// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) | |
// (C) Copyright 2003-2007 Jonathan Turkanis | |
// Distributed under the Boost Software License, Version 1.0. (See accompanying | |
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) | |
// See http://www.boost.org/libs/iostreams for documentation. | |
// This material is heavily indebted to the discussion and code samples in | |
// A. Langer and K. Kreft, "Standard C++ IOStreams and Locales", | |
// Addison-Wesley, 2000, pp. 228-43. | |
// User "GMSB" provided an optimization for small seeks. | |
#ifndef BOOST_IOSTREAMS_DETAIL_INDIRECT_STREAMBUF_HPP_INCLUDED | |
#define BOOST_IOSTREAMS_DETAIL_INDIRECT_STREAMBUF_HPP_INCLUDED | |
#include <algorithm> // min, max. | |
#include <cassert> | |
#include <exception> | |
#include <typeinfo> | |
#include <boost/config.hpp> // Member template friends. | |
#include <boost/detail/workaround.hpp> | |
#include <boost/iostreams/constants.hpp> | |
#include <boost/iostreams/detail/adapter/concept_adapter.hpp> | |
#include <boost/iostreams/detail/buffer.hpp> | |
#include <boost/iostreams/detail/config/wide_streams.hpp> | |
#include <boost/iostreams/detail/double_object.hpp> | |
#include <boost/iostreams/detail/execute.hpp> | |
#include <boost/iostreams/detail/functional.hpp> | |
#include <boost/iostreams/detail/ios.hpp> | |
#include <boost/iostreams/detail/optional.hpp> | |
#include <boost/iostreams/detail/push.hpp> | |
#include <boost/iostreams/detail/streambuf/linked_streambuf.hpp> | |
#include <boost/iostreams/operations.hpp> | |
#include <boost/iostreams/positioning.hpp> | |
#include <boost/iostreams/traits.hpp> | |
#include <boost/iostreams/operations.hpp> | |
#include <boost/mpl/if.hpp> | |
#include <boost/throw_exception.hpp> | |
#include <boost/type_traits/is_convertible.hpp> | |
// Must come last. | |
#include <boost/iostreams/detail/config/disable_warnings.hpp> // MSVC, BCC 5.x | |
namespace boost { namespace iostreams { namespace detail { | |
// | |
// Description: The implementation of basic_streambuf used by chains. | |
// | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
class indirect_streambuf | |
: public linked_streambuf<BOOST_DEDUCED_TYPENAME char_type_of<T>::type, Tr> | |
{ | |
public: | |
typedef typename char_type_of<T>::type char_type; | |
BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr) | |
private: | |
typedef typename category_of<T>::type category; | |
typedef concept_adapter<T> wrapper; | |
typedef detail::basic_buffer<char_type, Alloc> buffer_type; | |
typedef indirect_streambuf<T, Tr, Alloc, Mode> my_type; | |
typedef detail::linked_streambuf<char_type, traits_type> base_type; | |
typedef linked_streambuf<char_type, Tr> streambuf_type; | |
public: | |
indirect_streambuf(); | |
void open(const T& t BOOST_IOSTREAMS_PUSH_PARAMS()); | |
bool is_open() const; | |
void close(); | |
bool auto_close() const; | |
void set_auto_close(bool close); | |
bool strict_sync(); | |
// Declared in linked_streambuf. | |
T* component() { return &*obj(); } | |
protected: | |
#if !BOOST_WORKAROUND(__GNUC__, == 2) | |
BOOST_IOSTREAMS_USING_PROTECTED_STREAMBUF_MEMBERS(base_type) | |
#endif | |
//----------virtual functions---------------------------------------------// | |
#ifndef BOOST_IOSTREAMS_NO_LOCALE | |
void imbue(const std::locale& loc); | |
#endif | |
#ifdef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES | |
public: | |
#endif | |
int_type underflow(); | |
int_type pbackfail(int_type c); | |
int_type overflow(int_type c); | |
int sync(); | |
