// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // Use trace_analyzer::Query and trace_analyzer::TraceAnalyzer to search for // specific trace events that were generated by the trace_event.h API. // // Basic procedure: // - Get trace events JSON string from base::trace_event::TraceLog. // - Create TraceAnalyzer with JSON string. // - Call TraceAnalyzer::AssociateBeginEndEvents (optional). // - Call TraceAnalyzer::AssociateEvents (zero or more times). // - Call TraceAnalyzer::FindEvents with queries to find specific events. // // A Query is a boolean expression tree that evaluates to true or false for a // given trace event. Queries can be combined into a tree using boolean, // arithmetic and comparison operators that refer to data of an individual trace // event. // // The events are returned as trace_analyzer::TraceEvent objects. // TraceEvent contains a single trace event's data, as well as a pointer to // a related trace event. The related trace event is typically the matching end // of a begin event or the matching begin of an end event. // // The following examples use this basic setup code to construct TraceAnalyzer // with the json trace string retrieved from TraceLog and construct an event // vector for retrieving events: // // TraceAnalyzer analyzer(json_events); // TraceEventVector events; // // EXAMPLE 1: Find events named "my_event". // // analyzer.FindEvents(Query(EVENT_NAME) == "my_event", &events); // // EXAMPLE 2: Find begin events named "my_event" with duration > 1 second. // // Query q = (Query(EVENT_NAME) == Query::String("my_event") && // Query(EVENT_PHASE) == Query::Phase(TRACE_EVENT_PHASE_BEGIN) && // Query(EVENT_DURATION) > Query::Double(1000000.0)); // analyzer.FindEvents(q, &events); // // EXAMPLE 3: Associating event pairs across threads. // // If the test needs to analyze something that starts and ends on different // threads, the test needs to use INSTANT events. The typical procedure is to // specify the same unique ID as a TRACE_EVENT argument on both the start and // finish INSTANT events. Then use the following procedure to associate those // events. // // Step 1: instrument code with custom begin/end trace events. // [Thread 1 tracing code] // TRACE_EVENT_INSTANT1("test_latency", "timing1_begin", "id", 3); // [Thread 2 tracing code] // TRACE_EVENT_INSTANT1("test_latency", "timing1_end", "id", 3); // // Step 2: associate these custom begin/end pairs. // Query begin(Query(EVENT_NAME) == Query::String("timing1_begin")); // Query end(Query(EVENT_NAME) == Query::String("timing1_end")); // Query match(Query(EVENT_ARG, "id") == Query(OTHER_ARG, "id")); // analyzer.AssociateEvents(begin, end, match); // // Step 3: search for "timing1_begin" events with existing other event. // Query q = (Query(EVENT_NAME) == Query::String("timing1_begin") && // Query(EVENT_HAS_OTHER)); // analyzer.FindEvents(q, &events); // // Step 4: analyze events, such as checking durations. // for (size_t i = 0; i < events.size(); ++i) { // double duration; // EXPECT_TRUE(events[i].GetAbsTimeToOtherEvent(&duration)); // EXPECT_LT(duration, 1000000.0/60.0); // expect less than 1/60 second. // } // // There are two helper functions, Start(category_filter_string) and Stop(), for // facilitating the collection of process-local traces and building a // TraceAnalyzer from them. A typical test, that uses the helper functions, // looks like the following: // // TEST_F(...) { // Start("*"); // [Invoke the functions you want to test their traces] // auto analyzer = Stop(); // // [Use the analyzer to verify produced traces, as explained above] // } // // Note: The Stop() function needs a SingleThreadTaskRunner. #ifndef BASE_TEST_TRACE_EVENT_ANALYZER_H_ #define BASE_TEST_TRACE_EVENT_ANALYZER_H_ #include #include #include #include #include #include #include "base/memory/raw_ptr.h" #include "base/memory/ref_counted.h" #include "base/trace_event/base_tracing.h" namespace base { class Value; } namespace trace_analyzer { class QueryNode; // trace_analyzer::TraceEvent is a more convenient form of the // base::trace_event::TraceEvent class to make tracing-based tests easier to // write. struct TraceEvent { // ProcessThreadID contains a Process ID and Thread ID. struct ProcessThreadID { ProcessThreadID() : process_id(0), thread_id(0) {} ProcessThreadID(int process_id, int thread_id) : process_id(process_id), thread_id(thread_id) {} bool operator< (const ProcessThreadID& rhs) const { if (process_id != rhs.process_id) return process_id < rhs.process_id; return thread_id < rhs.thread_id; } int process_id; int