utils.hh

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 // This Source Code Form is licensed MPL-2.0: http://mozilla.org/MPL/2.0
#ifndef __ASE_UTILS_HH__
#define __ASE_UTILS_HH__
 
#include <ase/defs.hh>
#include <ase/logging.hh>
#include <experimental/type_traits>
#include <any>
 
namespace Ase {
 
// == misc ==
const char*                                ase_gettext (const String &untranslated);
template<class A0, class... Ar> const char* ase_gettext (const char *format, const A0 &a0, const Ar &...restargs) ASE_PRINTF (1, 0);
 
// == Date & Time ==
String  now_strftime  (const String &format);
 
// == MakeIcon ==
namespace MakeIcon {
IconString KwIcon  (const String &keywords);
IconString UcIcon  (const String &unicode);
IconString SvgIcon (const String &svgdata);
IconString operator""_uc (const char *key, size_t);
IconString operator""_icon (const char *key, size_t);
} // MakeIcon
 
// == Jump Tables ==
template<typename MkFun, size_t ...INDICES> static auto
make_indexed_table (const MkFun &mkjump, std::index_sequence<INDICES...>)
{
  constexpr size_t N = sizeof... (INDICES);
  using Fun = decltype (mkjump (std::integral_constant<std::size_t, N - 1>()));
  const std::array<Fun, N> jumptable = {
    mkjump (std::integral_constant<std::size_t, INDICES>{})...
  };
  return jumptable;
}
 
template<std::size_t LAST, typename MkFun> static auto
make_case_table (const MkFun &mkjump)
{
  return make_indexed_table (mkjump, std::make_index_sequence<LAST + 1>());
}
 
// == EventFd ==
class EventFd
{
  int      fds[2];
  void     operator= (const EventFd&) = delete; // no assignments
  explicit EventFd   (const EventFd&) = delete; // no copying
public:
  explicit EventFd   ();
  int      open      (); 
  bool     opened    (); 
  void     wakeup    (); 
  int      inputfd   (); 
  bool     pollin    (); 
  void     flush     (); 
  /*Des*/ ~EventFd   ();
};
 
// == CustomData ==
template<typename T>
class CustomDataKey : public VirtualBase {
  /*Copy*/              CustomDataKey (const CustomDataKey&) = delete;
  CustomDataKey&        operator=     (const CustomDataKey&) = delete;
public:
  explicit          CustomDataKey () = default;
  virtual T             fallback  ()                    { return {}; }         
  const std::type_info& type      () const noexcept     { return typeid (T); } 
  bool                  has_value (const std::any &any) { return any.has_value() && any.type() == type(); }
  T                     extract   (const std::any &any) { return has_value (any) ? std::any_cast<T> (any) : fallback(); }
};
 
class CustomDataContainer {
  struct CustomDataEntry : std::any { VirtualBase *key = nullptr; };
  using CustomDataS = std::vector<CustomDataEntry>;
  std::unique_ptr<CustomDataS> custom_data_;
  static_assert (sizeof (custom_data_) == sizeof (void*));
  CustomDataEntry& custom_data_entry (VirtualBase *key);
  std::any&        custom_data_get   (VirtualBase *key) const;
  bool             custom_data_del   (VirtualBase *key);
protected:
  /*dtor*/       ~CustomDataContainer ();
  void            custom_data_destroy ();
public:
  template<class T> void set_custom_data  (CustomDataKey<T> *key, T data)
  { std::any a (data); custom_data_entry (key).swap (a); }
  template<class T> T    get_custom_data  (CustomDataKey<T> *key) const
  { return key->extract (custom_data_get (key)); }
  template<class T> bool has_custom_data  (CustomDataKey<T> *key) const
  { return key->has_value (custom_data_get (key)); }
  template<class T> bool del_custom_data  (CustomDataKey<T> *key)
  { return custom_data_del (key); }
};
 
// == Bit Manipulations ==
constexpr uint16_t uint16_swap_le_be (uint16_t v);
 
constexpr uint32_t uint32_swap_le_be (uint32_t v);
 
constexpr uint64_t uint64_swap_le_be (uint64_t v);
 
// == Implementation Details ==
extern inline constexpr uint16_t
uint16_swap_le_be (uint16_t v)
{
  return (v >> 8) | (v << 8);
}
 
extern inline constexpr uint32_t
uint32_swap_le_be (uint32_t v)
{
  return __builtin_bswap32 (v);
  return ( ((v & 0x000000ffU) << 24) |
           ((v & 0x0000ff00U) <<  8) |
           ((v & 0x00ff0000U) >>  8) |
           ((v & 0xff000000U) >> 24) );
}
 
extern inline constexpr uint64_t
uint64_swap_le_be (uint64_t v)
{
  return __builtin_bswap64 (v);
  return ( ((v & 0x00000000000000ffUL) << 56) |
           ((v & 0x000000000000ff00UL) << 40) |
           ((v & 0x0000000000ff0000UL) << 24) |
           ((v & 0x00000000ff000000UL) <<  8) |
           ((v & 0x000000ff00000000UL) >>  8) |
           ((v & 0x0000ff0000000000UL) >> 24) |
           ((v & 0x00ff000000000000UL) >> 40) |
           ((v & 0xff00000000000000UL) >> 56) );
}
 
