RPA Robotic Process Automation – Make Large PDF Document Searchable Using Parallel Processing – VB.NET

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RPA Robotic Process Automation – Make Large PDF Document Searchable Using Parallel Processing – VB.NET

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ByteScout-Robotic-Process-Automation-VB-NET-VB-NET.pdf

How to make large PDF document searchable using parallel processing in VB.NET with ByteScout Robotic Process Automation

What is ByteScout Robotic Process Automation? It is components and tools for quick RPA (Robotic Process Automation) implementation.

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Module1.vb

      Imports System.IO
Imports System.Threading
Imports Bytescout.PDFExtractor

Module Module1

    ' Limit to 4 threads in queue.
    ' Set this value to number of your processor cores for max performance.
    Dim ThreadLimiter as Semaphore = New Semaphore(4, 4)

	<MTAThread>
	Sub Main()

		Const inputFile = "sample.pdf"
		Const resultFile = "result.pdf"

		Dim pageCount As Integer

		' Get document page count
		Using infoExtractor = New InfoExtractor()
			infoExtractor.LoadDocumentFromFile(inputFile)
			pageCount = infoExtractor.GetPageCount()
		End Using

		' Process the document by 10-page pieces
		Dim numberOfThreads As Integer
		numberOfThreads = pageCount \ 10
		If (pageCount - numberOfThreads * 10 > 0) Then numberOfThreads = numberOfThreads + 1

		Dim doneEvents(numberOfThreads - 1) As WaitHandle
		Dim stopwatch As Stopwatch = Stopwatch.StartNew()
		Dim startPage, endPage As Integer
		Dim pieces(numberOfThreads - 1) As String

		' Run threads
		For i As Integer = 0 To numberOfThreads - 1

            ' Wait for the queue
		    ThreadLimiter.WaitOne()

			doneEvents(i) = New ManualResetEvent(False)
			startPage = i * 10
			endPage = Math.Min(pageCount - 1, (i + 1) * 10 - 1)
			
			If numberOfThreads = 1 Then
				endPage = endPage - 1
			End If
						
			pieces(i) = String.Format("temp-{0}-{1}.pdf", startPage, endPage)
			ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ThreadProc), New Object() {i, doneEvents(i), inputFile, pieces(i), startPage, endPage})

		Next

		' Wait for all threads
		WaitHandle.WaitAll(doneEvents)

		' Merge pieces 
		Using merger = New DocumentMerger
			merger.Merge(pieces, resultFile)
		End Using

		' Delete temp files
		For Each tempFile As String In pieces
			File.Delete(tempFile)
		Next
		
		Console.WriteLine("All done in {0}.", stopwatch.Elapsed)
		Console.WriteLine()

		Console.WriteLine("Press any key to exit...")
		Console.ReadKey()

	End Sub

	Sub ThreadProc(ByVal stateInfo As Object)

		Dim threadIndex As Integer = stateInfo(0)
		Dim waitEvent As ManualResetEvent = stateInfo(1)
		Dim inputFile As String = stateInfo(2)
		Dim outputFile As String = stateInfo(3)
		Dim startPage As Integer = stateInfo(4)
		Dim endPage As Integer = stateInfo(5)

	    Try

	        Console.WriteLine("Thread #{0} started with the page range from {1} to {2}.", threadIndex, startPage, endPage)

		    Dim stopwatch As Stopwatch = Stopwatch.StartNew()

		    ' Extract a piece of document
		    Dim chunk As String = String.Format("temp-{0}-{1}", startPage, endPage)
		    Using splitter = New DocumentSplitter
			    splitter.ExtractPageRange(inputFile, chunk, startPage + 1, endPage + 1)
		    End Using

		    ' Process the piece
		    Using searchablePdfMaker As New SearchablePDFMaker("demo", "demo")

			    searchablePdfMaker.OCRDetectPageRotation = True
			    searchablePdfMaker.OCRLanguageDataFolder = "c:\Program Files\Bytescout PDF Extractor SDK\ocrdata_best\"
			    searchablePdfMaker.LoadDocumentFromFile(chunk)

