how i can send gzip instade deflate by skip header - c++

Question

i write a c++ http server ( Microsoft http server api )
that send html page file in gzip format
and gzip file is static
for example file page1.htm and page1.htm.gz are in same directory
according to
http://en.wikipedia.org/wiki/Gzip
i know that gzip is deflate with extra header
and deflate is part of gzip
how i can sending gzip instade deflate by skip header
fileHandle=CreateFile( "page1.htm.gz" ,dwAccess,dwShare,NULL,dwCreationFlags,dwAttributes,NULL);
....
ADD_KNOWN_HEADER(response, HttpHeaderContentEncoding, "deflate" );
HTTP_DATA_CHUNK dataChunk;
{
HTTP_DATA_CHUNK dataChunk;
response.EntityChunkCount = 1;
dataChunk.DataChunkType = HttpDataChunkFromFileHandle;
dataChunk.FromFileHandle.FileHandle =fileHandle;
dataChunk.FromFileHandle.ByteRange.StartingOffset.QuadPart =9;// 9 is gzip header len
dataChunk.FromFileHandle.ByteRange.Length.QuadPart = HTTP_BYTE_RANGE_TO_EOF;
response.pEntityChunks=&dataChunk;
}
.....

Answer 1

The deflate and gzip encoding are not quite the same thing, although the differences are minor.
When you are sending gzip, change your code to:
ADD_KNOWN_HEADER(response, HttpHeaderContentEncoding, "gzip" );
You should do that of course if gzip is listed in Accept-Encoding.
Here's an excerpt from the gzip FAQ:
“ What's the difference between the "gzip" and "deflate" HTTP 1.1
encodings?
"gzip" is the gzip format, and "deflate" is the zlib format. They
should probably have called the second one "zlib" instead to avoid
confusion with the raw deflate compressed data format. While the HTTP
1.1 RFC 2616 correctly points to the zlib specification in RFC 1950 for the "deflate" transfer encoding, there have been reports of
servers and browsers that incorrectly produce or expect raw deflate
data per the deflate specficiation in RFC 1951, most notably
Microsoft. So even though the "deflate" transfer encoding using the
zlib format would be the more efficient approach (and in fact exactly
what the zlib format was designed for), using the "gzip" transfer
encoding is probably more reliable due to an unfortunate choice of
name on the part of the HTTP 1.1 authors.”
http://www.gzip.org/zlib/zlib_faq.html#faq38