BinaryWriterWith7BitEncoding & BinaryReaderWith7BitEncoding
Mr. Ayende wrote in his latest blog post about an implementation of a queue. In the post he's using two magical files: BinaryWriterWith7BitEncoding & BinaryReaderWith7BitEncoding
BinaryWriterWith7BitEncoding
can write both int and long? using the following method sig开发者_如何学Gonatures: void WriteBitEncodedNullableInt64(long? value)
& void Write7BitEncodedInt(int value)
and
BinaryReaderWith7BitEncoding
can read the values written using the following method signatures: long? ReadBitEncodedNullableInt64()
and int Read7BitEncodedInt()
So far I've only managed to find a way to read the 7BitEncodedInt:
protected int Read7BitEncodedInt()
{
int value = 0;
int byteval;
int shift = 0;
while(((byteval = ReadByte()) & 0x80) != 0)
{
value |= ((byteval & 0x7F) << shift);
shift += 7;
}
return (value | (byteval << shift));
}
I'm not too good with byte shifting - does anybody know how to read and write the 7BitEncoded long? and write the int ?
Here's something like the write:
static void Write7BitEncodedInt32(Stream dest, int value)
{
Write7BitEncodedUInt32(dest, (uint) value);
}
static void Write7BitEncodedUInt32(Stream dest, uint value)
{
if(value < 128) { dest.WriteByte((byte)value); return;}
while(value != 0)
{
byte b = (byte) (value & 0x7F);
value >>= 7; // since uint, we'll eventually run out of 1s
if (value != 0) b |= 0x80; // and there's more
dest.WriteByte(b);
}
}
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