1 files changed, 107 insertions, 0 deletions
diff --git a/src/fuse/cowMerger/src/merger.c b/src/fuse/cowMerger/src/merger.c
new file mode 100644
index 0000000..17926f7
--- /dev/null
+++ b/src/fuse/cowMerger/src/merger.c
@@ -0,0 +1,107 @@
+#include "merger.h"
+#define TestBit(A,k)    ( A[(k/32)] & (1 << (k%32)) )
+int fhImage;
+int fhCow;
+off_t *filePointers;
+uint64_t imageBlockCount;
+uint64_t size;
+
+bool merger(char *imageFilePath, char *cowFilePath){
+
+	if(!loadFiles(imageFilePath,  cowFilePath)){
+		return false;
+	}
+	if (merge()){
+		printf("File Merged");
+		return true;
+	}
+	return false;
+}
+
+
+
+
+bool loadFiles(char *imageFilePath, char *cowFilePath){
+
+	if((fhImage = open (imageFilePath, O_RDWR))==-1){
+				printf( "Could not open Image.\n" );
+				return false;
+	}
+	if((fhCow = open (cowFilePath, O_RDONLY))==-1){
+				printf( "Could not open Cow File.\n" );
+				close(fhImage);
+				return false;
+	}
+	unsigned int version ;
+
+	read(fhCow,&version,sizeof(unsigned int));
+	read(fhCow,&size,sizeof(uint64_t));
+	int l;
+	read(fhCow,&l,sizeof(int));
+
+	char *buffer = malloc(sizeof(char)*(l+1));
+	read(fhCow,buffer,l*sizeof(char));
+	buffer[l]='\0';
+
+	int pageSize;
+	read(fhCow,&pageSize,sizeof(int));
+	printf("Version: %u\n",version);
+	printf("länge: %i \n",l);
+	printf("Image Name: %s\n",buffer);
+	printf("Size: %ld\n", (long)size);
+	printf("pageSize: %i\n", (pageSize));
+	free(buffer);
+	//TODO Image Validation
+
+	imageBlockCount = ( size + (4096*256)-1 ) / (4096*256);
+
+	off_t mmapStart = lseek(fhCow, 0L, SEEK_CUR);
+	int maxPageSize = 8192;
+	mmapStart= ((mmapStart+maxPageSize-1)/maxPageSize)*maxPageSize;
+	filePointers = mmap(NULL,imageBlockCount*sizeof(off_t), PROT_READ, MAP_SHARED,fhCow, mmapStart);
+	if(filePointers == MAP_FAILED ){
+		printf("Error creating mmap in COW File.\n%s\nBye.\n ", strerror(errno));
+		close(fhCow);
+		close(fhImage);
+		return false;
+	}
+
+	return true;
+}
+
+
+bool merge(){
+	uint64_t mergedBlocks = 0;
+	for(uint64_t i = 0; i < imageBlockCount;i++){
+		printf("Merged %llu of %llu Blocks \n",i,imageBlockCount);
+		off_t pointer =(off_t)filePointers[i];
+		if(pointer !=0){
+			int blockState[8];
+			lseek(fhCow,filePointers[i],SEEK_SET);
+			read(fhCow,&blockState,sizeof(int)*8);
+			for(int j = 0; j < 256;j++){
+				if(TestBit(blockState,j)){
+					lseek(fhCow,filePointers[i]+(4096*(j+1)),SEEK_SET);
+					char buff[4096] = {0};
+					if(read(fhCow, &buff, 4096) < 0){
+						 printf("Error on reading Cow File. BigBlock: %llu\n",i);
+						 return false;
+					}
+					lseek(fhImage,(i*4096*256)+(4096*j),SEEK_SET);
+					if(write(fhImage, &buff, 4096) < 0){
+						 printf("Error on writing to File. BigBlock: %llu\n",i);
+						 return false;
+					}
+
+				}
+			}
+			mergedBlocks++;
+		}
+	}
+	printf("Merged %llu Blocks\n",mergedBlocks);
+	ftruncate(fhImage, size);
+	return true;
+}
+
+
+