sourcemod/public/sourcepawn/ke_utility.h

328 lines
6.7 KiB
C++

/* vim: set ts=4 sw=4 tw=99 et:
*
* Copyright (C) 2012-2013 David Anderson
*
* This file is part of SourcePawn.
*
* SourcePawn is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* SourcePawn is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* SourcePawn. If not, see http://www.gnu.org/licenses/.
*/
#ifndef _include_jitcraft_utility_h_
#define _include_jitcraft_utility_h_
#include <assert.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdint.h>
#if defined(_MSC_VER)
# include <intrin.h>
#endif
#define KE_32BIT
#if defined(_MSC_VER)
# pragma warning(disable:4355)
#endif
namespace ke {
static const size_t kMallocAlignment = sizeof(void *) * 2;
typedef uint8_t uint8;
typedef int32_t int32;
typedef uint32_t uint32;
typedef int64_t int64;
typedef uint64_t uint64;
typedef uint8 * Address;
static const size_t kKB = 1024;
static const size_t kMB = 1024 * kKB;
static const size_t kGB = 1024 * kMB;
template <typename T> T
ReturnAndVoid(T &t)
{
T saved = t;
t = T();
return saved;
}
// Wrapper that automatically deletes its contents. The pointer can be taken
// to avoid destruction.
template <typename T>
class AutoPtr
{
T *t_;
public:
AutoPtr()
: t_(NULL)
{
}
explicit AutoPtr(T *t)
: t_(t)
{
}
~AutoPtr() {
delete t_;
}
T *take() {
return ReturnAndVoid(t_);
}
T *operator *() const {
return t_;
}
T *operator ->() const {
return t_;
}
operator T *() const {
return t_;
}
void operator =(T *t) {
delete t_;
t_ = t;
}
bool operator !() const {
return !t_;
}
};
// Bob Jenkin's one-at-a-time hash function[1].
//
// [1] http://burtleburtle.net/bob/hash/doobs.html
class CharacterStreamHasher
{
uint32 hash;
public:
CharacterStreamHasher()
: hash(0)
{ }
void add(char c) {
hash += c;
hash += (hash << 10);
hash ^= (hash >> 6);
}
void add(const char *s, size_t length) {
for (size_t i = 0; i < length; i++)
add(s[i]);
}
uint32 result() {
hash += (hash << 3);
hash ^= (hash >> 11);
hash += (hash << 15);
return hash;
}
};
static inline uint32
HashCharSequence(const char *s, size_t length)
{
CharacterStreamHasher hasher;
hasher.add(s, length);
return hasher.result();
}
// From http://burtleburtle.net/bob/hash/integer.html
static inline uint32
HashInt32(int32 a)
{
a = (a ^ 61) ^ (a >> 16);
a = a + (a << 3);
a = a ^ (a >> 4);
a = a * 0x27d4eb2d;
a = a ^ (a >> 15);
return a;
}
// From http://www.cris.com/~Ttwang/tech/inthash.htm
static inline uint32
HashInt64(int64 key)
{
key = (~key) + (key << 18); // key = (key << 18) - key - 1;
key = key ^ (uint64(key) >> 31);
key = key * 21; // key = (key + (key << 2)) + (key << 4);
key = key ^ (uint64(key) >> 11);
key = key + (key << 6);
key = key ^ (uint64(key) >> 22);
return uint32(key);
}
static inline uint32
HashPointer(void *p)
{
#if defined(KE_32BIT)
return HashInt32(reinterpret_cast<int32>(p));
#elif defined(KE_64BIT)
return HashInt64(reinterpret_cast<int64>(p));
#endif
}
static inline size_t
Log2(size_t number)
{
assert(number != 0);
#ifdef _MSC_VER
unsigned long rval;
# ifdef _M_IX86
_BitScanReverse(&rval, number);
# elif _M_X64
_BitScanReverse64(&rval, number);
# endif
return rval;
#else
size_t bit;
asm("bsr %1, %0\n"
: "=r" (bit)
: "rm" (number));
return bit;
#endif
}
static inline size_t
FindRightmostBit(size_t number)
{
assert(number != 0);
#ifdef _MSC_VER
unsigned long rval;
# ifdef _M_IX86
_BitScanForward(&rval, number);
# elif _M_X64
_BitScanForward64(&rval, number);
# endif
return rval;
#else
size_t bit;
asm("bsf %1, %0\n"
: "=r" (bit)
: "rm" (number));
return bit;
#endif
}
static inline bool
IsPowerOfTwo(size_t value)
{
if (value == 0)
return false;
return !(value & (value - 1));
}
static inline size_t
Align(size_t count, size_t alignment)
{
assert(IsPowerOfTwo(alignment));
return count + (alignment - (count % alignment)) % alignment;
}
static inline bool
IsUint32AddSafe(unsigned a, unsigned b)
{
if (!a || !b)
return true;
size_t log2_a = Log2(a);
size_t log2_b = Log2(b);
return (log2_a < sizeof(unsigned) * 8) &&
(log2_b < sizeof(unsigned) * 8);
}
static inline bool
IsUintPtrAddSafe(size_t a, size_t b)
{
if (!a || !b)
return true;
size_t log2_a = Log2(a);
size_t log2_b = Log2(b);
return (log2_a < sizeof(size_t) * 8) &&
(log2_b < sizeof(size_t) * 8);
}
static inline bool
IsUint32MultiplySafe(unsigned a, unsigned b)
{
if (a <= 1 || b <= 1)
return true;
size_t log2_a = Log2(a);
size_t log2_b = Log2(b);
return log2_a + log2_b <= sizeof(unsigned) * 8;
}
static inline bool
IsUintPtrMultiplySafe(size_t a, size_t b)
{
if (a <= 1 || b <= 1)
return true;
size_t log2_a = Log2(a);
size_t log2_b = Log2(b);
return log2_a + log2_b <= sizeof(size_t) * 8;
}
#define ARRAY_LENGTH(array) (sizeof(array) / sizeof(array[0]))
#define STATIC_ASSERT(cond) extern int static_assert_f(int a[(cond) ? 1 : -1])
#define IS_ALIGNED(addr, alignment) (!(uintptr_t(addr) & ((alignment) - 1)))
template <typename T>
static inline bool
IsAligned(T addr, size_t alignment)
{
assert(IsPowerOfTwo(alignment));
return !(uintptr_t(addr) & (alignment - 1));
}
static inline Address
AlignedBase(Address addr, size_t alignment)
{
assert(IsPowerOfTwo(alignment));
return Address(uintptr_t(addr) & ~(alignment - 1));
}
template <typename T> static inline T
Min(const T &t1, const T &t2)
{
return t1 < t2 ? t1 : t2;
}
template <typename T> static inline T
Max(const T &t1, const T &t2)
{
return t1 > t2 ? t1 : t2;
}
#define OFFSETOF(Class, Member) reinterpret_cast<size_t>(&((Class *)NULL)->Member)
#if defined(_MSC_VER)
# define KE_SIZET_FMT "%Iu"
#elif defined(__GNUC__)
# define KE_SIZET_FMT "%zu"
#else
# error "Implement format specifier string"
#endif
#if defined(__GNUC__)
# define KE_CRITICAL_LIKELY(x) __builtin_expect(!!(x), 1)
#else
# define KE_CRITICAL_LIKELY(x) x
#endif
}
#endif // _include_jitcraft_utility_h_