private int ReadFromNullRemovalStream(byte[] input, byte[] buffer, StringBuilder sb, bool addMark)
{
using (var memoryStream = new MemoryStream(input))
using (var nullRemovalStream = new NullRemovalStream(memoryStream, addMark))
{
var readCount = nullRemovalStream.Read(buffer, 0, 4096);
var total = readCount;
while (readCount != 0)
{
sb.Append(Encoding.ASCII.GetString(buffer, 0, readCount));
readCount = nullRemovalStream.Read(buffer, 0, 4096);
total += readCount;
}
return(total);
}
}
public void TestInputWithRandomNullBytes(bool addMark, int maxNull)
{
var rand = new Random();
var size = 4096 * 4096;
var inputIndex = 0;
var input = new byte[size];
var expectedIndex = 0;
var expected = new byte[size];
var totalNull = 0;
var totalRead = 0;
var result = new StringBuilder();
var markTemplate = "[removed {0} null bytes]";
while (inputIndex < size)
{
int numberOfNull = maxNull < 2 ? maxNull : rand.Next(1, Math.Min(maxNull, size - inputIndex));
for (var i = inputIndex; i < inputIndex + numberOfNull; i++)
{
input[i] = 0;
if (numberOfNull < 60)
{
expected[expectedIndex++] = 0;
}
}
if (numberOfNull >= 60 && addMark)
{
foreach (var c in string.Format(markTemplate, numberOfNull))
{
expected[expectedIndex++] = (byte)c;
}
}
inputIndex += numberOfNull;
totalNull += numberOfNull;
if (inputIndex < size)
{
var numberOfChar = rand.Next(1, Math.Min(10, size - inputIndex));
for (var i = inputIndex; i < inputIndex + numberOfChar; i++)
{
input[i] = (byte)'a';
expected[expectedIndex++] = (byte)'a';
}
inputIndex += numberOfChar;
}
}
using (var nullRemovalStream = new NullRemovalStream(new MemoryStream(input), addMark))
{
var buffer = new byte[4096];
var readCount = nullRemovalStream.Read(buffer, 0, 4096);
while (readCount > 0)
{
totalRead += readCount;
result.Append(Encoding.ASCII.GetString(buffer, 0, readCount));
readCount = nullRemovalStream.Read(buffer, 0, 4096);
}
}
//File.WriteAllBytes($@"{Path.GetTempPath()}/1-input-{addMark}.txt",input);
//File.WriteAllBytes($@"{Path.GetTempPath()}/2-expected-{addMark}.txt",expected);
//File.WriteAllText($@"{Path.GetTempPath()}/3-result-{addMark}.txt",result.ToString());
// if the number of consecutive null bytes >= threshold, shrinking is guaranteed
Assert.True(maxNull < 60 ? totalRead == size : totalRead < size);
Assert.True(totalRead == expectedIndex);
var totalNumberOfA = input.Count(c => c == 'a');
Assert.AreEqual(size - totalNull, totalNumberOfA, "(number of a) and (size - number of null) should be equal!");
var expectedCount = expected.Count(c => c == 'a');
Assert.AreEqual(totalNumberOfA, expectedCount, "Expected buffer should contain same number of a!");
var processedCount = result.ToString().Count(c => c == 'a');
Assert.AreEqual(totalNumberOfA, processedCount, "Result sbuilder should contain same number of a!");
Assert.AreEqual(Encoding.ASCII.GetString(expected, 0, expectedIndex), result.ToString());
}
