From 317af25699d28ecc87e160b2fc0be68bb192df53 Mon Sep 17 00:00:00 2001
From: vj586da <valer.jakubco@student.tuke.sk>
Date: Sun, 23 Jan 2022 23:01:39 +0100
Subject: [PATCH] add all

---
 sk2a/Makefile     |   8 +++
 sk2a/compressor.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++
 sk2a/compressor.h |  18 ++++++
 sk2a/main.c       |  24 ++++++++
 4 files changed, 186 insertions(+)
 create mode 100644 sk2a/Makefile
 create mode 100644 sk2a/compressor.c
 create mode 100644 sk2a/compressor.h
 create mode 100644 sk2a/main.c

diff --git a/sk2a/Makefile b/sk2a/Makefile
new file mode 100644
index 0000000..f451ff9
--- /dev/null
+++ b/sk2a/Makefile
@@ -0,0 +1,8 @@
+all: program
+
+program: compressor.c main.c
+	gcc -Wall -g compressor.c main.c -o program
+
+clean:
+	rm program
+
diff --git a/sk2a/compressor.c b/sk2a/compressor.c
new file mode 100644
index 0000000..d38206e
--- /dev/null
+++ b/sk2a/compressor.c
@@ -0,0 +1,136 @@
+#define _GNU_SOURCE
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "compressor.h"
+#define BUFSIZE 2000000 
+#define BSIZE 9
+
+int mycompress(char* buff,int size,char* outbuf){
+    //memcpy(outbuf,buff,size);
+	int k = 0;
+	int head = 0;
+	while(head < size && buff[head] > 0 ){
+		
+		int bufferSize = BSIZE;
+		if (head < bufferSize){
+			bufferSize = head;
+		}
+
+		char* searchBuffer = buff + head - bufferSize;
+
+		char* window = buff + head;
+
+		int lookAheadSize = BSIZE;
+		if((size - head) < lookAheadSize){
+			lookAheadSize = BSIZE - head;
+		}
+		//printf("Buffer: %s\n",buff);
+		//printf("window: %s\n", window);
+		//printf("head: %d\n", head);
+		int wsz = BSIZE;
+		int msz = wsz;
+        if (bufferSize < wsz){
+       		msz = bufferSize;
+        }
+		int offset = -1;
+
+		int size = -1;
+
+		for(int i = 1; i<msz; i++){
+			char* r = memmem(searchBuffer, bufferSize, window, i);
+			if(r > 0){
+				offset = bufferSize - ( r - searchBuffer );
+				size = i+1;
+			}else {
+				break;
+			}
+		}
+		
+
+		if(size > 0){
+			//printf("%d",offset);
+            //printf("%d",size-1);
+            //printf("%c\n",buff[head+size-1]);
+			sprintf(&outbuf[k],"%d%d%c",offset,size-1,buff[head+size-1]);
+			k+=3;
+			head+=size;
+			
+		}else {
+			//printf("00%c\n",buff[head]);
+			sprintf(&outbuf[k],"00%c",buff[head]);
+			k+=3;
+			head+=1;
+		}
+	
+	}
+
+	
+    return k;
+}
+
+
+void compress(FILE* infile,FILE* outfile){
+    char buffer[BUFSIZE];
+    memset(buffer,0,BUFSIZE);
+    while(1){
+        int insize = fread(buffer,sizeof(char),BUFSIZE,infile);
+        if (insize == 0){
+            if (feof(infile)){
+                // end of file
+                break;
+            }
+            assert(!ferror(infile));
+        }
+        char outbuf[BUFSIZE*2];
+        // Doplnte implementaciu kompresie. 
+        int outsize = mycompress(buffer,insize,outbuf);
+        if (outsize   > 0){
+            fwrite(outbuf,sizeof(char),outsize,outfile);
+        }
+    }
+}
+
+
+
+void decompress(FILE* infile,FILE* outfile){
+   	char code[3];
+    char buffer[BUFSIZE];
+	int size = 0;
+	int k = 0;
+	fseek(infile, 0, SEEK_END);
+	long fileSize = ftell(infile);
+	fseek(infile, 0, SEEK_SET);
+	printf("size: %ld\n", fileSize);
+	char letter;
+while(!feof(infile)){
+	size = 0;
+	memset(buffer,0,BUFSIZE);
+	for(int j = 0; j < 4096; j++){
+	fread(code, sizeof(char), 3, infile);
+	int offset = atoi(code);
+	int length = atoi(&code[1]);
+	letter = code[2];
+	offset=(offset-length)/10;
+	if(offset == 0){
+		buffer[size] = letter;
+		size++;
+	}else {
+		for(int i = 0; i < length; i++){
+			buffer[size] = buffer[size-offset];
+			size++;
+		} 
+		buffer[size] = letter;
+		size++;
+	}
+	printf("%d\n",k);
+	k+=3;
+}
+
+fwrite(buffer, sizeof(char), size-1, outfile);
+}
+
+
+}
+
diff --git a/sk2a/compressor.h b/sk2a/compressor.h
new file mode 100644
index 0000000..489a5f1
--- /dev/null
+++ b/sk2a/compressor.h
@@ -0,0 +1,18 @@
+#ifndef _COMPRESSORH
+#define _COMPRESSORH
+#include <stdio.h>
+
+/**
+ * Skomprimuje súbor in a zapíše do súboru out.
+ * @arg in smerník na otvorený vstupný súbor (na čítanie)
+ * @arg out smerník na otvorený výstupný súbor (na zápis)
+ */
+void compress(FILE* in, FILE* out);
+/**
+ * Dekomprimuje súbor in a zapíše do súboru out.
+ * @arg in smerník na otvorený vstupný súbor (na čítanie)
+ * @arg out smerník na otvorený výstupný súbor (na zápis)
+ */
+void decompress(FILE* in, FILE* out);
+
+#endif
diff --git a/sk2a/main.c b/sk2a/main.c
new file mode 100644
index 0000000..c4d3bc0
--- /dev/null
+++ b/sk2a/main.c
@@ -0,0 +1,24 @@
+#include "compressor.h"
+
+int main(int argc,char** argv){
+    if (argc != 4 || (argv[1][1] != 'c' && argv[1][1] != 'd')){
+        printf("Usage: \n");
+        printf("  Compress ./compress -c infile.txt outfile.compress\n");
+        printf("  decompress ./compress -d outfile.compress infile.txt\n");
+        return 0;
+    }
+    char* action = argv[1];
+    char* infile = argv[2];
+    char* outfile = argv[3];
+    FILE* inf = fopen(infile,"r");
+    FILE* outf = fopen(outfile,"w");
+    if (action[1] == 'c'){
+        compress(inf,outf);
+    }
+    else if (action[1] == 'd'){
+        decompress(inf,outf);
+    }
+    fclose(inf);
+    fclose(outf);
+}
+