Upgraded to .NET 5

Closes:
thorsten/ExaArray#1
thorsten/ExaArray#3
thorsten/ExaArray#4

.idea/.idea.ExaArray/.idea/codeStyles/codeStyleConfig.xml

@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Default" />
+  </state>
+</component>

ExaArray/ExaArray.csproj

@@ -1,18 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>netcoreapp3.1</TargetFramework>
+        <TargetFramework>net5.0</TargetFramework>
         <RootNamespace>Exa</RootNamespace>
         <PackageId>ExaArray</PackageId>
         <Authors>Thorsten Sommer</Authors>
         <Company>Thorsten Sommer</Company>
         <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
-        <PackageProjectUrl>https://code.tsommer.org/thorsten/ExaArray</PackageProjectUrl>
+        <PackageProjectUrl>https://github.com/SommerEngineering/ExaArray</PackageProjectUrl>
         <PackageLicenseExpression>BSD-3-Clause</PackageLicenseExpression>
         <RepositoryUrl>https://code.tsommer.org/thorsten/ExaArray</RepositoryUrl>
-        <PackageVersion>1.1.0</PackageVersion>
-        <AssemblyVersion>1.1.0</AssemblyVersion>
-        <FileVersion>1.1.0</FileVersion>
+        <PackageVersion>1.4.1-rc</PackageVersion>
+        <AssemblyVersion>1.4.1</AssemblyVersion>
+        <FileVersion>1.4.1</FileVersion>
     </PropertyGroup>
 
     <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">

ExaArray/ExaArray1D.Factories.cs

@@ -0,0 +1,265 @@
+using System;
+using System.Collections.Generic;
+
+namespace Exa
+{
+    public partial class ExaArray1D<T>
+    {
+        /// <summary>
+        /// Creates a new ExaArray1D from another. 
+        /// </summary>
+        /// <remarks>
+        /// When <c>T</c> is a value type, data gets copied as values. When <c>T</c> is a reference type, the pointers
+        /// to the original objects are copied. Thus, this factory method does not create a deep copy.
+        ///
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="other">The instance from which the new instance is to be created.</param>
+        /// <returns>The new instance</returns>
+        public static ExaArray1D<T> CreateFrom(ExaArray1D<T> other)
+        {
+            var next = new ExaArray1D<T>(other.OptimizationStrategy)
+            {
+                Length = other.Length,
+                chunks = new T[other.chunks.Length][]
+            };
+            
+            for (var n = 0; n < other.chunks.Length; n++)
+            {
+                next.chunks[n] =  new T[other.chunks[n].Length];
+                Array.Copy(other.chunks[n], next.chunks[n], other.chunks[n].Length);
+            }
+            
+            return next;
+        }
+
+        /// <summary>
+        /// Creates a new ExaArray1D from another, respecting the given range.
+        /// </summary>
+        /// <remarks>
+        /// When <c>T</c> is a value type, data gets copied as values. When <c>T</c> is a reference type, the pointers
+        /// to the original objects are copied. Thus, this factory method does not create a deep copy.
+        ///
+        /// Performance: O(n)
+        ///
+        /// The indices are inclusive.
+        /// </remarks>
+        /// <param name="other">The instance from which the new instance is to be created.</param>
+        /// <param name="indexFrom">The first source element which should be part of the new array.</param>
+        /// <param name="indexTo">The last source element which should be part of the new array.</param>
+        /// <returns>The new instance</returns>
+        /// <exception cref="IndexOutOfRangeException">Throws, when one or both of the indices are out of range.</exception>
+        public static ExaArray1D<T> CreateFrom(ExaArray1D<T> other, ulong indexFrom, ulong indexTo)
+        {
+            if (indexTo < indexFrom)
+                throw new IndexOutOfRangeException("Index to must be greater than index from.");
+            
+            if (indexTo >= other.Length || indexFrom >= other.Length)
+                throw new IndexOutOfRangeException("Index to must be within the range of the source.");
+            
+            //
+            // Determine the source start chunk and index.
+            //
+            int sourceChunkIndexTo = -1;
+            int sourceElementIndexTo = -1;
+            switch (other.OptimizationStrategy)
+            {
+                case Strategy.MAX_PERFORMANCE:
+                    sourceChunkIndexTo = (int) (indexTo / MAX_CAPACITY_ARRAY_PERFORMANCE);
+                    sourceElementIndexTo = (int) (indexTo - (ulong) sourceChunkIndexTo * MAX_CAPACITY_ARRAY_PERFORMANCE);
+                    break;
+                case Strategy.MAX_ELEMENTS:
+                    sourceChunkIndexTo = (int) (indexTo / MAX_CAPACITY_ARRAY);
+                    sourceElementIndexTo = (int) (indexTo - (ulong) sourceChunkIndexTo * MAX_CAPACITY_ARRAY);
+                    break;
+            }
+            
+            //
+            // Determine the source end chunk and index.
+            //
+            int sourceChunkIndexFrom = -1;
+            int sourceElementIndexFrom = -1;
+            switch (other.OptimizationStrategy)
+            {
+                case Strategy.MAX_PERFORMANCE:
+                    sourceChunkIndexFrom = (int) (indexFrom / MAX_CAPACITY_ARRAY_PERFORMANCE);
+                    sourceElementIndexFrom = (int) (indexFrom - (ulong) sourceChunkIndexFrom * MAX_CAPACITY_ARRAY_PERFORMANCE);
+                    break;
+                case Strategy.MAX_ELEMENTS:
+                    sourceChunkIndexFrom = (int) (indexFrom / MAX_CAPACITY_ARRAY);
+                    sourceElementIndexFrom = (int) (indexFrom - (ulong) sourceChunkIndexFrom * MAX_CAPACITY_ARRAY);
+                    break;
+            }
+            
+            // How many element we have to copy?
+            ulong newRange = indexTo - indexFrom + 1;
+            
+            //
+            // Determine, how many total chunks we need for the copy.
+            //
+            int destChunks = -1;
+            switch (other.OptimizationStrategy)
+            {
+                case Strategy.MAX_PERFORMANCE:
+                    destChunks = (int) ((newRange - 1) / MAX_CAPACITY_ARRAY_PERFORMANCE) + 1;
+                    break;
+                case Strategy.MAX_ELEMENTS:
+                    destChunks = (int) ((newRange - 1) / MAX_CAPACITY_ARRAY) + 1;
+                    break;
+            }
+
+            // Create the copy and allocate the needed number of outer chunk.
+            var next = new ExaArray1D<T>(other.OptimizationStrategy)
+            {
+                Length = newRange,
+                chunks = new T[destChunks][],
+            };
+            
+            //
+            // Variables for the copy process.
+            //
+            
+            int sourceChunkIndex = sourceChunkIndexFrom;
+            int destinationChunkIndex = 0;
+            int sourceElementIndex = sourceElementIndexFrom;
+            int destinationElementIndex = 0;
+            ulong leftOverTotal = newRange;
+
+            do
+            {
+                //
+                // Determine how many elements we copy next.
+                //
+
+                uint numberToCopy = 0;
+                
+                // Case: small number of elements from first chunk only
+                if (sourceChunkIndexFrom == sourceChunkIndexTo)
+                    numberToCopy = (uint) (sourceElementIndexTo - sourceElementIndexFrom + 1);
+                
+                // Case: this is first chunk of multiple chunks + start somewhere in the middle
+                else if (sourceElementIndex > 0)
+                    numberToCopy = (uint) (other.maxArrayCapacity - sourceElementIndex);
+                    
+                // Case: multiple chunks + we are in the middle of huge copy process + next chunk does __not__ exist
+                else if (next.chunks[destinationChunkIndex] == null && sourceElementIndex == 0 && leftOverTotal >= other.maxArrayCapacity)
+                    numberToCopy = other.maxArrayCapacity;
+                
+                // Case: multiple chunks + we are in the middle of huge copy process + next chunk does exist
+                else if (next.chunks[destinationChunkIndex] != null && sourceElementIndex == 0 && leftOverTotal >= other.maxArrayCapacity)
+                    numberToCopy = (uint) (other.maxArrayCapacity - next.chunks[destinationChunkIndex].Length);
+                
+                // Case: multiple chunks + this seems to be the last chunk
+                else if (sourceElementIndex == 0 && leftOverTotal < other.maxArrayCapacity)
+                    numberToCopy = (uint) leftOverTotal;
+                
+                //
+                // Can we allocate an entire chunk or do we have to fill up the existing
+                // chunk first?
+                //
+                if(next.chunks[destinationChunkIndex] == null)
+                    next.chunks[destinationChunkIndex] = new T[numberToCopy];
+                else
+                {
+                    var extended = new T[next.chunks[destinationChunkIndex].Length + numberToCopy];
+                    Array.Copy(next.chunks[destinationChunkIndex], extended, next.chunks[destinationChunkIndex].Length);
+                    next.chunks[destinationChunkIndex] = extended;
+                }
+                
+                // Copy the data:
+                Array.Copy(other.chunks[sourceChunkIndex], sourceElementIndex, next.chunks[destinationChunkIndex], destinationElementIndex, numberToCopy);
+
+                //
+                // Update the state machine.
+                //
+                var needNewDestinationChunk = next.chunks[destinationChunkIndex].Length == next.maxArrayCapacity;
+                var readNextSourceChunk = sourceElementIndex + numberToCopy == other.maxArrayCapacity;
+                var leftOverCurrentSourceChunk = (int) (readNextSourceChunk ? 0 : other.maxArrayCapacity - sourceElementIndex - numberToCopy);
+                
+                leftOverTotal -= numberToCopy;
+                sourceChunkIndex = readNextSourceChunk ? sourceChunkIndex + 1 : sourceChunkIndex;
+                destinationChunkIndex = needNewDestinationChunk ? destinationChunkIndex + 1 : destinationChunkIndex;
+                sourceElementIndex = leftOverCurrentSourceChunk;
+                destinationElementIndex = (int) (needNewDestinationChunk ? 0 : numberToCopy);
+
+            } while (leftOverTotal > 0);
+            return next;
+        }
+
+        /// <summary>
+        /// Creates a new ExaArray1D from an enumerable sequence of items. The number of items in the sequence is __unknown__.
+        /// </summary>
+        /// <remarks>
+        /// This factory method is slow because the number of items in the sequence is unknown. When you know the
+        /// number of items, you should use another factory method, where the number of items can be provided.
+        ///
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="sequence">The sequence to consume in order to create the array.</param>
+        /// <param name="strategy">The optional optimization strategy.</param>
+        /// <returns>The desired instance</returns>
+        public static ExaArray1D<T> CreateFrom(IEnumerable<T> sequence, Strategy strategy = Strategy.MAX_PERFORMANCE)
+        {
+            var inst = new ExaArray1D<T>(strategy);
+            ulong position = 0;
+            foreach (var element in sequence)
+            {
+                inst.Extend();
+                inst[position++] = element;
+            }
+
+            return inst;
+        }
+
+        /// <summary>
+        /// Creates a new ExaArray1D from an enumerable sequence of items. The number of items in the sequence is __known__.
+        /// </summary>
+        /// <remarks>
+        /// Creates an array with <c>length</c> items. When the sequence contains less elements, the remaining values are <c>default(T)</c>. 
+        /// When the sequence contains more elements, these additional elements getting ignored.
+        /// 
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="sequence">The sequence to consume in order to create the array.</param>
+        /// <param name="length">The number of elements in the sequence. When the sequence contains more elements, these additional elements are ignored.</param>
+        /// <param name="strategy">The optional optimization strategy.</param>
+        /// <returns>The desired instance</returns>
+        public static ExaArray1D<T> CreateFrom(IEnumerable<T> sequence, ulong length, Strategy strategy = Strategy.MAX_PERFORMANCE)
+        {
+            var inst = new ExaArray1D<T>(strategy);
+            inst.Extend(length);
+            
+            ulong position = 0;
+            foreach (var element in sequence)
+            {
+                if(position == length)
+                    break;
+
+                inst[position++] = element;
+            }
+
+            return inst;
+        }
+
+        /// <summary>
+        /// Creates a new ExaArray1D from a collection of items.
+        /// </summary>
+        /// <remarks>
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="collection">The collection to use</param>
+        /// <param name="strategy">The optional optimization strategy.</param>
+        /// <returns>The desired instance</returns>
+        public static ExaArray1D<T> CreateFrom(ICollection<T> collection, Strategy strategy = Strategy.MAX_PERFORMANCE)
+        {
+            var inst = new ExaArray1D<T>(strategy);
+            inst.Extend((ulong) collection.Count);
+            
+            ulong position = 0;
+            foreach (var element in collection)
+                inst[position++] = element;
+
+            return inst;
+        }
+    }
+}

