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Diffstat (limited to 'ml/dlib/dlib/lz77_buffer/lz77_buffer_kernel_abstract.h')
| -rw-r--r-- | ml/dlib/dlib/lz77_buffer/lz77_buffer_kernel_abstract.h | 210 |
1 files changed, 0 insertions, 210 deletions
diff --git a/ml/dlib/dlib/lz77_buffer/lz77_buffer_kernel_abstract.h b/ml/dlib/dlib/lz77_buffer/lz77_buffer_kernel_abstract.h deleted file mode 100644 index 942b4e3c2..000000000 --- a/ml/dlib/dlib/lz77_buffer/lz77_buffer_kernel_abstract.h +++ /dev/null @@ -1,210 +0,0 @@ -// Copyright (C) 2004 Davis E. King (davis@dlib.net) -// License: Boost Software License See LICENSE.txt for the full license. -#undef DLIB_LZ77_BUFFER_KERNEl_ABSTRACT_ -#ifdef DLIB_LZ77_BUFFER_KERNEl_ABSTRACT_ - -#include "../algs.h" - -namespace dlib -{ - - class lz77_buffer - { - /*! - INITIAL VALUE - get_history_buffer_limit() == defined by constructor arguments - get_lookahead_buffer_limit() == defined by constructor arguments - get_history_buffer_size() == 0 - get_lookahead_buffer_size() == 0 - - - WHAT THIS OBJECT REPRESENTS - This object represents a pair of buffers (history and lookahead buffers) - used during lz77 style compression. - - It's main function is to search the history buffer for long strings which - match the contents (or a part of the contents) of the lookahead buffer. - - - HISTORY AND LOOKAHEAD BUFFERS - The buffers have the following structure: - | history buffer | lookahead buffer | <-- contents of buffers - | ...9876543210 | 0123456789... | <-- index numbers - - So this means that history_buffer(0) == 'r', history_buffer(1) == 'e' - and so on. And lookahead_buffer(0) == 'l', lookahead_buffer(1) == 'o' - and so on. - - - What shift_buffers() does in english: - This function just means that the buffers have their contents shifted - left by N elements and that elements shifted out of the lookahead buffer - go into the history buffer. An example will make it clearer. - - Suppose that we have the following buffers before we apply shift_buffers() - history_buffer() == "hey" and - lookahead_buffer() == "lookahead buffer" - And in the same format as the above diagram it would be - | hey | lookahead buffer | <-- contents of buffers - | 210 | 0123456789... | <-- index numbers - - Applying shift_buffers(4) will give - lookahead_buffer() == "ahead buffer" - history_buffer() == "heylook" or "eylook" or "ylook" or "look" - - You might be wondering why the history_buffer can resize itself in - such a nondeterministic way. It is just to allow a lot of freedom in the - implementations of this object. - !*/ - - public: - - lz77_buffer ( - unsigned long total_limit, - unsigned long lookahead_limit - ); - /*! - requires - - 6 < total_limit < 32 - - 15 < lookahead_limit <= 2^(total_limit-2) - ensures - - #*this is properly initialized - - #get_history_buffer_limit() == 2^total_limit - lookahead_limit - - #get_lookahead_buffer_limit() == lookahead_limit - throws - - std::bad_alloc - !*/ - - virtual ~lz77_buffer ( - ); - /*! - ensures - - any resources associated with *this have been released - !*/ - - void clear( - ); - /*! - ensures - - #*this has its initial value - throws - - std::bad_alloc - if this exception is thrown then #*this is unusable - until clear() is called and succeeds - !*/ - - void shift_buffers ( - unsigned long N - ); - /*! - requires - - N <= get_lookahead_buffer_size() - ensures - - #get_lookahead_buffer_size() == get_lookahead_buffer_size() - N - - #get_history_buffer_size() >= N - - #get_history_buffer_size() <= get_history_buffer_size()+N - - #get_history_buffer_size() <= get_history_buffer_limit() - - for all i where 0 <= i < N: - #history_buffer(N-1-i) == lookahead_buffer(i) - - for all i where 0 <= i < #get_history_buffer_size()-N: - #history_buffer(N+i) == history_buffer(i) - - for all i where 0 <= i < #get_lookahead_buffer_size() - #lookahead_buffer(i) == lookahead_buffer(N+i) - !*/ - - void add ( - unsigned char symbol - ); - /*! - ensures - - if (get_lookahead_buffer_size() == get_lookahead_buffer_limit()) then - - performs shift_buffers(1) - - #lookahead_buffer(get_lookahead_buffer_limit()-1) == symbol - - #get_lookahead_buffer_size() == get_lookahead_buffer_size() - - else - - #lookahead_buffer(get_lookahead_buffer_size()) == symbol - - #get_lookahead_buffer_size() == get_lookahead_buffer_size() + 1 - throws - - std::bad_alloc - if this exception is thrown then #*this is unusable - until clear() is called and succeeds - !*/ - - void find_match ( - unsigned long& index, - unsigned long& length, - unsigned long min_match_length - ); - /*! - ensures - - if (#length != 0) then - - #length >= min_match_length - - for all i where 0 <= i < #length: - history_buffer(#index-i) == lookahead_buffer(i) - - performs shift_buffers(#length) - throws - - std::bad_alloc - if this exception is thrown then #*this is unusable - until clear() is called and succeeds - !*/ - - unsigned long get_history_buffer_limit ( - ) const; - /*! - ensures - - returns the max number of symbols that can fit in the history buffer - !*/ - - unsigned long get_lookahead_buffer_limit ( - ) const; - /*! - ensures - - returns the max number of symbols that can fit in the lookahead buffer - !*/ - - unsigned long get_history_buffer_size ( - ) const; - /*! - ensures - - returns the number of symbols currently in the history buffer - !*/ - - unsigned long get_lookahead_buffer_size ( - ) const; - /*! - ensures - - returns the number of symbols currently in the lookahead buffer - !*/ - - unsigned char lookahead_buffer ( - unsigned long index - ) const; - /*! - requires - - index < get_lookahead_buffer_size() - ensures - - returns the symbol in the lookahead buffer at location index - !*/ - - unsigned char history_buffer ( - unsigned long index - ) const; - /*! - requires - - index < get_history_buffer_size() - ensures - - returns the symbol in the history buffer at location index - !*/ - - - private: - - // restricted functions - lz77_buffer(lz77_buffer&); // copy constructor - lz77_buffer& operator=(lz77_buffer&); // assignment operator - - }; -} - -#endif // DLIB_LZ77_BUFFER_KERNEl_ABSTRACT_ - |