public Stream GetFileStream(int tag, int level, int x, int y)
{
entry = new DirectoryEntry(tag, level, x, y, 0, 0);
UInt32 index = entry.ComputeHash() % (UInt32)(header.HashBuckets);
long hep = GetHashEntryPosition(index);
DirectoryEntry de;
while (hep != 0)
{
de = GetDirectoryEntry(hep);
if ((de.x == x) && (de.y == y) && ((de.tag == tag) || (tag == -1)) && (de.level == level))
{
return(StreamSlice.Create(dataStream, de.location, de.size));
}
else
{
hep = de.NextEntryInChain;
}
}
return(null);
}
public static async Task <Stream> GetImageStreamAsync(Stream f, int level, int x, int y, CancellationToken token)
{
var offset = GetFileIndexOffset(level, x, y);
f.Seek(offset, SeekOrigin.Begin);
var(start, length) = await GetNodeInfoAsync(f, offset, token).ConfigureAwait(false);
return(StreamSlice.Create(f, start, length));
}
public void SanityTest()
{
// Arrange
var bytes = _fixture.CreateMany<byte>().ToArray();
var offset = 1;
var length = bytes.Length - 2;
var subset = bytes.Skip(offset).Take(length);
// Act
using var ms = new MemoryStream(bytes);
using var sub = new StreamSlice(ms, offset, length);
// Assert
Assert.Equal(length, sub.Length);
Assert.Equal(offset, ms.Position);
Assert.Equal(sub.ToArray(), subset);
}
void StreamSliceSample()
{
Database db = GetDatabase();
Editor editor = GetEditor();
editor.WriteMessage("* StreamSlice *\n");
editor.WriteMessage("StreamSlice slices bodies with a plane.\n");
editor.WriteMessage("Pick some objects in the current drawing to be sliced and then pick three points to define the plane. The result profile will be highlighted.\n");
ObjectIdCollection ids = PickObjectSet("Please pick the bodies need to be sliced");
if (ids.Count == 0)
{
editor.WriteMessage("No object is picked\n");
return;
}
editor.WriteMessage("Now you need to pick 3 points from the screen to define the slicing plane.\n");
Plane plane = PromptPlane();
if (plane == null)
{
return;
}
StreamSlice stream = new StreamSlice(db, plane);
TransactionManager tm = db.TransactionManager;
using (Transaction trans = tm.StartTransaction())
{
stream.PushDisplayParameters(DictionaryDisplayConfiguration.GetStandardDisplayConfiguration(db), trans);
foreach (ObjectId id in ids)
{
Entity ent = trans.GetObject(id, OpenMode.ForRead) as Entity;
stream.Stream(ent);
}
stream.PopDisplayParameters();
trans.Commit();
}
HighlightProfile(stream.GetProfile(), plane);
}
public void ReallyLongStream(int offset, int length)
{
// Arrange
var bytes = new byte[1024 * 1024];
for (int i = 0; i < bytes.Length; i++)
{
bytes[i] = (byte)i;
}
var subset = bytes.Skip(offset).Take(length);
// Act
using var ms = new MemoryStream(bytes);
using var sub = new StreamSlice(ms, offset, length);
// Assert
Assert.Equal(length, sub.Length);
Assert.Equal(offset, ms.Position);
Assert.Equal(0, sub.Position);
Assert.Equal(sub.ToArray(), subset);
}
