Don't log errors returned by server.Shutdown. They are exceedingly
unlikely, and there is nothing which can be done about them.
Moving the "Listening on..." log closer to where the server is actually
started reduces the chance of confusion. Also, logging the parsed
listener.Addr() string instead of the provided config string provides
extra debugging detail.
The server will shutdown cleanly even if the passed context is already
canceled, so there is no need to pass a new context and blindly guess at
how long the server may need to stop.
Exporting this struct is a step towards breaking up the Start func into
a New func and Run func, enabling calling code to use:
api := webapi.New()
api.Run()
WebAPI is a more suitable name than server because it matches the
package name, and also it helps to distinguish WebAPI from the HTTP
server it uses internally (ie. webapi.server rather than server.server).
It's generally good practice to first create everything that can fail
and then create the final instance at once with the results versus doing
it piecemeal.
Piecemeal creation is typically more error prone and, while not a huge
concern here, it also ends up needlessly creating objects that are just
thrown away in the event of a later error.
Storing references to the database/dcrd/dcrwallet clients inside the
cache struct means they don't need to be passed in every time the cache
is updated.
