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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/GroupUInt32Codec.cs
+59 -67
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@@ -6,16 +6,6 @@ namespace Esiur.Data.Gvwie;
public static class GroupUInt32Codec
{
// Header layout:
// 1 | ccccc | ww
//
// MSB = 1 => grouped form
// ccccc = 0..30 => short count = ccccc + 1 (1..31)
// ccccc = 31 => extended count, followed by varint(count - 32)
// ww = 0..3 => width = ww + 1 (1..4)
//
// MSB = 0 => literal fast path for values in 7 bits
// ----------------- Encoder -----------------
public static byte[] Encode(IList<uint> values, bool aligned = false)
{
@@ -35,7 +25,7 @@ public static class GroupUInt32Codec
}
int start = i;
int width = WidthFromValue(v, aligned);
int width = WidthFromUInt32(v, aligned);
int count = 1;
// Build a run of same-width non-literal values
@@ -47,17 +37,18 @@ public static class GroupUInt32Codec
if (v2 <= 0x7Fu)
break;
int w2 = WidthFromValue(v2, aligned);
int w2 = WidthFromUInt32(v2, aligned);
if (w2 != width)
break;
count++;
}
if (count <= 31)
if (count <= 28)
{
// Short group:
// Header: 1 | (count-1)[5 bits] | (width-1)[2 bits]
// count field 00000..11011 => count 1..28
byte header = 0x80;
header |= (byte)(((count - 1) & 0x1F) << 2);
header |= (byte)((width - 1) & 0x03);
@@ -66,13 +57,33 @@ public static class GroupUInt32Codec
else
{
// Extended group:
// Header: 1 | 11111 | (width-1)[2 bits]
// Followed by varint(count - 32)
// Header: 1 | g[5 bits] | (width-1)[2 bits]
//
// g = 11100 => LoL = 1 byte
// g = 11101 => LoL = 2 bytes
// g = 11110 => LoL = 3 bytes
// g = 11111 => LoL = 4 bytes
//
// LoL stores (count - 29) in little-endian form.
uint extra = checked((uint)(count - 29));
int lol = LengthOfLength(extra);
byte groupBits = lol switch
{
1 => 0b11100,
2 => 0b11101,
3 => 0b11110,
4 => 0b11111,
_ => throw new InvalidOperationException("Invalid LoL.")
};
byte header = 0x80;
header |= 0x7C; // count bits = 11111
header |= (byte)(groupBits << 2);
header |= (byte)((width - 1) & 0x03);
dst.Add(header);
WriteVarUInt32(dst, (uint)(count - 32));
WriteLE(dst, extra, lol);
}
// Payload: 'count' values, LE, 'width' bytes each
@@ -97,30 +108,36 @@ public static class GroupUInt32Codec
if ((h & 0x80) == 0)
{
// Fast path: literal 7-bit unsigned value
// Fast path: 7-bit literal in low bits
result.Add((uint)(h & 0x7F));
continue;
}
int countField = (h >> 2) & 0x1F;
int width = (h & 0x03) + 1; // 1..4
int width = (h & 0x03) + 1;
int count;
if (countField == 31)
if (countField <= 27)
{
uint extra = ReadVarUInt32(src, ref pos);
count = checked(32 + (int)extra);
// Short group: 0..27 => count 1..28
count = countField + 1;
}
else
{
count = countField + 1;
// Extended group:
// 28 => LoL=1
// 29 => LoL=2
// 30 => LoL=3
// 31 => LoL=4
int lol = countField - 27;
uint extra = ReadLE(src, ref pos, lol);
count = checked(29 + (int)extra);
}
for (int j = 0; j < count; j++)
{
uint raw = (uint)ReadLE(src, ref pos, width);
result.Add(raw);
}
result.Add(ReadLE(src, ref pos, width));
}
return result.ToArray();
@@ -129,7 +146,7 @@ public static class GroupUInt32Codec
// ----------------- Helpers -----------------
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static int WidthFromValue(uint v, bool aligned = false)
private static int WidthFromUInt32(uint v, bool aligned = false)
{
if (v <= 0xFFu) return 1;
if (v <= 0xFFFFu) return 2;
@@ -137,6 +154,15 @@ public static class GroupUInt32Codec
return 4;
}
[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, uint value, int width)
{
@@ -145,49 +171,15 @@ public static class GroupUInt32Codec
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ulong ReadLE(ReadOnlySpan<byte> src, ref int pos, int width)
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.");
ulong v = 0;
uint v = 0;
for (int i = 0; i < width; i++)
v |= (ulong)src[pos++] << (8 * 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.");
}
}
}