1 files changed, 139 insertions, 0 deletions
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_operation_stats.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_operation_stats.cpp
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+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_operation_stats.cpp
@@ -0,0 +1,139 @@
+/**
+ *    Copyright (C) 2022-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/db/storage/wiredtiger/wiredtiger_operation_stats.h"
+
+#include "mongo/bson/bsonobjbuilder.h"
+#include "mongo/db/storage/wiredtiger/wiredtiger_util.h"
+
+namespace mongo {
+namespace {
+
+enum class StatType { kData, kWait };
+
+struct StatInfo {
+    StringData name;
+    StatType type;
+};
+
+stdx::unordered_map<int, StatInfo> statInfo = {
+    {WT_STAT_SESSION_BYTES_READ, {"bytesRead"_sd, StatType::kData}},
+    {WT_STAT_SESSION_BYTES_WRITE, {"bytesWritten"_sd, StatType::kData}},
+    {WT_STAT_SESSION_LOCK_DHANDLE_WAIT, {"handleLock"_sd, StatType::kWait}},
+    {WT_STAT_SESSION_READ_TIME, {"timeReadingMicros"_sd, StatType::kData}},
+    {WT_STAT_SESSION_WRITE_TIME, {"timeWritingMicros"_sd, StatType::kData}},
+    {WT_STAT_SESSION_LOCK_SCHEMA_WAIT, {"schemaLock"_sd, StatType::kWait}},
+    {WT_STAT_SESSION_CACHE_TIME, {"cache"_sd, StatType::kWait}}};
+
+}  // namespace
+
+WiredTigerOperationStats::WiredTigerOperationStats(WT_SESSION* session) {
+    invariant(session);
+
+    WT_CURSOR* c;
+    uassert(ErrorCodes::CursorNotFound,
+            "Unable to open statistics cursor",
+            !session->open_cursor(session, "statistics:session", nullptr, "statistics=(fast)", &c));
+
+    ScopeGuard guard{[c] { c->close(c); }};
+
+    int32_t key;
+    uint64_t value;
+    while (c->next(c) == 0 && c->get_key(c, &key) == 0) {
+        fassert(51035, c->get_value(c, nullptr, nullptr, &value) == 0);
+        _stats[key] = WiredTigerUtil::castStatisticsValue<long long>(value);
+    }
+
+    // Reset the statistics so that the next fetch gives the recent values.
+    invariantWTOK(c->reset(c), c->session);
+}
+
+BSONObj WiredTigerOperationStats::toBSON() const {
+    boost::optional<BSONObjBuilder> dataSection;
+    boost::optional<BSONObjBuilder> waitSection;
+
+    for (auto&& [stat, value] : _stats) {
+        if (value == 0) {
+            continue;
+        }
+
+        auto it = statInfo.find(stat);
+        if (it == statInfo.end()) {
+            continue;
+        }
+        auto&& [name, type] = it->second;
+
+        auto appendToSection = [name = name,
+                                value = value](boost::optional<BSONObjBuilder>& section) {
+            if (!section) {
+                section.emplace();
+            }
+            section->append(name, value);
+        };
+
+        switch (type) {
+            case StatType::kData:
+                appendToSection(dataSection);
+                break;
+            case StatType::kWait:
+                appendToSection(waitSection);
+                break;
+        }
+    }
+
+    BSONObjBuilder builder;
+    if (dataSection) {
+        builder.append("data", dataSection->obj());
+    }
+    if (waitSection) {
+        builder.append("timeWaitingMicros", waitSection->obj());
+    }
+
+    return builder.obj();
+}
+
+std::shared_ptr<StorageStats> WiredTigerOperationStats::clone() const {
+    auto copy = std::make_shared<WiredTigerOperationStats>();
+    *copy += *this;
+    return copy;
+}
+
+WiredTigerOperationStats& WiredTigerOperationStats::operator+=(
+    const WiredTigerOperationStats& other) {
+    for (auto&& [stat, value] : other._stats) {
+        _stats[stat] += value;
+    }
+    return *this;
+}
+
+StorageStats& WiredTigerOperationStats::operator+=(const StorageStats& other) {
+    return *this += checked_cast<const WiredTigerOperationStats&>(other);
+}
+
+}  // namespace mongo