X-Git-Url: https://git.llucax.com/z.facultad/75.06/jacu.git/blobdiff_plain/22942d33dcdd7cc185b9ad198fc1c35159f154ea..d53cc94464bba53e0be1297ca0cc746901ec113b:/src/statichuff/statichuff.c?ds=inline

diff --git a/src/statichuff/statichuff.c b/src/statichuff/statichuff.c
index 2e2764a..f339ef0 100644
--- a/src/statichuff/statichuff.c
+++ b/src/statichuff/statichuff.c
@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+/** Coloca un bit en un buffer statico */
 void putbit(char bit, char restart, char flush, VFILE *fp)
 {
 	static unsigned long int bits_buffer = 0;
@@ -35,6 +36,7 @@ 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;
@@ -43,6 +45,7 @@ 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;
@@ -50,6 +53,23 @@ 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;
@@ -64,21 +84,24 @@ 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 */
@@ -87,6 +110,7 @@ int shuff_scanfreq_chunk(HUFF_STATE *chunkshuff, char* chunk, int chunksize)
 	return 1;
 }
 
+/** Escanea las frecuencias de un archivo y genera el modelo */
 int shuff_scanfreq(char *inputfile, t_freq *freqtable)
 {
 	/* Locals */	
@@ -116,6 +140,7 @@ 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;	
@@ -139,6 +164,7 @@ 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;
@@ -178,6 +204,7 @@ 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;
@@ -187,7 +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;			
-			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;
@@ -199,6 +226,7 @@ void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable)
 	}
 }
 
+/** Inicializa la tabla de codigos prefijos */
 void shuff_zerocodes(SHUFFCODE *table)
 {
 	int i;
@@ -210,6 +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) {
@@ -225,6 +254,7 @@ 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;
@@ -235,7 +265,10 @@ int shuff_encode_symbols(HUFF_STATE *shuff, SHUFFCODE *ctable)
 	SHUFFCODE symbolcode;
 		
 	/* Abrimos el source y el destino */
-	if (shuff->coderfp != NULL) fclose(shuff->coderfp); /* close bychunk temp file */
+	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;
 		
@@ -267,13 +300,15 @@ 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);
@@ -292,6 +327,7 @@ 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)
 {
@@ -309,7 +345,8 @@ 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)
+/** 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;	
@@ -339,6 +376,7 @@ int shuff_decode_chunk(HUFF_STATE *shuff, char *chunk, int chunksize, int *decod
 	else return 1;
 }
 
+/** Realiza la descompresión de un archivo comprimido */
 int shuff_decode_file(HUFF_STATE *shuff)
 {	
 	SHUFFNODE *currnode;	
@@ -375,6 +413,7 @@ int shuff_decode_file(HUFF_STATE *shuff)
 	return 1;
 }
 
+/** Inicializa un descompresor de huffman */
 HUFF_STATE *shuff_init_decoder(char *inputfile, char *outputfile)
 {
 	/* Locals */
@@ -396,13 +435,14 @@ HUFF_STATE *shuff_init_decoder(char *inputfile, char *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(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 */
@@ -418,7 +458,7 @@ HUFF_STATE *shuff_init_encoder_byfile(char *inputfile, char *outputfile, long vo
 	strcpy(fshuff->targetfile,outputfile);
 	fshuff->volsize = volsize;
 	fshuff->bychunk = 0;
-	fshuff->preloadfreq = 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;		
@@ -427,6 +467,7 @@ HUFF_STATE *shuff_init_encoder_byfile(char *inputfile, char *outputfile, long vo
 	return fshuff;
 }
 
+/** Inicializa compresor de huffman de a chunks */
 HUFF_STATE *shuff_init_encoder_bychunk(char *outputfile, long volsize)
 {
 	/* Locals */
@@ -442,7 +483,7 @@ HUFF_STATE *shuff_init_encoder_bychunk(char *outputfile, long volsize)
 	strcat(cshuff->sourcefile,"~");	
 	cshuff->volsize = volsize;
 	cshuff->bychunk = 1;
-	cshuff->preloadfreq = 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;	
@@ -454,6 +495,48 @@ 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 */
@@ -464,8 +547,10 @@ void shuff_deinit_encoder(HUFF_STATE *shuff)
 	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 */	
@@ -475,4 +560,5 @@ void shuff_deinit_decoder(HUFF_STATE *shuff)
 	if (shuff->decoderfp != NULL) vfclose(shuff->decoderfp);
 		
 	/* Destruyo recursivamente el arbol de codigos */
+	if (shuff->codetree) shuff_destroy_tree(shuff->codetree);
 }