sstream.cc

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_RWSTD_NAMESPACE (std) {
 
 
template<class _CharT, class _Traits, class _Allocator>
basic_stringbuf<_CharT, _Traits, _Allocator>::
basic_stringbuf (const _C_string_type& __str, ios_base::openmode __mode)
    : basic_streambuf<_CharT, _Traits>(__mode)
{
    str (__str);
}
 
 
// extension
template<class _CharT, class _Traits, class _Allocator>
basic_stringbuf<_CharT, _Traits, _Allocator>::
basic_stringbuf (const char_type *__s, ios_base::openmode __mode)
    : basic_streambuf<_CharT, _Traits>(__mode)
{
    _RWSTD_ASSERT (0 != __s);
 
    str (__s, traits_type::length (__s));
}
 
 
template <class _CharT, class _Traits, class _Allocator>
/* virtual */
basic_stringbuf<_CharT, _Traits, _Allocator>::
~basic_stringbuf ()
{
    typedef _RWSTD_ALLOC_TYPE (allocator_type, char_type) _ValueAlloc;
 
    if (this->_C_own_buf ())
        _ValueAlloc ().deallocate (this->_C_buffer, this->_C_bufsize);
}
 
 
// extension
template<class _CharT, class _Traits, class _Allocator>
void
basic_stringbuf<_CharT, _Traits, _Allocator>::
str (const char_type *__s, _RWSTD_SIZE_T __slen)
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    typedef _RWSTD_ALLOC_TYPE (allocator_type, char_type) _ValueAlloc;
 
    typedef _RWSTD_STREAMSIZE _Streamsize;
 
    // compute the lenth if not specified
    if (_RWSTD_SIZE_MAX == __slen)
        __slen = traits_type::length (__s);
 
    _ValueAlloc __alloc;
 
    // new buffer and size
    char_type        *__buf;
    _RWSTD_SIZE_T     __bufsize = __slen;
    // saved offset of pptr 
    _RWSTD_STREAMSIZE __off = -1;
 
    if (__s == this->_C_buffer) {
        // special case: str(_C_buffer, _C_bufsize + N) called
        // to increase the capacity of buffer
 
        _C_catchup (this->eback ());
 
        // set `slen' to the number of initialized characters
        // in the buffer
        __slen = this->egptr () - this->pbase ();
        // save the offset of pptr
        __off = this->pptr () - this->pbase ();
    }
 
    if (this->_C_bufsize < __bufsize) {
        // requested capacity is greater than the current capacity
        // allocate a new buffer of sufficient size
        const _RWSTD_STREAMSIZE __ratio =
            _RWSTD_STREAMSIZE (  (_RWSTD_NEW_CAPACITY_RATIO << 10)
                               / _RWSTD_RATIO_DIVIDER);
 
        const _RWSTD_SIZE_T __cap =
            this->_C_bufsize ?
              (this->_C_bufsize >> 10) * __ratio
            + (((this->_C_bufsize & 0x3ff) * __ratio) >> 10)
            : _RWSTD_MINIMUM_STRINGBUF_CAPACITY;
 
        __bufsize = __cap < __bufsize ? __bufsize : __cap;
 
        if (__s != this->_C_buffer && this->_C_own_buf ()) {
            // deallocate the existing buffer here only if the string
            // is not the same as the buffer itself; otherwise, copy
            // it to the newly allocated buffer first and deallocate
            // it later
            __alloc.deallocate (this->_C_buffer, this->_C_bufsize);
            this->_C_buffer = 0;
        }
 
        __buf = __alloc.allocate (__bufsize);
    }
    else if (0 < __bufsize) {
        // requested capacity is the same or less than the current one
        __buf     = this->_C_buffer;
        __bufsize = this->_C_bufsize;
    }
    else {
        // zero size and capacity, deallocate and reset all pointers
        __buf     = 0;
        __bufsize = 0;
 
