SERVER-54470 Use IDL to parse $collStats

18 files changed, 266 insertions, 96 deletions

diff --git a/jstests/aggregation/sources/collStats/count.js b/jstests/aggregation/sources/collStats/count.js
index 334f42766e4..7b6117c1b94 100644
--- a/jstests/aggregation/sources/collStats/count.js
+++ b/jstests/aggregation/sources/collStats/count.js
@@ -21,9 +21,13 @@ assertErrorCode(coll, pipeline, 40602);
 
 // Test that an error is returned if count is not an object.
 pipeline = [{$collStats: {count: 1}}];
-assertErrorCode(coll, pipeline, 40480, "count spec must be an object");
+assertErrorCode(coll, pipeline, ErrorCodes.TypeMismatch, "count spec must be an object");
 pipeline = [{$collStats: {count: "1"}}];
-assertErrorCode(coll, pipeline, 40480, "count spec must be an object");
+assertErrorCode(coll, pipeline, ErrorCodes.TypeMismatch, "count spec must be an object");
+
+// Test that an error is returned if count is not an empty object.
+pipeline = [{$collStats: {count: {unrecognized: 1}}}];
+assertErrorCode(coll, pipeline, 31170, "count spec must be an empty object");
 
 // Test the accuracy of the record count as a standalone option.
 pipeline = [{$collStats: {count: {}}}];
diff --git a/jstests/aggregation/sources/collStats/query_exec_stats.js b/jstests/aggregation/sources/collStats/query_exec_stats.js
index a5b5ee687de..7e4495befe6 100644
--- a/jstests/aggregation/sources/collStats/query_exec_stats.js
+++ b/jstests/aggregation/sources/collStats/query_exec_stats.js
@@ -27,9 +27,9 @@ for (let i = 0; i < nDocs; i++) {
 
 // Test that an error is returned if queryExecStats is not an object.
 let pipeline = [{$collStats: {queryExecStats: 1}}];
-assertErrorCode(coll, pipeline, 31141, "queryExecStats spec must be an object");
+assertErrorCode(coll, pipeline, ErrorCodes.TypeMismatch, "queryExecStats spec must be an object");
 pipeline = [{$collStats: {queryExecStats: "1"}}];
-assertErrorCode(coll, pipeline, 31141, "queryExecStats spec must be an object");
+assertErrorCode(coll, pipeline, ErrorCodes.TypeMismatch, "queryExecStats spec must be an object");
 
 // Test the accuracy of the result of queryExecStats as a standalone option.
 pipeline = [{$collStats: {queryExecStats: {}}}];
diff --git a/src/mongo/db/commands/dbcommands.cpp b/src/mongo/db/commands/dbcommands.cpp
index 0a8923e5097..85c1d0b5e01 100644
--- a/src/mongo/db/commands/dbcommands.cpp
+++ b/src/mongo/db/commands/dbcommands.cpp
@@ -75,6 +75,7 @@
 #include "mongo/db/op_observer.h"
 #include "mongo/db/ops/insert.h"
 #include "mongo/db/pipeline/document_source_internal_unpack_bucket.h"
+#include "mongo/db/pipeline/storage_stats_spec_gen.h"
 #include "mongo/db/query/collation/collator_factory_interface.h"
 #include "mongo/db/query/get_executor.h"
 #include "mongo/db/query/internal_plans.h"
@@ -513,7 +514,8 @@ public:
         }
 
