huffman/huffman.cpp@927f4b8ef6f7
huffman/huffman.cpp
Thu, 28 Jan 2021 11:39:48 +0200
- author
- Teemu Piippo <teemu@hecknology.net>
- date
- Thu, 28 Jan 2021 11:39:48 +0200
- branch
- protocol5
- changeset 199
- 927f4b8ef6f7
- parent 76
- 6de6d9a64ebd
- permissions
- -rw-r--r--
merged with default
/* * Replacement for older Skulltag Launcher Protocol's huffman.cpp * * 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. */ // required for atexit() #include <stdlib.h> #include <stdio.h> #include "huffman.h" #include "huffcodec.h" // #include "i_system.h" using namespace skulltag; // Global Variables /** Reference to the HuffmanCodec Object that will perform the encoding and decoding. */ static HuffmanCodec * __codec = NULL; // Function Implementation /** Creates and intitializes a HuffmanCodec Object. <br> * Also arranges for HUFFMAN_Destruct() to be called upon termination. */ void HUFFMAN_Construct(){ // The exact structure description of a Huffman tree static unsigned char const compatible_huffman_tree[] = { 0, 0, 0, 1,128, 0, 0, 0, 3, 38, 34, 2, 1, 80, 3,110, 144, 67, 0, 2, 1, 74, 3,243,142, 37, 2, 3,124, 58,182, 0, 0, 1, 36, 0, 3,221,131, 3,245,163, 1, 35, 3,113, 85, 0, 1, 41, 1, 77, 3,199,130, 0, 1,206, 3,185,153, 3, 70,118, 0, 3, 3, 5, 0, 0, 1, 24, 0, 2, 3,198,190, 63, 2, 3, 139,186, 75, 0, 1, 44, 2, 3,240,218, 56, 3, 40, 39, 0, 0, 2, 2, 3,244,247, 81, 65, 0, 3, 9,125, 3, 68, 60, 0, 0, 1, 25, 3,191,138, 3, 86, 17, 0, 1, 23, 3,220,178, 2, 3, 165,194, 14, 1, 0, 2, 2, 0, 0, 2, 1,208, 3,150,157,181, 1,222, 2, 3,216,230,211, 0, 2, 2, 3,252,141, 10, 42, 0, 2, 3,134,135,104, 1,103, 3,187,225, 95, 32, 0, 0, 0, 0, 0, 0, 1, 57, 1, 61, 3,183,237, 0, 0, 3,233,234, 3,246, 203, 2, 3,250,147, 79, 1,129, 0, 1, 7, 3,143,136, 1, 20, 3,179,148, 0, 0, 0, 3, 28,106, 3,101, 87, 1, 66, 0, 3, 180,219, 3,227,241, 0, 1, 26, 1,251, 3,229,214, 3, 54, 69, 0, 0, 0, 0, 0, 3,231,212, 3,156,176, 3, 93, 83, 0, 3, 96,253, 3, 30, 13, 0, 0, 2, 3,175,254, 94, 3,159, 27, 2, 1, 8, 3,204,226, 78, 0, 0, 0, 3,107, 88, 1, 31, 3,137, 169, 2, 2, 3,215,145, 6, 4, 1,127, 0, 1, 99, 3,209,217, 0, 3,213,238, 3,177,170, 1,132, 0, 0, 0, 2, 3, 22, 12, 114, 2, 2, 3,158,197, 97, 45, 0, 1, 46, 1,112, 3,174,249, 0, 3,224,102, 2, 3,171,151,193, 0, 0, 0, 3, 15, 16, 3, 2,168, 1, 49, 3, 91,146, 0, 1, 48, 3,173, 29, 0, 3, 19, 126, 3, 92,242, 0, 0, 0, 0, 0, 0, 3,205,192, 2, 3,235, 149,255, 2, 3,223,184,248, 0, 0, 3,108,236, 3,111, 90, 2, 3,117,115, 71, 0, 0, 3, 11, 50, 0, 3,188,119, 1,122, 3, 167,162, 1,160, 1,133, 3,123, 21, 0, 0, 2, 1, 59, 2, 3, 155,154, 98, 43, 0, 3, 76, 51, 2, 3,201,116, 72, 2, 0, 2, 3,109,100,121, 2, 3,195,232, 18, 1, 0, 2, 0, 1,164, 2, 3,120,189, 73, 0, 1,196, 3,239,210, 3, 64, 62, 89, 0, 0, 1, 33, 2, 3,228,161, 55, 2, 3, 84,152, 47, 0, 0, 2, 3, 207,172,140, 3, 82,166, 0, 3, 53,105, 1, 52, 3,202,200 }; // create a HuffmanCodec that is compatible