Implement getEstimatedShrinkLidSpaceGain() for LogDataStore.

2 files changed, 3 insertions, 0 deletions

diff --git a/searchlib/src/tests/docstore/document_store/document_store_test.cpp b/searchlib/src/tests/docstore/document_store/document_store_test.cpp
index 8cb4cd8168e..b2b73b1d9ef 100644
--- a/searchlib/src/tests/docstore/document_store/document_store_test.cpp
+++ b/searchlib/src/tests/docstore/document_store/document_store_test.cpp
@@ -38,6 +38,7 @@ struct NullDataStore : IDataStore {
     }
     virtual void compactLidSpace(uint32_t wantedDocLidLimit) override { (void) wantedDocLidLimit; }
     virtual bool canShrinkLidSpace() const override { return false; }
+    virtual size_t getEstimatedShrinkLidSpaceGain() const override { return 0; }
     virtual void shrinkLidSpace() override {}
 };
 
diff --git a/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp b/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
index 761d32224f5..99259b109b2 100644
--- a/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
+++ b/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
@@ -917,10 +917,12 @@ TEST_F("require that lid space can be compacted and shrunk", Fixture)
     f.compactLidSpace(2);
     MemoryUsage before = f.store.getMemoryUsage();
     EXPECT_TRUE(f.store.canShrinkLidSpace());
+    EXPECT_EQUAL(8u, f.store.getEstimatedShrinkLidSpaceGain()); // one lid info entry
     f.store.shrinkLidSpace();
 
     MemoryUsage after = f.store.getMemoryUsage();
     EXPECT_LESS(after.usedBytes(), before.usedBytes());
+    EXPECT_EQUAL(8u, before.usedBytes() - after.usedBytes());
 }
 
 TEST_F("require that lid space can be increased after being compacted and then shrunk", Fixture)