unity/crnlib/crn_vector.h

// File: crn_vector.h
// See Copyright Notice and license at the end of inc/crnlib.h
#pragma once

namespace crnlib {
struct elemental_vector {
  void* m_p;
  uint m_size;
  uint m_capacity;

  typedef void (*object_mover)(void* pDst, void* pSrc, uint num);

  bool increase_capacity(uint min_new_capacity, bool grow_hint, uint element_size, object_mover pRelocate, bool nofail);
};

template <typename T>
class vector : public helpers::rel_ops<vector<T> > {
 public:
  typedef T* iterator;
  typedef const T* const_iterator;
  typedef T value_type;
  typedef T& reference;
  typedef const T& const_reference;
  typedef T* pointer;
  typedef const T* const_pointer;

  inline vector()
      : m_p(NULL),
        m_size(0),
        m_capacity(0) {
  }

  inline vector(uint n, const T& init)
      : m_p(NULL),
        m_size(0),
        m_capacity(0) {
    increase_capacity(n, false);
    helpers::construct_array(m_p, n, init);
    m_size = n;
  }

  inline vector(const vector& other)
      : m_p(NULL),
        m_size(0),
        m_capacity(0) {
    increase_capacity(other.m_size, false);

    m_size = other.m_size;

    if (CRNLIB_IS_BITWISE_COPYABLE(T))
      memcpy(m_p, other.m_p, m_size * sizeof(T));
    else {
      T* pDst = m_p;
      const T* pSrc = other.m_p;
      for (uint i = m_size; i > 0; i--)
        helpers::construct(pDst++, *pSrc++);
    }
  }

  inline explicit vector(uint size)
      : m_p(NULL),
        m_size(0),
        m_capacity(0) {
    resize(size);
  }

  inline ~vector() {
    if (m_p) {
      scalar_type<T>::destruct_array(m_p, m_size);
      crnlib_free(m_p);
    }
  }

  inline vector& operator=(const vector& other) {
    if (this == &other)
      return *this;

    if (m_capacity >= other.m_size)
      resize(0);
    else {
      clear();
      increase_capacity(other.m_size, false);
    }

    if (CRNLIB_IS_BITWISE_COPYABLE(T))
      memcpy(m_p, other.m_p, other.m_size * sizeof(T));
    else {
      T* pDst = m_p;
      const T* pSrc = other.m_p;
      for (uint i = other.m_size; i > 0; i--)
        helpers::construct(pDst++, *pSrc++);
    }

    m_size = other.m_size;

    return *this;
  }

  inline const T* begin() const { return m_p; }
  T* begin() { return m_p; }

  inline const T* end() const { return m_p + m_size; }
  T* end() { return m_p + m_size; }

  inline bool empty() const { return !m_size; }
  inline uint size() const { return m_size; }
  inline uint size_in_bytes() const { return m_size * sizeof(T); }
  inline uint capacity() const { return m_capacity; }

  // operator[] will assert on out of range indices, but in final builds there is (and will never be) any range checking on this method.
  inline const T& operator[](uint i) const {
    CRNLIB_ASSERT(i < m_size);
    return m_p[i];
  }
  inline T& operator[](uint i) {
    CRNLIB_ASSERT(i < m_size);
    return m_p[i];
  }

  // at() always includes range checking, even in final builds, unlike operator [].
  // The first element is returned if the index is out of range.
  inline const T& at(uint i) const {
    CRNLIB_ASSERT(i < m_size);
    return (i >= m_size) ? m_p[0] : m_p[i];
  }
  inline T& at(uint i) {
    CRNLIB_ASSERT(i < m_size);
    return (i >= m_size) ? m_p[0] : m_p[i];
  }

  inline const T& front() const {
    CRNLIB_ASSERT(m_size);
    return m_p[0];
  }
  inline T& front() {
    CRNLIB_ASSERT(m_size);
    return m_p[0];
  }

  inline const T& back() const {
    CRNLIB_ASSERT(m_size);
    return m_p[m_size - 1];
  }
  inline T& back() {
    CRNLIB_ASSERT(m_size);
    return m_p[m_size - 1];
  }

  inline const T* get_ptr() const { return m_p; }
  inline T* get_ptr() { return m_p; }

