Test de Calgary sobre JACU vs GZIP vs BZIP2 done, me falta el pic en mi maquina que...

[z.facultad/75.06/jacu.git] / src / statichuff / statichuff.c

diff --git a/src/statichuff/statichuff.c b/src/statichuff/statichuff.c
index e1dfe3537424cc2da4d68c18e5b73de28cbb6688..f339ef0558b67c93b54905a7514f223516a343a6 100644 (file)
--- a/src/statichuff/statichuff.c
+++ b/src/statichuff/statichuff.c
@@ -1,17 +1,18 @@
 
 #include "statichuff.h"
 #include <stdlib.h>
 
 #include "statichuff.h"
 #include <stdlib.h>

+#include <string.h>

 
 

-void putbit(char bit, char restart, char flush, FILE *fp)
+/** Coloca un bit en un buffer statico */
+void putbit(char bit, char restart, char flush, VFILE *fp)

 {
        static unsigned long int bits_buffer = 0;
 {
        static unsigned long int bits_buffer = 0;

-       static unsigned char bits_used = 0;
-       int i;
+       static unsigned char bits_used = 0;     

 
        /* me obligan a emitir el output */
        if ((flush == 1) && (bits_used > 0)) {
                bits_buffer = bits_buffer << ((sizeof(unsigned long int)*8) - bits_used);
 
        /* me obligan a emitir el output */
        if ((flush == 1) && (bits_used > 0)) {
                bits_buffer = bits_buffer << ((sizeof(unsigned long int)*8) - bits_used);

-               fwrite(&bits_buffer,sizeof(unsigned long int),1,fp);
+               vfwrite(&bits_buffer,sizeof(unsigned long int),1,fp);

                bits_buffer = 0;
                bits_used = 0;
                return;
                bits_buffer = 0;
                bits_used = 0;
                return;


@@ -28,13 +29,14 @@ void putbit(char bit, char restart, char flush, FILE *fp)
        
        /* lleno el buffer, escribo */
        if (bits_used == 32) {
        
        /* lleno el buffer, escribo */
        if (bits_used == 32) {

-               fwrite(&bits_buffer,sizeof(unsigned long int),1,fp);
+               vfwrite(&bits_buffer,sizeof(unsigned long int),1,fp);

                bits_buffer = 0;
                bits_used = 0;
        }       
        return;
 }
 
                bits_buffer = 0;
                bits_used = 0;
        }       
        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;
 void shuff_cpynode(SHUFFNODE *node1, SHUFFNODE *node2)
 {
        node1->symbol = node2->symbol;


@@ -43,28 +45,72 @@ void shuff_cpynode(SHUFFNODE *node1, SHUFFNODE *node2)
        node1->rchild = node2->rchild;  
 }
 
        node1->rchild = node2->rchild;  
 }
 

-int shuff_compnode(SHUFFNODE *node1, SHUFFNODE *node2)
+/** Realiza una comparacion de dos nodos de huffman */
+int shuff_compnode(const void *node1, const void *node2)

 {      
 {      

-       if (node1->freq < node2->freq) return 1;
-       if (node1->freq > node2->freq) return -1;
+       if (((SHUFFNODE*)node1)->freq < ((SHUFFNODE*)node2)->freq) return 1;
+       if (((SHUFFNODE*)node1)->freq > ((SHUFFNODE*)node2)->freq) return -1;

        return 0;
 }
 
        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;
        t_freq totalfreq = 0;
        
        /* Divido por la mitad las frecuencias, asegurando de no perder */
 int shuff_rescalefreq(t_freq *freqtable)
 { 
        int i;
        t_freq totalfreq = 0;
        
