| Application { |
| n1: circle label:"Start" |
| n2: rectangle label:"Request data by key" |
| n3: rectangle label:"Return data to caller" |
| n4: circle label:"End" |
| n1.handle(right) -> n2.handle(left) |
| n2.handle(bottom) -> CacheLayer.n5.handle(top) [label="Lookup"] |
| n3.handle(right) -> n4.handle(left) |
| } |
| CacheLayer { |
| n5: rectangle label:"Check cache for key" |
| n6: diamond label:"Cache hit?" |
| n7: rectangle label:"Return cached value" |
| n8: rectangle label:"Query database" |
| n9: rectangle label:"Store in cache with TTL" |
| n5.handle(right) -> n6.handle(left) |
| n6.handle(right) -> n7.handle(left) [label="Yes"] |
| n6.handle(bottom) -> n8.handle(top) [label="No"] |
| n7.handle(top) -> Application.n3.handle(bottom) [label="From cache"] |
| n8.handle(bottom) -> Database.n10.handle(top) [label="Fetch"] |
| n9.handle(top) -> Application.n3.handle(bottom) [label="From DB"] |
| } |
| Database { |
| n10: rectangle label:"Execute query" |
| n11: diamond label:"Data found?" |
| n12: rectangle label:"Return result set" |
| n13: rectangle label:"Return empty result" |
| n10.handle(right) -> n11.handle(left) |
| n11.handle(right) -> n12.handle(left) [label="Yes"] |
| n11.handle(bottom) -> n13.handle(top) [label="No"] |
| n12.handle(top) -> CacheLayer.n9.handle(bottom) [label="Populate cache"] |
| n13.handle(top) -> Application.n3.handle(bottom) [label="Not found"] |
| } |
| WriteOperation { |
| n14: rectangle label:"Update database" |
| n15: rectangle label:"Invalidate cache key" |
| n16: diamond label:"Write-through?" |
| n17: rectangle label:"Update cache directly" |
| n18: rectangle label:"Let cache expire" |
| n14.handle(right) -> n15.handle(left) |
| n15.handle(right) -> n16.handle(left) |
| n16.handle(right) -> n17.handle(left) [label="Yes"] |
| n16.handle(bottom) -> n18.handle(top) [label="No"] |
| n17.handle(top) -> Application.n3.handle(bottom) [label="Updated"] |
| n18.handle(top) -> Application.n3.handle(bottom) [label="Invalidated"] |
| } |
|
|
