Implemented more efficient Insert() method for the deque; split RemoveAt() into left-shifting and right-shifting specializations (right-shifting still is a copy of the left-shifting one, will fix it soon); improved unit tests to catch any and all border cases; made the IndexOf() method workable; wrote unit tests for the IndexOf() method; moved removal and insertion functions into the own sub-files to avoid having huge source files

git-svn-id: file:///srv/devel/repo-conversion/nusu@160 d2e56fa2-650e-0410-a79f-9358c0239efd
This commit is contained in:
Markus Ewald 2009-07-13 19:34:27 +00:00
parent ed62fa85f2
commit 58c3254260
6 changed files with 536 additions and 413 deletions

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@ -70,6 +70,12 @@
<DependentUpon>AssertHelper.cs</DependentUpon> <DependentUpon>AssertHelper.cs</DependentUpon>
</Compile> </Compile>
<Compile Include="Source\Collections\Deque.cs" /> <Compile Include="Source\Collections\Deque.cs" />
<Compile Include="Source\Collections\Deque.Insertion.cs">
<DependentUpon>Deque.cs</DependentUpon>
</Compile>
<Compile Include="Source\Collections\Deque.Removal.cs">
<DependentUpon>Deque.cs</DependentUpon>
</Compile>
<Compile Include="Source\Collections\Deque.Test.cs"> <Compile Include="Source\Collections\Deque.Test.cs">
<DependentUpon>Deque.cs</DependentUpon> <DependentUpon>Deque.cs</DependentUpon>
</Compile> </Compile>

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@ -52,6 +52,12 @@
<DependentUpon>AssertHelper.cs</DependentUpon> <DependentUpon>AssertHelper.cs</DependentUpon>
</Compile> </Compile>
<Compile Include="Source\Collections\Deque.cs" /> <Compile Include="Source\Collections\Deque.cs" />
<Compile Include="Source\Collections\Deque.Insertion.cs">
<DependentUpon>Deque.cs</DependentUpon>
</Compile>
<Compile Include="Source\Collections\Deque.Removal.cs">
<DependentUpon>Deque.cs</DependentUpon>
</Compile>
<Compile Include="Source\Collections\Deque.Test.cs"> <Compile Include="Source\Collections\Deque.Test.cs">
<DependentUpon>Deque.cs</DependentUpon> <DependentUpon>Deque.cs</DependentUpon>
</Compile> </Compile>

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@ -0,0 +1,184 @@
using System;
using System.Collections.Generic;
using System.Collections;
namespace Nuclex.Support.Collections {
partial class Deque<ItemType> {
/// <summary>Inserts an item at the beginning of the double-ended queue</summary>
/// <param name="item">Item that will be inserted into the queue</param>
public void AddFirst(ItemType item) {
if(this.firstBlockStartIndex > 0) {
--this.firstBlockStartIndex;
} else { // Need to allocate a new block
this.blocks.Insert(0, new ItemType[this.blockSize]);
this.firstBlockStartIndex = this.blockSize - 1;
}
this.blocks[0][this.firstBlockStartIndex] = item;
++this.count;
}
/// <summary>Appends an item to the end of the double-ended queue</summary>
/// <param name="item">Item that will be appended to the queue</param>
public void AddLast(ItemType item) {
if(this.lastBlockEndIndex < this.blockSize) {
++this.lastBlockEndIndex;
} else { // Need to allocate a new block
this.blocks.Add(new ItemType[this.blockSize]);
this.lastBlockEndIndex = 1;
}
this.blocks[this.blocks.Count - 1][this.lastBlockEndIndex - 1] = item;
++this.count;
}
/// <summary>Inserts the item at the specified index</summary>
/// <param name="index">Index the item will be inserted at</param>
/// <param name="item">Item that will be inserted</param>
public void Insert(int index, ItemType item) {
int distanceToRightEnd = this.count - index;
if(index < distanceToRightEnd) { // Are we closer to the left end?
