/// <summary>
/// Serializes the specified code page to the specified stream.
/// </summary>
/// <param name="codePage">The code page to serialize.</param>
/// <param name="stream">The stream to serialize the code page to.</param>
public static void Serialize(CodePageEncoding codePage, Stream stream)
{
if (codePage == null)
{
throw new ArgumentNullException(nameof(codePage));
}
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
var buffer = new byte[1024];
buffer[0] = codePage._hasDoubleByteChars ? (byte)1 : (byte)0;
var length = codePage._cpToUni.Count;
var lengthBytes = BitConverter.GetBytes(length);
Array.Copy(lengthBytes, 0, buffer, 1, 4);
var head = 5;
void Flush()
{
if (head == 0)
{
return;
}
stream.Write(buffer, 0, head);
head = 0;
}
foreach (var kv in codePage._cpToUni)
{
if (head + 4 > buffer.Length)
{
Flush();
}
var val = (ushort)kv.Value;
var keyL = (byte)(kv.Key & 0xff);
var keyH = (byte)(kv.Key >> 8);
var valL = (byte)(val & 0xff);
var valH = (byte)(val >> 8);
buffer[head++] = keyL;
buffer[head++] = keyH;
buffer[head++] = valL;
buffer[head++] = valH;
}
Flush();
}
/// <summary>
/// Deserializes a code page.
/// </summary>
/// <param name="stream">The stream.</param>
/// <returns>The deserialized code page.</returns>
public static CodePageEncoding Deserialize(Stream stream)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
var result = new CodePageEncoding();
result._hasDoubleByteChars = stream.ReadByte() != 0;
var buffer = new byte[4 * 256];
stream.Read(buffer, 0, 4);
var length = BitConverter.ToInt32(buffer, 0);
var i = 0;
var head = 0;
void Read()
{
var max = (length - i) * 4;
var rd = Math.Min(max, buffer.Length);
if (rd != 0)
{
stream.Read(buffer, 0, rd);
}
head = 0;
}
Read();
for (; i < length; i++)
{
if (head == buffer.Length)
{
Read();
}
var keyL = buffer[head++];
var keyH = buffer[head++];
var valL = buffer[head++];
var valH = buffer[head++];
var key = (ushort)(keyL | (keyH << 8));
var val = (char)(ushort)(valL | (valH << 8));
result._cpToUni[key] = val;
result._uniToCp[val] = key;
}
return(result);
}
/// <summary>
/// Creates a new <see cref="CodePageEncoding" /> instance based on the data provided by the specified stream.
/// </summary>
/// <param name="stream">The steam to load the code page encoding from.</param>
/// <returns>The newly created encoding instance.</returns>
public static CodePageEncoding Load(Stream stream)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
var result = new CodePageEncoding();
using (var reader = new StreamReader(stream))
{
while (!reader.EndOfStream)
{
var line = reader.ReadLine();
var ln = line.Trim();
if (ln.StartsWith("#"))
{
continue;
}
var spl = ln.Split(' ', '\t');
string from = null, to = null;
foreach (var p in spl)
{
if (p.StartsWith("#"))
{
break;
}
if (from == null)
{
from = p;
}
else
{
to = p;
break;
}
}
if (string.IsNullOrWhiteSpace(from) || string.IsNullOrWhiteSpace(to))
{
continue;
}
try
{
var fromNum = System.Convert.ToUInt16(from, 16);
var toNum = System.Convert.ToUInt16(to, 16);
if (fromNum > 0xff)
{
result._hasDoubleByteChars = true;
}
result._cpToUni[fromNum] = (char)toNum;
result._uniToCp[(char)toNum] = fromNum;
}
catch (ArgumentOutOfRangeException)
{
}
}
}
return(result);
}
