Miloris's Homework10

Homework10/2018202051XYB/compression.c

@@ -0,0 +1,125 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "zlib.h"
+#include "splay.h"
+#include "compression.h"
+
+// Read data to build original tree
+void read_data(FILE *fp){
+    int n = 0;
+    int i = 0;
+    double d = 0.0;
+    char c;
+    fscanf(fp, "%d", &n);	
+	for(i = 1; i <= n; i++){
+		fscanf(fp, "%lf %c", &d, &c);
+		insert_node(d, c);
+    }
+    return ;
+}
+
+
+void build_tree_from_raw_file(){
+    FILE* fin = fopen("data.in", "r");
+    read_data(fin);
+    fclose(fin);
+    return ;
+}
+
+void dfs_tree_save(char *buffer, struct tree_node *p){
+    if (p == NULL) {
+        sprintf(buffer + strlen(buffer), "0;");
+        return ;
+    }
+    sprintf(buffer + strlen(buffer), "1;%.3lf;%c;", p->val, p->c);
+    dfs_tree_save(buffer, p->ch[0]);
+    dfs_tree_save(buffer, p->ch[1]);
+    return ;
+}
+
+int save_tree_to_bin_file()
+{
+    // Create buffers
+    char *raw_buf = malloc(sizeof(char) * FILE_BUFFER),  // Temporary write
+         *cmp_buf = malloc(sizeof(char) * FILE_BUFFER);  // Compress
+    strcpy(raw_buf, "");
+    strcpy(cmp_buf, "");
+    // Dump tree to source buffer
+    dfs_tree_save(raw_buf, root);
+    // Compress buffer
+    unsigned long int dest_len = FILE_BUFFER,
+                      src_len = strlen(raw_buf);
+    int ret_res = compress2(cmp_buf, &dest_len, (const unsigned char*)raw_buf,
+                            src_len, Z_BEST_COMPRESSION);
+    if (ret_res != Z_OK) {
+        printf("Error while compressing data.\n");
+        free(raw_buf);
+        free(cmp_buf);
+        return 1;
+    }
+    // Write buffer to file
+    FILE* fout = fopen("compressed.sv", "wb");
+    printf("Finish: %d, %d\nCompression Ratio: %.2lf%%\n",
+            (int)src_len, (int)dest_len,
+            100.0 * (double)dest_len / (double)src_len);
+    fwrite(cmp_buf, sizeof(char), dest_len, fout);
+    fclose(fout);
+    // Finalize
+    free(raw_buf);
+    free(cmp_buf);
+    return 0;
+}
+
+
+
+struct tree_node* restore_node(char* buffer, int *pointer, struct tree_node *parent){
+    int is_valid_node = 0;
+    int scan_len = 0;
+    sscanf(buffer + *pointer, "%d;%n", &is_valid_node, &scan_len);
+    *pointer += scan_len;
+    if (!is_valid_node)
+        return NULL;
+    // Is not null node, read node data
+    struct tree_node *p = malloc(sizeof(struct tree_node));
+    sscanf(buffer + *pointer, "%lf;%c;%n", &p->val, &p->c, &scan_len);
+    *pointer += scan_len;
+    p->parent = parent;
+    p->ch[0] = restore_node(buffer, pointer, p);
+    p->ch[1] = restore_node(buffer, pointer, p);
+    p->size = 1 + (p->ch[0] ? p->ch[0]->size : 0) +
+              (p->ch[1] ? p->ch[1]->size : 0);
+    return p;
+}
+
+int load_tree_from_bin_file(){
+    // Create buffers
+    char *cmp_buf = malloc(sizeof(char) * FILE_BUFFER),  // Compressed data
+         *raw_buf = malloc(sizeof(char) * FILE_BUFFER);  // Actual data read
+    strcpy(cmp_buf, "");
+    strcpy(raw_buf, "");
+    // Read file into buffer
+    unsigned long int src_len = FILE_BUFFER,
+                      dest_len = FILE_BUFFER;
+    FILE* fin = fopen("compressed.sv", "rb");
+    fread(cmp_buf, sizeof(char), FILE_BUFFER, fin);
+    fclose(fin);
+    // Decompressing file
+	int ret_res = uncompress(raw_buf, &dest_len, (const unsigned char*)cmp_buf,src_len);
+    if (ret_res != Z_OK) {
+        printf("Error while compressing data.\n");
+        free(raw_buf);
+        free(cmp_buf);
+        return 1;
+    }
+    // Construct tree
+    int pointer = 0;
+    root = restore_node(raw_buf, &pointer, NULL);
+    // Finalize
+    free(raw_buf);
+    free(cmp_buf);
+    return 0;
+}
+
+

Homework10/2018202051XYB/compression.h

@@ -0,0 +1,22 @@
+#ifndef _COMPRESSION_H
+#define _COMPRESSION_H
+
+#define FILE_BUFFER 2097152
+/* 1;-10000.000;c; 15 chars for present node
+ * 0; 2 chars for empty node
+ * 15*100000 maximum, buffer open to 2097152
+ */
+
+void read_data(FILE *fp);
+
+void build_tree_from_raw_file();
+
+void dfs_tree_save(char *buffer, struct tree_node *p);
+
+int save_tree_to_bin_file();
+
+struct tree_node* restore_node(char *buffer, int *pointer, struct tree_node *parent);
+
+int load_tree_from_bin_file();
+
+#endif