storaged: Don't duplicate uid_records from proto files.

It is possible for storaged to load the same saved proto file multiple
times, for example, if system_server crashes. In this case we do not
want to fill io_history with duplicate entries. This patch elides
records for which an app+userid record already exists for the same
timestamp.

Bug: 111578975
Test: gtest storaged_test.load_uid_io_proto
Change-Id: I87bc3e37d6464079cece03b5852285d79067b935
Merged-In: I87bc3e37d6464079cece03b5852285d79067b935

storaged/include/storaged_uid_monitor.h

@@ -79,6 +79,8 @@ struct uid_records {
 class uid_monitor {
 private:
     FRIEND_TEST(storaged_test, uid_monitor);
+    FRIEND_TEST(storaged_test, load_uid_io_proto);
+
     // last dump from /proc/uid_io/stats, uid -> uid_info
     unordered_map<uint32_t, uid_info> last_uid_io_stats_;
     // current io usage for next report, app name -> uid_io_usage
@@ -118,7 +120,7 @@ public:
     bool enabled() { return enabled_; };
     void report(unordered_map<int, StoragedProto>* protos);
     // restores io_history from protobuf
-    void load_uid_io_proto(const UidIOUsage& proto);
+    void load_uid_io_proto(userid_t user_id, const UidIOUsage& proto);
     void clear_user_history(userid_t user_id);
 
     map<uint64_t, uid_records>& io_history() { return io_history_; }

storaged/storaged.cpp

@@ -194,7 +194,7 @@ void storaged_t::load_proto(userid_t user_id) {
         return;
     }
 
-    mUidm.load_uid_io_proto(proto.uid_io_usage());
+    mUidm.load_uid_io_proto(user_id, proto.uid_io_usage());
 
     if (user_id == USER_SYSTEM) {
         storage_info->load_perf_history_proto(proto.perf_history());

storaged/storaged_uid_monitor.cpp

@@ -21,6 +21,7 @@
 
 #include <string>
 #include <unordered_map>
+#include <unordered_set>
 
 #include <android/content/pm/IPackageManagerNative.h>
 #include <android-base/file.h>
@@ -468,7 +469,7 @@ void uid_monitor::clear_user_history(userid_t user_id)
     }
 }
 
-void uid_monitor::load_uid_io_proto(const UidIOUsage& uid_io_proto)
+void uid_monitor::load_uid_io_proto(userid_t user_id, const UidIOUsage& uid_io_proto)
 {
     if (!enabled()) return;
 
@@ -478,8 +479,23 @@ void uid_monitor::load_uid_io_proto(const UidIOUsage& uid_io_proto)
         const UidIORecords& records_proto = item_proto.records();
         struct uid_records* recs = &io_history_[item_proto.end_ts()];
 
+        // It's possible that the same uid_io_proto file gets loaded more than
+        // once, for example, if system_server crashes. In this case we avoid
+        // adding duplicate entries, so we build a quick way to check for
+        // duplicates.
+        std::unordered_set<std::string> existing_uids;
+        for (const auto& rec : recs->entries) {
+            if (rec.ios.user_id == user_id) {
+                existing_uids.emplace(rec.name);
+            }
+        }
+
         recs->start_ts = records_proto.start_ts();
         for (const auto& rec_proto : records_proto.entries()) {
+            if (existing_uids.find(rec_proto.uid_name()) != existing_uids.end()) {
+                continue;
+            }
+
             struct uid_record record;
             record.name = rec_proto.uid_name();
             record.ios.user_id = rec_proto.user_id();

storaged/tests/storaged_test.cpp

@@ -551,8 +551,8 @@ TEST(storaged_test, uid_monitor) {
         },
     };
 
-    uidm.load_uid_io_proto(protos[0].uid_io_usage());
-    uidm.load_uid_io_proto(protos[1].uid_io_usage());
+    uidm.load_uid_io_proto(0, protos[0].uid_io_usage());
+    uidm.load_uid_io_proto(1, protos[1].uid_io_usage());
 
     EXPECT_EQ(io_history.size(), 3UL);
     EXPECT_EQ(io_history.count(200), 1UL);
@@ -627,3 +627,40 @@ TEST(storaged_test, uid_monitor) {
 
     EXPECT_EQ(uidm.io_history_.size(), 0UL);
 }
+
+TEST(storaged_test, load_uid_io_proto) {
+    uid_monitor uidm;
+
+    uidm.io_history_[200] = {
+        .start_ts = 100,
+        .entries = {
+            { "app1", {
+                .user_id = 0,
+                .uid_ios.bytes[WRITE][FOREGROUND][CHARGER_ON] = 1000,
+              }
+            },
+            { "app2", {
+                .user_id = 0,
+                .uid_ios.bytes[READ][FOREGROUND][CHARGER_OFF] = 2000,
+              }
+            },
+            { "app3", {
+                .user_id = 0,
+                .uid_ios.bytes[READ][FOREGROUND][CHARGER_OFF] = 3000,
+              }
+            },
+        },
+    };
+
+    unordered_map<int, StoragedProto> protos;
+    uidm.update_uid_io_proto(&protos);
+    ASSERT_EQ(protos.size(), size_t(1));
+
+    // Loading the same proto many times should not add duplicate entries.
+    const UidIOUsage& user_0 = protos[0].uid_io_usage();
+    for (size_t i = 0; i < 10000; i++) {
+        uidm.load_uid_io_proto(0, user_0);
+    }
+    ASSERT_EQ(uidm.io_history_.size(), size_t(1));
+    ASSERT_EQ(uidm.io_history_[200].entries.size(), size_t(3));
+}