diff -r 5f8a03274d75 -r 6de6d9a64ebd sources/huffman/huffcodec.h --- a/sources/huffman/huffcodec.h Fri May 15 20:10:44 2015 +0300 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,182 +0,0 @@ -/* - * skulltag::HuffmanCodec class - Huffman encoder and decoder. - * - * Copyright 2009 Timothy Landers - * email: code.vortexcortex@gmail.com - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ - -#ifndef _HUFFMAN_CODEC_VERSION -#define _HUFFMAN_CODEC_VERSION 1 -#define _HUFFMAN_CODEC_REV 0 - -#include "codec.h" -#include "bitwriter.h" -#include "bitreader.h" - -/** Prevents naming convention problems via encapsulation. */ -namespace skulltag { - - /** HuffmanCodec class - Encodes and Decodes data using a Huffman tree. */ - class HuffmanCodec : public Codec { - - /** top level node of the Huffman tree used for decoding. */ - HuffmanNode * root; - - /** table of Huffman codes and bit lengths used for encoding. */ - HuffmanNode ** codeTable; - - /** intermediary destination of huffman codes. */ - BitWriter * writer; - - /** When true this HuffmanCodec reverses its bytes after encoding and before decoding to - * provide compatibility with the backwards bit ordering of the original ST Huffman Encoding. - * Default value is "false" (do not reverse bits). */ - bool reverseBits; - - /** When false this HuffmanCodec return -1 instead of expanding data during encoding. - * Default value is "true" (allow data expansion). */ - bool expandable; - - /** Determines if this HuffmanCodec owns its Huffman tree nodes. */ - bool huffResourceOwner; - - /** Reverses the order of bits in a byte. - * EG: The statement reverseMap[0xAF] == 0xF5 is true.
- * The index 10101111 stores the reverse value: 11110101.
- * Note: One array lookup is much faster than Eight bit manipulating loop iterations. */ - static unsigned char const reverseMap[]; - - /** Number of bits the shortest huffman code in the tree has. */ - int shortestCode; - - public: - - /** Creates a new HuffmanCodec from the Huffman tree data. - * @param treeData pointer to a buffer containing the Huffman tree structure definition. - * @param dataLength length in bytes of the Huffman tree structure data. */ - HuffmanCodec( unsigned char const * const treeData, int dataLength ); - - /** Creates a new HuffmanCodec that uses the specified Huffman resources. - * @param treeRootNode The root node of a valid huffman tree. - * @param leafCodeTable A code lookup table where references to HuffmanNodes are stored with their array index equal to their value. - * Note: The tree nodes will not be released upon destruction of this HuffmanCodec. */ - HuffmanCodec( - HuffmanNode * treeRootNode, - HuffmanNode ** leafCodeTable - ); - - /** Frees resources used internally by this HuffmanCodec. */ - virtual ~HuffmanCodec(); - - /** Decodes data read from an input buffer and stores the result in the output buffer. - * @return number of bytes stored in the output buffer or -1 if an error occurs while encoding. */ - virtual int encode( - unsigned char const * const input, /**< in: pointer to the first byte to encode. */ - unsigned char * const output, /**< out: pointer to an output buffer to store data. */ - int const &inLength, /**< in: number of bytes of input buffer to encoded. */ - int const &outLength /**< in: maximum length of data to output. */ - ) const; - - /** Decodes data read from an input buffer and stores the result in the output buffer. - * @return number of bytes stored in the output buffer or -1 if an error occurs while decoding. */ - virtual int decode( - unsigned char const * const input, /**< in: pointer to data that needs decoding. */ - unsigned char * const output, /**< out: pointer to output buffer to store decoded data. */ - int const &inLength, /**< in: number of bytes of input buffer to read. */ - int const &outLength /**< in: maximum length of data to output. */ - ); - - /** Enables or Disables backwards bit ordering of bytes. - * @param backwards "true" enables reversed bit order bytes, "false" uses standard byte bit ordering. */ - void reversedBytes( bool backwards ); - - /** Check the state of backwards bit ordering for bytes. - * @return true: bits within bytes are reversed. false: bits within bytes are normal. */ - bool reversedBytes(); - - /** Enable or Disable data expansion during encoding. - * @param expandingAllowed "true" allows encoding to expand data. "false" causes failure upon expansion. */ - void allowExpansion( bool expandable ); - - /** Check the state of data expandability. - * @return true: data expansion is allowed. false: data is not allowed to expand. */ - bool allowExpansion(); - - /** Sets the ownership of this HuffmanCodec's resources. - * @param ownsResources When false the tree will not be released upon destruction of this HuffmanCodec. - * When true deleting this HuffmanCodec will cause the Huffman tree to be released. */ - void huffmanResourceOwner( bool ownsResources ); - - /** Checks the ownership state of this HuffmanCodec's resources. - * @return ownsResources When false the tree will not be released upon destruction of this HuffmanCodec. - * When true deleting this HuffmanCodec will cause the Huffman tree to be released. */ - bool huffmanResourceOwner(); - - /** Deletes all sub nodes of a HuffmanNode by traversing and deleting its child nodes. - * @param treeNode pointer to a HuffmanNode whos children will be deleted. */ - static void deleteTree( HuffmanNode * treeNode ); - - /** Recursively builds a Huffman Tree.
- * The initial root node should have the following field values:
- *
-		 * bitCount : 0
-		 * code     : 0
-		 * value    : -1
-		 * branch   : 0 (NULL)
-		 * 
- * @param node in/out: branch node of the Huffman Tree. - * @param treeData in: char array containing the Huffman Tree's byte representation. - * @param index in: Current array element to read the next tree node from. - * @param dataLength in: Length of treeData - * @param codeTable in/out: array of pointers to HuffmanNode structs. - * @param tableLength in: maximum index allowed in the codeTable. - * @return the next index to read from or -1 if an error occurs. - * */ - int buildTree( - HuffmanNode * node, - unsigned char const * const treeData, - int index, - int dataLength, - HuffmanNode ** const &codeTable, - int tableLength - ); - - /** Decreases a codeLength to the shortest Huffman code bit length found in the node or any of its children.
- * Set to Zero before calling to determine minimum code bit length. - * @param node in: The node to begin searching at. - * @param codeLength out: Variable to hold the longest code bit length found. */ - static void minCodeLength( HuffmanNode const * const node, int &codeLength ); - - /** Increases a codeLength up to the longest Huffman code bit length found in the node or any of its children.
- * Set to Zero before calling to determine maximum code bit length. - * @param node in: The node to begin searching at. - * @param codeLength out: Variable to hold the longest code bit length found. */ - static void maxCodeLength( HuffmanNode const * const node, int &codeLength ); - - private: - - /** Perform initialization procedures common to all constructors. */ - void init(); - - }; // end class Huffman Codec. -} // end namespace skulltag - -#endif