        _RWSTD_ASSERT (0 == __slen);
    }
 
    // compute the "high mark" (see lwg issue 432)
    char_type* const __egptr = __buf + __slen;
 
    if (__s != __buf) {
        // copy the provided string to buffer
        traits_type::copy (__buf, __s, __slen);
 
        if (this->_C_buffer != __buf) {
            if (this->_C_buffer && this->_C_own_buf ())
                __alloc.deallocate (this->_C_buffer, this->_C_bufsize);
 
            // take ownership of the allocated buffer
            this->_C_own_buf (true);
 
            this->_C_buffer  = __buf;
            this->_C_bufsize = __bufsize;
        }
    }
 
    if (this->_C_is_in ())
        this->setg (this->_C_buffer, this->_C_buffer, __egptr);
    else {
        // when not in in mode set all get pointers to the same
        // value and use egptr() as the "high mark" (see lwg
        // issue 432)
        this->setg (__egptr, __egptr, __egptr);
    }
 
    if (this->_C_is_out ()) {
        this->setp (this->_C_buffer, this->_C_buffer + this->_C_bufsize);
 
        if (0 <= __off) {
            // restore the pptr
            this->pbump (__off);
        }
        else if (   this->_C_state & ios_base::in
                 || this->_C_state & (ios_base::app | ios_base::ate)) {
            // in input or append/ate modes seek to end
            // (see also lwg issue 562 for clarification)
            this->pbump (__slen);
        }
    }
 
    _RWSTD_ASSERT (this->_C_is_valid ());
}
 
 
template <class _CharT, class _Traits, class _Allocator>
streamsize
basic_stringbuf<_CharT, _Traits, _Allocator>::
xsputn (const char_type* __s, streamsize __n)
{
    _RWSTD_ASSERT (0 != __s || 0 == __n);
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    if (__n <= 0 || !this->_C_is_out ())
        return 0;
 
    if (this->epptr () - this->pptr () < __n) {
 
        // compute the total amount of space necessary
        const _RWSTD_SIZE_T __bufsize =
            __n + (this->pptr () - this->pbase ());
 
        _RWSTD_PTRDIFF_T __off = -1;
 
        if (this->pbase () <= __s && this->pptr () > __s) {
            // __s is a part of the buffer
            _RWSTD_ASSERT (this->epptr () >= __s + __n);
            // save the offset from pbase()
            __off = this->pbase () - __s;
        }
 
        // grow the buffer if necessary to accommodate the whole
        // string plus the contents of the buffer up to pptr()
        str (this->_C_buffer, __bufsize);
 
        _RWSTD_ASSERT (__n <= this->epptr () - this->pptr ());
 
        if (0 <= __off) {
            // correct __s after the buffer reallocation
            __s = this->pbase () + __off;
        }
    }
 
    // copy the whole string
    traits_type::copy (this->pptr (), __s, __n);
 
    this->pbump (__n);
 
    _C_catchup (this->eback ());
 
    return __n;
}
 
 
template <class _CharT, class _Traits, class _Allocator>
/* virtual */ streamsize
basic_stringbuf<_CharT, _Traits, _Allocator>::
showmanyc ()
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    // get egptr() caught up with pptr()
    _C_catchup (this->eback ());
 
    return streamsize (this->egptr () - this->gptr ());
}
 
 
template <class _CharT, class _Traits, class _Allocator>
/* virtual */ typename basic_stringbuf<_CharT, _Traits, _Allocator>::int_type
basic_stringbuf<_CharT, _Traits, _Allocator>::
underflow ()
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    if (this->gptr () < this->egptr ()) {
 
        _RWSTD_ASSERT (0 != this->gptr ());
 
        return traits_type::to_int_type (*this->gptr ());
    }
    else if (this->gptr () < this->pptr ()) {
 
