Handle errors in tenant_size_model code

libs/tenant_size_model/Cargo.toml

@@ -7,3 +7,5 @@ license = "Apache-2.0"
 
 [dependencies]
 workspace_hack = { version = "0.1", path = "../../workspace_hack" }
+log = { version = "0.4", features = ["std", "serde"] }
+anyhow = "1.0.68"

libs/tenant_size_model/src/lib.rs

@@ -1,6 +1,9 @@
 use std::borrow::Cow;
 use std::collections::HashMap;
 
+use anyhow::Context;
+use log::info;
+
 /// Pricing model or history size builder.
 ///
 /// Maintains knowledge of the branches and their modifications. Generic over the branch name key
@@ -134,7 +137,7 @@ impl<K: std::hash::Hash + Eq + 'static> Storage<K> {
         size: Option<u64>,
     ) where
         K: std::borrow::Borrow<Q>,
-        Q: std::hash::Hash + Eq,
+        Q: std::hash::Hash + Eq + std::fmt::Debug,
     {
         let lastseg_id = *self.branches.get(branch).unwrap();
         let newseg_id = self.segments.len();
@@ -214,20 +217,24 @@ impl<K: std::hash::Hash + Eq + 'static> Storage<K> {
     }
 
     /// Panics if the parent branch cannot be found.
-    pub fn branch<Q: ?Sized>(&mut self, parent: &Q, name: K)
+    pub fn branch<Q: ?Sized>(&mut self, parent: &Q, name: K) -> anyhow::Result<()>
     where
-        K: std::borrow::Borrow<Q>,
-        Q: std::hash::Hash + Eq,
+        K: std::borrow::Borrow<Q> + std::fmt::Debug,
+        Q: std::hash::Hash + Eq + std::fmt::Debug,
     {
         // Find the right segment
-        let branchseg_id = *self
-            .branches
-            .get(parent)
-            .expect("should had found the parent by key");
+        let branchseg_id = *self.branches.get(parent).with_context(|| {
+            format!(
+                "should had found the parent {:?} by key. in branches {:?}",
+                parent, self.branches
+            )
+        })?;
+
         let _branchseg = &mut self.segments[branchseg_id];
 
         // Create branch name for it
         self.branches.insert(name, branchseg_id);
+        Ok(())
     }
 
     pub fn calculate(&mut self, retention_period: u64) -> SegmentSize {

libs/tenant_size_model/src/main.rs

@@ -38,7 +38,7 @@ fn scenario_2() -> (Vec<Segment>, SegmentSize) {
     }
 
     // Branch
-    storage.branch("main", "child");
+    storage.branch("main", "child").unwrap();
     storage.update("child", 1_000);
 
     // More updates on parent
@@ -63,7 +63,7 @@ fn scenario_3() -> (Vec<Segment>, SegmentSize) {
     }
 
     // Branch
-    storage.branch("main", "child");
+    storage.branch("main", "child").unwrap();
     storage.update("child", 1_000);
 
     // More updates on parent
@@ -90,7 +90,7 @@ fn scenario_4() -> (Vec<Segment>, SegmentSize) {
     }
 
     // Branch
-    storage.branch("main", "child");
+    storage.branch("main", "child").unwrap();
     storage.update("child", 1_000);
 
     // More updates on parent
@@ -106,10 +106,10 @@ fn scenario_4() -> (Vec<Segment>, SegmentSize) {
 fn scenario_5() -> (Vec<Segment>, SegmentSize) {
     let mut storage = Storage::new("a");
     storage.insert("a", 5000);
-    storage.branch("a", "b");
+    storage.branch("a", "b").unwrap();
     storage.update("b", 4000);
     storage.update("a", 2000);
-    storage.branch("a", "c");
+    storage.branch("a", "c").unwrap();
     storage.insert("c", 4000);
     storage.insert("a", 2000);
 
@@ -133,12 +133,12 @@ fn scenario_6() -> (Vec<Segment>, SegmentSize) {
 
     let mut storage = Storage::new(None);
 
-    storage.branch(&None, branches[0]); // at 0
+    storage.branch(&None, branches[0]).unwrap(); // at 0
     storage.modify_branch(&branches[0], NO_OP, 108951064, 43696128); // at 108951064
-    storage.branch(&branches[0], branches[1]); // at 108951064
+    storage.branch(&branches[0], branches[1]).unwrap(); // at 108951064
     storage.modify_branch(&branches[1], NO_OP, 15560408, -1851392); // at 124511472
     storage.modify_branch(&branches[0], NO_OP, 174464360, -1531904); // at 283415424
-    storage.branch(&branches[0], branches[2]); // at 283415424
+    storage.branch(&branches[0], branches[2]).unwrap(); // at 283415424
     storage.modify_branch(&branches[2], NO_OP, 15906192, 8192); // at 299321616
     storage.modify_branch(&branches[0], NO_OP, 18909976, 32768); // at 302325400