shiftLeftAndInsert(index, item);
} else { // Nope, we're closer to the right end
shiftRightAndInsert(index, item);
}
}
/// <summary>
/// Shifts all items before the insertion point to the left and inserts
/// the item at the specified index
/// </summary>
/// <param name="index">Index the item will be inserted at</param>
/// <param name="item">Item that will be inserted</param>
private void shiftLeftAndInsert(int index, ItemType item) {
if(index == 0) {
AddFirst(item);
} else {
int blockIndex, subIndex;
findIndex(index, out blockIndex, out subIndex);
int firstBlock = 0;
int blockStart;
// If the first block is full, we need to add another block
if(this.firstBlockStartIndex == 0) {
this.blocks.Insert(0, new ItemType[this.blockSize]);
this.blocks[0][this.blockSize - 1] = this.blocks[1][0];
this.firstBlockStartIndex = this.blockSize - 1;
blockStart = 1;
--subIndex;
if(subIndex < 0) {
subIndex = this.blockSize - 1;
} else {
++blockIndex;
}
++firstBlock;
} else {
blockStart = this.firstBlockStartIndex;
--this.firstBlockStartIndex;
--subIndex;
if(subIndex < 0) {
subIndex = this.blockSize - 1;
--blockIndex;
}
}
// If the insertion point is not in the first block
if(blockIndex != firstBlock) {
Array.Copy(
this.blocks[firstBlock], blockStart,
this.blocks[firstBlock], blockStart - 1,
this.blockSize - blockStart
);
this.blocks[firstBlock][this.blockSize - 1] = this.blocks[firstBlock + 1][0];
// Move all the blocks following the insertion point to the right by one item.
// If there are no blocks inbetween, this for loop will not run.
for(int tempIndex = firstBlock + 1; tempIndex < blockIndex; ++tempIndex) {
Array.Copy(
this.blocks[tempIndex], 1, this.blocks[tempIndex], 0, this.blockSize - 1
);
this.blocks[tempIndex][this.blockSize - 1] = this.blocks[tempIndex + 1][0];
}
blockStart = 1;
}
// Finally, move the items in the block the insertion takes place in
Array.Copy(
this.blocks[blockIndex], blockStart,
this.blocks[blockIndex], blockStart - 1,
subIndex - blockStart + 1
);
this.blocks[blockIndex][subIndex] = item;
++this.count;
}
}
/// <summary>
/// Shifts all items after the insertion point to the right and inserts
/// the item at the specified index
/// </summary>
/// <param name="index">Index the item will be inserted at</param>
/// <param name="item">Item that will be inserted</param>
private void shiftRightAndInsert(int index, ItemType item) {
if(index == this.count) {
AddLast(item);
} else {
int blockIndex, subIndex;
findIndex(index, out blockIndex, out subIndex);
int lastBlock = this.blocks.Count - 1;
int blockLength;
// If the lastmost block is full, we need to add another block
if(this.lastBlockEndIndex == this.blockSize) {
this.blocks.Add(new ItemType[this.blockSize]);
this.blocks[lastBlock + 1][0] = this.blocks[lastBlock][this.blockSize - 1];
this.lastBlockEndIndex = 1;
blockLength = this.blockSize - 1;
} else {
blockLength = this.lastBlockEndIndex;
++this.lastBlockEndIndex;
}
// If the insertion point is not in the lastmost block
if(blockIndex != lastBlock) {
Array.Copy(
this.blocks[lastBlock], 0, this.blocks[lastBlock], 1, blockLength
);
this.blocks[lastBlock][0] = this.blocks[lastBlock - 1][this.blockSize - 1];
// Move all the blocks following the insertion point to the right by one item.
