Listo Huffman, Encoding y Decoding con Codigos de 32 bits maximo. Tambien arme el...

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

diff --git a/src/statichuff/statichuff.c b/src/statichuff/statichuff.c
index e1dfe3537424cc2da4d68c18e5b73de28cbb6688..e608bb20f27cd146805293be653d2231cbbc8cd7 100644 (file)
--- a/src/statichuff/statichuff.c
+++ b/src/statichuff/statichuff.c
@@ -5,8 +5,7 @@
 void putbit(char bit, char restart, char flush, FILE *fp)
 {
        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)) {
@@ -120,7 +119,7 @@ SHUFFNODE *shuff_buildlist(t_freq *freqtable, int *nonzerofreqs)
 SHUFFNODE *shuff_buildtree(SHUFFNODE *list, int listcount)
 {
        SHUFFNODE *lastsymbol = list+(listcount-1);
-       SHUFFNODE *node1,*node2,*fictnode;
+       SHUFFNODE *node1,*node2;
 
        /* Ordenamos inicialmente la inputlist para tomar las dos freqs min */
        while (lastsymbol > list) {             
@@ -240,10 +239,10 @@ int shuff_encode_file(char *inputfile, char *outputfile)
        SHUFFNODE *inputlist;
        SHUFFNODE *codetree;
        SHUFFCODE *codetable = (SHUFFCODE*)malloc(sizeof(SHUFFCODE)*256);
-       int freqcount = 0,i;
+       int freqcount = 0;
        
        /* Armamos la tabla de frecuencias */
-       if (!shuff_scanfreq(inputfile,freqtable)) return -1;
+       if (!shuff_scanfreq(inputfile,freqtable)) return 0;
        
        /* Armo el input list y genero el arbol de huffman */
        inputlist = shuff_buildlist(freqtable, &freqcount);
@@ -252,45 +251,116 @@ int shuff_encode_file(char *inputfile, char *outputfile)
        /* Armo la tabla de codigos prefijos para el encoder */
        shuff_zerocodes(codetable);
        shuff_buildcodes(codetable,codetree,0,0);
-       shuff_printcodes(codetable,freqtable);
+       /*shuff_printcodes(codetable,freqtable);*/
 
        /* Encodeo byte per byte */
        shuff_encode_symbols(freqtable,codetable,inputfile,outputfile);
+       
+       return 1;
 }
 
-int shuff_decode(char *inputfile, char *outputfile)
+SHUFFNODE *shuff_decode_symbols(SHUFFNODE *entrynode, unsigned long int buffer, 
+                                                        int *bitsleft, unsigned short int *symbol)
+{
+       char bit = 0;
+               
+       /* 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);
+}
+
+int shuff_decode_file(char *inputfile, char *outputfile)
 {
        SHUFFNODE *inputlist;
-       SHUFFNODE *codetree;
+       SHUFFNODE *codetree,*currnode;
        t_freq *ftable = (t_freq*)malloc(sizeof(t_freq)*256);
-       unsigned long int bytesleft;
+       unsigned long int bytesleft,codebuffer;
        FILE *fpsource;
        FILE *fpdest;
-       int i,freqcount = 0;
+       unsigned short int decoded_symbol;
+       int bitsleft,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);
+       fread(ftable,sizeof(unsigned long int),256,fpsource);   
        inputlist = shuff_buildlist(ftable, &freqcount);
        codetree = shuff_buildtree(inputlist,freqcount);
+       currnode = codetree;
+       
+       while (!feof(fpsource) && (bytesleft > 0)) {
+               
+               /* Leo un buffer de 32 bits */
+               if (fread(&codebuffer,sizeof(unsigned long int),1,fpsource) != 1) continue;
+               bitsleft = sizeof(unsigned long int) * 8;
+               
+               /* Proceso el buffer sacando simbolos hasta que se me agote */
+               while ((bitsleft > 0) && (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 = codetree;
+                               --bytesleft;                            
+                       }                                               
+               }               
+       }
                
        fclose(fpsource);
        fclose(fpdest);
        
-       
+       return 1;
 }
 
 int main(int argc, char* argv[])
 {      
-       if (argc == 1) return -1;
+       int cflag = 0;
+       int dflag = 0;
+       int tflag = 0;
+       long int volumesize = 0;
+       int ch;
+                       
+       while ((ch = getopt(argc, argv, "cdt:")) != -1) { 
+                
+               switch (ch) { 
+                       case 'c': cflag = 1; 
+                                         break;
+                       
+                       case 'd': dflag = 1; 
+                                         break; 
+                       
+                       case 't': tflag = 1; 
+                                         volumesize = atoi(optarg);                                      
+                                         break; 
+                       
+                       default: fprintf(stderr, "Usage: %s [-cdt] sourcefile targetfile\n", argv[0]); 
+                                        return(2);
+               }
+       }
                
-       /* Comprimo */
-       shuff_encode_file(argv[1],"output.shf");        
-
-       /* Decodeo */
-       shuff_decode("output.shf","decoded.dat");
+       if ( (argc == 1) || (cflag & dflag) || !(cflag | dflag) || ((argc - optind) < 2) ) {
+               fprintf(stderr, "Usage: %s [-cdt] sourcefile targetfile\n", argv[0]); 
+               if ((tflag == 1) && (volumesize <= 0)) fprintf(stderr,"Error: The volume size must be a non-zero value\n");
+               return (2);             
+       }
+               
+       if (cflag == 1) {
+               /* Comprimo */
+           return shuff_encode_file(argv[optind],argv[optind+1]);
+       }
        
+       if (dflag == 1) { 
+               /* Descomprimo */
+               return shuff_decode_file(argv[optind],argv[optind+1]);
+       }
+               
        return 0;
 }