FastExpressionCompiler.LightExpression
4.2.1
Prefix Reserved
dotnet add package FastExpressionCompiler.LightExpression --version 4.2.1
NuGet\Install-Package FastExpressionCompiler.LightExpression -Version 4.2.1
<PackageReference Include="FastExpressionCompiler.LightExpression" Version="4.2.1" />
paket add FastExpressionCompiler.LightExpression --version 4.2.1
#r "nuget: FastExpressionCompiler.LightExpression, 4.2.1"
// Install FastExpressionCompiler.LightExpression as a Cake Addin #addin nuget:?package=FastExpressionCompiler.LightExpression&version=4.2.1 // Install FastExpressionCompiler.LightExpression as a Cake Tool #tool nuget:?package=FastExpressionCompiler.LightExpression&version=4.2.1
FastExpressionCompiler
<img src="./logo.png" alt="logo"/>
Targets .NET 6+, .NET 4.5+, .NET Standard 2.0+
NuGet packages:
The project was originally a part of the DryIoc, so check it out 😉
The problem
ExpressionTree compilation is used by the wide variety of tools, e.g. IoC/DI containers, Serializers, ORMs and OOMs.
But Expression.Compile()
is just slow.
Moreover the compiled delegate may be slower than the manually created delegate because of the reasons:
TL;DR;
Expression.Compile creates a DynamicMethod and associates it with an anonymous assembly to run it in a sand-boxed environment. This makes it safe for a dynamic method to be emitted and executed by partially trusted code but adds some run-time overhead.
See also a deep dive to Delegate internals.
The solution
The FastExpressionCompiler .CompileFast()
extension method is 10-40x times faster than .Compile()
.
The compiled delegate may be in some cases a lot faster than the one produced by .Compile()
.
Note: The actual performance may vary depending on the multiple factors: platform, how complex is expression, does it have a closure, does it contain nested lambdas, etc.
In addition, the memory consumption taken by the compilation will be much smaller (check the Allocated
column in the benchmarks below).
Benchmarks
Updated to .NET 8.0
BenchmarkDotNet v0.13.10, Windows 11 (10.0.22621.2428/22H2/2022Update/SunValley2)
11th Gen Intel Core i7-1185G7 3.00GHz, 1 CPU, 8 logical and 4 physical cores
.NET SDK 8.0.100-rc.2.23502.2
[Host] : .NET 8.0.0 (8.0.23.47906), X64 RyuJIT AVX2
DefaultJob : .NET 8.0.0 (8.0.23.47906), X64 RyuJIT AVX2
Hoisted expression with the constructor and two arguments in closure
var a = new A();
var b = new B();
Expression<Func<X>> e = () => new X(a, b);
Compiling expression:
Method | Mean | Error | StdDev | Median | Ratio | RatioSD | Gen0 | Gen1 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|---|---|
Compile | 121.969 us | 2.4180 us | 5.6040 us | 120.830 us | 35.77 | 2.46 | 0.7324 | - | 4.49 KB | 2.92 |
CompileFast | 3.406 us | 0.0677 us | 0.1820 us | 3.349 us | 1.00 | 0.00 | 0.2441 | 0.2365 | 1.54 KB | 1.00 |
Invoking the compiled delegate (comparing to the direct constructor call):
Method | Mean | Error | StdDev | Median | Ratio | RatioSD | Gen0 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|---|
DirectConstructorCall | 5.734 ns | 0.1501 ns | 0.2745 ns | 5.679 ns | 0.86 | 0.05 | 0.0051 | 32 B | 1.00 |
CompiledLambda | 6.857 ns | 0.1915 ns | 0.5434 ns | 6.704 ns | 1.01 | 0.09 | 0.0051 | 32 B | 1.00 |
FastCompiledLambda | 6.746 ns | 0.1627 ns | 0.1442 ns | 6.751 ns | 1.00 | 0.00 | 0.0051 | 32 B | 1.00 |
Hoisted expression with the static method and two nested lambdas and two arguments in closure
