12708: TODO notes about memory use and class combinations.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tclegg@veritasgenetics.com>

diff --git a/services/keep-balance/block_state.go b/services/keep-balance/block_state.go
index 6fd50f477989acc94485205336a30977c96b56ca..22e89c019ab9fa5a5fb833bf84bbc63df7a4e93b 100644 (file)
--- a/services/keep-balance/block_state.go
+++ b/services/keep-balance/block_state.go
@@ -25,6 +25,14 @@ type Replica struct {
 type BlockState struct {
        Replicas []Replica
        Desired  map[string]int
+       // TODO: Support combinations of classes ("private + durable")
+       // by replacing the map[string]int with a map[*[]string]int
+       // here, where the map keys come from a pool of semantically
+       // distinct class combinations.
+       //
+       // TODO: Use a pool of semantically distinct Desired maps to
+       // conserve memory (typically there are far more BlockState
+       // objects in memory than distinct Desired profiles).
 }
 
 var defaultClasses = []string{"default"}