Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/src/rocksdb/utilities/transactions/transaction_util.h b/src/rocksdb/utilities/transactions/transaction_util.h
new file mode 100644
index 000000000..2e48f84a4
--- /dev/null
+++ b/src/rocksdb/utilities/transactions/transaction_util.h
@@ -0,0 +1,103 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#ifndef ROCKSDB_LITE
+
+#include <string>
+#include <unordered_map>
+
+#include "db/dbformat.h"
+#include "db/read_callback.h"
+
+#include "rocksdb/db.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/status.h"
+#include "rocksdb/types.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+struct TransactionKeyMapInfo {
+  // Earliest sequence number that is relevant to this transaction for this key
+  SequenceNumber seq;
+
+  uint32_t num_writes;
+  uint32_t num_reads;
+
+  bool exclusive;
+
+  explicit TransactionKeyMapInfo(SequenceNumber seq_no)
+      : seq(seq_no), num_writes(0), num_reads(0), exclusive(false) {}
+
+  // Used in PopSavePoint to collapse two savepoints together.
+  void Merge(const TransactionKeyMapInfo& info) {
+    assert(seq <= info.seq);
+    num_reads += info.num_reads;
+    num_writes += info.num_writes;
+    exclusive |= info.exclusive;
+  }
+};
+
+using TransactionKeyMap =
+    std::unordered_map<uint32_t,
+                       std::unordered_map<std::string, TransactionKeyMapInfo>>;
+
+class DBImpl;
+struct SuperVersion;
+class WriteBatchWithIndex;
+
+class TransactionUtil {
+ public:
+  // Verifies there have been no commits to this key in the db since this
+  // sequence number.
+  //
+  // If cache_only is true, then this function will not attempt to read any
+  // SST files.  This will make it more likely this function will
+  // return an error if it is unable to determine if there are any conflicts.
+  //
+  // See comment of CheckKey() for explanation of `snap_seq`, `snap_checker`
+  // and `min_uncommitted`.
+  //
+  // Returns OK on success, BUSY if there is a conflicting write, or other error
+  // status for any unexpected errors.
+  static Status CheckKeyForConflicts(
+      DBImpl* db_impl, ColumnFamilyHandle* column_family,
+      const std::string& key, SequenceNumber snap_seq, bool cache_only,
+      ReadCallback* snap_checker = nullptr,
+      SequenceNumber min_uncommitted = kMaxSequenceNumber);
+
+  // For each key,SequenceNumber pair in the TransactionKeyMap, this function
+  // will verify there have been no writes to the key in the db since that
+  // sequence number.
+  //
+  // Returns OK on success, BUSY if there is a conflicting write, or other error
+  // status for any unexpected errors.
+  //
+  // REQUIRED: this function should only be called on the write thread or if the
+  // mutex is held.
+  static Status CheckKeysForConflicts(DBImpl* db_impl,
+                                      const TransactionKeyMap& keys,
+                                      bool cache_only);
+
+ private:
+  // If `snap_checker` == nullptr, writes are always commited in sequence number
+  // order. All sequence number <= `snap_seq` will not conflict with any
+  // write, and all keys > `snap_seq` of `key` will trigger conflict.
+  // If `snap_checker` != nullptr, writes may not commit in sequence number
+  // order. In this case `min_uncommitted` is a lower bound.
+  //  seq < `min_uncommitted`: no conflict
+  //  seq > `snap_seq`: applicable to conflict
+  //  `min_uncommitted` <= seq <= `snap_seq`: call `snap_checker` to determine.
+  static Status CheckKey(DBImpl* db_impl, SuperVersion* sv,
+                         SequenceNumber earliest_seq, SequenceNumber snap_seq,
+                         const std::string& key, bool cache_only,
+                         ReadCallback* snap_checker = nullptr,
+                         SequenceNumber min_uncommitted = kMaxSequenceNumber);
+};
+
+}  // namespace ROCKSDB_NAMESPACE
+
+#endif  // ROCKSDB_LITE