ExaArray/ExaArray1D.cs

@@ -1,5 +1,8 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Runtime.Serialization.Formatters.Binary;
 
 namespace Exa
 {
@@ -8,7 +11,8 @@ namespace Exa
     /// to 4.6 quintillion (4,607,183,514,018,780,000) or 4.6 exa elements. 
     /// </summary>
     /// <typeparam name="T">The desired type to use, e.g. byte, int, etc.</typeparam>
-    public sealed class ExaArray1D<T>
+    [Serializable]
+    public sealed partial class ExaArray1D<T> : ISerializable
     {
         /// <summary>
         /// Unfortunately, this seems to be the maximal number of entries an
@@ -33,9 +37,6 @@ namespace Exa
         /// </summary>
         public const ulong MAX_NUMBER_ELEMENTS_PERFORMANCE = 1_152_921_504_606_850_000;
         
-        private readonly ulong maxCapacityArray;
-        private readonly ulong maxNumberElements;
-        
         /// <summary>
         /// Gets the configured optimization strategy.
         /// </summary>
@@ -44,24 +45,21 @@ namespace Exa
         // Chunk storage:
         private T[][] chunks = new T[1][];
         
+        // Max. array and chunk capacity:
+        private readonly uint maxArrayCapacity;
+        
+        // Max. number elements:
+        private readonly ulong maxElements;
+
         /// <summary>
         /// Creates an empty one-dimensional exa-scale array.
         /// </summary>
         public ExaArray1D(Strategy strategy = Strategy.MAX_PERFORMANCE)
         {
-            this.OptimizationStrategy = strategy;
             this.chunks[0] = new T[0];
-
-            if (this.OptimizationStrategy == Strategy.MAX_PERFORMANCE)
-            {
-                this.maxCapacityArray = MAX_CAPACITY_ARRAY_PERFORMANCE;
-                this.maxNumberElements = MAX_NUMBER_ELEMENTS_PERFORMANCE;
-            }
-            else
-            {
-                this.maxCapacityArray = MAX_CAPACITY_ARRAY;
-                this.maxNumberElements = MAX_NUMBER_ELEMENTS;
-            }
+            this.OptimizationStrategy = strategy;
+            this.maxElements = this.OptimizationStrategy == Strategy.MAX_PERFORMANCE ? MAX_NUMBER_ELEMENTS_PERFORMANCE : MAX_NUMBER_ELEMENTS;
+            this.maxArrayCapacity = this.OptimizationStrategy == Strategy.MAX_PERFORMANCE ? MAX_CAPACITY_ARRAY_PERFORMANCE : MAX_CAPACITY_ARRAY;
         }
 
