Volian/SourceCode
8
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Browse Source
This commit is contained in:
John Jenko
2009-03-30 15:14:21 +00:00
parent 3420fe1889
commit f784beb005
6 changed files with 955 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

110
PROMS/EPocalipse.IFilter/ComHelper.cs Normal file
View File

@@ -0,0 +1,110 @@
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace EPocalipse.IFilter
{
[ComVisible(false)]
[ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("00000001-0000-0000-C000-000000000046")]
internal interface IClassFactory
{
void CreateInstance([MarshalAs(UnmanagedType.Interface)] object pUnkOuter, ref Guid refiid, [MarshalAs(UnmanagedType.Interface)] out object ppunk);
void LockServer(bool fLock);
}
/// <summary>
/// Utility class to get a Class Factory for a certain Class ID
/// by loading the dll that implements that class
/// </summary>
internal static class ComHelper
{
//DllGetClassObject fuction pointer signature
private delegate int DllGetClassObject(ref Guid ClassId, ref Guid InterfaceId, [Out, MarshalAs(UnmanagedType.Interface)] out object ppunk);
//Some win32 methods to load\unload dlls and get a function pointer
private class Win32NativeMethods
{
[DllImport("kernel32.dll", CharSet=CharSet.Ansi)]
public static extern IntPtr GetProcAddress(IntPtr hModule, string lpProcName);
[DllImport("kernel32.dll")]
public static extern bool FreeLibrary(IntPtr hModule);
[DllImport("kernel32.dll")]
public static extern IntPtr LoadLibrary(string lpFileName);
}
/// <summary>
/// Holds a list of dll handles and unloads the dlls
/// in the destructor
/// </summary>
private class DllList
{
private List<IntPtr> _dllList=new List<IntPtr>();
public void AddDllHandle(IntPtr dllHandle)
{
lock (_dllList)
{
_dllList.Add(dllHandle);
}
}
~DllList()
{
foreach (IntPtr dllHandle in _dllList)
{
try
{
Win32NativeMethods.FreeLibrary(dllHandle);
}
catch { };
}
}
}
static DllList _dllList=new DllList();
/// <summary>
/// Gets a class factory for a specific COM Class ID.
/// </summary>
/// <param name="dllName">The dll where the COM class is implemented</param>
/// <param name="filterPersistClass">The requested Class ID</param>
/// <returns>IClassFactory instance used to create instances of that class</returns>
internal static IClassFactory GetClassFactory(string dllName, string filterPersistClass)
{
//Load the class factory from the dll
IClassFactory classFactory=GetClassFactoryFromDll(dllName, filterPersistClass);
return classFactory;
}
private static IClassFactory GetClassFactoryFromDll(string dllName, string filterPersistClass)
{
//Load the dll
IntPtr dllHandle=Win32NativeMethods.LoadLibrary(dllName);
if (dllHandle==IntPtr.Zero)
return null;
//Keep a reference to the dll until the process\AppDomain dies
_dllList.AddDllHandle(dllHandle);
//Get a pointer to the DllGetClassObject function
IntPtr dllGetClassObjectPtr=Win32NativeMethods.GetProcAddress(dllHandle, "DllGetClassObject");
if (dllGetClassObjectPtr==IntPtr.Zero)
return null;
//Convert the function pointer to a .net delegate
DllGetClassObject dllGetClassObject=(DllGetClassObject)Marshal.GetDelegateForFunctionPointer(dllGetClassObjectPtr, typeof(DllGetClassObject));
//Call the DllGetClassObject to retreive a class factory for out Filter class
Guid filterPersistGUID=new Guid(filterPersistClass);
Guid IClassFactoryGUID=new Guid("00000001-0000-0000-C000-000000000046"); //IClassFactory class id
Object unk;
if (dllGetClassObject(ref filterPersistGUID, ref IClassFactoryGUID, out unk)!=0)
return null;
//Yippie! cast the returned object to IClassFactory
return (unk as IClassFactory);
}
}
}

52
PROMS/EPocalipse.IFilter/EPocalipse.IFilter.csproj Normal file
View File

@@ -0,0 +1,52 @@
<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
<Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
<ProductVersion>8.0.50727</ProductVersion>