        // get egptr() caught up with pptr()
        _C_catchup (this->eback ());
 
        if (this->gptr () < this->egptr ())
            return traits_type::to_int_type (*this->gptr ());
    }
 
    return traits_type::eof ();
}
 
 
template<class _CharT, class _Traits, class _Allocator>
typename basic_stringbuf<_CharT, _Traits, _Allocator>::int_type
basic_stringbuf<_CharT, _Traits, _Allocator>::
overflow (int_type __c)
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    // 27.7.1.3, p5, bullet 2 of C++ '03: when (c == eof)
    // indicate success even when not in out mode
    if (this->_C_is_eof (__c))
        return traits_type::not_eof (__c);
 
    if (!this->_C_is_out ())
        return traits_type::eof ();
 
    char_type* const __bufend = this->_C_buffer + this->_C_bufsize;
 
    if (this->pptr () == this->epptr ()) {
        // reallocate buffer
        str (this->_C_buffer, this->_C_bufsize + 1);
    }
    else if (this->epptr () < __bufend) {
        // bump up epptr() keeping pbase() and pptr() unchanged
 
        const _RWSTD_STREAMSIZE __off = this->pptr () - this->pbase ();
        this->setp (this->pbase (), __bufend);
        this->pbump (__off);
    }
 
    const int_type __retval = this->sputc (traits_type::to_char_type (__c));
 
    // get egptr() caught up with the value of pptr() after the call
    _C_catchup (this->_C_buffer);
 
    return __retval;
}
 
 
template<class _CharT, class _Traits, class _Allocator>
/* virtual */ typename basic_stringbuf<_CharT, _Traits, _Allocator>::int_type
basic_stringbuf<_CharT, _Traits, _Allocator>::
pbackfail (int_type __c)
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    if (!this->_C_putback_avail ())
        return traits_type::eof ();
 
    int_type __retval;
 
    const char_type __ch = traits_type::to_char_type (__c);
 
    if (traits_type::eq (__ch, *(this->gptr () - 1)) || this->_C_is_eof (__c)) {
        // "put back" original value
        this->gbump (-1);
        __retval = traits_type::not_eof (__c);
    }
    else if (this->_C_is_out ()) {
        // overwrite existing value with new value
        this->gbump (-1);
        traits_type::assign (*this->gptr (), __ch);
        __retval = __c;
    }
    else
        __retval = traits_type::eof ();
 
    return __retval;
}
 
 
template<class _CharT, class _Traits, class _Allocator>
/* virtual */ basic_streambuf<_CharT, _Traits>*
basic_stringbuf<_CharT, _Traits, _Allocator>::
setbuf (char_type* __buf, _RWSTD_STREAMSIZE __n)
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    if (!__buf && !__n)   // 27.7.1.3, p16
        return this;
 
    const _RWSTD_STREAMSIZE __slen = (this->egptr () < this->pptr () ?
        this->pptr () : this->egptr ()) - this->pbase ();
 
    if (__n < __slen || !this->_C_is_out())
        return 0;   // failure
 
    // compute the gptr and pptr offsets so the pointers can be restored
    const _RWSTD_STREAMSIZE __goff = this->gptr () - this->eback ();
    const _RWSTD_STREAMSIZE __poff = this->pptr () - this->pbase ();
 
    const bool __own_old_buf = this->_C_own_buf ();
 
    typedef _RWSTD_ALLOC_TYPE (allocator_type, char_type) _ValueAlloc;
 
    if (0 == __buf) {
        // allocate a new buffer of the specified size
        __buf = _ValueAlloc ().allocate (__n);
        this->_C_own_buf (true);
    }
    else
        this->_C_own_buf (false);
 
    // copy the contents of the existing buffer to the new one
    traits_type::copy (__buf, this->_C_buffer, __slen);
 
    if (__own_old_buf)
        _ValueAlloc ().deallocate (this->_C_buffer, this->_C_bufsize);
 
    this->_C_buffer  = __buf;
    this->_C_bufsize = __n;
 
