SERVER-22359 Rename OperationShardVersion to OperationShardingState

This name is more appropriate now, because we will be attaching more
metadata to it such as the critical section wait handle, which is
necessary for parallel migrations.

1 files changed, 125 insertions, 0 deletions

diff --git a/src/mongo/db/s/operation_sharding_state.cpp b/src/mongo/db/s/operation_sharding_state.cpp
new file mode 100644
index 00000000000..906c491aac3
--- /dev/null
+++ b/src/mongo/db/s/operation_sharding_state.cpp
@@ -0,0 +1,125 @@
+/*
+*    Copyright (C) 2015 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/s/operation_sharding_state.h"
+
+#include "mongo/db/operation_context.h"
+
+namespace mongo {
+
+namespace {
+
+const OperationContext::Decoration<OperationShardingState> shardingMetadataDecoration =
+    OperationContext::declareDecoration<OperationShardingState>();
+
+const ChunkVersion kUnshardedVersion(ChunkVersion::UNSHARDED());
+
+}  // namespace mongo
+
+OperationShardingState::OperationShardingState() = default;
+
+OperationShardingState& OperationShardingState::get(OperationContext* txn) {
+    return shardingMetadataDecoration(txn);
+}
+
+void OperationShardingState::initializeShardVersion(NamespaceString ns,
+                                                    const BSONElement& shardVersionElt) {
+    invariant(!hasShardVersion());
+
+    if (ns.isSystemDotIndexes()) {
+        setShardVersion(std::move(ns), ChunkVersion::IGNORED());
+        return;
+    }
+
+    if (shardVersionElt.eoo() || shardVersionElt.type() != BSONType::Array) {
+        return;
+    }
+
+    const BSONArray versionArr(shardVersionElt.Obj());
+    bool hasVersion = false;
+    ChunkVersion newVersion = ChunkVersion::fromBSON(versionArr, &hasVersion);
+
+    if (!hasVersion) {
+        return;
+    }
+
+    setShardVersion(std::move(ns), std::move(newVersion));
+}
+
+bool OperationShardingState::hasShardVersion() const {
+    return _hasVersion;
+}
+
+const ChunkVersion& OperationShardingState::getShardVersion(const NamespaceString& ns) const {
+    if (_ns != ns) {
+        return kUnshardedVersion;
+    }
+
+    return _shardVersion;
+}
+
+void OperationShardingState::setShardVersion(NamespaceString ns, ChunkVersion newVersion) {
+    // This currently supports only setting the shard version for one namespace.
+    invariant(!_hasVersion || _ns == ns);
+    invariant(!ns.isSystemDotIndexes() || ChunkVersion::isIgnoredVersion(newVersion));
+
+    _ns = std::move(ns);
+    _shardVersion = std::move(newVersion);
+    _hasVersion = true;
+}
+
+void OperationShardingState::_clear() {
+    _hasVersion = false;
+    _shardVersion = ChunkVersion();
+    _ns = NamespaceString();
+}
+
+OperationShardingState::IgnoreVersioningBlock::IgnoreVersioningBlock(OperationContext* txn,
+                                                                     const NamespaceString& ns)
+    : _txn(txn), _ns(ns) {
+    auto& operationVersion = OperationShardingState::get(txn);
+    _hadOriginalVersion = operationVersion._hasVersion;
+    if (_hadOriginalVersion) {
+        _originalVersion = operationVersion.getShardVersion(ns);
+    }
+    operationVersion.setShardVersion(ns, ChunkVersion::IGNORED());
+}
+
+OperationShardingState::IgnoreVersioningBlock::~IgnoreVersioningBlock() {
+    auto& operationVersion = OperationShardingState::get(_txn);
+    invariant(ChunkVersion::isIgnoredVersion(operationVersion.getShardVersion(_ns)));
+    if (_hadOriginalVersion) {
+        operationVersion.setShardVersion(_ns, _originalVersion);
+    } else {
+        operationVersion._clear();
+    }
+}
+
+}  // namespace mongo