Added First Fit

FirstFit.java

@@ -0,0 +1,222 @@
+/*	David P. Turnbull
+	ITCS3146
+	group project
+	this class sets up a First Fit memory scheme
+*/
+
+//this section sets up the Car class
+class FirstFit
+{
+	
+	//this section sets up the private elements of the class
+	private int	jobId,
+					jobSize,
+					startLoc,
+					endLoc,
+					blkSize,
+					memSize=1024,
+					active,
+					noJobs=0,
+					s1=0,
+					chkCompress=0,
+					compMemTest=0,
+					tableEntries=1;
+	private int[] tempVal = new int[6];
+	private int[][] memTable = new int[memSize+2][6];
+	
+	
+	//this is a no argument constructor
+	public FirstFit()
+	{
+		memTable[0][0]=0;				//job number
+		memTable[0][1]=0;				//job size
+		memTable[0][2]=0;				//start location in memory
+		memTable[0][3]=memSize-1;	//end location in memory
+		memTable[0][4]=memSize;		//mem blk size size
+		memTable[0][5]=-1;			//status, 0=not active, 1=active, -1=special
+	}
+	
+	//this method sets the job up              need to modify the job class to return something
+	public void addJob(int ID, int size)
+	{
+		jobId = ID;
+		jobSize = size;
+		noJobs++;
+		s1=0;
+		
+		//checks to see if the job will fit in memory
+		if(jobSize>memSize)
+		{
+			System.out.println("\n\n*********************************************************"+
+										"         THIS JOB IS TO LARGE TO FIT INTO MEMORY"+
+										"*********************************************************");
+			System.exit(0);
+		}
+		
+		//this section looks for a place to put the new job
+		do
+		{
+			if(memTable[s1][5]==-1 && memTable[s1][4]>=jobSize && memTable[s1][3]==memSize-1)
+			{
+				//runs only for the first job
+				if(noJobs==1)
+				{
+					memTable[s1][0] = jobId;
+					memTable[s1][1] = jobSize;
+					memTable[s1][2] = 0;
+					memTable[s1][3] = jobSize-1;
+					memTable[s1][4] = memTable[0][3]-memTable[0][2]+1;
+					memTable[s1][5] = 1;
+					memTable[s1+1][0] = 0;
+					memTable[s1+1][1] = 0;
+					memTable[s1+1][2] = memTable[s1][3]+1;
+					memTable[s1+1][3] = memSize-1;
+					memTable[s1+1][4] = memSize-memTable[s1+1][2];
+					memTable[s1+1][5] = -1;
+					chkCompress=0;
+					tableEntries++;
+					s1=memSize*2;
+				}
+				//runs after the first job and if the only available slot is at the end of memory
+				else
+				{
+					memTable[s1][0] = jobId;
+					memTable[s1][1] = jobSize;
+					memTable[s1][2] = memTable[s1-1][3]+1;
+					memTable[s1][3] = jobSize+memTable[s1][2]-1;
+					memTable[s1][4] = memTable[s1][3]-memTable[s1][2]+1;
+					memTable[s1][5] = 1;
+					memTable[s1+1][0] = 0;
+					memTable[s1+1][1] = 0;
+					memTable[s1+1][2] = memTable[s1][3]+1;
+					memTable[s1+1][3] = memSize-1;
+					memTable[s1+1][4] = memSize-memTable[s1+1][2];
+					memTable[s1+1][5] = -1;
+					tableEntries++;
+					chkCompress=0;
+					s1=memSize*2;
+				}
+			}
+			//checks for first available free block that has been deallocated
+			else if(memTable[s1][4]>=jobSize && memTable[s1][5]==0)
+			{
+				memTable[s1][0] = jobId;
+				memTable[s1][1] = jobSize;
+				memTable[s1][5] = 1;
+				chkCompress=0;
+				s1=memSize*2;
+			}
+			else
+			{
+				s1++;
+			}
+		}while(s1<tableEntries);
+		
+		//this section runs if the job will not fit after memory compaction
+		if(chkCompress==1)
+		{
+			chkCompress=0;
+			System.out.println("put job back in queue");
+			//need to return that this job needs to be returned to the queue
+			System.exit(0);  
+		}
+		
+		//if job will not fit this section will compress memory and try placing the job again
+		if(s1==tableEntries && chkCompress==0)
+		{
+			noJobs=noJobs-1;
+			compMem();
+			chkCompress++;
+			addJob(ID, size);
+		}
+	}
+	
+	//this method removes a job it does not check to see if the job exisits
+	public void removeJob(int ID)
+	{
+		jobId = ID;
+		s1=0;
+		do
+		{
+			if(memTable[s1][0] == jobId)
+			{
+				memTable[s1][0] = 0;
+				memTable[s1][1] = 0;
+				memTable[s1][5] = 0;
+				s1=0;
+				jobId=-1;
+				noJobs--;
+			}
+			else
+			{
+				s1++;
+			}
+		
+		}while (jobId != -1 || s1<tableEntries);
+		
+	}
+	
+	//this method compacts the memory
+	public void compMem()
+	{
+		compMemTest=tableEntries;
+		for(int c=0; c<=compMemTest; c++)
+		{
+			//this section checks to see if two unused blks are next to each other and then
+			//comdines them
+			if(memTable[c][5]==0 && memTable[c+1][5]==0)
+			{
+				tempVal[0] = memTable[c+1][0];
+				tempVal[1] = memTable[c+1][1];
+				tempVal[2] = memTable[c+1][2];
+				tempVal[3] = memTable[c+1][3];
+				tempVal[4] = memTable[c+1][4];
+				tempVal[5] = memTable[c+1][5];
+				memTable[c+1][0]=-1;
+				memTable[c+1][1]=-1;
+				memTable[c+1][2]=-1;
+				memTable[c+1][3]=-1;
+				memTable[c+1][4]=-1;
+				memTable[c+1][5]=-1;
+				memTable[c][0]=0;
+				memTable[c][1]=0;
+				memTable[c][3]=tempVal[3];
+				memTable[c][4]=memTable[c][4]+tempVal[4];
+				memTable[c][5]=0;
+				//this loop shifts the remaining jobs up
+				for(int srt=c+1; srt<tableEntries; srt++)
+				{
+					memTable[srt][0]=memTable[srt+1][0];
+					memTable[srt][1]=memTable[srt+1][1];
+					memTable[srt][2]=memTable[srt+1][2];
+					memTable[srt][3]=memTable[srt+1][3];
+					memTable[srt][4]=memTable[srt+1][4];
+					memTable[srt][5]=memTable[srt+1][5];
+				}
+				memTable[tableEntries-1][0]=-1;
+				memTable[tableEntries-1][1]=-1;
+				memTable[tableEntries-1][2]=-1;
+				memTable[tableEntries-1][3]=-1;
+				memTable[tableEntries-1][4]=-1;
+				memTable[tableEntries-1][5]=-1;
+				c--;
+			}
+		}
+	}
+
+	//this method returns a String of all the elements stored in the object
+	public String toString()
+	{
+		String str;
+		str = ("\n\nJob ID\tJob Size\tStart Loc\tEnd Loc\tMem Blk Size\tStatus");
+		
+		for(int cnt=0; cnt<tableEntries; cnt++)
+		{
+		str = (str+"\n"+memTable[cnt][0]+"\t"+memTable[cnt][1]+"\t\t"+memTable[cnt][2]+"\t\t"+
+						memTable[cnt][3]+"\t\t"+memTable[cnt][4]+"\t"+memTable[cnt][5]);
+		}
+		
+		return str;
+	}
+	
+}