ObjFW  History of src/OFMapTable.m of 80ae736f4df39757

This uses the same format as OFEnsure(). file: [2885d27493] check-in: [c86b8f10f0] user: js, branch: trunk, size: 16601 [annotate] [blame] [check-ins using] [diff]

This essentially made it a shift rather than a rotate, sometimes
shifting most or even all of the bits out and making all hashes collide. file: [0eba9a13be] check-in: [ae4879fe0d] user: js, branch: trunk, size: 16598 [annotate] [blame] [check-ins using] [diff]

This is only migrating some places, others will be migrated as they are
touched. file: [9ddf5a7d27] check-in: [a0fd103a0b] user: js, branch: trunk, size: 16291 [annotate] [blame] [check-ins using] [diff]

The new names should be more accurate. file: [6adf8ae2bb] check-in: [627511b032] user: js, branch: trunk, size: 16398 [annotate] [blame] [check-ins using] [diff]

The internal hash is still 32 bit in most places, but this way, it is at
least not baked into the API and ABI and can be upgraded later, should
that ever be necessary. file: [8775708778] check-in: [aeb403a1ed] user: js, branch: trunk, size: 16545 [annotate] [blame] [check-ins using] [diff]

It's not very useful and is a problem for the Foundation bridge, as
NSEnumerator does not have it. file: [889ef07313] check-in: [7214a2c7af] user: js, branch: trunk, size: 16389 [annotate] [blame] [check-ins using] [diff]

This does *NOT* provide cryptographically secure randomness! file: [021ca59238] check-in: [a2a06d372a] user: js, branch: trunk, size: 16714 [annotate] [blame] [check-ins using] [diff]

Instead, explicitly declare them, as OF_ASSUME_NONNULL_{BEGIN,END} does
not apply to implicit return types. This means that after this commit,
all init methods have a nonnull return type, as they should have. file: [18b269539e] check-in: [2f4e0df8be] user: js, branch: trunk, size: 16996 [annotate] [blame] [check-ins using] [diff]

This matches Apple's style. file: [9a08c57256] check-in: [6b77a5dd8b] user: js, branch: trunk, size: 16841 [annotate] [blame] [check-ins using] [diff]

Casts are now written like types in variable declarations. file: [0faf59214b] check-in: [4af49a13c3] user: js, branch: trunk, size: 16814 [annotate] [blame] [check-ins using] [diff]

Forgot to add 2017, even though I already did quite some changes in
2017. file: [69937f5d0f] check-in: [44f45c2e35] user: js, branch: trunk, size: 16788 [annotate] [blame] [check-ins using] [diff]

The reason for this is that -[valueForKey:] could be confused with
Key Value Coding. file: [f6af531a58] check-in: [1ba9c051a6] user: js, branch: trunk, size: 16782 [annotate] [blame] [check-ins using] [diff]

While at it, also update the mail address. file: [32a1b1967d] check-in: [cec0f072f8] user: js, branch: 0.8, size: 16797 [annotate] [blame] [check-ins using] [diff]

While at it, also update the mail address. file: [0f58c455bb] check-in: [2a27cf3000] user: js, branch: trunk, size: 16694 [annotate] [blame] [check-ins using] [diff]

Now that we can require GCC >= 4.6, we no longer need to fall back to
using a category on old compilers. file: [a593ea3dae] check-in: [2aca549d60] user: js, branch: trunk, size: 16690 [annotate] [blame] [check-ins using] [diff]

This increases the required GCC version from 4.0 to 4.6 (exception:
Apple GCC, which already supports this with >= 4.0 starting with OS X
10.5). Since even GCC 4.6 is really old by now, there is no point in
still supporting something even older and making the code ugly because
of that. While some hardware and OS support was dropped from GCC 4.6
compared to GCC 4.0, there is nothing in there that would be an
interesting target with the exception of BeOS maybe - but a port to BeOS
can also be achieved using the Haiku support. The other dropped OSes are
mostly old versions of OSes while newer ones are still being supported
(and those newer versions of those OSes still support the same
hardware). file: [1fa0a57947] check-in: [48980f2297] user: js, branch: trunk, size: 16728 [annotate] [blame] [check-ins using] [diff]

This means that OFObject.h imports macros.h now, making it unnecessary
to manually import macros.h in almost every file. And while at it, also
import autorelease.h in OFObject.h, so that this doesn't need to be
manually imported in almost every file as well. file: [bf79826698] check-in: [13ee56edf3] user: js, branch: trunk, size: 16771 [annotate] [blame] [check-ins using] [diff]

Instead, just define _GNU_SOURCE when __GLIBC__ is defined. After all,
that's the only libc that doesn't work properly without any defines. file: [3156715ede] check-in: [17be12b6e5] user: js, branch: trunk, size: 16788 [annotate] [blame] [check-ins using] [diff]

Not using -std=gnu11 means _GNU_SOURCE does not get defined anymore,
therefore this commit also adds the required feature defines for glibc.