<SchemaVersion>2.0</SchemaVersion>
<ProjectGuid>{400462CE-40B3-498F-B95A-B1D2AE679359}</ProjectGuid>
<OutputType>Library</OutputType>
<AppDesignerFolder>Properties</AppDesignerFolder>
<RootNamespace>EPocalipse.IFilter</RootNamespace>
<AssemblyName>EPocalipse.IFilter</AssemblyName>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
<DebugType>full</DebugType>
<Optimize>false</Optimize>
<OutputPath>bin\Debug\</OutputPath>
<DefineConstants>DEBUG;TRACE</DefineConstants>
<ErrorReport>prompt</ErrorReport>
<WarningLevel>4</WarningLevel>
<DocumentationFile>
</DocumentationFile>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
<DebugType>pdbonly</DebugType>
<Optimize>true</Optimize>
<OutputPath>bin\Release\</OutputPath>
<DefineConstants>TRACE</DefineConstants>
<ErrorReport>prompt</ErrorReport>
<WarningLevel>4</WarningLevel>
</PropertyGroup>
<ItemGroup>
<Reference Include="System" />
<Reference Include="System.Data" />
<Reference Include="System.Xml" />
</ItemGroup>
<ItemGroup>
<Compile Include="FilterReader.cs" />
<Compile Include="ComHelper.cs" />
<Compile Include="FilterLoader.cs" />
<Compile Include="IFilter.cs" />
<Compile Include="Properties\AssemblyInfo.cs" />
</ItemGroup>
<Import Project="$(MSBuildBinPath)\Microsoft.CSharp.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>

20
PROMS/EPocalipse.IFilter/EPocalipse.IFilter.sln Normal file
View File

@@ -0,0 +1,20 @@

Microsoft Visual Studio Solution File, Format Version 9.00
# Visual Studio 2005
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "EPocalipse.IFilter", "EPocalipse.IFilter.csproj", "{400462CE-40B3-498F-B95A-B1D2AE679359}"
EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Debug|Any CPU = Debug|Any CPU
Release|Any CPU = Release|Any CPU
EndGlobalSection
GlobalSection(ProjectConfigurationPlatforms) = postSolution
{400462CE-40B3-498F-B95A-B1D2AE679359}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{400462CE-40B3-498F-B95A-B1D2AE679359}.Debug|Any CPU.Build.0 = Debug|Any CPU
{400462CE-40B3-498F-B95A-B1D2AE679359}.Release|Any CPU.ActiveCfg = Release|Any CPU
{400462CE-40B3-498F-B95A-B1D2AE679359}.Release|Any CPU.Build.0 = Release|Any CPU
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE
EndGlobalSection
EndGlobal

226
PROMS/EPocalipse.IFilter/FilterLoader.cs Normal file
View File

@@ -0,0 +1,226 @@
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Win32;
using System.IO;
using System.Runtime.InteropServices.ComTypes;
using System.Runtime.InteropServices;
namespace EPocalipse.IFilter
{
/// <summary>
/// FilterLoader finds the dll and ClassID of the COM object responsible
/// for filtering a specific file extension.
/// It then loads that dll, creates the appropriate COM object and returns
/// a pointer to an IFilter instance
/// </summary>
static class FilterLoader
{
#region CacheEntry
private class CacheEntry
{
public string DllName;
public string ClassName;
public CacheEntry(string dllName, string className)
{
DllName=dllName;
ClassName=className;
}
}
#endregion
static Dictionary<string, CacheEntry> _cache=new Dictionary<string, CacheEntry>();
#region Registry Read String helper
static string ReadStrFromHKLM(string key)
{
return ReadStrFromHKLM(key,null);
}
static string ReadStrFromHKLM(string key, string value)
{
RegistryKey rk=Registry.LocalMachine.OpenSubKey(key);
if (rk==null)
return null;
using (rk)
{
return (string)rk.GetValue(value);
}
}
#endregion
/// <summary>
/// finds an IFilter implementation for a file type
/// </summary>
/// <param name="ext">The extension of the file</param>
/// <returns>an IFilter instance used to retreive text from that file type</returns>
private static IFilter LoadIFilter(string ext)
{
string dllName, filterPersistClass;
//Find the dll and ClassID
if (GetFilterDllAndClass(ext, out dllName, out filterPersistClass))
{
//load the dll and return an IFilter instance.
