|___HXXXSSSXXXXXXXTDD__|
H: Head position (first readable byte)
T: Tail position (first writeable byte)
X: Uninvolved bytes in the readable section
S: Source bytes, to be copied at the end of the buffer
D: Destination bytes, going to be written to by copying the source bytes
_: Uninvolved bytes in the writable section

|D__HXXXSSSSSSSXXXTDDDD|

|XXSSSSSXXXXXTDDDD__HXX|

|SSSXXTDDDD__HXXXXXXXSS|

// continuous data:
//
//            H           T
// Read:  ____XXXXSSSSXXXX________
// Write: ________________DDDD____
//
// H: Head position (first readable byte)
// T: Tail position (first writable byte)
// X: Uninvolved bytes in the readable section
// S: Source bytes, to be copied to D bytes
// D: Destination bytes, going to be copied from S bytes
// _: Uninvolved bytes in the writable section

test src/encoding/frame_encoder.rs - encoding::frame_encoder::FrameCompressor (line 44) ... FAILED
test src/frame_decoder.rs - frame_decoder::FrameDecoder (line 28) ... FAILED