[System.Security.SecurityCritical] // auto-generated
private unsafe bool FindCodePage(int codePage)
{
Debug.Assert(m_codePageHeader != null && m_codePageHeader.Length == CODEPAGE_HEADER_SIZE, "m_codePageHeader expected to match in size the struct CodePageHeader");
// Loop through all of the m_pCodePageIndex[] items to find our code page
byte[] codePageIndex = new byte[sizeof(CodePageIndex)];
lock (s_streamLock)
{
// seek to the first CodePageIndex entry
s_codePagesEncodingDataStream.Seek(CODEPAGE_DATA_FILE_HEADER_SIZE, SeekOrigin.Begin);
int codePagesCount;
fixed(byte *pBytes = &s_codePagesDataHeader[0])
{
CodePageDataFileHeader *pDataHeader = (CodePageDataFileHeader *)pBytes;
codePagesCount = pDataHeader->CodePageCount;
}
fixed(byte *pBytes = &codePageIndex[0])
{
CodePageIndex *pCodePageIndex = (CodePageIndex *)pBytes;
for (int i = 0; i < codePagesCount; i++)
{
s_codePagesEncodingDataStream.Read(codePageIndex, 0, codePageIndex.Length);
if (pCodePageIndex->CodePage == codePage)
{
// Found it!
long position = s_codePagesEncodingDataStream.Position;
s_codePagesEncodingDataStream.Seek((long)pCodePageIndex->Offset, SeekOrigin.Begin);
s_codePagesEncodingDataStream.Read(m_codePageHeader, 0, m_codePageHeader.Length);
m_firstDataWordOffset = (int)s_codePagesEncodingDataStream.Position; // stream now pointing to the codepage data
if (i == codePagesCount - 1) // last codepage
{
m_dataSize = (int)(s_codePagesEncodingDataStream.Length - pCodePageIndex->Offset - m_codePageHeader.Length);
}
else
{
// Read Next codepage data to get the offset and then calculate the size
s_codePagesEncodingDataStream.Seek(position, SeekOrigin.Begin);
int currentOffset = pCodePageIndex->Offset;
s_codePagesEncodingDataStream.Read(codePageIndex, 0, codePageIndex.Length);
m_dataSize = pCodePageIndex->Offset - currentOffset - m_codePageHeader.Length;
}
return(true);
}
}
}
}
// Couldn't find it
return(false);
}
private static unsafe CodePageHeader *FindCodePage(int codePage)
{
for (int i = 0; i < m_pCodePageFileHeader.CodePageCount; i++)
{
CodePageIndex *indexPtr = &m_pCodePageFileHeader.CodePages + i;
if (indexPtr->CodePage == codePage)
{
return((CodePageHeader *)(m_pCodePageFileHeader + indexPtr->Offset));
}
}
return(null);
}
[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);
}
internal static unsafe void ReadCodePageIndex(Stream stream, Span <byte> codePageIndex)
{
stream.Read(codePageIndex);
if (!BitConverter.IsLittleEndian)
{
fixed(byte *pBytes = &codePageIndex[0])
{
CodePageIndex *p = (CodePageIndex *)pBytes;
char * pCodePageName = &p->CodePageName;
for (int i = 0; i < 16; i++)
{
pCodePageName[i] = (char)BinaryPrimitives.ReverseEndianness((ushort)pCodePageName[i]);
}
p->CodePage = BinaryPrimitives.ReverseEndianness(p->CodePage);
p->ByteCount = BinaryPrimitives.ReverseEndianness(p->ByteCount);
p->Offset = BinaryPrimitives.ReverseEndianness(p->Offset);
}
}
}
[System.Security.SecurityCritical] // auto-generated
internal static unsafe int GetCodePageByteSize(int codePage)
{
// Loop through all of the m_pCodePageIndex[] items to find our code page
byte[] codePageIndex = new byte[sizeof(CodePageIndex)];
lock (s_streamLock)
{
// seek to the first CodePageIndex entry
s_codePagesEncodingDataStream.Seek(CODEPAGE_DATA_FILE_HEADER_SIZE, SeekOrigin.Begin);
int codePagesCount;
fixed(byte *pBytes = &s_codePagesDataHeader[0])
{
CodePageDataFileHeader *pDataHeader = (CodePageDataFileHeader *)pBytes;
codePagesCount = pDataHeader->CodePageCount;
}
fixed(byte *pBytes = &codePageIndex[0])
{
CodePageIndex *pCodePageIndex = (CodePageIndex *)pBytes;
for (int i = 0; i < codePagesCount; i++)
{
s_codePagesEncodingDataStream.Read(codePageIndex, 0, codePageIndex.Length);
if (pCodePageIndex->CodePage == codePage)
{
Debug.Assert(pCodePageIndex->ByteCount == 1 || pCodePageIndex->ByteCount == 2,
"[BaseCodePageEncoding] Code page (" + codePage + ") has invalid byte size (" + pCodePageIndex->ByteCount + ") in table");
// Return what it says for byte count
return(pCodePageIndex->ByteCount);
}
}
}
}
// Couldn't find it
return(0);
}
private static unsafe void ReadCodePageIndex(Stream stream, Span <byte> codePageIndex)
{
Debug.Assert(stream is UnmanagedMemoryStream, "UnmanagedMemoryStream will read a full buffer on one call to Read.");
int bytesRead = stream.Read(codePageIndex);
Debug.Assert(bytesRead == codePageIndex.Length);
if (!BitConverter.IsLittleEndian)
{
fixed(byte *pBytes = &codePageIndex[0])
{
CodePageIndex *p = (CodePageIndex *)pBytes;
char * pCodePageName = &p->CodePageName;
for (int i = 0; i < 16; i++)
{
pCodePageName[i] = (char)BinaryPrimitives.ReverseEndianness((ushort)pCodePageName[i]);
}
p->CodePage = BinaryPrimitives.ReverseEndianness(p->CodePage);
p->ByteCount = BinaryPrimitives.ReverseEndianness(p->ByteCount);
p->Offset = BinaryPrimitives.ReverseEndianness(p->Offset);
}
}
}