// If there are no blocks inbetween, this for loop will not run.
for(int tempIndex = lastBlock - 1; tempIndex > blockIndex; --tempIndex) {
Array.Copy(
this.blocks[tempIndex], 0, this.blocks[tempIndex], 1, this.blockSize - 1
);
this.blocks[tempIndex][0] = this.blocks[tempIndex - 1][this.blockSize - 1];
}
blockLength = this.blockSize - 1;
}
// Finally, move the items in the block the insertion takes place in
Array.Copy(
this.blocks[blockIndex], subIndex,
this.blocks[blockIndex], subIndex + 1,
blockLength - subIndex
);
this.blocks[blockIndex][subIndex] = item;
++this.count;
}
}
}
} // namespace Nuclex.Support.Collections

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@ -0,0 +1,174 @@
using System;
using System.Collections.Generic;
using System.Collections;
namespace Nuclex.Support.Collections {
partial class Deque<ItemType> {
/// <summary>Removes the first item in the double-ended queue</summary>
public void RemoveFirst() {
if(this.count == 0) {
throw new InvalidOperationException("Cannot remove items from empty deque");
}
// TODO: Zero removed array entry if array is kept
++this.firstBlockStartIndex;
if(this.firstBlockStartIndex >= this.blockSize) { // Block became empty
if(this.count > 1) { // Still more blocks in queue, remove block
this.blocks.RemoveAt(0);
this.firstBlockStartIndex = 0;
} else { // Last block - do not remove
this.firstBlockStartIndex = 0;
this.lastBlockEndIndex = 0;
}
}
--this.count;
}
/// <summary>Removes the last item in the double-ended queue</summary>
public void RemoveLast() {
if(this.count == 0) {
throw new InvalidOperationException("Cannot remove items from empty deque");
}
// TODO: Zero removed array entry if array is kept
--this.lastBlockEndIndex;
if(this.lastBlockEndIndex == 0) { // Block became empty
if(this.count > 1) {
this.blocks.RemoveAt(this.blocks.Count - 1);
this.lastBlockEndIndex = this.blockSize;
} else { // Last block - do not remove
this.firstBlockStartIndex = 0;
this.lastBlockEndIndex = 0;
}
}
--this.count;
}
/// <summary>Removes the item at the specified index</summary>
/// <param name="index">Index of the item that will be removed</param>
public void RemoveAt(int index) {
int distanceToRightEnd = this.count - index;
if(index < distanceToRightEnd) { // Are we closer to the left end?
removeFromLeft(index);
} else { // Nope, we're closer to the right end
removeFromRight(index);
}
}
/// <summary>
/// Removes an item from the left side of the queue by shifting all items that
/// come before it to the right by one
/// </summary>
/// <param name="index">Index of the item that will be removed</param>
private void removeFromLeft(int index) {
if(index == this.count - 1) {
RemoveLast();
} else {
int blockIndex, subIndex;
findIndex(index, out blockIndex, out subIndex);
int lastBlock = this.blocks.Count - 1;
int startIndex;
if(blockIndex < lastBlock) {
Array.Copy(
this.blocks[blockIndex], subIndex + 1,
this.blocks[blockIndex], subIndex,
this.blockSize - subIndex - 1
);
this.blocks[blockIndex][this.blockSize - 1] = this.blocks[blockIndex + 1][0];
for(int tempIndex = blockIndex + 1; tempIndex < lastBlock; ++tempIndex) {
Array.Copy(
this.blocks[tempIndex], 1,
this.blocks[tempIndex], 0,
this.blockSize - 1
);
this.blocks[tempIndex][this.blockSize - 1] = this.blocks[tempIndex + 1][0];
}
startIndex = 0;
} else {
startIndex = subIndex;
}
Array.Copy(
this.blocks[lastBlock], startIndex + 1,
this.blocks[lastBlock], startIndex,
this.lastBlockEndIndex - startIndex - 1
);
if(this.lastBlockEndIndex == 1) {
this.blocks.RemoveAt(lastBlock);
this.lastBlockEndIndex = this.blockSize;
} else {
this.blocks[lastBlock][this.lastBlockEndIndex - 1] = default(ItemType);
--this.lastBlockEndIndex;
}
--this.count;
}
}
/// <summary>
/// Removes an item from the right side of the queue by shifting all items that