         /// <summary>
@@ -81,15 +79,15 @@ namespace Exa
         /// <c>extendBy</c> argument exceeds the limit of 4,607,183,514,018,780,000 elements.</exception>
         public void Extend(ulong extendBy = 1)
         {
-            if(extendBy > this.maxNumberElements || this.Length + extendBy >= this.maxNumberElements)
-                throw new ArgumentOutOfRangeException($"It is not possible to extend more than {this.maxNumberElements} elements.");
+            if (extendBy > this.maxElements || this.Length + extendBy >= this.maxElements)
+                throw new ArgumentOutOfRangeException($"It is not possible to extend more than {this.maxElements} elements.");
 
             this.Length += extendBy;
-            var availableInCurrentChunk = this.maxCapacityArray - (ulong) (this.chunks[^1]?.Length ?? 0);
+            var availableInCurrentChunk = this.maxArrayCapacity - (ulong) (this.chunks[^1]?.Length ?? 0);
             if (extendBy >= (ulong)availableInCurrentChunk)
             {
                 // Extend the current chunk to its max:
-                var extendedInner = new T[this.maxCapacityArray];
+                var extendedInner = new T[this.maxArrayCapacity];
                 Array.Copy(this.chunks[^1], extendedInner, this.chunks[^1].Length);
                 this.chunks[^1] = extendedInner;
 
@@ -102,7 +100,7 @@ namespace Exa
 
                 do
                 {
-                    ulong allocating = leftOver >= this.maxCapacityArray ? this.maxCapacityArray : leftOver;
+                    ulong allocating = leftOver >= this.maxArrayCapacity ? this.maxArrayCapacity : leftOver;
                     leftOver -= allocating;
                     
                     // First, we allocate space for the new chunk:
@@ -145,21 +143,48 @@ namespace Exa
         {
             get
             {
-                if(index >= this.maxNumberElements)
+                if(index >= this.maxElements)
+                    throw new IndexOutOfRangeException();
+
+                int chunkIndex = -1;
+                int elementIndex = -1;
+                switch (this.OptimizationStrategy)
+                {
+                    case Strategy.MAX_PERFORMANCE:
+                        chunkIndex = (int) (index / MAX_CAPACITY_ARRAY_PERFORMANCE);
+                        elementIndex = (int) (index - (ulong) chunkIndex * MAX_CAPACITY_ARRAY_PERFORMANCE);
+                        break;
+                    case Strategy.MAX_ELEMENTS:
+                        chunkIndex = (int) (index / MAX_CAPACITY_ARRAY);
+                        elementIndex = (int) (index - (ulong) chunkIndex * MAX_CAPACITY_ARRAY);
+                        break;
+                }
+                
+                if (chunkIndex >= this.chunks.Length || elementIndex >= this.chunks[chunkIndex].Length)
                     throw new IndexOutOfRangeException();
                 
-                int chunkIndex = (int) (index / this.maxCapacityArray);
-                int elementIndex = (int) (index - (ulong) chunkIndex * this.maxCapacityArray);
                 return this.chunks[chunkIndex][elementIndex];
             }
 
             set
             {
-                if(index >= this.maxNumberElements)
+                if(index >= this.maxElements)
                     throw new IndexOutOfRangeException();
                 
-                int chunkIndex = (int) (index / this.maxCapacityArray);
-                int elementIndex = (int) (index - (ulong) chunkIndex * this.maxCapacityArray);
+                int chunkIndex = -1;
+                int elementIndex = -1;
+                switch (this.OptimizationStrategy)
+                {
+                    case Strategy.MAX_PERFORMANCE:
+                        chunkIndex = (int) (index / MAX_CAPACITY_ARRAY_PERFORMANCE);
+                        elementIndex = (int) (index - (ulong) chunkIndex * MAX_CAPACITY_ARRAY_PERFORMANCE);
+                        break;
+                    case Strategy.MAX_ELEMENTS:
+                        chunkIndex = (int) (index / MAX_CAPACITY_ARRAY);
+                        elementIndex = (int) (index - (ulong) chunkIndex * MAX_CAPACITY_ARRAY);
+                        break;
+                }
+                
                 if (chunkIndex >= this.chunks.Length || elementIndex >= this.chunks[chunkIndex].Length)
                     throw new IndexOutOfRangeException();
 
@@ -167,6 +192,23 @@ namespace Exa
             }
         }
 
+        /// <summary>
+        /// Creates a new ExaArray1D from this instance, respecting the given range.
+        /// </summary>
+        /// <remarks>
+        /// When <c>T</c> is a value type, data gets copied as values. When <c>T</c> is a reference type, the pointers
+        /// to the original objects are copied. Thus, this factory method does not create a deep copy.
+        ///
+        /// Performance: O(n)
+        ///
+        /// The indices are inclusive.
+        /// </remarks>
+        /// <param name="indexFrom">The first source element which should be part of the new array.</param>
+        /// <param name="indexTo">The last source element which should be part of the new array.</param>
+        /// <returns>The new instance</returns>
+        /// <exception cref="IndexOutOfRangeException">Throws, when one or both of the indices are out of range.</exception>
+        public ExaArray1D<T> this[ulong indexFrom, ulong indexTo] => ExaArray1D<T>.CreateFrom(this, indexFrom, indexTo);
+
         /// <summary>
         /// Yields an enumerator across all elements.
         /// </summary>
@@ -180,5 +222,72 @@ namespace Exa
             for (ulong n = 0; n < this.Length; n++)
                 yield return this[n];
         }
+
+        #region Store and load
+
+        /// <summary>
+        /// Stores the exa array into a stream. <b>Please read the remarks regarding security issues.</b>
+        /// </summary>
+        /// <remarks>
+        /// The data stored in this way should never be part of a public API. Serializing and
+        /// deserializing is not secure: an attacker can manipulate the data in a targeted
+        /// manner to compromise the API server, etc.
+        ///
+        /// This method does not dispose the stream.
+        /// </remarks>
+        public void Store(Stream outputStream)
+        {
+            var formatter = new BinaryFormatter();
+            formatter.Serialize(outputStream, this);
+        }
+
+        /// <summary>
+        /// Restores an exa array from the given stream. <b>Please read the remarks regarding security issues.</b>
+        /// </summary>
+        /// <remarks>
+        /// The data loaded in this way should never be part of a public API. Serializing and
+        /// deserializing is not secure: an attacker can manipulate the data in a targeted
+        /// manner to compromise the API server, etc.
+        /// 
+        /// This method does not dispose the stream.
+        /// </remarks>
+        public static ExaArray1D<T> Restore(Stream inputStream)
+        {
+            var formatter = new BinaryFormatter();
+            return formatter.Deserialize(inputStream) as ExaArray1D<T>;
+        }
+
+        #endregion
+
+        #region Serialization
+
+        /// <summary>
+        /// This method serves for the serialization process. Do not call it manually. 
+        /// </summary>
+        public void GetObjectData(SerializationInfo info, StreamingContext context)
+        {
+            info.AddValue("version", "v1");
+            info.AddValue("strategy", this.OptimizationStrategy, typeof(Strategy));
+            info.AddValue("length", this.Length);
+            info.AddValue("chunks", this.chunks, typeof(T[][]));
+        }
+        
+        private ExaArray1D(SerializationInfo info, StreamingContext context)
+        {
+            switch (info.GetString("version"))
+            {
+                case "v1":
+                    this.Length = info.GetUInt64("length");
+                    this.chunks = info.GetValue("chunks", typeof(T[][])) as T[][];
+                    this.OptimizationStrategy = (Strategy) info.GetValue("strategy", typeof(Strategy));
+                    break;
+            }
+
+            this.chunks[0] ??= new T[0];
+            this.maxElements = this.OptimizationStrategy == Strategy.MAX_PERFORMANCE ? MAX_NUMBER_ELEMENTS_PERFORMANCE : MAX_NUMBER_ELEMENTS;
+            this.maxArrayCapacity = this.OptimizationStrategy == Strategy.MAX_PERFORMANCE ? MAX_CAPACITY_ARRAY_PERFORMANCE : MAX_CAPACITY_ARRAY;
+        }
+
+        #endregion
     }
 }