return LoadFilterFromDll(dllName, filterPersistClass);
}
return null;
}
internal static IFilter LoadAndInitIFilter(string fileName)
{
return LoadAndInitIFilter(fileName,Path.GetExtension(fileName));
}
internal static IFilter LoadAndInitIFilter(string fileName, string extension)
{
IFilter filter=LoadIFilter(extension);
if (filter==null)
return null;
IPersistFile persistFile=(filter as IPersistFile);
if (persistFile!=null)
{
persistFile.Load(fileName, 0);
IFILTER_FLAGS flags;
IFILTER_INIT iflags =
IFILTER_INIT.CANON_HYPHENS |
IFILTER_INIT.CANON_PARAGRAPHS |
IFILTER_INIT.CANON_SPACES |
IFILTER_INIT.APPLY_INDEX_ATTRIBUTES |
IFILTER_INIT.HARD_LINE_BREAKS |
IFILTER_INIT.FILTER_OWNED_VALUE_OK;
if (filter.Init(iflags, 0, IntPtr.Zero, out flags)==IFilterReturnCode.S_OK)
return filter;
}
//If we failed to retreive an IPersistFile interface or to initialize
//the filter, we release it and return null.
Marshal.ReleaseComObject(filter);
return null;
}
private static IFilter LoadFilterFromDll(string dllName, string filterPersistClass)
{
//Get a classFactory for our classID
IClassFactory classFactory=ComHelper.GetClassFactory(dllName, filterPersistClass);
if (classFactory==null)
return null;
//And create an IFilter instance using that class factory
Guid IFilterGUID=new Guid("89BCB740-6119-101A-BCB7-00DD010655AF");
Object obj;
classFactory.CreateInstance(null, ref IFilterGUID, out obj);
return (obj as IFilter);
}
private static bool GetFilterDllAndClass(string ext, out string dllName, out string filterPersistClass)
{
if (!GetFilterDllAndClassFromCache(ext, out dllName, out filterPersistClass))
{
string persistentHandlerClass;
persistentHandlerClass=GetPersistentHandlerClass(ext,true);
if (persistentHandlerClass!=null)
{
GetFilterDllAndClassFromPersistentHandler(persistentHandlerClass,
out dllName, out filterPersistClass);
}
AddExtensionToCache(ext, dllName, filterPersistClass);
}
return (dllName!=null && filterPersistClass!=null);
}
private static void AddExtensionToCache(string ext, string dllName, string filterPersistClass)
{
lock (_cache)
{
_cache.Add(ext.ToLower(), new CacheEntry(dllName, filterPersistClass));
}
}
private static bool GetFilterDllAndClassFromPersistentHandler(string persistentHandlerClass, out string dllName, out string filterPersistClass)
{
dllName=null;
filterPersistClass=null;
//Read the CLASS ID of the IFilter persistent handler
filterPersistClass=ReadStrFromHKLM(@"Software\Classes\CLSID\" + persistentHandlerClass +
@"\PersistentAddinsRegistered\{89BCB740-6119-101A-BCB7-00DD010655AF}");
if (String.IsNullOrEmpty(filterPersistClass))
return false;
//Read the dll name
dllName=ReadStrFromHKLM(@"Software\Classes\CLSID\" + filterPersistClass +
@"\InprocServer32");
return (!String.IsNullOrEmpty(dllName));
}
private static string GetPersistentHandlerClass(string ext, bool searchContentType)
{
//Try getting the info from the file extension
string persistentHandlerClass=GetPersistentHandlerClassFromExtension(ext);
if (String.IsNullOrEmpty(persistentHandlerClass))
//try getting the info from the document type
persistentHandlerClass=GetPersistentHandlerClassFromDocumentType(ext);
if (searchContentType && String.IsNullOrEmpty(persistentHandlerClass))
//Try getting the info from the Content Type
persistentHandlerClass=GetPersistentHandlerClassFromContentType(ext);
return persistentHandlerClass;
}
private static string GetPersistentHandlerClassFromContentType(string ext)
{
string contentType=ReadStrFromHKLM(@"Software\Classes\"+ext,"Content Type");
if (String.IsNullOrEmpty(contentType))
return null;
string contentTypeExtension=ReadStrFromHKLM(@"Software\Classes\MIME\Database\Content Type\"+contentType,
"Extension");
if (ext.Equals(contentTypeExtension, StringComparison.CurrentCultureIgnoreCase))
return null; //No need to look further. This extension does not have any persistent handler
//We know the extension that is assciated with that content type. Simply try again with the new extension
return GetPersistentHandlerClass(contentTypeExtension, false); //Don't search content type this time.
