#include "statichuff.h"
#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;
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;
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;
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;
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 */
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;
return inputlist;
}
+/** Genera el arbol de huffman en base a la tabla de frecuencias */
SHUFFNODE *shuff_buildtree(t_freq *ftable)
{
SHUFFNODE *lastsymbol;
return root;
}
+/** Imprime los codigos prefijos generados para los symbolos */
void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable)
{
int i,j;
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;
}
}
+/** Inicializa la tabla de codigos prefijos */
void shuff_zerocodes(SHUFFCODE *table)
{
int i;
}
}
+/** 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) {
}
}
+/** Realiza la compresion / encoding efectivo de un archivo */
int shuff_encode_symbols(HUFF_STATE *shuff, SHUFFCODE *ctable)
{
FILE *fpsource;
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;
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);
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)
{
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;
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;
}
}
+ /* Close destination */
fclose(fpdest);
return 1;
}
+/** Inicializa un descompresor de huffman */
HUFF_STATE *shuff_init_decoder(char *inputfile, char *outputfile)
{
/* Locals */
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->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 */
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));
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;
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);
}
projects / z.facultad / 75.06 / jacu.git / blobdiff