ExaArray/ExaArray2D.cs

@@ -0,0 +1,151 @@
+using System;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Runtime.Serialization.Formatters.Binary;
+
+namespace Exa
+{
+    /// <summary>
+    /// The two-dimensional exa-scale array. Can grow up to 18,446,744,073,709,551,615 elements in total.
+    /// </summary>
+    [Serializable]
+    public sealed class ExaArray2D<T> : ISerializable
+    {
+        /// <summary>
+        /// The total number of possible elements.
+        /// </summary>
+        public const ulong MAX_NUMBER_ELEMENTS = ulong.MaxValue;
+
+        private ulong sumLengthOrdinates = 0;
+        
+        // Chunk storage:
+        private readonly ExaArray1D<ExaArray1D<T>> chunks = new ExaArray1D<ExaArray1D<T>>(Strategy.MAX_PERFORMANCE);
+
+        /// <summary>
+        /// Constructs a two-dimensional exa-scale array.
+        /// </summary>
+        public ExaArray2D()
+        {
+        }
+        
+        /// <summary>
+        /// Returns the current total number of elements across all dimensions. 
+        /// </summary>
+        /// <remarks>
+        /// Performance: O(1)
+        /// </remarks>
+        public ulong Length => this.sumLengthOrdinates;
+
+        /// <summary>
+        /// Gets or sets an element of the array.
+        /// </summary>
+        /// <remarks>
+        /// Getting a value: When asking for elements which are not yet allocated, returns <c>default(T)</c>. Performance: O(1).
+        /// 
+        /// Setting a value: The underlying data structure gets extended on demand as necessary. The array can and will grow
+        /// on demand per index. For example, the abscissa index 5 might have allocated memory for 15 elements while abscissa
+        /// index 16 have allocated memory for 1,000 elements.
+        ///
+        /// Performance, when the memory is already allocated: O(1)
+        /// Performance to extend on demand: O(n)
+        ///
+        /// On the abscissa, you extend up to 1,152,921,504,606,850,000 entries. Across all dimensions, you can have 18,446,744,073,709,551,615
+        /// elements on total.
+        /// </remarks>
+        /// <exception cref="ArgumentOutOfRangeException">Throws, when you tried to extend more than 1,152,921,504,606,850,000 elements on the abscissa
+        /// or you tried to extend to more than 18,446,744,073,709,551,615 elements in total.</exception>
+        public T this[ulong indexAbscissa, ulong indexOrdinate]
+        {
+            get
+            {
+                if (this.chunks.Length == 0 || indexAbscissa >= this.chunks.Length || indexOrdinate >= this.chunks[indexAbscissa]?.Length)
+                    return default(T);
+
+                return this.chunks[indexAbscissa][indexOrdinate];
+            }
+
+            set
+            {
+                if(this.chunks.Length == 0 || indexAbscissa >= this.chunks.Length)
+                    this.chunks.Extend(indexAbscissa - this.chunks.Length + 1);
+                
+                this.chunks[indexAbscissa] ??= new ExaArray1D<T>(Strategy.MAX_PERFORMANCE);
+                if(this.chunks[indexAbscissa].Length == 0 || indexOrdinate >= this.chunks[indexAbscissa].Length - 1)
+                {
+                    var extendBy = (indexOrdinate - this.chunks[indexAbscissa].Length) + 1;
+                    if(extendBy > MAX_NUMBER_ELEMENTS - this.sumLengthOrdinates)
+                        throw new ArgumentOutOfRangeException($"It is not possible to extend more than {MAX_NUMBER_ELEMENTS} total elements across all dimensions.");
+                    
+                    this.chunks[indexAbscissa].Extend(extendBy);
+                    this.sumLengthOrdinates += extendBy;
+                }
+
+                this.chunks[indexAbscissa][indexOrdinate] = value;
+            }
+        }
+        
+        #region Store and load
+
+        /// <summary>
+        /// Stores the exa array into a stream. <b>Please read the remarks regarding security issues.</b>
+        /// </summary>
+        /// <remarks>
+        /// The data stored in this way should never be part of a public API. Serializing and
+        /// deserializing is not secure: an attacker can manipulate the data in a targeted
+        /// manner to compromise the API server, etc.
+        ///
+        /// This method does not dispose the stream.
+        /// </remarks>
+        public void Store(Stream outputStream)
+        {
+            var formatter = new BinaryFormatter();
+            formatter.Serialize(outputStream, this);
+        }
+
+        /// <summary>
+        /// Restores an exa array from the given stream. <b>Please read the remarks regarding security issues.</b>
+        /// </summary>
+        /// <remarks>
+        /// The data loaded in this way should never be part of a public API. Serializing and
+        /// deserializing is not secure: an attacker can manipulate the data in a targeted
+        /// manner to compromise the API server, etc.
+        /// 
+        /// This method does not dispose the stream.
+        /// </remarks>
+        public static ExaArray2D<T> Restore(Stream inputStream)
+        {
+            var formatter = new BinaryFormatter();
+            return formatter.Deserialize(inputStream) as ExaArray2D<T>;
+        }
+
+        #endregion
+        
+        #region Serialization
+
+        /// <summary>
+        /// This method serves for the serialization process. Do not call it manually. 
+        /// </summary>
+        public void GetObjectData(SerializationInfo info, StreamingContext context)
+        {
+            info.AddValue("version", "v1");
+            info.AddValue("length", this.Length);
+            info.AddValue("chunks", this.chunks, typeof(ExaArray1D<ExaArray1D<T>>));
+        }
+        
+        private ExaArray2D(SerializationInfo info, StreamingContext context)
+        {
+            switch (info.GetString("version"))
+            {
+                case "v1":
+                    this.sumLengthOrdinates = info.GetUInt64("length");
+                    this.chunks = info.GetValue("chunks", typeof(ExaArray1D<ExaArray1D<T>>)) as ExaArray1D<ExaArray1D<T>>;
+                    break;
+
+                default:
+                    break;
+            }
+        }
+
+        #endregion
+    }
+}

ExaArray/Extensions.ExaArray1D.cs

@@ -0,0 +1,41 @@
+using System;
+
+namespace Exa
+{
+    /// <summary>
+    /// Extension methods for <c>ExaArray1D</c>.
+    /// </summary>
+    public static class ExtensionsExaArray1D
+    {
+        /// <summary>
+        /// Creates a new ExaArray1D from this instance. 
+        /// </summary>
+        /// <remarks>
+        /// When <c>T</c> is a value type, data gets copied as values. When <c>T</c> is a reference type, the pointers
+        /// to the original objects are copied. Thus, this factory method does not create a deep copy.
+        ///
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="other">The instance from which the new instance is to be created.</param>
+        /// <returns>The new instance</returns>
+        public static ExaArray1D<T> Clone<T>(this ExaArray1D<T> other) => ExaArray1D<T>.CreateFrom(other);
+
+        /// <summary>
+        /// Creates a new ExaArray1D from this instance, respecting the given range.
+        /// </summary>
+        /// <remarks>
+        /// When <c>T</c> is a value type, data gets copied as values. When <c>T</c> is a reference type, the pointers
+        /// to the original objects are copied. Thus, this factory method does not create a deep copy.
+        ///
+        /// Performance: O(n)
+        ///
+        /// The indices are inclusive.
+        /// </remarks>
+        /// <param name="other">The instance from which the new instance is to be created.</param>
+        /// <param name="indexFrom">The first source element which should be part of the new array.</param>
+        /// <param name="indexTo">The last source element which should be part of the new array.</param>
+        /// <returns>The new instance</returns>
+        /// <exception cref="IndexOutOfRangeException">Throws, when one or both of the indices are out of range.</exception>
+        public static ExaArray1D<T> Clone<T>(this ExaArray1D<T> other, ulong indexFrom, ulong indexTo) => ExaArray1D<T>.CreateFrom(other, indexFrom, indexTo);
+    }
+}