template<class A0, class... Ar> const char*
ase_gettext (const char *format, const A0 &a0, const Ar &...restargs)
{
  return ase_gettext (string_format (format, a0, restargs...));
}
 
namespace Aux {
 
template<typename T>
using callable_reserve_int = decltype (std::declval<T&>().reserve (int (0)));
template<typename T>
using callable_minus = decltype (std::declval<T>() - std::declval<T>());
 
template<class Container, class Iteratable> Container
container_copy (const Iteratable &source)
{
  Container c;
  const auto b = std::begin (source), e = std::end (source);
  if constexpr (std::experimental::is_detected<callable_reserve_int, Container>::value &&
                std::experimental::is_detected<callable_minus, decltype (b)>::value) {
      c.reserve (e - b);
    }
  std::copy (b, e, std::back_inserter (c));
  return c;
}
 
// == Binary Lookups ==
template<typename RandIter, class Cmp, typename Arg, int case_lookup_or_sibling_or_insertion>
extern inline std::pair<RandIter,bool>
binary_lookup_fuzzy (RandIter begin, RandIter end, Cmp cmp_elements, const Arg &arg)
{
  RandIter current = end;
  size_t n_elements = end - begin, offs = 0;
  const bool want_lookup = case_lookup_or_sibling_or_insertion == 0;
  // const bool want_sibling = case_lookup_or_sibling_or_insertion == 1;
  const bool want_insertion_pos = case_lookup_or_sibling_or_insertion > 1;
  ssize_t cmp = 0;
  while (offs < n_elements)
    {
      size_t i = (offs + n_elements) >> 1;
      current = begin + i;
      cmp = cmp_elements (arg, *current);
      if (cmp == 0)
        return want_insertion_pos ? std::make_pair (current, true) : std::make_pair (current, /*ignored*/ false);
      else if (cmp < 0)
        n_elements = i;
      else /* (cmp > 0) */
        offs = i + 1;
    }
  /* check is last mismatch, cmp > 0 indicates greater key */
  return (want_lookup
          ? std::make_pair (end, /*ignored*/ false)
          : (want_insertion_pos && cmp > 0)
          ? std::make_pair (current + 1, false)
          : std::make_pair (current, false));
}
 
template<typename RandIter, class Cmp, typename Arg>
extern inline std::pair<RandIter,bool>
binary_lookup_insertion_pos (RandIter begin, RandIter end, Cmp cmp_elements, const Arg &arg)
{
  return binary_lookup_fuzzy<RandIter,Cmp,Arg,2> (begin, end, cmp_elements, arg);
}
 
template<typename RandIter, class Cmp, typename Arg>
extern inline RandIter
binary_lookup_sibling (RandIter begin, RandIter end, Cmp cmp_elements, const Arg &arg)
{
  return binary_lookup_fuzzy<RandIter,Cmp,Arg,1> (begin, end, cmp_elements, arg).first;
}
 
template<typename RandIter, class Cmp, typename Arg>
extern inline RandIter
binary_lookup (RandIter begin, RandIter end, Cmp cmp_elements, const Arg &arg)
{
  /* return end or exact match */
  return binary_lookup_fuzzy<RandIter,Cmp,Arg,0> (begin, end, cmp_elements, arg).first;
}
 
template<typename Value> static inline int
compare_lesser (const Value &v1, const Value &v2)
{
  return -(v1 < v2) | (v2 < v1);
}
 
template<typename Value> static inline int
compare_greater (const Value &v1, const Value &v2)
{
  return (v1 < v2) | -(v2 < v1);
}
 
// == Vector Utils ==
 
template<class C> inline size_t
erase_first (C &container, const std::function<bool (typename C::value_type const &value)> &pred)
{
  for (auto iter = container.begin(); iter != container.end(); iter++)
    if (pred (*iter))
      {
        container.erase (iter);
        return 1;
      }
  return 0;
}
 
template<class C> inline size_t
erase_all (C &container, const std::function<bool (typename C::value_type const &value)> &pred)
{
  size_t c = 0;
  for (auto iter = container.begin(); iter != container.end(); )
    if (pred (*iter))
      {
        iter = container.erase (iter);
        c++;
      }
    else
      iter++;
  return c;
}
 
template<typename C> inline bool
contains (const C &container, const std::function<bool (typename C::value_type const &value)> &pred)
{
  for (auto iter = container.begin(); iter != container.end(); iter++)
    if (pred (*iter))
      return true;
  return false;
}
 
template<class T, class Compare> inline typename std::vector<T>::iterator
insert_sorted (std::vector<T> &vec, const T &value, Compare compare)
{
  static_assert (std::is_signed<decltype (std::declval<Compare>() (std::declval<T>(), std::declval<T>()))>::value, "REQUIRE: int Compare (const&, const&);");
  auto insmatch = binary_lookup_insertion_pos (vec.begin(), vec.end(), compare, value);
  auto it = insmatch.first;
  return vec.insert (it, value);
}
 
template<class IterableContainer> ssize_t
index_of (const IterableContainer &c, const std::function<bool(const typename IterableContainer::value_type &e)> &match)
{
  ssize_t index = 0;
  for (auto it = std::begin (c); it != std::end (c); ++index, ++it)
    if (match (*it))
      return index;
  return -1;
}
 
} // Aux
 
} // Ase
 
#endif // __ASE_UTILS_HH__