thread_id; }; TraceEvent(); TraceEvent(TraceEvent&& other); ~TraceEvent(); [[nodiscard]] bool SetFromJSON(const base::Value* event_value); bool operator< (const TraceEvent& rhs) const { return timestamp < rhs.timestamp; } TraceEvent& operator=(TraceEvent&& rhs); bool has_other_event() const { return other_event; } // Returns absolute duration in microseconds between this event and other // event. Must have already verified that other_event exists by // Query(EVENT_HAS_OTHER) or by calling has_other_event(). double GetAbsTimeToOtherEvent() const; // Return the argument value if it exists and it is a string. bool GetArgAsString(const std::string& arg_name, std::string* arg) const; // Return the argument value if it exists and it is a number. bool GetArgAsNumber(const std::string& arg_name, double* arg) const; // Return the argument value if it exists and is a dictionary. bool GetArgAsDict(const std::string& arg_name, base::Value::Dict* arg) const; // Check if argument exists and is string. bool HasStringArg(const std::string& arg_name) const; // Check if argument exists and is number (double, int or bool). bool HasNumberArg(const std::string& arg_name) const; // Check if argument exists and is a dictionary. bool HasDictArg(const std::string& arg_name) const; // Get known existing arguments as specific types. // Useful when you have already queried the argument with // Query(HAS_NUMBER_ARG) or Query(HAS_STRING_ARG). std::string GetKnownArgAsString(const std::string& arg_name) const; double GetKnownArgAsDouble(const std::string& arg_name) const; int GetKnownArgAsInt(const std::string& arg_name) const; bool GetKnownArgAsBool(const std::string& arg_name) const; base::Value::Dict GetKnownArgAsDict(const std::string& arg_name) const; // Process ID and Thread ID. ProcessThreadID thread; // Time since epoch in microseconds. // Stored as double to match its JSON representation. double timestamp = 0.0; double duration = 0.0; char phase = TRACE_EVENT_PHASE_BEGIN; std::string category; std::string name; std::string id; double thread_duration = 0.0; double thread_timestamp = 0.0; std::string scope; std::string bind_id; bool flow_out = false; bool flow_in = false; std::string global_id2; std::string local_id2; // All numbers and bool values from TraceEvent args are cast to double. // bool becomes 1.0 (true) or 0.0 (false). std::map arg_numbers; std::map arg_strings; std::map arg_dicts; // The other event associated with this event (or NULL). raw_ptr other_event = nullptr; // A back-link for |other_event|. That is, if other_event is not null, then // |event->other_event->prev_event == event| is always true. raw_ptr prev_event; }; typedef std::vector TraceEventVector; class Query { public: Query(const Query& query); ~Query(); //////////////////////////////////////////////////////////////// // Query literal values // Compare with the given string. static Query String(const std::string& str); // Compare with the given number. static Query Double(double num); static Query Int(int32_t num); static Query Uint(uint32_t num); // Compare with the given bool. static Query Bool(bool boolean); // Compare with the given phase. static Query Phase(char phase); // Compare with the given string pattern. Only works with == and != operators. // Example: Query(EVENT_NAME) == Query::Pattern("MyEvent*") static Query Pattern(const std::string& pattern); //////////////////////////////////////////////////////////////// // Query event members static Query EventPid() { return Query(EVENT_PID); } static Query EventTid() { return Query(EVENT_TID); } // Return the timestamp of the event in microseconds since epoch. static Query EventTime() { return Query(EVENT_TIME); } // Return the absolute time between event and other event in microseconds. // Only works if Query::EventHasOther() == true. static Query EventDuration() { return Query(EVENT_DURATION); } // Return the duration of a COMPLETE event. static Query EventCompleteDuration() { return Query(EVENT_COMPLETE_DURATION); } static Query EventPhase() { return Query(EVENT_PHASE); } static Query EventCategory() { return Query(EVENT_CATEGORY); } static Query EventName() { return Query(EVENT_NAME); } static Query EventId() { return Query(EVENT_ID); } static Query EventPidIs(int process_id) { return Query(EVENT_PID) == Query::Int(process_id); } static Query EventTidIs(int thread_id) { return Query(EVENT_TID) == Query::Int(thread_id); } static Query EventThreadIs(const TraceEvent::ProcessThreadID& thread) { return EventPidIs(thread.process_id) && EventTidIs(thread.thread_id); } static Query EventTimeIs(double timestamp) { return