ExaArray/Extensions.Framework.cs

@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+
+namespace Exa
+{
+    /// <summary>
+    /// Contains extension methods.
+    /// </summary>
+    public static class ExtensionsFramework
+    {
+        /// <summary>
+        /// Creates a new ExaArray1D from this collection of items.
+        /// </summary>
+        /// <remarks>
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="collection">The collection to use</param>
+        /// <param name="strategy">The optional optimization strategy.</param>
+        /// <returns>The desired instance</returns>
+        public static ExaArray1D<T> AsExaArray<T>(this ICollection<T> collection, Strategy strategy = Strategy.MAX_PERFORMANCE) => ExaArray1D<T>.CreateFrom(collection, strategy);
+
+        /// <summary>
+        /// Creates a new ExaArray1D from this enumerable sequence of items. The number of items in the sequence is __known__.
+        /// </summary>
+        /// <remarks>
+        /// Creates an array with <c>length</c> items. When this sequence contains less elements, the remaining values are <c>default(T)</c>. 
+        /// When the sequence contains more elements, these additional elements getting ignored.
+        /// 
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="sequence">The sequence to consume in order to create the array.</param>
+        /// <param name="length">The number of elements in the sequence. When the sequence contains more elements, these additional elements are ignored.</param>
+        /// <param name="strategy">The optional optimization strategy.</param>
+        /// <returns>The desired instance</returns>
+        public static ExaArray1D<T> AsExaArray<T>(this IEnumerable<T> sequence, ulong length, Strategy strategy = Strategy.MAX_PERFORMANCE) => ExaArray1D<T>.CreateFrom(sequence, length, strategy);
+
+        /// <summary>
+        /// Creates a new ExaArray1D from this enumerable sequence of items. The number of items in the sequence is __unknown__.
+        /// </summary>
+        /// <remarks>
+        /// This method is slow because the number of items in this sequence is unknown. When you know the
+        /// number of items, you should use another factory method, where the number of items can be provided.
+        ///
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="sequence">The sequence to consume in order to create the array.</param>
+        /// <param name="strategy">The optional optimization strategy.</param>
+        /// <returns>The desired instance</returns>
+        public static ExaArray1D<T> AsExaArray<T>(this IEnumerable<T> sequence, Strategy strategy = Strategy.MAX_PERFORMANCE) => ExaArray1D<T>.CreateFrom(sequence, strategy);
+    }
+}

ExaArrayTests/ExaArray1DTests.cs

@@ -1,6 +1,8 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Exa;
@@ -8,12 +10,18 @@ using NUnit.Framework;
 
 namespace ExaArrayTests
 {
+    [ExcludeFromCodeCoverage]
     public class ExaArray1DTests
     {
-        [ExcludeFromCodeCoverage]
-        public class InfinityArrayTests
+        [Serializable]
+        private class TestClass
         {
+            public int Age { get; set; }
+        }
+
         [Test]
+        [Category("cover")]
+        [Category("normal")]
         public void CreatingNormalSize01()
         {
             var exaA = new ExaArray1D<byte>();
@@ -36,6 +44,8 @@ namespace ExaArrayTests
         }
 
         [Test]
+        [Category("cover")]
+        [Category("normal")]
         public void CreatingNormalSize02()
         {
             var exaA = new ExaArray1D<int>();
@@ -54,6 +64,129 @@ namespace ExaArrayTests
         }
 
         [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void ExtendingTooFar01()
+        {
+            var exaA = new ExaArray1D<byte>();
+            Assert.Throws<ArgumentOutOfRangeException>(() =>
+            {
+                // Cannot handle more than 1.1 quintillion elements: 
+                exaA.Extend(ulong.MaxValue);
+            });
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void ExtendingToEndFirstChunk01()
+        {
+            const uint MAX = 1_073_741_824;
+            var exaA = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exaA.Extend(MAX - 2);
+
+            Assert.That(exaA.Length, Is.EqualTo(MAX - 2));
+
+            exaA.Extend(2);
+            Assert.That(exaA.Length, Is.EqualTo(MAX));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void GetInvalidIndex01()
+        {
+            var exaPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exaPerf.Extend(2);
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var t = exaPerf[ulong.MaxValue]; // Because index >= max
+            });
+
+            Assert.DoesNotThrow(() =>
+            {
+                var t1 = exaPerf[0];
+                var t2 = exaPerf[1];
+            });
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var t = exaPerf[2]; // Because we don't allocate
+            });
+
+            exaPerf = null;
+
+
+            var exaElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+            exaElem.Extend(2);
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var t = exaElem[ulong.MaxValue]; // Because index >= max
+            });
+
+            Assert.DoesNotThrow(() =>
+            {
+                var t1 = exaElem[0];
+                var t2 = exaElem[1];
+            });
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var t = exaElem[2]; // Because we don't allocate
+            });
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void SetInvalidIndex01()
+        {
+            var exaPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exaPerf.Extend(2);
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                exaPerf[ulong.MaxValue] = 0x00; // Because index >= max
+            });
+
+            Assert.DoesNotThrow(() =>
+            {
+                exaPerf[0] = 0x01;
+                exaPerf[1] = 0x02;
+            });
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var t = exaPerf[2] = 0x03; // Because we don't allocate
+            });
+
+            exaPerf = null;
+
+
+            var exaElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+            exaElem.Extend(2);
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                exaElem[ulong.MaxValue] = 0x00; // Because index >= max
+            });
+
+            Assert.DoesNotThrow(() =>
+            {
+                exaElem[0] = 0x01;
+                exaElem[1] = 0x02;
+            });
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                exaElem[2] = 0x03; // Because we don't allocate
+            });
+        }
+
+        [Test]
+        [Category("intensive")]
         public void CountingHugeSize01()
         {
             var exaA = new ExaArray1D<byte>();
@@ -68,6 +201,457 @@ namespace ExaArrayTests
         }
 
