The level of compression. Can be given as 0 for no compression up to 9
for maximum compression. If not given, the default compression level will
be the default compression level of the zlib library.
encoding_mode
The encoding mode. Can be FORCE_GZIP (the default)
or FORCE_DEFLATE.
If you use FORCE_DEFLATE, you get a standard zlib
deflated string (inclusive zlib headers) after the gzip file header but
without the trailing crc32 checksum.
Return Values
The encoded string, or FALSE if an error occurred.
Examples
The resulting data contains the appropriate headers and data
structure to make a standard .gz file, e.g.:
