bvector.h

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C头文件 代码 · 共 420 行

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 */

// vector<bool> is replaced by bit_vector at present because bool is not
// implemented.  

#ifndef BVECTOR_H
#define BVECTOR_H

#include <function.h>
#include <algobase.h>
#include <iterator.h>
#include <bool.h>

#ifndef Allocator
#define Allocator allocator
#include <defalloc.h>
#endif

#define __WORD_BIT (int(CHAR_BIT*sizeof(unsigned int)))

class bit_vector {
public:
    typedef Allocator<unsigned int> vector_allocator;
    typedef bool value_type;
    typedef vector_allocator::size_type size_type;
    typedef vector_allocator::difference_type difference_type; 

    class iterator;
    class const_iterator;

    class reference {
    friend class iterator;
    friend class const_iterator;
    protected:
        unsigned int* p;
        unsigned int mask;
        reference(unsigned int* x, unsigned int y) : p(x), mask(y) {}
    public:
        reference() : p(0), mask(0) {}
        operator bool() const { return !(!(*p & mask)); }
        reference& operator=(bool x) {
            if (x)      
                *p |= mask;
            else 
                *p &= ~mask;
            return *this;
        }
        reference& operator=(const reference& x) { return *this = bool(x); }
        bool operator==(const reference& x) const {
            return bool(*this) == bool(x);
        }
        bool operator<(const reference& x) const {
            return bool(*this) < bool(x);
        }
        void flip() { *p ^= mask; }
    };
    typedef bool const_reference;
    class iterator : public random_access_iterator<bool, difference_type> {
    friend class bit_vector;
    friend class const_iterator;
    protected:
        unsigned int* p;
        unsigned int offset;
        void bump_up() {
            if (offset++ == __WORD_BIT - 1) {
                offset = 0;
                ++p;
            }
        }
    void bump_down() {
        if (offset-- == 0) {
            offset = __WORD_BIT - 1;
            --p;
        }
    }
    public:
        iterator() : p(0), offset(0) {}
        iterator(unsigned int* x, unsigned int y) : p(x), offset(y) {}
        reference operator*() const { return reference(p, 1U << offset); }
        iterator& operator++() {
            bump_up();
            return *this;
        }
        iterator operator++(int) {
            iterator tmp = *this;
            bump_up();
            return tmp;
        }
        iterator& operator--() {
            bump_down();
            return *this;
        }
        iterator operator--(int) {
            iterator tmp = *this;
            bump_down();
            return tmp;
        }
        iterator& operator+=(difference_type i) {
            difference_type n = i + offset;
            p += n / __WORD_BIT;
            n = n % __WORD_BIT;
            if (n < 0) {
                offset = n + __WORD_BIT;
                --p;
            } else
                offset = n;
            return *this;
        }
        iterator& operator-=(difference_type i) {
            *this += -i;
            return *this;
        }
        iterator operator+(difference_type i) const {
            iterator tmp = *this;
            return tmp += i;
        }
        iterator operator-(difference_type i) const {
            iterator tmp = *this;
            return tmp -= i;
        }
        difference_type operator-(iterator x) const {
            return __WORD_BIT * (p - x.p) + offset - x.offset;
        }
        reference operator[](difference_type i) { return *(*this + i); }
        bool operator==(const iterator& x) const {
            return p == x.p && offset == x.offset;
        }
        bool operator<(iterator x) const {
            return p < x.p || (p == x.p && offset < x.offset);
        }
    };