         [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFrom001()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(2);
+            exPerf[0] = 0x01;
+            exPerf[1] = 0x02;
+
+            var next = ExaArray1D<byte>.CreateFrom(exPerf);
+            Assert.That(next.Length, Is.EqualTo(exPerf.Length));
+            Assert.That(next.OptimizationStrategy, Is.EqualTo(exPerf.OptimizationStrategy));
+            Assert.That(next.Items(), Is.EquivalentTo(exPerf.Items()));
+
+            exPerf = null;
+            next = null;
+
+            var exElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+            exElem.Extend(2);
+            exElem[0] = 0x03;
+            exElem[1] = 0x04;
+
+            next = ExaArray1D<byte>.CreateFrom(exElem);
+            Assert.That(next.Length, Is.EqualTo(exElem.Length));
+            Assert.That(next.OptimizationStrategy, Is.EqualTo(exElem.OptimizationStrategy));
+            Assert.That(next.Items(), Is.EquivalentTo(exElem.Items()));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFrom002Objects()
+        {
+            var exPerf = new ExaArray1D<object>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(2);
+            exPerf[0] = new object();
+            exPerf[1] = new object();
+
+            var next = ExaArray1D<object>.CreateFrom(exPerf);
+            Assert.That(next.Length, Is.EqualTo(exPerf.Length));
+            Assert.That(next.OptimizationStrategy, Is.EqualTo(exPerf.OptimizationStrategy));
+            Assert.That(next[0], Is.SameAs(exPerf[0]));
+            Assert.That(next[1], Is.SameAs(exPerf[1]));
+            Assert.That(next[0], Is.Not.SameAs(next[1]));
+
+            exPerf = null;
+            next = null;
+
+            var exElem = new ExaArray1D<object>(Strategy.MAX_ELEMENTS);
+            exElem.Extend(2);
+            exElem[0] = new object();
+            exElem[1] = new object();
+
+            next = ExaArray1D<object>.CreateFrom(exElem);
+            Assert.That(next.Length, Is.EqualTo(exElem.Length));
+            Assert.That(next.OptimizationStrategy, Is.EqualTo(exElem.OptimizationStrategy));
+            Assert.That(next[0], Is.SameAs(exElem[0]));
+            Assert.That(next[1], Is.SameAs(exElem[1]));
+            Assert.That(next[0], Is.Not.SameAs(next[1]));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFrom003()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(5_000_000_000); // more than one chunk
+
+            var next = ExaArray1D<byte>.CreateFrom(exPerf);
+            Assert.That(next.Length, Is.EqualTo(exPerf.Length));
+            Assert.DoesNotThrow(() => { next[4_999_999_999] = 0xab; });
+
+            exPerf = null;
+            next = null;
+
+            var exElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+            exElem.Extend(5_000_000_000);
+
+            next = ExaArray1D<byte>.CreateFrom(exElem);
+            Assert.That(next.Length, Is.EqualTo(exElem.Length));
+            Assert.DoesNotThrow(() => { next[4_999_999_999] = 0xab; });
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFrom004()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            var next = ExaArray1D<byte>.CreateFrom(exPerf);
+            Assert.That(next.Length, Is.EqualTo(0));
+
+            exPerf = null;
+            next = null;
+
+            var exElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+            next = ExaArray1D<byte>.CreateFrom(exElem);
+            Assert.That(next.Length, Is.EqualTo(0));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFrom005Objects()
+        {
+            var exPerf = new ExaArray1D<TestClass>();
+            exPerf.Extend(3);
+            exPerf[0] = new TestClass {Age = 5};
+            exPerf[1] = new TestClass {Age = 10};
+            exPerf[2] = new TestClass {Age = 45};
+
+            var next = ExaArray1D<TestClass>.CreateFrom(exPerf);
+            Assert.That(next.Length, Is.EqualTo(3));
+            Assert.That(next[1].Age, Is.EqualTo(10));
+
+            next[1].Age = 50;
+            Assert.That(next[1].Age, Is.EqualTo(50));
+            Assert.That(exPerf[1].Age, Is.EqualTo(50));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange001()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(3);
+            exPerf[0] = 0x01;
+            exPerf[1] = 0x02;
+            exPerf[2] = 0x03;
+
+            var next = ExaArray1D<byte>.CreateFrom(exPerf, 0, 1);
+            Assert.That(next.Length, Is.EqualTo(2));
+            Assert.That(next[0], Is.EqualTo(exPerf[0]));
+            Assert.That(next[1], Is.EqualTo(exPerf[1]));
+            Assert.That(next.OptimizationStrategy, Is.EqualTo(exPerf.OptimizationStrategy));
+
+            exPerf = null;
+            next = null;
+
+            var exElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+            exElem.Extend(3);
+            exElem[0] = 0x01;
+            exElem[1] = 0x02;
+            exElem[2] = 0x03;
+
+            next = ExaArray1D<byte>.CreateFrom(exElem, 1, 2);
+            Assert.That(next.Length, Is.EqualTo(2));
+            Assert.That(next[0], Is.EqualTo(exElem[1]));
+            Assert.That(next[1], Is.EqualTo(exElem[2]));
+            Assert.That(next.OptimizationStrategy, Is.EqualTo(exElem.OptimizationStrategy));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange002()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(3);
+            exPerf[0] = 0x01;
+            exPerf[1] = 0x02;
+            exPerf[2] = 0x03;
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var next = ExaArray1D<byte>.CreateFrom(exPerf, 100, 200);
+            });
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange003()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(3);
+            exPerf[0] = 0x01;
+            exPerf[1] = 0x02;
+            exPerf[2] = 0x03;
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var next = ExaArray1D<byte>.CreateFrom(exPerf, 0, 200);
+            });
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange004()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(3);
+            exPerf[0] = 0x01;
+            exPerf[1] = 0x02;
+            exPerf[2] = 0x03;
+
+            Assert.Throws<IndexOutOfRangeException>(() =>
+            {
+                var next = ExaArray1D<byte>.CreateFrom(exPerf, 200, 100);
+            });
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange005()
+        {
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+            exPerf.Extend(3);
+            exPerf[0] = 0x01;
+            exPerf[1] = 0x02;
+            exPerf[2] = 0x03;
+
+            var next = ExaArray1D<byte>.CreateFrom(exPerf, 2, 2);
+            Assert.That(next.Length, Is.EqualTo(1));
+            Assert.That(next.OptimizationStrategy, Is.EqualTo(Strategy.MAX_ELEMENTS));
+            Assert.That(next[0], Is.EqualTo(exPerf[2]));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange006Objects()
+        {
+            var exPerf = new ExaArray1D<TestClass>();
+            exPerf.Extend(3);
+            exPerf[0] = new TestClass {Age = 5};
+            exPerf[1] = new TestClass {Age = 10};
+            exPerf[2] = new TestClass {Age = 45};
+
+            var next = ExaArray1D<TestClass>.CreateFrom(exPerf, 2, 2);
+            Assert.That(next.Length, Is.EqualTo(1));
+            Assert.That(next[0].Age, Is.EqualTo(45));
+
+            next[0].Age = 50;
+            Assert.That(next[0].Age, Is.EqualTo(50));
+            Assert.That(exPerf[2].Age, Is.EqualTo(50));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange007()
+        {
+            const uint MAX = 1_073_741_824;
+
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(MAX + 3); // more than one chunk
