SERVER-46533 Persist underlying BSON in CmdUpdate invocation

(cherry picked from commit 270bd8cb3def190b7a46b02a65cbbedacbed7a9c)

4 files changed, 68 insertions, 50 deletions

diff --git a/jstests/noPassthrough/mirror_reads.js b/jstests/noPassthrough/mirror_reads.js
index 3f897912dab..1a31a775c55 100644
--- a/jstests/noPassthrough/mirror_reads.js
+++ b/jstests/noPassthrough/mirror_reads.js
@@ -147,6 +147,10 @@ function verifyMirrorReads(rst, cmd) {
     jsTestLog("Verifying mirrored reads for 'findAndModify' commands");
     verifyMirrorReads(rst, {findAndModify: kCollName, query: {}, update: {'$inc': {x: 1}}});
 
+    jsTestLog("Verifying mirrored reads for 'update' commands");
+    verifyMirrorReads(
+        rst, {update: kCollName, updates: [{q: {_id: 1}, u: {'$inc': {x: 1}}}], ordered: false});
+
     rst.stopSet();
 }
 
diff --git a/src/mongo/db/commands/SConscript b/src/mongo/db/commands/SConscript
index 3673aa5db9b..1d4d971be89 100644
--- a/src/mongo/db/commands/SConscript
+++ b/src/mongo/db/commands/SConscript
@@ -572,22 +572,20 @@ env.CppUnitTest(
     ],
 )
 
-# TODO SERVER-46533 Reenable this test when update can participate in read mirroring again
-if False:
-    env.CppUnitTest(
-        target="command_mirroring_test",
-        source=[
-            'command_mirroring_test.cpp',
-        ],
-        LIBDEPS=[
-            '$BUILD_DIR/mongo/base',
-            '$BUILD_DIR/mongo/db/auth/authorization_manager_global',
-            '$BUILD_DIR/mongo/db/auth/authmocks',
-            '$BUILD_DIR/mongo/db/commands/standalone',
-            '$BUILD_DIR/mongo/db/service_context',
-            '$BUILD_DIR/mongo/unittest/unittest',
-        ],
-    )
+env.CppUnitTest(
+    target="command_mirroring_test",
+    source=[
+        'command_mirroring_test.cpp',
+    ],
+    LIBDEPS=[
+        '$BUILD_DIR/mongo/base',
+        '$BUILD_DIR/mongo/db/auth/authorization_manager_global',
+        '$BUILD_DIR/mongo/db/auth/authmocks',
+        '$BUILD_DIR/mongo/db/commands/standalone',
+        '$BUILD_DIR/mongo/db/service_context',
+        '$BUILD_DIR/mongo/unittest/unittest',
+    ],
+)
 
 env.CppUnitTest(
     target="db_commands_test",
diff --git a/src/mongo/db/commands/command_mirroring_test.cpp b/src/mongo/db/commands/command_mirroring_test.cpp
index e9677a77b9d..3f7f2753a5b 100644
--- a/src/mongo/db/commands/command_mirroring_test.cpp
+++ b/src/mongo/db/commands/command_mirroring_test.cpp
@@ -54,14 +54,13 @@ public:
         client.reset(nullptr);
     }
 
-    virtual BSONObj makeCommand(std::string, std::vector<BSONObj>) = 0;
+    virtual OpMsgRequest makeCommand(std::string, std::vector<BSONObj>) = 0;
 
     const LogicalSessionId& getLogicalSessionId() const {
         return _lsid;
     }
 
-    BSONObj getMirroredCommand(BSONObj& bson) {
-        auto request = OpMsgRequest::fromDBAndBody(kDB, bson);
+    BSONObj getMirroredCommand(OpMsgRequest& request) {
         auto cmd = globalCommandRegistry()->findCommand(request.getCommandName());
         ASSERT(cmd);
 
@@ -84,18 +83,23 @@ private:
 
 class UpdateCommandTest : public CommandMirroringTest {
 public:
-    BSONObj makeCommand(std::string coll, std::vector<BSONObj> updates) override {
+    OpMsgRequest makeCommand(std::string coll, std::vector<BSONObj> updates) override {
         BSONObjBuilder bob;
 
         bob << "update" << coll;
-        BSONArrayBuilder bab;
+        bob << "lsid" << getLogicalSessionId().toBSON();
+
+        auto request = OpMsgRequest::fromDBAndBody(kDB, bob.obj());
+
+        // Directly add `updates` to `OpMsg::sequences` to emulate `OpMsg::parse()` behavior.
+        OpMsg::DocumentSequence seq;
+        seq.name = "updates";
         for (auto update : updates) {
-            bab << update;
+            seq.objs.emplace_back(std::move(update));
         }
-        bob << "updates" << bab.arr();
-        bob << "lsid" << getLogicalSessionId().toBSON();
+        request.sequences.emplace_back(std::move(seq));
 
