coco
186 lines
5.2 KiB
C++
186 lines
5.2 KiB
C++
// Copyright (C) 2003 Davis E. King (davis@dlib.net)
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// License: Boost Software License See LICENSE.txt for the full license.
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#undef DLIB_BIT_STREAM_KERNEl_ABSTRACT_
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#ifdef DLIB_BIT_STREAM_KERNEl_ABSTRACT_
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#include <iosfwd>
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namespace dlib
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{
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class bit_stream
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{
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/*!
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INITIAL VALUE
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is_in_write_mode() == false
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is_in_read_mode() == false
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WHAT THIS OBJECT REPRESENTS
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this object is a middle man between a user and the iostream classes.
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it allows single bits to be read/written easily to/from
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the iostream classes
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BUFFERING:
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This object will only read/write single bytes at a time from/to the
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iostream objects. Any buffered bits still in the bit_stream object
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when it is closed or destructed are lost if it is in read mode. If
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it is in write mode then any remaining bits are guaranteed to be
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written to the output stream by the time it is closed or destructed.
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!*/
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public:
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bit_stream (
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);
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/*!
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ensures
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- #*this is properly initialized
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throws
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- std::bad_alloc
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!*/
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virtual ~bit_stream (
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);
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/*!
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ensures
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- all memory associated with *this has been released
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!*/
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void clear (
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);
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/*!
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ensures
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- #*this has its initial value
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throws
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- std::bad_alloc
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if this exception is thrown then *this is unusable
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until clear() is called and succeeds
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!*/
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void set_input_stream (
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std::istream& is
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);
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/*!
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requires
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- is_in_write_mode() == false
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- is_in_read_mode() == false
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- is is ready to give input
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ensures
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- #is_in_write_mode() == false
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- #is_in_read_mode() == true
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- #*this will now be reading from is
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throws
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- std::bad_alloc
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!*/
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void set_output_stream (
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std::ostream& os
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);
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/*!
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requires
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- is_in_write_mode() == false
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- is_in_read_mode() == false
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- os is ready to take output
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ensures
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- #is_in_write_mode() == true
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- #is_in_read_mode() == false
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- #*this will now write to os
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throws
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- std::bad_alloc
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!*/
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void close (
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);
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/*!
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requires
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- is_in_write_mode() == true || is_in_read_mode() == true
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ensures
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- #is_in_write_mode() == false
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- #is_in_read_mode() == false
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!*/
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bool is_in_write_mode (
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) const;
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/*!
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ensures
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- returns true if *this is associated with an output stream object
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- returns false otherwise
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!*/
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bool is_in_read_mode (
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) const;
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/*!
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ensures
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- returns true if *this is associated with an input stream object
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- returns false otherwise
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!*/
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void write (
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int bit
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);
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/*!
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requires
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- is_in_write_mode() == true
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- bit == 0 || bit == 1
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ensures
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- bit will be written to the ostream object associated with *this
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throws
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- std::ios_base::failure
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if (there was a problem writing to the output stream) then
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this exception will be thrown. #*this will be unusable until
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clear() is called and succeeds
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- any other exception
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if this exception is thrown then #*this is unusable
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until clear() is called and succeeds
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!*/
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bool read (
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int& bit
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);
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/*!
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requires
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- is_in_read_mode() == true
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ensures
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- the next bit has been read and placed into #bit
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- returns true if the read was successful, else false
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(ex. false if EOF has been reached)
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throws
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- any exception
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if this exception is thrown then #*this is unusable
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until clear() is called and succeeds
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!*/
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void swap (
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bit_stream& item
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);
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/*!
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ensures
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- swaps *this and item
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!*/
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private:
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// restricted functions
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bit_stream(bit_stream&); // copy constructor
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bit_stream& operator=(bit_stream&); // assignment operator
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};
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inline void swap (
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bit_stream& a,
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bit_stream& b
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) { a.swap(b); }
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/*!
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provides a global swap function
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!*/
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}
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#endif // DLIB_BIT_STREAM_KERNEl_ABSTRACT_
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