var a = new A();
var b = new B();
Expression<Func<X>> getXExpr = () => CreateX((aa, bb) => new X(aa, bb), new Lazy<A>(() => a), b);
Compiling expression:
Method | Mean | Error | StdDev | Ratio | RatioSD | Gen0 | Gen1 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|---|
Compile | 442.02 us | 8.768 us | 21.998 us | 40.00 | 2.34 | 1.9531 | 0.9766 | 12.04 KB | 2.61 |
CompileFast | 11.06 us | 0.221 us | 0.441 us | 1.00 | 0.00 | 0.7324 | 0.7019 | 4.62 KB | 1.00 |
Invoking compiled delegate comparing to direct method call:
Method | Mean | Error | StdDev | Ratio | RatioSD | Gen0 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|
DirectMethodCall | 35.51 ns | 0.783 ns | 1.308 ns | 0.86 | 0.08 | 0.0267 | 168 B | 1.62 |
Invoke_Compiled | 1,096.15 ns | 21.507 ns | 41.437 ns | 27.15 | 2.75 | 0.0420 | 264 B | 2.54 |
Invoke_CompiledFast | 37.65 ns | 1.466 ns | 4.299 ns | 1.00 | 0.00 | 0.0166 | 104 B | 1.00 |
Manually composed expression with parameters and closure
var a = new A();
var bParamExpr = Expression.Parameter(typeof(B), "b");
var expr = Expression.Lambda(
Expression.New(_ctorX,
Expression.Constant(a, typeof(A)), bParamExpr),
bParamExpr);
Compiling expression:
Method | Mean | Error | StdDev | Median | Ratio | RatioSD | Gen0 | Gen1 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|---|---|
Compile_SystemExpression | 89.076 us | 2.6699 us | 7.6605 us | 85.180 us | 28.12 | 3.05 | 0.7324 | 0.4883 | 4.74 KB | 3.41 |
CompileFast_SystemExpression | 3.138 us | 0.0550 us | 0.0565 us | 3.118 us | 0.99 | 0.03 | 0.2213 | 0.2136 | 1.39 KB | 1.00 |
CompileFast_LightExpression | 3.180 us | 0.0602 us | 0.0591 us | 3.163 us | 1.00 | 0.00 | 0.2213 | 0.2136 | 1.39 KB | 1.00 |
Invoking the compiled delegate compared to the normal delegate and the direct call:
Method | Mean | Error | StdDev | Median | Ratio | RatioSD | Gen0 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|---|
DirectCall | 8.388 ns | 0.2655 ns | 0.7575 ns | 8.092 ns | 1.00 | 0.07 | 0.0051 | 32 B | 1.00 |
Compiled_SystemExpression | 9.474 ns | 0.1870 ns | 0.4105 ns | 9.381 ns | 1.10 | 0.05 | 0.0051 | 32 B | 1.00 |
CompiledFast_SystemExpression | 8.575 ns | 0.1624 ns | 0.1440 ns | 8.517 ns | 1.00 | 0.02 | 0.0051 | 32 B | 1.00 |
CompiledFast_LightExpression | 8.584 ns | 0.0776 ns | 0.0862 ns | 8.594 ns | 1.00 | 0.00 | 0.0051 | 32 B | 1.00 |
FastExpressionCompiler.LightExpression.Expression vs System.Linq.Expressions.Expression
FastExpressionCompiler.LightExpression.Expression
is the lightweight version of System.Linq.Expressions.Expression
.
It is designed to be a drop-in replacement for the System Expression - just install the FastExpressionCompiler.LightExpression package instead of FastExpressionCompiler and replace the usings
using System.Linq.Expressions;
using static System.Linq.Expressions.Expression;
with
using static FastExpressionCompiler.LightExpression.Expression;
namespace FastExpressionCompiler.LightExpression.UnitTests
You may look at it as a bare-bone wrapper for the computation operation node which helps you to compose the computation tree (without messing with the IL emit directly).
It won't validate operations compatibility for the tree the way System.Linq.Expression
does it, and partially why it is so slow.
Hopefully you are checking the expression arguments yourself and not waiting for the Expression
exceptions to blow-up.