-        return bob.obj();
+        return request;
     }
 };
 
diff --git a/src/mongo/db/commands/write_commands/write_commands.cpp b/src/mongo/db/commands/write_commands/write_commands.cpp
index 93d0b8650e0..8241c5e3de6 100644
--- a/src/mongo/db/commands/write_commands/write_commands.cpp
+++ b/src/mongo/db/commands/write_commands/write_commands.cpp
@@ -334,40 +334,47 @@ private:
                    UpdateMetrics* updateMetrics)
             : InvocationBase(cmd, request),
               _batch(UpdateOp::parse(request)),
-              _updateMetrics{updateMetrics} {
+              _updateMetrics{updateMetrics},
+              _commandObj(request.body) {
             invariant(_updateMetrics);
+            invariant(_commandObj.isOwned());
+
+            // Extend the lifetime of `updates` to allow asynchronous mirroring.
+            if (auto seq = request.getSequence("updates"_sd); seq && !seq->objs.empty()) {
+                // Current design ignores contents of `updates` array except for the first entry.
+                // Assuming identical collation for all elements in `updates`, future design could
+                // use the disjunction primitive (i.e, `$or`) to compile all queries into a single
+                // filter. Such a design also requires a sound way of combining hints.
+                invariant(seq->objs.front().isOwned());
+                _updateOpObj = seq->objs.front();
+            }
         }
 
         bool supportsReadMirroring() const override {
-            // TODO SERVER-46533 Remove this and uncomment below when update can be safely mirrored.
-            // Disable readMIrrroing for update
-            return false;
-
-            // This would translate to a find command with no filter!
-            // Based on the documentation for `update`, this vector should never be empty.
-            // return !_batch.getUpdates().empty();
+            return true;
         }
 
         void appendMirrorableRequest(BSONObjBuilder* bob) const override {
-            auto extractQueryDetails = [](const write_ops::Update& query,
-                                          BSONObjBuilder* bob) -> void {
-                auto updates = query.getUpdates();
-                // `supportsReadMirroring()` is responsible for this validation.
-                invariant(!updates.empty());
-
-                // Current design ignores contents of `updates` array except for the first entry.
-                // Assuming identical collation for all elements in `updates`, future design could
-                // use the disjunction primitive (i.e, `$or`) to compile all queries into a single
-                // filter. Such a design also requires a sound way of combining hints.
-                bob->append("filter", updates.front().getQ());
-                if (!updates.front().getHint().isEmpty())
-                    bob->append("hint", updates.front().getHint());
-                if (updates.front().getCollation())
-                    bob->append("collation", *updates.front().getCollation());
+            auto extractQueryDetails = [](const BSONObj& update, BSONObjBuilder* bob) -> void {
+                // "filter", "hint", and "collation" fields are optional.
+                if (update.isEmpty())
+                    return;
+
+                // The constructor verifies the following.
+                invariant(update.isOwned());
+
+                if (update.hasField("q"))
+                    bob->append("filter", update["q"].Obj());
+                if (update.hasField("hint") && !update["hint"].Obj().isEmpty())
+                    bob->append("hint", update["hint"].Obj());
+                if (update.hasField("collation") && !update["collation"].Obj().isEmpty())
+                    bob->append("collation", update["collation"].Obj());
             };
 
-            bob->append("find", _batch.getNamespace().coll());
-            extractQueryDetails(_batch, bob);
+            invariant(!_commandObj.isEmpty());
+
+            bob->append("find", _commandObj["update"].String());
+            extractQueryDetails(_updateOpObj, bob);
             bob->append("batchSize", 1);
             bob->append("singleBatch", true);
         }
@@ -452,6 +459,11 @@ private:
 
         // Update related command execution metrics.
         UpdateMetrics* const _updateMetrics;
+
+        BSONObj _commandObj;
+
+        // Holds a shared pointer to the first entry in `updates` array.
+        BSONObj _updateOpObj;
     };
 
     std::unique_ptr<CommandInvocation> parse(OperationContext*, const OpMsgRequest& request) {