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Date: Thu, 4 Oct 2012 09:19:19 -0700 (PDT)
From: Jimb Esser <wastel...@gmail.com>
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Subject: Re: [nodejs] Array reads faster than Buffer reads ???
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If you want *really* fast buffer access for larger integer types and float 
types, you can set up a native module that 
calls SetIndexedPropertiesToExternalArrayData a few times on your Buffer 
and gives you a native indexed view into the buffer for whatever primitive 
type you want to read (much, much, much faster than trying to read a float 
byte-by-byte and assemble it).  We do this in our internal networking 
buffers, and got quite a speed-up compared to combining bytes in JS (though 
either are *way* faster than calling into native methods to do the read, 
except maybe with floats).  Note: for un-aligned reads (e.g. reading a 
64-bit float from 3 bytes within a buffer), I think this only works on some 
platforms, but those platforms include x86 and x64, which is all we care 
about in our case.

  Jimb Esser
  Cloud Party

On Wednesday, October 3, 2012 5:38:38 PM UTC-7, NodeNinja wrote:
>
>
>
> On Thursday, October 4, 2012 5:44:16 AM UTC+5:30, Ben Noordhuis wrote:
>>
>> They won't, they're there mostly for convenience*.
>>
>
> Now that's an* eye opener* Ben!
> I hope that line finds its way to the documentation.
> Many thanks!!
>
>
>
>
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If you want *really* fast buffer access for larger integer types and float =
types, you can set up a native module that calls&nbsp;SetIndexedPropertiesT=
oExternalArrayData a few times on your Buffer and gives you a native indexe=
d view into the buffer for whatever primitive type you want to read (much, =
much, much faster than trying to read a float byte-by-byte and assemble it)=
. &nbsp;We do this in our internal networking buffers, and got quite a spee=
d-up compared to combining bytes in JS (though either are *way* faster than=
 calling into native methods to do the read, except maybe with floats). &nb=
sp;Note: for un-aligned reads (e.g. reading a 64-bit float from 3 bytes wit=
hin a buffer), I think this only works on some platforms, but those platfor=
ms include x86 and x64, which is all we care about in our case.<div><br></d=
iv><div>&nbsp; Jimb Esser</div><div>&nbsp; Cloud Party<br><br>On Wednesday,=
 October 3, 2012 5:38:38 PM UTC-7, NodeNinja wrote:<blockquote class=3D"gma=
il_quote" style=3D"margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid=
;padding-left: 1ex;"><br><br>On Thursday, October 4, 2012 5:44:16 AM UTC+5:=
30, Ben Noordhuis wrote:<blockquote class=3D"gmail_quote" style=3D"margin:0=
;margin-left:0.8ex;border-left:1px #ccc solid;padding-left:1ex">They won't,=
 they're there mostly for convenience*.<br></blockquote><div><br></div><div=
>Now that's an<b> eye opener</b> Ben!</div><div>I hope that line finds its =
way to the documentation.</div><div>Many thanks!!</div><div><br></div><div>=
<br></div><div><br></div></blockquote></div>
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