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--089e0122f088ff170a05289e975e Content-Type: text/plain; charset=UTF-8 [snip] > Hypothetically, I think the best compromise is a format which has a > lossless translation between text and binary representations. > The last time we discussed this, there was some semblance of a consensus that we could use YAML or JSON as a text format, with possible translation to sqlite for a binary format. > In reality, the speed issue is for the most part irrelevant to us. We > simply don't have the quantity of floating point numerical data in our > files to cause enough slow down to warrant > > For processing 3D step files - two approaches... 1. Don't perform the > conversion unless the number is needed (shunt strings in and out of the > system). 2. Test out the idea of hashing and caching conversions.... I've a > suspicion that many coordinates and vectors get repeated a lot.... (The > Autodesk dwg format special cases 0.0 and 1.0 with a very short bit pattern > (3 bits I recall), which gives them enough reduction in file size to make > it worth while for them. > > (Btw... Anyone else react with a "wtf" to realise that the DWG binary > format operates on a literal BIT stream? - ie. Not even byte alignment!) > Fun. Britton --089e0122f088ff170a05289e975e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><br><div class=3D"gmail_extra">[snip]<br><div class=3D"gma= il_quote"><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;bord= er-left:1px #ccc solid;padding-left:1ex"><p dir=3D"ltr">Hypothetically, I t= hink the best compromise is a format which has a lossless translation betwe= en text and binary representations.</p></blockquote><div style=3D"">The las= t time we discussed this, there was some semblance of a consensus that we c= ould use YAML or JSON as a text format, with possible translation to sqlite= for a binary format.</div><blockquote class=3D"gmail_quote" style=3D"margi= n:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <p dir=3D"ltr">In reality, the speed issue is for the most part irrelevant = to us. We simply don't have the quantity of floating point numerical da= ta in our files to cause enough slow down to warrant<br></p> <p dir=3D"ltr">For processing 3D step files - two approaches... 1. Don'= t perform the conversion unless the number is needed (shunt strings in and = out of the system). 2. Test out the idea of hashing and caching conversions= .... I've a suspicion that many coordinates and vectors get repeated a = lot.... (The Autodesk dwg format special cases 0.0 and 1.0 with a very shor= t bit pattern (3 bits I recall), which gives them enough reduction in file = size to make it worth while for them.</p> <p dir=3D"ltr">(Btw... Anyone else react with a "wtf" to realise = that the DWG binary format operates on a literal BIT stream? - ie. Not even= byte alignment!)</p></blockquote><div style=3D"">Fun.</div><div>=C2=A0</di= v><div style=3D"">Britton</div></div></div></div> --089e0122f088ff170a05289e975e--
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