Merge pull request #22 from earthstar-project/successors

Path Successors [✨ surprises ✨]

.gitignore

@@ -1 +1 @@
-/target
+**/target

Cargo.toml

@@ -1,4 +1,5 @@
 [workspace]
 
-members = ["data-model"]
+members = ["data-model", "fuzz"]
 resolver = "2"
+

data-model/Cargo.toml

@@ -4,4 +4,4 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-bytes = "1.4"
+arbitrary = { version = "1.0.2", features = ["derive"]}

data-model/src/entry.rs

@@ -112,7 +112,11 @@ mod tests {
 
     #[derive(Default, PartialEq, Eq, PartialOrd, Ord, Clone)]
     struct FakeSubspaceId(usize);
-    impl SubspaceId for FakeSubspaceId {}
+    impl SubspaceId for FakeSubspaceId {
+        fn successor(&self) -> Option<Self> {
+            Some(FakeSubspaceId(self.0 + 1))
+        }
+    }
 
     #[derive(Default, PartialEq, Eq, PartialOrd, Ord, Clone)]
     struct FakePayloadDigest(usize);

data-model/src/grouping/area.rs

@@ -4,7 +4,7 @@ use crate::{
     path::Path,
 };
 
-use super::{range::Range, range_3d::Range3d};
+use super::range::Range;
 
 /// The possible values of an [`Area`]'s `subspace`.
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
@@ -112,7 +112,11 @@ mod tests {
 
     #[derive(Debug, Default, PartialEq, Eq, PartialOrd, Ord, Clone)]
     struct FakeSubspaceId(usize);
-    impl SubspaceId for FakeSubspaceId {}
+    impl SubspaceId for FakeSubspaceId {
+        fn successor(&self) -> Option<Self> {
+            Some(FakeSubspaceId(self.0 + 1))
+        }
+    }
 
     #[derive(Default, PartialEq, Eq, PartialOrd, Ord, Clone)]
     struct FakePayloadDigest(usize);

data-model/src/grouping/range_3d.rs

@@ -73,7 +73,11 @@ mod tests {
 
     #[derive(Default, PartialEq, Eq, PartialOrd, Ord, Clone, Debug)]
     struct FakeSubspaceId(usize);
-    impl SubspaceId for FakeSubspaceId {}
+    impl SubspaceId for FakeSubspaceId {
+        fn successor(&self) -> Option<Self> {
+            Some(FakeSubspaceId(self.0 + 1))
+        }
+    }
 
     #[derive(Default, PartialEq, Eq, PartialOrd, Ord, Clone)]
     struct FakePayloadDigest(usize);

data-model/src/parameters.rs

@@ -11,7 +11,11 @@ pub trait NamespaceId: Eq + Default + Clone {}
 /// ## Implementation notes
 ///
 /// The [`Default`] implementation **must** return the least element in the total order of [`SubspaceId`].
-pub trait SubspaceId: Ord + Default + Clone {}
+pub trait SubspaceId: Ord + Default + Clone {
+    /// Return the next possible value in the set of all [`SubspaceId`].
+    /// e.g. the successor of 3 is 4.
+    fn successor(&self) -> Option<Self>;
+}
 
 /// A totally ordered type for [content-addressing](https://en.wikipedia.org/wiki/Content_addressing) the data that Willow stores.
 /// [Definition](https://willowprotocol.org/specs/data-model/index.html#PayloadDigest).