The way the various properties[] arrays are initialized is inefficient:
- only the .data members change at runtime, yet the whole arrays of
properties with all the fields are constructed on the stack one by
one by the code.
- there's duplication, eg. the properties of "org.freedesktop.systemd1.Unit"
are repeated in several unit types.
Fix it by moving the information about properties into static const
sections. Instead of storing the .data directly in the property, store
a constant offset from a run-time base.
The small arrays of struct BusBoundProperties bind together the constant
information with the right runtime information (the base pointer).
On my system the code shrinks by 60 KB, data increases by 10 KB.
Now that objects of all unit types are allocated the exact amount of
memory they need, the Unit union has lost its purpose. Remove it.
"Unit" is a more natural name for the base unit class than "Meta", so
rename Meta to Unit.
Access to members of the base class gets simplified.
When we merge units that some kind of object points to, those pointers
might become invalidated, and needs to be updated. Introduce a UnitRef
struct which links up all the unit references, to ensure corrected
references.
At the same time, drop configured_sockets in the Service object, and
replace it by proper UNIT_TRIGGERS resp. UNIT_TRIGGERED_BY dependencies,
which allow us to simplify a lot of code.
When cross-compiling systemd, the introspection XML files fail to be
generated because the systemd host binary is not executable. This patch
works around this by putting the introspection XML data into separate
ELF sections and extracting them from the binary when generating the XML
files.
The extracted XML data is passed through the strings utility in order to
strip the trailing NUL character. A small AWK script is used to prepend
the doctype and add the opening and closing node tags respectively.
Finally, the C preprocessor is used to substitute the correct doctype
information from the D-Bus header files.
