This pleases clang-format and makes many of these behave better when
auto formatted. Special cases may still be marked |clang-format off| in
later commits.
Differential Revision: https://phabricator.services.mozilla.com/D12231
--HG--
extra : moz-landing-system : lando
Entry storage allocation now occurs on the first lookupForAdd()/put()/putNew().
This removes the need for init() and initialized(), and matches how
PLDHashTable/nsTHashtable work. It also removes the need for init() functions
in a lot of types that are built on top of mozilla::Hash{Map,Set}.
Pros:
- No need for init() calls and subsequent checks.
- No memory allocated for empty tables, which are not that uncommon.
Cons:
- An extra branch in lookup() and lookupForAdd(), but not in put()/putNew(),
because the existing checkOverloaded() can handle it.
Specifics:
- Construction now can take a length parameter.
- init() is removed. Explicit length-setting, when necessary, now occurs in the
constructors.
- initialized() is removed.
- capacity() now returns zero when the entry storage is absent.
- lookupForAdd() is no longer `const`, because it can instantiate the storage,
which requires modifications.
- lookupForAdd() can now return an invalid AddPtr in two cases:
- old: hashing failure (due to OOM in the hasher)
- new: OOM while instantiating entry storage
The existing failure handling paths for the old case work for the new case.
- clear(), finish(), and clearAndShrink() are replaced by clear(), compact(),
and reserve(). The old compactIfUnderloaded() is also removed.
- Capacity computation code is now in its own functions, bestCapacity() and
hashShift(). setTableSizeLog2() is removed.
- uint32_t is used throughout for capacities, instead of size_t, for
consistency with other similar values.
- changeTableSize() now takes a capacity instead of a deltaLog2, and it can now
handle !mTable.
Measurements:
- Total source code size is reduced by over 900 lines. Also, lots of existing
lines got shorter (i.e. two checks were reduced to one).
- Executable size barely changed, down by 2 KiB on Linux64. The extra branches
are compensated for by the lack of init() calls.
- Speed changed negligibly. The instruction count for Bench_Cpp_MozHash
increased from 2.84 billion to 2.89 billion but any execution time change was
well below noise.
It's identical to mozilla::CStringHasher.
Also fix a comment at the top of HashTable.h about CStringHasher.
--HG--
extra : rebase_source : 92176c4f6ea8041f309764b4ce0271a494853a7b
This was done automatically replacing:
s/mozilla::Move/std::move/
s/ Move(/ std::move(/
s/(Move(/(std::move(/
Removing the 'using mozilla::Move;' lines.
And then with a few manual fixups, see the bug for the split series..
MozReview-Commit-ID: Jxze3adipUh
This also introduces JS::GetObjectRealmOrNull, which returns an object's realm,
or null if the object is a cross-compartment wrapper. In the new order,
wrappers can't have realms, since they must be shared across all realms in a
compartment. We're introducing this new function early (even though it's
*currently* possible to assign a realm to wrappers) in order to see in
advance if the possibility of returning null will cause problems.
(It looks like it won't.)
--HG--
extra : rebase_source : e55ebbbc4edf2a18ce267198928246592060e339
extra : source : d6bfce1187aa13dbfab03f9566ff7b05b6705e70
Jan de Mooij
Ted Campbell
Nicholas Nethercote
Matthew Gaudet
Emilio Cobos Álvarez
Robin Templeton
Jeff Walden
Andi-Bogdan Postelnicu
Bogdan Tara
Andreea Pavel
Luke Wagner
Brindusan Cristian
Jason Orendorff
André Bargull
Andrew McCreight
Jon Coppeard
Hannes Verschore
Shu-yu Guo
Brian Hackett
Benjamin Bouvier