Additionally, this adds of_strdup in macros.h, as strdup is an
extension. file: [dffae0d500] check-in: [2f5af58573] user: js, branch: trunk, size: 16742 [annotate] [blame] [check-ins using] [diff]

A file documenting the coding style will be written soon. This will
hopefully prevent conflicts in the future, such as whether static
functions are written in camelCase or_with_underscores, like was the
case here. file: [8882363f15] check-in: [fa6496efc7] user: js, branch: trunk, size: 16715 [annotate] [blame] [check-ins using] [diff]

This mostly removes the argument for the class in which the exception
occurred. As backtraces were recently added for all platforms, the
passed class does not give any extra information on where the exception
occurred anymore.

This also removes a few other arguments which were not too helpful. In
the past, the idea was to pass as many arguments as possible so that it
is easier to find the origin of the exception. However, as backtraces
are a much better way to find the origin, those are not useful anymore
and just make the exception more cumbersome to use. The rule is now to
only pass arguments that might help in recovering from the exception or
provide information that is otherwise not easily accessible. file: [40dcf1c644] check-in: [3d16a30f41] user: js, branch: trunk, size: 15634 [annotate] [blame] [check-ins using] [diff]

This also removes "bool *stop" from some blocks where it does not make
sense. file: [7caa69a7b0] check-in: [e8473b9db8] user: js, branch: trunk, size: 16124 [annotate] [blame] [check-ins using] [diff]

The only places where BOOL is left are those where they are required by
the ABI. file: [f2d7d60333] check-in: [c5ef582958] user: js, branch: trunk, size: 16136 [annotate] [blame] [check-ins using] [diff]

This was already implemented in OFDictionary_hashtable for internal
usage and is now publicly available. file: [1f61a324ed] check-in: [4fb0f4bf66] user: js, branch: trunk, size: 16106 [annotate] [blame] [check-ins using] [diff]

This makes the map table use the full range of the hash and not only the
least significant bits, making it harder for an attacker to find
collisions. file: [3a2a927b76] check-in: [7cebeaa808] user: js, branch: trunk, size: 15886 [annotate] [blame] [check-ins using] [diff]

This reverts:
* "Add a per-hashtable seed."
(cd49c7fcb4b8dca62dccdbf6545d37d86b639eef)
* "OFMapTable: Reseed on resize."
(5b545165691cd9ad838c9125b02ff7c857bd4b99)
* "Add of_random()."
(9810f191b4e8c1612e7e55095c87e589660fbdba)
* "OFMapTable: Rotate hash by a random number of bits"
(3bef412217232d01f202794f7175c130afa1df8f)

It turned out that these were slowing down all classes based on
OFHashMap significantly. As there is still no proof that the seeded
one-at-a-time hash is vulnerable to DoS, these changes were overly
paranoid. While overly paranoid is usually ok, it is not if it severely
impacts performance. file: [458807374d] check-in: [6712442fad] user: js, branch: trunk, size: 15686 [annotate] [blame] [check-ins using] [diff]

By rotating the hash by a random number of bits, an attacker needs to
find collisions on the full 32 bits of the hash and not only on the
lower n bits that are actually used by the map table, as an attacker
can't know which bits are actually used for the map table. file: [fda4d04529] check-in: [4857107479] user: js, branch: trunk, size: 16362 [annotate] [blame] [check-ins using] [diff]

This should make it impossible to retrieve of_hash_seed by inserting
keys into a hashtable and then retrieving the hashtable. Without this
change, the order could be used to make guesses about of_hash_seed,
which could be a problem for long running processes. file: [fac29d9273] check-in: [590fa6ed79] user: js, branch: trunk, size: 16029 [annotate] [blame] [check-ins using] [diff]