			    ' 300 DPI resolution is recommended. 
			    ' Using of higher values will slow down the processing but does not guarantee the higher quality.
			    searchablePdfMaker.OCRResolution = 300

			    searchablePdfMaker.MakePDFSearchable(outputFile)

		    End Using

		    File.Delete(chunk)

		    Console.WriteLine("Thread #{0} finished in {1}.", threadIndex, stopwatch.Elapsed)

	    Finally

            ' Signal the thread is finished
	        waitEvent.Set()

            ' Release semaphore
	        ThreadLimiter.Release()

	    End Try

		
	End Sub

End Module

MultithreadProcessing.sln

      
Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 15
VisualStudioVersion = 15.0.26730.8
MinimumVisualStudioVersion = 10.0.40219.1
Project("{F184B08F-C81C-45F6-A57F-5ABD9991F28F}") = "MultithreadProcessing", "MultithreadProcessing.vbproj", "{F18881BC-38FA-4D69-AD4E-4DC6CB637251}"
EndProject
Global
	GlobalSection(SolutionConfigurationPlatforms) = preSolution
		Debug|Any CPU = Debug|Any CPU
		Release|Any CPU = Release|Any CPU
	EndGlobalSection
	GlobalSection(ProjectConfigurationPlatforms) = postSolution
		{F18881BC-38FA-4D69-AD4E-4DC6CB637251}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
		{F18881BC-38FA-4D69-AD4E-4DC6CB637251}.Debug|Any CPU.Build.0 = Debug|Any CPU
		{F18881BC-38FA-4D69-AD4E-4DC6CB637251}.Release|Any CPU.ActiveCfg = Release|Any CPU
		{F18881BC-38FA-4D69-AD4E-4DC6CB637251}.Release|Any CPU.Build.0 = Release|Any CPU
	EndGlobalSection
	GlobalSection(SolutionProperties) = preSolution
		HideSolutionNode = FALSE
	EndGlobalSection
	GlobalSection(ExtensibilityGlobals) = postSolution
		SolutionGuid = {BADFE9BE-5CD2-45AC-9023-A1BB794B42E4}
	EndGlobalSection
EndGlobal