  // clear() sets the container to empty, then frees the allocated block.
  inline void clear() {
    if (m_p) {
      scalar_type<T>::destruct_array(m_p, m_size);
      crnlib_free(m_p);
      m_p = NULL;
      m_size = 0;
      m_capacity = 0;
    }
  }

  inline void clear_no_destruction() {
    if (m_p) {
      crnlib_free(m_p);
      m_p = NULL;
      m_size = 0;
      m_capacity = 0;
    }
  }

  inline void reserve(uint new_capacity) {
    if (new_capacity > m_capacity)
      increase_capacity(new_capacity, false);
    else if (new_capacity < m_capacity) {
      // Must work around the lack of a "decrease_capacity()" method.
      // This case is rare enough in practice that it's probably not worth implementing an optimized in-place resize.
      vector tmp;
      tmp.increase_capacity(math::maximum(m_size, new_capacity), false);
      tmp = *this;
      swap(tmp);
    }
  }

  inline bool try_reserve(uint new_capacity) {
    return increase_capacity(new_capacity, true, true);
  }

  // resize(0) sets the container to empty, but does not free the allocated block.
  inline void resize(uint new_size, bool grow_hint = false) {
    if (m_size != new_size) {
      if (new_size < m_size)
        scalar_type<T>::destruct_array(m_p + new_size, m_size - new_size);
      else {
        if (new_size > m_capacity)
          increase_capacity(new_size, (new_size == (m_size + 1)) || grow_hint);

        scalar_type<T>::construct_array(m_p + m_size, new_size - m_size);
      }

      m_size = new_size;
    }
  }

  inline bool try_resize(uint new_size, bool grow_hint = false) {
    if (m_size != new_size) {
      if (new_size < m_size)
        scalar_type<T>::destruct_array(m_p + new_size, m_size - new_size);
      else {
        if (new_size > m_capacity) {
          if (!increase_capacity(new_size, (new_size == (m_size + 1)) || grow_hint, true))
            return false;
        }

        scalar_type<T>::construct_array(m_p + m_size, new_size - m_size);
      }

      m_size = new_size;
    }

    return true;
  }

  // If size >= capacity/2, reset() sets the container's size to 0 but doesn't free the allocated block (because the container may be similarly loaded in the future).
  // Otherwise it blows away the allocated block. See http://www.codercorner.com/blog/?p=494
  inline void reset() {
    if (m_size >= (m_capacity >> 1))
      resize(0);
    else
      clear();
  }

  inline T* enlarge(uint i) {
    uint cur_size = m_size;
    resize(cur_size + i, true);
    return get_ptr() + cur_size;
  }

  inline T* try_enlarge(uint i) {
    uint cur_size = m_size;
    if (!try_resize(cur_size + i, true))
      return NULL;
    return get_ptr() + cur_size;
  }

  inline void push_back(const T& obj) {
    CRNLIB_ASSERT(!m_p || (&obj < m_p) || (&obj >= (m_p + m_size)));

    if (m_size >= m_capacity)
      increase_capacity(m_size + 1, true);

    scalar_type<T>::construct(m_p + m_size, obj);
    m_size++;
  }

  inline bool try_push_back(const T& obj) {
    CRNLIB_ASSERT(!m_p || (&obj < m_p) || (&obj >= (m_p + m_size)));

    if (m_size >= m_capacity) {
      if (!increase_capacity(m_size + 1, true, true))
        return false;
    }

    scalar_type<T>::construct(m_p + m_size, obj);
    m_size++;

    return true;
  }

  inline void push_back_value(T obj) {
    if (m_size >= m_capacity)
      increase_capacity(m_size + 1, true);

    scalar_type<T>::construct(m_p + m_size, obj);
    m_size++;
  }

  inline void pop_back() {
    CRNLIB_ASSERT(m_size);

    if (m_size) {
      m_size--;
      scalar_type<T>::destruct(&m_p[m_size]);
    }
  }

  inline void insert(uint index, const T* p, uint n) {
    CRNLIB_ASSERT(index <= m_size);
    if (!n)
      return;

    const uint orig_size = m_size;
    resize(m_size + n, true);

    const uint num_to_move = orig_size - index;

    if (CRNLIB_IS_BITWISE_COPYABLE(T)) {
      // This overwrites the destination object bits, but bitwise copyable means we don't need to worry about destruction.
      memmove(m_p + index + n, m_p + index, sizeof(T) * num_to_move);
    } else {
      const T* pSrc = m_p + orig_size - 1;
      T* pDst = const_cast<T*>(pSrc) + n;

      for (uint i = 0; i < num_to_move; i++) {
        CRNLIB_ASSERT((pDst - m_p) < (int)m_size);
        *pDst-- = *pSrc--;
      }
    }

    T* pDst = m_p + index;

    if (CRNLIB_IS_BITWISE_COPYABLE(T)) {
      // This copies in the new bits, overwriting the existing objects, which is OK for copyable types that don't need destruction.
      memcpy(pDst, p, sizeof(T) * n);
    } else {
      for (uint i = 0; i < n; i++) {
        CRNLIB_ASSERT((pDst - m_p) < (int)m_size);
        *pDst++ = *p++;
      }
    }
  }