        /* Divido por la mitad las frecuencias, asegurando de no perder */

-       /* frequencias en 1, por ello le sumo 1 antes de partir */

        for (i = 0; i < 256; i++) {             
        for (i = 0; i < 256; i++) {             

-               freqtable[i] = (freqtable[i] << 2) | 1;
+               freqtable[i] = (freqtable[i] >> 2) | 1;

                totalfreq += freqtable[i];
        }
        
        return totalfreq;
 }
 
                totalfreq += freqtable[i];
        }
        
        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 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);
+               }
+       }
+       
+       /* 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 */    
 int shuff_scanfreq(char *inputfile, t_freq *freqtable)
 {
        /* Locals */    


@@ -76,7 +122,7 @@ int shuff_scanfreq(char *inputfile, t_freq *freqtable)
        for (i = 0; i < 256; ++i) freqtable[i] = 0;
                
        /* Abrimos el file */
        for (i = 0; i < 256; ++i) freqtable[i] = 0;
                
        /* Abrimos el file */

-       if ((fp = fopen(inputfile,"rb")) == NULL) return 0;
+       if ((fp = fopen(inputfile,"r")) == NULL) return 0;

        while (!feof(fp)) {             
                /* Contamos las frecuencias */          
                symbol = fgetc(fp);
        while (!feof(fp)) {             
                /* Contamos las frecuencias */          
                symbol = fgetc(fp);


@@ -91,9 +137,10 @@ int shuff_scanfreq(char *inputfile, t_freq *freqtable)
        }
        
        fclose(fp);
        }
        
        fclose(fp);

-       return 1;       
+       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;        
 SHUFFNODE *shuff_buildlist(t_freq *freqtable, int *nonzerofreqs)
 {
        int i,j = 0,nonzero = 0;        


@@ -117,15 +164,21 @@ SHUFFNODE *shuff_buildlist(t_freq *freqtable, int *nonzerofreqs)
        return inputlist;
 }
 
        return inputlist;
 }
 

-SHUFFNODE *shuff_buildtree(SHUFFNODE *list, int listcount)
+/** Genera el arbol de huffman en base a la tabla de frecuencias */
+SHUFFNODE *shuff_buildtree(t_freq *ftable)

 {
 {

-       SHUFFNODE *lastsymbol = list+(listcount-1);
-       SHUFFNODE *node1,*node2,*fictnode;
+       SHUFFNODE *lastsymbol;
+       SHUFFNODE *node1,*node2,*root;
+       SHUFFNODE *inputlist;
+       int freqcount = 0;

 
 

-       /* Ordenamos inicialmente la inputlist para tomar las dos freqs min */
-       while (lastsymbol > list) {             
+       /* Genero la input list en base a la cual genera el arbol */
+       inputlist = shuff_buildlist(ftable, &freqcount);        
+       lastsymbol = inputlist+(freqcount-1);
+       
+       while (lastsymbol > inputlist) {                

                /* Ordeno la lista por frecuencia descendente */
                /* Ordeno la lista por frecuencia descendente */

-               qsort(list,listcount,sizeof(SHUFFNODE),shuff_compnode);                         
+               qsort(inputlist,freqcount,sizeof(SHUFFNODE),shuff_compnode);                            

                /* Tomo los ultimos dos elementos, generando dos nodos del arbol */
                node1 = (SHUFFNODE*)malloc(sizeof(SHUFFNODE));
                node2 = (SHUFFNODE*)malloc(sizeof(SHUFFNODE));
                /* Tomo los ultimos dos elementos, generando dos nodos del arbol */
                node1 = (SHUFFNODE*)malloc(sizeof(SHUFFNODE));
                node2 = (SHUFFNODE*)malloc(sizeof(SHUFFNODE));


@@ -137,13 +190,21 @@ SHUFFNODE *shuff_buildtree(SHUFFNODE *list, int listcount)
                lastsymbol->freq = node1->freq + node2->freq;
                lastsymbol->lchild = node1;
                lastsymbol->rchild = node2;
                lastsymbol->freq = node1->freq + node2->freq;
                lastsymbol->lchild = node1;
                lastsymbol->rchild = node2;

-               --listcount;
+               --freqcount;

