X-Git-Url: https://git.llucax.com/z.facultad/75.06/jacu.git/blobdiff_plain/22942d33dcdd7cc185b9ad198fc1c35159f154ea..796cdcb3e421a88cf628fce1b20de546890ea106:/src/statichuff/statichuff.c diff --git a/src/statichuff/statichuff.c b/src/statichuff/statichuff.c index 2e2764a..6b3b4d5 100644 --- a/src/statichuff/statichuff.c +++ b/src/statichuff/statichuff.c @@ -3,6 +3,7 @@ #include #include +/** 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) { @@ -309,6 +345,7 @@ SHUFFNODE *shuff_decode_symbols(SHUFFNODE *entrynode, unsigned long int buffer, 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, int *decodedbytes) { SHUFFNODE *currnode = shuff->codetree; @@ -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); }