diff options
Diffstat (limited to 'programs/datagen.c')
| -rw-r--r-- | programs/datagen.c | 44 |
1 files changed, 37 insertions, 7 deletions
diff --git a/programs/datagen.c b/programs/datagen.c index 05eb7f0..0109d54 100644 --- a/programs/datagen.c +++ b/programs/datagen.c @@ -109,30 +109,58 @@ static unsigned int CDG_rand(U32* src) #define CDG_RANDCHAR (((CDG_rand(seed) >> 9) & 63) + '0') static void CDG_generate(U64 size, U32* seed, double proba) { - BYTE buff[128 KB + 1]; + BYTE fullbuff[32 KB + 128 KB + 1]; + BYTE* buff = fullbuff + 32 KB; U64 total=0; U32 P32 = (U32)(32768 * proba); U32 pos=0; U32 genBlockSize = 128 KB; + // Build initial prefix + while (pos<32 KB) + { + // Select : Literal (char) or Match (within 32K) + if (CDG_RAND15BITS < P32) + { + // Copy (within 64K) + U32 d; + int ref; + int length = CDG_RANDLENGTH + 4; + U32 offset = CDG_RAND15BITS + 1; + if (offset > pos) offset = pos; + ref = pos - offset; + d = pos + length; + while (pos < d) fullbuff[pos++] = fullbuff[ref++]; + } + else + { + // Literal (noise) + U32 d; + int length = CDG_RANDLENGTH; + d = pos + length; + while (pos < d) fullbuff[pos++] = CDG_RANDCHAR; + } + } + + // Generate compressible data + pos = 0; while (total < size) { if (size-total < 128 KB) genBlockSize = (U32)(size-total); total += genBlockSize; buff[genBlockSize] = 0; - *buff = CDG_RANDCHAR; - pos = 1; + pos = 0; while (pos<genBlockSize) { // Select : Literal (char) or Match (within 32K) if (CDG_RAND15BITS < P32) { // Copy (within 64K) - U32 ref, d; + int ref; + U32 d; int length = CDG_RANDLENGTH + 4; U32 offset = CDG_RAND15BITS + 1; - if (offset > pos) offset = pos; - if (pos + length > 128 KB ) length = 128 KB - pos; + if (pos + length > genBlockSize ) length = genBlockSize - pos; ref = pos - offset; d = pos + length; while (pos < d) buff[pos++] = buff[ref++]; @@ -142,7 +170,7 @@ static void CDG_generate(U64 size, U32* seed, double proba) // Literal (noise) U32 d; int length = CDG_RANDLENGTH; - if (pos + length > 128 KB) length = 128 KB - pos; + if (pos + length > genBlockSize) length = genBlockSize - pos; d = pos + length; while (pos < d) buff[pos++] = CDG_RANDCHAR; } @@ -150,6 +178,8 @@ static void CDG_generate(U64 size, U32* seed, double proba) pos=0; for (;pos+512<=genBlockSize;pos+=512) printf("%512.512s", buff+pos); for (;pos<genBlockSize;pos++) printf("%c", buff[pos]); + // Regenerate prefix + memcpy(fullbuff, buff + 96 KB, 32 KB); } } |