+            exPerf[MAX - 1 + 2] = 0x01;
+            exPerf[MAX - 1 + 1] = 0x02;
+            exPerf[MAX - 1 - 0] = 0x03;
+            exPerf[MAX - 1 - 1] = 0x04;
+            exPerf[MAX - 1 - 2] = 0x05;
+            exPerf[MAX - 1 - 3] = 0x06;
+            exPerf[MAX - 1 - 4] = 0x07;
+
+            var next = ExaArray1D<byte>.CreateFrom(exPerf, MAX - 1 - 2, MAX - 1 + 2);
+            Assert.That(next.Length, Is.EqualTo(5));
+            Assert.That(next[0], Is.EqualTo(exPerf[MAX - 1 - 2]));
+            Assert.That(next[1], Is.EqualTo(exPerf[MAX - 1 - 1]));
+            Assert.That(next[2], Is.EqualTo(exPerf[MAX - 1 - 0]));
+            Assert.That(next[3], Is.EqualTo(exPerf[MAX - 1 + 1]));
+            Assert.That(next[4], Is.EqualTo(exPerf[MAX - 1 + 2]));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange008()
+        {
+            const uint MAX = 1_073_741_824;
+
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(3 * MAX + 3); // more than one chunk
+            exPerf[MAX - 1 + 2] = 0x01;
+            exPerf[MAX - 1 + 1] = 0x02;
+            exPerf[MAX - 1 - 0] = 0x03;
+            exPerf[MAX - 1 - 1] = 0x04;
+            exPerf[MAX - 1 - 2] = 0x05;
+            exPerf[MAX - 1 - 3] = 0x06;
+            exPerf[MAX - 1 - 4] = 0x07;
+
+            var next = ExaArray1D<byte>.CreateFrom(exPerf, MAX - 1 - 2, MAX - 1 + 2);
+            Assert.That(next.Length, Is.EqualTo(5));
+            Assert.That(next[0], Is.EqualTo(exPerf[MAX - 1 - 2]));
+            Assert.That(next[1], Is.EqualTo(exPerf[MAX - 1 - 1]));
+            Assert.That(next[2], Is.EqualTo(exPerf[MAX - 1 - 0]));
+            Assert.That(next[3], Is.EqualTo(exPerf[MAX - 1 + 1]));
+            Assert.That(next[4], Is.EqualTo(exPerf[MAX - 1 + 2]));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange009()
+        {
+            const uint MAX = 1_073_741_824;
+
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(3 * MAX + 3); // more than one chunk
+            exPerf[100_000_000] = 0xFF;
+            exPerf[3 * MAX - 1 + 2] = 0x01;
+            exPerf[3 * MAX - 1 + 1] = 0x02;
+            exPerf[3 * MAX - 1 - 0] = 0x03;
+            exPerf[3 * MAX - 1 - 1] = 0x04;
+            exPerf[3 * MAX - 1 - 2] = 0x05;
+            exPerf[3 * MAX - 1 - 3] = 0x06;
+            exPerf[3 * MAX - 1 - 4] = 0x07;
+
+            var next = ExaArray1D<byte>.CreateFrom(exPerf, 100_000_000, 3 * MAX - 1 + 2);
+            Assert.That(next.Length, Is.EqualTo(exPerf.Length - 100_000_000 - 1));
+            Assert.That(next[0], Is.EqualTo(0xFF));
+
+            Assert.That(next[next.Length - 1 - 4], Is.EqualTo(exPerf[3 * MAX - 1 - 2]));
+            Assert.That(next[next.Length - 1 - 3], Is.EqualTo(exPerf[3 * MAX - 1 - 1]));
+            Assert.That(next[next.Length - 1 - 2], Is.EqualTo(exPerf[3 * MAX - 1 - 0]));
+            Assert.That(next[next.Length - 1 - 1], Is.EqualTo(exPerf[3 * MAX - 1 + 1]));
+            Assert.That(next[next.Length - 1 - 0], Is.EqualTo(exPerf[3 * MAX - 1 + 2]));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromRange010()
+        {
+            const uint MAX = 1_073_741_824;
+
+            var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+            exPerf.Extend(3 * MAX); // more than one chunk
+
+            var next1 = ExaArray1D<byte>.CreateFrom(exPerf, 0, exPerf.Length - 1);
+            var next2 = exPerf.Clone();
+            var next3 = exPerf.Clone(0, exPerf.Length - 1);
+            var next4 = exPerf[0, exPerf.Length - 1];
+
+            Assert.That(next1.Length, Is.EqualTo(exPerf.Length));
+            Assert.That(next2.Length, Is.EqualTo(exPerf.Length));
+            Assert.That(next3.Length, Is.EqualTo(exPerf.Length));
+            Assert.That(next4.Length, Is.EqualTo(exPerf.Length));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromSequence001()
+        {
+            var list = new List<int>
+            {
+                5,
+                7,
+                8,
+                10,
+                16,
+            };
+
+            var exPerf1 = list.AsExaArray();
+            Assert.That(exPerf1.OptimizationStrategy, Is.EqualTo(Strategy.MAX_PERFORMANCE));
+            Assert.That(exPerf1.Length, Is.EqualTo(list.Count));
+            Assert.That(exPerf1.Items(), Is.EquivalentTo(list));
+
+            var exPerf2 = list.AsExaArray(Strategy.MAX_ELEMENTS);
+            Assert.That(exPerf2.OptimizationStrategy, Is.EqualTo(Strategy.MAX_ELEMENTS));
+            Assert.That(exPerf2.Length, Is.EqualTo(list.Count));
+            Assert.That(exPerf2.Items(), Is.EquivalentTo(list));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromSequence002()
+        {
+            var array = new int[]
+            {
+                5,
+                7,
+                8,
+                10,
+                16,
+            };
+
+            var exPerf1 = array.AsExaArray();
+            Assert.That(exPerf1.OptimizationStrategy, Is.EqualTo(Strategy.MAX_PERFORMANCE));
+            Assert.That(exPerf1.Length, Is.EqualTo(array.Length));
+            Assert.That(exPerf1.Items(), Is.EquivalentTo(array));
+
+            var exPerf2 = array.AsExaArray(Strategy.MAX_ELEMENTS);
+            Assert.That(exPerf2.OptimizationStrategy, Is.EqualTo(Strategy.MAX_ELEMENTS));
+            Assert.That(exPerf2.Length, Is.EqualTo(array.Length));
+            Assert.That(exPerf2.Items(), Is.EquivalentTo(array));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromSequence003()
+        {
+            var list = new List<int>
+            {
+                5,
+                7,
+                8,
+                10,
+                16,
+            };
+
+            var exPerf1 = list.AsEnumerable().AsExaArray();
+            Assert.That(exPerf1.OptimizationStrategy, Is.EqualTo(Strategy.MAX_PERFORMANCE));
+            Assert.That(exPerf1.Length, Is.EqualTo(list.Count));
+            Assert.That(exPerf1.Items(), Is.EquivalentTo(list));
+
+            var exPerf2 = list.AsEnumerable().AsExaArray(Strategy.MAX_ELEMENTS);
+            Assert.That(exPerf2.OptimizationStrategy, Is.EqualTo(Strategy.MAX_ELEMENTS));
+            Assert.That(exPerf2.Length, Is.EqualTo(list.Count));
+            Assert.That(exPerf2.Items(), Is.EquivalentTo(list));
+        }
+
+        [Test]
+        [Category("normal")]
+        [Category("cover")]
+        public void CreateFromSequence004()
+        {
+            var list = new List<int>
+            {
+                5,
+                7,
+                8,
+                10,
+                16,
+            };
+
+            var exPerf1 = list.AsEnumerable().AsExaArray((ulong) list.Count);
+            Assert.That(exPerf1.OptimizationStrategy, Is.EqualTo(Strategy.MAX_PERFORMANCE));
+            Assert.That(exPerf1.Length, Is.EqualTo(list.Count));
+            Assert.That(exPerf1.Items(), Is.EquivalentTo(list));
+
+            var exPerf2 = list.AsEnumerable().AsExaArray((ulong) list.Count, Strategy.MAX_ELEMENTS);
+            Assert.That(exPerf2.OptimizationStrategy, Is.EqualTo(Strategy.MAX_ELEMENTS));
+            Assert.That(exPerf2.Length, Is.EqualTo(list.Count));
+            Assert.That(exPerf2.Items(), Is.EquivalentTo(list));
+
+            var exPerf3 = list.AsEnumerable().AsExaArray(3);
+            Assert.That(exPerf3.OptimizationStrategy, Is.EqualTo(Strategy.MAX_PERFORMANCE));
+            Assert.That(exPerf3.Length, Is.EqualTo(3));
+            Assert.That(exPerf3.Items(), Is.EquivalentTo(new int[] {5, 7, 8}));
+        }
+
+        [Test]
+        [Category("intensive")]
         public void Adding5Billion01()
         {
             ulong sum1 = 0;
@@ -86,6 +670,8 @@ namespace ExaArrayTests
         }
 
