public static void MergeRuns(DiskFunctionality df, string in1, string in2, string outTape) //merge 1 series from each input
{
int previous1Record = -1, record1 = df.ReadRecord(in1);
int previous2Record = -1, record2 = df.ReadRecord(in2);
while (true)
{
if (record1 != -1 && record2 != -1)
{
if (Compare(record1, record2))
{
if (Compare(previous1Record, record1))
{
df.SaveRecord(record1, outTape);
previous1Record = record1;
record1 = df.ReadRecord(in1);
}
else
{
df.ReturnRecord(in1);
while (true)
{
if (Compare(previous2Record, record2))
{
df.SaveRecord(record2, outTape);
previous2Record = record2;
record2 = df.ReadRecord(in2);
if (record2 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in2);
return;
}
}
}
}
else
{
if (Compare(previous2Record, record2))
{
df.SaveRecord(record2, outTape);
previous2Record = record2;
record2 = df.ReadRecord(in2);
}
else
{
df.ReturnRecord(in2);
while (true)
{
if (Compare(previous1Record, record1))
{
df.SaveRecord(record1, outTape);
previous1Record = record1;
record1 = df.ReadRecord(in1);
if (record1 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in1);
return;
}
}
}
}
}
else
{
if (record2 == -1)
{
while (true)
{
if (Compare(previous1Record, record1))
{
df.SaveRecord(record1, outTape);
previous1Record = record1;
record1 = df.ReadRecord(in1);
if (record1 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in1);
return;
}
}
}
else if (record1 == -1)
{
while (true)
{
if (Compare(previous2Record, record2))
{
df.SaveRecord(record2, outTape);
previous2Record = record2;
record2 = df.ReadRecord(in2);
if (record2 == -1)
{
return;
}
}
else
{
df.ReturnRecord(in2);
return;
}
}
}
else
{
return;
}
}
}
}
public static RunInfo DivideBetweenTapes(DiskFunctionality df, string main, string tape1, string tape2)
{
int record = -1, previousRecord;
int whichTape = 1, tape1Runs = 0, tape2Runs = 0, whichFibonacci = 0;
int fibbNumber = GetFibonacciNumber(whichFibonacci);
df.OpenReadStream(main);
df.OpenSaveStream(tape1);
df.OpenSaveStream(tape2);
while (true)
{
previousRecord = record;
record = df.ReadRecord(main);
if (record == -1)
{
break;
}
if (whichTape == 1)
{
if (Compare(previousRecord, record))
{
df.SaveRecord(record, tape1);
}
else
{
tape1Runs++;
if (tape1Runs == fibbNumber)
{
df.SaveRecord(record, tape2);
whichTape = 2;
whichFibonacci++;
fibbNumber = GetFibonacciNumber(whichFibonacci);
}
else
{
df.SaveRecord(record, tape1);
}
}
}
else
{
if (Compare(previousRecord, record))
{
df.SaveRecord(record, tape2);
}
else
{
tape2Runs++;
if (tape2Runs == fibbNumber)
{
df.SaveRecord(record, tape1);
whichTape = 1;
whichFibonacci++;
fibbNumber = GetFibonacciNumber(whichFibonacci);
}
else
{
df.SaveRecord(record, tape2);
}
}
}
}
if (whichTape == 1)// dummy runs
{
tape1Runs = GetFibonacciNumber(whichFibonacci);
}
else
{
tape2Runs = GetFibonacciNumber(whichFibonacci);
}
df.FlushRecordBuffer(tape1);
df.FlushRecordBuffer(tape2);
df.CloseStream(main);
df.CloseStream(tape1);
df.CloseStream(tape2);
Console.WriteLine("Divide finished. Sorting...");
return(new RunInfo(tape1Runs, tape2Runs));
}
