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Expression tree cloner can now clone multi-dimensional arrays

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git-svn-id: file:///srv/devel/repo-conversion/nusu@232 d2e56fa2-650e-0410-a79f-9358c0239efd
This commit is contained in:
Markus Ewald 2012-02-04 14:22:59 +00:00
parent 1307976597
commit 79063f59c1
2 changed files with 394 additions and 193 deletions
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30
Source/Cloning/ExpressionTreeCloner.Test.cs
View File

@ -55,6 +55,16 @@ namespace Nuclex.Support.Cloning {
Assert.AreEqual(original.TestProperty, clone.TestProperty);
}
/// <summary>Verifies that shallow clones of arrays can be made</summary>
[Test]
public void PrimitiveArraysCanBeCloned() {
var original = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
int[] clone = this.cloneFactory.DeepClone(original, false);
Assert.AreNotSame(original, clone);
CollectionAssert.AreEqual(original, clone);
}
#if false
/// <summary>Verifies that shallow clones of arrays can be made</summary>
[Test]
@ -66,20 +76,22 @@ namespace Nuclex.Support.Cloning {
Assert.AreSame(original[0], clone[0]);
}
//#endif
#endif
/// <summary>Verifies that deep clones of arrays can be made</summary>
[Test]
public void DeepClonesOfArraysCanBeMade() {
var original = new TestReferenceType[] {
var original = new TestReferenceType[,] {
{
new TestReferenceType() { TestField = 123, TestProperty = 456 }
};
TestReferenceType[] clone = this.cloneFactory.DeepClone(original, false);
Assert.AreNotSame(original[0], clone[0]);
Assert.AreEqual(original[0].TestField, clone[0].TestField);
Assert.AreEqual(original[0].TestProperty, clone[0].TestProperty);
}
//#if false
};
TestReferenceType[,] clone = this.cloneFactory.DeepClone(original, false);
Assert.AreNotSame(original[0, 0], clone[0, 0]);
//Assert.AreEqual(original[0,0].TestField, clone[0,0].TestField);
//Assert.AreEqual(original[0,0].TestProperty, clone[0,0].TestProperty);
}
#if false
/// <summary>Verifies that deep clones of a generic list can be made</summary>
[Test]
public void GenericListsCanBeCloned() {

