* add types to represent unparsed http gql requests
This will help when we add caching of frequently used ASTs
* query plan caching
* move livequery to execute
* add multiplexed module
* session variable can be customised depending on the context
Previously the value was always "current_setting('hasura.user')"
* get rid of typemap requirement in reusable plan
* subscriptions are multiplexed when possible
* use lazytx for introspection to avoid acquiring a pg connection
* refactor to make execute a completely decoupled module
* don't issue a transaction for a query
* don't use current setting for explained sql
* move postgres related types to a different module
* validate variableValues on postgres before multiplexing subs
* don't user current_setting for queries over ws
* plan_cache is only visible when developer flag is enabled
* introduce 'batch size' when multiplexing subscriptions
* bump stackage to 13.16
* fix schema_stitching test case error code
* store hashes instead of actual responses for subscriptions
* internal api to dump subscriptions state
* remove PlanCache from SchemaCacheRef
* allow live query options to be configured on server startup
* capture metrics for multiplexed subscriptions
* more metrics captured for multiplexed subs
* switch to tvar based hashmap for faster snapshotting
* livequery modules do not expose internal details
* fix typo in live query env vars
* switch to hasura's pg-client-hs
* read version from env var at build time (close#1398)
* remove un-used imports, edit makefile
* edit makefile to add new targets and export variables
* only export VERSION in makefile
* read version by executing the script if env var is absent
From `alpha-40` we've been using a `WHERE` clause to fetch required rows and generate mutation response. This has a few limitations like the requirement of a primary key/unique constraint. This also returns inconsistent data on `delete` mutation as mentioned in #1794.
Now, we're using `VALUES (..)` (refer [here](https://www.postgresql.org/docs/current/sql-values.html)) expression to form virtual table rows in `SQL` to generate mutation response.
Internal changes:-
- Not to use primary key/unique constraint columns:-
- Revert back to `ConstraintName` from `TableConstraint` in `TableInfo` type
- Remove `tcCols` field in `TableConstraint` type
- Modify `table_info.sql` and `fetchTableMeta` function `SQL`
- A test case to perform `delete` mutation and returning relational objects.
1. Haskel library `pg-client-hs` has been updated to expose a function that helps listen to `postgres` notifications over a `channel` in this [PR](https://github.com/hasura/pg-client-hs/pull/5)
2. The server records an event in a table `hdb_catalog.hdb_cache_update_event` whenever any `/v1/query` (that changes metadata) is requested. A trigger notifies a `cache update` event via `hasura_cache_update` channel
3. The server runs two concurrent threads namely `listener` and `processor`. The `listener` thread listens to events on `hasura_cache_update` channel and pushed into a `Queue`. The `processor` thread fetches events from that `Queue` and processes it. Thus server rebuilds schema cache from database and updates.
If returning field contains nested selections then mutation is performed in two steps
1. Mutation is performed with returning columns of any primary key and unique constraints
2. returning fields are queried on rows returned by selecting from table by filtering with column values returned in Step 1.
Since mutation takes two courses based on selecting relations in returning field, it is hard to maintain sequence of prepared arguments (PrepArg) generated while resolving returning field. So, we're using txtConverter instead of prepare to resolve mutation fields.
* read cookie while initialising websocket connection (fix#1660)
* add tests for cookie on websocket init
* fix logic for tests
* enforce cors, and flag to force read cookie when cors disabled
- as browsers don't enforce SOP on websockets, we enforce CORS policy
on websocket handshake
- if CORS is disabled, by default cookie is not read (because XSS
risk!). Add special flag to force override this behaviour
* add log and forward origin header to webhook
- add log notice when cors is disabled, and cookie is not read on
websocket handshake
- forward origin header to webhook in POST mode. So that when CORS is
disabled, webhook can also enforce CORS independently.
* add docs, and forward all client headers to webhook
Rename the admin secret key header used to access GraphQL engine from X-Hasura-Access-Key to X-Hasura-Admin-Secret.
Server CLI and console all support the older flag but marks it as deprecated.
* support jsonb and geometry operators on RQL bool exps, close#1408
* add tests for jsonb operators in /v1/query
TODO:-
-> add tests for geometry (postgis) operators
* support parsing session variables for st_d_within and has_key ops
-> Add tests for boolExp operators and select permissions
* improve parsing $st_d_within op's json value logic