         result.append("ns", nss.ns());
-        Status status = appendCollectionStorageStats(opCtx, nss, jsobj, &result);
+        auto spec = StorageStatsSpec::parse(IDLParserErrorContext("collStats"), jsobj);
+        Status status = appendCollectionStorageStats(opCtx, nss, spec, &result);
         if (!status.isOK() && status.code() != ErrorCodes::NamespaceNotFound) {
             errmsg = status.reason();
             return false;
diff --git a/src/mongo/db/pipeline/SConscript b/src/mongo/db/pipeline/SConscript
index fd8e7f036ec..b73c1e533d5 100644
--- a/src/mongo/db/pipeline/SConscript
+++ b/src/mongo/db/pipeline/SConscript
@@ -329,16 +329,19 @@ env.Library(
     target='document_sources_idl',
     source=[
         'document_source_change_stream.idl',
+        'document_source_coll_stats.idl',
         'document_source_list_sessions.idl',
         'document_source_merge.idl',
         'document_source_merge_modes.idl',
+        'document_source_merge_spec.cpp',
+        'document_source_parsing_validators.cpp',
         'document_source_replace_root.idl',
         'document_source_set_window_fields.idl',
         'document_source_union_with.idl',
         'exchange_spec.idl',
+        'resume_token.cpp',
+        'storage_stats_spec.idl',
         'value.idl',
-        'document_source_merge_spec.cpp',
-        'resume_token.cpp'
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
diff --git a/src/mongo/db/pipeline/document_source_coll_stats.cpp b/src/mongo/db/pipeline/document_source_coll_stats.cpp
index 30b7255e1ce..84f57642004 100644
--- a/src/mongo/db/pipeline/document_source_coll_stats.cpp
+++ b/src/mongo/db/pipeline/document_source_coll_stats.cpp
@@ -55,48 +55,10 @@ intrusive_ptr<DocumentSource> DocumentSourceCollStats::createFromBson(
     uassert(40166,
             str::stream() << "$collStats must take a nested object but found: " << specElem,
             specElem.type() == BSONType::Object);
-    intrusive_ptr<DocumentSourceCollStats> collStats(new DocumentSourceCollStats(pExpCtx));
-
-    for (const auto& elem : specElem.embeddedObject()) {
-        StringData fieldName = elem.fieldNameStringData();
-
-        if ("latencyStats" == fieldName) {
-            uassert(40167,
-                    str::stream() << "latencyStats argument must be an object, but got " << elem
-                                  << " of type " << typeName(elem.type()),
-                    elem.type() == BSONType::Object);
-            if (!elem["histograms"].eoo()) {
-                uassert(40305,
-                        str::stream() << "histograms option to latencyStats must be bool, got "
-                                      << elem << "of type " << typeName(elem.type()),
-                        elem["histograms"].isBoolean());
-            }
-        } else if ("storageStats" == fieldName) {
-            uassert(40279,
-                    str::stream() << "storageStats argument must be an object, but got " << elem
-                                  << " of type " << typeName(elem.type()),
-                    elem.type() == BSONType::Object);
-        } else if ("count" == fieldName) {
-            uassert(40480,
-                    str::stream() << "count argument must be an object, but got " << elem
-                                  << " of type " << typeName(elem.type()),
-                    elem.type() == BSONType::Object);
-        } else if ("queryExecStats" == fieldName) {
-            uassert(31141,
-                    str::stream() << "queryExecStats argument must be an empty object, but got "
-                                  << elem << " of type " << typeName(elem.type()),
-                    elem.type() == BSONType::Object);
-            uassert(31170,
-                    str::stream() << "queryExecStats argument must be an empty object, but got "
-                                  << elem,
-                    elem.embeddedObject().isEmpty());
-        } else {
-            uasserted(40168, str::stream() << "unrecognized option to $collStats: " << fieldName);
-        }
-    }
+    auto spec = DocumentSourceCollStatsSpec::parse(IDLParserErrorContext(kStageName),
+                                                   specElem.embeddedObject());
 
-    collStats->_collStatsSpec = specElem.Obj().getOwned();
-    return collStats;
+    return make_intrusive<DocumentSourceCollStats>(pExpCtx, std::move(spec));
 }
 
 DocumentSource::GetNextResult DocumentSourceCollStats::doGetNext() {
@@ -119,33 +81,27 @@ DocumentSource::GetNextResult DocumentSourceCollStats::doGetNext() {
     builder.append("host", getHostNameCachedAndPort());
     builder.appendDate("localTime", jsTime());
 
-    if (_collStatsSpec.hasField("latencyStats")) {
-        // If the latencyStats field exists, it must have been validated as an object when parsing.
-        bool includeHistograms = false;
-        if (_collStatsSpec["latencyStats"].type() == BSONType::Object) {
-            includeHistograms = _collStatsSpec["latencyStats"]["histograms"].boolean();
-        }
+    if (auto latencyStatsSpec = _collStatsSpec.getLatencyStats()) {
         pExpCtx->mongoProcessInterface->appendLatencyStats(
-            pExpCtx->opCtx, pExpCtx->ns, includeHistograms, &builder);
+            pExpCtx->opCtx, pExpCtx->ns, latencyStatsSpec->getHistograms(), &builder);
     }
 
