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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Collections;
using System.Collections.Specialized;
using System.Text;
namespace System.Runtime
{
//copied from System.Web.HttpUtility code (renamed here) to remove dependency on System.Web.dll
internal static class UrlUtility
{
private static Encoding s_asciiEncoding;
private static Encoding AsciiEncoding
{
get
{
if (s_asciiEncoding == null)
{
s_asciiEncoding = Encoding.GetEncoding("ascii");
}
return s_asciiEncoding;
}
}
// Query string parsing support
public static NameValueCollection ParseQueryString(string query)
{
return ParseQueryString(query, Encoding.UTF8);
}
public static NameValueCollection ParseQueryString(string query, Encoding encoding)
{
if (query == null)
{
throw Fx.Exception.ArgumentNull("query");
}
if (encoding == null)
{
throw Fx.Exception.ArgumentNull("encoding");
}
if (query.Length > 0 && query[0] == '?')
{
query = query.Substring(1);
}
return new HttpValueCollection(query, encoding);
}
public static string UrlEncode(string str)
{
if (str == null)
{
return null;
}
return UrlEncode(str, Encoding.UTF8);
}
// URL encodes a path portion of a URL string and returns the encoded string.
public static string UrlPathEncode(string str)
{
if (str == null)
{
return null;
}
// recurse in case there is a query string
int i = str.IndexOf('?');
if (i >= 0)
{
return UrlPathEncode(str.Substring(0, i)) + str.Substring(i);
}
// encode DBCS characters and spaces only
return UrlEncodeSpaces(UrlEncodeNonAscii(str, Encoding.UTF8));
}
public static string UrlEncode(string str, Encoding encoding)
{
if (str == null)
{
return null;
}
var bytes = UrlEncodeToBytes(str, encoding);
return AsciiEncoding.GetString(bytes, 0, bytes.Length);
}
public static string UrlEncodeUnicode(string str)
{
if (str == null)
return null;
return UrlEncodeUnicodeStringToStringInternal(str, false);
}
private static string UrlEncodeUnicodeStringToStringInternal(string s, bool ignoreAscii)
{
int l = s.Length;
StringBuilder sb = new StringBuilder(l);
for (int i = 0; i < l; i++)
{
char ch = s[i];
if ((ch & 0xff80) == 0)
{ // 7 bit?
if (ignoreAscii || IsSafe(ch))
{
sb.Append(ch);
}
else if (ch == ' ')
{
sb.Append('+');
}
else
{
sb.Append('%');
sb.Append(IntToHex((ch >> 4) & 0xf));
sb.Append(IntToHex((ch) & 0xf));
}
}
else
{ // arbitrary Unicode?
sb.Append("%u");
sb.Append(IntToHex((ch >> 12) & 0xf));
sb.Append(IntToHex((ch >> 8) & 0xf));
sb.Append(IntToHex((ch >> 4) & 0xf));
sb.Append(IntToHex((ch) & 0xf));
}
}
return sb.ToString();
}
// Helper to encode the non-ASCII url characters only
private static string UrlEncodeNonAscii(string str, Encoding e)
{
if (string.IsNullOrEmpty(str))
{
return str;
}
if (e == null)
{
e = Encoding.UTF8;
}
byte[] bytes = e.GetBytes(str);
bytes = UrlEncodeBytesToBytesInternalNonAscii(bytes, 0, bytes.Length, false);
return AsciiEncoding.GetString(bytes, 0, bytes.Length);
}
// Helper to encode spaces only
private static string UrlEncodeSpaces(string str)
{
if (str != null && str.IndexOf(' ') >= 0)
{
str = str.Replace(" ", "%20");
}
return str;
}
public static byte[] UrlEncodeToBytes(string str, Encoding e)
{
if (str == null)
{
return null;
}
byte[] bytes = e.GetBytes(str);
return UrlEncodeBytesToBytesInternal(bytes, 0, bytes.Length, false);
}
public static string UrlDecode(string str, Encoding e)
{
if (str == null)
{
return null;
}
return UrlDecodeStringFromStringInternal(str, e);
}
// Implementation for encoding
private static byte[] UrlEncodeBytesToBytesInternal(byte[] bytes, int offset, int count, bool alwaysCreateReturnValue)
{
int cSpaces = 0;
int cUnsafe = 0;
// count them first
for (int i = 0; i < count; i++)
{
char ch = (char)bytes[offset + i];
if (ch == ' ')
{
cSpaces++;
}
else if (!IsSafe(ch))
{
cUnsafe++;
}
}
// nothing to expand?
if (!alwaysCreateReturnValue && cSpaces == 0 && cUnsafe == 0)
{
return bytes;
}
// expand not 'safe' characters into %XX, spaces to +s
byte[] expandedBytes = new byte[count + cUnsafe * 2];
int pos = 0;
for (int i = 0; i < count; i++)
{
byte b = bytes[offset + i];
char ch = (char)b;
if (IsSafe(ch))
{
expandedBytes[pos++] = b;
}
else if (ch == ' ')
{
expandedBytes[pos++] = (byte)'+';
}
else
{
expandedBytes[pos++] = (byte)'%';
expandedBytes[pos++] = (byte)IntToHex((b >> 4) & 0xf);
expandedBytes[pos++] = (byte)IntToHex(b & 0x0f);
}
}
return expandedBytes;
}
private static bool IsNonAsciiByte(byte b)
{
return (b >= 0x7F || b < 0x20);
}
private static byte[] UrlEncodeBytesToBytesInternalNonAscii(byte[] bytes, int offset, int count, bool alwaysCreateReturnValue)
{
int cNonAscii = 0;
// count them first
for (int i = 0; i < count; i++)
{
if (IsNonAsciiByte(bytes[offset + i]))
{
cNonAscii++;
}
}
// nothing to expand?
if (!alwaysCreateReturnValue && cNonAscii == 0)
{
return bytes;
}
// expand not 'safe' characters into %XX, spaces to +s
byte[] expandedBytes = new byte[count + cNonAscii * 2];
int pos = 0;
for (int i = 0; i < count; i++)
{
byte b = bytes[offset + i];
if (IsNonAsciiByte(b))
{
expandedBytes[pos++] = (byte)'%';
expandedBytes[pos++] = (byte)IntToHex((b >> 4) & 0xf);
expandedBytes[pos++] = (byte)IntToHex(b & 0x0f);
}
else
{
expandedBytes[pos++] = b;
}
}
return expandedBytes;
}
private static string UrlDecodeStringFromStringInternal(string s, Encoding e)
{
int count = s.Length;
UrlDecoder helper = new UrlDecoder(count, e);
// go through the string's chars collapsing %XX and %uXXXX and
// appending each char as char, with exception of %XX constructs
// that are appended as bytes
for (int pos = 0; pos < count; pos++)
{
char ch = s[pos];
if (ch == '+')
{
ch = ' ';
}
else if (ch == '%' && pos < count - 2)
{
if (s[pos + 1] == 'u' && pos < count - 5)
{
int h1 = HexToInt(s[pos + 2]);
int h2 = HexToInt(s[pos + 3]);
int h3 = HexToInt(s[pos + 4]);
int h4 = HexToInt(s[pos + 5]);
if (h1 >= 0 && h2 >= 0 && h3 >= 0 && h4 >= 0)
{ // valid 4 hex chars
ch = (char)((h1 << 12) | (h2 << 8) | (h3 << 4) | h4);
pos += 5;
// only add as char
helper.AddChar(ch);
continue;
}
}
else
{
int h1 = HexToInt(s[pos + 1]);
int h2 = HexToInt(s[pos + 2]);
if (h1 >= 0 && h2 >= 0)
{ // valid 2 hex chars
byte b = (byte)((h1 << 4) | h2);
pos += 2;
// don't add as char
helper.AddByte(b);
continue;
}
}
}
if ((ch & 0xFF80) == 0)
{
helper.AddByte((byte)ch); // 7 bit have to go as bytes because of Unicode
}
else
{
helper.AddChar(ch);
}
}
return helper.GetString();
}
// Private helpers for URL encoding/decoding
private static int HexToInt(char h)
{
return (h >= '0' && h <= '9') ? h - '0' :
(h >= 'a' && h <= 'f') ? h - 'a' + 10 :
(h >= 'A' && h <= 'F') ? h - 'A' + 10 :
-1;
}
private static char IntToHex(int n)
{
//WCF CHANGE: CHANGED FROM Debug.Assert() to Fx.Assert()
Fx.Assert(n < 0x10, "n < 0x10");
if (n <= 9)
{
return (char)(n + (int)'0');
}
else
{
return (char)(n - 10 + (int)'a');
}
}
// Set of safe chars, from RFC 1738.4 minus '+'
internal static bool IsSafe(char ch)
{
if (ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' || ch >= '0' && ch <= '9')
{
return true;
}
switch (ch)
{
case '-':
case '_':
case '.':
case '!':
case '*':
case '\'':
case '(':
case ')':
return true;
}
return false;
}
// Internal class to facilitate URL decoding -- keeps char buffer and byte buffer, allows appending of either chars or bytes
internal class UrlDecoder
{
