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Gvwie updated

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This commit is contained in:
ahmed
2026-04-09 16:36:05 +03:00
parent 15479288cc
commit ae524f577a
9 changed files with 575 additions and 509 deletions
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Libraries/Esiur/Data/Gvwie/GroupInt16Codec.cs
+60 -59
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@@ -6,17 +6,6 @@ namespace Esiur.Data.Gvwie;
public static class GroupInt16Codec
{
// Header layout:
// 1 | cccccc | w
//
// MSB = 1 => grouped form
// cccccc = 0..62 => short count = cccccc + 1 (1..63)
// cccccc = 63 => extended count, followed by varint(count - 64)
// w = 0 => width = 1 byte
// w = 1 => width = 2 bytes
//
// MSB = 0 => literal fast path for ZigZag values in 7 bits
// ----------------- Encoder -----------------
public static byte[] Encode(IList<short> values)
{
@@ -36,7 +25,7 @@ public static class GroupInt16Codec
}
int start = i;
int width = WidthFromZigZag(zz); // 1 or 2
int width = WidthFromZigZag(zz); // 1..2
int count = 1;
// Build a run of same-width non-literal values
@@ -55,10 +44,11 @@ public static class GroupInt16Codec
count++;
}
if (count <= 63)
if (count <= 60)
{
// Short group:
// Header: 1 | (count-1)[6 bits] | (width-1)[1 bit]
// count field 000000..111011 => count 1..60
byte header = 0x80;
header |= (byte)(((count - 1) & 0x3F) << 1);
header |= (byte)((width - 1) & 0x01);
@@ -67,13 +57,33 @@ public static class GroupInt16Codec
else
{
// Extended group:
// Header: 1 | 111111 | (width-1)[1 bit]
// Followed by varint(count - 64)
// Header: 1 | g[6 bits] | (width-1)[1 bit]
//
// g = 111100 => LoL = 1 byte
// g = 111101 => LoL = 2 bytes
// g = 111110 => LoL = 3 bytes
// g = 111111 => LoL = 4 bytes
//
// LoL stores (count - 61) in little-endian form.
uint extra = checked((uint)(count - 61));
int lol = LengthOfLength(extra);
byte groupBits = lol switch
{
1 => 0b111100,
2 => 0b111101,
3 => 0b111110,
4 => 0b111111,
_ => throw new InvalidOperationException("Invalid LoL.")
};
byte header = 0x80;
header |= 0x7E; // count bits = 111111
header |= (byte)(groupBits << 1);
header |= (byte)((width - 1) & 0x01);
dst.Add(header);
WriteVarUInt32(dst, (uint)(count - 64));
WriteLE(dst, extra, lol);
}
// Payload: 'count' zigzag values, LE, 'width' bytes each
@@ -98,24 +108,33 @@ public static class GroupInt16Codec
if ((h & 0x80) == 0)
{
// Fast path: 7-bit ZigZag in low bits
// Fast path: 7-bit zigzag in low bits
ushort zz7 = (ushort)(h & 0x7F);
result.Add(UnZigZag16(zz7));
continue;
}
int countField = (h >> 1) & 0x3F;
int width = (h & 0x01) + 1; // 1 or 2
int width = (h & 0x01) + 1;
int count;
if (countField == 63)
if (countField <= 59)
{
uint extra = ReadVarUInt32(src, ref pos);
count = checked(64 + (int)extra);
// Short group: 0..59 => count 1..60
count = countField + 1;
}
else
{
count = countField + 1;
// Extended group:
// 60 => LoL=1
// 61 => LoL=2
// 62 => LoL=3
// 63 => LoL=4
int lol = countField - 59;
uint extra = checked((uint)ReadLE(src, ref pos, lol));
count = checked(61 + (int)extra);
}
for (int j = 0; j < count; j++)
@@ -142,6 +161,15 @@ public static class GroupInt16Codec
return z <= 0xFF ? 1 : 2;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static int LengthOfLength(uint value)
{
if (value <= 0xFFu) return 1;
if (value <= 0xFFFFu) return 2;
if (value <= 0xFFFFFFu) return 3;
return 4;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void WriteLE(List<byte> dst, ushort value, int width)
{
@@ -149,50 +177,23 @@ public static class GroupInt16Codec
dst.Add((byte)((value >> (8 * i)) & 0xFF));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void WriteLE(List<byte> dst, uint value, int width)
{
for (int i = 0; i < width; i++)
dst.Add((byte)((value >> (8 * i)) & 0xFF));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static uint ReadLE(ReadOnlySpan<byte> src, ref int pos, int width)
{
if ((uint)(pos + width) > (uint)src.Length)
throw new ArgumentException("Buffer underflow while reading group payload.");
throw new ArgumentException("Buffer underflow while reading payload.");
uint v = 0;
for (int i = 0; i < width; i++)
v |= (uint)src[pos++] << (8 * i);
return v;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void WriteVarUInt32(List<byte> dst, uint value)
{
while (value >= 0x80)
{
dst.Add((byte)((value & 0x7F) | 0x80));
value >>= 7;
}
dst.Add((byte)value);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static uint ReadVarUInt32(ReadOnlySpan<byte> src, ref int pos)
{
uint result = 0;
int shift = 0;
while (true)
{
if (pos >= src.Length)
throw new ArgumentException("Buffer underflow while reading varint.");
byte b = src[pos++];
result |= (uint)(b & 0x7F) << shift;
if ((b & 0x80) == 0)
return result;
shift += 7;
if (shift >= 35)
throw new ArgumentException("Varint is too long for UInt32.");
}
}
}