Обновить sk1/compressor.c
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183e166d8b
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33192ea354
170
sk1/compressor.c
170
sk1/compressor.c
@ -16,6 +16,12 @@ typedef struct Node {
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struct Node *left, *right;
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} Node;
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typedef struct LZ77{
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int posun;
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int dlzka;
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char dalsi_znak;
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} LZ77;
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// Функция для создания нового узла
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Node* create_node(int symbol, unsigned int frequency) {
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Node* node = (Node*)malloc(sizeof(Node));
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@ -89,7 +95,7 @@ void free_huffman_tree(Node* root) {
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}
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// Функция сжатия данных с использованием алгоритма Хаффмана
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int compress_1(const char* input_file, const char* output_file) {
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int compress_2(const char* input_file, const char* output_file) {
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FILE* input = fopen(input_file, "rb");
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FILE* output = fopen(output_file, "wb");
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if (!input || !output) return -1;
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@ -160,7 +166,7 @@ int compress_1(const char* input_file, const char* output_file) {
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}
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// Функция декомпрессии данных с использованием алгоритма Хаффмана
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int decompress_1(const char* input_file, const char* output_file) {
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int decompress_2(const char* input_file, const char* output_file) {
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FILE* input = fopen(input_file, "rb");
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FILE* output = fopen(output_file, "wb");
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if (!input || !output) return -1;
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@ -198,10 +204,162 @@ int decompress_1(const char* input_file, const char* output_file) {
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return 0;
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}
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int compress_2(const char* input_file_name, const char* output_file_name){
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return 0;
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int compress_1(const char *input_file, const char *output_file) {
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FILE *source = fopen(input_file, "rb");
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if (source == NULL) {
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return -1;
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}
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int decompress_2(const char* input_file_name, const char* output_file_name){
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return 0;
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FILE *destination = fopen(output_file, "wb");
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if (destination == NULL) {
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fclose(source);
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return -1;
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}
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fseek(source, 0, SEEK_END);
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long file_size = ftell(source);
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if (file_size > 10 * 1024 * 1024) {
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fclose(source);
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fclose(destination);
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return -1;
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}
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fseek(source, 0, SEEK_SET); // Возврат в начало файла для чтения
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char *input_data = malloc(file_size);
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if (input_data == NULL) {
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fclose(source);
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fclose(destination);
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return -1;
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}
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fread(input_data, 1, file_size, source);
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int index = 0;
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while (index < file_size) {
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LZ77 element = {0, 0, input_data[index]}; // Инициализация элемента с текущим символом
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int best_length = 0, best_offset = 0;
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int start_idx;
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if ((index - WINDOW_CAPACITY) > 0) {
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start_idx = index - WINDOW_CAPACITY;
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} else {
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start_idx = 0;
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} // Поиск начала окна
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// Поиск наилучшего совпадения в окне
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for (int i = start_idx; i < index; i++) {
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int match_length = 0;
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while (match_length < MAX_MATCH_LENGTH && index + match_length < file_size &&
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input_data[i + match_length] == input_data[index + match_length]) {
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match_length++;
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}
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if (match_length > best_length) {
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best_length = match_length;
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best_offset = index - i;
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}
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if (match_length == MAX_MATCH_LENGTH) {
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break;
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}
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}
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// Если найдено совпадение записываем его в элемент иначе сохраняем символ
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if (best_length > 1) {
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element.posun = best_offset;
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element.dlzka = best_length;
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element.dalsi_znak = input_data[index + best_length];
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index += best_length + 1;
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} else {
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element.posun = 0;
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element.dlzka = 0;
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element.dalsi_znak = input_data[index];
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index++;
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}
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unsigned short combined = (element.posun << 4) | (element.dlzka & 0xF); // Объединение posun и dlzka в одно значение
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fwrite(&combined, sizeof(unsigned short), 1, destination);
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fwrite(&element.dalsi_znak, sizeof(char), 1, destination);
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}
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fwrite(&file_size, sizeof(file_size), 1, destination);
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free(input_data);
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fclose(source);
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fclose(destination);
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return ftell(destination);
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}
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int decompress_1(const char *input_file, const char *output_file) {
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FILE *source = fopen(input_file, "rb");
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if (source == NULL) {
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return -1;
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}
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FILE *destination = fopen(output_file, "wb");
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if (destination == NULL) {
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fclose(source);
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return -1;
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}
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char *buffer = malloc(WINDOW_CAPACITY);
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if (buffer == NULL) {
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fclose(source);
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fclose(destination);
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return -1;
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}
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memset(buffer, 0, WINDOW_CAPACITY);
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// Переход к концу файла для чтения размера исходного файла
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fseek(source, -sizeof(long), SEEK_END);
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long original_size;
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if (fread(&original_size, sizeof(long), 1, source) != 1) {
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free(buffer);
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fclose(source);
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fclose(destination);
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return -1;
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}
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// Возврат в начало файла для распаковки
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fseek(source, 0, SEEK_SET);
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int written_bytes = 0, buffer_position = 0;
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while (written_bytes < original_size) {
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unsigned short combined;
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char dalsi_znak;
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if (fread(&combined, sizeof(unsigned short), 1, source) != 1) {
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break;
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}
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if (fread(&dalsi_znak, sizeof(char), 1, source) != 1) {
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break;
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}
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int posun = combined >> 4;
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int dlzka = combined & 0xF;
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// Восстановление данных из совпадений в буфере
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if (dlzka > 0) {
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int start_idx = buffer_position - posun;
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for (int i = 0; i < dlzka; i++) {
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char current = buffer[(start_idx + i) % WINDOW_CAPACITY];
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fputc(current, destination);
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buffer[buffer_position % WINDOW_CAPACITY] = current;
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buffer_position++;
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written_bytes++;
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}
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}
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// Запись следующего символа в файл
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if (written_bytes < original_size) {
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fputc(dalsi_znak, destination);
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buffer[buffer_position % WINDOW_CAPACITY] = dalsi_znak;
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buffer_position++;
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written_bytes++;
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}
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}
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free(buffer);
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fclose(source);
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fclose(destination);
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return ftell(destination);
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}
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