uSTL_2.3/include/mostream.h

295 lines
9.4 KiB
C++

// This file is part of the uSTL library, an STL implementation.
//
// Copyright (c) 2005 by Mike Sharov <msharov@users.sourceforge.net>
// This file is free software, distributed under the MIT License.
#pragma once
#include "memlink.h"
#include "utf8.h"
#include "uios.h"
#include "strmsize.h"
#if WANT_STREAM_BOUNDS_CHECKING
#include "typeinfo.h"
#endif
namespace ustl {
class istream;
class string;
/// \class ostream mostream.h ustl.h
/// \ingroup BinaryStreams
///
/// \brief Helper class to write packed binary streams.
///
/// This class contains a set of functions to write integral types into an
/// unstructured memory block. Packing binary file data can be done this
/// way, for instance. aligning the data is your responsibility, and can
/// be accomplished by proper ordering of writes and by calling align.
/// Unaligned access is usually slower by orders of magnitude and,
/// on some architectures, such as PowerPC, can cause your program to crash.
/// Therefore, all write functions have asserts to check alignment.
/// See \ref istream documentation for rules on designing your data format.
/// Overwriting the end of the stream will also cause a crash (an assert in
/// debug builds). Oh, and don't be intimidated by the size of the inlines
/// here. In the assembly code the compiler will usually chop everything down
/// to five instructions each.
///
/// Example code:
/// \code
/// memblock b;
/// ostream os (b);
/// os << boolVar << ios::talign<int>();
/// os << intVar << floatVar;
/// os.write (binaryData, binaryDataSize);
/// os.align();
/// b.resize (os.pos());
/// b.write_file ("test.file");
/// \endcode
///
class ostream : public memlink, public ios_base {
public:
inline ostream (void);
inline ostream (void* p, streamsize n);
inline explicit ostream (const memlink& source);
inline iterator end (void) { return (memlink::end()); }
inline const_iterator end (void) const { return (memlink::end()); }
inline void seek (uoff_t newPos);
inline void iseek (const_iterator newPos);
inline void skip (streamsize nBytes);
inline uoff_t pos (void) const { return (m_Pos); }
inline iterator ipos (void) { return (begin() + pos()); }
inline const_iterator ipos (void) const { return (begin() + pos()); }
inline streamsize remaining (void) const;
inline bool aligned (streamsize grain = c_DefaultAlignment) const;
bool verify_remaining (const char* op, const char* type, size_t n);
inline streamsize align_size (streamsize grain = c_DefaultAlignment) const;
void align (streamsize grain = c_DefaultAlignment);
inline void write (const void* buffer, streamsize size);
inline void write (const cmemlink& buf);
void write_strz (const char* str);
void read (istream& is);
inline void write (ostream& os) const { os.write (begin(), pos()); }
void text_write (ostringstream& os) const;
inline size_t stream_size (void) const { return (pos()); }
void insert (iterator start, streamsize size);
void erase (iterator start, streamsize size);
inline void swap (ostream& os);
template <typename T>
inline void iwrite (const T& v);
inline streamsize overflow (streamsize = 1){ return (remaining()); }
void unlink (void) noexcept;
inline void link (void* p, streamsize n) { memlink::link (p, n); }
inline void link (memlink& l) { memlink::link (l.data(), l.writable_size()); }
inline void link (void* f, void* l) { memlink::link (f, l); }
inline void relink (void* p, streamsize n) { memlink::relink (p, n); m_Pos = 0; }
inline void relink (memlink& l) { relink (l.data(), l.writable_size()); }
inline void seekp (off_t p, seekdir d = beg);
inline off_t tellp (void) const { return (pos()); }
protected:
inline void SetPos (uoff_t newPos) { m_Pos = newPos; }
private:
streamoff m_Pos; ///< Current write position.
};
//----------------------------------------------------------------------
/// \class ostream_iterator mostream.h ustl.h
/// \ingroup BinaryStreamIterators
///
/// \brief An iterator over an ostream to use with uSTL algorithms.
///
template <typename T, typename Stream = ostream>
class ostream_iterator {
public:
typedef T value_type;
typedef ptrdiff_t difference_type;
typedef value_type* pointer;
typedef value_type& reference;
typedef typename Stream::size_type size_type;
public:
inline explicit ostream_iterator (Stream& os)
: m_Os (os) {}
inline ostream_iterator (const ostream_iterator& iter)
: m_Os (iter.m_Os) {}
/// Writes \p v into the stream.
