Let GetOperation take in explicit database read guard

Use a `shared_ptr` to enable multiple operations to share the same
logical snapshot.

5 files changed, 19 insertions, 11 deletions

diff --git a/storage/src/tests/distributor/getoperationtest.cpp b/storage/src/tests/distributor/getoperationtest.cpp
index 7c308e152db..99d7c12551d 100644
--- a/storage/src/tests/distributor/getoperationtest.cpp
+++ b/storage/src/tests/distributor/getoperationtest.cpp
@@ -3,6 +3,8 @@
 #include <vespa/config/helper/configgetter.h>
 #include <vespa/document/config/config-documenttypes.h>
 #include <vespa/document/repo/documenttyperepo.h>
+#include <vespa/storage/bucketdb/bucketdatabase.h>
+#include <vespa/storage/distributor/distributor_bucket_space.h>
 #include <vespa/storage/distributor/externaloperationhandler.h>
 #include <vespa/storage/distributor/distributor.h>
 #include <vespa/storage/distributor/distributormetricsset.h>
@@ -31,7 +33,7 @@ struct GetOperationTest : Test, DistributorTestUtil {
     std::unique_ptr<Operation> op;
 
     GetOperationTest();
-    ~GetOperationTest();
+    ~GetOperationTest() override;
 
     void SetUp() override {
         _repo.reset(
@@ -53,6 +55,7 @@ struct GetOperationTest : Test, DistributorTestUtil {
         auto msg = std::make_shared<api::GetCommand>(makeDocumentBucket(document::BucketId(0)), docId, "[all]");
         op = std::make_unique<GetOperation>(
                 getExternalOperationHandler(), getDistributorBucketSpace(),
+                getDistributorBucketSpace().getBucketDatabase().acquire_read_guard(),
                 msg, getDistributor().getMetrics(). gets[msg->getLoadType()]);
         op->start(_sender, framework::MilliSecTime(0));
     }
diff --git a/storage/src/vespa/storage/distributor/externaloperationhandler.cpp b/storage/src/vespa/storage/distributor/externaloperationhandler.cpp
index 1b88f02cac6..f1f786d84ac 100644
--- a/storage/src/vespa/storage/distributor/externaloperationhandler.cpp
+++ b/storage/src/vespa/storage/distributor/externaloperationhandler.cpp
@@ -284,8 +284,8 @@ IMPL_MSG_COMMAND_H(ExternalOperationHandler, Get)
     document::Bucket bucket(cmd->getBucket().getBucketSpace(), getBucketId(cmd->getDocumentId()));
     auto& metrics = getMetrics().gets[cmd->getLoadType()];
     bounce_or_invoke_read_only_op(*cmd, bucket, metrics, [&](auto& bucket_space_repo) {
-        _op = std::make_shared<GetOperation>(*this, bucket_space_repo.get(cmd->getBucket().getBucketSpace()),
-                                             cmd, metrics);
+        auto& space = bucket_space_repo.get(cmd->getBucket().getBucketSpace());
+        _op = std::make_shared<GetOperation>(*this, space, space.getBucketDatabase().acquire_read_guard(), cmd, metrics);
     });
     return true;
 }
diff --git a/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp
index 6cfc688db0e..768da935fd2 100644
--- a/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp
@@ -46,6 +46,7 @@ GetOperation::GroupId::operator==(const GroupId& other) const
 
 GetOperation::GetOperation(DistributorComponent& manager,
                            DistributorBucketSpace &bucketSpace,
+                           std::shared_ptr<BucketDatabase::ReadGuard> read_guard,
                            std::shared_ptr<api::GetCommand> msg,
                            PersistenceOperationMetricSet& metric)
     : Operation(),
@@ -58,7 +59,7 @@ GetOperation::GetOperation(DistributorComponent& manager,
       _metric(metric),
       _operationTimer(manager.getClock())
 {
-    assignTargetNodeGroups();
+    assignTargetNodeGroups(*read_guard);
 }
 
 void
@@ -213,13 +214,13 @@ GetOperation::sendReply(DistributorMessageSender& sender)
 }
 
 void
-GetOperation::assignTargetNodeGroups()
+GetOperation::assignTargetNodeGroups(const BucketDatabase::ReadGuard& read_guard)
 {
     document::BucketIdFactory bucketIdFactory;
     document::BucketId bid = bucketIdFactory.getBucketId(_msg->getDocumentId());
 
     std::vector<BucketDatabase::Entry> entries;
-    _bucketSpace.getBucketDatabase().acquire_read_guard()->find_parents_and_self(bid, entries);
+    read_guard.find_parents_and_self(bid, entries);
 
     for (uint32_t j = 0; j < entries.size(); ++j) {
         const BucketDatabase::Entry& e = entries[j];
diff --git a/storage/src/vespa/storage/distributor/operations/external/getoperation.h b/storage/src/vespa/storage/distributor/operations/external/getoperation.h
index 3936f13077e..8d0fdb0c2bb 100644
--- a/storage/src/vespa/storage/distributor/operations/external/getoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/getoperation.h
@@ -3,7 +3,7 @@
 
 #include <vespa/storageapi/defs.h>
 #include <vespa/storage/distributor/operations/operation.h>
-#include <vespa/storage/bucketdb/bucketcopy.h>
+#include <vespa/storage/bucketdb/bucketdatabase.h>
 #include <vespa/storageapi/messageapi/storagemessage.h>
 #include <vespa/storageframework/generic/clock/timer.h>
 
@@ -23,8 +23,11 @@ class DistributorBucketSpace;
 class GetOperation  : public Operation
 {
 public:
-    GetOperation(DistributorComponent& manager, DistributorBucketSpace &bucketSpace,
-                 std::shared_ptr<api::GetCommand> msg, PersistenceOperationMetricSet& metric);
+    GetOperation(DistributorComponent& manager,
+                 DistributorBucketSpace &bucketSpace,
+                 std::shared_ptr<BucketDatabase::ReadGuard> read_guard,
+                 std::shared_ptr<api::GetCommand> msg,
+                 PersistenceOperationMetricSet& metric);
 
     void onClose(DistributorMessageSender& sender) override;
     void onStart(DistributorMessageSender& sender) override;
@@ -89,7 +92,7 @@ private:
     void sendReply(DistributorMessageSender& sender);
     bool sendForChecksum(DistributorMessageSender& sender, const document::BucketId& id, GroupVector& res);
 
-    void assignTargetNodeGroups();
+    void assignTargetNodeGroups(const BucketDatabase::ReadGuard& read_guard);
     bool copyIsOnLocalNode(const BucketCopy&) const;
     /**
      * Returns the vector index of the target to send to, or -1 if none
diff --git a/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp
index b7ebafc114c..b3326a43be2 100644
--- a/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp
@@ -178,7 +178,8 @@ TwoPhaseUpdateOperation::startSafePathUpdate(DistributorMessageSender& sender)
     document::Bucket bucket(_updateCmd->getBucket().getBucketSpace(), document::BucketId(0));
     auto get = std::make_shared<api::GetCommand>(bucket, _updateCmd->getDocumentId(),"[all]");
     copyMessageSettings(*_updateCmd, *get);
-    auto getOperation = std::make_shared<GetOperation>(_manager, _bucketSpace, get, _getMetric);
+    auto getOperation = std::make_shared<GetOperation>(
+            _manager, _bucketSpace, _bucketSpace.getBucketDatabase().acquire_read_guard(), get, _getMetric);
     GetOperation & op = *getOperation;
     IntermediateMessageSender intermediate(_sentMessageMap, std::move(getOperation), sender);
     op.start(intermediate, _manager.getClock().getTimeInMillis());