[tor-commits] [tor/master] prob_distr: Implement type-safe downcasting functions.
teor at torproject.org
teor at torproject.org
Fri Mar 22 03:11:29 UTC 2019
commit 8d9f81bc9cdca3022ec3243145bf232fe4f28579
Author: George Kadianakis <desnacked at 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);
}
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