    class const_iterator 
        : public random_access_iterator<bool, difference_type> {
    friend class bit_vector;
    protected:
        unsigned int* p;
        unsigned int offset;
        void bump_up() {
            if (offset++ == __WORD_BIT - 1) {
                offset = 0;
                ++p;
            }
        }
    void bump_down() {
        if (offset-- == 0) {
            offset = __WORD_BIT - 1;
            --p;
        }
    }
    public:
        const_iterator() : p(0), offset(0) {}
        const_iterator(unsigned int* x, unsigned int y) : p(x), offset(y) {}
        const_iterator(const iterator& x) : p(x.p), offset(x.offset) {}
        const_reference operator*() const {
            return reference(p, 1U << offset);
        }
        const_iterator& operator++() {
            bump_up();
            return *this;
        }
        const_iterator operator++(int) {
            const_iterator tmp = *this;
            bump_up();
            return tmp;
        }
        const_iterator& operator--() {
            bump_down();
            return *this;
        }
        const_iterator operator--(int) {
            const_iterator tmp = *this;
            bump_down();
            return tmp;
        }
        const_iterator& operator+=(difference_type i) {
            difference_type n = i + offset;
            p += n / __WORD_BIT;
            n = n % __WORD_BIT;
            if (n < 0) {
                offset = n + __WORD_BIT;
                --p;
            } else
                offset = n;
            return *this;
        }
        const_iterator& operator-=(difference_type i) {
            *this += -i;
            return *this;
        }
        const_iterator operator+(difference_type i) const {
            const_iterator tmp = *this;
            return tmp += i;
        }
        const_iterator operator-(difference_type i) const {
            const_iterator tmp = *this;
            return tmp -= i;
        }
        difference_type operator-(const_iterator x) const {
            return __WORD_BIT * (p - x.p) + offset - x.offset;
        }
        const_reference operator[](difference_type i) { 
            return *(*this + i); 
        }
        bool operator==(const const_iterator& x) const {
            return p == x.p && offset == x.offset;
        }
        bool operator<(const_iterator x) const {
            return p < x.p || (p == x.p && offset < x.offset);
        }
    };

    typedef reverse_iterator<const_iterator, value_type, const_reference, 
                             difference_type> const_reverse_iterator;
    typedef reverse_iterator<iterator, value_type, reference, difference_type>
        reverse_iterator;

protected:
    static Allocator<unsigned int> static_allocator;
    iterator start;
    iterator finish;
    unsigned int* end_of_storage;
    unsigned int* bit_alloc(size_type n) {
        return static_allocator.allocate((n + __WORD_BIT - 1)/__WORD_BIT);
    }
    void initialize(size_type n) {
        unsigned int* q = bit_alloc(n);
        end_of_storage = q + (n + __WORD_BIT - 1)/__WORD_BIT;
        start = iterator(q, 0);
        finish = start + n;
    }
    void insert_aux(iterator position, bool x);
    typedef bit_vector self;
public:
    iterator begin() { return start; }
    const_iterator begin() const { return start; }
    iterator end() { return finish; }
    const_iterator end() const { return finish; }

    reverse_iterator rbegin() { return reverse_iterator(end()); }
    const_reverse_iterator rbegin() const { 
        return const_reverse_iterator(end()); 
    }
    reverse_iterator rend() { return reverse_iterator(begin()); }
    const_reverse_iterator rend() const { 
        return const_reverse_iterator(begin()); 
    }