        }
        }

-               
+       
+       /* Copio la raiz para poder liberar la lista sin perderla */
+       root = (SHUFFNODE*)malloc(sizeof(SHUFFNODE));
+       shuff_cpynode(root,lastsymbol);
+       
+       /* Free up mem */
+       free(inputlist);
+       

        /* Devuelvo el puntero a la raiz del arbol de huffman */
        /* Devuelvo el puntero a la raiz del arbol de huffman */

-       return lastsymbol;
+       return root;

 }
 
 }
 

+/** Imprime los codigos prefijos generados para los symbolos */

 void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable)
 {
        int i,j;
 void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable)
 {
        int i,j;


@@ -153,7 +214,7 @@ void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable)
        for (i = 0; i < 256; ++i) {
                if (codetable[i].codelength > 0) {
                        auxcode = codetable[i].code;                    
        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;
                        for (j = codetable[i].codelength-1; j >= 0; --j) {
                                auxcode = codetable[i].code;                    
                                auxcode = auxcode >> j;


@@ -165,6 +226,7 @@ void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable)
        }
 }
 
        }
 }
 

+/** Inicializa la tabla de codigos prefijos */

 void shuff_zerocodes(SHUFFCODE *table)
 {
        int i;
 void shuff_zerocodes(SHUFFCODE *table)
 {
        int i;


@@ -176,6 +238,7 @@ 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) {
 void shuff_buildcodes(SHUFFCODE *table, SHUFFNODE *node, int level, int code)
 {
        if (node->symbol < 256) {


@@ -191,25 +254,29 @@ void shuff_buildcodes(SHUFFCODE *table, SHUFFNODE *node, int level, int code)
        }
 }
 
        }
 }
 

-
-
-int shuff_encode_symbols(t_freq *ftable, SHUFFCODE *ctable, char* inputfile, char *outputfile) {
-
-       FILE *fpsource,*fpdest;
+/** Realiza la compresion / encoding efectivo de un archivo */
+int shuff_encode_symbols(HUFF_STATE *shuff, SHUFFCODE *ctable)
+{
+       FILE *fpsource;
+       VFILE *fpdest;

        int symbol,i;
        unsigned long int sourcesize;
        char bit;
        SHUFFCODE symbolcode;
                
        int symbol,i;
        unsigned long int sourcesize;
        char bit;
        SHUFFCODE symbolcode;
                

-       /* Abrimos el file */
-       if ((fpsource = fopen(inputfile,"rb")) == NULL) return 0;
-       if ((fpdest = fopen(outputfile,"wb")) == NULL) return 0;
+       /* 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;

                
        /* Guardamos el size el archivo original e inputlist como header */
        fseek(fpsource,0,SEEK_END);
        sourcesize = ftell(fpsource);
                
        /* Guardamos el size el archivo original e inputlist como header */
        fseek(fpsource,0,SEEK_END);
        sourcesize = ftell(fpsource);

-       fwrite(&sourcesize,sizeof(unsigned long int),1,fpdest);
-       fwrite(ftable,sizeof(t_freq),256,fpdest);
+       vfwrite(&sourcesize,sizeof(unsigned long int),1,fpdest);
+       vfwrite(shuff->freqtable,sizeof(t_freq),256,fpdest);

        
        /* Encodeo */
        fseek(fpsource,0,SEEK_SET);
        
        /* Encodeo */
        fseek(fpsource,0,SEEK_SET);


@@ -229,68 +296,269 @@ int shuff_encode_symbols(t_freq *ftable, SHUFFCODE *ctable, char* inputfile, cha
        /* Hacemos un flush de lo que haya quedado en el buffer de salida */
        putbit(0,0,1,fpdest);
        fclose(fpsource);
        /* Hacemos un flush de lo que haya quedado en el buffer de salida */
        putbit(0,0,1,fpdest);
        fclose(fpsource);

