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Merged
egbakou merged 4 commits into from
Feb 14, 2026
Merged

perf: faster base64 size calculation via single span reuse and direct char comparison #6

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bb7b729
perf: avoid memory allocation and mime based string slow issues
egbakou Feb 13, 2026
ccbdfa3
clean up
egbakou Feb 13, 2026
825aec3
refactor: format
egbakou Feb 14, 2026
95d7e27
refactor: format
egbakou Feb 14, 2026
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70 changes: 35 additions & 35 deletions src/FileSizeFromBase64.NET/FileSizeFromBase64.NET.csproj
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Original file line number Diff line number Diff line change
@@ -1,40 +1,40 @@
<Project Sdk="Microsoft.NET.Sdk">

<PropertyGroup>
<TargetFramework>netstandard2.1</TargetFramework>
<AssemblyName>FileSizeFromBase64.NET</AssemblyName>
<RootNamespace>FileSizeFromBase64.NET</RootNamespace>
<GeneratePackageOnBuild>true</GeneratePackageOnBuild>
<Authors>Kodjo Laurent Egbakou</Authors>
<Description>Get file size from base64 string</Description>
<PackageReadmeFile>nuget.md</PackageReadmeFile>
<PackageProjectUrl>https://github.com/lioncoding-oss/FileSizeFromBase64.NET</PackageProjectUrl>
<RepositoryUrl>https://github.com/lioncoding-oss/FileSizeFromBase64.NET</RepositoryUrl>
<PackageIcon>logo.png</PackageIcon>
<Version>2.0.1</Version>
<PackageReleaseNotes>See: https://github.com/lioncoding-oss/FileSizeFromBase64.NET </PackageReleaseNotes>
<PackageTags>FileSize, Base64, Paddings, MIME-type</PackageTags>
<Copyright>Copyright 2026</Copyright>
<PackageLicenseExpression>MIT</PackageLicenseExpression>
<NeutralLanguage>en</NeutralLanguage>
</PropertyGroup>
<PropertyGroup>
<TargetFramework>netstandard2.1</TargetFramework>
<AssemblyName>FileSizeFromBase64.NET</AssemblyName>
<RootNamespace>FileSizeFromBase64.NET</RootNamespace>
<GeneratePackageOnBuild>true</GeneratePackageOnBuild>
<Authors>Kodjo Laurent Egbakou</Authors>
<Description>Get file size from base64 string</Description>
<PackageReadmeFile>nuget.md</PackageReadmeFile>
<PackageProjectUrl>https://github.com/lioncoding-oss/FileSizeFromBase64.NET</PackageProjectUrl>
<RepositoryUrl>https://github.com/lioncoding-oss/FileSizeFromBase64.NET</RepositoryUrl>
<PackageIcon>logo.png</PackageIcon>
<Version>2.0.1</Version>
<PackageReleaseNotes>See: https://github.com/lioncoding-oss/FileSizeFromBase64.NET</PackageReleaseNotes>
<PackageTags>FileSize, Base64, Paddings, MIME-type</PackageTags>
<Copyright>Copyright 2026</Copyright>
<PackageLicenseExpression>MIT</PackageLicenseExpression>
<NeutralLanguage>en</NeutralLanguage>
</PropertyGroup>

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
<OutputPath>bin\Debug</OutputPath>
<DefineConstants>DEBUG</DefineConstants>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
<DebugType>portable</DebugType>
<Optimize>true</Optimize>
<DocumentationFile>bin\Release\FileSizeFromBase64.NET.xml</DocumentationFile>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
<OutputPath>bin\Debug</OutputPath>
<DefineConstants>DEBUG</DefineConstants>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
<DebugType>portable</DebugType>
<Optimize>true</Optimize>
<DocumentationFile>bin\Release\FileSizeFromBase64.NET.xml</DocumentationFile>
</PropertyGroup>

<ItemGroup>
<None Include="..\..\nuget\readme.txt" PackagePath="readme.txt" Pack="true" />
<None Include="..\..\nuget\nuget.md" Pack="true" PackagePath="" />
<None Include="..\..\art\logo.png" Pack="true" PackagePath="" />
</ItemGroup>
<ItemGroup>
<None Include="..\..\nuget\readme.txt" PackagePath="readme.txt" Pack="true"/>
<None Include="..\..\nuget\nuget.md" Pack="true" PackagePath=""/>
<None Include="..\..\art\logo.png" Pack="true" PackagePath=""/>
</ItemGroup>