    size_type size() const { return size_type(end() - begin()); }
    size_type max_size() const { return static_allocator.max_size(); }
    size_type capacity() const {
        return size_type(const_iterator(end_of_storage, 0) - begin());
    }
    bool empty() const { return begin() == end(); }
    reference operator[](size_type n) { return *(begin() + n); }
    const_reference operator[](size_type n) const { return *(begin() + n); }
    bit_vector() : start(iterator()), finish(iterator()), end_of_storage(0) {}
    bit_vector(size_type n, bool value = bool()) {
        initialize(n);
        fill(start.p, end_of_storage, value ? ~0 : 0);
    }
    bit_vector(const self& x) {
        initialize(x.size());
        copy(x.begin(), x.end(), start);
    }
    bit_vector(const_iterator first, const_iterator last) {
        size_type n = 0;
        distance(first, last, n);
        initialize(n);
        copy(first, last, start);
    }
    ~bit_vector() { static_allocator.deallocate(start.p); }
    self& operator=(const self& x) {
        if (&x == this) return *this;
        if (x.size() > capacity()) {
            static_allocator.deallocate(start.p); 
            initialize(x.size());
        }
        copy(x.begin(), x.end(), begin());
        finish = begin() + x.size();
        return *this;
    }
    void reserve(size_type n) {
        if (capacity() < n) {
            unsigned int* q = bit_alloc(n);
            finish = copy(begin(), end(), iterator(q, 0));
            static_allocator.deallocate(start.p);
            start = iterator(q, 0);
            end_of_storage = q + (n + __WORD_BIT - 1)/__WORD_BIT;
        }
    }
    reference front() { return *begin(); }
    const_reference front() const { return *begin(); }
    reference back() { return *(end() - 1); }
    const_reference back() const { return *(end() - 1); }
    void push_back(bool x) {
        if (finish.p != end_of_storage)
            *finish++ = x;
        else
            insert_aux(end(), x);
    }
    void swap(bit_vector& x) {
        ::swap(start, x.start);
        ::swap(finish, x.finish);
        ::swap(end_of_storage, x.end_of_storage);
    }
    iterator insert(iterator position, bool x) {
        size_type n = position - begin();
        if (finish.p != end_of_storage && position == end())
            *finish++ = x;
        else
            insert_aux(position, x);
        return begin() + n;
    }
    void insert(iterator position, const_iterator first, 
                const_iterator last);
    void insert(iterator position, size_type n, bool x);
    void pop_back() { --finish; }
    void erase(iterator position) {
        if (position + 1 != end())
            copy(position + 1, end(), position);
        --finish;
    }
    void erase(iterator first, iterator last) {
        finish = copy(last, end(), first);
    }
};

Allocator<unsigned int> bit_vector::static_allocator;

inline bool operator==(const bit_vector& x, const bit_vector& y) {
    return x.size() == y.size() && equal(x.begin(), x.end(), y.begin());
}

inline bool operator<(const bit_vector& x, const bit_vector& y) {
    return lexicographical_compare(x.begin(), x.end(), y.begin(), y.end());
}

void swap(bit_vector::reference x, bit_vector::reference y) {
    bool tmp = x;
    x = y;
    y = tmp;
}

void bit_vector::insert_aux(iterator position, bool x) {
    if (finish.p != end_of_storage) {
        copy_backward(position, finish - 1, finish);
        *position = x;
        ++finish;
    } else {
        size_type len = size() ? 2 * size() : __WORD_BIT;
        unsigned int* q = bit_alloc(len);
        iterator i = copy(begin(), position, iterator(q, 0));
        *i++ = x;
        finish = copy(position, end(), i);
        static_allocator.deallocate(start.p);
        end_of_storage = q + (len + __WORD_BIT - 1)/__WORD_BIT;
        start = iterator(q, 0);
    }
}

void bit_vector::insert(iterator position, size_type n, bool x) {
    if (n == 0) return;
    if (capacity() - size() >= n) {
        copy_backward(position, end(), finish + n);
        fill(position, position + n, x);
        finish += n;
    } else {
        size_type len = size() + max(size(), n);
        unsigned int* q = bit_alloc(len);
        iterator i = copy(begin(), position, iterator(q, 0));
        fill_n(i, n, x);
        finish = copy(position, end(), i + n);
        static_allocator.deallocate(start.p);
        end_of_storage = q + (n + __WORD_BIT - 1)/__WORD_BIT;
        start = iterator(q, 0);
    }
}

void bit_vector::insert(iterator position, const_iterator first, 
                        const_iterator last) {
    if (first == last) return;
    size_type n = 0;
    distance(first, last, n);
    if (capacity() - size() >= n) {
        copy_backward(position, end(), finish + n);
        copy(first, last, position);
        finish += n;
    } else {
        size_type len = size() + max(size(), n);
        unsigned int* q = bit_alloc(len);
        iterator i = copy(begin(), position, iterator(q, 0));
        i = copy(first, last, i);
        finish = copy(position, end(), i);
        static_allocator.deallocate(start.p);
        end_of_storage = q + (len + __WORD_BIT - 1)/__WORD_BIT;
        start = iterator(q, 0);
    }
}

#undef Allocator
#undef __WORD_BIT

#endif