         [Test]
+        [Category("cover")]
+        [Category("normal")]
         public void Using5Billion01()
         {
             var exaA = new ExaArray1D<byte>();
@@ -94,6 +680,8 @@ namespace ExaArrayTests
         }
 
         [Test]
+        [Category("cover")]
+        [Category("normal")]
         public void TestStrategies01()
         {
             var exaA = new ExaArray1D<byte>();
@@ -107,6 +695,7 @@ namespace ExaArrayTests
         }
 
         [Test]
+        [Category("performance")]
         public void TestPerformance01()
         {
             var t1Times = new long[10];
@@ -147,6 +736,62 @@ namespace ExaArrayTests
 
             TestContext.WriteLine($"Performing 100M assignments took {t2Times.Average()} ms (average) by means of the max. performance strategy (min={t2Times.Min()} ms, max={t2Times.Max()} ms)");
         }
+        
+        [Test]
+        [Category("cover")]
+        [Category("normal")]
+        public void StoreAndLoad01()
+        {
+            var exaA = new ExaArray1D<byte>();
+            exaA.Extend(5_000_000);
+            exaA[4_483_124] = 0xff;
+
+            var filename = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+            using (var file = File.OpenWrite(filename))
+            {
+                exaA.Store(file);
+            }
+
+            using (var file = File.OpenRead(filename))
+            {
+                var exaB = ExaArray1D<byte>.Restore(file);
+                
+                Assert.That(exaA.Length, Is.EqualTo(exaB.Length));
+                Assert.That(exaA[4_483_124], Is.EqualTo(0xff));
+                Assert.That(exaB[4_483_124], Is.EqualTo(0xff));
+            }
+            
+            File.Delete(filename);
+        }
+        
+        [Test]
+        [Category("cover")]
+        [Category("normal")]
+        public void StoreAndLoad02()
+        {
+            var exaA = new ExaArray1D<TestClass>();
+            exaA.Extend(100);
+            exaA[66] = new TestClass
+            {
+                Age = 55,
+            };
+
+            var filename = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+            using (var file = File.OpenWrite(filename))
+            {
+                exaA.Store(file);
+            }
+
+            using (var file = File.OpenRead(filename))
+            {
+                var exaB = ExaArray1D<TestClass>.Restore(file);
+                
+                Assert.That(exaA.Length, Is.EqualTo(exaB.Length));
+                Assert.That(exaA[66].Age, Is.EqualTo(55));
+                Assert.That(exaB[66].Age, Is.EqualTo(55));
+            }
+            
+            File.Delete(filename);
         }
     }
 }

ExaArrayTests/ExaArray2DTests.cs

@@ -0,0 +1,103 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using Exa;
+using NUnit.Framework;
+
+namespace ExaArrayTests
+{
+    [ExcludeFromCodeCoverage]
+    public class ExaArray2DTests
+    {
+        [Test]
+        [Category("cover")]
+        [Category("normal")]
+        public void CreatingNormalSize01()
+        {
+            var arr = new ExaArray2D<int>();
+            
+            // Empty array must have length = 0:
+            Assert.That(arr.Length, Is.EqualTo(0));
+            
+            // Try to access some points, which should return default(T):
+            Assert.That(arr[0, 0], Is.EqualTo(default(int)));
+            Assert.That(arr[1_000_000, 1_000_000], Is.EqualTo(default(int)));
+            
+            // Even after accessing some points, there should be no space allocated i.e. length is still 0:
+            Assert.That(arr.Length, Is.EqualTo(0));
+
+            // Write an int to a position:
+            arr[500, 500] = 4_756;
+            
+            // Now, we have 500 empty "rows" + 1 "row" with 501 (0-500) elements:
+            Assert.That(arr.Length, Is.EqualTo(501));
+            
+            // Should be possible to read out the value:
+            Assert.That(arr[500, 500], Is.EqualTo(4_756));
+            
+            // Change the value:
+            arr[500, 500] = 100;
+            Assert.That(arr[500, 500], Is.EqualTo(100));
+            
+            // Still the same size:
+            Assert.That(arr.Length, Is.EqualTo(501));
+            
+            // Add another value in the same "row":
+            arr[500, 499] = 499;
+            Assert.That(arr[500, 499], Is.EqualTo(499));
+            Assert.That(arr[500, 500], Is.EqualTo(100));
+            
+            // Now, we should have still 501 elements, because
+            // we added the new value "below" the previously:
+            Assert.That(arr.Length, Is.EqualTo(501));
+            
+            // Add another value in the same "row", but higher:
+            arr[500, 1_000] = 6;
+            Assert.That(arr[500, 499], Is.EqualTo(499));
+            Assert.That(arr[500, 500], Is.EqualTo(100));
+            Assert.That(arr[500, 1_000], Is.EqualTo(6));
+            
+            // Now we should have more elements:
+            Assert.That(arr.Length, Is.EqualTo(1_001));
+        }
+
+        [Test]
+        [Category("cover")]
+        [Category("normal")]
+        public void CreatingHugeSize01()
+        {
+            var arr = new ExaArray2D<int>();
+            arr[0, 1_000_000] = 47;
+            Assert.Throws<ArgumentOutOfRangeException>(() =>
+            {
+                arr[1, UInt64.MaxValue - 1] = 6;
+            });
+        }
+        
+        [Test]
+        [Category("cover")]
+        [Category("normal")]
+        public void StoreAndLoad01()
+        {
+            var exaA = new ExaArray2D<byte>();
+            exaA[5_000_124, 5_000_666] = 0xff;
+
+            var filename = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+            using (var file = File.OpenWrite(filename))
+            {
+                exaA.Store(file);
+            }
+
+            using (var file = File.OpenRead(filename))
+            {
+                var exaB = ExaArray2D<byte>.Restore(file);
+                
+                Assert.That(exaA.Length, Is.EqualTo(exaB.Length));
+                Assert.That(exaA[5_000_124, 5_000_666], Is.EqualTo(0xff));
+                Assert.That(exaB[5_000_124, 5_000_666], Is.EqualTo(0xff));
+            }
+            
+            File.Delete(filename);
+        }
+    }
+}

ExaArrayTests/ExaArrayTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>netcoreapp3.1</TargetFramework>
+        <TargetFramework>net5.0</TargetFramework>
 
         <IsPackable>false</IsPackable>
     </PropertyGroup>

README.md

@@ -1,7 +1,6 @@
 # ExaArray
-ExaArray is a .NET library for exa-scale array-like structures. By using this library, it becomes possible to
-add up to 4.6 quintillion i.e. 4,607,183,514,018,780,000 elements into one array. When using `byte` for `T`,
-this would need approx. 4 EB of memory.
+ExaArray is a .NET library for exa-scale array-like structures. By using this library, it becomes possible to add up to 4.6 quintillion i.e. 4,607,183,514,018,780,000 elements into a one-dimensional array. When using `byte` for `T`, this would need approx. 4 EB of memory. The two-dimensional array can grow up to 18.4 quintillion i.e. 18,446,744,073,709,551,615 elements, though.
 
-Extending the data structure performs as O(n) with O(m+n) of memory. Accessing the data performs as O(1), though.
-For the generic type `T`, any .NET type can be used: The ExaArray uses managed memory.
+Extending the data structure performs as O(n) with O(m+n) of memory. Accessing the data performs as O(1), though. For the generic type `T`, any .NET type can be used: The ExaArray uses managed memory.
+
+Storing to and loading from an arbitrary stream is supported. The data stored in this way should never be part of a public API. Serializing and deserializing is not secure: an attacker can manipulate the data in a targeted manner to compromise the API server, etc.