pos_type seekoff( off_type off, BOOST_IOS::seekdir way, | |
BOOST_IOS::openmode which ); | |
pos_type seekpos(pos_type sp, BOOST_IOS::openmode which); | |
// Declared in linked_streambuf. | |
void set_next(streambuf_type* next); | |
void close_impl(BOOST_IOS::openmode m); | |
const std::type_info& component_type() const { return typeid(T); } | |
void* component_impl() { return component(); } | |
private: | |
//----------Accessor functions--------------------------------------------// | |
wrapper& obj() { return *storage_; } | |
streambuf_type* next() const { return next_; } | |
buffer_type& in() { return buffer_.first(); } | |
buffer_type& out() { return buffer_.second(); } | |
bool can_read() const { return is_convertible<Mode, input>::value; } | |
bool can_write() const { return is_convertible<Mode, output>::value; } | |
bool output_buffered() const { return (flags_ & f_output_buffered) != 0; } | |
bool shared_buffer() const { return is_convertible<Mode, seekable>::value; } | |
void set_flags(int f) { flags_ = f; } | |
//----------State changing functions--------------------------------------// | |
virtual void init_get_area(); | |
virtual void init_put_area(); | |
//----------Utility function----------------------------------------------// | |
pos_type seek_impl( stream_offset off, BOOST_IOS::seekdir way, | |
BOOST_IOS::openmode which ); | |
void sync_impl(); | |
enum flag_type { | |
f_open = 1, | |
f_output_buffered = f_open << 1, | |
f_auto_close = f_output_buffered << 1 | |
}; | |
optional<wrapper> storage_; | |
streambuf_type* next_; | |
double_object< | |
buffer_type, | |
is_convertible< | |
Mode, | |
two_sequence | |
> | |
> buffer_; | |
std::streamsize pback_size_; | |
int flags_; | |
}; | |
//--------------Implementation of indirect_streambuf--------------------------// | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
indirect_streambuf<T, Tr, Alloc, Mode>::indirect_streambuf() | |
: next_(0), pback_size_(0), flags_(f_auto_close) { } | |
//--------------Implementation of open, is_open and close---------------------// | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
void indirect_streambuf<T, Tr, Alloc, Mode>::open | |
(const T& t, std::streamsize buffer_size, std::streamsize pback_size) | |
{ | |
using namespace std; | |
// Normalize buffer sizes. | |
buffer_size = | |
(buffer_size != -1) ? | |
buffer_size : | |
iostreams::optimal_buffer_size(t); | |
pback_size = | |
(pback_size != -1) ? | |
pback_size : | |
default_pback_buffer_size; | |
// Construct input buffer. | |
if (can_read()) { | |
pback_size_ = (std::max)(std::streamsize(2), pback_size); // STLPort needs 2. | |
std::streamsize size = | |
pback_size_ + | |
( buffer_size ? buffer_size: 1 ); | |
in().resize(size); | |
if (!shared_buffer()) | |
init_get_area(); | |
} | |
// Construct output buffer. | |
if (can_write() && !shared_buffer()) { | |
if (buffer_size != 0) | |
out().resize(buffer_size); | |
init_put_area(); | |
} | |
storage_.reset(wrapper(t)); | |
flags_ |= f_open; | |
if (can_write() && buffer_size > 1) | |
flags_ |= f_output_buffered; | |
this->set_true_eof(false); | |
this->set_needs_close(); | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
inline bool indirect_streambuf<T, Tr, Alloc, Mode>::is_open() const | |
{ return (flags_ & f_open) != 0; } | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
void indirect_streambuf<T, Tr, Alloc, Mode>::close() | |
{ | |
using namespace std; | |
base_type* self = this; | |
detail::execute_all( | |
detail::call_member_close(*self, BOOST_IOS::in), | |
