From ee2dc9969fd46d710b7d17c297f3768f57a40e57 Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Tue, 18 Dec 2018 00:13:50 +0300 Subject: big picture --- ARCHITECTURE.md | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'ARCHITECTURE.md') diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md index d31290483..3b200bbc8 100644 --- a/ARCHITECTURE.md +++ b/ARCHITECTURE.md @@ -4,6 +4,33 @@ This document describes high-level architecture of rust-analyzer. If you want to familiarize yourself with the code base, you are just in the right place! +## The Big Picture + +![](https://user-images.githubusercontent.com/1711539/50114578-e8a34280-0255-11e9-902c-7cfc70747966.png) + +On the highest level, rust-analyzer is a thing which accepts input source code +from the client and produces a structured semantic model of the code. + +More specifically, input data consists of a set of test files (`(PathBuf, +String)` pairs) and an information about project structure, the so called +`CrateGraph`. Crate graph specifies which files are crate roots, which cfg flags +are specified for each crate (TODO: actually implement this) and what are +dependencies between the crate. The analyzer keeps all these input data in +memory and never does any IO. Because the input data is source code, which +typically measures in tens of megabytes at most, keeping all input data in +memory is OK. + +A "structured semantic model" is basically an object-oriented representations of +modules, functions and types which appear in the source code. This representation +is fully "resolved": all expressions have types, all references are bound to +declarations, etc. + +The client can submit a small delta of input data (typically, a change to a +single file) and get a fresh code model which accounts for changes. + +Underlying engine makes sure that model is computed lazily (on-demand) and can +be quickly updated for small modifications. + ## Code generation @@ -86,7 +113,7 @@ current state, incorporates changes and handles out `Analysis` --- an immutable consistent snapshot of world state at a point in time, which actually powers analysis. -One interesting aspect of analysis is its support for cancelation. When a change +One interesting aspect of analysis is its support for cancellation. When a change is applied to `AnalysisHost`, first all currently active snapshots are cancelled. Only after all snapshots are dropped the change actually affects the database. -- cgit v1.2.3