Query(EVENT_TIME) == Query::Double(timestamp); } static Query EventDurationIs(double duration) { return Query(EVENT_DURATION) == Query::Double(duration); } static Query EventPhaseIs(char phase) { return Query(EVENT_PHASE) == Query::Phase(phase); } static Query EventCategoryIs(const std::string& category) { return Query(EVENT_CATEGORY) == Query::String(category); } static Query EventNameIs(const std::string& name) { return Query(EVENT_NAME) == Query::String(name); } static Query EventIdIs(const std::string& id) { return Query(EVENT_ID) == Query::String(id); } // Evaluates to true if arg exists and is a string. static Query EventHasStringArg(const std::string& arg_name) { return Query(EVENT_HAS_STRING_ARG, arg_name); } // Evaluates to true if arg exists and is a number. // Number arguments include types double, int and bool. static Query EventHasNumberArg(const std::string& arg_name) { return Query(EVENT_HAS_NUMBER_ARG, arg_name); } // Evaluates to arg value (string or number). static Query EventArg(const std::string& arg_name) { return Query(EVENT_ARG, arg_name); } // Return true if associated event exists. static Query EventHasOther() { return Query(EVENT_HAS_OTHER); } // Access the associated other_event's members: static Query OtherPid() { return Query(OTHER_PID); } static Query OtherTid() { return Query(OTHER_TID); } static Query OtherTime() { return Query(OTHER_TIME); } static Query OtherPhase() { return Query(OTHER_PHASE); } static Query OtherCategory() { return Query(OTHER_CATEGORY); } static Query OtherName() { return Query(OTHER_NAME); } static Query OtherId() { return Query(OTHER_ID); } static Query OtherPidIs(int process_id) { return Query(OTHER_PID) == Query::Int(process_id); } static Query OtherTidIs(int thread_id) { return Query(OTHER_TID) == Query::Int(thread_id); } static Query OtherThreadIs(const TraceEvent::ProcessThreadID& thread) { return OtherPidIs(thread.process_id) && OtherTidIs(thread.thread_id); } static Query OtherTimeIs(double timestamp) { return Query(OTHER_TIME) == Query::Double(timestamp); } static Query OtherPhaseIs(char phase) { return Query(OTHER_PHASE) == Query::Phase(phase); } static Query OtherCategoryIs(const std::string& category) { return Query(OTHER_CATEGORY) == Query::String(category); } static Query OtherNameIs(const std::string& name) { return Query(OTHER_NAME) == Query::String(name); } static Query OtherIdIs(const std::string& id) { return Query(OTHER_ID) == Query::String(id); } // Evaluates to true if arg exists and is a string. static Query OtherHasStringArg(const std::string& arg_name) { return Query(OTHER_HAS_STRING_ARG, arg_name); } // Evaluates to true if arg exists and is a number. // Number arguments include types double, int and bool. static Query OtherHasNumberArg(const std::string& arg_name) { return Query(OTHER_HAS_NUMBER_ARG, arg_name); } // Evaluates to arg value (string or number). static Query OtherArg(const std::string& arg_name) { return Query(OTHER_ARG, arg_name); } // Access the associated prev_event's members: static Query PrevPid() { return Query(PREV_PID); } static Query PrevTid() { return Query(PREV_TID); } static Query PrevTime() { return Query(PREV_TIME); } static Query PrevPhase() { return Query(PREV_PHASE); } static Query PrevCategory() { return Query(PREV_CATEGORY); } static Query PrevName() { return Query(PREV_NAME); } static Query PrevId() { return Query(PREV_ID); } static Query PrevPidIs(int process_id) { return Query(PREV_PID) == Query::Int(process_id); } static Query PrevTidIs(int thread_id) { return Query(PREV_TID) == Query::Int(thread_id); } static Query PrevThreadIs(const TraceEvent::ProcessThreadID& thread) { return PrevPidIs(thread.process_id) && PrevTidIs(thread.thread_id); } static Query PrevTimeIs(double timestamp) { return Query(PREV_TIME) == Query::Double(timestamp); } static Query PrevPhaseIs(char phase) { return Query(PREV_PHASE) == Query::Phase(phase); } static Query PrevCategoryIs(const std::string& category) { return Query(PREV_CATEGORY) == Query::String(category); } static Query PrevNameIs(const std::string& name) { return Query(PREV_NAME) == Query::String(name); } static Query PrevIdIs(const std::string& id) { return Query(PREV_ID) == Query::String(id); } // Evaluates to true if arg exists and is a string. static Query PrevHasStringArg(const std::string& arg_name) { return Query(PREV_HAS_STRING_ARG, arg_name); } // Evaluates to true if arg exists and is a number. // Number arguments include types double, int and bool. static Query PrevHasNumberArg(const std::string& arg_name) { return Query(PREV_HAS_NUMBER_ARG, arg_name); } // Evaluates