diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/manual/src/architecture/store/objects.md | 15 | ||||
| -rw-r--r-- | doc/manual/src/architecture/store/store.md | 23 |
2 files changed, 17 insertions, 21 deletions
diff --git a/doc/manual/src/architecture/store/objects.md b/doc/manual/src/architecture/store/objects.md index f7587e112..8ab0b9368 100644 --- a/doc/manual/src/architecture/store/objects.md +++ b/doc/manual/src/architecture/store/objects.md @@ -35,21 +35,6 @@ A bare file or symlink can be a root file system object. Symlinks pointing outside of their own root, or to a store object without a matching reference, are allowed, but might not function as intended. -## Reference {#reference} - -A store object can reference other store objects. - -Nix stores have the *closure property*: for each store object in the store, all the store objects it references must also be in the store. - -Building, copying and deleting store objects must be done in a way that obeys this property: - -- Build results must only refer to store objects in the closure of the build inputs. - -- Store objects being copied must refer to objects already in the destination store. - Recursive copying must either proceed in dependency order or be atomic. - -- We can only safely delete unreferenced objects. - ### Reference scanning While references could be arbitrary paths, Nix requires them to be store paths to ensure correctness. diff --git a/doc/manual/src/architecture/store/store.md b/doc/manual/src/architecture/store/store.md index 5a0f4a2df..a3d9e2eeb 100644 --- a/doc/manual/src/architecture/store/store.md +++ b/doc/manual/src/architecture/store/store.md @@ -52,15 +52,26 @@ References are [opaque][opaque-data-type], [unique identifiers][unique-identifie The only way to obtain references is by adding or building store objects. A reference will always point to exactly one store object. -An added store object cannot have references, unless it is a build task. +Nix stores have the *closure property*: for each store object in the store, all the store objects it references must also be in the store. -Building a store object will add appropriate references, according to provided build instructions. -These references can only come from declared build inputs, and are not known to build instructions a priori. +Adding, building, copying and deleting store objects must be done in a way that obeys this property: -A store object cannot be deleted as long as it is reachable from a reference still in use. -Garbage collection will delete all store objects that cannot be reached from any reference in use. +- A newly added store object cannot have references, unless it is a build task. -<!-- more details in section on garbage collection, link to it once it exists --> +- Build results must only refer to store objects in the closure of the build inputs. + + Building a store object will add appropriate references, according to provided build instructions. + These references can only come from declared build inputs. + +- Store objects being copied must refer to objects already in the destination store. + + Recursive copying must either proceed in dependency order or be atomic. + +- We can only safely delete store objects which are not reachable from any reference still in use. + + Garbage collection will delete all store objects that cannot be reached from any reference in use. + + <!-- more details in section on garbage collection, link to it once it exists --> [garbage-collection]: https://en.m.wikipedia.org/wiki/Garbage_collection_(computer_science) [immutable-object]: https://en.m.wikipedia.org/wiki/Immutable_object |