Creating the expression:
Method | Mean | Error | StdDev | Ratio | RatioSD | Gen0 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|
Create_SystemExpression | 1,039.5 ns | 20.75 ns | 45.98 ns | 8.29 | 0.50 | 0.2060 | 1304 B | 2.63 |
Create_LightExpression | 125.7 ns | 2.46 ns | 5.99 ns | 1.00 | 0.00 | 0.0789 | 496 B | 1.00 |
Create_LightExpression_with_intrinsics | 130.0 ns | 2.47 ns | 6.25 ns | 1.04 | 0.07 | 0.0777 | 488 B | 0.98 |
Creating and compiling:
Method | Mean | Error | StdDev | Ratio | RatioSD | Gen0 | Gen1 | Allocated | Alloc Ratio |
---|---|---|---|---|---|---|---|---|---|
Create_SystemExpression_and_Compile | 159.184 us | 2.9731 us | 7.1235 us | 37.34 | 1.65 | 0.9766 | 0.4883 | 7.4 KB | 3.06 |
Create_SystemExpression_and_CompileFast | 5.923 us | 0.0996 us | 0.1771 us | 1.34 | 0.05 | 0.5188 | 0.5035 | 3.27 KB | 1.35 |
Create_LightExpression_and_CompileFast | 4.399 us | 0.0484 us | 0.0453 us | 1.00 | 0.00 | 0.3815 | 0.3662 | 2.42 KB | 1.00 |
CreateLightExpression_and_CompileFast_with_intrinsic | 4.384 us | 0.0835 us | 0.0697 us | 1.00 | 0.02 | 0.3815 | 0.3662 | 2.35 KB | 0.97 |
Difference between FastExpressionCompiler and FastExpressionCompiler.LightExpression
FastExpressionCompiler
- Provides the
CompileFast
extension methods for theSystem.Linq.Expressions.LambdaExpression
.
FastExpressionCompiler.LightExpression
- Provides the
CompileFast
extension methods forFastExpressionCompiler.LightExpression.LambdaExpression
. - Provides the drop-in expression replacement with the less consumed memory and the faster construction at the cost of the less validation.
- Includes its own
ExpressionVisitor
. - Supports
ToExpression
method to convert back to theSystem.Linq.Expressions.Expression
.
Both FastExpressionCompiler and FastExpressionCompiler.LightExpression
- Support
ToCSharpString()
method to output the compile-able C# code represented by expression. - Support
ToExpressionString()
method to output the expression construction C# code, so given the expression object you'll get e.g.Expression.Lambda(Expression.New(...))
.
Who's using it
Marten, Rebus, StructureMap, Lamar, ExpressionToCodeLib, NServiceBus, LINQ2DB, MapsterMapper
Considering: Moq, Apex.Serialization
How to use
Install from the NuGet and add the using FastExpressionCompiler;
and replace the call to the .Compile()
with the .CompileFast()
extension method.
Note: CompileFast
has an optional parameter bool ifFastFailedReturnNull = false
to disable fallback to Compile
.
Examples
Hoisted lambda expression (created by the C# Compiler):
var a = new A(); var b = new B();
Expression<Func<X>> expr = () => new X(a, b);
var getX = expr.CompileFast();
var x = getX();
Manually composed lambda expression:
var a = new A();
var bParamExpr = Expression.Parameter(typeof(B), "b");
var expr = Expression.Lambda(
Expression.New(_ctorX,
Expression.Constant(a, typeof(A)), bParamExpr),
bParamExpr);
var f = expr.CompileFast();
var x = f(new B());
Note: You may simplify Expression usage and enable faster refactoring with the C# using static
statement:
using static System.Linq.Expressions.Expression;
// or
// using static FastExpressionCompiler.LightExpression.Expression;
var a = new A();
var bParamExpr = Parameter(typeof(B), "b");
var expr = Lambda(
New(_ctorX, Constant(a, typeof(A)), bParamExpr),
bParamExpr);
var f = expr.CompileFast();
var x = f(new B());
How it works
The idea is to provide the fast compilation for the supported expression types
and fallback to the system Expression.Compile()
for the not supported types:
What's not supported yet
FEC does not support yet:
Quote
Dynamic
RuntimeVariables
DebugInfo
MemberInit
with theMemberMemberBinding
and theListMemberBinding
binding typesNewArrayInit
multi-dimensional array initializer is not supported yet
To find what nodes are not supported in your expression you may use the technic described below in the Diagnostics section.
The compilation is done by traversing the expression nodes and emitting the IL. The code is tuned for the performance and the minimal memory consumption.
The expression is traversed twice:
- 1st round is to collect the constants and nested lambdas into the closure objects.
- 2nd round is to emit the IL code and create the delegate using the
DynamicMethod
.
If visitor finds the not supported expression node or the error condition,
the compilation is aborted, and null
is returned enabling the fallback to System .Compile()
.
Diagnostics and Code Generation
FEC V3 has added powerful diagnostics and code generation tools.
Diagnostics
You may pass the optional CompilerFlags.EnableDelegateDebugInfo
into the CompileFast
methods.
EnableDelegateDebugInfo
adds the diagnostic info into the compiled delegate including its source Expression and C# code.
