//===------------------------ strstream.cpp -------------------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#include "strstream"

#include "algorithm"

#include "climits"

#include "cstring"

#include "cstdlib"

#include "__debug"

#include "__undef_macros"

_LIBCPP_BEGIN_NAMESPACE_STD

strstreambuf::strstreambuf(streamsize __alsize)

    : __strmode_(__dynamic),

      __alsize_(__alsize),

      __palloc_(nullptr),

      __pfree_(nullptr)

{

}

strstreambuf::strstreambuf(void* (*__palloc)(size_t), void (*__pfree)(void*))

    : __strmode_(__dynamic),

      __alsize_(__default_alsize),

      __palloc_(__palloc),

      __pfree_(__pfree)

{

}

void

strstreambuf::__init(char* __gnext, streamsize __n, char* __pbeg)

{

    if (__n == 0)

        __n = static_cast<streamsize>(strlen(__gnext));

    else if (__n < 0)

        __n = INT_MAX;

    if (__pbeg == nullptr)

        setg(__gnext, __gnext, __gnext + __n);

    else

    {

        setg(__gnext, __gnext, __pbeg);

        setp(__pbeg, __pbeg + __n);

    }

}

strstreambuf::strstreambuf(char* __gnext, streamsize __n, char* __pbeg)

    : __strmode_(),

      __alsize_(__default_alsize),

      __palloc_(nullptr),

      __pfree_(nullptr)

{

    __init(__gnext, __n, __pbeg);

}

strstreambuf::strstreambuf(const char* __gnext, streamsize __n)

    : __strmode_(__constant),

      __alsize_(__default_alsize),

      __palloc_(nullptr),

      __pfree_(nullptr)

{

    __init(const_cast<char *>(__gnext), __n, nullptr);

}

strstreambuf::strstreambuf(signed char* __gnext, streamsize __n, signed char* __pbeg)

    : __strmode_(),

      __alsize_(__default_alsize),

      __palloc_(nullptr),

      __pfree_(nullptr)

{

    __init(const_cast<char *>(reinterpret_cast<const char*>(__gnext)), __n, reinterpret_cast<char*>(__pbeg));

}

strstreambuf::strstreambuf(const signed char* __gnext, streamsize __n)

    : __strmode_(__constant),

      __alsize_(__default_alsize),

      __palloc_(nullptr),

      __pfree_(nullptr)

{

    __init(const_cast<char *>(reinterpret_cast<const char*>(__gnext)), __n, nullptr);

}

strstreambuf::strstreambuf(unsigned char* __gnext, streamsize __n, unsigned char* __pbeg)

    : __strmode_(),

      __alsize_(__default_alsize),

      __palloc_(nullptr),

      __pfree_(nullptr)

{

    __init(const_cast<char *>(reinterpret_cast<const char*>(__gnext)), __n, reinterpret_cast<char*>(__pbeg));

}

strstreambuf::strstreambuf(const unsigned char* __gnext, streamsize __n)

    : __strmode_(__constant),

      __alsize_(__default_alsize),

      __palloc_(nullptr),

      __pfree_(nullptr)

{

    __init(const_cast<char *>(reinterpret_cast<const char*>(__gnext)), __n, nullptr);

}

strstreambuf::~strstreambuf()

{

    if (eback() && (__strmode_ & __allocated) != 0 && (__strmode_ & __frozen) == 0)

    {

        if (__pfree_)

            __pfree_(eback());

        else

            delete [] eback();

    }

}

void

strstreambuf::swap(strstreambuf& __rhs)

{

    streambuf::swap(__rhs);

    _VSTD::swap(__strmode_, __rhs.__strmode_);

    _VSTD::swap(__alsize_, __rhs.__alsize_);

    _VSTD::swap(__palloc_, __rhs.__palloc_);

    _VSTD::swap(__pfree_, __rhs.__pfree_);

}

void

strstreambuf::freeze(bool __freezefl)

{

    if (__strmode_ & __dynamic)

    {

        if (__freezefl)

            __strmode_ |= __frozen;

        else

            __strmode_ &= ~__frozen;

    }

}

char*

strstreambuf::str()

{

    if (__strmode_ & __dynamic)

        __strmode_ |= __frozen;

    return eback();

}

int

strstreambuf::pcount() const

{

    return static_cast<int>(pptr() - pbase());

}

strstreambuf::int_type

strstreambuf::overflow(int_type __c)

{

    if (__c == EOF)

        return int_type(0);

    if (pptr() == epptr())