inline ostream_iterator& operator= (const T& v)
{ m_Os << v; return (*this); }
inline ostream_iterator& operator* (void) { return (*this); }
inline ostream_iterator& operator++ (void) { return (*this); }
inline ostream_iterator operator++ (int) { return (*this); }
inline ostream_iterator& operator+= (streamsize n) { m_Os.skip (n); return (*this); }
inline bool operator== (const ostream_iterator& i) const
{ return (m_Os.pos() == i.m_Os.pos()); }
inline bool operator< (const ostream_iterator& i) const
{ return (m_Os.pos() < i.m_Os.pos()); }
private:
Stream& m_Os;
};
//----------------------------------------------------------------------
typedef ostream_iterator<utf8subchar_t> ostream_iterator_for_utf8;
typedef utf8out_iterator<ostream_iterator_for_utf8> utf8ostream_iterator;
/// Returns a UTF-8 adaptor writing to \p os.
inline utf8ostream_iterator utf8out (ostream& os)
{
ostream_iterator_for_utf8 si (os);
return (utf8ostream_iterator (si));
}
//----------------------------------------------------------------------
/// \brief Constructs a stream attached to nothing.
/// A stream attached to nothing is not usable. Call Link() functions
/// inherited from memlink to attach to some memory block.
///
inline ostream::ostream (void)
: memlink (),
m_Pos (0)
{
}
/// Attaches the stream to a block at \p p of size \p n.
inline ostream::ostream (void* p, streamsize n)
: memlink (p, n),
m_Pos (0)
{
}
/// Attaches to the block pointed to by \p source.
inline ostream::ostream (const memlink& source)
: memlink (source),
m_Pos (0)
{
}
/// Checks that \p n bytes are available in the stream, or else throws.
inline bool ostream::verify_remaining (const char* op, const char* type, size_t n)
{
const size_t rem = remaining();
bool enough = n <= rem;
if (!enough) overrun (op, type, n, pos(), rem);
return (enough);
}
/// Move the write pointer to \p newPos
inline void ostream::seek (uoff_t newPos)
{
#if WANT_STREAM_BOUNDS_CHECKING
if (newPos > size())
return;
#else
assert (newPos <= size());
#endif
SetPos (newPos);
}
/// Sets the current write position to \p newPos
inline void ostream::iseek (const_iterator newPos)
{
seek (distance (begin(), const_cast<iterator>(newPos)));
}
/// Sets the current write position to \p p based on \p d.
inline void ostream::seekp (off_t p, seekdir d)
{
switch (d) {
case beg: seek (p); break;
case cur: seek (pos() + p); break;
case ios_base::end: seek (size() - p); break;
}
}
/// Skips \p nBytes without writing anything.
inline void ostream::skip (streamsize nBytes)
{
seek (pos() + nBytes);
}
/// Returns number of bytes remaining in the write buffer.
inline streamsize ostream::remaining (void) const
{
return (size() - pos());
}
/// Returns \c true if the write pointer is aligned on \p grain
inline bool ostream::aligned (streamsize grain) const
{
assert (uintptr_t(begin()) % grain == 0 && "Streams should be attached aligned at the maximum element grain to avoid bus errors.");
return (pos() % grain == 0);
}
/// Returns the number of bytes to skip to be aligned on \p grain.
inline streamsize ostream::align_size (streamsize grain) const
{
return (Align (pos(), grain) - pos());
}
/// Writes \p n bytes from \p buffer.
inline void ostream::write (const void* buffer, size_type n)
{
#if WANT_STREAM_BOUNDS_CHECKING
if (!verify_remaining ("write", "binary data", n))
return;
#else
assert (remaining() >= n && "Buffer overrun. Check your stream size calculations.");
#endif
memcpy (ipos(), const_iterator(buffer), n);
m_Pos += n;
}
/// Writes the contents of \p buf into the stream as a raw dump.
inline void ostream::write (const cmemlink& buf)
{
write (buf.begin(), buf.size());
}
/// Writes type T into the stream via a direct pointer cast.
template <typename T>
inline void ostream::iwrite (const T& v)
{
assert (aligned (stream_align_of (v)));
#if WANT_STREAM_BOUNDS_CHECKING
if (!verify_remaining ("write", typeid(v).name(), sizeof(T)))
return;
#else
assert (remaining() >= sizeof(T));
#endif
*reinterpret_cast<T*>(ipos()) = v;
SetPos (pos() + sizeof(T));
}
/// Swaps with \p os
inline void ostream::swap (ostream& os)
{
memlink::swap (os);
::ustl::swap (m_Pos, os.m_Pos);
}
//----------------------------------------------------------------------
template <typename T> struct object_writer {
inline void operator()(ostream& os, const T& v) const { v.write (os); }
};
template <typename T> struct integral_object_writer {
inline void operator()(ostream& os, const T& v) const { os.iwrite (v); }
};
template <typename T>
inline ostream& operator<< (ostream& os, const T& v)
{
return (os);
}
template <typename T>
inline ostream& operator<< (ostream& os, const T* v)
{
for (; *v; ++v)
os << v;
return (os);
}
//----------------------------------------------------------------------
} // namespace ustl