Interval trees (wmem_itree_t) are implemented as an extension of wmem_tree with a
guint64-based range as the key.
This is useful for instance in MPTCP analysis, to look for packets
matching a range defined by a mapping across TCP subflows.
Change-Id: Iea706d44fe975e390a4191ad0257ef37d5c71525
Reviewed-on: https://code.wireshark.org/review/11714
Reviewed-by: Evan Huus <eapache@gmail.com>
Petri-Dish: Evan Huus <eapache@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Guy Harris <guy@alum.mit.edu>
This has two expected uses:
- Many current users of wmem_tree don't actually need the predecessor lookup
it provides (the lookup_le function family). A hash map provides straight
insertion and lookup much more efficiently than a wmem_tree when predecessor
lookup isn't needed.
- Many current users of glib's hash table and hash functions use untrusted data
for keys, making them vulnerable to algorithmic complexity attacks. Care has
been taken to make this implementation secure against such attacks, so it
should be used whenever data is untrusted.
In my benchmarks it is measurably slower than GHashTable, but not excessively
so. Given the additional security it provides this seems like a reasonable
trade-off (and it is still faster than a wmem_tree).
Change-Id: I2d67a0d06029f14c153eaa42d5cfc774aefd9918
Reviewed-on: https://code.wireshark.org/review/1272
Reviewed-by: Evan Huus <eapache@gmail.com>
There is confusion about API usage, and problems on my part concerning whether
keys should be compared signed or unsigned, and how to do that efficiently.
Unsigned keys in particular were behaving oddly.
Change-Id: I075693bbd04c15f79f24f9a24006003a914cc572
Reviewed-on: https://code.wireshark.org/review/924
Reviewed-by: Evan Huus <eapache@gmail.com>
This is a tree implementation intended to replace the current red-black tree in
wmem_tree (which was inherited from emem), assuming there are no regressions.
Splay trees bubble recently accessed keys to the top, and as such have a number
of very nice properties: https://en.wikipedia.org/wiki/Splay_tree
This implementation is a variant known as "independent semi-splaying", which has
better practical performance. It should do about as well as the red-black tree
for random insertions and accesses, but somewhat better for patterned accesses
(such as accessing each key in order, or accessing certain keys very
frequently).
There are a few other changes relative to the red-black tree implementation that
are worth mentioning:
- Instead of requiring complex keys to be split into guint32 chunks and doing
this weird trick with sub-trees, I let the keys be arbitrary pointers and
allowed the user to specify an arbitrary comparison function. If the function
is NULL then the pointers are compared directly for the simple integer-key
case.
- Splay trees do not need to store a red-black colour flag for each node. It is
also much easier to do without the parent pointer in each node. And due to
the simpler system for complex keys, I was able to remove the "is_subtree"
boolean. As such, splay nodes are 12 bytes smaller on 32-bit platforms, and
16 bytes smaller on a 64-bit platform.
All done in about half the lines of code.
Change-Id: I89fb57e07d2bb7e3197190c7c2597b0c5adcc03b
Reviewed-on: https://code.wireshark.org/review/758
Reviewed-by: Evan Huus <eapache@gmail.com>
(Using sed : sed -i '/^ \* \$Id\$/,+1 d')
Fix manually some typo (in export_object_dicom.c and crc16-plain.c)
Change-Id: I4c1ae68d1c4afeace8cb195b53c715cf9e1227a8
Reviewed-on: https://code.wireshark.org/review/497
Reviewed-by: Anders Broman <a.broman58@gmail.com>
The overhead is not large, and it makes append much faster (O(1) vs O(n)).
It also will make a queue easy to add, which I need for a dissector I'm
writing...
svn path=/trunk/; revision=50744
recurring callbacks, I suspect most other potential uses will be once-only, so
make that possible, and improve the documentation on the remaining issues.
Also separate out the code into its own files and the testing into its own
test case.
svn path=/trunk/; revision=49209
(removed in r48218) which did nothing particularly useful. Also lets us remove
another debugging environment variable.
svn path=/trunk/; revision=48219
yet initialized because I can't figure out where the enter() and leave() calls
should go - the obvious place in packet.c causes a lot of assertion errors.
svn path=/trunk/; revision=45879
Dario Lombardo