X-Git-Url: https://git.llucax.com/z.facultad/75.06/jacu.git/blobdiff_plain/d3fc39701c21dada8a143812c34e044b4b1ae704..2ee6f95a8db79ede018e0f15124dd486451c4170:/src/statichuff/statichuff.c?ds=inline

diff --git a/src/statichuff/statichuff.c b/src/statichuff/statichuff.c
index a2f6265..000f0ba 100644
--- a/src/statichuff/statichuff.c
+++ b/src/statichuff/statichuff.c
@@ -1,6 +1,7 @@
 
 #include "statichuff.h"
 #include <stdlib.h>
+#include <string.h>
 
 void putbit(char bit, char restart, char flush, VFILE *fp)
 {
@@ -69,15 +70,17 @@ int shuff_scanfreq_chunk(HUFF_STATE *chunkshuff, char* chunk, int chunksize)
 	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 */
@@ -272,7 +275,8 @@ int shuff_encode_file(HUFF_STATE *shuff)
 	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);
@@ -308,6 +312,36 @@ SHUFFNODE *shuff_decode_symbols(SHUFFNODE *entrynode, unsigned long int buffer,
 	else return shuff_decode_symbols(entrynode->rchild,buffer,bitsleft,symbol);
 }
 
+int shuff_decode_chunk(HUFF_STATE *shuff, char *chunk, int chunksize, 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 shuff_decode_file(HUFF_STATE *shuff)
 {	
 	SHUFFNODE *currnode;	
@@ -316,7 +350,7 @@ 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;
 	
@@ -338,6 +372,7 @@ int shuff_decode_file(HUFF_STATE *shuff)
 		}		
 	}
 			
+	/* Close destination */
 	fclose(fpdest);	
 	
 	return 1;
@@ -350,6 +385,8 @@ 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));
@@ -359,10 +396,11 @@ 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;
@@ -382,11 +420,11 @@ 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;
@@ -398,7 +436,7 @@ HUFF_STATE *shuff_init_encoder_bychunk(char *outputfile, long volsize)
 	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));
@@ -406,12 +444,12 @@ 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;	
@@ -419,14 +457,53 @@ HUFF_STATE *shuff_init_encoder_bychunk(char *outputfile, long volsize)
 	return cshuff;
 }
 
+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;	
+}
+
+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;
+}
+
 void shuff_deinit_encoder(HUFF_STATE *shuff)
 {
 	/* Libero mallocs y cierro archivos */
-	free(shuff->freqtable);	
-	if (shuff->coderfp != NULL) fclose(shuff->coderfp);
-	if (shuff->preloadfreq == 1) unlink(shuff->sourcefile);
-	free(shuff->sourcefile);
-	free(shuff->targetfile);			
+	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 */
 }
@@ -434,8 +511,8 @@ void shuff_deinit_encoder(HUFF_STATE *shuff)
 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);