detail::call_member_close(*self, BOOST_IOS::out), | |
detail::call_reset(storage_), | |
detail::clear_flags(flags_) | |
); | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
bool indirect_streambuf<T, Tr, Alloc, Mode>::auto_close() const | |
{ return (flags_ & f_auto_close) != 0; } | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
void indirect_streambuf<T, Tr, Alloc, Mode>::set_auto_close(bool close) | |
{ flags_ = (flags_ & ~f_auto_close) | (close ? f_auto_close : 0); } | |
//--------------Implementation virtual functions------------------------------// | |
#ifndef BOOST_IOSTREAMS_NO_LOCALE | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
void indirect_streambuf<T, Tr, Alloc, Mode>::imbue(const std::locale& loc) | |
{ | |
if (is_open()) { | |
obj().imbue(loc); | |
if (next_) | |
next_->pubimbue(loc); | |
} | |
} | |
#endif | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
typename indirect_streambuf<T, Tr, Alloc, Mode>::int_type | |
indirect_streambuf<T, Tr, Alloc, Mode>::underflow() | |
{ | |
using namespace std; | |
if (!gptr()) init_get_area(); | |
buffer_type& buf = in(); | |
if (gptr() < egptr()) return traits_type::to_int_type(*gptr()); | |
// Fill putback buffer. | |
std::streamsize keep = | |
(std::min)( static_cast<std::streamsize>(gptr() - eback()), | |
pback_size_ ); | |
if (keep) | |
traits_type::move( buf.data() + (pback_size_ - keep), | |
gptr() - keep, keep ); | |
// Set pointers to reasonable values in case read throws. | |
setg( buf.data() + pback_size_ - keep, | |
buf.data() + pback_size_, | |
buf.data() + pback_size_ ); | |
// Read from source. | |
std::streamsize chars = | |
obj().read(buf.data() + pback_size_, buf.size() - pback_size_, next_); | |
if (chars == -1) { | |
this->set_true_eof(true); | |
chars = 0; | |
} | |
setg(eback(), gptr(), buf.data() + pback_size_ + chars); | |
return chars != 0 ? | |
traits_type::to_int_type(*gptr()) : | |
traits_type::eof(); | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
typename indirect_streambuf<T, Tr, Alloc, Mode>::int_type | |
indirect_streambuf<T, Tr, Alloc, Mode>::pbackfail(int_type c) | |
{ | |
if (gptr() != eback()) { | |
gbump(-1); | |
if (!traits_type::eq_int_type(c, traits_type::eof())) | |
*gptr() = traits_type::to_char_type(c); | |
return traits_type::not_eof(c); | |
} else { | |
boost::throw_exception(bad_putback()); | |
} | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
typename indirect_streambuf<T, Tr, Alloc, Mode>::int_type | |
indirect_streambuf<T, Tr, Alloc, Mode>::overflow(int_type c) | |
{ | |
if ( (output_buffered() && pptr() == 0) || | |
(shared_buffer() && gptr() != 0) ) | |
{ | |
init_put_area(); | |
} | |
if (!traits_type::eq_int_type(c, traits_type::eof())) { | |
if (output_buffered()) { | |
if (pptr() == epptr()) { | |
sync_impl(); | |
if (pptr() == epptr()) | |
return traits_type::eof(); | |
} | |
*pptr() = traits_type::to_char_type(c); | |
pbump(1); | |
} else { | |
char_type d = traits_type::to_char_type(c); | |
if (obj().write(&d, 1, next_) != 1) | |
return traits_type::eof(); | |
} | |
} | |
return traits_type::not_eof(c); | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
int indirect_streambuf<T, Tr, Alloc, Mode>::sync() | |
{ | |
try { // sync() is no-throw. | |
sync_impl(); | |
obj().flush(next_); | |
return 0; | |
} catch (...) { return -1; } | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
bool indirect_streambuf<T, Tr, Alloc, Mode>::strict_sync() | |
{ | |
try { // sync() is no-throw. | |
sync_impl(); | |
return obj().flush(next_); | |
