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<div class="moz-cite-prefix">Il 12/03/2013 17:41, Peter K ha
scritto:<br>
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<blockquote cite="mid:513F5AB0.8080301@yahoo.de" type="cite">
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<div class="moz-cite-prefix">Hi Ottavio,<br>
<br>
thanks for reaching out. That is still on the todo list. I would
be very happy for your contribution! But you'll have to digg
deep into GraphHopper - just to warn you ;)<br>
<br>
See the newly created issue: <a moz-do-not-send="true"
class="moz-txt-link-freetext"
href="https://github.com/graphhopper/graphhopper/issues/23">https://github.com/graphhopper/graphhopper/issues/23</a><br>
<br>
Let me know if you need assistance or further details. I could
probably do the first step relative fast in a separate
instructions branch if that would help a bit.<br>
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<br>
Hello Peter,<br>
<br>
yesterday I studied the issue #23 and I think that the second and
the third point are clear,<br>
<br>
I think that the first point is not clear. Let me explain: you say
that you would like to add a DataAccess to GraphStorage. If I
correctly understand, the DataAccess interface is a way to access
the graph information. I don't understand why you think that
changing the access from int to byte would be sufficient to have it
implemented.<br>
<br>
I've read <a class="moz-txt-link-freetext" href="https://github.com/graphhopper/graphhopper/wiki/Developers">https://github.com/graphhopper/graphhopper/wiki/Developers</a>
, and I have some questions about the data layout:<br>
<ol>
<li>do nodes correspond to the nodes of OSM? In the picture of the
data layout I don't understand the meaning of the arrows that go
from the nodes to the edges.</li>
<li>are the edges the adjacency of the nodes? The would explain
nextA and nextB, but I don't understand why in the picture you
have the nodes 0 and 3 pointing to the same row.</li>
<li>what is the meaning of nodeA and nodeB? and what does
nodeA<nodeB mean? Really, I tried to understand but I was not
able to get the structure.</li>
<li>Finally, do properties have a fixed length? Do you plan to
store the name of the stree there? But I think that this
solution would duplicate the name of the street for all the
nodes. Would it be more efficient to store an offset for the
content of a file holding all the names of the street?</li>
</ol>
<p>my idea is to create another file, let's call it names, with all
the street names and to add an offset for each node so that it
would be fast to retrieve the name of the streets when the
evaluated path is converted to instructions. Can you please
explain me how you thought about using a byte-oriented DataAccess
to handle the street names?<br>
</p>
<p>Ottavio<br>
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