/// <summary>
/// Initializes a new instance of the <see cref="SnapshotElementComparer" /> class.
/// </summary>
/// <param name="region">The parent region that contains this element.</param>
/// <param name="pointerIncrementMode">The method by which to increment element pointers.</param>
/// <param name="constraints">The constraints to use for the element comparisons.</param>
public unsafe SnapshotElementComparer(
SnapshotRegion region,
PointerIncrementMode pointerIncrementMode,
ConstraintNode constraints) : this(region, pointerIncrementMode)
{
this.ElementCompare = this.BuildCompareActions(constraints);
}
/// <summary>
/// Initializes a new instance of the <see cref="SnapshotElementIndexer" /> class.
/// </summary>
/// <param name="region">The parent region that contains this element.</param>
/// <param name="elementIndex">The index of the element to begin pointing to.</param>
public unsafe SnapshotElementIndexer(
SnapshotRegion region,
Int32 elementIndex = 0)
{
this.Region = region;
this.ElementIndex = elementIndex;
}
/// <summary>
/// Initializes a new instance of the <see cref="SnapshotElementVectorComparer" /> class.
/// </summary>
/// <param name="region">The parent region that contains this element.</param>
public SnapshotElementVectorComparer(SnapshotRegion region)
{
this.Region = region;
this.VectorSize = Vectors.VectorSize;
this.VectorReadBase = this.Region.ReadGroupOffset - this.Region.ReadGroupOffset % this.VectorSize;
this.VectorReadIndex = 0;
this.DataTypeSize = Conversions.SizeOf(this.Region.ReadGroup.ElementDataType);
this.ResultRegions = new List <SnapshotRegion>();
this.SetConstraintFunctions();
}
/// <summary>
/// Initializes a new instance of the <see cref="SnapshotElementComparer" /> class.
/// </summary>
/// <param name="region">The parent region that contains this element.</param>
/// <param name="pointerIncrementMode">The method by which to increment element pointers.</param>
/// <param name="constraints">The constraints to use for the element comparisons.</param>
public unsafe SnapshotElementComparer(SnapshotRegion region, PointerIncrementMode pointerIncrementMode, DataTypeBase dataType)
{
this.Region = region;
this.CurrentTypeCode = Type.GetTypeCode(dataType);
// The garbage collector can relocate variables at runtime. Since we use unsafe pointers, we need to keep these pinned
this.CurrentValuesHandle = GCHandle.Alloc(this.Region.ReadGroup.CurrentValues, GCHandleType.Pinned);
this.PreviousValuesHandle = GCHandle.Alloc(this.Region.ReadGroup.PreviousValues, GCHandleType.Pinned);
this.InitializePointers();
this.SetConstraintFunctions();
this.SetPointerFunction(pointerIncrementMode);
}
/// <summary>
/// Initializes a new instance of the <see cref="SnapshotElementVectorComparer" /> class.
/// </summary>
/// <param name="region">The parent region that contains this element.</param>
/// <param name="constraints">The set of constraints to use for the element comparisons.</param>
public SnapshotElementVectorComparer(SnapshotRegion region, ScanConstraints constraints)
{
this.Region = region;
this.VectorSize = Vectors.VectorSize;
this.VectorReadBase = this.Region.ReadGroupOffset - this.Region.ReadGroupOffset % this.VectorSize;
this.VectorReadIndex = 0;
this.DataType = constraints.ElementType;
this.DataTypeSize = constraints.ElementType.Size;
this.ResultRegions = new List <SnapshotRegion>();
this.SetConstraintFunctions();
this.VectorCompare = this.BuildCompareActions(constraints?.RootConstraint);
}
/// <summary>
/// Indexer to allow the retrieval of the element at the specified index. Notes: This does NOT index into a region.
/// </summary>
/// <param name="elementIndex">The index of the snapshot element.</param>
/// <returns>Returns the snapshot element at the specified index.</returns>
public SnapshotElementIndexer this[UInt64 elementIndex]
{
get
{
SnapshotRegion region = this.BinaryRegionSearch(elementIndex);
if (region == null)
{
return(null);
}
return(region[(elementIndex - region.BaseElementIndex).ToInt32()]);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="SnapshotElementComparer" /> class.
/// </summary>
/// <param name="region">The parent region that contains this element.</param>
/// <param name="pointerIncrementMode">The method by which to increment element pointers.</param>
/// <param name="constraints">The constraints to use for the element comparisons.</param>
public unsafe SnapshotElementComparer(SnapshotRegion region, PointerIncrementMode pointerIncrementMode, Constraint constraints, DataTypeBase dataType) : this(region, pointerIncrementMode, dataType)
{
this.ElementCompare = this.BuildCompareActions(constraints);
}
/// <summary>
/// Initializes a new instance of the <see cref="SnapshotElementVectorComparer" /> class.
/// </summary>
/// <param name="region">The parent region that contains this element.</param>
/// <param name="constraints">The set of constraints to use for the element comparisons.</param>
public SnapshotElementVectorComparer(SnapshotRegion region, ConstraintNode constraints) : this(region)
{
this.VectorCompare = this.BuildCompareActions(constraints);
}
/// <summary>
/// Finalizes any leftover snapshot regions and returns them.
/// </summary>
public IList <SnapshotRegion> GatherCollectedRegions()
{
// Create the final region if we are still encoding
if (this.Encoding)
{
this.ResultRegions.Add(new SnapshotRegion(this.Region.ReadGroup, this.VectorReadBase + this.VectorReadIndex - this.RunLength, this.RunLength));
this.RunLength = 0;
this.Encoding = false;
}
// Remove vector misaligned leading regions
SnapshotRegion firstRegion = this.ResultRegions.FirstOrDefault();
Int32 adjustedIndex = 0;
while (firstRegion != null)
{
// Exit if not misaligned
if (firstRegion.ReadGroupOffset >= this.Region.ReadGroupOffset)
{
break;
}
Int32 misalignment = this.Region.ReadGroupOffset - firstRegion.ReadGroupOffset;
if (firstRegion.RegionSize <= misalignment)
{
// The region is totally eclipsed -- remove it
this.ResultRegions.Remove(firstRegion);
}
else
{
// The region is partially eclipsed -- adjust the size
firstRegion.ReadGroupOffset += misalignment;
firstRegion.RegionSize -= misalignment;
adjustedIndex++;
}
firstRegion = this.ResultRegions.Skip(adjustedIndex).FirstOrDefault();
}
// Remove vector overreading trailing regions
SnapshotRegion lastRegion = this.ResultRegions.LastOrDefault();
adjustedIndex = 0;
while (lastRegion != null)
{
// Exit if not overreading
if (lastRegion.EndAddress <= this.Region.EndAddress)
{
break;
}
Int32 overread = (lastRegion.EndAddress - this.Region.EndAddress).ToInt32();
if (lastRegion.RegionSize <= overread)
{
// The region is totally eclipsed -- remove it
this.ResultRegions.Remove(lastRegion);
}
else
{
lastRegion.RegionSize -= overread;
adjustedIndex++;
}
lastRegion = this.ResultRegions.Reverse().Skip(adjustedIndex).FirstOrDefault();
}
return(this.ResultRegions);
}
