/// <summary>
/// Finds the name of the closest symbol to an address
/// </summary>
/// <param name="address">The address</param>
/// <param name="addressOffset">A pointer to where to store the offset from this symbol</param>
/// <returns>The symbol name</returns>
public static string FindSymbolName(void *address, void **addressOffset)
{
void *table = getSymbolTable();
// Before the first entry, there's an int stored for the amount of entries
int entries = *(int *)table;
int tableOffset = sizeof(int);
// Find closest match
int distance = 0x7FFFFFFF;
string candidateName = null;
void * candidateOffset = null;
for (int i = 0; i < entries; i++)
{
// Get symbol info
Symbol *sym = (Symbol *)((int)table + tableOffset);
string symbolName = Util.CharPtrToString(&sym->Name);
int size = sizeof(void *) + symbolName.Length + 1;
// Distance from current symbol address to the address we search for
int currentDistance = (int)address - (int)sym->Address;
if (currentDistance < 0 || currentDistance > distance)
{
tableOffset += size;
continue;
}
candidateName = symbolName;
candidateOffset = (void *)currentDistance;
distance = currentDistance;
tableOffset += size;
}
*addressOffset = candidateOffset;
return(candidateName);
}
public override unsafe void CompressChunk(ReadOnlySpan <byte> chunk)
{
if (m_CompressOutput.IsEmpty)
{
return;
}
if (chunk.IsEmpty)
{
return;
fixed(byte *pChunk = chunk)
{
m_CompressContext->inData = pChunk;
m_CompressContext->inEnd = &pChunk[chunk.Length];
while (true)
{
Symbol *subcontext, symbol = null;
byte value;
ushort under = 0, total = 0, count = 0;
ushort *parent = &m_CompressContext->predicted;
if (m_CompressContext->inData >= m_CompressContext->inEnd)
{
break;
}
value = *m_CompressContext->inData++;
for (subcontext = &m_CompressContext->symbols[m_CompressContext->predicted];
subcontext != m_CompressContext->root;
subcontext = &m_CompressContext->symbols[subcontext->parent])
{
m_CompressContext->Encode(subcontext, ref symbol, value, ref under, ref count, ENET_SUBCONTEXT_SYMBOL_DELTA, 0);
*parent = (ushort)(symbol - m_CompressContext->symbols);
parent = &symbol->parent;
total = subcontext->total;
if (count > 0)
{
m_CompressContext->RangeCoderEncode((ushort)(subcontext->escapes + under), count, total);
}
else
{
if (subcontext->escapes > 0 && subcontext->escapes < total)
{
m_CompressContext->RangeCoderEncode(0, subcontext->escapes, total);
}
subcontext->escapes += ENET_SUBCONTEXT_ESCAPE_DELTA;
subcontext->total += ENET_SUBCONTEXT_ESCAPE_DELTA;
}
subcontext->total += ENET_SUBCONTEXT_SYMBOL_DELTA;
if (count > 0xFF - 2 * ENET_SUBCONTEXT_SYMBOL_DELTA || subcontext->total > ENET_RANGE_CODER_BOTTOM - 0x100)
{
m_CompressContext->Rescale(subcontext, 0);
}
if (count > 0)
{
goto nextInput;
}
}
m_CompressContext->Encode(m_CompressContext->root, ref symbol, value, ref under, ref count, ENET_CONTEXT_SYMBOL_DELTA, ENET_CONTEXT_SYMBOL_MINIMUM);
*parent = (ushort)(symbol - m_CompressContext->symbols);
parent = &symbol->parent;
total = m_CompressContext->root->total;
m_CompressContext->RangeCoderEncode((ushort)(m_CompressContext->root->escapes + under), count, total);
m_CompressContext->root->total += ENET_CONTEXT_SYMBOL_DELTA;
if (count > 0xFF - 2 * ENET_CONTEXT_SYMBOL_DELTA + ENET_CONTEXT_SYMBOL_MINIMUM || m_CompressContext->root->total > ENET_RANGE_CODER_BOTTOM - 0x100)
