bitbake: bitbake: move extra cache collection out of cooker

The collection of the extra caching data should not
be performed by the cooker, but supplied to it.
This patch will also streamline the code for launching servers
without a UI attached.

Based on a patch by Bogdan Marinescu <bogdan.a.marinescu@intel.com>

(Bitbake rev: f0b54280a6bce522508e4741e5f507bc284113a8)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/bin/bitbake

@@ -75,6 +75,18 @@ def get_ui(config):
         sys.exit("FATAL: Invalid user interface '%s' specified.\n"
                  "Valid interfaces: depexp, goggle, ncurses, hob, knotty [default]." % interface)
 
+def gather_extra_cache_data():
+    extra = []
+    interfaces = ['depexp', 'goggle', 'ncurses', 'hob', 'knotty']
+    for i in interfaces:
+        try:
+            ui = __import__("bb.ui." + i, fromlist = [i])
+            if hasattr(ui, "extraCaches"):
+                extra = extra + ui.extraCaches
+            del ui
+        except:
+            pass
+    return extra
 
 # Display bitbake/OE warnings via the BitBake.Warnings logger, ignoring others"""
 warnlog = logging.getLogger("BitBake.Warnings")
@@ -237,6 +249,12 @@ def main():
 
     try:
         configuration.setServerRegIdleCallback(server.getServerIdleCB())
+
+        if configParams.server_only:
+            configuration.extra_caches = gather_extra_cache_data()
+        else:
+            configuration.extra_caches = getattr(ui_module, "extraCaches", [])
+
         cooker = bb.cooker.BBCooker(configuration)
 
         server.addcooker(cooker)