Can be used as following:
var f = e.CompileFast(true, CompilerFlags.EnableDelegateDebugInfo);
var di = f.Target as IDelegateDebugInfo;
Assert.IsNotNull(di.Expression);
Assert.IsNotNull(di.ExpressionString);
Assert.IsNotNull(di.CSharpString);
ThrowOnNotSupportedExpression and NotSupported_ flags
FEC V3.1 has added the compiler flag CompilerFlags.ThrowOnNotSupportedExpression
.
When passed to CompileFast(flags: CompilerFlags.ThrowOnNotSupportedExpression)
and the expression contains not (yet) supported Expression node the compilation will throw the exception instead of returning null
.
To get the whole list of the not yet supported cases you may check in Result.NotSupported_
enum values.
Code Generation
The Code Generation capabilities are available via the ToCSharpString
and ToExpressionString
extension methods.
Note: When converting the source expression to either C# code or to the Expression construction code you may find
the // NOT_SUPPORTED_EXPRESSION
comments marking the not supported yet expressions by FEC. So you may test the presence or absence of this comment.
Additional optimizations
- Using
FastExpressionCompiler.LightExpression.Expression
instead ofSystem.Linq.Expressions.Expression
for the faster expression creation. - Using
.TryCompileWithPreCreatedClosure
and.TryCompileWithoutClosure
methods when you know the expression at hand and may skip the first traversing round, e.g. for the "static" expression which does not contain the bound constants. Note: You cannot skip the 1st round if the expression contains theBlock
,Try
, orGoto
expressions.
<a target="_blank" href="https://icons8.com/icons/set/bitten-ice-pop">Bitten Ice Pop icon</a> icon by <a target="_blank" href="https://icons8.com">Icons8</a>
Product | Versions Compatible and additional computed target framework versions. |
---|---|
.NET | net5.0 was computed. net5.0-windows was computed. net6.0 is compatible. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 is compatible. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 is compatible. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. |
.NET Core | netcoreapp2.0 was computed. netcoreapp2.1 was computed. netcoreapp2.2 was computed. netcoreapp3.0 was computed. netcoreapp3.1 was computed. |
.NET Standard | netstandard2.0 is compatible. netstandard2.1 is compatible. |
.NET Framework | net461 was computed. net462 was computed. net463 was computed. net47 was computed. net471 was computed. net472 is compatible. net48 was computed. net481 was computed. |
MonoAndroid | monoandroid was computed. |
MonoMac | monomac was computed. |
MonoTouch | monotouch was computed. |
Tizen | tizen40 was computed. tizen60 was computed. |
Xamarin.iOS | xamarinios was computed. |
Xamarin.Mac | xamarinmac was computed. |
Xamarin.TVOS | xamarintvos was computed. |
Xamarin.WatchOS | xamarinwatchos was computed. |
-
.NETFramework 4.7.2
- No dependencies.
-
.NETStandard 2.0
- System.Dynamic.Runtime (>= 4.3.0)
- System.Reflection.Emit.Lightweight (>= 4.7.0)
-
.NETStandard 2.1
- No dependencies.
-
net6.0
- No dependencies.
-
net7.0
- No dependencies.
-
net8.0
- No dependencies.
NuGet packages (5)
Showing the top 5 NuGet packages that depend on FastExpressionCompiler.LightExpression:
Package | Downloads |
---|---|
SecurityLogin.Redis
An security method to login |
|
StirlingLabs.StringToExpression
StringToExpression allows you to create methods that take strings and outputs .NET expressions. It is highly configurable allowing you to define your own language with your own syntax. |
|
Faster.Ioc
Package Description |
|
SecurityLogin.Cache
An security method to login |
|
Orsak.AspNetCore
Package Description |
GitHub repositories
This package is not used by any popular GitHub repositories.