} catch (...) { return false; } | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
inline typename indirect_streambuf<T, Tr, Alloc, Mode>::pos_type | |
indirect_streambuf<T, Tr, Alloc, Mode>::seekoff | |
(off_type off, BOOST_IOS::seekdir way, BOOST_IOS::openmode which) | |
{ return seek_impl(off, way, which); } | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
inline typename indirect_streambuf<T, Tr, Alloc, Mode>::pos_type | |
indirect_streambuf<T, Tr, Alloc, Mode>::seekpos | |
(pos_type sp, BOOST_IOS::openmode which) | |
{ | |
return seek_impl(position_to_offset(sp), BOOST_IOS::beg, which); | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
typename indirect_streambuf<T, Tr, Alloc, Mode>::pos_type | |
indirect_streambuf<T, Tr, Alloc, Mode>::seek_impl | |
(stream_offset off, BOOST_IOS::seekdir way, BOOST_IOS::openmode which) | |
{ | |
if ( gptr() != 0 && way == BOOST_IOS::cur && which == BOOST_IOS::in && | |
eback() - gptr() <= off && off <= egptr() - gptr() ) | |
{ // Small seek optimization | |
gbump(off); | |
return obj().seek(0, BOOST_IOS::cur, BOOST_IOS::in, next_) - | |
static_cast<off_type>(egptr() - gptr()); | |
} | |
if (pptr() != 0) | |
this->BOOST_IOSTREAMS_PUBSYNC(); // sync() confuses VisualAge 6. | |
if (way == BOOST_IOS::cur && gptr()) | |
off -= static_cast<off_type>(egptr() - gptr()); | |
setg(0, 0, 0); | |
setp(0, 0); | |
return obj().seek(off, way, which, next_); | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
inline void indirect_streambuf<T, Tr, Alloc, Mode>::set_next | |
(streambuf_type* next) | |
{ next_ = next; } | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
inline void indirect_streambuf<T, Tr, Alloc, Mode>::close_impl | |
(BOOST_IOS::openmode which) | |
{ | |
if (which == BOOST_IOS::in && is_convertible<Mode, input>::value) { | |
setg(0, 0, 0); | |
} | |
if (which == BOOST_IOS::out && is_convertible<Mode, output>::value) { | |
sync(); | |
setp(0, 0); | |
} | |
if ( !is_convertible<category, dual_use>::value || | |
is_convertible<Mode, input>::value == (which == BOOST_IOS::in) ) | |
{ | |
obj().close(which, next_); | |
} | |
} | |
//----------State changing functions------------------------------------------// | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
void indirect_streambuf<T, Tr, Alloc, Mode>::sync_impl() | |
{ | |
std::streamsize avail, amt; | |
if ((avail = static_cast<std::streamsize>(pptr() - pbase())) > 0) { | |
if ((amt = obj().write(pbase(), avail, next())) == avail) | |
setp(out().begin(), out().end()); | |
else { | |
const char_type* ptr = pptr(); | |
setp(out().begin() + amt, out().end()); | |
pbump(ptr - pptr()); | |
} | |
} | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
void indirect_streambuf<T, Tr, Alloc, Mode>::init_get_area() | |
{ | |
if (shared_buffer() && pptr() != 0) { | |
sync_impl(); | |
setp(0, 0); | |
} | |
setg(in().begin(), in().begin(), in().begin()); | |
} | |
template<typename T, typename Tr, typename Alloc, typename Mode> | |
void indirect_streambuf<T, Tr, Alloc, Mode>::init_put_area() | |
{ | |
using namespace std; | |
if (shared_buffer() && gptr() != 0) | |
setg(0, 0, 0); | |
if (output_buffered()) | |
setp(out().begin(), out().end()); | |
else | |
setp(0, 0); | |
} | |
//----------------------------------------------------------------------------// | |
} } } // End namespaces detail, iostreams, boost. | |
#include <boost/iostreams/detail/config/enable_warnings.hpp> // MSVC, BCC 5.x | |
#endif // #ifndef BOOST_IOSTREAMS_DETAIL_INDIRECT_STREAMBUF_HPP_INCLUDED |