MultithreadProcessing.vbproj

      <?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <ProjectGuid>{F18881BC-38FA-4D69-AD4E-4DC6CB637251}</ProjectGuid>
    <OutputType>Exe</OutputType>
    <StartupObject>MultithreadProcessing.Module1</StartupObject>
    <RootNamespace>MultithreadProcessing</RootNamespace>
    <AssemblyName>MultithreadProcessing</AssemblyName>
    <FileAlignment>512</FileAlignment>
    <MyType>Console</MyType>
    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <DefineDebug>true</DefineDebug>
    <DefineTrace>true</DefineTrace>
    <OutputPath>bin\Debug\</OutputPath>
    <DocumentationFile>MultithreadProcessing.xml</DocumentationFile>
    <NoWarn>42016,41999,42017,42018,42019,42032,42036,42020,42021,42022</NoWarn>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DebugType>pdbonly</DebugType>
    <DefineDebug>false</DefineDebug>
    <DefineTrace>true</DefineTrace>
    <Optimize>true</Optimize>
    <OutputPath>bin\Release\</OutputPath>
    <DocumentationFile>MultithreadProcessing.xml</DocumentationFile>
    <NoWarn>42016,41999,42017,42018,42019,42032,42036,42020,42021,42022</NoWarn>
  </PropertyGroup>
  <PropertyGroup>
    <OptionExplicit>On</OptionExplicit>
  </PropertyGroup>
  <PropertyGroup>
    <OptionCompare>Binary</OptionCompare>
  </PropertyGroup>
  <PropertyGroup>
    <OptionStrict>Off</OptionStrict>
  </PropertyGroup>
  <PropertyGroup>
    <OptionInfer>On</OptionInfer>
  </PropertyGroup>
  <PropertyGroup>
    <ApplicationManifest>My Project\app.manifest</ApplicationManifest>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="Bytescout.PDFExtractor, Version=8.2.0.2710, Culture=neutral, PublicKeyToken=f7dd1bd9d40a50eb, processorArchitecture=MSIL">
      <SpecificVersion>False</SpecificVersion>
      <HintPath>S:\Bytescout\PDF Extractor SDK\Bytescout.PDFExtractor\bin\Debug_FULL_4.0\Bytescout.PDFExtractor.dll</HintPath>
    </Reference>
    <Reference Include="Bytescout.PDFExtractor.OCRExtension, Version=8.2.0.2710, Culture=neutral, PublicKeyToken=f7dd1bd9d40a50eb, processorArchitecture=MSIL">
      <SpecificVersion>False</SpecificVersion>
      <HintPath>S:\Bytescout\PDF Extractor SDK\Bytescout.PDFExtractor\bin\Debug_FULL_4.0\Bytescout.PDFExtractor.OCRExtension.dll</HintPath>
    </Reference>
    <Reference Include="System" />
    <Reference Include="System.Data" />
    <Reference Include="System.Deployment" />
    <Reference Include="System.Xml" />
    <Reference Include="System.Core" />
    <Reference Include="System.Xml.Linq" />
    <Reference Include="System.Data.DataSetExtensions" />
  </ItemGroup>
  <ItemGroup>
    <Import Include="Microsoft.VisualBasic" />
    <Import Include="System" />
    <Import Include="System.Collections" />
    <Import Include="System.Collections.Generic" />
    <Import Include="System.Data" />
    <Import Include="System.Diagnostics" />
    <Import Include="System.Linq" />
    <Import Include="System.Xml.Linq" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="Module1.vb" />
    <Compile Include="My Project\AssemblyInfo.vb" />
    <Compile Include="My Project\Application.Designer.vb">
      <AutoGen>True</AutoGen>
      <DependentUpon>Application.myapp</DependentUpon>
    </Compile>
    <Compile Include="My Project\Resources.Designer.vb">
      <AutoGen>True</AutoGen>
      <DesignTime>True</DesignTime>
      <DependentUpon>Resources.resx</DependentUpon>
    </Compile>
    <Compile Include="My Project\Settings.Designer.vb">
      <AutoGen>True</AutoGen>
      <DependentUpon>Settings.settings</DependentUpon>
      <DesignTimeSharedInput>True</DesignTimeSharedInput>
    </Compile>
  </ItemGroup>
  <ItemGroup>
    <EmbeddedResource Include="My Project\Resources.resx">
      <Generator>VbMyResourcesResXFileCodeGenerator</Generator>
      <LastGenOutput>Resources.Designer.vb</LastGenOutput>
      <CustomToolNamespace>My.Resources</CustomToolNamespace>
      <SubType>Designer</SubType>
    </EmbeddedResource>
  </ItemGroup>
  <ItemGroup>
    <None Include="My Project\app.manifest" />
    <None Include="My Project\Application.myapp">
      <Generator>MyApplicationCodeGenerator</Generator>
      <LastGenOutput>Application.Designer.vb</LastGenOutput>
    </None>
    <None Include="My Project\Settings.settings">
      <Generator>SettingsSingleFileGenerator</Generator>
      <CustomToolNamespace>My</CustomToolNamespace>
      <LastGenOutput>Settings.Designer.vb</LastGenOutput>
    </None>
    <Content Include="sample.pdf">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </Content>
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.VisualBasic.targets" />
  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
       Other similar extension points exist, see Microsoft.Common.targets.
  <Target Name="BeforeBuild">
  </Target>
  <Target Name="AfterBuild">
  </Target>
  -->
</Project>