  // push_front() isn't going to be very fast - it's only here for usability.
  inline void push_front(const T& obj) {
    insert(0, &obj, 1);
  }

  vector& append(const vector& other) {
    if (other.m_size)
      insert(m_size, &other[0], other.m_size);
    return *this;
  }

  vector& append(const T* p, uint n) {
    if (n)
      insert(m_size, p, n);
    return *this;
  }

  inline void erase(uint start, uint n) {
    CRNLIB_ASSERT((start + n) <= m_size);
    if ((start + n) > m_size)
      return;

    if (!n)
      return;

    const uint num_to_move = m_size - (start + n);

    T* pDst = m_p + start;

    const T* pSrc = m_p + start + n;

    if (CRNLIB_IS_BITWISE_COPYABLE_OR_MOVABLE(T)) {
      // This test is overly cautious.
      if ((!CRNLIB_IS_BITWISE_COPYABLE(T)) || (CRNLIB_HAS_DESTRUCTOR(T))) {
        // Type has been marked explictly as bitwise movable, which means we can move them around but they may need to be destructed.
        // First destroy the erased objects.
        scalar_type<T>::destruct_array(pDst, n);
      }

      // Copy "down" the objects to preserve, filling in the empty slots.
      memmove(pDst, pSrc, num_to_move * sizeof(T));
    } else {
      // Type is not bitwise copyable or movable.
      // Move them down one at a time by using the equals operator, and destroying anything that's left over at the end.
      T* pDst_end = pDst + num_to_move;
      while (pDst != pDst_end)
        *pDst++ = *pSrc++;

      scalar_type<T>::destruct_array(pDst_end, n);
    }

    m_size -= n;
  }

  inline void erase(uint index) {
    erase(index, 1);
  }

  inline void erase(T* p) {
    CRNLIB_ASSERT((p >= m_p) && (p < (m_p + m_size)));
    erase(static_cast<uint>(p - m_p));
  }

  void erase_unordered(uint index) {
    CRNLIB_ASSERT(index < m_size);

    if ((index + 1) < m_size)
      (*this)[index] = back();

    pop_back();
  }

  inline bool operator==(const vector& rhs) const {
    if (m_size != rhs.m_size)
      return false;
    else if (m_size) {
      if (scalar_type<T>::cFlag)
        return memcmp(m_p, rhs.m_p, sizeof(T) * m_size) == 0;
      else {
        const T* pSrc = m_p;
        const T* pDst = rhs.m_p;
        for (uint i = m_size; i; i--)
          if (!(*pSrc++ == *pDst++))
            return false;
      }
    }

    return true;
  }

  inline bool operator<(const vector& rhs) const {
    const uint min_size = math::minimum(m_size, rhs.m_size);

    const T* pSrc = m_p;
    const T* pSrc_end = m_p + min_size;
    const T* pDst = rhs.m_p;

    while ((pSrc < pSrc_end) && (*pSrc == *pDst)) {
      pSrc++;
      pDst++;
    }

    if (pSrc < pSrc_end)
      return *pSrc < *pDst;

    return m_size < rhs.m_size;
  }

  inline void swap(vector& other) {
    utils::swap(m_p, other.m_p);
    utils::swap(m_size, other.m_size);
    utils::swap(m_capacity, other.m_capacity);
  }

  inline void sort() {
    std::sort(begin(), end());
  }

  inline void unique() {
    if (!empty()) {
      sort();

      resize(std::unique(begin(), end()) - begin());
    }
  }

  inline void reverse() {
    uint j = m_size >> 1;
    for (uint i = 0; i < j; i++)
      utils::swap(m_p[i], m_p[m_size - 1 - i]);
  }

  inline int find(const T& key) const {
    const T* p = m_p;
    const T* p_end = m_p + m_size;

    uint index = 0;

    while (p != p_end) {
      if (key == *p)
        return index;

      p++;
      index++;
    }

    return cInvalidIndex;
  }

  inline int find_sorted(const T& key) const {
    if (m_size) {
      // Uniform binary search - Knuth Algorithm 6.2.1 U, unrolled twice.
      int i = ((m_size + 1) >> 1) - 1;
      int m = m_size;

      for (;;) {
        CRNLIB_ASSERT_OPEN_RANGE(i, 0, (int)m_size);
        const T* pKey_i = m_p + i;
        int cmp = key < *pKey_i;
        if ((!cmp) && (key == *pKey_i))
          return i;
        m >>= 1;
        if (!m)
          break;
        cmp = -cmp;
        i += (((m + 1) >> 1) ^ cmp) - cmp;