259
Source/Cloning/ExpressionTreeCloner.cs
View File

@ -134,6 +134,209 @@ namespace Nuclex.Support.Cloning {
}
}
/// <summary>
/// Generates state transfer expressions to copy an array of primitive types
/// </summary>
/// <param name="clonedType">Type of array that will be cloned</param>
/// <param name="original">Variable expression for the original array</param>
/// <param name="variables">Receives variables used by the transfer expressions</param>
/// <param name="transferExpressions">Receives the generated transfer expressions</param>
private static void generatePrimitiveArrayTransferExpressions(
Type clonedType,
ParameterExpression original,
ICollection<ParameterExpression> variables,
ICollection<Expression> transferExpressions
) {
// We need a temporary variable because the IfThen expression is not suitable
// for returning values
ParameterExpression clone = Expression.Variable(clonedType, "clone");
variables.Add(clone);
// If the array referenced by 'original' is not null, call Array.Clone() on it
// and assign the result to our temporary variable
MethodInfo arrayCloneMethodInfo = typeof(Array).GetMethod("Clone");
transferExpressions.Add(
Expression.IfThen(
Expression.NotEqual(original, Expression.Constant(null)),
Expression.Assign(
clone,
Expression.Convert(
Expression.Call(original, arrayCloneMethodInfo),
clonedType
)
)
)
);
// Set the return value to the temporary variable
transferExpressions.Add(clone);
}
/// <summary>
/// Generates state transfer expressions to copy an array of complex types
/// </summary>
/// <param name="clonedType">Type of array that will be cloned</param>
/// <param name="original">Variable expression for the original array</param>
/// <param name="variables">Receives variables used by the transfer expressions</param>
/// <param name="transferExpressions">Receives the generated transfer expressions</param>
private static void generateComplexArrayTransferExpressions(
Type clonedType,
ParameterExpression original,
IList<ParameterExpression> variables,
ICollection<Expression> transferExpressions
) {
// We need a temporary variable because the IfThen expression is not suitable
// for returning values
ParameterExpression clone = Expression.Variable(clonedType, "clone");
variables.Add(clone);
int dimensionCount = clonedType.GetArrayRank();
int baseVariableIndex = variables.Count;
var arrayTransferExpressions = new List<Expression>();
Type elementType = clonedType.GetElementType();
// Retrieve the length of each of the array's dimensions
MethodInfo arrayGetLengthMethodInfo = typeof(Array).GetMethod("GetLength");
for(int index = 0; index < dimensionCount; ++index) {
ParameterExpression length = Expression.Variable(typeof(int));
variables.Add(length);
arrayTransferExpressions.Add(
Expression.Assign(
length,
Expression.Call(original, arrayGetLengthMethodInfo, Expression.Constant(index))
)
);
}
// Create a new array of identical size
switch(dimensionCount) {
case 1: {
MethodInfo arrayCreateInstanceMethodInfo = typeof(Array).GetMethod(
"CreateInstance", new Type[] { typeof(Type), typeof(int) }
);
arrayTransferExpressions.Add(
Expression.Assign(
clone,
Expression.Convert(
Expression.Call(
arrayCreateInstanceMethodInfo,
Expression.Constant(elementType),
variables[baseVariableIndex]
),
clonedType
)
)
);
break;
}
case 2: {
MethodInfo arrayCreateInstanceMethodInfo = typeof(Array).GetMethod(
"CreateInstance", new Type[] { typeof(Type), typeof(int), typeof(int) }
);
arrayTransferExpressions.Add(
Expression.Assign(
clone,
Expression.Convert(
Expression.Call(
arrayCreateInstanceMethodInfo,
Expression.Constant(elementType),
variables[baseVariableIndex],
variables[baseVariableIndex + 1]
),
clonedType
)
)
);
break;
}
case 3: {
MethodInfo arrayCreateInstanceMethodInfo = typeof(Array).GetMethod(
"CreateInstance", new Type[] { typeof(Type), typeof(int), typeof(int), typeof(int) }
);
arrayTransferExpressions.Add(
Expression.Assign(
clone,
Expression.Convert(
Expression.Call(
arrayCreateInstanceMethodInfo,
Expression.Constant(elementType),
variables[baseVariableIndex],
variables[baseVariableIndex + 1],
variables[baseVariableIndex + 2]
),
clonedType
)
)
);
break;
}
default: {
throw new InvalidOperationException("Unsupported array dimension count");
}
}
// Only execute the array transfer expressions if the array is not null
transferExpressions.Add(
Expression.IfThen(
Expression.NotEqual(original, Expression.Constant(null)),
Expression.Block(arrayTransferExpressions)
)
);
// Set the return value to the temporary variable
transferExpressions.Add(clone);
}
/// <summary>Generates state transfer expressions to copy a complex type</summary>
/// <param name="clonedType">Complex type that will be cloned</param>
/// <param name="original">Variable expression for the original instance</param>
/// <param name="variables">Receives variables used by the transfer expressions</param>
/// <param name="transferExpressions">Receives the generated transfer expressions</param>
private static void generateComplexTypeTransferExpressions(
Type clonedType,
ParameterExpression original,
ICollection<ParameterExpression> variables,
ICollection<Expression> transferExpressions
) {
// We need a temporary variable because the IfThen expression is not suitable
// for returning values
ParameterExpression clone = Expression.Variable(clonedType, "clone");
variables.Add(clone);
var complexTransferExpressions = new List<Expression>();
complexTransferExpressions.Add(Expression.Assign(clone, Expression.New(clonedType)));
FieldInfo[] fieldInfos = clonedType.GetFields(
BindingFlags.Public | BindingFlags.NonPublic |
BindingFlags.Instance | BindingFlags.FlattenHierarchy
);
for(int index = 0; index < fieldInfos.Length; ++index) {
FieldInfo fieldInfo = fieldInfos[index];
Type fieldType = fieldInfo.FieldType;
if(fieldType.IsPrimitive) {
complexTransferExpressions.Add(
Expression.Assign(
Expression.Field(clone, fieldInfo),
Expression.Field(original, fieldInfo)
)
);
}
}
transferExpressions.Add(
Expression.IfThen(
Expression.NotEqual(original, Expression.Constant(null)),
Expression.Block(complexTransferExpressions)
)
);
// Set the return value to the temporary variable
transferExpressions.Add(clone);
}
/// <summary>Compiles a method that creates a clone of an object</summary>
/// <typeparam name="TCloned">Type for which a clone method will be created</typeparam>
/// <returns>A method that clones an object of the provided type</returns>
@ -144,55 +347,41 @@ namespace Nuclex.Support.Cloning {
ParameterExpression clone = Expression.Variable(typeof(TCloned), "clone");
var transferExpressions = new List<Expression>();
var variables = new List<ParameterExpression>();
if(clonedType.IsPrimitive || (clonedType == typeof(string))) {
transferExpressions.Add(original); // primitives are copied on assignment
} else if(clonedType.IsArray) {
Type elementType = clonedType.GetElementType();
if(elementType.IsPrimitive || (elementType == typeof(string))) {
MethodInfo arrayCloneMethodInfo = typeof(Array).GetMethod("Clone");
transferExpressions.Add(
Expression.Convert(
Expression.Call(original, arrayCloneMethodInfo),
clonedType
)
generatePrimitiveArrayTransferExpressions(
clonedType, original, variables, transferExpressions
);
} else {
generateComplexArrayTransferExpressions(
clonedType, original, variables, transferExpressions
);
}
} else {
transferExpressions.Add(Expression.Assign(clone, Expression.New(clonedType)));
FieldInfo[] fieldInfos = clonedType.GetFields(
BindingFlags.Public | BindingFlags.NonPublic |
BindingFlags.Instance | BindingFlags.FlattenHierarchy
);
for(int index = 0; index < fieldInfos.Length; ++index) {
FieldInfo fieldInfo = fieldInfos[index];
Type fieldType = fieldInfo.FieldType;
if(fieldType.IsPrimitive) {
transferExpressions.Add(
Expression.Assign(
Expression.Field(clone, fieldInfo),
Expression.Field(original, fieldInfo)
)
generateComplexTypeTransferExpressions(
clonedType, original, variables, transferExpressions
);
}
}
transferExpressions.Add(clone);
}
Expression<Func<TCloned, TCloned>> expression =
Expression.Lambda<Func<TCloned, TCloned>>(
Expression.Block(
new[] { clone },
transferExpressions
),
original
Expression<Func<TCloned, TCloned>> expression;
if(variables.Count > 0) {
expression = Expression.Lambda<Func<TCloned, TCloned>>(
Expression.Block(variables, transferExpressions), original
);
} else if(transferExpressions.Count == 1) {
expression = Expression.Lambda<Func<TCloned, TCloned>>(
transferExpressions[0], original
);
} else {
expression = Expression.Lambda<Func<TCloned, TCloned>>(
Expression.Block(transferExpressions), original
);
}
return expression.Compile();
}