diff options
Diffstat (limited to 'doc/manual/src/glossary.md')
| -rw-r--r-- | doc/manual/src/glossary.md | 67 |
1 files changed, 41 insertions, 26 deletions
diff --git a/doc/manual/src/glossary.md b/doc/manual/src/glossary.md index d0aff34e2..e142bd415 100644 --- a/doc/manual/src/glossary.md +++ b/doc/manual/src/glossary.md @@ -15,7 +15,7 @@ Example: `/nix/store/g946hcz4c8mdvq2g8vxx42z51qb71rvp-git-2.38.1.drv` - See [`nix show-derivation`](./command-ref/new-cli/nix3-show-derivation.md) (experimental) for displaying the contents of store derivations. + See [`nix derivation show`](./command-ref/new-cli/nix3-derivation-show.md) (experimental) for displaying the contents of store derivations. [store derivation]: #gloss-store-derivation @@ -31,7 +31,7 @@ This means either running the `builder` executable as specified in the corresponding [derivation] or fetching a pre-built [store object] from a [substituter]. - See [`nix-build`](./command-ref/nix-build.md) and [`nix-store --realise`](./command-ref/nix-store.md#operation---realise). + See [`nix-build`](./command-ref/nix-build.md) and [`nix-store --realise`](@docroot@/command-ref/nix-store/realise.md). See [`nix build`](./command-ref/new-cli/nix3-build.md) (experimental). @@ -54,7 +54,7 @@ invoked, the Nix store can be referred to as a "_local_" or a "_remote_" one: - + A *local store* exists on the filesystem of + + A [local store]{#gloss-local-store} exists on the filesystem of the machine where Nix is invoked. You can use other local stores by passing the `--store` flag to the `nix` command. Local stores can be used for building derivations. @@ -65,17 +65,17 @@ served by the `nix-serve` Perl script. [store]: #gloss-store + [local store]: #gloss-local-store - [chroot store]{#gloss-chroot-store}\ - A local store whose canonical path is anything other than `/nix/store`. + A [local store] whose canonical path is anything other than `/nix/store`. - [binary cache]{#gloss-binary-cache}\ A *binary cache* is a Nix store which uses a different format: its metadata and signatures are kept in `.narinfo` files rather than in a - Nix database. This different format simplifies serving store objects - over the network, but cannot host builds. Examples of binary caches - include S3 buckets and the [NixOS binary - cache](https://cache.nixos.org). + [Nix database]. This different format simplifies serving store objects + over the network, but cannot host builds. Examples of binary caches + include S3 buckets and the [NixOS binary cache](https://cache.nixos.org). - [store path]{#gloss-store-path}\ The location of a [store object] in the file system, i.e., an @@ -101,14 +101,11 @@ derivation. - [output-addressed store object]{#gloss-output-addressed-store-object}\ - A store object whose store path hashes its content. This - includes derivations, the outputs of - [content-addressed derivations](#gloss-content-addressed-derivation), - and the outputs of - [fixed-output derivations](#gloss-fixed-output-derivation). + A [store object] whose [store path] is determined by its contents. + This includes derivations, the outputs of [content-addressed derivations](#gloss-content-addressed-derivation), and the outputs of [fixed-output derivations](#gloss-fixed-output-derivation). - [substitute]{#gloss-substitute}\ - A substitute is a command invocation stored in the Nix database that + A substitute is a command invocation stored in the [Nix database] that describes how to build a store object, bypassing the normal build mechanism (i.e., derivations). Typically, the substitute builds the store object by downloading a pre-built version of the store object @@ -127,6 +124,14 @@ builder can rely on external inputs such as the network or the system time) but the Nix model assumes it. + - [Nix database]{#gloss-nix-database}\ + An SQlite database to track [reference]s between [store object]s. + This is an implementation detail of the [local store]. + + Default location: `/nix/var/nix/db`. + + [Nix database]: #gloss-nix-database + - [Nix expression]{#gloss-nix-expression}\ A high-level description of software packages and compositions thereof. Deploying software using Nix entails writing Nix @@ -135,14 +140,13 @@ then be built. - [reference]{#gloss-reference}\ - A store path `P` is said to have a reference to a store path `Q` if - the store object at `P` contains the path `Q` somewhere. The - *references* of a store path are the set of store paths to which it - has a reference. + A [store object] `O` is said to have a *reference* to a store object `P` if a [store path] to `P` appears in the contents of `O`. + + Store objects can refer to both other store objects and themselves. + References from a store object to itself are called *self-references*. + References other than a self-reference must not form a cycle. - A derivation can reference other derivations and sources (but not - output paths), whereas an output path only references other output - paths. + [reference]: #gloss-reference - [reachable]{#gloss-reachable}\ A store path `Q` is reachable from another store path `P` if `Q` @@ -156,11 +160,11 @@ build-time dependencies, while the closure of its output path is equivalent to its runtime dependencies. For correct deployment it is necessary to deploy whole closures, since otherwise at runtime - files could be missing. The command `nix-store -qR` prints out + files could be missing. The command `nix-store --query --requisites ` prints out closures of store paths. - As an example, if the store object at path `P` contains a reference - to path `Q`, then `Q` is in the closure of `P`. Further, if `Q` + As an example, if the [store object] at path `P` contains a [reference] + to a store object at path `Q`, then `Q` is in the closure of `P`. Further, if `Q` references `R` then `R` is also in the closure of `P`. [closure]: #gloss-closure @@ -176,9 +180,9 @@ - [validity]{#gloss-validity}\ A store path is valid if all [store object]s in its [closure] can be read from the [store]. - For a local store, this means: + For a [local store], this means: - The store path leads to an existing [store object] in that [store]. - - The store path is listed in the Nix database as being valid. + - The store path is listed in the [Nix database] as being valid. - All paths in the store path's [closure] are valid. [validity]: #gloss-validity @@ -193,6 +197,11 @@ A symlink to the current *user environment* of a user, e.g., `/nix/var/nix/profiles/default`. + - [installable]{#gloss-installable}\ + Something that can be realised in the Nix store. + + See [installables](./command-ref/new-cli/nix.md#installables) for [`nix` commands](./command-ref/new-cli/nix.md) (experimental) for details. + - [NAR]{#gloss-nar}\ A *N*ix *AR*chive. This is a serialisation of a path in the Nix store. It can contain regular files, directories and symbolic @@ -213,3 +222,9 @@ [string]: ./language/values.md#type-string [path]: ./language/values.md#type-path [attribute name]: ./language/values.md#attribute-set + + - [experimental feature]{#gloss-experimental-feature}\ + Not yet stabilized functionality guarded by named experimental feature flags. + These flags are enabled or disabled with the [`experimental-features`](./command-ref/conf-file.html#conf-experimental-features) setting. + + See the contribution guide on the [purpose and lifecycle of experimental feaures](@docroot@/contributing/experimental-features.md). |