}
private static string GetPersistentHandlerClassFromDocumentType(string ext)
{
//Get the DocumentType of this file extension
string docType=ReadStrFromHKLM(@"Software\Classes\"+ext);
if (String.IsNullOrEmpty(docType))
return null;
//Get the Class ID for this document type
string docClass=ReadStrFromHKLM(@"Software\Classes\" + docType + @"\CLSID");
if (String.IsNullOrEmpty(docType))
return null;
//Now get the PersistentHandler for that Class ID
return ReadStrFromHKLM(@"Software\Classes\CLSID\" + docClass + @"\PersistentHandler");
}
private static string GetPersistentHandlerClassFromExtension(string ext)
{
return ReadStrFromHKLM(@"Software\Classes\"+ext+@"\PersistentHandler");
}
private static bool GetFilterDllAndClassFromCache(string ext, out string dllName, out string filterPersistClass)
{
string lowerExt=ext.ToLower();
lock (_cache)
{
CacheEntry cacheEntry;
if (_cache.TryGetValue(lowerExt, out cacheEntry))
{
dllName=cacheEntry.DllName;
filterPersistClass=cacheEntry.ClassName;
return true;
}
}
dllName=null;
filterPersistClass=null;
return false;
}
}
}

112
PROMS/EPocalipse.IFilter/FilterReader.cs Normal file
View File

@@ -0,0 +1,112 @@
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Runtime.InteropServices;
namespace EPocalipse.IFilter
{
/// <summary>
/// Implements a TextReader that reads from an IFilter.
/// </summary>
public class FilterReader : TextReader
{
IFilter _filter;
private bool _done;
private STAT_CHUNK _currentChunk;
private bool _currentChunkValid;
private char[] _charsLeftFromLastRead;
public override void Close()
{
Dispose(true);
GC.SuppressFinalize(this);
}
~FilterReader()
{
Dispose(false);
}
protected override void Dispose(bool disposing)
{
if (_filter!=null)
Marshal.ReleaseComObject(_filter);
}
public override int Read(char[] array, int offset, int count)
{
int endOfChunksCount=0;
int charsRead=0;
while (!_done && charsRead<count)
{
if (_charsLeftFromLastRead!=null)
{
int charsToCopy=(_charsLeftFromLastRead.Length<count-charsRead)?_charsLeftFromLastRead.Length:count-charsRead;
Array.Copy(_charsLeftFromLastRead,0, array, offset+charsRead, charsToCopy);
charsRead+=charsToCopy;
if (charsToCopy<_charsLeftFromLastRead.Length)
{
char[] tmp=new char[_charsLeftFromLastRead.Length-charsToCopy];
Array.Copy(_charsLeftFromLastRead, charsToCopy, tmp, 0, tmp.Length);
_charsLeftFromLastRead=tmp;
}
else
_charsLeftFromLastRead=null;
continue;
};
if (!_currentChunkValid)
{
IFilterReturnCode res=_filter.GetChunk(out _currentChunk);
_currentChunkValid=(res==IFilterReturnCode.S_OK) && ((_currentChunk.flags & CHUNKSTATE.CHUNK_TEXT)!=0);
if (res==IFilterReturnCode.FILTER_E_END_OF_CHUNKS)
endOfChunksCount++;
if (endOfChunksCount>1)
_done=true; //That's it. no more chuncks available
}