private int _bufferSize;
// Accumulate characters in a special array
private int _numChars;
private char[] _charBuffer;
// Accumulate bytes for decoding into characters in a special array
private int _numBytes;
private byte[] _byteBuffer;
// Encoding to convert chars to bytes
private Encoding _encoding;
private void FlushBytes()
{
if (_numBytes > 0)
{
_numChars += _encoding.GetChars(_byteBuffer, 0, _numBytes, _charBuffer, _numChars);
_numBytes = 0;
}
}
internal UrlDecoder(int bufferSize, Encoding encoding)
{
_bufferSize = bufferSize;
_encoding = encoding;
_charBuffer = new char[bufferSize];
// byte buffer created on demand
}
internal void AddChar(char ch)
{
if (_numBytes > 0)
{
FlushBytes();
}
_charBuffer[_numChars++] = ch;
}
internal void AddByte(byte b)
{
// if there are no pending bytes treat 7 bit bytes as characters
// this optimization is temp disable as it doesn't work for some encodings
//if (_numBytes == 0 && ((b & 0x80) == 0)) {
// AddChar((char)b);
//}
//else
{
if (_byteBuffer == null)
{
_byteBuffer = new byte[_bufferSize];
}
_byteBuffer[_numBytes++] = b;
}
}
internal string GetString()
{
if (_numBytes > 0)
{
FlushBytes();
}
if (_numChars > 0)
{
return new String(_charBuffer, 0, _numChars);
}
else
{
return string.Empty;
}
}
}
internal class HttpValueCollection : NameValueCollection
{
internal HttpValueCollection(string str, Encoding encoding)
: base(StringComparer.OrdinalIgnoreCase)
{
if (!string.IsNullOrEmpty(str))
{
FillFromString(str, true, encoding);
}
IsReadOnly = false;
}
internal void FillFromString(string s, bool urlencoded, Encoding encoding)
{
int l = (s != null) ? s.Length : 0;
int i = 0;
while (i < l)
{
// find next & while noting first = on the way (and if there are more)
int si = i;
int ti = -1;
while (i < l)
{
char ch = s[i];
if (ch == '=')
{
if (ti < 0)
ti = i;
}
else if (ch == '&')
{
break;
}
i++;
}
// extract the name / value pair
string name = null;
string value = null;
if (ti >= 0)
{
name = s.Substring(si, ti - si);
value = s.Substring(ti + 1, i - ti - 1);
}
else
{
value = s.Substring(si, i - si);
}
// add name / value pair to the collection
if (urlencoded)
{
base.Add(
UrlUtility.UrlDecode(name, encoding),
UrlUtility.UrlDecode(value, encoding));
}
else
{
base.Add(name, value);
}
// trailing '&'
if (i == l - 1 && s[i] == '&')
{
base.Add(null, string.Empty);
}
i++;
}
}
public override string ToString()
{
return ToString(true, null);
}
private string ToString(bool urlencoded, IDictionary excludeKeys)
{
int n = Count;
if (n == 0)
return string.Empty;
StringBuilder s = new StringBuilder();
string key, keyPrefix, item;
for (int i = 0; i < n; i++)
{
key = GetKey(i);
if (excludeKeys != null && key != null && excludeKeys[key] != null)
{
continue;
}
if (urlencoded)
{
key = UrlUtility.UrlEncodeUnicode(key);
}
keyPrefix = (!string.IsNullOrEmpty(key)) ? (key + "=") : string.Empty;
ArrayList values = (ArrayList)BaseGet(i);
int numValues = (values != null) ? values.Count : 0;
if (s.Length > 0)
{
s.Append('&');
}
if (numValues == 1)
{
s.Append(keyPrefix);
item = (string)values[0];
if (urlencoded)
item = UrlUtility.UrlEncodeUnicode(item);
s.Append(item);
}
else if (numValues == 0)
{
s.Append(keyPrefix);
}
else
{
for (int j = 0; j < numValues; j++)
{
if (j > 0)
{
s.Append('&');
}
s.Append(keyPrefix);
item = (string)values[j];
if (urlencoded)
{
item = UrlUtility.UrlEncodeUnicode(item);
}
s.Append(item);
}
}
}
return s.ToString();
}
}
}
}
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