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BUG#:7124
TITLE: HP-UX PA-RISC 11.00 - Nightly tests failing

DESCRIPTION: The Bugfix reduces the impact on memory usage introduced by the OrderedSet implementation. To do this data structures are made dynamically allocated(not static as before) and the minimal capacity of the used Buffer is reduced to 64 bytes.
The constructor of the Buffer class now allows to specify how large the minimum capacity of the Buffer shall be.

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#include <cstring>
#include "Buffer.h"
#include "Pegasus/Common/InternalException.h"

PEGASUS_NAMESPACE_BEGIN

//
// Note: _empty_rep is the only BufferRep object that may have a zero capacity.
// So "_rep->cap == 0" implies "_rep == _empty_rep". But some platforms produce
// more than one instance of _empty_rep (strangely). Therefore, it is safer to
// use the former test rather than the latter.
//
BufferRep Buffer::_empty_rep =
{
    0, /* size */
    0, /* cap (zero implies it is the _empty_rep) */
    {0} /* data[0] */
};

static Uint32 _next_pow_2(Uint32 x, Uint32 minCap)
{
    // Check for potential overflow in x.
    PEGASUS_CHECK_CAPACITY_OVERFLOW(x);

    if (x < minCap)
        return minCap;

    x--;
    x |= (x >> 1);
    x |= (x >> 2);
    x |= (x >> 4);
    x |= (x >> 8);
    x |= (x >> 16);
    x++;

    return x;
}

static inline BufferRep* _allocate(Uint32 cap, Uint32 minCap)
{
    if (cap < minCap)
        cap = minCap;

    // Allocate an extra byte for null-termination performed by getData().
    BufferRep* rep = (BufferRep*)malloc(sizeof(BufferRep) + cap + 1);

    if (!rep)
    {
        throw PEGASUS_STD(bad_alloc)();
    }
    rep->cap = cap;
    return rep;
}

static inline BufferRep* _reallocate(BufferRep* rep, Uint32 cap)
{
    // Allocate an extra byte for null-termination performed by getData().
    rep = (BufferRep*)realloc(rep, sizeof(BufferRep) + cap + 1);

    if (!rep)
    {
        throw PEGASUS_STD(bad_alloc)();
    }
    rep->cap = cap;
    return rep;
}

Buffer::Buffer(const Buffer& x)
{
    _rep = _allocate(x._rep->cap, x._minCap);
    memcpy(_rep->data, x._rep->data, x._rep->size);
    _rep->size = x._rep->size;
    _minCap=x._minCap;
}

Buffer::Buffer(const char* data, Uint32 size, Uint32 minCap): _minCap(minCap)
{
    _rep = _allocate(size, _minCap);
    _rep->size = size;
    memcpy(_rep->data, data, size);
}

Buffer& Buffer::operator=(const Buffer& x)
{
    if (&x != this)
    {
        if (x._rep->size > _rep->cap)
        {
            if (_rep->cap != 0)
                free(_rep);

            _rep = _allocate(x._rep->cap, x._minCap);
        }

        memcpy(_rep->data, x._rep->data, x._rep->size);
        _rep->size = x._rep->size;
        _minCap = x._minCap;
    }
    return *this;
}

void Buffer::_reserve_aux(Uint32 cap)
{
    if (_rep->cap == 0)
    {
        _rep = _allocate(cap, _minCap);
        _rep->size = 0;
    }
    else
        _rep = _reallocate(_rep, _next_pow_2(cap, _minCap));
}

void Buffer::_append_char_aux()
{
    if (_rep->cap == 0)
    {
        _rep = _allocate(_minCap, _minCap);
        _rep->size = 0;
    }
    else
    {
        // Check for potential overflow.
        PEGASUS_CHECK_CAPACITY_OVERFLOW(_rep->cap);
        _rep = _reallocate(_rep, _rep->cap ? (2 * _rep->cap) : _minCap);
    }
}

void Buffer::insert(Uint32 pos, const char* data, Uint32 size)
{
    if (pos > _rep->size)
        return;

    Uint32 cap = _rep->size + size;
    Uint32 rem = _rep->size - pos;

    if (cap > _rep->cap)
    {
        BufferRep* rep = _allocate(cap, _minCap);
        rep->size = cap;

        memcpy(rep->data, _rep->data, pos);
        memcpy(rep->data + pos, data, size);
        memcpy(rep->data + pos + size, _rep->data + pos, rem);

        if (_rep->cap != 0)
            free(_rep);

        _rep = rep;
    }
    else
    {
        memmove(_rep->data + pos + size, _rep->data + pos, rem);
        memcpy(_rep->data + pos, data, size);
        _rep->size += size;
    }
}

void Buffer::remove(Uint32 pos, Uint32 size)
{
    if (pos + size > _rep->size)
        return;

    Uint32 rem = _rep->size - (pos + size);

    if (rem)
        memmove(_rep->data + pos, _rep->data + pos + size, rem);

    _rep->size -= size;
}

PEGASUS_NAMESPACE_END