsed:
Contract.Assert((value == null) || (!(value is List <object>)),
"Header value types must not derive from List<object> since this type is used internally to store " +
"lists of values. So we would not be able to distinguish between a single value and a list of values.");
currentStoreValue = info.ParsedValue;
AddValueToStoreValue <object>(info, value, ref currentStoreValue);
info.ParsedValue = currentStoreValue;
break;
default:
Contract.Assert(false, "Unknown StoreLocation value: " + location.ToString());
break;
}
}
private bool ParseRawHeaderValues(string name, HeaderStoreItemInfo info, bool removeEmptyHeader)
{
Contract.Ensures(info.RawValue == null);
// Unlike TryGetHeaderInfo() this method tries to parse all non-validated header values (if any)
// before returning to the caller.
if (info.RawValue != null)
{
List <string> rawValues = info.RawValue as List <string>;
if (rawValues == null)
{
ParseSingleRawHeaderValue(name, info);
}
else
{
ParseMultipleRawHeaderValues(name, info, rawValues);
}
// At this point all values are either in info.ParsedValue, info.InvalidValue, or were removed since they
// contain invalid newline chars. Reset RawValue.
info.RawValue = null;
// During parsing, we removed tha value since it contains invalid newline chars. Return false to indicate that
// this is an empty header. If the caller specified to remove empty headers, we'll remove the header before
// returning.
if ((info.InvalidValue == null) && (info.ParsedValue == null))
{
if (removeEmptyHeader)
{
// After parsing the raw value, no value is left because all values contain invalid newline
// chars.
Contract.Assert(headerStore != null);
headerStore.Remove(name);
}
return(false);
}
}
return(true);
}
public bool TryGetValues(string name, out IEnumerable <string> values)
{
CheckHeaderName(name);
if (headerStore == null)
{
values = null;
return(false);
}
HeaderStoreItemInfo info = null;
if (TryGetAndParseHeaderInfo(name, out info))
{
values = GetValuesAsStrings(info);
return(true);
}
values = null;
return(false);
}
private static void ParseSingleRawHeaderValue(string name, HeaderStoreItemInfo info)
{
string rawValue = info.RawValue as string;
Contract.Assert(rawValue != null, "RawValue must either be List<string> or string.");
if (info.Parser == null)
{
if (!ContainsInvalidNewLine(rawValue, name))
{
info.ParsedValue = info.RawValue;
}
}
else
{
if (!TryParseAndAddRawHeaderValue(name, info, rawValue))
{
// TODO log that we couldn't add invalid header value
}
}
}
private static string[] GetValuesAsStrings(HeaderStoreItemInfo info)
{
Contract.Ensures(Contract.Result <string[]>() != null);
int length = GetValueCount(info);
string[] values = new string[length];
if (length > 0)
{
int currentIndex = 0;
ReadStoreValues <string>(values, info.RawValue, null, ref currentIndex);
ReadStoreValues <object>(values, info.ParsedValue, info.Parser, ref currentIndex);
// Set parser parameter to 'null' for invalid values: The invalid values is always a string so we
// don't need the parser to "serialize" the value to a string.
ReadStoreValues <string>(values, info.InvalidValue, null, ref currentIndex);
}
return(values);
}
private static void ParseMultipleRawHeaderValues(string name, HeaderStoreItemInfo info, List <string> rawValues)
{
if (info.Parser == null)
{
foreach (string rawValue in rawValues)
{
if (!ContainsInvalidNewLine(rawValue, name))
{
AddValue(info, rawValue, StoreLocation.Parsed);
}
}
}
else
{
foreach (string rawValue in rawValues)
{
if (!TryParseAndAddRawHeaderValue(name, info, rawValue))
{
// TODO log that we couldn't add invalid header value
}
}
}
}
private void ParseAndAddValue(string name, HeaderStoreItemInfo info, string value)
{
Contract.Requires(info != null);
if (info.Parser == null)
{
// If we don't have a parser for the header, we consider the value valid if it doesn't contains
// invalid newline characters. We add the values as "parsed value". Note that we allow empty values.
CheckInvalidNewLine(value);
AddValue(info, value == null ? string.Empty : value, StoreLocation.Parsed);
return;
}
// If the header only supports 1 value, we can add the current value only if there is no
// value already set.
if (!info.CanAddValue)
{
throw new FormatException(string.Format("Cannot add value because header '{0}' does not support multiple values.", name));
}
int index = 0;
object parsedValue = info.Parser.ParseValue(value, info.ParsedValue, ref index);
// The raw string only represented one value (which was successfully parsed). Add the value and return.
// If value is null we still have to first call ParseValue() to allow the parser to decide whether null is
// a valid value. If it is (i.e. no exception thrown), we set the parsed value (if any) and return.
if ((value == null) || (index == value.Length))
{
// If the returned value is null, then it means the header accepts empty values. I.e. we don't throw
// but we don't add 'null' to the store either.
if (parsedValue != null)
{
AddValue(info, parsedValue, StoreLocation.Parsed);
}
return;
}
Contract.Assert(index < value.Length, "Parser must return an index value within the string length.");
// If we successfully parsed a value, but there are more left to read, store the results in a temp
// list. Only when all values are parsed successfully write the list to the store.
