commit 8d9f81bc9cdca3022ec3243145bf232fe4f28579 Author: George Kadianakis desnacked@riseup.net Date: Tue Mar 5 17:49:44 2019 +0200
prob_distr: Implement type-safe downcasting functions. --- src/lib/math/prob_distr.c | 133 ++++++++++++++++------------------------------ 1 file changed, 46 insertions(+), 87 deletions(-)
diff --git a/src/lib/math/prob_distr.c b/src/lib/math/prob_distr.c index c952dadc0..2dff9e76e 100644 --- a/src/lib/math/prob_distr.c +++ b/src/lib/math/prob_distr.c @@ -46,26 +46,27 @@
#include "lib/crypt_ops/crypto_rand.h" #include "lib/cc/ctassert.h" +#include "lib/log/util_bug.h"
#include <float.h> #include <math.h> #include <stddef.h>
-/** Validators for downcasting macros below */ -#define validate_container_of(PTR, TYPE, FIELD) \ - (0 * sizeof((PTR) - &((TYPE *)(((char *)(PTR)) - \ - offsetof(TYPE, FIELD)))->FIELD)) -#define validate_const_container_of(PTR, TYPE, FIELD) \ - (0 * sizeof((PTR) - &((const TYPE *)(((const char *)(PTR)) - \ - offsetof(TYPE, FIELD)))->FIELD)) -/** Downcasting macro */ -#define container_of(PTR, TYPE, FIELD) \ - ((TYPE *)(((char *)(PTR)) - offsetof(TYPE, FIELD)) \ - + validate_container_of(PTR, TYPE, FIELD)) -/** Constified downcasting macro */ -#define const_container_of(PTR, TYPE, FIELD) \ - ((const TYPE *)(((const char *)(PTR)) - offsetof(TYPE, FIELD)) \ - + validate_const_container_of(PTR, TYPE, FIELD)) +/** Declare a function that downcasts from a generic dist struct to the actual + * subtype probablity distribution it represents. */ +#define DECLARE_PROB_DISTR_DOWNCAST_FN(name) \ + static inline \ + const struct name * \ + dist_to_const_##name(const struct dist *obj) { \ + tor_assert(obj->ops == &name##_ops); \ + return SUBTYPE_P(obj, struct name, base); \ + } +DECLARE_PROB_DISTR_DOWNCAST_FN(uniform) +DECLARE_PROB_DISTR_DOWNCAST_FN(geometric) +DECLARE_PROB_DISTR_DOWNCAST_FN(logistic) +DECLARE_PROB_DISTR_DOWNCAST_FN(log_logistic) +DECLARE_PROB_DISTR_DOWNCAST_FN(genpareto) +DECLARE_PROB_DISTR_DOWNCAST_FN(weibull)
/** * Count number of one bits in 32-bit word. @@ -1360,8 +1361,7 @@ dist_isf(const struct dist *dist, double p) static double uniform_sample(const struct dist *dist) { - const struct uniform *U = const_container_of(dist, struct uniform, - base); + const struct uniform *U = dist_to_const_uniform(dist); double p0 = random_uniform_01();
return sample_uniform_interval(p0, U->a, U->b); @@ -1370,9 +1370,7 @@ uniform_sample(const struct dist *dist) static double uniform_cdf(const struct dist *dist, double x) { - const struct uniform *U = const_container_of(dist, struct uniform, - base); - + const struct uniform *U = dist_to_const_uniform(dist); if (x < U->a) return 0; else if (x < U->b) @@ -1384,8 +1382,7 @@ uniform_cdf(const struct dist *dist, double x) static double uniform_sf(const struct dist *dist, double x) { - const struct uniform *U = const_container_of(dist, struct uniform, - base); + const struct uniform *U = dist_to_const_uniform(dist);
if (x > U->b) return 0; @@ -1398,8 +1395,7 @@ uniform_sf(const struct dist *dist, double x) static double uniform_icdf(const struct dist *dist, double p) { - const struct uniform *U = const_container_of(dist, struct uniform, - base); + const struct uniform *U = dist_to_const_uniform(dist); double w = U->b - U->a;
return (p < 0.5 ? (U->a + w*p) : (U->b - w*(1 - p))); @@ -1408,8 +1404,7 @@ uniform_icdf(const struct dist *dist, double p) static double uniform_isf(const struct dist *dist, double p) { - const struct uniform *U = const_container_of(dist, struct uniform, - base); + const struct uniform *U = dist_to_const_uniform(dist); double w = U->b - U->a;