</Project>
</Project>
49 changes: 19 additions & 30 deletions src/FileSizeFromBase64.NET/FileSizeHelpers.cs
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Expand Up @@ -14,51 +14,40 @@ public static class FileSizeHelpers
/// <param name="applyPaddingsRules">Indicate if the padding management is required or not. Default is false</param>
/// <param name="unitsOfMeasurement">The unit of measure of the file size returned by the method. The default unit of measure is Byte.</param>
/// <returns>The size of the file represented by the base64 string.</returns>
public static double GetFileSizeFromBase64String(string base64String, bool applyPaddingsRules = false, UnitsOfMeasurement unitsOfMeasurement = UnitsOfMeasurement.Byte)
public static double GetFileSizeFromBase64String(
string base64String,
bool applyPaddingsRules = false,
UnitsOfMeasurement unitsOfMeasurement = UnitsOfMeasurement.Byte)
{
if (string.IsNullOrEmpty(base64String)) return 0;
if (string.IsNullOrEmpty(base64String)) return 0d;

var base64Length = base64String
.AsSpan()
[(base64String.IndexOf(',', StringComparison.Ordinal) + 1)..]
.Length;
ReadOnlySpan<char> base64ReadOnlySpan = base64String.AsSpan();

// RFC 2397 https://www.rfc-editor.org/rfc/rfc2397.html data:[<mediatype>][;base64],<data>
if (base64ReadOnlySpan.StartsWith("data:".AsSpan()))
{
var commaIndex = base64String.IndexOf(',');
if (commaIndex >= 0)
base64ReadOnlySpan = base64ReadOnlySpan[(commaIndex + 1)..];
}

var base64Length = base64ReadOnlySpan.Length;

var fileSizeInByte = Math.Ceiling((double)base64Length / 4) * 3;

if (applyPaddingsRules && base64Length >= 2)
{
ReadOnlySpan<char> paddings = base64String.AsSpan()[^2..];
ReadOnlySpan<char> paddings = base64ReadOnlySpan[^2..];

fileSizeInByte = paddings switch
{
_ when paddings.Equals("==", StringComparison.Ordinal) => fileSizeInByte - 2,
_ when paddings[1].Equals('=') => fileSizeInByte - 1,
_ when paddings[0] == '=' && paddings[1] == '=' => fileSizeInByte - 2,
_ when paddings[1] == '=' => fileSizeInByte - 1,
_ => fileSizeInByte
};
}

return fileSizeInByte > 0 ? fileSizeInByte / (int)unitsOfMeasurement : 0;
}
}

/// <summary>
/// Unit of measurement.
/// </summary>
public enum UnitsOfMeasurement
{
/// <summary>
/// B.
/// </summary>
Byte = 1,

/// <summary>
/// KB.
/// </summary>
KiloByte = 1_024,

/// <summary>
/// MB.
/// </summary>
MegaByte = 1_048_576
}
}
22 changes: 22 additions & 0 deletions src/FileSizeFromBase64.NET/UnitsOfMeasurement.cs
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@@ -0,0 +1,22 @@
namespace FileSizeFromBase64.NET;

/// <summary>
/// Unit of measurement.
/// </summary>
public enum UnitsOfMeasurement
{
/// <summary>
/// B.
/// </summary>
Byte = 1,

/// <summary>
/// KB.
/// </summary>
KiloByte = 1_024,

/// <summary>
/// MB.
/// </summary>
MegaByte = 1_048_576
}
36 changes: 20 additions & 16 deletions tests/FileSizeFromBase64.Benchmarks/FileSizeFromBase64.Benchmarks.csproj
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@@ -1,20 +1,24 @@
<Project Sdk="Microsoft.NET.Sdk">

<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net10.0</TargetFramework>
<ImplicitUsings>false</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net10.0</TargetFramework>
<ImplicitUsings>false</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="BenchmarkDotNet" Version="0.13.1" />
<PackageReference Include="FileSizeFromBase64.NET" Version="1.0.0" />
</ItemGroup>
<ItemGroup>
<PackageReference Include="BenchmarkDotNet" Version="0.13.1"/>
</ItemGroup>

