Looks like Cypres vine, Ipomoea x quamoclit. Here is a link that might be useful: Ipomoea x ...

When you say it must be self supporting do you mean self clinging like ivy? If so that reduces your choices. Or are you prepared to provide a few wires or hooks? This rose is Goldfinch. It had one loop of wire to start it off. There is also a Clematis montana on the other side which has a couple of wires across the roof. It flowers earlier, along with the apple blossom. I don’t know whether these choices would work in S California. This one is Solanum ‘Glasnevin’. Not over a roof but it would work there. Again just a couple of wires needed.

the problem with vines in the compost pile is the woody vine itself .. if it becomes so .... the suggested ID is the grape family ... and they are the worst .. they take usually take forever to break down ... and make turning the pile near impossible.. unless you really like cussing while you do so ... which in itself can be therapeutic .. lol ... when i took down some large grape plants.. i made dozens of xmas wreaths out of them.. just by winding them up ... i gave them away to everyone who walked in the yard.. lol .. now that recycling ... lol https://duckduckgo.com/?t=ffab&q=grape+vine+wreaths&iax=videos&ia=videos ken

Thank you; that's it exactly. It self propagates each year. I'm glad the hummingbirds like it!