    {

        if ((__strmode_ & __dynamic) == 0 || (__strmode_ & __frozen) != 0)

            return int_type(EOF);

        size_t old_size = static_cast<size_t> ((epptr() ? epptr() : egptr()) - eback());

        size_t new_size = max<size_t>(static_cast<size_t>(__alsize_), 2*old_size);

        if (new_size == 0)

            new_size = __default_alsize;

        char* buf = nullptr;

        if (__palloc_)

            buf = static_cast<char*>(__palloc_(new_size));

        else

            buf = new char[new_size];

        if (buf == nullptr)

            return int_type(EOF);

        if (old_size != 0) {

            _LIBCPP_ASSERT(eback(), "overflow copying from NULL");

            memcpy(buf, eback(), static_cast<size_t>(old_size));

        }

        ptrdiff_t ninp = gptr()  - eback();

        ptrdiff_t einp = egptr() - eback();

        ptrdiff_t nout = pptr()  - pbase();

        if (__strmode_ & __allocated)

        {

            if (__pfree_)

                __pfree_(eback());

            else

                delete [] eback();

        }

        setg(buf, buf + ninp, buf + einp);

        setp(buf + einp, buf + new_size);

        __pbump(nout);

        __strmode_ |= __allocated;

    }

    *pptr() = static_cast<char>(__c);

    pbump(1);

    return int_type(static_cast<unsigned char>(__c));

}

strstreambuf::int_type

strstreambuf::pbackfail(int_type __c)

{

    if (eback() == gptr())

        return EOF;

    if (__c == EOF)

    {

        gbump(-1);

        return int_type(0);

    }

    if (__strmode_ & __constant)

    {

        if (gptr()[-1] == static_cast<char>(__c))

        {

            gbump(-1);

            return __c;

        }

        return EOF;

    }

    gbump(-1);

    *gptr() = static_cast<char>(__c);

    return __c;

}

strstreambuf::int_type

strstreambuf::underflow()

{

    if (gptr() == egptr())

    {

        if (egptr() >= pptr())

            return EOF;

        setg(eback(), gptr(), pptr());

    }

    return int_type(static_cast<unsigned char>(*gptr()));

}

strstreambuf::pos_type

strstreambuf::seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __which)

{

    off_type __p(-1);

    bool pos_in = (__which & ios::in) != 0;

    bool pos_out = (__which & ios::out) != 0;

    bool legal = false;

    switch (__way)

    {

    case ios::beg:

    case ios::end:

        if (pos_in || pos_out)

            legal = true;

        break;

    case ios::cur:

        if (pos_in != pos_out)

            legal = true;

        break;

    }

    if (pos_in && gptr() == nullptr)

        legal = false;

    if (pos_out && pptr() == nullptr)

        legal = false;

    if (legal)

    {

        off_type newoff;

        char* seekhigh = epptr() ? epptr() : egptr();

        switch (__way)

        {

        case ios::beg:

            newoff = 0;

            break;

        case ios::cur:

            newoff = (pos_in ? gptr() : pptr()) - eback();

            break;

        case ios::end:

            newoff = seekhigh - eback();

            break;

        default:

            _LIBCPP_UNREACHABLE();

        }

        newoff += __off;

        if (0 <= newoff && newoff <= seekhigh - eback())

        {

            char* newpos = eback() + newoff;

            if (pos_in)

                setg(eback(), newpos, _VSTD::max(newpos, egptr()));

            if (pos_out)

            {

                // min(pbase, newpos), newpos, epptr()

                __off = epptr() - newpos;

                setp(min(pbase(), newpos), epptr());

                __pbump((epptr() - pbase()) - __off);

            }

            __p = newoff;

        }

    }

    return pos_type(__p);

}

strstreambuf::pos_type

strstreambuf::seekpos(pos_type __sp, ios_base::openmode __which)

{

    off_type __p(-1);

    bool pos_in = (__which & ios::in) != 0;

    bool pos_out = (__which & ios::out) != 0;

    if (pos_in || pos_out)

    {

        if (!((pos_in && gptr() == nullptr) || (pos_out && pptr() == nullptr)))

        {

            off_type newoff = __sp;

            char* seekhigh = epptr() ? epptr() : egptr();

            if (0 <= newoff && newoff <= seekhigh - eback())

            {

                char* newpos = eback() + newoff;

                if (pos_in)

                    setg(eback(), newpos, _VSTD::max(newpos, egptr()));

                if (pos_out)

                {

                    // min(pbase, newpos), newpos, epptr()

                    off_type temp = epptr() - newpos;

                    setp(min(pbase(), newpos), epptr());

                    __pbump((epptr() - pbase()) - temp);

                }

                __p = newoff;

            }

        }

    }

    return pos_type(__p);

}

istrstream::~istrstream()

{

}

ostrstream::~ostrstream()

{

}

strstream::~strstream()

{

}

_LIBCPP_END_NAMESPACE_STD