if (_currentChunkValid)
{
uint bufLength=(uint)(count-charsRead);
if (bufLength<8192)
bufLength=8192; //Read ahead
char[] buffer=new char[bufLength];
IFilterReturnCode res=_filter.GetText(ref bufLength, buffer);
buffer[bufLength++] = ' ';
if (res==IFilterReturnCode.S_OK || res==IFilterReturnCode.FILTER_S_LAST_TEXT)
{
int cRead=(int)bufLength;
if (cRead+charsRead>count)
{
int charsLeft=(cRead+charsRead-count);
_charsLeftFromLastRead=new char[charsLeft];
Array.Copy(buffer, cRead-charsLeft, _charsLeftFromLastRead, 0, charsLeft);
cRead-=charsLeft;
}
else
_charsLeftFromLastRead=null;
Array.Copy(buffer, 0, array, offset+charsRead, cRead);
charsRead+=cRead;
}
if (res==IFilterReturnCode.FILTER_S_LAST_TEXT || res==IFilterReturnCode.FILTER_E_NO_MORE_TEXT)
_currentChunkValid=false;
}
}
return charsRead;
}
public FilterReader(string fileName)
{
_filter=FilterLoader.LoadAndInitIFilter(fileName);
if (_filter==null)
throw new ArgumentException("no filter defined for "+fileName);
}
}
}

435
PROMS/EPocalipse.IFilter/IFilter.cs Normal file
View File

@@ -0,0 +1,435 @@
using System;
using System.Text;
using System.Runtime.InteropServices;
//Contains IFilter interface translation
//Most translations are from PInvoke.net
namespace EPocalipse.IFilter
{
[StructLayout(LayoutKind.Sequential)]
public struct FULLPROPSPEC
{
public Guid guidPropSet;
public PROPSPEC psProperty;
}
[StructLayout(LayoutKind.Sequential)]
internal struct FILTERREGION
{
public int idChunk;
public int cwcStart;
public int cwcExtent;
}
[StructLayout(LayoutKind.Explicit)]
public struct PROPSPEC
{
[FieldOffset(0)] public int ulKind; // 0 - string used; 1 - PROPID
[FieldOffset(4)] public int propid;
[FieldOffset(4)] public IntPtr lpwstr;
}
[Flags]
internal enum IFILTER_FLAGS
{
/// <summary>
/// The caller should use the IPropertySetStorage and IPropertyStorage
/// interfaces to locate additional properties.
/// When this flag is set, properties available through COM
/// enumerators should not be returned from IFilter.
/// </summary>
IFILTER_FLAGS_OLE_PROPERTIES = 1
}
/// <summary>
/// Flags controlling the operation of the FileFilter
/// instance.
/// </summary>
[Flags]
internal enum IFILTER_INIT
{
NONE = 0,
/// <summary>
/// Paragraph breaks should be marked with the Unicode PARAGRAPH
/// SEPARATOR (0x2029)
/// </summary>
CANON_PARAGRAPHS = 1,
/// <summary>
/// Soft returns, such as the newline character in Microsoft Word, should
/// be replaced by hard returnsLINE SEPARATOR (0x2028). Existing hard
/// returns can be doubled. A carriage return (0x000D), line feed (0x000A),
/// or the carriage return and line feed in combination should be considered
/// a hard return. The intent is to enable pattern-expression matches that
/// match against observed line breaks.
/// </summary>
HARD_LINE_BREAKS = 2,
/// <summary>
/// Various word-processing programs have forms of hyphens that are not
/// represented in the host character set, such as optional hyphens
/// (appearing only at the end of a line) and nonbreaking hyphens. This flag
/// indicates that optional hyphens are to be converted to nulls, and
/// non-breaking hyphens are to be converted to normal hyphens (0x2010), or
/// HYPHEN-MINUSES (0x002D).
/// </summary>
CANON_HYPHENS = 4,
/// <summary>
/// Just as the CANON_HYPHENS flag standardizes hyphens,
/// this one standardizes spaces. All special space characters, such as
/// nonbreaking spaces, are converted to the standard space character
/// (0x0020).
/// </summary>
CANON_SPACES = 8,
/// <summary>
/// Indicates that the client wants text split into chunks representing
/// public value-type properties.
/// </summary>
APPLY_INDEX_ATTRIBUTES = 16,
/// <summary>
/// Indicates that the client wants text split into chunks representing
/// properties determined during the indexing process.
/// </summary>
APPLY_CRAWL_ATTRIBUTES = 256,
/// <summary>
/// Any properties not covered by the APPLY_INDEX_ATTRIBUTES
/// and APPLY_CRAWL_ATTRIBUTES flags should be emitted.
/// </summary>
APPLY_OTHER_ATTRIBUTES = 32,
/// <summary>
/// Optimizes IFilter for indexing because the client calls the
/// IFilter::Init method only once and does not call IFilter::BindRegion.
/// This eliminates the possibility of accessing a chunk both before and
/// after accessing another chunk.
/// </summary>
INDEXING_ONLY = 64,
/// <summary>
/// The text extraction process must recursively search all linked
/// objects within the document. If a link is unavailable, the
/// IFilter::GetChunk call that would have obtained the first chunk of the
/// link should return FILTER_E_LINK_UNAVAILABLE.
/// </summary>
SEARCH_LINKS = 128,
/// <summary>
/// The content indexing process can return property values set by the filter.
/// </summary>
FILTER_OWNED_VALUE_OK = 512
}
public struct STAT_CHUNK
{
/// <summary>
/// The chunk identifier. Chunk identifiers must be unique for the
/// current instance of the IFilter interface.
/// Chunk identifiers must be in ascending order. The order in which
/// chunks are numbered should correspond to the order in which they appear
/// in the source document. Some search engines can take advantage of the
/// proximity of chunks of various properties. If so, the order in which
/// chunks with different properties are emitted will be important to the
/// search engine.
/// </summary>
public int idChunk;
/// <summary>
/// The type of break that separates the previous chunk from the current
/// chunk. Values are from the CHUNK_BREAKTYPE enumeration.
/// </summary>
[MarshalAs(UnmanagedType.U4)]
public CHUNK_BREAKTYPE breakType;
/// <summary>
/// Flags indicate whether this chunk contains a text-type or a
/// value-type property.
/// Flag values are taken from the CHUNKSTATE enumeration. If the CHUNK_TEXT flag is set,
/// IFilter::GetText should be used to retrieve the contents of the chunk
/// as a series of words.
/// If the CHUNK_VALUE flag is set, IFilter::GetValue should be used to retrieve
/// the value and treat it as a single property value. If the filter dictates that the same
/// content be treated as both text and as a value, the chunk should be emitted twice in two
/// different chunks, each with one flag set.
/// </summary>
[MarshalAs(UnmanagedType.U4)]
public CHUNKSTATE flags;
/// <summary>
/// The language and sublanguage associated with a chunk of text. Chunk locale is used
/// by document indexers to perform proper word breaking of text. If the chunk is
/// neither text-type nor a value-type with data type VT_LPWSTR, VT_LPSTR or VT_BSTR,
/// this field is ignored.
/// </summary>
public int locale;
/// <summary>
/// The property to be applied to the chunk. If a filter requires that the same text
/// have more than one property, it needs to emit the text once for each property
/// in separate chunks.
/// </summary>
public FULLPROPSPEC attribute;
/// <summary>
/// The ID of the source of a chunk. The value of the idChunkSource member depends on the nature of the chunk:
/// If the chunk is a text-type property, the value of the idChunkSource member must be the same as the value of the idChunk member.