        CRNLIB_ASSERT_OPEN_RANGE(i, 0, (int)m_size);
        pKey_i = m_p + i;
        cmp = key < *pKey_i;
        if ((!cmp) && (key == *pKey_i))
          return i;
        m >>= 1;
        if (!m)
          break;
        cmp = -cmp;
        i += (((m + 1) >> 1) ^ cmp) - cmp;
      }
    }

    return cInvalidIndex;
  }

  template <typename Q>
  inline int find_sorted(const T& key, Q less_than) const {
    if (m_size) {
      // Uniform binary search - Knuth Algorithm 6.2.1 U, unrolled twice.
      int i = ((m_size + 1) >> 1) - 1;
      int m = m_size;

      for (;;) {
        CRNLIB_ASSERT_OPEN_RANGE(i, 0, (int)m_size);
        const T* pKey_i = m_p + i;
        int cmp = less_than(key, *pKey_i);
        if ((!cmp) && (!less_than(*pKey_i, key)))
          return i;
        m >>= 1;
        if (!m)
          break;
        cmp = -cmp;
        i += (((m + 1) >> 1) ^ cmp) - cmp;

        CRNLIB_ASSERT_OPEN_RANGE(i, 0, (int)m_size);
        pKey_i = m_p + i;
        cmp = less_than(key, *pKey_i);
        if ((!cmp) && (!less_than(*pKey_i, key)))
          return i;
        m >>= 1;
        if (!m)
          break;
        cmp = -cmp;
        i += (((m + 1) >> 1) ^ cmp) - cmp;
      }
    }

    return cInvalidIndex;
  }

  inline uint count_occurences(const T& key) const {
    uint c = 0;

    const T* p = m_p;
    const T* p_end = m_p + m_size;

    while (p != p_end) {
      if (key == *p)
        c++;

      p++;
    }

    return c;
  }

  inline void set_all(const T& o) {
    if ((sizeof(T) == 1) && (scalar_type<T>::cFlag))
      memset(m_p, *reinterpret_cast<const uint8*>(&o), m_size);
    else {
      T* pDst = m_p;
      T* pDst_end = pDst + m_size;
      while (pDst != pDst_end)
        *pDst++ = o;
    }
  }

  // Caller assumes ownership of the heap block associated with the container. Container is cleared.
  inline void* assume_ownership() {
    T* p = m_p;
    m_p = NULL;
    m_size = 0;
    m_capacity = 0;
    return p;
  }

  // Caller is granting ownership of the indicated heap block.
  // Block must have size constructed elements, and have enough room for capacity elements.
  inline bool grant_ownership(T* p, uint size, uint capacity) {
    // To to prevent the caller from obviously shooting themselves in the foot.
    if (((p + capacity) > m_p) && (p < (m_p + m_capacity))) {
      // Can grant ownership of a block inside the container itself!
      CRNLIB_ASSERT(0);
      return false;
    }

    if (size > capacity) {
      CRNLIB_ASSERT(0);
      return false;
    }

    if (!p) {
      if (capacity) {
        CRNLIB_ASSERT(0);
        return false;
      }
    } else if (!capacity) {
      CRNLIB_ASSERT(0);
      return false;
    }

    clear();
    m_p = p;
    m_size = size;
    m_capacity = capacity;
    return true;
  }

 private:
  T* m_p;
  uint m_size;
  uint m_capacity;

  template <typename Q>
  struct is_vector {
    enum { cFlag = false };
  };
  template <typename Q>
  struct is_vector<vector<Q> > {
    enum { cFlag = true };
  };

  static void object_mover(void* pDst_void, void* pSrc_void, uint num) {
    T* pSrc = static_cast<T*>(pSrc_void);
    T* const pSrc_end = pSrc + num;
    T* pDst = static_cast<T*>(pDst_void);

    while (pSrc != pSrc_end) {
      // placement new
      new (static_cast<void*>(pDst)) T(*pSrc);
      pSrc->~T();
      ++pSrc;
      ++pDst;
    }
  }

  inline bool increase_capacity(uint min_new_capacity, bool grow_hint, bool nofail = false) {
    return reinterpret_cast<elemental_vector*>(this)->increase_capacity(
        min_new_capacity, grow_hint, sizeof(T),
        (CRNLIB_IS_BITWISE_COPYABLE_OR_MOVABLE(T) || (is_vector<T>::cFlag)) ? NULL : object_mover, nofail);
  }
};

typedef crnlib::vector<uint8> uint8_vec;

template <typename T>
struct bitwise_movable<vector<T> > {
  enum { cFlag = true };
};

extern void vector_test();

template <typename T>
inline void swap(vector<T>& a, vector<T>& b) {
  a.swap(b);
}

}  // namespace crnlib