/// come after it to the left by one
/// </summary>
/// <param name="index">Index of the item that will be removed</param>
private void removeFromRight(int index) {
if(index == this.count - 1) {
RemoveLast();
} else {
int blockIndex, subIndex;
findIndex(index, out blockIndex, out subIndex);
int lastBlock = this.blocks.Count - 1;
int startIndex;
if(blockIndex < lastBlock) {
Array.Copy(
this.blocks[blockIndex], subIndex + 1,
this.blocks[blockIndex], subIndex,
this.blockSize - subIndex - 1
);
this.blocks[blockIndex][this.blockSize - 1] = this.blocks[blockIndex + 1][0];
for(int tempIndex = blockIndex + 1; tempIndex < lastBlock; ++tempIndex) {
Array.Copy(
this.blocks[tempIndex], 1,
this.blocks[tempIndex], 0,
this.blockSize - 1
);
this.blocks[tempIndex][this.blockSize - 1] = this.blocks[tempIndex + 1][0];
}
startIndex = 0;
} else {
startIndex = subIndex;
}
Array.Copy(
this.blocks[lastBlock], startIndex + 1,
this.blocks[lastBlock], startIndex,
this.lastBlockEndIndex - startIndex - 1
);
if(this.lastBlockEndIndex == 1) {
this.blocks.RemoveAt(lastBlock);
this.lastBlockEndIndex = this.blockSize;
} else {
this.blocks[lastBlock][this.lastBlockEndIndex - 1] = default(ItemType);
--this.lastBlockEndIndex;
}
--this.count;
}
}
}
} // namespace Nuclex.Support.Collections

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@ -28,8 +28,6 @@ using NMock2;
namespace Nuclex.Support.Collections { namespace Nuclex.Support.Collections {
#if true
/// <summary>Unit Test for the double ended queue</summary> /// <summary>Unit Test for the double ended queue</summary>
[TestFixture] [TestFixture]
public class DequeTest { public class DequeTest {
@ -94,6 +92,111 @@ namespace Nuclex.Support.Collections {
} }
} }
/// <summary>Verifies that the Insert() method works in all cases</summary>
/// <remarks>
/// We have several different cases here that will be tested. The deque can
/// shift items to the left or right (depending on which end is closer to
/// the insertion point) and the insertion point may fall in an only partially
/// occupied block, requiring elaborate index calculations
/// </remarks>
[Test]
public void TestInsert() {
for(int testedIndex = 0; testedIndex <= 96; ++testedIndex) {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 96; ++item) {
intDeque.AddLast(item);
}
intDeque.Insert(testedIndex, 12345);
Assert.AreEqual(97, intDeque.Count);
for(int index = 0; index < testedIndex; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
Assert.AreEqual(12345, intDeque[testedIndex]);
for(int index = testedIndex + 1; index < 97; ++index) {
Assert.AreEqual(index - 1, intDeque[index]);
}
}
}
/// <summary>Verifies that the Insert() method works in all cases</summary>
[Test]
public void TestInsertNonNormalized() {
for(int testedIndex = 0; testedIndex <= 96; ++testedIndex) {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 4; item < 96; ++item) {
intDeque.AddLast(item);
}
intDeque.AddFirst(3);
intDeque.AddFirst(2);
intDeque.AddFirst(1);
intDeque.AddFirst(0);
intDeque.Insert(testedIndex, 12345);
Assert.AreEqual(97, intDeque.Count);
for(int index = 0; index < testedIndex; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
Assert.AreEqual(12345, intDeque[testedIndex]);
for(int index = testedIndex + 1; index < 97; ++index) {
Assert.AreEqual(index - 1, intDeque[index]);
}
}
}
/// <summary>Verifies the the RemoveAt() method works in all cases</summary>
[Test]
public void TestRemoveAt() {
for(int testedIndex = 0; testedIndex < 96; ++testedIndex) {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 96; ++item) {
intDeque.AddLast(item);
}
intDeque.RemoveAt(testedIndex);
Assert.AreEqual(95, intDeque.Count);
for(int index = 0; index < testedIndex; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
for(int index = testedIndex; index < 95; ++index) {