List <object> parsedValues = new List <object>();
if (parsedValue != null)
{
parsedValues.Add(parsedValue);
}
while (index < value.Length)
{
parsedValue = info.Parser.ParseValue(value, info.ParsedValue, ref index);
if (parsedValue != null)
{
parsedValues.Add(parsedValue);
}
}
// All values were parsed correctly. Copy results to the store.
foreach (object item in parsedValues)
{
AddValue(info, item, StoreLocation.Parsed);
}
}
private static bool TryParseAndAddRawHeaderValue(string name, HeaderStoreItemInfo info, string value)
{
Contract.Requires(info != null);
Contract.Requires(info.Parser != null);
Contract.Requires(value != null, "Trying to parse 'null': Raw values should never be 'null'.");
// Values are added as 'invalid' if we either can't parse the value OR if we already have a value
// and the current header doesn't support multiple values: e.g. trying to add a date/time value
// to the 'Date' header if we already have a date/time value will result in the second value being
// added to the 'invalid' header values.
if (!info.CanAddValue)
{
AddValue(info, value, StoreLocation.Invalid);
return(false);
}
int index = 0;
object parsedValue = null;
if (info.Parser.TryParseValue(value, info.ParsedValue, ref index, out parsedValue))
{
// The raw string only represented one value (which was successfully parsed). Add the value and return.
if (index == value.Length)
{
if (parsedValue != null)
{
AddValue(info, parsedValue, StoreLocation.Parsed);
}
return(true);
}
Contract.Assert(index < value.Length, "Parser must return an index value within the string length.");
// If we successfully parsed a value, but there are more left to read, store the results in a temp
// list. Only when all values are parsed successfully write the list to the store.
List <object> parsedValues = new List <object>();
if (parsedValue != null)
{
parsedValues.Add(parsedValue);
}
while (index < value.Length)
{
if (info.Parser.TryParseValue(value, info.ParsedValue, ref index, out parsedValue))
{
if (parsedValue != null)
{
parsedValues.Add(parsedValue);
}
}
else
{
if (!ContainsInvalidNewLine(value, name))
{
AddValue(info, value, StoreLocation.Invalid);
}
return(false);
}
}
// All values were parsed correctly. Copy results to the store.
foreach (object item in parsedValues)
{
AddValue(info, item, StoreLocation.Parsed);
}
return(true);
}
if (!ContainsInvalidNewLine(value, name))
{
AddValue(info, value, StoreLocation.Invalid);
}
return(false);
}
internal bool RemoveParsedValue(string name, object value)
{
Contract.Requires((name != null) && (name.Length > 0));
Contract.Requires(HttpRuleParser.GetTokenLength(name, 0) == name.Length);
Contract.Requires(value != null);
if (headerStore == null)
{
return(false);
}
// If we have a value for this header, then verify if we have a single value. If so, compare that
// value with 'item'. If we have a list of values, then remove 'item' from the list.
HeaderStoreItemInfo info = null;
if (TryGetAndParseHeaderInfo(name, out info))
{
Contract.Assert(info.Parser != null, "Can't add parsed value if there is no parser available.");
Contract.Assert(info.Parser.SupportsMultipleValues,
"This method should not be used for single-value headers. Use Remove(string) instead.");
bool result = false;
// If there is no entry, just return.
if (info.ParsedValue == null)
{
return(false);
}
IEqualityComparer comparer = info.Parser.Comparer;
List <object> parsedValues = info.ParsedValue as List <object>;
if (parsedValues == null)
{
Contract.Assert(info.ParsedValue.GetType() == value.GetType(),
"Stored value does not have the same type as 'value'.");
if (AreEqual(value, info.ParsedValue, comparer))
{
info.ParsedValue = null;
result = true;
}
}
else
{
foreach (object item in parsedValues)
{
Contract.Assert(item.GetType() == value.GetType(),
"One of the stored values does not have the same type as 'value'.");
if (AreEqual(value, item, comparer))
{
// Remove 'item' rather than 'value', since the 'comparer' may consider two values
// equal even though the default obj.Equals() may not (e.g. if 'comparer' does
// case-insentive comparison for strings, but string.Equals() is case-sensitive).
result = parsedValues.Remove(item);
break;
}
}
// If we removed the last item in a list, remove the list.
if (parsedValues.Count == 0)
{
info.ParsedValue = null;
}
}
// If there is no value for the header left, remove the header.
if (info.IsEmpty)
{
bool headerRemoved = Remove(name);
Contract.Assert(headerRemoved, "Existing header '" + name + "' couldn't be removed.");
}
return(result);
}
return(false);
}