Hello,

I released cachetools - package with @safe and @nogc cache and hashtable implementations.

It inherits nogc propery from key toHash and opEquals methods and can store immutable keys and values (with restrictions).

Currently implemented only LRU cache with TTL.

http://code.dlang.org/packages/cachetools
https://github.com/ikod/cachetools


Performance of underlying hash table seems to be better in my benchmarks in comparison with std associative arrays and with emsi containers (see https://github.com/ikod/cachetools/tree/master/testhash )

        Test inserts and lookups int[int]
        =================================
|std     | 303 ms, 541 μs, and 3 hnsecs    | GC memory Δ 41MB|
|c.t.    | 181 ms, 173 μs, and 2 hnsecs    | GC memory Δ 0MB|
|c.t.+GC | 184 ms, 594 μs, and 5 hnsecs    | GC memory Δ 16MB|
|emsi    | 642 ms and 120 μs               | GC memory Δ 0MB|

     Test insert, remove, lookup for int[int]
     =======================================
|std     | 327 ms, 982 μs, and 1 hnsec     | GC memory Δ 17MB|
|c.t.    | 229 ms, 11 μs, and 7 hnsecs     | GC memory Δ 0MB|
|c.t.+GC | 240 ms, 135 μs, and 4 hnsecs    | GC memory Δ 16MB|
|emsi    | 678 ms, 931 μs, and 9 hnsecs    | GC memory Δ 0MB|

     Test inserts and lookups for struct[int]
     =======================================
|std     | 468 ms, 411 μs, and 7 hnsecs    | GC memory Δ 109MB|
|c.t.    | 392 ms, 146 μs, and 1 hnsec     | GC memory Δ 0MB|
|c.t.+GC | 384 ms, 771 μs, and 5 hnsecs    | GC memory Δ 88MB|
|emsi    | 1 sec, 328 ms, 974 μs, and 9 h  | GC memory Δ 0MB|

...

Thanks for bugreports and proposals.

Hello,

v.0.1.1 released.

Significant changes since previous announce:

Caches:

1. added 2Q cache. 2Q is more advanced strategy than plain LRU. It is faster, scan-resistant and can give more cache hits.

2. For LRU cache implemented per-item TTL in addition to global TTL.

Containers:

1. Added unrolled double-linked lists. Unrolled lists are much faster than plain double-linked lists. Unrolled lists used for 2Q cache implementation.

2. HashMap  - code cleanup, use core.internal.hash: bytesHash for strings.

Cachetools is set of cache strategies and containers. Caches and containers are @safe and @nogc (inherits from key and value properties).

Project page: https://github.com/ikod/cachetools
docs: https://ikod.github.io/cachetools/

Some performance test results: https://github.com/ikod/cachetools/tree/master/testhash

Hello

cachetools version 0.2.1 released

Changelog:

OrderedHashMap added to containers,
copy constructors added to containers
addIfMissed interface added to HashMap's

What is it?

cachetools - package with @safe and @nogc cache and hashtable implementations.

It inherits nogc propery from key toHash and opEquals methods and can store immutable keys and values (with restrictions).

Currently inplemented:

caches: LRU, 2Q
containers: HashMap, OrderedHashMap, unrolled list, dlist, slist

Project page: https://github.com/ikod/cachetools
docs: https://ikod.github.io/cachetools/

Some performance test results: https://github.com/ikod/cachetools/tree/master/testhash

Hello

cachetools version 0.3.1 released

Changelog:

"Set" container added (based on hashtable)
Const-ness problems for hashtable fixed.

What is it?

cachetools - package with @safe and @nogc cache and containers  implementations.

It inherits @nogc and @safe property from key toHash and opEquals methods and can store immutable keys and values (with restrictions).

Currently implemented:

caches: LRU, 2Q (with TTL)

containers: HashMap, OrderedHashMap, unrolled list, dlist, slist, set

Project page: https://github.com/ikod/cachetools
docs: https://ikod.github.io/cachetools/

Some performance test results:
https://github.com/ikod/cachetools/tree/master/testhash

On Tuesday, 13 August 2019 at 09:34:48 UTC, ikod wrote:
> Hello
>
> cachetools version 0.3.1 released
>
[...]
Looking at your performance numbers, I am wondering should your work in the end result in a better std AA implementation?

Regards mt.

On Tuesday, 13 August 2019 at 10:12:45 UTC, Martin Tschierschke wrote:
> On Tuesday, 13 August 2019 at 09:34:48 UTC, ikod wrote:
>> Hello
>>
>> cachetools version 0.3.1 released
>>
> [...]
> Looking at your performance numbers, I am wondering should your work in the end result in a better std AA implementation?
>
> Regards mt.

I'm not sure if I can say too much here. And I can be wrong, but looks like std AA allocate table bucket entry on every insert. This can hurt performance when you have mixed insert/lookup use case. If this is the case then fix will require rewrite of AA code.

Thanks and regards,
Igor

On 13.08.19 11:34, ikod wrote:
> What is it?
> 
> cachetools - package with @safe and @nogc cache and containers implementations.
[...]
> Project page: https://github.com/ikod/cachetools
> docs: https://ikod.github.io/cachetools/

They don't seem to actually be @safe. An example:

----
import cachetools.containers.lists;
import std.stdio;
void main() @safe
{
    DList!int dl;
    dl.insert_first(42);
    auto r = dl.range;
    dl.clear();
    writeln(r.front); /* Prints garbage, because it's accessing `free`d memory. */
}
----

As far as I can I see, that compiles because you have a bad @trusted here: <https://github.com/ikod/cachetools/blob/ac72aafe979e2f95a343eb9d19b1b67915e4fc17/source/cachetools/containers/lists.d#L391>.

Other containers probably have similar problems.

On Tuesday, 13 August 2019 at 17:18:23 UTC, ag0aep6g wrote:
> On 13.08.19 11:34, ikod wrote:
>> What is it?
>> 
>> cachetools - package with @safe and @nogc cache and containers implementations.
> [...]
>> Project page: https://github.com/ikod/cachetools
>> docs: https://ikod.github.io/cachetools/
>
> They don't seem to actually be @safe. An example:
>
> ----
> import cachetools.containers.lists;
> import std.stdio;
> void main() @safe
> {
>     DList!int dl;
>     dl.insert_first(42);
>     auto r = dl.range;
>     dl.clear();
>     writeln(r.front); /* Prints garbage, because it's accessing `free`d memory. */
> }
> ----
>
> As far as I can I see, that compiles because you have a bad @trusted here:

Probably this @trusted is not a problem (std.container.dlist also contain @trusted code). I mistakenly  ignored this case.

Thanks for your report, and  I'll create issue on github.

> <https://github.com/ikod/cachetools/blob/ac72aafe979e2f95a343eb9d19b1b67915e4fc17/source/cachetools/containers/lists.d#L391>.
>
> Other containers probably have similar problems.