The previous iterator was implemented to simply fetch _all_ pathes from
the filesystem, no matter what.
With this implementation, this changes. The iterator now has
functionality to optimize the iteration, if only a subdirectory of the
store is required, for example `$STORE/foo`.
This is done via functionality where the underlying iterator gets
altered.
First of all, the interface was changed to return a `Entries` object,
which itself only covers the libimagstore-internal `PathIterator` type.
This type was changed so that the backend implementation provides an
"PathIterBuilder`, which builds the actual iterator object for the
`PathIterator` type.
The intermediate `StoreIdConstructingIterator` was merged into
`PathIterator` for simplicity.
The `Entries` type got functionality similar to the
`StoreIdIteratorWithStore` type for easier transition to the new API.
This should probably be removed at a later point, though.
As the `walkdir::WalkDir` type is not as nice as it could be, iterators
for two collections in the store could be built like this (untested):
store
.entries()?
.in_collection("foo")
.chain(store.entries()?.in_collection("bar"))
Functionality to exclude subdirectories is not possible with the current
`walkdir::WalkDir` implementation and has to be done during iteration,
with filtering (as usual).
Signed-off-by: Matthias Beyer <mail@beyermatthias.de>
Refactor error handling so we do chain the error with the `?`
operator rather than wrapping it with own types.
Links to other error chains are created with error chain. All unneeded
error kinds were removed.
No API changes.
Before we extracted the store configuration from the configuration
toml::Value object and passed it to the store.
This is unecessary overhead.
Now we pass the whole configuration object and let the store extract the
required values.
Matthias Beyer