return (p < 0.5 ? (U->b - w*p) : (U->a + w*(1 - p))); @@ -1429,8 +1424,7 @@ const struct dist_ops uniform_ops = { static double logistic_sample(const struct dist *dist) { - const struct logistic *L = const_container_of(dist, struct logistic, - base); + const struct logistic *L = dist_to_const_logistic(dist); uint32_t s = crypto_rand_u32(); double t = random_uniform_01(); double p0 = random_uniform_01(); @@ -1441,36 +1435,28 @@ logistic_sample(const struct dist *dist) static double logistic_cdf(const struct dist *dist, double x) { - const struct logistic *L = const_container_of(dist, struct logistic, - base); - + const struct logistic *L = dist_to_const_logistic(dist); return cdf_logistic(x, L->mu, L->sigma); }
static double logistic_sf(const struct dist *dist, double x) { - const struct logistic *L = const_container_of(dist, struct logistic, - base); - + const struct logistic *L = dist_to_const_logistic(dist); return sf_logistic(x, L->mu, L->sigma); }
static double logistic_icdf(const struct dist *dist, double p) { - const struct logistic *L = const_container_of(dist, struct logistic, - base); - + const struct logistic *L = dist_to_const_logistic(dist); return icdf_logistic(p, L->mu, L->sigma); }
static double logistic_isf(const struct dist *dist, double p) { - const struct logistic *L = const_container_of(dist, struct logistic, - base); - + const struct logistic *L = dist_to_const_logistic(dist); return isf_logistic(p, L->mu, L->sigma); }
@@ -1488,8 +1474,7 @@ const struct dist_ops logistic_ops = { static double log_logistic_sample(const struct dist *dist) { - const struct log_logistic *LL = const_container_of(dist, struct - log_logistic, base); + const struct log_logistic *LL = dist_to_const_log_logistic(dist); uint32_t s = crypto_rand_u32(); double p0 = random_uniform_01();
@@ -1499,36 +1484,28 @@ log_logistic_sample(const struct dist *dist) static double log_logistic_cdf(const struct dist *dist, double x) { - const struct log_logistic *LL = const_container_of(dist, - struct log_logistic, base); - + const struct log_logistic *LL = dist_to_const_log_logistic(dist); return cdf_log_logistic(x, LL->alpha, LL->beta); }
static double log_logistic_sf(const struct dist *dist, double x) { - const struct log_logistic *LL = const_container_of(dist, - struct log_logistic, base); - + const struct log_logistic *LL = dist_to_const_log_logistic(dist); return sf_log_logistic(x, LL->alpha, LL->beta); }
static double log_logistic_icdf(const struct dist *dist, double p) { - const struct log_logistic *LL = const_container_of(dist, - struct log_logistic, base); - + const struct log_logistic *LL = dist_to_const_log_logistic(dist); return icdf_log_logistic(p, LL->alpha, LL->beta); }
static double log_logistic_isf(const struct dist *dist, double p) { - const struct log_logistic *LL = const_container_of(dist, - struct log_logistic, base); - + const struct log_logistic *LL = dist_to_const_log_logistic(dist); return isf_log_logistic(p, LL->alpha, LL->beta); }
@@ -1546,8 +1523,7 @@ const struct dist_ops log_logistic_ops = { static double weibull_sample(const struct dist *dist) { - const struct weibull *W = const_container_of(dist, struct weibull, - base); + const struct weibull *W = dist_to_const_weibull(dist); uint32_t s = crypto_rand_u32(); double p0 = random_uniform_01();
@@ -1557,36 +1533,28 @@ weibull_sample(const struct dist *dist) static double weibull_cdf(const struct dist *dist, double x) { - const struct weibull *W = const_container_of(dist, struct weibull, - base); - + const struct weibull *W = dist_to_const_weibull(dist); return cdf_weibull(x, W->lambda, W->k); }
