[Date Prev][Date Next]
[Chronological]
[Thread]
[Top]
Re: (ITS#8124) Patch "Context for compare functions"
--f46d0418253ce774cd051521cc5a
Content-Type: text/plain; charset=UTF-8
Howard thank you for taking the time to explain your reasoning.
I am curious if I were remove the conditional compilation would the patch
be more palatable.
Because usually if you are using an interpreted language you are already
taking a performance hit.
Also it only slows your program down if you use the compare functions.
If answer is still no I will just maintain the patch in my own branch.
James Rouzier.
On Sat, May 2, 2015 at 6:04 PM, Howard Chu <hyc@symas.com> wrote:
> rouzier@gmail.com wrote:
>
>> Full_Name: James Rouzier
>> Version: LMDB mdb.master
>> OS: N/A
>> URL:
>> https://github.com/rouzier/openldap/commit/33f1dc8be4a8503e78930f130ff9c8e5aa9bfa7b
>> Submission from: (NULL) (70.81.32.80)
>>
>>
>> New feature inclusion request: "Context for compare functions"
>>
>> I am finishing up a new perl module which is a very thin wrapper for LMDB.
>> (The current perl LMDB module does not fit my needs as it does not support
>> NO_TLS really support).
>>
>> When looking at mdb_set_compare and mdb_set_dupsort.
>>
>> There were three choices.
>>
>> * Not support mdb_set_compare, mdb_set_dupsort in the module.
>> * Capture each mdb_*(del|put|get) function to figure which dbi I am using.
>> * Add support for contexts in the compare functions.
>>
>> So I decided on the latter.
>>
>> I understand that passing a context for each compare can add some
>> overhead.
>> So I made this feature optional it is only enabled if the macro
>> MDB_CMP_CTX is
>> enabled.
>>
>
> I don't see supporting compare functions in interpreted languages being a
> realistic/worthwhile thing to do. The difference in performance is orders
> of magnitude.
>
> I also don't believe such conditional compilation is a good idea. LMDB is
> designed to be simple, to have very few options, and to Just Work the same
> on every platform. Conditionally compiled features are horrible because you
> can't guess which features will be present in a system-installed library.
>
> --
> -- Howard Chu
> CTO, Symas Corp. http://www.symas.com
> Director, Highland Sun http://highlandsun.com/hyc/
> Chief Architect, OpenLDAP http://www.openldap.org/project/
>
--f46d0418253ce774cd051521cc5a
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
<div dir=3D"ltr"><div class=3D"gmail_quote"><div dir=3D"ltr">Howard thank y=
ou for taking the time to explain your reasoning.<div><br></div><div>I am c=
urious if I were remove the conditional compilation would the patch be more=
palatable.</div><div>Because usually if you are using an=C2=A0<span style=
=3D"font-size:12.8000001907349px">interpreted</span>=C2=A0language you are =
already taking a performance hit.</div><div>Also it only slows your program=
down if you use the=C2=A0<span style=3D"font-size:12.8000001907349px">comp=
are functions.</span></div><div><br></div><div>If answer is still no I will=
just maintain the patch in my own branch.<span class=3D"HOEnZb"><font colo=
r=3D"#888888"><br></font></span></div><span class=3D"HOEnZb"><font color=3D=
"#888888"><div><br></div><div>James Rouzier.</div><div><br><br></div><div><=
br></div><div><br></div><div><br></div></font></span></div><div class=3D"HO=
EnZb"><div class=3D"h5"><div class=3D"gmail_extra"><br><div class=3D"gmail_=
quote">On Sat, May 2, 2015 at 6:04 PM, Howard Chu <span dir=3D"ltr"><<a =
href=3D"mailto:hyc@symas.com"; target=3D"_blank">hyc@symas.com</a>></span=
> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;bo=
rder-left:1px #ccc solid;padding-left:1ex"><a href=3D"mailto:rouzier@gmail.=
com" target=3D"_blank">rouzier@gmail.com</a> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
Full_Name: James Rouzier<br>
Version: LMDB mdb.master<br>
OS: N/A<br>
URL: <a href=3D"https://github.com/rouzier/openldap/commit/33f1dc8be4a8503e=
78930f130ff9c8e5aa9bfa7b" target=3D"_blank">https://github.com/rouzier/open=
ldap/commit/33f1dc8be4a8503e78930f130ff9c8e5aa9bfa7b</a><br>
Submission from: (NULL) (70.81.32.80)<br>
<br>
<br>
New feature inclusion request: "Context for compare functions"<br=
>
<br>
I am finishing up a new perl module which is a very thin wrapper for LMDB.<=
br>
(The current perl LMDB module does not fit my needs as it does not support<=
br>
NO_TLS really support).<br>
<br>
When looking at mdb_set_compare and mdb_set_dupsort.<br>
<br>
There were three choices.<br>
<br>
* Not support mdb_set_compare, mdb_set_dupsort in the module.<br>
* Capture each mdb_*(del|put|get) function to figure which dbi I am using.<=
br>
* Add support for contexts in the compare functions.<br>
<br>
So I decided on the latter.<br>
<br>
I understand that passing a context for each compare can add some overhead.=
<br>
So I made this feature optional it is only enabled if the macro MDB_CMP_CTX=
is<br>
enabled.<br>
</blockquote>
<br>
I don't see supporting compare functions in interpreted languages being=
a realistic/worthwhile thing to do. The difference in performance is order=
s of magnitude.<br>
<br>
I also don't believe such conditional compilation is a good idea. LMDB =
is designed to be simple, to have very few options, and to Just Work the sa=
me on every platform. Conditionally compiled features are horrible because =
you can't guess which features will be present in a system-installed li=
brary.<span><font color=3D"#888888"><br>
<br>
-- <br>
=C2=A0 -- Howard Chu<br>
=C2=A0 CTO, Symas Corp.=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0<a href=3D"=
http://www.symas.com"; target=3D"_blank">http://www.symas.com</a><br>
=C2=A0 Director, Highland Sun=C2=A0 =C2=A0 =C2=A0<a href=3D"http://highland=
sun.com/hyc/" target=3D"_blank">http://highlandsun.com/hyc/</a><br>
=C2=A0 Chief Architect, OpenLDAP=C2=A0 <a href=3D"http://www.openldap.org/p=
roject/" target=3D"_blank">http://www.openldap.org/project/</a><br>
</font></span></blockquote></div><br></div>
</div></div></div><br></div>
--f46d0418253ce774cd051521cc5a--