chatdesk-ui/postgrest_v12.2.8/docs/explanations/architecture.rst

96 lines
2.8 KiB
ReStructuredText

Architecture
############
This page describes the architecture of PostgREST.
Bird's Eye View
===============
You can click on the components to navigate to their respective documentation.
.. container:: img-dark
.. See https://github.com/sphinx-doc/sphinx/issues/2240#issuecomment-187366626
.. raw:: html
<object width="100%" data="../_static/arch-dark.svg" type="image/svg+xml"></object>
.. container:: img-light
.. raw:: html
<object width="100%" data="../_static/arch.svg" type="image/svg+xml"></object>
Code Map
========
This section talks briefly about various important modules.
Main
----
The starting point of the program is `Main.hs <https://github.com/PostgREST/postgrest/blob/main/main/Main.hs>`_.
CLI
---
Main then calls `CLI.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/CLI.hs>`_, which is in charge of :ref:`cli`.
App
---
`App.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/App.hs>`_ is then in charge of composing the different modules.
Auth
----
`Auth.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/Auth.hs>`_ is in charge of :ref:`authn`.
Api Request
-----------
`ApiRequest.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/ApiRequest.hs>`_ is in charge of parsing the URL query string (following PostgREST syntax), the request headers, and the request body.
A request might be rejected at this level if it's invalid. For example when providing an unknown media type to PostgREST or using an unknown HTTP method.
Plan
----
Using the Schema Cache, `Plan.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/Plan.hs>`_ fills in out-of-band SQL details (like an ``ON CONFLICT (pk)`` clause) required to complete the user request.
A request might be rejected at this level if it's invalid. For example when doing resource embedding on a nonexistent resource.
Query
-----
`Query.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/Query.hs>`_ generates the SQL queries (parametrized and prepared) required to satisfy the user request.
Only at this stage a connection from the pool might be used.
Schema Cache
------------
`SchemaCache.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/SchemaCache.hs>`_ is in charge of :ref:`schema_cache`.
Config
------
`Config.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/Config.hs>`_ is in charge of :ref:`configuration`.
Admin
-----
`Admin.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/Admin.hs>`_ is in charge of the :ref:`admin_server`.
HTTP
----
The HTTP server is provided by `Warp <https://aosabook.org/en/posa/warp.html>`_.
Listener
--------
`Listener.hs <https://github.com/PostgREST/postgrest/blob/main/src/PostgREST/Listener.hs>`_ is in charge of the :ref:`listener`.