You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
432 lines
14 KiB
432 lines
14 KiB
// (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
|
|
|