a090706421
This commit adds an http server and client for streaming snapshots and WAL pages from an upstream Litestream primary to a read-only replica.
WAL Writer Live
This test is to ensure we can copy a WAL file into place with a live DB and trigger a checkpoint into the main DB file.
To reproduce the data files:
$ sqlite3 db
sqlite> PRAGMA journal_mode = 'wal';
sqlite> CREATE TABLE t (x);
sqlite> PRAGMA wal_checkpoint(TRUNCATE);
sqlite> INSERT INTO t (x) VALUES (1);
sqlite> CTRL-\