v0.0.54: Populate sources directly from the backend.

This improve performance of the admin UI.

v0.0.53: Synchronize importers with server regularly to avoid entropy.

Entropy can be generated while performing a migration while keeping the
service running.

v0.0.52

Fix resource overflow issue with defer.

v0.0.51: Remove unique constraint from relations table.

This aligns with the removal of the unique constraint in the assets
table.

This will likely improve performance and avoid some deadlocks faced in
production as shown below from the innodb status.

*** (2) TRANSACTION:
TRANSACTION 13224836, ACTIVE 2 sec inserting
mysql tables in use 1, locked 1
908 lock struct(s), heap size 106616, 943 row lock(s), undo log entries 1951
MySQL thread id 4405, OS thread handle 140199291565824, query id 676173554 10.236.102.30 svc-criteokb Update
INSERT INTO relations (id, from_id, to_id, type) VALUES (?, ?, ?, ?)
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 41 page no 34334 n bits 528 index unique_relation of table `criteokb`.`relations` trx id 13224836 lock_mode X locks rec but not gap
Record lock, heap no 455 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 8; hex e74f2e13ed67611d; asc  O.  ga ;;
 1: len 8; hex 7a9f7cd5e9f8c4c0; asc z |     ;;
 2: len 3; hex 686173; asc has;;
 3: len 8; hex 74af2536c993d1f2; asc t %6    ;;

v0.0.50: Add streaming support on read side.

Streaming was implemented only on the write side but when multiple data
sources requested a graph from the API, huge graph could have been
loaded in memory before being encoded and sent over the wire. With this
encoder, each relation or asset is itself encoded and sent independently
and the whole graph is reconstructed on client side.

The encoding format is definitely not optimized yet since it uses json
format and duplicated assets could be sent multiple times but that is
worth it considering the amount of memory saved. The deduplication is
done on the client side anyway.

v0.0.49

Bump antlr driver to try avoiding memory leak

v0.0.48

Remove new lines in log lines.

v0.0.47

Add pprof capabilities to the binary.

v0.0.46: Forward API errors to the data source.

This commit forwards the error returned by the API and displays it in
order to help clients troubleshoot the issue.

v0.0.45

Display the time taken to update a graph by a given data source.