X-Git-Url: https://git.llucax.com/z.facultad/75.06/jacu.git/blobdiff_plain/4ca9e227315aa797216a3eb0ea7d72e9db203143..c64d97e6f5f058648074b74ef4d8c3142826777f:/src/statichuff/statichuff.c diff --git a/src/statichuff/statichuff.c b/src/statichuff/statichuff.c index 28b932d..9934509 100644 --- a/src/statichuff/statichuff.c +++ b/src/statichuff/statichuff.c @@ -1,7 +1,30 @@ +/*---------------------------------------------------------------------------- + * jacu - Just Another Compression Utility + *---------------------------------------------------------------------------- + * This file is part of jacu. + * + * jacu is free software; you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation; either version 2 of the License, or (at your option) any later + * version. + * + * jacu is distributed in the hope that it will be useful, but WITHOUT ANY + * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + * + * You should have received a copy of the GNU General Public License along + * with jacu; if not, write to the Free Software Foundation, Inc., 59 Temple + * Place, Suite 330, Boston, MA 02111-1307 USA + *---------------------------------------------------------------------------- + */ + #include "statichuff.h" #include +#include +/** Coloca un bit en un buffer statico */ void putbit(char bit, char restart, char flush, VFILE *fp) { static unsigned long int bits_buffer = 0; @@ -34,6 +57,7 @@ void putbit(char bit, char restart, char flush, VFILE *fp) return; } +/** Realiza la copia de los datos de un nodo de huffman a otro */ void shuff_cpynode(SHUFFNODE *node1, SHUFFNODE *node2) { node1->symbol = node2->symbol; @@ -42,6 +66,7 @@ void shuff_cpynode(SHUFFNODE *node1, SHUFFNODE *node2) node1->rchild = node2->rchild; } +/** Realiza una comparacion de dos nodos de huffman */ int shuff_compnode(const void *node1, const void *node2) { if (((SHUFFNODE*)node1)->freq < ((SHUFFNODE*)node2)->freq) return 1; @@ -49,6 +74,23 @@ int shuff_compnode(const void *node1, const void *node2) return 0; } +/** Destruye un arbol de huffman recursivamente */ +void shuff_destroy_tree(SHUFFNODE *node) { + /* Si llegue a una hoja, destruyo y vuelvo */ + if (node->symbol < 256) { + free(node); + return; + } + else { + /* Desciendo por izq, luego por derecha y luego libero */ + shuff_destroy_tree(node->lchild); + shuff_destroy_tree(node->rchild); + free(node); + return; + } +} + +/** Reescala las frecuencias de huffman a la mitad */ int shuff_rescalefreq(t_freq *freqtable) { int i; @@ -63,26 +105,33 @@ int shuff_rescalefreq(t_freq *freqtable) return totalfreq; } +/** Escanea las frecuencias de un chunk de datos */ int shuff_scanfreq_chunk(HUFF_STATE *chunkshuff, char* chunk, int chunksize) { /* Locals */ int i = 0; unsigned char symbol = 0; - /* Contamos las frecuencias del chunk*/ - for (i = 0; i < chunksize; ++i) { - symbol = chunk[i]; - chunkshuff->freqtable[symbol] += 1; - chunkshuff->sumfreq += 1; + /* Contamos las frecuencias del chunk a menos que se use un canonico */ + if (!chunkshuff->canonic) { + for (i = 0; i < chunksize; ++i) { + symbol = chunk[i]; + chunkshuff->freqtable[symbol] += 1; + chunkshuff->sumfreq += 1; - /* Si llegue al tope de freq acumulada, halve em */ - if (chunkshuff->sumfreq == 14930352) - chunkshuff->sumfreq = shuff_rescalefreq(chunkshuff->freqtable); - } + /* Si llegue al tope de freq acumulada, halve em */ + if (chunkshuff->sumfreq == 14930352) + chunkshuff->sumfreq = shuff_rescalefreq(chunkshuff->freqtable); + } + } + + /* Dumpeamos el chunk en el temporal homero */ + fwrite(chunk,chunksize,1,chunkshuff->coderfp); return 1; } +/** Escanea las frecuencias de un archivo y genera el modelo */ int shuff_scanfreq(char *inputfile, t_freq *freqtable) { /* Locals */ @@ -112,6 +161,7 @@ int shuff_scanfreq(char *inputfile, t_freq *freqtable) return 1; } +/** Genera un input list que sera utilizada para generar el arbol */ SHUFFNODE *shuff_buildlist(t_freq *freqtable, int *nonzerofreqs) { int i,j = 0,nonzero = 0; @@ -135,6 +185,7 @@ SHUFFNODE *shuff_buildlist(t_freq *freqtable, int *nonzerofreqs) return inputlist; } +/** Genera el arbol de huffman en base a la tabla de frecuencias */ SHUFFNODE *shuff_buildtree(t_freq *ftable) { SHUFFNODE *lastsymbol; @@ -174,6 +225,7 @@ SHUFFNODE *shuff_buildtree(t_freq *ftable) return root; } +/** Imprime los codigos prefijos generados para los symbolos */ void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable) { int i,j; @@ -183,7 +235,7 @@ void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable) for (i = 0; i < 256; ++i) { if (codetable[i].codelength > 0) { auxcode = codetable[i].code; - printf("Symbol:%i Freq: %li Code:",i,freqtable[i]); + printf("Symbol:%i Freq: %lu Code:",i,freqtable[i]); for (j = codetable[i].codelength-1; j >= 0; --j) { auxcode = codetable[i].code; auxcode = auxcode >> j; @@ -195,6 +247,7 @@ void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable) } } +/** Inicializa la tabla de codigos prefijos */ void shuff_zerocodes(SHUFFCODE *table) { int i; @@ -206,6 +259,7 @@ void shuff_zerocodes(SHUFFCODE *table) } } +/** Genera la tabla de codigos prefijos en base al árbol de huffman */ void shuff_buildcodes(SHUFFCODE *table, SHUFFNODE *node, int level, int code) { if (node->symbol < 256) { @@ -221,6 +275,7 @@ void shuff_buildcodes(SHUFFCODE *table, SHUFFNODE *node, int level, int code) } } +/** Realiza la compresion / encoding efectivo de un archivo */ int shuff_encode_symbols(HUFF_STATE *shuff, SHUFFCODE *ctable) { FILE *fpsource; @@ -230,7 +285,11 @@ int shuff_encode_symbols(HUFF_STATE *shuff, SHUFFCODE *ctable) char bit; SHUFFCODE symbolcode; - /* Abrimos el file */ + /* Abrimos el source y el destino */ + if (shuff->coderfp != NULL) { + fclose(shuff->coderfp); /* close bychunk temp file */ + shuff->coderfp = NULL; + } if ((fpsource = fopen(shuff->sourcefile,"r")) == NULL) return 0; if ((fpdest = vfopen(shuff->targetfile,"w",shuff->volsize)) == NULL) return 0; @@ -262,13 +321,15 @@ int shuff_encode_symbols(HUFF_STATE *shuff, SHUFFCODE *ctable) return 1; } +/** Prepara las estructuras de datos necesarias para una compresion */ int shuff_encode_file(HUFF_STATE *shuff) { /* Locals */ SHUFFCODE *codetable = (SHUFFCODE*)malloc(sizeof(SHUFFCODE)*256); /* Veo si debo armar una freqtable o si esta preloaded */ - if (!shuff->preloadfreq) if (!shuff_scanfreq(shuff->sourcefile,shuff->freqtable)) return 0; + if ((!shuff->canonic) && (!shuff->bychunk)) + if (!shuff_scanfreq(shuff->sourcefile,shuff->freqtable)) return 0; /* Genero el arbol de huffman */ shuff->codetree = shuff_buildtree(shuff->freqtable); @@ -287,6 +348,7 @@ int shuff_encode_file(HUFF_STATE *shuff) return 1; } +/** Decodifica una serie de bits en un symbolo y lo devuelve */ SHUFFNODE *shuff_decode_symbols(SHUFFNODE *entrynode, unsigned long int buffer, int *bitsleft, unsigned short int *symbol) { @@ -304,6 +366,38 @@ SHUFFNODE *shuff_decode_symbols(SHUFFNODE *entrynode, unsigned long int buffer, else return shuff_decode_symbols(entrynode->rchild,buffer,bitsleft,symbol); } +/** Decodifica chunksize symbolos y los devuelve en un chunk de datos */ +int shuff_decode_chunk(HUFF_STATE *shuff, char *chunk, int chunksize, unsigned long int *decodedbytes) +{ + SHUFFNODE *currnode = shuff->codetree; + unsigned short int decoded_symbol; + *decodedbytes = 0; + + while (!vfeof(shuff->decoderfp) && (shuff->bytesleft > 0) && (*decodedbytes < chunksize)) { + + /* Leo un buffer de 32 bits si es que quedo vacio el anterior */ + if (shuff->bitsleft == 0) { + if (vfread(&(shuff->codebuffer),sizeof(unsigned long int),1,shuff->decoderfp) != 1) continue; + shuff->bitsleft = sizeof(unsigned long int) * 8; + } + + /* Proceso el buffer sacando simbolos till se me agote el buffer, file o chunk */ + while ((shuff->bitsleft > 0) && (shuff->bytesleft > 0) && (*decodedbytes < chunksize)) { + currnode = shuff_decode_symbols(currnode,shuff->codebuffer,&(shuff->bitsleft),&decoded_symbol); + /* Si obtuve un symbolo valido lo emito*/ + if (decoded_symbol != 256) { + chunk[(*decodedbytes)++] = decoded_symbol; + currnode = shuff->codetree; + --(shuff->bytesleft); + } + } + } + + if (shuff->bytesleft == 0) return 0; + else return 1; +} + +/** Realiza la descompresión de un archivo comprimido */ int shuff_decode_file(HUFF_STATE *shuff) { SHUFFNODE *currnode; @@ -312,7 +406,7 @@ int shuff_decode_file(HUFF_STATE *shuff) unsigned short int decoded_symbol; int bitsleft; - /* Levanto cuantos bytes decodeo y la freq table */ + /* Comienzo a decodificar, pues la tabla ya la levante en el decinit */ if ((fpdest = fopen(shuff->targetfile,"w")) == NULL) return 0; currnode = shuff->codetree; @@ -334,11 +428,13 @@ int shuff_decode_file(HUFF_STATE *shuff) } } + /* Close destination */ fclose(fpdest); return 1; } +/** Inicializa un descompresor de huffman */ HUFF_STATE *shuff_init_decoder(char *inputfile, char *outputfile) { /* Locals */ @@ -346,6 +442,8 @@ HUFF_STATE *shuff_init_decoder(char *inputfile, char *outputfile) shuff->freqtable = (t_freq*)malloc(sizeof(t_freq)*256); /* Init fields */ + shuff->codebuffer = 0; + shuff->bitsleft = 0; shuff->coderfp = NULL; shuff->targetfile = NULL; shuff->sourcefile = (char*)malloc(sizeof(char)*(strlen(inputfile)+1)); @@ -355,15 +453,17 @@ HUFF_STATE *shuff_init_decoder(char *inputfile, char *outputfile) strcpy(shuff->targetfile,outputfile); } - /* Levanto cuantos bytes decodeo y la freq table */ - if ((shuff->decoderfp = vfopen(shuff->sourcefile,"r",0)) == NULL) return 0; + /* Levanto cuantos bytes debo decodificar y la freqtable */ + if ((shuff->decoderfp = vfopen(shuff->sourcefile,"r",0)) == NULL) return NULL; vfread(&(shuff->bytesleft),sizeof(unsigned long int),1,shuff->decoderfp); - vfread(shuff->freqtable,sizeof(unsigned long int),256,shuff->decoderfp); + vfread(shuff->freqtable,sizeof(t_freq),256,shuff->decoderfp); + /* Armo el arbol de huffman que uso para decodificar */ shuff->codetree = shuff_buildtree(shuff->freqtable); return shuff; } +/** Inicializa compresor de huffman por archivo */ HUFF_STATE *shuff_init_encoder_byfile(char *inputfile, char *outputfile, long volsize) { /* Locals */ @@ -378,23 +478,24 @@ HUFF_STATE *shuff_init_encoder_byfile(char *inputfile, char *outputfile, long vo strcpy(fshuff->sourcefile,inputfile); strcpy(fshuff->targetfile,outputfile); fshuff->volsize = volsize; - fshuff->preloadfreq = 0; + fshuff->bychunk = 0; + fshuff->canonic = 0; fshuff->freqtable = (t_freq*)malloc(sizeof(t_freq)*256); for (i = 0; i < 256; ++i) fshuff->freqtable[i] = 0; fshuff->sumfreq = 0; - fshuff->bytesleft = 0; fshuff->codetree = NULL; return fshuff; } +/** Inicializa compresor de huffman de a chunks */ HUFF_STATE *shuff_init_encoder_bychunk(char *outputfile, long volsize) { /* Locals */ HUFF_STATE *cshuff = (HUFF_STATE*)malloc(sizeof(HUFF_STATE)); int i; - /* Inicializo la estructura para trabajar con Huff Static by Chunks */ + /* Inicializo la estructura para trabajar con Huff Static by Chunks */ cshuff->decoderfp = NULL; cshuff->sourcefile = (char*)malloc(sizeof(char)*(strlen(outputfile)+2)); cshuff->targetfile = (char*)malloc(sizeof(char)*(strlen(outputfile)+1)); @@ -402,12 +503,12 @@ HUFF_STATE *shuff_init_encoder_bychunk(char *outputfile, long volsize) strcpy(cshuff->sourcefile,outputfile); strcat(cshuff->sourcefile,"~"); cshuff->volsize = volsize; - cshuff->preloadfreq = 1; + cshuff->bychunk = 1; + cshuff->canonic = 0; cshuff->freqtable = (t_freq*)malloc(sizeof(t_freq)*256); for (i = 0; i < 256; ++i) cshuff->freqtable[i] = 0; - cshuff->sumfreq = 0; - cshuff->bytesleft = 0; - cshuff->codetree = NULL; + cshuff->sumfreq = 0; + cshuff->codetree = NULL; /* Abrimos un archivo temporal para ir tirando los chunks */ if ((cshuff->coderfp = fopen(cshuff->sourcefile,"w")) == NULL) return NULL; @@ -415,25 +516,70 @@ HUFF_STATE *shuff_init_encoder_bychunk(char *outputfile, long volsize) return cshuff; } +/** Carga un modelo estadistico para huffman */ +int shuff_loadmodel(HUFF_STATE *shuff, char *modelfile) { + + FILE *fp; + + if ((shuff) && (shuff->freqtable) && (modelfile)) { + /* Cargo el modelo de disco */ + if ((fp = fopen(modelfile,"r")) == NULL) return 0; + if (fread(shuff->freqtable,sizeof(t_freq),256,fp) != 256) return 0; + shuff->canonic = 1; + if (fp) fclose(fp); + return 1; + } + return 0; +} + +/** Graba un modelo estadístico de huffman */ +int shuff_savemodel(HUFF_STATE *shuff) { + + FILE *fp; + char *auxfilename; + char *stopchar; + + if ((shuff) && (shuff->targetfile) && (shuff->freqtable)) { + /* Preparo el nombre del archivo con la tabla */ + auxfilename = (char*)malloc(strlen(shuff->targetfile)+1); + stopchar = strrchr(shuff->targetfile,'.'); + strncpy(auxfilename,shuff->targetfile,stopchar - shuff->targetfile); + auxfilename[stopchar - shuff->targetfile] = 0; + strcat(auxfilename,".ftb"); + + /* Lo creamos y dumpeamos la tabla de frecuencias (modelo) */ + if ((fp = fopen(auxfilename,"w")) == NULL) return 0; + fwrite(shuff->freqtable,sizeof(t_freq),256,fp); + if (fp) fclose(fp); + + return 1; + } + return 0; +} + +/** Desinicializa un compresor de huffman */ void shuff_deinit_encoder(HUFF_STATE *shuff) { /* Libero mallocs y cierro archivos */ - free(shuff->freqtable); - free(shuff->sourcefile); - free(shuff->targetfile); - if (shuff->coderfp != NULL) fclose(shuff->coderfp); - if (shuff->decoderfp != NULL) vfclose(shuff->decoderfp); + if (shuff->freqtable) free(shuff->freqtable); + if (shuff->coderfp) fclose(shuff->coderfp); + if (shuff->bychunk) unlink(shuff->sourcefile); + if (shuff->sourcefile) free(shuff->sourcefile); + if (shuff->targetfile) free(shuff->targetfile); /* Destruyo recursivamente el arbol de codigos */ + if (shuff->codetree) shuff_destroy_tree(shuff->codetree); } +/** Desinicializa un descompresor de huffman */ void shuff_deinit_decoder(HUFF_STATE *shuff) { /* Libero mallocs y cierro archivos */ - free(shuff->freqtable); - free(shuff->sourcefile); + if (shuff->freqtable) free(shuff->freqtable); + if (shuff->sourcefile != NULL) free(shuff->sourcefile); if (shuff->targetfile != NULL) free(shuff->targetfile); if (shuff->decoderfp != NULL) vfclose(shuff->decoderfp); /* Destruyo recursivamente el arbol de codigos */ + if (shuff->codetree) shuff_destroy_tree(shuff->codetree); }