Parsing of complex Symbols is slow

[skleber]

Parsing of messages according to complex symbol definitions takes ridiculous amounts of time (on an i7 machine, way over 24 hours for a 1000 messages DHCP trace).

Proposed Solution:

Introduce caching of intermediate partial parsing paths that take a long time to compute and are needed multiple times during message parsing (according to the debug output the same byte values for getDataAssignedToField get parsed with the same field definition several times).

I have tried to implement something like that but failed due to my missing understanding of how exactly the the ParsingPath is walked during the calls to MessageParser._parseBitArrayWithField().

Do you have any comment on my approach or even better: could you help me by some additional information about what's going during MessageParsing?