-       fclose(fpdest);
+       vfclose(fpdest);

        return 1;       
 }
 
        return 1;       
 }
 

-int shuff_encode_file(char *inputfile, char *outputfile)
+/** Prepara las estructuras de datos necesarias para una compresion */
+int shuff_encode_file(HUFF_STATE *shuff)

 {
 {

-       /* Locals */
-       t_freq *freqtable = (t_freq*)malloc(sizeof(t_freq)*256);
-       SHUFFNODE *inputlist;
-       SHUFFNODE *codetree;
+       /* Locals */            

        SHUFFCODE *codetable = (SHUFFCODE*)malloc(sizeof(SHUFFCODE)*256);
        SHUFFCODE *codetable = (SHUFFCODE*)malloc(sizeof(SHUFFCODE)*256);

-       int freqcount = 0,i;

        
        

-       /* Armamos la tabla de frecuencias */
-       if (!shuff_scanfreq(inputfile,freqtable)) return -1;
+       /* Veo si debo armar una freqtable o si esta preloaded */
+       if ((!shuff->canonic) && (!shuff->bychunk)) 
+               if (!shuff_scanfreq(shuff->sourcefile,shuff->freqtable)) return 0;

        
        

-       /* Armo el input list y genero el arbol de huffman */
-       inputlist = shuff_buildlist(freqtable, &freqcount);
-       codetree = shuff_buildtree(inputlist,freqcount);
+       /* Genero el arbol de huffman */
+       shuff->codetree = shuff_buildtree(shuff->freqtable);

 
        /* Armo la tabla de codigos prefijos para el encoder */
        shuff_zerocodes(codetable);
 
        /* Armo la tabla de codigos prefijos para el encoder */
        shuff_zerocodes(codetable);

-       shuff_buildcodes(codetable,codetree,0,0);
-       shuff_printcodes(codetable,freqtable);
+       shuff_buildcodes(codetable,shuff->codetree,0,0);
+       /*shuff_printcodes(codetable,shuff->freqtable);*/

 
        /* Encodeo byte per byte */
 
        /* Encodeo byte per byte */

-       shuff_encode_symbols(freqtable,codetable,inputfile,outputfile);
+       shuff_encode_symbols(shuff,codetable);
+       
+       /* Free up memory baby yeah */  
+       free(codetable);
+       
+       return 1;

 }
 
 }
 

-int shuff_decode(char *inputfile, char *outputfile)
+/** 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)

 {
 {

-       SHUFFNODE *inputlist;
-       SHUFFNODE *codetree;
-       t_freq *ftable = (t_freq*)malloc(sizeof(t_freq)*256);
-       unsigned long int bytesleft;
-       FILE *fpsource;
-       FILE *fpdest;
-       int i,freqcount = 0;
-       
-       /* Levanto cuantos bytes decodeo y la freq table */
-       if ((fpsource = fopen(inputfile,"rb")) == NULL) return 0;
-       if ((fpdest = fopen(outputfile,"wb")) == NULL) return 0;
-       fread(&bytesleft,sizeof(unsigned long int),1,fpsource);
-       fread(ftable,sizeof(unsigned long int),256,fpsource);
-       inputlist = shuff_buildlist(ftable, &freqcount);
-       codetree = shuff_buildtree(inputlist,freqcount);
+       char bit = 0;

                
                

-       fclose(fpsource);
-       fclose(fpdest);
+       /* Levanto el symbolo y si es uno valido, devuelvo */
+       *symbol = entrynode->symbol;
+       if (*symbol != 256) return entrynode;           
+       if (*bitsleft == 0) return entrynode;
+               
+       /* Obtengo otro bit a procesar y me muevo en el arbol */
+       bit = (buffer >> ((*bitsleft)-1)) & 1;  
+       --(*bitsleft);
+       if (bit == 0) return shuff_decode_symbols(entrynode->lchild,buffer,bitsleft,symbol);
+       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;

 }
 
 }
 

-int main(int argc, char* argv[])
+/** Realiza la descompresión de un archivo comprimido */
+int shuff_decode_file(HUFF_STATE *shuff)

 {      
 {      

-       if (argc == 1) return -1;
+       SHUFFNODE *currnode;    
+       unsigned long int codebuffer;   
+       FILE *fpdest;
+       unsigned short int decoded_symbol;
+       int bitsleft;   
+       
+       /* Comienzo a decodificar, pues la tabla ya la levante en el decinit */
+       if ((fpdest = fopen(shuff->targetfile,"w")) == NULL) return 0;  
+       currnode = shuff->codetree;
+       
+       while (!vfeof(shuff->decoderfp) && (shuff->bytesleft > 0)) {

                
                

-       /* Comprimo */
-       shuff_encode_file(argv[1],"output.shf");        
+               /* Leo un buffer de 32 bits */
+               if (vfread(&codebuffer,sizeof(unsigned long int),1,shuff->decoderfp) != 1) continue;
+               bitsleft = sizeof(unsigned long int) * 8;
+               
+               /* Proceso el buffer sacando simbolos hasta que se me agote */
+               while ((bitsleft > 0) && (shuff->bytesleft > 0)) {      
+                       currnode = shuff_decode_symbols(currnode,codebuffer,&bitsleft,&decoded_symbol);
+                       /* Si obtuve un symbolo valido lo emito*/
+                       if (decoded_symbol != 256) {
+                               fputc(decoded_symbol,fpdest);
+                               currnode = shuff->codetree;
+                               --(shuff->bytesleft);
+                       }                                               
+               }               
+       }
+                       
+       /* Close destination */
+       fclose(fpdest); 
+       
+       return 1;
+}

 
 

-       /* Decodeo */
-       shuff_decode("output.shf","decoded.dat");
+/** Inicializa un descompresor de huffman */
+HUFF_STATE *shuff_init_decoder(char *inputfile, char *outputfile)
+{
+       /* Locals */
+       HUFF_STATE *shuff = (HUFF_STATE*)malloc(sizeof(HUFF_STATE));                    
+       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));
+       strcpy(shuff->sourcefile,inputfile);
+       if (outputfile != NULL) {
+               shuff->targetfile = (char*)malloc(sizeof(char)*(strlen(outputfile)+1));
+               strcpy(shuff->targetfile,outputfile);
+       }       
+       
+       /* 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(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 */
+       HUFF_STATE *fshuff = (HUFF_STATE*)malloc(sizeof(HUFF_STATE));                   
+       int i;
+       
+       /* Inicializo la estructura para trabajar con Huff Static by File */
+       fshuff->coderfp = NULL; 
+       fshuff->decoderfp = NULL;       
+       fshuff->sourcefile = (char*)malloc(sizeof(char)*(strlen(inputfile)+1));
+       fshuff->targetfile = (char*)malloc(sizeof(char)*(strlen(outputfile)+1));
+       strcpy(fshuff->sourcefile,inputfile);   
+       strcpy(fshuff->targetfile,outputfile);
+       fshuff->volsize = volsize;
+       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->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 */          
+       cshuff->decoderfp = NULL;
+       cshuff->sourcefile = (char*)malloc(sizeof(char)*(strlen(outputfile)+2));
+       cshuff->targetfile = (char*)malloc(sizeof(char)*(strlen(outputfile)+1));
+       strcpy(cshuff->targetfile,outputfile);  
+       strcpy(cshuff->sourcefile,outputfile);
+       strcat(cshuff->sourcefile,"~"); 
+       cshuff->volsize = volsize;
+       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->codetree = NULL;        
+       
+       /* Abrimos un archivo temporal para ir tirando los chunks */    
+       if ((cshuff->coderfp = fopen(cshuff->sourcefile,"w")) == NULL) return NULL;     
+
+       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;
 }
        return 0;
 }

+
+/** Desinicializa un compresor de huffman */
+void shuff_deinit_encoder(HUFF_STATE *shuff)
+{
+       /* Libero mallocs y cierro archivos */
+       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 */  
+       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);
+}