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= Sharing Archives =

 * Audience: Users who want to share binary archives between machines
 * Requires: MacPorts >= ?? (whenever archive support was added)

== Introduction ==

For those of you fortunate enough to have access to more than one Mac to work from, here's a quick way to save yourself '''a lot''' of compiling time. What we're basically going to do here is configure macports to use the archive system, and then copy over archives as we need them. (Or, you can use rsync to always keep the two in sync.) The other thing we'll also go over is how to share archives between two machines that use a different architecture.

== Common Configuration Steps ==

=== '''Enable Archive Mode''' ===

For starters, lets edit your {{{macports.conf}}} file and enable archive mode. Your {{{macports.conf}}} is found in {{{${prefix}/etc/macports/macports.conf}}}. For most people, this will be {{{/opt/local/etc/macports/macports.conf}}}. Edit this file in your editor of choice and look for {{{portarchivemode}}}. It will probably be set to {{{no}}} by default. Change it to a {{{yes}}} and then save the file.

== Share archives between identical architectures ==

If you're using two machines that are both the same architecture (''i386'' or ''powerpc'') then you have it relatively easy. Lets say that you want to copy a compiled copy of ''sqlite3'' over to your other machine. We'll use the terms __source__ and __target__ to describe the two machines here. The __source__ is the machine that already has the package installed. 
=== Build the archive on the __source__ machine ===
{{{
sudo port archive sqlite3
}}}
=== Install the archive on the __target__ machine ===
Now if you look on your __source__ machine in {{{ ${prefix}/var/macports/packages/darwin/${arch} }}} (where ${arch} is either ''i386'' or ''powerpc'') you should find a file named {{{sqlite3-x.x.x_x.i386.tgz}}}. (The x's are the version number.) Copy that file to the same location on your __target__ machine. Now on the __target__ do:
{{{
sudo port unarchive sqlite3
}}}
followed by:
{{{
sudo port install sqlite3
}}}
And you're done! Easy huh? :)

Note: AFAIK the unarchive step should '''not''' be necessary, but I've been unable to get it to work without it. If you have more information on this please feel free to post it here.

== Share archives between '''different''' architectures ==

'''WARNING!!! ''' Sharing archives between different architectures could, in theory, seriously '''b0rk''' your system! You have been warned!

Now, here's the fun part. Say you have an ''i386'' machine and a ''powerpc'' machine. Chances are that the ''i386'' machine is a fair bit faster. But you can't share binaries between them... or can you? Thanks to the '''+universal''' variant, it's possible. Here's a good primer on [[wiki:howto/buildUniversal building universal binaries]].

Unfortunately, just doing this is not enough. The archive system still knows where the archive was built, so by default a ''powerpc'' system will not use an ''i386'' archive and vice versa. So what do we do? Well, we start with the simple steps. We'll be using the same example as above (''sqlite3'') going from a __source__ ''i386'' machine to a __target__ ''powerpc'' machine.

=== Build the archive on the __source__ machine ===
{{{
sudo port archive sqlite3 +universal
}}}
=== Install the archive on the __target__ machine ===
Now we're going to copy the file to the same location on the target machine. On our source machine we're going to find the file {{{/opt/local/var/macports/packages/darwin/i386/sqlite3-x.x.x_x+universal.i386.tgz}}} We're going to copy that file to the __target__ machine. But the __target__ won't have the appropriate directory, since it's a different architecture. So we're going to copy it into {{{/opt/local/var/macports/packages/darwin/powerpc/}}} instead.

You'll also notice that the archive has the architecture in the name. So we'll need to change that as well. Just rename the file and change ''i386'' to ''powerpc''. The new name should be something like {{{sqlite3-x.x.x_x+universal.powerpc.tgz}}}.

Finally, we can proceed with the installation:
{{{
sudo port unarchive sqlite3 +universal
}}}
followed by:
{{{
sudo port install sqlite3 +universal
}}}
Note that we're specifying the variant in both cases. Otherwise the commands wouldn't find the archive file and this wouldn't work. (Because the archive file has ''+universal'' in the name.)

So that's it! Enjoy! :)
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