void RDG_genBlock(void* buffer, size_t buffSize, size_t prefixSize, double matchProba, void* litTable, unsigned* seedPtr)
{
BYTE* buffPtr = (BYTE*)buffer;
const U32 matchProba32 = (U32)(32768 * matchProba);
size_t pos = prefixSize;
void* ldctx = litTable;
U32* seed = seedPtr;
/* special case */
while (matchProba >= 1.0)
{
size_t size0 = RDG_rand(seed) & 3;
size0 = (size_t)1 << (16 + size0 * 2);
size0 += RDG_rand(seed) & (size0-1); /* because size0 is power of 2*/
if (buffSize < pos + size0)
{
memset(buffPtr+pos, 0, buffSize-pos);
return;
}
memset(buffPtr+pos, 0, size0);
pos += size0;
buffPtr[pos-1] = RDG_genChar(seed, ldctx);
}
/* init */
if (pos==0) buffPtr[0] = RDG_genChar(seed, ldctx), pos=1;
/* Generate compressible data */
while (pos < buffSize)
{
/* Select : Literal (char) or Match (within 32K) */
if (RDG_RAND15BITS < matchProba32)
{
/* Copy (within 32K) */
size_t match;
size_t d;
int length = RDG_RANDLENGTH + 4;
U32 offset = RDG_RAND15BITS + 1;
if (offset > pos) offset = (U32)pos;
match = pos - offset;
d = pos + length;
if (d > buffSize) d = buffSize;
while (pos < d) buffPtr[pos++] = buffPtr[match++];
}
else
{
/* Literal (noise) */
size_t d;
size_t length = RDG_RANDLENGTH;
d = pos + length;
if (d > buffSize) d = buffSize;
while (pos < d) buffPtr[pos++] = RDG_genChar(seed, ldctx);
}
}
}
void RDG_genBlock(void* buffer, size_t buffSize, size_t prefixSize, double matchProba, const BYTE* ldt, unsigned* seedPtr)
{
BYTE* const buffPtr = (BYTE*)buffer;
U32 const matchProba32 = (U32)(32768 * matchProba);
size_t pos = prefixSize;
U32 prevOffset = 1;
/* special case : sparse content */
while (matchProba >= 1.0) {
size_t size0 = RDG_rand(seedPtr) & 3;
size0 = (size_t)1 << (16 + size0 * 2);
size0 += RDG_rand(seedPtr) & (size0-1); /* because size0 is power of 2*/
if (buffSize < pos + size0) {
memset(buffPtr+pos, 0, buffSize-pos);
return;
}
memset(buffPtr+pos, 0, size0);
pos += size0;
buffPtr[pos-1] = RDG_genChar(seedPtr, ldt);
continue;
}
/* init */
if (pos==0) buffPtr[0] = RDG_genChar(seedPtr, ldt), pos=1;
/* Generate compressible data */
while (pos < buffSize) {
/* Select : Literal (char) or Match (within 32K) */
if (RDG_rand15Bits(seedPtr) < matchProba32) {
/* Copy (within 32K) */
U32 const length = RDG_randLength(seedPtr) + 4;
U32 const d = (U32) MIN(pos + length , buffSize);
U32 const repeatOffset = (RDG_rand(seedPtr) & 15) == 2;
U32 const randOffset = RDG_rand15Bits(seedPtr) + 1;
U32 const offset = repeatOffset ? prevOffset : (U32) MIN(randOffset , pos);
size_t match = pos - offset;
//TRACE("pos : %u; offset: %u ; length : %u \n", (U32)pos, offset, length);
while (pos < d) buffPtr[pos++] = buffPtr[match++]; /* correctly manages overlaps */
prevOffset = offset;
} else {
/* Literal (noise) */
U32 const length = RDG_randLength(seedPtr);
U32 const d = (U32) MIN(pos + length, buffSize);
while (pos < d) buffPtr[pos++] = RDG_genChar(seedPtr, ldt);
} }
}