Assert.AreEqual(index + 1, intDeque[index]);
}
}
}
/// <summary>Verifies the the RemoveAt() method works in all cases</summary>
[Test]
public void TestRemoveAtNonNormalized() {
for(int testedIndex = 0; testedIndex < 96; ++testedIndex) {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 4; item < 96; ++item) {
intDeque.AddLast(item);
}
intDeque.AddFirst(3);
intDeque.AddFirst(2);
intDeque.AddFirst(1);
intDeque.AddFirst(0);
intDeque.RemoveAt(testedIndex);
Assert.AreEqual(95, intDeque.Count);
for(int index = 0; index < testedIndex; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
for(int index = testedIndex; index < 95; ++index) {
Assert.AreEqual(index + 1, intDeque[index]);
}
}
}
/// <summary> /// <summary>
/// Validates that an exception is thrown if the 'First' property is accessed /// Validates that an exception is thrown if the 'First' property is accessed
/// in an empty deque /// in an empty deque
@ -142,177 +245,6 @@ namespace Nuclex.Support.Collections {
); );
} }
/// <summary>
/// Tests whether the Insert() method of the deque can insert an item at
/// the end of the deque
/// </summary>
[Test]
public void TestInsertAtEnd() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 48; ++item) {
intDeque.AddLast(item);
}
intDeque.Insert(intDeque.Count, 12345);
Assert.AreEqual(12345, intDeque.Last);
}
/// <summary>
/// Tests whether the Insert() method of the deque can insert an item into
/// the last block of the deque when that last block is already full
/// </summary>
[Test]
public void TestInsertInLastBlock() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 48; ++item) {
intDeque.AddLast(item);
}
intDeque.Insert(45, 12345);
Assert.AreEqual(49, intDeque.Count);
for(int index = 0; index < 44; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
Assert.AreEqual(12345, intDeque[45]);
for(int index = 46; index < 49; ++index) {
Assert.AreEqual(index - 1, intDeque[index]);
}
}
/// <summary>
/// Tests whether the Insert() method of the deque can insert an item into
/// the second-to-last block of the deque
/// </summary>
[Test]
public void TestInsertInSecondToLastBlock() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 40; ++item) {
intDeque.AddLast(item);
}
intDeque.Insert(24, 12345);
Assert.AreEqual(41, intDeque.Count);
for(int index = 0; index < 24; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
Assert.AreEqual(12345, intDeque[24]);
for(int index = 25; index < 41; ++index) {
Assert.AreEqual(index - 1, intDeque[index]);
}
}
/// <summary>
/// Tests whether the Insert() method of the deque can insert an item into
/// the third-to-last block of the deque
/// </summary>
[Test]
public void TestInsertInThirdToLastBlock() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 40; ++item) {
intDeque.AddLast(item);
}
intDeque.Insert(8, 12345);
Assert.AreEqual(41, intDeque.Count);
for(int index = 0; index < 8; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
Assert.AreEqual(12345, intDeque[8]);
for(int index = 9; index < 41; ++index) {
Assert.AreEqual(index - 1, intDeque[index]);
}
}
/// <summary>
/// Tests whether the RemoveAt() method of the deque can remove an item from
/// the end of the deque
/// </summary>
[Test]
public void TestRemoveAtEnd() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 48; ++item) {
intDeque.AddLast(item);
}
intDeque.RemoveAt(intDeque.Count - 1);
Assert.AreEqual(46, intDeque.Last);
}
/// <summary>
/// Tests whether the RemoveAt() method of the deque can remove an item
/// from the last block of the deque
/// </summary>
[Test]
public void TestRemoveFromLastBlock() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 48; ++item) {
intDeque.AddLast(item);
}
intDeque.RemoveAt(45);
Assert.AreEqual(47, intDeque.Count);