Version | Downloads | Last updated |
---|---|---|
4.2.1 | 576 | 7/2/2024 |
4.2.0 | 1,291 | 4/29/2024 |
4.1.0 | 1,129 | 1/20/2024 |
4.0.1 | 3,643 | 11/23/2023 |
4.0.0 | 160 | 11/12/2023 |
3.4.0-preview-01 | 163 | 8/19/2023 |
3.3.4 | 4,961 | 1/17/2023 |
3.3.3 | 11,292 | 7/24/2022 |
3.3.2 | 939 | 5/27/2022 |
3.3.1 | 492 | 5/25/2022 |
3.3.0 | 54,162 | 4/26/2022 |
3.2.2 | 8,143 | 2/2/2022 |
3.2.1 | 573 | 7/21/2021 |
3.2.0 | 644 | 6/14/2021 |
3.1.0 | 467 | 5/3/2021 |
3.0.5 | 389 | 4/21/2021 |
3.0.4 | 379 | 4/6/2021 |
3.0.3 | 439 | 4/1/2021 |
3.0.2 | 429 | 3/30/2021 |
3.0.1 | 432 | 3/27/2021 |
3.0.0 | 10,292 | 3/17/2021 |
3.0.0-preview-07 | 384 | 12/25/2020 |
3.0.0-preview-06 | 265 | 12/1/2020 |
3.0.0-preview-05 | 874 | 11/27/2020 |
3.0.0-preview-04 | 333 | 11/3/2020 |
3.0.0-preview-03 | 309 | 11/2/2020 |
3.0.0-preview-02 | 600 | 10/23/2020 |
3.0.0-preview-01 | 330 | 10/23/2020 |
2.0.0 | 11,997 | 1/25/2019 |
2.0.0-preview-03 | 602 | 11/9/2018 |
2.0.0-preview-02 | 626 | 10/25/2018 |
2.0.0-preview-01 | 615 | 10/24/2018 |
## v4.2.1 Feature and bug-fix release
- fix: ImTools should disable the nullable context
- fix: nullable property
- fix: Incorrect il for struct indexer
- fix: Fix or support return ref value
- fix: Incorrect il when passing by ref value
## Contributors
* @sebastienros made contribution in https://github.com/dadhi/FastExpressionCompiler/pull/412
## Full Changelog
https://github.com/dadhi/FastExpressionCompiler/compare/v4.2.0...v4.2.1
## v4.2.0 Feature and bug-fix release
- feat: #133 Optimize Switch Expression
- feat: #393 Support ToCSharpString of the block in the ternary expression
- feat: #396 Optimize conditional expressions with the DefaultExpression left or right operand the same way as ConstantExpression
- fix: #390 System.AccessViolationException when mapping using Mapster
- fix: #391 ToCSharpString outputs ? for Nullable which does not produce the compile-able code
- fix: #392 ToExpressionString wrongly declares Label instead of LabelTarget array
- fix: #394 Calling a user defined == operator runs into a CLR invalid program exception
- fix: #397 Fix and optimize the Switch support
- fix: #399 Coalesce nullable with 0 is not working
- fix: #400 Fix the direct assignment of Try to Member expression because indirect assignment through tmp var works
- fix: #401 Invoke inlining is not working with collections in AutoMapper tests
- fix: #404 An expression with a single parameter concatenated to a string causes 'Exception has been thrown by the target of an invocation' during delegate invocation
- fix: #405 NullReferenceException with V4.X when using long?[]
- fix: #406 NullReferenceException with V4.X
- fix: #407 NullReferenceException when setting the Enum field
- fix: #408 Dictionary mapping failing when the InvocationExpression inlining is involved
## v4.0.2 Bug-fix release
- added: #379 Add direct net8.0 target as soon as Appveyor CI will support it
- fixed: #380 Comparisons with nullable types
- fixed: #381 NullReferenceException with V4.X when trying to map
- fixed: #386 Value can not be null(parametr 'meth')
## v4.0.1 Bug-fix release
- fixed: #374 CompileFast doesn't work with HasFlag
## v4.0.0 Major release
- fixed: #352 xxxAssign doesn't work with MemberAccess
- fixed: #353 NullReferenceException when calling CompileFast() results
- fixed: #357 Invalid program exception
- fixed: #366 FastExpressionCompiler[v3.3.4] gives incorrect results in some linq operations
- fixed: #368 Fix duplicate nested lambda compilation
- fixed: #374 CompileFast doesn't work with HasFlag
- added: #264 Optimize the array index emit to emit specific Ldelem_ code instead of generic Ldelem
- added: #273 Implement IArgumentProvider for the BlockExpression to minimize the consumed memory
- added: #346 Is it possible to implement ref local variables?
- added: #359 Improve the performance of variable lookup
- added: #367 Better diagnostics and debugging with error codes from Collect and Compile rounds
- added: #369 Decrease memory occupied by the LightExpression Block by storing Expression in SmallList (partly on stack)
- added: #370 Optimize any nested lambda compilation (LINQ) by compiling right after collect one-by-one
- added: #372 Support LightExpression.Expression.TryConvertDelegateIntrinsic for converting one type of delegate to another
- added: #373 Support custom C# printing for the LightExpression.Expression