mirror of
https://github.com/privatevoid-net/nix-super.git
synced 2024-11-22 14:06:16 +02:00
Merge pull request #7066 from fricklerhandwerk/architecture-overview
manual: architecture overview
This commit is contained in:
Théophane Hufschmitt
GitHub
commit
a654ae8269
2 changed files with 116 additions and 0 deletions
|
|
@ -59,6 +59,7 @@
|
||||||
@manpages@
|
@manpages@
|
||||||
- [Files](command-ref/files.md)
|
- [Files](command-ref/files.md)
|
||||||
- [nix.conf](command-ref/conf-file.md)
|
- [nix.conf](command-ref/conf-file.md)
|
||||||
|
- [Architecture](architecture/architecture.md)
|
||||||
- [Glossary](glossary.md)
|
- [Glossary](glossary.md)
|
||||||
- [Contributing](contributing/contributing.md)
|
- [Contributing](contributing/contributing.md)
|
||||||
- [Hacking](contributing/hacking.md)
|
- [Hacking](contributing/hacking.md)
|
||||||
|
|
|
||||||
115
doc/manual/src/architecture/architecture.md
Normal file
115
doc/manual/src/architecture/architecture.md
Normal file
|
|
@ -0,0 +1,115 @@
|
||||||
|
# Architecture
|
||||||
|
|
||||||
|
This chapter describes how Nix works.
|
||||||
|
It should help users understand why Nix behaves as it does, and it should help developers understand how to modify Nix and how to write similar tools.
|
||||||
|
|
||||||
|
## Overview
|
||||||
|
|
||||||
|
Nix consists of [hierarchical layers].
|
||||||
|
|
||||||
|
[hierarchical layers]: https://en.m.wikipedia.org/wiki/Multitier_architecture#Layers
|
||||||
|
|
||||||
|
The following [concept map] shows its main components (rectangles), the objects they operate on (rounded rectangles), and their interactions (connecting phrases):
|
||||||
|
|
||||||
|
[concept map]: https://en.m.wikipedia.org/wiki/Concept_map
|
||||||
|
|
||||||
|
```
|
||||||
|
|
||||||
|
.----------------.
|
||||||
|
| Nix expression |----------.
|
||||||
|
'----------------' |
|
||||||
|
| passed to
|
||||||
|
| |
|
||||||
|
+----------|-------------------|--------------------------------+
|
||||||
|
| Nix | V |
|
||||||
|
| | +-------------------------+ |
|
||||||
|
| | | commmand line interface |------. |
|
||||||
|
| | +-------------------------+ | |
|
||||||
|
| | | | |
|
||||||
|
| evaluated by calls manages |
|
||||||
|
| | | | |
|
||||||
|
| | V | |
|
||||||
|
| | +--------------------+ | |
|
||||||
|
| '-------->| language evaluator | | |
|
||||||
|
| +--------------------+ | |
|
||||||
|
| | | |
|
||||||
|
| produces | |
|
||||||
|
| | V |
|
||||||
|
| +----------------------------|------------------------------+ |
|
||||||
|
| | store | | |
|
||||||
|
| | referenced by V builds | |
|
||||||
|
| | .-------------. .------------. .--------------. | |
|
||||||
|
| | | build input |----->| build plan |----->| build result | | |
|
||||||
|
| | '-------------' '------------' '--------------' | |
|
||||||
|
| +-------------------------------------------------|---------+ |
|
||||||
|
+---------------------------------------------------|-----------+
|
||||||
|
|
|
||||||
|
represented as
|
||||||
|
|
|
||||||
|
V
|
||||||
|
.---------------.
|
||||||
|
| file |
|
||||||
|
'---------------'
|
||||||
|
```
|
||||||
|
|
||||||
|
At the top is the [command line interface](../command-ref/command-ref.md) that drives the underlying layers.
|
||||||
|
|
||||||
|
The [Nix language](../language/index.md) evaluator transforms Nix expressions into self-contained *build plans*, which are used to derive *build results* from referenced *build inputs*.
|
||||||
|
|
||||||
|
The command line interface and Nix expressions are what users deal with most.
|
||||||
|
|
||||||
|
> **Note**
|
||||||
|
> The Nix language itself does not have a notion of *packages* or *configurations*.
|
||||||
|
> As far as we are concerned here, the inputs and results of a build plan are just data.
|
||||||
|
|
||||||
|
Underlying the command line interface and the Nix language evaluator is the [Nix store](../glossary.md#gloss-store), a mechanism to keep track of build plans, data, and references between them.
|
||||||
|
It can also execute build plans to produce new data, which are made available to the operating system as files.
|
||||||
|
|
||||||
|
A build plan itself is a series of *build tasks*, together with their build inputs.
|
||||||
|
|
||||||
|
> **Important**
|
||||||
|
> A build task in Nix is called [derivation](../glossary#gloss-derivation).
|
||||||
|
|
||||||
|
Each build task has a special build input executed as *build instructions* in order to perform the build.
|
||||||
|
The result of a build task can be input to another build task.
|
||||||
|
|
||||||
|
The following [data flow diagram] shows a build plan for illustration.
|
||||||
|
Build inputs used as instructions to a build task are marked accordingly:
|
||||||
|
|
||||||
|
[data flow diagram]: https://en.m.wikipedia.org/wiki/Data-flow_diagram
|
||||||
|
|
||||||
|
```
|
||||||
|
+--------------------------------------------------------------------+
|
||||||
|
| build plan |
|
||||||
|
| |
|
||||||
|
| .-------------. |
|
||||||
|
| | build input |---------. |
|
||||||
|
| '-------------' | |
|
||||||
|
| instructions |
|
||||||
|
| | |
|
||||||
|
| v |
|
||||||
|
| .-------------. .----------. |
|
||||||
|
| | build input |-->( build task )-------. |
|
||||||
|
| '-------------' '----------' | |
|
||||||
|
| instructions |
|
||||||
|
| | |
|
||||||
|
| v |
|
||||||
|
| .-------------. .----------. .--------------. |
|
||||||
|
| | build input |---------. ( build task )--->| build result | |
|
||||||
|
| '-------------' | '----------' '--------------' |
|
||||||
|
| instructions ^ |
|
||||||
|
| | | |
|
||||||
|
| v | |
|
||||||
|
| .-------------. .----------. | |
|
||||||
|
| | build input |-->( build task )-------' |
|
||||||
|
| '-------------' '----------' |
|
||||||
|
| ^ |
|
||||||
|
| | |
|
||||||
|
| | |
|
||||||
|
| .-------------. | |
|
||||||
|
| | build input |---------' |
|
||||||
|
| '-------------' |
|
||||||
|
| |
|
||||||
|
+--------------------------------------------------------------------+
|
||||||
|
```
|
||||||
|
|
||||||
Loading…
Reference in a new issue