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// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
#if FEATURE_CODEPAGES_FILE
namespace System.Text
{
using System;
using System.Diagnostics.Contracts;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Security;
using System.Collections;
using System.Runtime.CompilerServices;
using System.Runtime.Serialization;
using System.Runtime.Versioning;
using System.Security.Permissions;
using Microsoft.Win32.SafeHandles;
// Our input file data structures look like:
//
// Header Structure Looks Like:
// struct NLSPlusHeader
// {
// WORD[16] filename; // 32 bytes
// WORD[4] version; // 8 bytes = 40 // I.e: 3, 2, 0, 0
// WORD count; // 2 bytes = 42 // Number of code page index's that'll follow
// }
//
// Each code page section looks like:
// struct NLSCodePageIndex
// {
// WORD[16] codePageName; // 32 bytes
// WORD codePage; // +2 bytes = 34
// WORD byteCount; // +2 bytes = 36
// DWORD offset; // +4 bytes = 40 // Bytes from beginning of FILE.
// }
//
// Each code page then has its own header
// struct NLSCodePage
// {
// WORD[16] codePageName; // 32 bytes
// WORD[4] version; // 8 bytes = 40 // I.e: 3.2.0.0
// WORD codePage; // 2 bytes = 42
// WORD byteCount; // 2 bytes = 44 // 1 or 2 byte code page (SBCS or DBCS)
// WORD unicodeReplace; // 2 bytes = 46 // default replacement unicode character
// WORD byteReplace; // 2 bytes = 48 // default replacement byte(s)
// BYTE[] data; // data section
// }
[Serializable]
internal abstract class BaseCodePageEncoding : EncodingNLS, ISerializable
{
// Static & Const stuff
internal const String CODE_PAGE_DATA_FILE_NAME = "codepages.nlp";
[NonSerialized]
protected int dataTableCodePage;
// Variables to help us allocate/mark our memory section correctly
[NonSerialized]
protected bool bFlagDataTable = true;
[NonSerialized]
protected int iExtraBytes = 0;
// Our private unicode to bytes best fit array and visa versa.
[NonSerialized]
protected char[] arrayUnicodeBestFit = null;
[NonSerialized]
protected char[] arrayBytesBestFit = null;
// This is used to help ISCII, EUCJP and ISO2022 figure out they're MlangEncodings
[NonSerialized]
protected bool m_bUseMlangTypeForSerialization = false;
[System.Security.SecuritySafeCritical] // static constructors should be safe to call
static BaseCodePageEncoding()
{
}
//
// This is the header for the native data table that we load from CODE_PAGE_DATA_FILE_NAME.
//
// Explicit layout is used here since a syntax like char[16] can not be used in sequential layout.
[StructLayout(LayoutKind.Explicit)]
internal unsafe struct CodePageDataFileHeader
{
[FieldOffset(0)]
internal char TableName; // WORD[16]
[FieldOffset(0x20)]
internal ushort Version; // WORD[4]
[FieldOffset(0x28)]
internal short CodePageCount; // WORD
[FieldOffset(0x2A)]
internal short unused1; // Add a unused WORD so that CodePages is aligned with DWORD boundary.
// Otherwise, 64-bit version will fail.
[FieldOffset(0x2C)]
internal CodePageIndex CodePages; // Start of code page index
}
[StructLayout(LayoutKind.Explicit, Pack=2)]
internal unsafe struct CodePageIndex
{
[FieldOffset(0)]
internal char CodePageName; // WORD[16]
[FieldOffset(0x20)]
internal short CodePage; // WORD
[FieldOffset(0x22)]
internal short ByteCount; // WORD
[FieldOffset(0x24)]
internal int Offset; // DWORD
}
[StructLayout(LayoutKind.Explicit)]
internal unsafe struct CodePageHeader
{
[FieldOffset(0)]
internal char CodePageName; // WORD[16]
[FieldOffset(0x20)]
internal ushort VersionMajor; // WORD
[FieldOffset(0x22)]
internal ushort VersionMinor; // WORD
[FieldOffset(0x24)]
internal ushort VersionRevision;// WORD
[FieldOffset(0x26)]
internal ushort VersionBuild; // WORD
[FieldOffset(0x28)]
internal short CodePage; // WORD
[FieldOffset(0x2a)]
internal short ByteCount; // WORD // 1 or 2 byte code page (SBCS or DBCS)
[FieldOffset(0x2c)]
internal char UnicodeReplace; // WORD // default replacement unicode character
[FieldOffset(0x2e)]
internal ushort ByteReplace; // WORD // default replacement bytes
[FieldOffset(0x30)]
internal short FirstDataWord; // WORD[]
}
// Initialize our global stuff
[SecurityCritical]
unsafe static CodePageDataFileHeader* m_pCodePageFileHeader =
(CodePageDataFileHeader*)GlobalizationAssembly.GetGlobalizationResourceBytePtr(
typeof(CharUnicodeInfo).Assembly, CODE_PAGE_DATA_FILE_NAME);
// Real variables
[NonSerialized]
[SecurityCritical]
unsafe protected CodePageHeader* pCodePage = null;
// Safe handle wrapper around section map view
[System.Security.SecurityCritical] // auto-generated
[NonSerialized]
protected SafeViewOfFileHandle safeMemorySectionHandle = null;
// Safe handle wrapper around mapped file handle
[System.Security.SecurityCritical] // auto-generated
[NonSerialized]
protected SafeFileMappingHandle safeFileMappingHandle = null;
[System.Security.SecurityCritical] // auto-generated
internal BaseCodePageEncoding(int codepage) : this(codepage, codepage)
{
}
[System.Security.SecurityCritical] // auto-generated
internal BaseCodePageEncoding(int codepage, int dataCodePage) :
base(codepage == 0? Microsoft.Win32.Win32Native.GetACP(): codepage)
{
// Remember number of code page that we'll be using the table for.
dataTableCodePage = dataCodePage;
LoadCodePageTables();
}
// Constructor called by serialization.
[System.Security.SecurityCritical] // auto-generated
internal BaseCodePageEncoding(SerializationInfo info, StreamingContext context) : base(0)
{
// We cannot ever call this, we've proxied ourselved to CodePageEncoding
throw new ArgumentNullException("this");
}
// ISerializable implementation
#if FEATURE_SERIALIZATION
[System.Security.SecurityCritical] // auto-generated_required
void ISerializable.GetObjectData(SerializationInfo info, StreamingContext context)
{
// Make sure to get teh base stuff too This throws if info is null
SerializeEncoding(info, context);
Contract.Assert(info!=null, "[BaseCodePageEncoding.GetObjectData] Expected null info to throw");
// Just need Everett maxCharSize (BaseCodePageEncoding) or m_maxByteSize (MLangBaseCodePageEncoding)
info.AddValue(m_bUseMlangTypeForSerialization ? "m_maxByteSize" : "maxCharSize",
this.IsSingleByte ? 1 : 2);
// Use this class or MLangBaseCodePageEncoding as our deserializer.
info.SetType(m_bUseMlangTypeForSerialization ? typeof(MLangCodePageEncoding) :
typeof(CodePageEncoding));
}
#endif
// We need to load tables for our code page
[System.Security.SecurityCritical] // auto-generated
private unsafe void LoadCodePageTables()
{
CodePageHeader* pCodePage = FindCodePage(dataTableCodePage);
// Make sure we have one
if (pCodePage == null)
{
// Didn't have one
throw new NotSupportedException(
Environment.GetResourceString("NotSupported_NoCodepageData", CodePage));
}
// Remember our code page
this.pCodePage = pCodePage;
// We had it, so load it
LoadManagedCodePage();
}
// Look up the code page pointer
[System.Security.SecurityCritical] // auto-generated
private static unsafe CodePageHeader* FindCodePage(int codePage)
{
// We'll have to loop through all of the m_pCodePageIndex[] items to find our code page, this isn't
// binary or anything so its not monsterously fast.
for (int i = 0; i < m_pCodePageFileHeader->CodePageCount; i++)
{
CodePageIndex* pCodePageIndex = (&(m_pCodePageFileHeader->CodePages)) + i;
if (pCodePageIndex->CodePage == codePage)
{
// Found it!