-    if (_collStatsSpec.hasField("storageStats")) {
+    if (auto storageStats = _collStatsSpec.getStorageStats()) {
         // If the storageStats field exists, it must have been validated as an object when parsing.
         BSONObjBuilder storageBuilder(builder.subobjStart("storageStats"));
-        uassertStatusOKWithContext(
-            pExpCtx->mongoProcessInterface->appendStorageStats(
-                pExpCtx->opCtx, pExpCtx->ns, _collStatsSpec["storageStats"].Obj(), &storageBuilder),
-            "Unable to retrieve storageStats in $collStats stage");
+        uassertStatusOKWithContext(pExpCtx->mongoProcessInterface->appendStorageStats(
+                                       pExpCtx->opCtx, pExpCtx->ns, *storageStats, &storageBuilder),
+                                   "Unable to retrieve storageStats in $collStats stage");
         storageBuilder.doneFast();
     }
 
-    if (_collStatsSpec.hasField("count")) {
+    if (_collStatsSpec.getCount()) {
         uassertStatusOKWithContext(pExpCtx->mongoProcessInterface->appendRecordCount(
                                        pExpCtx->opCtx, pExpCtx->ns, &builder),
                                    "Unable to retrieve count in $collStats stage");
     }
 
-    if (_collStatsSpec.hasField("queryExecStats")) {
+    if (_collStatsSpec.getQueryExecStats()) {
         uassertStatusOKWithContext(pExpCtx->mongoProcessInterface->appendQueryExecStats(
                                        pExpCtx->opCtx, pExpCtx->ns, &builder),
                                    "Unable to retrieve queryExecStats in $collStats stage");
@@ -155,7 +111,7 @@ DocumentSource::GetNextResult DocumentSourceCollStats::doGetNext() {
 }
 
 Value DocumentSourceCollStats::serialize(boost::optional<ExplainOptions::Verbosity> explain) const {
-    return Value(Document{{getSourceName(), _collStatsSpec}});
+    return Value(Document{{getSourceName(), _collStatsSpec.toBSON()}});
 }
 
-}  // namespace mongo
+}  // namespace mongo
\ No newline at end of file
diff --git a/src/mongo/db/pipeline/document_source_coll_stats.h b/src/mongo/db/pipeline/document_source_coll_stats.h
index 4d0be020523..bc701e14c44 100644
--- a/src/mongo/db/pipeline/document_source_coll_stats.h
+++ b/src/mongo/db/pipeline/document_source_coll_stats.h
@@ -30,6 +30,7 @@
 #pragma once
 
 #include "mongo/db/pipeline/document_source.h"
+#include "mongo/db/pipeline/document_source_coll_stats_gen.h"
 
 namespace mongo {
 
@@ -44,15 +45,21 @@ public:
     class LiteParsed final : public LiteParsedDocumentSource {
     public:
         static std::unique_ptr<LiteParsed> parse(const NamespaceString& nss,
-                                                 const BSONElement& spec) {
-            bool hasCount = spec.isABSONObj() && spec.embeddedObject().hasField("count");
-            return std::make_unique<LiteParsed>(spec.fieldName(), nss, hasCount);
+                                                 const BSONElement& specElem) {
+            uassert(5447000,
+                    str::stream() << "$collStats must take a nested object but found: " << specElem,
+                    specElem.type() == BSONType::Object);
+            auto spec = DocumentSourceCollStatsSpec::parse(IDLParserErrorContext(kStageName),
+                                                           specElem.embeddedObject());
+            return std::make_unique<LiteParsed>(specElem.fieldName(), nss, std::move(spec));
         }
 
-        explicit LiteParsed(std::string parseTimeName, NamespaceString nss, bool hasCount)
+        explicit LiteParsed(std::string parseTimeName,
+                            NamespaceString nss,
+                            DocumentSourceCollStatsSpec spec)
             : LiteParsedDocumentSource(std::move(parseTimeName)),
               _nss(std::move(nss)),
-              _hasCount(hasCount) {}
+              _spec(std::move(spec)) {}
 
         bool isCollStats() const final {
             return true;
@@ -72,16 +79,17 @@ public:
         }
 
         bool isCollStatsWithCount() const final {
-            return _hasCount;
+            return static_cast<bool>(_spec.getCount());
         }
 
     private:
         const NamespaceString _nss;
-        const bool _hasCount;
+        const DocumentSourceCollStatsSpec _spec;
     };
 
-    DocumentSourceCollStats(const boost::intrusive_ptr<ExpressionContext>& pExpCtx)
-        : DocumentSource(kStageName, pExpCtx) {}
+    DocumentSourceCollStats(const boost::intrusive_ptr<ExpressionContext>& pExpCtx,
+                            DocumentSourceCollStatsSpec spec)
+        : DocumentSource(kStageName, pExpCtx), _collStatsSpec(std::move(spec)) {}
 
     const char* getSourceName() const final;
 
@@ -112,7 +120,7 @@ private:
     GetNextResult doGetNext() final;
 
     // The raw object given to $collStats containing user specified options.
-    BSONObj _collStatsSpec;
+    DocumentSourceCollStatsSpec _collStatsSpec;
     bool _finished = false;
 };
 
diff --git a/src/mongo/db/pipeline/document_source_coll_stats.idl b/src/mongo/db/pipeline/document_source_coll_stats.idl
new file mode 100644
index 00000000000..89576b7ed00
--- /dev/null
+++ b/src/mongo/db/pipeline/document_source_coll_stats.idl
@@ -0,0 +1,69 @@
+# Copyright (C) 2021-present MongoDB, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the Server Side Public License, version 1,
+# as published by MongoDB, Inc.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# Server Side Public License for more details.
+#
+# You should have received a copy of the Server Side Public License
+# along with this program. If not, see
+# <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the Server Side Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+#
+
+global:
+  cpp_namespace: "mongo"
+  cpp_includes:
+    - "mongo/db/pipeline/document_source_parsing_validators.h"
+
+imports:
+  - "mongo/idl/basic_types.idl"
+  - "mongo/db/pipeline/storage_stats_spec.idl"
+
+structs:
+  LatencyStatsSpec:
+    description: Represents the 'latencyStats' argument to the $collStats stage.
+    strict: true
+    fields: 
+      histograms:
+        description: Adds latency histogram information to the embedded documents in latencyStats if true.
+        type: optionalBool
+  DocumentSourceCollStatsSpec:
+    description: Specification for a $collStats stage.
+    strict: true
+    fields:
+      latencyStats:
+        description: A request to include latency stats in the $collStats output.
+        type: LatencyStatsSpec
+        optional: true
+      storageStats:
+        description: Adds storage statistics to the return document.
+        type: StorageStatsSpec
+        optional: true
+      count:
+        description: Adds the total number of documents in the collection to the return document.
+        type: object
+        validator:
+          callback: validateObjectIsEmpty
+        optional: true
+      queryExecStats:
+        description: Adds query execution statistics to the return document.
+        type: object
+        validator:
+            callback: validateObjectIsEmpty
+        optional: true
\ No newline at end of file
diff --git a/src/mongo/db/pipeline/document_source_parsing_validators.cpp b/src/mongo/db/pipeline/document_source_parsing_validators.cpp
new file mode 100644
index 00000000000..f6a929ba36e
--- /dev/null
+++ b/src/mongo/db/pipeline/document_source_parsing_validators.cpp
@@ -0,0 +1,46 @@
+/**
+ *    Copyright (C) 2021-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/pipeline/document_source_parsing_validators.h"
+#include "mongo/util/str.h"
+
+namespace mongo {
+
+Status validateObjectIsEmpty(const BSONObj& object) {
+    if (!object.isEmpty()) {
+        return {
+            ErrorCodes::Error{31170},
+            str::stream() << "expected an empty object, but got " << object,
+        };
+    }
+    return Status::OK();
+}
+}  // namespace mongo
\ No newline at end of file
diff --git a/src/mongo/db/pipeline/document_source_parsing_validators.h b/src/mongo/db/pipeline/document_source_parsing_validators.h
new file mode 100644
index 00000000000..ea0c1b1e1f3
--- /dev/null
+++ b/src/mongo/db/pipeline/document_source_parsing_validators.h
@@ -0,0 +1,38 @@
+/**
+ *    Copyright (C) 2021-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/base/status.h"
+#include "mongo/bson/bsonobj.h"
+
+namespace mongo {
+Status validateObjectIsEmpty(const BSONObj&);
+
+}  // namespace mongo
\ No newline at end of file
diff --git a/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.cpp b/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.cpp
index e38da1240ea..e4a5a266954 100644
--- a/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.cpp
+++ b/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.cpp
@@ -219,9 +219,9 @@ void CommonMongodProcessInterface::appendLatencyStats(OperationContext* opCtx,
 
