Add used assumptions.

LECO_ASSUMPTIONS.md

@@ -0,0 +1,74 @@
+# Assumptions of LECO
+
+LECO is not yet fully defined, but some features are required for the code to work.
+Here are internal definitions used for PyLECO, which are not yet in LECO, so they might change.
+
+The assumptions link to issues/pull requests, where these points are discussed.
+
+## Control Protocol
+
+### Control Protocol Message
+
+The header frame consists of three parts:
+1. UUIDv7 as conversation_id
+2. 3 bytes as message_id, the content (whether a timestamp or a count) is not yet defined.
+3. 1 byte as message_type which contains the serialization scheme:
+   - 0 means not defined,
+   - 1 means JSON, our default
+
+### Message content
+
+Messages use JSONRPC messages.
+Also the control messages (sign_in etc.) are done via JSONRPC.
+Error codes are also defined.
+All this is in [PR #56](https://github.com/pymeasure/leco-protocol/pull/56) defined.
+
+
+### Coordinator Workings
+
+#### Directory update at sign-in/sign-out
+
+At each sign-in/sign-out of a Component, the Coordinator sends the full directory (components/Coordinators) to all known Coordinators.
+
+If a not signed in Coordinator tries to sign out, the Coordinator ignores that message.
+
+If a Coordinator tries to sign out, but the message arrives via a different identity, the sign-out is rejected.
+
+
+## Data Protocol
+
+### Message Format
+
+A Data Protocol Message consists in three or more frames ([#62](https://github.com/pymeasure/leco-protocol/issues/62)):
+1. Topic (see below)
+2. Header (see below)
+3. One or more data frames
+
+#### Topic
+
+The topic is the full name of the sending Component. ([#60](https://github.com/pymeasure/leco-protocol/issues/60))
+
+#### Header
+
+Similar to the control protocol ([#61](https://github.com/pymeasure/leco-protocol/issues/61)):
+1. UUIDv7
+2. 1 byte Message_type (0 not defined, 1 JSON, >127 user defined)
+
+#### Content
+
+For log messages, the content is a list of:
+- record.asctime: Timestamp formatted as '%Y-%m-%d %H:%M:%S'
+- record.levelname: Logger level name
+- record.name: Logger name
+- record text (including traceback)
+
+
+## General
+
+As default ports for the different applications:
+
+- COORDINATOR_PORT = 12300  # the Coordinator receives and sends at that port.
+- PROXY_RECEIVING_PORT = 11100  # the proxy server receives at that port
+- PROXY_SENDING_PORT = 11099  # the proxy server sends at that port
+- LOG_RECEIVING_PORT = 11098  # the log server receives at that port
+- LOG_SENDING_PORT = 11097  # the log server sends at that port

README.md

@@ -8,6 +8,8 @@ The [stable-development branch](https://github.com/pymeasure/pyleco/tree/stable-
 Follow that branch to have always working code (as far as possible), but following the ongoing development.
 
 Note: LECO is still under development, such that the code and API might change.
+[LECO_ASSUMPTIONS](LECO_ASSUMPTIONS.md) contains the assumptions used in this project, which are not yet defined by LECO.
+These things might change, if LECO defines them differently
 
 ![badge](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/bmoneke/7a8a7b874b62ed803eb56ca04830bede/raw/pyleco-coverage.json)