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| -rw-r--r-- | doc/manual/src/architecture/architecture.md | 125 |
1 files changed, 78 insertions, 47 deletions
diff --git a/doc/manual/src/architecture/architecture.md b/doc/manual/src/architecture/architecture.md index 3a7d1d6f5..2d1b26558 100644 --- a/doc/manual/src/architecture/architecture.md +++ b/doc/manual/src/architecture/architecture.md @@ -9,18 +9,29 @@ 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 .-------------------------. | -| | commmand line interface |------. | -| '-------------------------' | | -| | | | -| calls | | -| | manages | -| V | | -| .-------------------------. | | -| | language evaluator | | | -| '-------------------------' | | + + .----------------. + | Nix expression |----------. + '----------------' | + | passed to + | | ++----------|-------------------|--------------------------------+ +| Nix | V | +| | +-------------------------+ | +| | | commmand line interface |------. | +| | +-------------------------+ | | +| | | | | +| evaluated by calls manages | +| | | | | +| | V | | +| | +--------------------+ | | +| '-------->| language evaluator | | | +| +--------------------+ | | | | | | | produces | | | | V | @@ -28,57 +39,77 @@ Nix consists of [hierarchical layers]. | | store | | | | | referenced by V builds | | | | .-------------. .------------. .--------------. | | -| | | build input |----->| build plan | ---->| build result | | | +| | | build input |----->| build plan |----->| build result | | | | | '-------------' '------------' '--------------' | | -| +-----------------------------------------------------------+ | -+---------------------------------------------------------------+ +| +-------------------------------------------------|---------+ | ++---------------------------------------------------|-----------+ + | + represented as + | + V + .---------------. + | file | + '---------------' ``` -At the top is the [command line interface](../command-ref/command-ref.md), translating from invocations of Nix executables to interactions with the underlying layers. +At the top is the [command line interface](../command-ref/command-ref.md) that drives the underlying layers. -Below that is the evaluator for the [Nix language](../language/index.md), the configuration language for Nix. -Its expressions ultimately evaluate to self-contained *build plans*, used to derive *build results* from referenced *build inputs*. +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 the Nix language are what users interact with most. +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 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. +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 is a series of *build tasks*. -Each build task has a special build input, which is used as *build instructions*. -The result of a build task can be input to another build task. +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 + ``` -+----------------------------------------------------------------------------------+ -| store - - - - - - - - - - - - - - - - - - - - - - | -| : build plan : | -| .-------------. : : | -| | build input |---instructions-. : | -| '-------------' : | : | -| : v : | -| .-------------. : .------------. : | -| | build input |--------->| build task |-instructions-. : | -| '-------------' : '------------' | : | -| : v : | -| .-------------. : .------------. : .--------------. | -| | build input |---instructions-. | build task |--->| build result | | -| '-------------' : | '------------' : '--------------' | -| : v ^ : | -| .-------------. : .------------. | : | -| | build input |--------->| build task |--------------' : | -| '-------------' : '------------' : | -| : ^ : | -| .-------------. : | : | -| | build input |----------------' : | -| '-------------' : : | -| :_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _: | -+----------------------------------------------------------------------------------+ ++--------------------------------------------------------------------+ +| 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 |---------' | +| '-------------' | +| | ++--------------------------------------------------------------------+ ``` |