feat(resources) add http-project-guide

2026-09-06 23:43:45 +02:00 · 2020-06-08 22:32:20 +01:00
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+---
+authors:
+  - "Kibb#4205"
+created_at: 2020/06/08
+title: "Chapter 6: What is a protocol?"
+---
+
+## Chapter 6: What is a protocol?
+How do we humans communicate? Through a mutually agreed convention of a language and conventions.
+Similarly, How do we make clients and servers talk to each other? 
+They need some sort of agreed way to ask for things and respond with replies or errors. This mutually agreed set of rules is commonly known as a protocol.
+
+In this chapter, we are going to create a really simple protocol for getting and storing strings, a *dictionary*.
+With our hypothetical protocol your server will store the definition to a series of words.
+You can do this nice and simply with a map like data structure or something more complex, your choice.
+
+In a client-server architecture, genrally a client initiates communication by making a request to the server. In our case, the client will make a request to *get* a definition from the dictionary server.
+
+To *get* a definition, the client will send this:
+```txt
+GET someword
+```
+All lines in this protocol will be terminated with `\n`
+
+Your server will then look that word up and reply with the value stored against it. 
+The server will need to reply with a sensible error message if the word does not exist.
+
+For now the reply will be either
+```txt
+ANSWER the description
+```
+or 
+```txt
+ERROR can't find someword
+```
+We have created a simple reading protocol. This protocol can be extended by adding new requests of the form:
+```txt
+VERB args go here
+```
+I encourage you to mess about and add other verb based commands.
+
+## Goals
+
+- Read `GET word` from the client
+- Reply `ANSWER definition` to the client
+- Give errors on undefined words. `ERROR undefined`
+
+## Bonus goals
+
+- Allow clients to `SET word definition*` at runtime. Where definition might be multiple words ending in `\n`
+- Add other commands like `CLEAR` to clear all definitions or `ALL` to get all words currently defined.