Initial commit - WPinternals 2.6

DiscUtils/Range.cs

@@ -0,0 +1,140 @@
+//
+// Copyright (c) 2008-2011, Kenneth Bell
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+//
+
+namespace DiscUtils
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Text;
+
+    /// <summary>
+    /// Represents a range of values.
+    /// </summary>
+    /// <typeparam name="TOffset">The type of the offset element.</typeparam>
+    /// <typeparam name="TCount">The type of the size element.</typeparam>
+    public class Range<TOffset, TCount> : IEquatable<Range<TOffset, TCount>>
+        where TOffset : IEquatable<TOffset>
+        where TCount : IEquatable<TCount>
+    {
+        private TOffset _offset;
+        private TCount _count;
+
+        /// <summary>
+        /// Initializes a new instance of the Range class.
+        /// </summary>
+        /// <param name="offset">The offset (i.e. start) of the range.</param>
+        /// <param name="count">The size of the range.</param>
+        public Range(TOffset offset, TCount count)
+        {
+            _offset = offset;
+            _count = count;
+        }
+
+        /// <summary>
+        /// Gets the offset (i.e. start) of the range.
+        /// </summary>
+        public TOffset Offset
+        {
+            get { return _offset; }
+        }
+
+        /// <summary>
+        /// Gets the size of the range.
+        /// </summary>
+        public TCount Count
+        {
+            get { return _count; }
+        }
+
+        /// <summary>
+        /// Merges sets of ranges into chunks.
+        /// </summary>
+        /// <param name="ranges">The ranges to merge.</param>
+        /// <param name="chunkSize">The size of each chunk.</param>
+        /// <returns>Ranges combined into larger chunks.</returns>
+        /// <typeparam name="T">The type of the offset and count in the ranges.</typeparam>
+        public static IEnumerable<Range<T, T>> Chunked<T>(IEnumerable<Range<T, T>> ranges, T chunkSize)
+            where T : struct, IEquatable<T>, IComparable<T>
+        {
+            T? chunkStart = Numbers<T>.Zero;
+            T chunkLength = Numbers<T>.Zero;
+
+            foreach (var range in ranges)
+            {
+                if (Numbers<T>.NotEqual(range.Count, Numbers<T>.Zero))
+                {
+                    T rangeStart = Numbers<T>.RoundDown(range.Offset, chunkSize);
+                    T rangeNext = Numbers<T>.RoundUp(Numbers<T>.Add(range.Offset, range.Count), chunkSize);
+
+                    if (chunkStart.HasValue && Numbers<T>.GreaterThan(rangeStart, Numbers<T>.Add(chunkStart.Value, chunkLength)))
+                    {
+                        // This extent is non-contiguous (in terms of blocks), so write out the last range and start new
+                        yield return new Range<T, T>(chunkStart.Value, chunkLength);
+                        chunkStart = rangeStart;
+                    }
+                    else if (!chunkStart.HasValue)
+                    {
+                        // First extent, so start first range
+                        chunkStart = rangeStart;
+                    }
+
+                    // Set the length of the current range, based on the end of this extent
+                    chunkLength = Numbers<T>.Subtract(rangeNext, chunkStart.Value);
+                }
+            }
+
+            // Final range (if any ranges at all) hasn't been returned yet, so do that now
+            if (chunkStart.HasValue)
+            {
+                yield return new Range<T, T>(chunkStart.Value, chunkLength);
+            }
+        }
+
+        /// <summary>
+        /// Returns a string representation of the extent as [start:+length].
+        /// </summary>
+        /// <returns>The string representation.</returns>
+        public override string ToString()
+        {
+            return "[" + _offset + ":+" + _count + "]";
+        }
+
+        #region IEquatable<Range<TOffset,TCount>> Members
+
+        /// <summary>
+        /// Compares this range to another.
+        /// </summary>
+        /// <param name="other">The range to compare.</param>
+        /// <returns><c>true</c> if the ranges are equivalent, else <c>false</c>.</returns>
+        public bool Equals(Range<TOffset, TCount> other)
+        {
+            if (other == null)
+            {
+                return false;
+            }
+
+            return _offset.Equals(other.Offset) && _count.Equals(other._count);
+        }
+
+        #endregion
+    }
+}