    // reset the output and input sequences within the new buffer
    this->setp (this->_C_buffer, this->_C_buffer + this->_C_bufsize);
    this->pbump (__poff);   // ... and restore it
 
    char_type* const __egptr = this->_C_buffer + __slen;
 
    if (this->_C_is_in ())
        this->setg (this->_C_buffer, this->_C_buffer + __goff, __egptr);
    else {
        // use egptr as the "high mark" (see lwg issue 432)
        this->setg (__egptr, __egptr, __egptr);
    }
 
    return this;
}
 
 
template<class _CharT, class _Traits, class _Allocator>
/* virtual */ typename basic_stringbuf<_CharT, _Traits, _Allocator>::pos_type
basic_stringbuf<_CharT, _Traits, _Allocator>::
seekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __which)
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    // should implicitly hold as long as ios::seekdir is an enum
    _RWSTD_ASSERT (   ios_base::beg == __way
                   || ios_base::cur == __way
                   || ios_base::end == __way);
 
    _RWSTD_STREAMSIZE __newoff = -1;
 
    // get egptr() caught up with pptr()
    _C_catchup (this->eback ());
 
    if (__which & ios_base::in) {
 
        // LWG issue 453: the operation fails if either gptr() or pptr()
        // is a null pointer and the new offset newoff is nonzero
        if (!this->_C_is_in () || __off && !this->gptr ())
            return pos_type (off_type (-1));
 
        // do the checks for in|out mode here
        if (   __which & ios_base::out
            && (ios_base::cur == __way || !this->_C_is_out ()))
            return pos_type (off_type (-1));
 
        switch (__way) {
        case ios_base::beg: __newoff = 0; break;
        case ios_base::cur: __newoff = this->gptr () - this->eback (); break;
        case ios_base::end: __newoff = this->egptr () - this->eback (); break;
        }
 
        __newoff += __off;
 
        if (__newoff < 0 || this->egptr () - this->eback () < __newoff)
            return pos_type (off_type (-1));
 
        this->setg (this->eback (), this->eback () + __newoff, this->egptr ());
    }
 
    if (__which & ios_base::out) {
 
        // LWG issue 453: the operation fails if either gptr() or pptr()
        // is a null pointer and the new offset newoff is nonzero
        if (!this->_C_is_out () || __off && !this->pptr ())
            return pos_type (off_type (-1));
 
        // egptr() is used as the "high mark" even when not in "in" mode
        _RWSTD_ASSERT (0 == this->pbase () || 0 != this->egptr ());
 
        // compute the number of initialized characters in the buffer
        // (see LWG issue 432)
        const _RWSTD_STREAMSIZE __high = this->egptr () - this->pbase ();
        const _RWSTD_STREAMSIZE __cur  = this->pptr () - this->pbase ();
 
        switch (__way) {
        case ios_base::beg: __newoff = 0; break;
        case ios_base::cur: __newoff = __cur; break;
        case ios_base::end: __newoff = __high; break;
        }
 
        __newoff += __off;
 
        if (__newoff < 0 || __high < __newoff)
            return pos_type (off_type (-1));
 
        // bump pptr up (or down) to the new position
        this->pbump (__newoff - __cur);
    }
 
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    return __newoff < 0 ? pos_type (off_type (-1)) : pos_type (__newoff);
}
 
 
template<class _CharT, class _Traits, class _Allocator>
/* virtual */ typename basic_stringbuf<_CharT, _Traits, _Allocator>::pos_type
basic_stringbuf<_CharT, _Traits, _Allocator>::
seekpos (pos_type __pos, ios_base::openmode __which)
{
    _RWSTD_ASSERT (this->_C_is_valid ());
 
    // typedef helps HP aCC 3.27
    typedef basic_stringbuf _StringBuf;
 
    return pos_type (_StringBuf::seekoff (__pos, ios_base::beg, __which));
}
 
 
}   // namespace std