public void ReadThrowsIfWriteOnly()
{
var mem = new FixedMemory(10, canRead: false, canWrite: true);
var buf = new byte[5];
Assert.Throws <InvalidOperationException>(() => mem.Read(0, buf));
}
public void WriteThrowsIfWouldGoOutOfBounds()
{
var mem = new FixedMemory(10);
var buf = new byte[20];
Assert.Throws <IndexOutOfRangeException>(() => mem.Write(0, buf));
}
public void WriteSpanningTwoMemoriesWithAGapThrowsButDoesWriteEverythingBeforeTheGap()
{
var mem = new VirtualMemory();
var ram1 = new FixedMemory(10);
var ram2 = new FixedMemory(10);
mem.Attach(0, ram1);
mem.Attach(15, ram2);
var buf = CreateData(15);
Assert.Throws <InvalidOperationException>(() => mem.Write(5, buf.Span));
// Part of our contract is that we WILL write everything we could before the gap!
Assert.Equal(
new byte[] { 0, 0, 0, 0, 0, 1, 2, 3, 4, 5 },
ram1.Data.ToArray()
);
// But not after the gap
Assert.Equal(
new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
ram2.Data.ToArray()
);
}
public void WriteThrowsIfOffsetIsNegative()
{
var mem = new FixedMemory(10);
var buf = new byte[5];
var ex = Assert.Throws <ArgumentOutOfRangeException>(() => mem.Write(-1, buf));
Assert.Equal("offset", ex.ParamName);
}
public void InitializesWithAllZeros()
{
var mem = new FixedMemory(10);
var buf = new byte[10];
mem.Read(0, buf);
Assert.True(buf.All(b => b == 0));
}
public void WriteThrowsIfReadOnly()
{
var mem = new FixedMemory(10, canRead: true, canWrite: false);
var buf = new byte[5] {
1, 2, 3, 4, 5
};
Assert.Throws <InvalidOperationException>(() => mem.Write(0, buf));
}
public void CanBeInitializedWithData()
{
var data = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
var mem = new FixedMemory(data);
var buf = new byte[10];
mem.Read(0, buf);
Assert.Equal(data, buf);
}
public void WriteUpdatesData()
{
var mem = new FixedMemory(10);
var buf = new byte[5] {
1, 2, 3, 4, 5
};
mem.Write(2, buf.AsSpan());
Assert.Equal(new byte[] { 0, 0, 1, 2, 3, 4, 5, 0, 0, 0 }, mem.Data.ToArray());
}
public void WriteMirrorsAsManyTimesAsNecessaryToFillWrite()
{
var ram = new FixedMemory(5);
var mem = new MirroredMemory(20, ram);
var buf = CreateData(15);
mem.Write(3, buf.Span);
Assert.Equal(
new byte[] { 13, 14, 15, 11, 12 },
ram.Data.ToArray());
}
public void WriteContainedInOneMemory()
{
var mem = new VirtualMemory();
var ram1 = new FixedMemory(10);
mem.Attach(0, ram1);
var buf = CreateData(5);
mem.Write(1, buf.Span);
Assert.Equal(new byte[] { 0, 1, 2, 3, 4, 5, 0, 0, 0, 0 }, ram1.Data.ToArray());
}
public void WriteOutsideOfAnyMemoryThrows()
{
var mem = new VirtualMemory();
var ram1 = new FixedMemory(5);
var ram2 = new FixedMemory(5);
mem.Attach(0, ram1);
mem.Attach(20, ram2);
var buf = CreateData(5);
Assert.Throws <InvalidOperationException>(() => mem.Write(10, buf.Span));
}
public void AttachAndDetachUpdateLength()
{
var mem = new VirtualMemory();
var ram1 = new FixedMemory(10);
var ram2 = new FixedMemory(5);
mem.Attach(10, ram1);
mem.Attach(20, ram2);
Assert.Equal(25, mem.Length);
mem.Detach(ram2);
Assert.Equal(20, mem.Length);
}
public void AttachThrowsIfMemoriesWouldOverlap()
{
var mem = new VirtualMemory();
var ram1 = new FixedMemory(10);
var ram2 = new FixedMemory(5);
mem.Attach(10, ram1);
// Dangling off the end
Assert.Throws <InvalidOperationException>(() => mem.Attach(18, ram2));
// Fully contained within
Assert.Throws <InvalidOperationException>(() => mem.Attach(11, ram2));
// Dangling off the start
Assert.Throws <InvalidOperationException>(() => mem.Attach(9, ram2));
}
public void WriteSpanningTwoAdjacentMemories()
{
var mem = new VirtualMemory();
var ram1 = new FixedMemory(10);
var ram2 = new FixedMemory(10);
mem.Attach(0, ram1);
mem.Attach(10, ram2);
var buf = CreateData(10);
mem.Write(5, buf.Span);
Assert.Equal(
new byte[] { 0, 0, 0, 0, 0, 1, 2, 3, 4, 5 },
ram1.Data.ToArray());
Assert.Equal(
new byte[] { 6, 7, 8, 9, 10, 0, 0, 0, 0, 0 },
ram2.Data.ToArray());
}
