1 /*
2  * Copyright (c) Facebook, Inc. and its affiliates.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <fb303/ExportedStatMap.h>
18 #include <fb303/TimeseriesExporter.h>
19 
20 using folly::StringPiece;
21 
22 namespace facebook {
23 namespace fb303 {
24 
exportStat(StringPiece name,ExportType type,const ExportedStat * copyMe)25 void ExportedStatMap::exportStat(
26     StringPiece name,
27     ExportType type,
28     const ExportedStat* copyMe) {
29   StatPtr item = getStatPtrNoExport(name, nullptr, copyMe);
30   TimeseriesExporter::exportStat(item, type, name, dynamicCounters_);
31 }
32 
getStatPtr(StringPiece name,const ExportType * exportType)33 ExportedStatMap::StatPtr ExportedStatMap::getStatPtr(
34     StringPiece name,
35     const ExportType* exportType) {
36   // find the stat
37   bool created = false;
38   StatPtr item = getStatPtrNoExport(name, &created);
39 
40   if (created) {
41     // if newly created, add export types
42     if (nullptr != exportType) {
43       TimeseriesExporter::exportStat(item, *exportType, name, dynamicCounters_);
44     } else {
45       for (auto type : defaultTypes_) {
46         TimeseriesExporter::exportStat(item, type, name, dynamicCounters_);
47       }
48     }
49   }
50   return item;
51 }
52 
getStatPtrNoExport(StringPiece name,bool * createdPtr,const ExportedStat * copyMe)53 ExportedStatMap::StatPtr ExportedStatMap::getStatPtrNoExport(
54     StringPiece name,
55     bool* createdPtr,
56     const ExportedStat* copyMe) {
57   if (createdPtr) {
58     *createdPtr = false;
59   }
60 
61   {
62     auto rlock = statMap_.rlock();
63     auto iter = rlock->find(name);
64     if (iter != rlock->end()) {
65       return iter->second;
66     }
67   }
68 
69   auto ulock = statMap_.ulock();
70   auto iter = ulock->find(name);
71   if (iter != ulock->end()) {
72     // Stat was populated before we acquired the ulock.
73     return iter->second;
74   }
75 
76   auto value = std::make_shared<SyncStat>(defaultStat_);
77   if (copyMe) {
78     *value = *copyMe;
79   }
80 
81   if (createdPtr) {
82     *createdPtr = true;
83   }
84 
85   auto wlock = ulock.moveFromUpgradeToWrite();
86   auto item = wlock->try_emplace(name, std::move(value));
87   DCHECK(item.second);
88   return item.first->second;
89 }
90 
unExportStatAll(StringPiece name)91 void ExportedStatMap::unExportStatAll(StringPiece name) {
92   // Get unlocked item as we will not access the value of the item
93   // And the function called on the value assume that they can access
94   // the value without locking
95   auto lockedStatMap = statMap_.wlock();
96   auto stat = lockedStatMap->find(name);
97   if (stat != lockedStatMap->end()) {
98     for (auto type : ExportTypeMeta::kExportTypes) {
99       TimeseriesExporter::unExportStat(
100           stat->second, type, name, dynamicCounters_);
101     }
102     lockedStatMap->erase(name);
103   }
104 }
105 
forgetAllStats()106 void ExportedStatMap::forgetAllStats() {
107   statMap_.wlock()->clear();
108 }
109 
forgetStatsFor(StringPiece name)110 void ExportedStatMap::forgetStatsFor(StringPiece name) {
111   statMap_.wlock()->erase(name);
112 }
113 
clearAllStats()114 void ExportedStatMap::clearAllStats() {
115   auto lockedStatMap = statMap_.wlock();
116   for (auto& statPtrKvp : *lockedStatMap) {
117     statPtrKvp.second->lock()->clear();
118   }
119 }
120 } // namespace fb303
121 } // namespace facebook
122