zipf: needs inttypes.h

[fio.git] / lib / rand.c

diff --git a/lib/rand.c b/lib/rand.c
index 839a6a9476c82cedad1de30067ab06c776d750bd..a79fb9c17c321a94e8e4bcfe030193003c80d93f 100644 (file)
--- a/lib/rand.c
+++ b/lib/rand.c
@@ -33,44 +33,101 @@
 
 */
 
+#include <string.h>
 #include "rand.h"
 #include "../hash.h"
 
-struct frand_state __fio_rand_state;
-
 static inline int __seed(unsigned int x, unsigned int m)
 {
        return (x < m) ? x + m : x;
 }
 
+static void __init_rand(struct frand_state *state, unsigned int seed)
+{
+       int cranks = 6;
+
+#define LCG(x, seed)  ((x) * 69069 ^ (seed))
+
+       state->s1 = __seed(LCG((2^31) + (2^17) + (2^7), seed), 1);
+       state->s2 = __seed(LCG(state->s1, seed), 7);
+       state->s3 = __seed(LCG(state->s2, seed), 15);
+
+       while (cranks--)
+               __rand(state);
+}
+
 void init_rand(struct frand_state *state)
 {
-#define LCG(x)  ((x) * 69069)   /* super-duper LCG */
-
-       state->s1 = __seed(LCG((2^31) + (2^17) + (2^7)), 1);
-       state->s2 = __seed(LCG(state->s1), 7);
-       state->s3 = __seed(LCG(state->s2), 15);
-
-       __rand(state);
-       __rand(state);
-       __rand(state);
-       __rand(state);
-       __rand(state);
-       __rand(state);
+       __init_rand(state, 1);
 }
 
-void fill_random_buf(void *buf, unsigned int len)
+void init_rand_seed(struct frand_state *state, unsigned int seed)
 {
-       unsigned long r = __rand(&__fio_rand_state);
-       long *ptr = buf;
+       __init_rand(state, seed);
+}
 
-       if (sizeof(int) != sizeof(*ptr))
-               r *= (unsigned long) __rand(&__fio_rand_state);
+void __fill_random_buf(void *buf, unsigned int len, unsigned long seed)
+{
+       long *ptr = buf;
 
        while ((void *) ptr - buf < len) {
-               *ptr = r;
+               *ptr = seed;
                ptr++;
-               r *= GOLDEN_RATIO_PRIME;
-               r >>= 3;
+               seed *= GOLDEN_RATIO_PRIME;
+               seed >>= 3;
+       }
+}
+
+unsigned long fill_random_buf(struct frand_state *fs, void *buf,
+                             unsigned int len)
+{
+       unsigned long r = __rand(fs);
+
+       if (sizeof(int) != sizeof(long *))
+               r *= (unsigned long) __rand(fs);
+
+       __fill_random_buf(buf, len, r);
+       return r;
+}
+
+unsigned long fill_random_buf_percentage(struct frand_state *fs, void *buf,
+                                        unsigned int percentage,
+                                        unsigned int segment, unsigned int len)
+{
+       unsigned long r = __rand(fs);
+       unsigned int this_len;
+
+       if (percentage == 100) {
+               memset(buf, 0, len);
+               return 0;
        }
+
+       if (segment > len)
+               segment = len;
+
+       if (sizeof(int) != sizeof(long *))
+               r *= (unsigned long) __rand(fs);
+
+       while (len) {
+               /*
+                * Fill random chunk
+                */
+               this_len = (segment * (100 - percentage)) / 100;
+               if (this_len > len)
+                       this_len = len;
+
+               __fill_random_buf(buf, this_len, r);
+
+               len -= this_len;
+               buf += this_len;
+
+               if (this_len > len)
+                       this_len = len;
+
+               memset(buf, 0, this_len);
+               len -= this_len;
+               buf += this_len;
+       }
+
+       return r;
 }