How much memory should be allocated for the internal compression state.
A value of 1 uses minimum memory but is slow and reduces compression ratio.
A value of 9 uses maximum memory for optimal speed. The default is 8.
property
ZlibCompressionOptions.memLevel
memLevel?: 1 | 5 | 3 | 4 | 6 | 2 | 7 | 8 | 9