/// If the chunk is an public value-type property derived from textual content, the value of the idChunkSource member is the chunk ID for the
/// text-type chunk from which it is derived.
/// If the filter attributes specify to return only public value-type
/// properties, there is no content chunk from which to derive the current
/// public value-type property. In this case, the value of the
/// idChunkSource member must be set to zero, which is an invalid chunk.
/// </summary>
public int idChunkSource;
/// <summary>
/// The offset from which the source text for a derived chunk starts in
/// the source chunk.
/// </summary>
public int cwcStartSource;
/// <summary>
/// The length in characters of the source text from which the current
/// chunk was derived.
/// A zero value signifies character-by-character correspondence between
/// the source text and
/// the derived text. A nonzero value means that no such direct
/// correspondence exists
/// </summary>
public int cwcLenSource;
}
/// <summary>
/// Enumerates the different breaking types that occur between
/// chunks of text read out by the FileFilter.
/// </summary>
public enum CHUNK_BREAKTYPE
{
/// <summary>
/// No break is placed between the current chunk and the previous chunk.
/// The chunks are glued together.
/// </summary>
CHUNK_NO_BREAK = 0,
/// <summary>
/// A word break is placed between this chunk and the previous chunk that
/// had the same attribute.
/// Use of CHUNK_EOW should be minimized because the choice of word
/// breaks is language-dependent,
/// so determining word breaks is best left to the search engine.
/// </summary>
CHUNK_EOW = 1,
/// <summary>
/// A sentence break is placed between this chunk and the previous chunk
/// that had the same attribute.
/// </summary>
CHUNK_EOS = 2,
/// <summary>
/// A paragraph break is placed between this chunk and the previous chunk
/// that had the same attribute.
/// </summary>
CHUNK_EOP = 3,
/// <summary>
/// A chapter break is placed between this chunk and the previous chunk
/// that had the same attribute.
/// </summary>
CHUNK_EOC = 4
}
public enum CHUNKSTATE
{
/// <summary>
/// The current chunk is a text-type property.
/// </summary>
CHUNK_TEXT = 0x1,
/// <summary>
/// The current chunk is a value-type property.
/// </summary>
CHUNK_VALUE = 0x2,
/// <summary>
/// Reserved
/// </summary>
CHUNK_FILTER_OWNED_VALUE = 0x4
}
internal enum IFilterReturnCode : uint
{
/// <summary>
/// Success
/// </summary>
S_OK = 0,
/// <summary>
/// The function was denied access to the filter file.
/// </summary>
E_ACCESSDENIED = 0x80070005,
/// <summary>
/// The function encountered an invalid handle,
/// probably due to a low-memory situation.
/// </summary>
E_HANDLE = 0x80070006,
/// <summary>
/// The function received an invalid parameter.
/// </summary>
E_INVALIDARG = 0x80070057,
/// <summary>
/// Out of memory
/// </summary>
E_OUTOFMEMORY = 0x8007000E,
/// <summary>
/// Not implemented
/// </summary>
E_NOTIMPL = 0x80004001,
/// <summary>
/// Unknown error
/// </summary>
E_FAIL = 0x80000008,
/// <summary>
/// File not filtered due to password protection
/// </summary>
FILTER_E_PASSWORD = 0x8004170B,
/// <summary>
/// The document format is not recognised by the filter
/// </summary>
FILTER_E_UNKNOWNFORMAT = 0x8004170C,
/// <summary>
/// No text in current chunk
/// </summary>
FILTER_E_NO_TEXT = 0x80041705,
/// <summary>
/// No more chunks of text available in object
/// </summary>
FILTER_E_END_OF_CHUNKS = 0x80041700,
/// <summary>
/// No more text available in chunk
/// </summary>
FILTER_E_NO_MORE_TEXT = 0x80041701,
/// <summary>
/// No more property values available in chunk
/// </summary>
FILTER_E_NO_MORE_VALUES = 0x80041702,
/// <summary>
/// Unable to access object
/// </summary>
FILTER_E_ACCESS = 0x80041703,
/// <summary>
/// Moniker doesn't cover entire region
/// </summary>
FILTER_W_MONIKER_CLIPPED = 0x00041704,
/// <summary>
/// Unable to bind IFilter for embedded object
/// </summary>
FILTER_E_EMBEDDING_UNAVAILABLE = 0x80041707,
/// <summary>
/// Unable to bind IFilter for linked object
/// </summary>
FILTER_E_LINK_UNAVAILABLE = 0x80041708,
/// <summary>
/// This is the last text in the current chunk
/// </summary>
FILTER_S_LAST_TEXT = 0x00041709,
/// <summary>
/// This is the last value in the current chunk
/// </summary>
FILTER_S_LAST_VALUES = 0x0004170A
}
[ComImport, Guid("89BCB740-6119-101A-BCB7-00DD010655AF")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
internal interface IFilter
{
/// <summary>
/// The IFilter::Init method initializes a filtering session.