 Status CommonMongodProcessInterface::appendStorageStats(OperationContext* opCtx,
                                                         const NamespaceString& nss,
-                                                        const BSONObj& param,
+                                                        const StorageStatsSpec& spec,
                                                         BSONObjBuilder* builder) const {
-    return appendCollectionStorageStats(opCtx, nss, param, builder);
+    return appendCollectionStorageStats(opCtx, nss, spec, builder);
 }
 
 Status CommonMongodProcessInterface::appendRecordCount(OperationContext* opCtx,
diff --git a/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.h b/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.h
index d8e542a859c..4706c259864 100644
--- a/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.h
+++ b/src/mongo/db/pipeline/process_interface/common_mongod_process_interface.h
@@ -63,7 +63,7 @@ public:
                             BSONObjBuilder* builder) const final;
     Status appendStorageStats(OperationContext* opCtx,
                               const NamespaceString& nss,
-                              const BSONObj& param,
+                              const StorageStatsSpec& spec,
                               BSONObjBuilder* builder) const final;
     Status appendRecordCount(OperationContext* opCtx,
                              const NamespaceString& nss,
diff --git a/src/mongo/db/pipeline/process_interface/mongo_process_interface.h b/src/mongo/db/pipeline/process_interface/mongo_process_interface.h
index b88031f0277..379aa55230a 100644
--- a/src/mongo/db/pipeline/process_interface/mongo_process_interface.h
+++ b/src/mongo/db/pipeline/process_interface/mongo_process_interface.h
@@ -46,6 +46,7 @@
 #include "mongo/db/ops/write_ops_exec.h"
 #include "mongo/db/pipeline/field_path.h"
 #include "mongo/db/pipeline/lite_parsed_document_source.h"
+#include "mongo/db/pipeline/storage_stats_spec_gen.h"
 #include "mongo/db/query/explain_options.h"
 #include "mongo/db/repl/oplog_entry.h"
 #include "mongo/db/resource_yielder.h"
@@ -198,7 +199,7 @@ public:
      */
     virtual Status appendStorageStats(OperationContext* opCtx,
                                       const NamespaceString& nss,
-                                      const BSONObj& param,
+                                      const StorageStatsSpec& spec,
                                       BSONObjBuilder* builder) const = 0;
 
     /**
diff --git a/src/mongo/db/pipeline/process_interface/mongos_process_interface.h b/src/mongo/db/pipeline/process_interface/mongos_process_interface.h
index 6439d6e54fe..f34021c38d6 100644
--- a/src/mongo/db/pipeline/process_interface/mongos_process_interface.h
+++ b/src/mongo/db/pipeline/process_interface/mongos_process_interface.h
@@ -103,7 +103,7 @@ public:
 
     Status appendStorageStats(OperationContext* opCtx,
                               const NamespaceString& nss,
-                              const BSONObj& param,
+                              const StorageStatsSpec& spec,
                               BSONObjBuilder* builder) const final {
         MONGO_UNREACHABLE;
     }
diff --git a/src/mongo/db/pipeline/process_interface/stub_mongo_process_interface.h b/src/mongo/db/pipeline/process_interface/stub_mongo_process_interface.h
index 243ca833061..5afb3a85135 100644
--- a/src/mongo/db/pipeline/process_interface/stub_mongo_process_interface.h
+++ b/src/mongo/db/pipeline/process_interface/stub_mongo_process_interface.h
@@ -99,7 +99,7 @@ public:
 