for(int index = 0; index < 45; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
for(int index = 45; index < 47; ++index) {
Assert.AreEqual(index + 1, intDeque[index]);
}
}
/// <summary>
/// Tests whether the RemoveAt() method of the deque can remove an item from
/// the second-to-last block of the deque
/// </summary>
[Test]
public void TestRemoveFromSecondToLastBlock() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 40; ++item) {
intDeque.AddLast(item);
}
intDeque.RemoveAt(24);
Assert.AreEqual(39, intDeque.Count);
for(int index = 0; index < 24; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
for(int index = 24; index < 39; ++index) {
Assert.AreEqual(index + 1, intDeque[index]);
}
}
/// <summary>
/// Tests whether the RemoveAt() method of the deque can remove an item from
/// the third-to-last block of the deque
/// </summary>
[Test]
public void TestRemoveFromThirdToLastBlock() {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 0; item < 33; ++item) {
intDeque.AddLast(item);
}
intDeque.RemoveAt(8);
Assert.AreEqual(32, intDeque.Count);
for(int index = 0; index < 8; ++index) {
Assert.AreEqual(index, intDeque[index]);
}
for(int index = 8; index < 32; ++index) {
Assert.AreEqual(index + 1, intDeque[index]);
}
}
/// <summary> /// <summary>
/// Verifies that items can be assigned by their index /// Verifies that items can be assigned by their index
/// </summary> /// </summary>
@ -349,9 +281,23 @@ namespace Nuclex.Support.Collections {
); );
} }
/// <summary>Tests the IndexOf() method</summary>
[Test, TestCase(0), TestCase(16), TestCase(32), TestCase(48)]
public void TestIndexOf(int count) {
Deque<int> intDeque = new Deque<int>(16);
for(int item = 4; item < count; ++item) {
intDeque.AddLast(item);
}
if(count > 3) { intDeque.AddFirst(3); }
if(count > 2) { intDeque.AddFirst(2); }
if(count > 1) { intDeque.AddFirst(1); }
if(count > 0) { intDeque.AddFirst(0); }
Assert.AreEqual(count - 1, intDeque.IndexOf(count - 1));
Assert.AreEqual(-1, intDeque.IndexOf(count));
} }
#endif }
} // namespace Nuclex.Support.Collections } // namespace Nuclex.Support.Collections

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@ -4,8 +4,6 @@ using System.Collections;
namespace Nuclex.Support.Collections { namespace Nuclex.Support.Collections {
#if true
/// <summary>A double-ended queue that allocates memory in blocks</summary> /// <summary>A double-ended queue that allocates memory in blocks</summary>
/// <typeparam name="ItemType">Type of the items being stored in the queue</typeparam> /// <typeparam name="ItemType">Type of the items being stored in the queue</typeparam>
/// <remarks> /// <remarks>
@ -20,7 +18,7 @@ namespace Nuclex.Support.Collections {
/// require items to be copied around and still can be accessed by index. /// require items to be copied around and still can be accessed by index.
/// </para> /// </para>
/// </remarks> /// </remarks>
public class Deque<ItemType> /*: IList<ItemType>, IList*/ { public partial class Deque<ItemType> /*: IList<ItemType>, IList*/ {
/// <summary>Initializes a new deque</summary> /// <summary>Initializes a new deque</summary>
public Deque() : this(512) { } public Deque() : this(512) { }
@ -77,202 +75,16 @@ namespace Nuclex.Support.Collections {
} }
} }
/// <summary>Removes the first item in the double-ended queue</summary> /// <summary>
public void RemoveFirst() { /// Determines the index of the first occurence of the specified item in the deque
if(this.count == 0) { /// </summary>
throw new InvalidOperationException("Cannot remove items from empty deque"); /// <param name="item">Item that will be located in the deque</param>
} /// <returns>The index of the item or -1 if it wasn't found</returns>
// TODO: Zero removed array entry if array is kept
++this.firstBlockStartIndex;