/// </summary>
[PreserveSig]
IFilterReturnCode Init(
//[in] Flag settings from the IFILTER_INIT enumeration for
// controlling text standardization, property output, embedding
// scope, and IFilter access patterns.
IFILTER_INIT grfFlags,
// [in] The size of the attributes array. When nonzero, cAttributes
// takes
// precedence over attributes specified in grfFlags. If no
// attribute flags
// are specified and cAttributes is zero, the default is given by
// the
// PSGUID_STORAGE storage property set, which contains the date and
// time
// of the last write to the file, size, and so on; and by the
// PID_STG_CONTENTS
// 'contents' property, which maps to the main contents of the
// file.
// For more information about properties and property sets, see
// Property Sets.
int cAttributes,
//[in] Array of pointers to FULLPROPSPEC structures for the
// requested properties.
// When cAttributes is nonzero, only the properties in aAttributes
// are returned.
IntPtr aAttributes,
// [out] Information about additional properties available to the
// caller; from the IFILTER_FLAGS enumeration.
out IFILTER_FLAGS pdwFlags);
/// <summary>
/// The IFilter::GetChunk method positions the filter at the beginning
/// of the next chunk,
/// or at the first chunk if this is the first call to the GetChunk
/// method, and returns a description of the current chunk.
/// </summary>
[PreserveSig]
IFilterReturnCode GetChunk(out STAT_CHUNK pStat);
/// <summary>
/// The IFilter::GetText method retrieves text (text-type properties)
/// from the current chunk,
/// which must have a CHUNKSTATE enumeration value of CHUNK_TEXT.
/// </summary>
[PreserveSig]
IFilterReturnCode GetText(
// [in/out] On entry, the size of awcBuffer array in wide/Unicode
// characters. On exit, the number of Unicode characters written to
// awcBuffer.
// Note that this value is not the number of bytes in the buffer.
ref uint pcwcBuffer,
// Text retrieved from the current chunk. Do not terminate the
// buffer with a character.
[Out(), MarshalAs(UnmanagedType.LPArray)]
char[] awcBuffer);
/// <summary>
/// The IFilter::GetValue method retrieves a value (public
/// value-type property) from a chunk,
/// which must have a CHUNKSTATE enumeration value of CHUNK_VALUE.
/// </summary>
[PreserveSig]
int GetValue(
// Allocate the PROPVARIANT structure with CoTaskMemAlloc. Some
// PROPVARIANT
// structures contain pointers, which can be freed by calling the
// PropVariantClear function.
// It is up to the caller of the GetValue method to call the
// PropVariantClear method.
// ref IntPtr ppPropValue
// [MarshalAs(UnmanagedType.Struct)]
ref IntPtr PropVal);
/// <summary>
/// The IFilter::BindRegion method retrieves an interface representing
/// the specified portion of the object.
/// Currently reserved for future use.
/// </summary>
[PreserveSig]
int BindRegion(ref FILTERREGION origPos,
ref Guid riid, ref object ppunk);
}
}