     Status appendStorageStats(OperationContext* opCtx,
                               const NamespaceString& nss,
-                              const BSONObj& param,
+                              const StorageStatsSpec& spec,
                               BSONObjBuilder* builder) const override {
         MONGO_UNREACHABLE;
     }
diff --git a/src/mongo/db/pipeline/storage_stats_spec.idl b/src/mongo/db/pipeline/storage_stats_spec.idl
new file mode 100644
index 00000000000..74c6775673c
--- /dev/null
+++ b/src/mongo/db/pipeline/storage_stats_spec.idl
@@ -0,0 +1,50 @@
+# Copyright (C) 2021-present MongoDB, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the Server Side Public License, version 1,
+# as published by MongoDB, Inc.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# Server Side Public License for more details.
+#
+# You should have received a copy of the Server Side Public License
+# along with this program. If not, see
+# <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the Server Side Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+#
+
+global:
+  cpp_namespace: "mongo"
+
+imports:
+  - "mongo/idl/basic_types.idl"
+
+structs:
+  StorageStatsSpec:
+    description: Represents the 'storageStats' argument to the $collStats stage.
+    strict: false
+    fields:
+      scale:
+        description: A number to use as a scaling factor applied to reported metrics.
+        type: safeInt
+        optional: true
+        validator: { gte: 1 }
+      verbose:
+        type: optionalBool
+        default: false
+      waitForLock:
+        type: optionalBool
+        default: true
diff --git a/src/mongo/db/stats/SConscript b/src/mongo/db/stats/SConscript
index 86aa08006f2..81d74eb5a06 100644
--- a/src/mongo/db/stats/SConscript
+++ b/src/mongo/db/stats/SConscript
@@ -120,7 +120,7 @@ env.Library(
     source=[
         "latency_server_status_section.cpp",
         "lock_server_status_section.cpp",
-        'storage_stats.cpp',
+        "storage_stats.cpp",
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
@@ -132,6 +132,7 @@ env.Library(
     LIBDEPS_PRIVATE=[
         '$BUILD_DIR/mongo/db/catalog/database_holder',
         '$BUILD_DIR/mongo/db/commands/server_status',
+        '$BUILD_DIR/mongo/db/pipeline/document_sources_idl',
         '$BUILD_DIR/mongo/db/timeseries/bucket_catalog',
     ],
 )
diff --git a/src/mongo/db/stats/storage_stats.cpp b/src/mongo/db/stats/storage_stats.cpp
index 0cb59121b71..e7517e9cfbe 100644
--- a/src/mongo/db/stats/storage_stats.cpp
+++ b/src/mongo/db/stats/storage_stats.cpp
@@ -47,20 +47,11 @@ namespace mongo {
 
 Status appendCollectionStorageStats(OperationContext* opCtx,
                                     const NamespaceString& nss,
-                                    const BSONObj& param,
+                                    const StorageStatsSpec& storageStatsSpec,
                                     BSONObjBuilder* result) {
-    int scale = 1;
-    if (param["scale"].isNumber()) {
-        scale = param["scale"].numberInt();
-        if (scale < 1) {
-            return {ErrorCodes::BadValue, "scale has to be >= 1"};
-        }
-    } else if (param["scale"].trueValue()) {
-        return {ErrorCodes::BadValue, "scale has to be a number >= 1"};
-    }
-
-    bool verbose = param["verbose"].trueValue();
-    bool waitForLock = !param.hasField("waitForLock") || param["waitForLock"].trueValue();
+    auto scale = storageStatsSpec.getScale().value_or(1);
+    bool verbose = storageStatsSpec.getVerbose();
+    bool waitForLock = storageStatsSpec.getWaitForLock();
 
     bool isTimeseries = false;
     if (auto viewCatalog = DatabaseHolder::get(opCtx)->getViewCatalog(opCtx, nss.db())) {
diff --git a/src/mongo/db/stats/storage_stats.h b/src/mongo/db/stats/storage_stats.h
index 377210bb765..b2a5e3fee0f 100644
--- a/src/mongo/db/stats/storage_stats.h
+++ b/src/mongo/db/stats/storage_stats.h
@@ -34,6 +34,7 @@
 #include "mongo/bson/bsonobjbuilder.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/operation_context.h"
+#include "mongo/db/pipeline/storage_stats_spec_gen.h"
 
 namespace mongo {
 
@@ -43,14 +44,14 @@ namespace mongo {
  * Params:
  * opCtx
  * nss Fully qualified namespace.
- * param Uses "scale" (default = 1) and "verbose".
+ * spec Includes options such as "scale" (default = 1) and "verbose".
  * builder out; object the stats will be appended to.
  *
  * returns Status, (note "NamespaceNotFound" will fill result with 0-ed stats)
  */
 Status appendCollectionStorageStats(OperationContext* opCtx,
                                     const NamespaceString& nss,
-                                    const BSONObj& param,
+                                    const StorageStatsSpec& spec,
                                     BSONObjBuilder* builder);
 
 /**