if(this.firstBlockStartIndex >= this.blockSize) { // Block became empty
if(this.count > 1) { // Still more blocks in queue, remove block
this.blocks.RemoveAt(0);
this.firstBlockStartIndex = 0;
} else { // Last block - do not remove
this.firstBlockStartIndex = 0;
this.lastBlockEndIndex = 0;
}
}
--this.count;
}
/// <summary>Removes the last item in the double-ended queue</summary>
public void RemoveLast() {
if(this.count == 0) {
throw new InvalidOperationException("Cannot remove items from empty deque");
}
// TODO: Zero removed array entry if array is kept
--this.lastBlockEndIndex;
if(this.lastBlockEndIndex == 0) { // Block became empty
if(this.count > 1) {
this.blocks.RemoveAt(this.blocks.Count - 1);
this.lastBlockEndIndex = this.blockSize;
} else { // Last block - do not remove
this.firstBlockStartIndex = 0;
this.lastBlockEndIndex = 0;
}
}
--this.count;
}
/// <summary>Inserts an item at the beginning of the double-ended queue</summary>
/// <param name="item">Item that will be inserted into the queue</param>
public void AddFirst(ItemType item) {
if(this.firstBlockStartIndex > 0) {
--this.firstBlockStartIndex;
} else { // Need to allocate a new block
this.blocks.Insert(0, new ItemType[this.blockSize]);
this.firstBlockStartIndex = this.blockSize - 1;
}
this.blocks[0][this.firstBlockStartIndex] = item;
++this.count;
}
/// <summary>Appends an item to the end of the double-ended queue</summary>
/// <param name="item">Item that will be appended to the queue</param>
public void AddLast(ItemType item) {
if(this.lastBlockEndIndex < this.blockSize) {
++this.lastBlockEndIndex;
} else { // Need to allocate a new block
this.blocks.Add(new ItemType[this.blockSize]);
this.lastBlockEndIndex = 1;
}
this.blocks[this.blocks.Count - 1][this.lastBlockEndIndex - 1] = item;
++this.count;
}
/// <summary>Inserts the item at the specified index</summary>
/// <param name="index">Index the item will be inserted at</param>
/// <param name="item">Item that will be inserted</param>
public void Insert(int index, ItemType item) {
// TODO: Not perfect. Can shift to left or to right in a deque.
// Rewrite!
if(index == this.count) {
AddLast(item);
} else {
int blockIndex, subIndex;
findIndex(index, out blockIndex, out subIndex);
int lastBlock = this.blocks.Count - 1;
int blockLength;
// If the lastmost block is full, we need to add another block
if(this.lastBlockEndIndex == this.blockSize) {
this.blocks.Add(new ItemType[this.blockSize]);
this.blocks[lastBlock + 1][0] = this.blocks[lastBlock][this.blockSize - 1];
this.lastBlockEndIndex = 1;
blockLength = this.blockSize - 1;
} else {
blockLength = this.lastBlockEndIndex;
++this.lastBlockEndIndex;
}
// If the insertion point is not in the lastmost block
if(blockIndex != lastBlock) {
Array.Copy(
this.blocks[lastBlock], 0, this.blocks[lastBlock], 1, blockLength
);
this.blocks[lastBlock][0] = this.blocks[lastBlock - 1][this.blockSize - 1];
// Move all the blocks following the insertion point to the right by one item.
// If there are no blocks inbetween, this for loop will not run.
for(int tempIndex = lastBlock - 1; tempIndex > blockIndex; --tempIndex) {
Array.Copy(
this.blocks[tempIndex], 0, this.blocks[tempIndex], 1, this.blockSize - 1
);
this.blocks[tempIndex][0] = this.blocks[tempIndex - 1][this.blockSize - 1];
}
blockLength = this.blockSize - 1;
}
// Finally, move the items in the block the insertion takes place in
Array.Copy(
this.blocks[blockIndex], subIndex,
this.blocks[blockIndex], subIndex + 1,
blockLength - subIndex
);
this.blocks[blockIndex][subIndex] = item;
++this.count;
}
}
/// <summary>Removes the item at the specified index</summary>
/// <param name="index">Index of the item that will be removed</param>
public void RemoveAt(int index) {
// TODO: Not perfect. Can shift to left or to right in a deque.
// Rewrite!
