SERVER-34179 refactor isGenericArgument

    Remove the static tables floating around at namespace scope.

    break CommandHelpers::isGenericArgument into
    command_generic_argument library so it doesn't have to be inline.
    Some callers depend on it but would have a circularity if they
    actually added db/commands to their LIBDEPS.

1 files changed, 106 insertions, 0 deletions

diff --git a/src/mongo/db/command_generic_argument.cpp b/src/mongo/db/command_generic_argument.cpp
new file mode 100644
index 00000000000..ef9530d1cb0
--- /dev/null
+++ b/src/mongo/db/command_generic_argument.cpp
@@ -0,0 +1,106 @@
+/**
+ *    Copyright (C) 2018 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    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
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    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 GNU Affero General 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/command_generic_argument.h"
+
+#include <algorithm>
+#include <array>
+#include <cstdlib>
+#include <iterator>
+
+namespace mongo {
+
+namespace {
+
+struct SpecialArgRecord {
+    StringData name;
+    bool isGeneric : 1;
+    bool stripFromRequest : 1;
+    bool stripFromReply : 1;
+};
+
+// Not including "help" since we don't pass help requests through to the command parser.
+// If that changes, it should be added. When you add to this list, consider whether you
+// should also change the filterCommandRequestForPassthrough() function.
+// clang-format off
+static constexpr std::array<SpecialArgRecord, 23> specials{{
+    //                                       /-isGeneric
+    //                                       |  /-stripFromRequest
+    //                                       |  |  /-stripFromReply
+    {"$audit"_sd,                            1, 1, 0},
+    {"$client"_sd,                           1, 1, 0},
+    {"$configServerState"_sd,                1, 1, 1},
+    {"$db"_sd,                               1, 1, 0},
+    {"allowImplicitCollectionCreation"_sd,   1, 1, 0},
+    {"$oplogQueryData"_sd,                   1, 1, 1},
+    {"$queryOptions"_sd,                     1, 0, 0},
+    {"$readPreference"_sd,                   1, 1, 0},
+    {"$replData"_sd,                         1, 1, 1},
+    {"$clusterTime"_sd,                      1, 1, 1},
+    {"maxTimeMS"_sd,                         1, 0, 0},
+    {"readConcern"_sd,                       1, 0, 0},
+    {"databaseVersion"_sd,                   1, 1, 0},
+    {"shardVersion"_sd,                      1, 1, 0},
+    {"tracking_info"_sd,                     1, 1, 0},
+    {"writeConcern"_sd,                      1, 0, 0},
+    {"lsid"_sd,                              1, 0, 0},
+    {"txnNumber"_sd,                         1, 0, 0},
+    {"autocommit"_sd,                        1, 1, 0},
+    {"stmtId"_sd,                            1, 0, 0},
+    {"$gleStats"_sd,                         0, 0, 1},
+    {"operationTime"_sd,                     0, 0, 1},
+    {"lastCommittedOpTime"_sd,               0, 0, 1}}};
+// clang-format on
+
+const SpecialArgRecord* findSpecialArg(StringData arg) {
+    for (const auto& e : specials)
+        if (e.name == arg)
+            return &e;
+    return nullptr;
+}
+
+}  // namespace
+
+bool isGenericArgument(StringData arg) {
+    auto p = findSpecialArg(arg);
+    return p && p->isGeneric;
+}
+
+bool isRequestStripArgument(StringData arg) {
+    auto p = findSpecialArg(arg);
+    return p && p->stripFromRequest;
+}
+
+bool isReplyStripArgument(StringData arg) {
+    auto p = findSpecialArg(arg);
+    return p && p->stripFromReply;
+}
+
+}  // namespace mongo