## Problem
Split off from https://github.com/neondatabase/neon/pull/7399, which is
the first piece of code that does a WithDelimiter object listing using a
prefix that isn't a full directory name.
## Summary of changes
- Revise list function to not append a `/` to the prefix -- prefixes
don't have to end with a slash.
- Fix local_fs implementation of list to not assume that WithDelimiter
case will always use a directory as a prerfix.
- Remove `list_files`, `list_prefixes` wrappers, as they add little
value and obscure the underlying list function -- we need callers to
understand the semantics of what they're really calling (listobjectsv2)
Cancellation and timeouts are handled at remote_storage callsites, if
they are. However they should always be handled, because we've had
transient problems with remote storage connections.
- Add cancellation token to the `trait RemoteStorage` methods
- For `download*`, `list*` methods there is
`DownloadError::{Cancelled,Timeout}`
- For the rest now using `anyhow::Error`, it will have root cause
`remote_storage::TimeoutOrCancel::{Cancel,Timeout}`
- Both types have `::is_permanent` equivalent which should be passed to
`backoff::retry`
- New generic RemoteStorageConfig option `timeout`, defaults to 120s
- Start counting timeouts only after acquiring concurrency limiter
permit
- Cancellable permit acquiring
- Download stream timeout or cancellation is communicated via an
`std::io::Error`
- Exit backoff::retry by marking cancellation errors permanent
Fixes: #6096Closes: #4781
Co-authored-by: arpad-m <arpad-m@users.noreply.github.com>
Do list-delete operations in batches instead of doing full list first, to ensure
deletion makes progress even if there are a lot of files to remove.
To this end, add max_keys limit to remote storage list_files.
The remote_storage crate contains two copies of each test, one for azure
and one for S3. The repetition is not necessary and makes the tests more
prone to drift, so we remove it by moving the tests into a shared
module.
The module has a different name depending on where it is included, so
that each test still has "s3" or "azure" in its full path, allowing you
to just test the S3 test or just the azure tests.
Earlier PR that removed some duplication already: #6176Fixes#6146.
The PR does two things:
* move the util functions present in the remote_storage Azure and S3
test files into a shared one, deduplicating them.
* add a `s3_upload_download_works` test as a copy of the Azure test
The goal is mainly to fight duplication and make the code a little bit
more generic (like removing mentions of s3 and azure from function
names).
This is a first step towards #6146.