<ItemGroup>
<None Update="data.txt">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
</ItemGroup>
</Project>
<ItemGroup>
<None Update="data.txt">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
</ItemGroup>

<ItemGroup>
<ProjectReference Include="..\..\src\FileSizeFromBase64.NET\FileSizeFromBase64.NET.csproj"/>
</ItemGroup>

</Project>
4 changes: 3 additions & 1 deletion tests/FileSizeFromBase64.Benchmarks/FileSizeHelpersBenchmark.cs
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Expand Up @@ -10,7 +10,8 @@

namespace FileSizeFromBase64.Benchmarks;

[Config(typeof(Config))]
[MediumRunJob]
[MemoryDiagnoser]
public class FileSizeHelpersBenchmark
{
private sealed class Config : ManualConfig
Expand All @@ -21,6 +22,7 @@ public Config()

AddJob(baseJob.WithNuGet("FileSizeFromBase64.NET", "1.0.0").WithId("v1.0.0").WithBaseline(true));
AddJob(baseJob.WithNuGet("FileSizeFromBase64.NET", "2.0.0").WithId("v2.0.0"));
AddJob(baseJob.WithNuGet("FileSizeFromBase64.NET", "2.0.1").WithId("v2.0.1"));

AddDiagnoser(MemoryDiagnoser.Default);
SummaryStyle = SummaryStyle.Default.WithRatioStyle(RatioStyle.Percentage);
Expand Down
20 changes: 10 additions & 10 deletions tests/FileSizeFromBase64.NET.ConsoleApp/FileSizeFromBase64.NET.ConsoleApp.csproj
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@@ -1,14 +1,14 @@
<Project Sdk="Microsoft.NET.Sdk">

<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net10.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net10.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="FileSizeFromBase64.NET" Version="2.0.0" />
</ItemGroup>
<ItemGroup>
<ProjectReference Include="..\..\src\FileSizeFromBase64.NET\FileSizeFromBase64.NET.csproj"/>
</ItemGroup>

</Project>
</Project>
56 changes: 28 additions & 28 deletions tests/FileSizeFromBase64.NET.Tests/FileSizeFromBase64.NET.Tests.csproj
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@@ -1,35 +1,35 @@
<Project Sdk="Microsoft.NET.Sdk">

<PropertyGroup>
<TargetFramework>net10.0</TargetFramework>
<Nullable>enable</Nullable>
<PropertyGroup>
<TargetFramework>net10.0</TargetFramework>
<Nullable>enable</Nullable>

<IsPackable>false</IsPackable>
<NoWarn>$(NoWarn);CA1707</NoWarn>
</PropertyGroup>
<IsPackable>false</IsPackable>
<NoWarn>$(NoWarn);CA1707</NoWarn>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
<PackageReference Include="Shouldly" Version="4.3.0" />
<PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
<PrivateAssets>all</PrivateAssets>
</PackageReference>
<PackageReference Include="coverlet.collector" Version="6.0.4">
<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
<PrivateAssets>all</PrivateAssets>
</PackageReference>
<PackageReference Include="xunit.v3" Version="3.2.2" />
</ItemGroup>
<ItemGroup>
<PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1"/>
<PackageReference Include="Shouldly" Version="4.3.0"/>
<PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
<PrivateAssets>all</PrivateAssets>
</PackageReference>
<PackageReference Include="coverlet.collector" Version="6.0.4">
<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
<PrivateAssets>all</PrivateAssets>
</PackageReference>
<PackageReference Include="xunit.v3" Version="3.2.2"/>
</ItemGroup>

<ItemGroup>
<ProjectReference Include="..\..\src\FileSizeFromBase64.NET\FileSizeFromBase64.NET.csproj" />
</ItemGroup>
<ItemGroup>
<ProjectReference Include="..\..\src\FileSizeFromBase64.NET\FileSizeFromBase64.NET.csproj"/>
</ItemGroup>

<ItemGroup>
<None Update="data.txt">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
</ItemGroup>
<ItemGroup>
<None Update="data.txt">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
</ItemGroup>

</Project>
</Project>