if(index == this.count - 1) {
RemoveLast();
} else {
int blockIndex, subIndex;
findIndex(index, out blockIndex, out subIndex);
int lastBlock = this.blocks.Count - 1;
int startIndex;
if(blockIndex < lastBlock) {
Array.Copy(
this.blocks[blockIndex], subIndex + 1,
this.blocks[blockIndex], subIndex,
this.blockSize - subIndex - 1
);
this.blocks[blockIndex][this.blockSize - 1] = this.blocks[blockIndex + 1][0];
for(int tempIndex = blockIndex + 1; tempIndex < lastBlock; ++tempIndex) {
Array.Copy(
this.blocks[tempIndex], 1,
this.blocks[tempIndex], 0,
this.blockSize - 1
);
this.blocks[tempIndex][this.blockSize - 1] = this.blocks[tempIndex + 1][0];
}
startIndex = 0;
} else {
startIndex = subIndex;
}
Array.Copy(
this.blocks[lastBlock], startIndex + 1,
this.blocks[lastBlock], startIndex,
this.lastBlockEndIndex - startIndex - 1
);
if(this.lastBlockEndIndex == 1) {
this.blocks.RemoveAt(lastBlock);
this.lastBlockEndIndex = this.blockSize;
} else {
this.blocks[lastBlock][this.lastBlockEndIndex - 1] = default(ItemType);
--this.lastBlockEndIndex;
}
--this.count;
}
}
/*
public int IndexOf(ItemType item) { public int IndexOf(ItemType item) {
switch(this.blocks.Count) { if(this.blocks.Count == 1) { // Only one block to scan?
int length = this.lastBlockEndIndex - this.firstBlockStartIndex;
// No block exist, so the item cannot be found
case 0: {
return -1;
}
// Only one block exists, start index and end index apply to the same block
case 1: {
int count = this.lastBlockEndIndex - this.firstBlockStartIndex;
int index = Array.IndexOf<ItemType>( int index = Array.IndexOf<ItemType>(
this.blocks[0], item, this.firstBlockStartIndex, count this.blocks[0], item, this.firstBlockStartIndex, length
); );
// If we found something, we need to adjust its index so the first item in // If we found something, we need to adjust its index so the first item in
@ -282,15 +94,12 @@ namespace Nuclex.Support.Collections {
} else { } else {
return -1; return -1;
} }
} } else { // At least two blocks exist
// Two blocks exist, start index is in first block, end index in second block
case 2: {
// Scan the first block for the item and if found, return the index // Scan the first block for the item and if found, return the index
int count = this.blockSize - this.firstBlockStartIndex; int length = this.blockSize - this.firstBlockStartIndex;
int index = Array.IndexOf<ItemType>( int index = Array.IndexOf<ItemType>(
this.blocks[0], item, this.firstBlockStartIndex, this.blockSize this.blocks[0], item, this.firstBlockStartIndex, length
); );
// If we found something, we need to adjust its index // If we found something, we need to adjust its index
@ -298,28 +107,28 @@ namespace Nuclex.Support.Collections {
return (index - this.firstBlockStartIndex); return (index - this.firstBlockStartIndex);
} }
int lastBlock = this.blocks.Count - 1;
for(int tempIndex = 1; tempIndex < lastBlock; ++tempIndex) {
index = Array.IndexOf<ItemType>(
this.blocks[1], item, 0, this.blockSize
);
if(index != -1) {
return (index - this.firstBlockStartIndex + tempIndex * this.blockSize);
}
}
// Nothing found, continue the search in the // Nothing found, continue the search in the
index = Array.IndexOf<ItemType>( index = Array.IndexOf<ItemType>(
this.blocks[1], item, 0, this.lastBlockEndIndex this.blocks[lastBlock], item, 0, this.lastBlockEndIndex
); );
if(index == -1) { if(index == -1) {
return -1; return -1;
} else { } else {
return (index - this.firstBlockStartIndex + this.blockSize); return (index - this.firstBlockStartIndex + lastBlock * this.blockSize);
}
} }
} }
default: {
int count = this.blockSize - this.firstBlockStartIndex;
int index = Array.IndexOf<ItemType>(
this.blocks[0], item, this.firstBlockStartIndex, this.blockSize
);
return -1;
}
}
}
*/
/// <summary>Calculates the block index and local sub index of an entry</summary> /// <summary>Calculates the block index and local sub index of an entry</summary>
/// <param name="index">Index of the entry that will be located</param> /// <param name="index">Index of the entry that will be located</param>
/// <param name="blockIndex">Index of the block the entry is contained in</param> /// <param name="blockIndex">Index of the block the entry is contained in</param>
@ -346,6 +155,4 @@ namespace Nuclex.Support.Collections {
} }
#endif
} // namespace Nuclex.Support.Collections } // namespace Nuclex.Support.Collections