static double weibull_sf(const struct dist *dist, double x) { - const struct weibull *W = const_container_of(dist, struct weibull, - base); - + const struct weibull *W = dist_to_const_weibull(dist); return sf_weibull(x, W->lambda, W->k); }
static double weibull_icdf(const struct dist *dist, double p) { - const struct weibull *W = const_container_of(dist, struct weibull, - base); - + const struct weibull *W = dist_to_const_weibull(dist); return icdf_weibull(p, W->lambda, W->k); }
static double weibull_isf(const struct dist *dist, double p) { - const struct weibull *W = const_container_of(dist, struct weibull, - base); - + const struct weibull *W = dist_to_const_weibull(dist); return isf_weibull(p, W->lambda, W->k); }
@@ -1604,8 +1572,7 @@ const struct dist_ops weibull_ops = { static double genpareto_sample(const struct dist *dist) { - const struct genpareto *GP = const_container_of(dist, struct genpareto, - base); + const struct genpareto *GP = dist_to_const_genpareto(dist); uint32_t s = crypto_rand_u32(); double p0 = random_uniform_01();
@@ -1615,36 +1582,28 @@ genpareto_sample(const struct dist *dist) static double genpareto_cdf(const struct dist *dist, double x) { - const struct genpareto *GP = const_container_of(dist, struct genpareto, - base); - + const struct genpareto *GP = dist_to_const_genpareto(dist); return cdf_genpareto(x, GP->mu, GP->sigma, GP->xi); }
static double genpareto_sf(const struct dist *dist, double x) { - const struct genpareto *GP = const_container_of(dist, struct genpareto, - base); - + const struct genpareto *GP = dist_to_const_genpareto(dist); return sf_genpareto(x, GP->mu, GP->sigma, GP->xi); }
static double genpareto_icdf(const struct dist *dist, double p) { - const struct genpareto *GP = const_container_of(dist, struct genpareto, - base); - + const struct genpareto *GP = dist_to_const_genpareto(dist); return icdf_genpareto(p, GP->mu, GP->sigma, GP->xi); }
static double genpareto_isf(const struct dist *dist, double p) { - const struct genpareto *GP = const_container_of(dist, struct genpareto, - base); - + const struct genpareto *GP = dist_to_const_genpareto(dist); return isf_genpareto(p, GP->mu, GP->sigma, GP->xi); }
@@ -1662,7 +1621,7 @@ const struct dist_ops genpareto_ops = { static double geometric_sample(const struct dist *dist) { - const struct geometric *G = const_container_of(dist, struct geometric, base); + const struct geometric *G = dist_to_const_geometric(dist); uint32_t s = crypto_rand_u32(); double p0 = random_uniform_01();
@@ -1672,7 +1631,7 @@ geometric_sample(const struct dist *dist) static double geometric_cdf(const struct dist *dist, double x) { - const struct geometric *G = const_container_of(dist, struct geometric, base); + const struct geometric *G = dist_to_const_geometric(dist);
if (x < 1) return 0; @@ -1683,7 +1642,7 @@ geometric_cdf(const struct dist *dist, double x) static double geometric_sf(const struct dist *dist, double x) { - const struct geometric *G = const_container_of(dist, struct geometric, base); + const struct geometric *G = dist_to_const_geometric(dist);
if (x < 1) return 0; @@ -1694,7 +1653,7 @@ geometric_sf(const struct dist *dist, double x) static double geometric_icdf(const struct dist *dist, double p) { - const struct geometric *G = const_container_of(dist, struct geometric, base); + const struct geometric *G = dist_to_const_geometric(dist);
return log1p(-p)/log1p(-G->p); } @@ -1702,7 +1661,7 @@ geometric_icdf(const struct dist *dist, double p) static double geometric_isf(const struct dist *dist, double p) { - const struct geometric *G = const_container_of(dist, struct geometric, base); + const struct geometric *G = dist_to_const_geometric(dist);
return log(p)/log1p(-G->p); }