CodePageHeader* pCodePage =
(CodePageHeader*)((byte*)m_pCodePageFileHeader + pCodePageIndex->Offset);
return pCodePage;
}
}
// Couldn't find it
return null;
}
// Get our code page byte count
[System.Security.SecurityCritical] // auto-generated
internal static unsafe int GetCodePageByteSize(int codePage)
{
// Get our code page info
CodePageHeader* pCodePage = FindCodePage(codePage);
// If null return 0
if (pCodePage == null)
return 0;
Contract.Assert(pCodePage->ByteCount == 1 || pCodePage->ByteCount == 2,
"[BaseCodePageEncoding] Code page (" + codePage + ") has invalid byte size (" + pCodePage->ByteCount + ") in table");
// Return what it says for byte count
return pCodePage->ByteCount;
}
// We have a managed code page entry, so load our tables
[System.Security.SecurityCritical]
protected abstract unsafe void LoadManagedCodePage();
// Allocate memory to load our code page
[System.Security.SecurityCritical] // auto-generated
[ResourceExposure(ResourceScope.None)]
[ResourceConsumption(ResourceScope.Machine, ResourceScope.Machine)]
protected unsafe byte* GetSharedMemory(int iSize)
{
// Build our name
String strName = GetMemorySectionName();
IntPtr mappedFileHandle;
// This gets shared memory for our map. If its can't, it gives us clean memory.
Byte *pMemorySection = EncodingTable.nativeCreateOpenFileMapping(strName, iSize, out mappedFileHandle);
Contract.Assert(pMemorySection != null,
"[BaseCodePageEncoding.GetSharedMemory] Expected non-null memory section to be opened");
// If that failed, we have to die.
if (pMemorySection == null)
throw new OutOfMemoryException(
Environment.GetResourceString("Arg_OutOfMemoryException"));
// if we have null file handle. this means memory was allocated after
// failing to open the mapped file.
if (mappedFileHandle != IntPtr.Zero)
{
safeMemorySectionHandle = new SafeViewOfFileHandle((IntPtr) pMemorySection, true);
safeFileMappingHandle = new SafeFileMappingHandle(mappedFileHandle, true);
}
return pMemorySection;
}
[System.Security.SecurityCritical] // auto-generated
protected unsafe virtual String GetMemorySectionName()
{
int iUseCodePage = this.bFlagDataTable ? dataTableCodePage : CodePage;
String strName = String.Format(CultureInfo.InvariantCulture, "NLS_CodePage_{0}_{1}_{2}_{3}_{4}",
iUseCodePage, this.pCodePage->VersionMajor, this.pCodePage->VersionMinor,
this.pCodePage->VersionRevision, this.pCodePage->VersionBuild);
return strName;
}
[System.Security.SecurityCritical]
protected abstract unsafe void ReadBestFitTable();
[System.Security.SecuritySafeCritical] //
internal override char[] GetBestFitUnicodeToBytesData()
{
// Read in our best fit table if necessary
if (arrayUnicodeBestFit == null) ReadBestFitTable();
Contract.Assert(arrayUnicodeBestFit != null,
"[BaseCodePageEncoding.GetBestFitUnicodeToBytesData]Expected non-null arrayUnicodeBestFit");
// Normally we don't have any best fit data.
return arrayUnicodeBestFit;
}
[System.Security.SecuritySafeCritical] //
internal override char[] GetBestFitBytesToUnicodeData()
{
// Read in our best fit table if necessary
if (arrayBytesBestFit == null) ReadBestFitTable();
Contract.Assert(arrayBytesBestFit != null,
"[BaseCodePageEncoding.GetBestFitBytesToUnicodeData]Expected non-null arrayBytesBestFit");
// Normally we don't have any best fit data.
return arrayBytesBestFit;
}
// During the AppDomain shutdown the Encoding class may already finalized and the memory section
// is invalid. so we detect that by validating the memory section handle then re-initialize the memory
// section by calling LoadManagedCodePage() method and eventually the mapped file handle and
// the memory section pointer will get finalized one more time.
[System.Security.SecurityCritical] // auto-generated
internal unsafe void CheckMemorySection()
{
if (safeMemorySectionHandle != null && safeMemorySectionHandle.DangerousGetHandle() == IntPtr.Zero)
{
LoadManagedCodePage();
}
}
}
}
#endif // FEATURE_CODEPAGES_FILE
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