with the previous implementation. __codec = new HuffmanCodec( compatible_huffman_tree, sizeof compatible_huffman_tree ); // set up the HuffmanCodec to perform in a backwards compatible fashion. __codec->reversedBytes( true ); __codec->allowExpansion( false ); // request that the destruct function be called upon exit. // atterm( HUFFMAN_Destruct ); atexit( HUFFMAN_Destruct ); } /** Releases resources allocated by the HuffmanCodec. */ void HUFFMAN_Destruct(){ delete __codec; __codec = NULL; } /** Applies Huffman encoding to a block of data. */ void HUFFMAN_Encode( /** in: Pointer to start of data that is to be encoded. */ unsigned char const * const inputBuffer, /** out: Pointer to destination buffer where encoded data will be stored. */ unsigned char * const outputBuffer, /** in: Number of chars to read from inputBuffer. */ int const &inputBufferSize, /**< in+out: Max chars to write into outputBuffer. <br> * Upon return holds the number of chars stored or 0 if an error occurs. */ int * outputBufferSize ){ int bytesWritten = __codec->encode( inputBuffer, outputBuffer, inputBufferSize, *outputBufferSize ); // expansion occured -- provide backwards compatibility if ( bytesWritten < 0 ){ // check buffer sizes if ( *outputBufferSize < (inputBufferSize + 1) ){ // outputBuffer too small, return "no bytes written" *outputBufferSize = 0; return; } // perform the unencoded copy for ( int i = 0; i < inputBufferSize; i++ ) outputBuffer[i+1] = inputBuffer[i]; // supply the "unencoded" signal and bytesWritten outputBuffer[0] = 0xff; *outputBufferSize = inputBufferSize + 1; } else { // assign the bytesWritten return value *outputBufferSize = bytesWritten; } } // end function HUFFMAN_Encode /** Decodes a block of data that is Huffman encoded. */ void HUFFMAN_Decode( unsigned char const * const inputBuffer, /**< in: Pointer to start of data that is to be decoded. */ unsigned char * const outputBuffer, /**< out: Pointer to destination buffer where decoded data will be stored. */ int const &inputBufferSize, /**< in: Number of chars to read from inputBuffer. */ int *outputBufferSize /**< in+out: Max chars to write into outputBuffer. Upon return holds the number of chars stored or 0 if an error occurs. */ ){ // check for "unencoded" signal & provide backwards compatibility if ((inputBufferSize > 0) && ((inputBuffer[0]&0xff) == 0xff)){ // check buffer sizes if ( *outputBufferSize < (inputBufferSize - 1) ){ // outputBuffer too small, return "no bytes written" *outputBufferSize = 0; return; } // perform the unencoded copy for ( int i = 1; i < inputBufferSize; i++ ) outputBuffer[i-1] = inputBuffer[i]; // supply the bytesWritten *outputBufferSize = inputBufferSize - 1; } else { // decode the data *outputBufferSize = __codec->decode( inputBuffer, outputBuffer, inputBufferSize, *outputBufferSize ); } } // end function HUFFMAN_Decode
