Like the hook directory, we primarily need a way to communicate this
directory between various components, but we may as well let the user
configure it.
Most of the diff is generalizing choose_hook_dir to work for both
backup and hook directories.
Choose sibling directory of xapian database, as .notmuch may not
exist.
libgen.h is already used in debugger.c, so it is not a new dependency
/ potential portability problem.
This changes some error reporting, either intentionally by reporting
the highest level missing directory, or by side effect from looking in
XDG locations when given null database location.
The main functionality will be tested when notmuch-new is converted to
support split configuration. Here only the somewhat odd case of split
mail root which is actually symlinked to the database path is tested.
Introduce a new configuration value for the mail root, and use it to
locate mail messages in preference to the database.path (which
previously implied the mail messages were also in this location.
Initially only a subset of the CLI is tested in a split
configuration. Further changes will be needed for the remainder of the
CLI to work in split configurations.
The idea is to allow reuse in n_d_create_with_config. This is
primarily code movement, with some changes in error messages to reduce
the number of input parameters.
This is slightly more tidy, but more importantly it allows for re-use
of this code in n_d_create_with_config. That re-use will be crucial
when we no longer call n_d_open_with_config from
n_d_create_with_config.
This removes duplication between the struct element and the
configuration string_map entry. Create a simple wrapper for setting
the database path that makes sure the trailing / is stripped.
In the future Xapian will apparently support this more conveniently
for the cases other than READ_ONLY => READ_ONLY
Conceptually this function seems to fit better in lib/open.cc;
database.cc is still large enough that moving the function makes
sense.
This will allow re-opening in a different mode (read/write
vs. read-only) with current Xapian API. It will also prove useful when
updating the compact functions to support more flexible database
location.
This will allow client code to provide more meaningful diagnostics. In
particular it will enable "notmuch new" to continue suggsting the user
run "notmuch setup" to create a config after "notmuch new" is
transitioned to the new configuration framework.
Fill in the remainder of the documented functionality for
n_d_open_with_config with respect to config file location. Similar
searching default locations of the database file still needs to be
added.
The main goal is to allow configuration information to be temporarily
overridden by a separate config file. That will require further
changes not in this commit.
The performance impact is unclear, and will depend on the balance
between number of queries and number of distinct metadata items read
on the first call to n_d_get_config.