{
m_CompressContext->Rescale(m_CompressContext->root, ENET_CONTEXT_SYMBOL_MINIMUM);
}
nextInput:
if (m_CompressContext->order >= ENET_SUBCONTEXT_ORDER)
{
m_CompressContext->predicted = m_CompressContext->symbols[m_CompressContext->predicted].parent;
}
else
{
m_CompressContext->order++;
}
m_CompressContext->RangeCoderFreeSymbols();
}
}
}
/* Don't remove this, we may need it. */
/*static uint RangeCoderCompress(Symbol* context, byte* inBuffer, uint inBufferLen, byte* outData, uint outLimit)
* {
* if (context == null || inBuffer == null || outData == null)
* throw new ENetCompressionException("Bad compressor arguments.");
*
* unchecked
* {
* Context ctx = new()
* {
* symbols = context,
* outStart = outData,
* outEnd = &outData[outLimit],
* inData = inBuffer,
* outData = outData,
* inEnd = &inBuffer[inBufferLen],
* low = 0,
* range = (uint)~0,
* root = null,
* predicted = 0,
* order = 0,
* nextSymbol = 0,
* };
*
* ctx.Create(out ctx.root, ENET_CONTEXT_ESCAPE_MINIMUM, ENET_CONTEXT_SYMBOL_MINIMUM);
*
* while (true)
* {
* Symbol* subcontext, symbol = null;
* byte value;
* ushort under = 0, total = 0, count = 0;
* ushort* parent = &ctx.predicted;
* if (ctx.inData >= ctx.inEnd)
* break;
*
* value = *ctx.inData++;
*
* for (subcontext = &ctx.symbols[ctx.predicted];
* subcontext != ctx.root;
* subcontext = &ctx.symbols[subcontext->parent])
* {
* ctx.Encode(subcontext, ref symbol, value, ref under, ref count, ENET_SUBCONTEXT_SYMBOL_DELTA, 0);
*
* parent = (ushort)(symbol - ctx.symbols);
* parent = &symbol->parent;
* total = subcontext->total;
*
* if (count > 0)
* {
* ctx.RangeCoderEncode((ushort)(subcontext->escapes + under), count, total);
* }
* else
* {
* if (subcontext->escapes > 0 && subcontext->escapes < total)
* ctx.RangeCoderEncode(0, subcontext->escapes, total);
* subcontext->escapes += ENET_SUBCONTEXT_ESCAPE_DELTA;
* subcontext->total += ENET_SUBCONTEXT_ESCAPE_DELTA;
* }
* subcontext->total += ENET_SUBCONTEXT_SYMBOL_DELTA;
* if (count > 0xFF - 2 * ENET_SUBCONTEXT_SYMBOL_DELTA || subcontext->total > ENET_RANGE_CODER_BOTTOM - 0x100)
* ctx.Rescale(subcontext, 0);
* if (count > 0) goto nextInput;
* }
*
* ctx.Encode(ctx.root, ref symbol, value, ref under, ref count, ENET_CONTEXT_SYMBOL_DELTA, ENET_CONTEXT_SYMBOL_MINIMUM);
* parent = (ushort)(symbol - ctx.symbols);
* parent = &symbol->parent;
* total = ctx.root->total;
*
* ctx.RangeCoderEncode((ushort)(ctx.root->escapes + under), count, total);
* ctx.root->total += ENET_CONTEXT_SYMBOL_DELTA;
* if (count > 0xFF - 2 * ENET_CONTEXT_SYMBOL_DELTA + ENET_CONTEXT_SYMBOL_MINIMUM || ctx.root->total > ENET_RANGE_CODER_BOTTOM - 0x100)
* ctx.Rescale(ctx.root, ENET_CONTEXT_SYMBOL_MINIMUM);
*
* nextInput:
* if (ctx.order >= ENET_SUBCONTEXT_ORDER)
* ctx.predicted = ctx.symbols[ctx.predicted].parent;
* else
* ctx.order++;
* ctx.RangeCoderFreeSymbols();
* }
*
* ctx.RangeCoderFlush();
*
* return (uint)(ctx.outData - ctx.outStart);
* }
* }*/
static uint RangeCoderDecompress(Symbol *context, byte *inData, uint inLimit, byte *outData, uint outLimit)
{
if (context == null || inLimit <= 0)
throw new ENetCompressionException("Bad decompressor arguments."); }
public ENetRangeCoder()
{
m_Symbols = (Symbol *)Marshal.AllocHGlobal(sizeof(Symbol) * 4096);
m_CompressContext = (Context *)Marshal.AllocHGlobal(sizeof(Context));
}