to arg value (string or number). static Query PrevArg(const std::string& arg_name) { return Query(PREV_ARG, arg_name); } //////////////////////////////////////////////////////////////// // Common queries: // Find BEGIN events that have a corresponding END event. static Query MatchBeginWithEnd() { return (Query(EVENT_PHASE) == Query::Phase(TRACE_EVENT_PHASE_BEGIN)) && Query(EVENT_HAS_OTHER); } // Find COMPLETE events. static Query MatchComplete() { return (Query(EVENT_PHASE) == Query::Phase(TRACE_EVENT_PHASE_COMPLETE)); } // Find ASYNC_BEGIN events that have a corresponding ASYNC_END event. static Query MatchAsyncBeginWithNext() { return (Query(EVENT_PHASE) == Query::Phase(TRACE_EVENT_PHASE_ASYNC_BEGIN)) && Query(EVENT_HAS_OTHER); } // Find BEGIN events of given |name| which also have associated END events. static Query MatchBeginName(const std::string& name) { return (Query(EVENT_NAME) == Query(name)) && MatchBeginWithEnd(); } // Find COMPLETE events of given |name|. static Query MatchCompleteName(const std::string& name) { return (Query(EVENT_NAME) == Query(name)) && MatchComplete(); } // Match given Process ID and Thread ID. static Query MatchThread(const TraceEvent::ProcessThreadID& thread) { return (Query(EVENT_PID) == Query::Int(thread.process_id)) && (Query(EVENT_TID) == Query::Int(thread.thread_id)); } // Match event pair that spans multiple threads. static Query MatchCrossThread() { return (Query(EVENT_PID) != Query(OTHER_PID)) || (Query(EVENT_TID) != Query(OTHER_TID)); } //////////////////////////////////////////////////////////////// // Operators: // Boolean operators: Query operator==(const Query& rhs) const; Query operator!=(const Query& rhs) const; Query operator< (const Query& rhs) const; Query operator<=(const Query& rhs) const; Query operator> (const Query& rhs) const; Query operator>=(const Query& rhs) const; Query operator&&(const Query& rhs) const; Query operator||(const Query& rhs) const; Query operator!() const; // Arithmetic operators: // Following operators are applied to double arguments: Query operator+(const Query& rhs) const; Query operator-(const Query& rhs) const; Query operator*(const Query& rhs) const; Query operator/(const Query& rhs) const; Query operator-() const; // Mod operates on int64_t args (doubles are casted to int64_t beforehand): Query operator%(const Query& rhs) const; // Return true if the given event matches this query tree. // This is a recursive method that walks the query tree. bool Evaluate(const TraceEvent& event) const; enum TraceEventMember { EVENT_INVALID, EVENT_PID, EVENT_TID, EVENT_TIME, EVENT_DURATION, EVENT_COMPLETE_DURATION, EVENT_PHASE, EVENT_CATEGORY, EVENT_NAME, EVENT_ID, EVENT_HAS_STRING_ARG, EVENT_HAS_NUMBER_ARG, EVENT_ARG, EVENT_HAS_OTHER, EVENT_HAS_PREV, OTHER_PID, OTHER_TID, OTHER_TIME, OTHER_PHASE, OTHER_CATEGORY, OTHER_NAME, OTHER_ID, OTHER_HAS_STRING_ARG, OTHER_HAS_NUMBER_ARG, OTHER_ARG, PREV_PID, PREV_TID, PREV_TIME, PREV_PHASE, PREV_CATEGORY, PREV_NAME, PREV_ID, PREV_HAS_STRING_ARG, PREV_HAS_NUMBER_ARG, PREV_ARG, OTHER_FIRST_MEMBER = OTHER_PID, OTHER_LAST_MEMBER = OTHER_ARG, PREV_FIRST_MEMBER = PREV_PID, PREV_LAST_MEMBER = PREV_ARG, }; enum Operator { OP_INVALID, // Boolean operators: OP_EQ, OP_NE, OP_LT, OP_LE, OP_GT, OP_GE, OP_AND, OP_OR, OP_NOT, // Arithmetic operators: OP_ADD, OP_SUB, OP_MUL, OP_DIV, OP_MOD, OP_NEGATE }; enum QueryType { QUERY_BOOLEAN_OPERATOR, QUERY_ARITHMETIC_OPERATOR, QUERY_EVENT_MEMBER, QUERY_NUMBER, QUERY_STRING }; // Compare with the given member. explicit Query(TraceEventMember member); // Compare with the given member argument value. Query(TraceEventMember member, const std::string& arg_name); // Compare with the given string. explicit Query(const std::string& str); // Compare with the given number. explicit Query(double num); // Construct a boolean Query that returns (left right). Query(const Query& left, const Query& right, Operator binary_op); // Construct a boolean Query that returns ( left). Query(const Query& left, Operator unary_op); // Try to compare left_ against right_ based on operator_. // If either left or right does not convert to double, false is returned. // Otherwise, true is returned and |result| is set to the comparison result. bool CompareAsDouble(const TraceEvent& event, bool* result) const; // Try to compare left_ against right_ based on operator_. // If either left or right does not convert to string, false is returned. // Otherwise, true is returned and |result| is set to the comparison result. bool CompareAsString(const TraceEvent& event, bool* result) const; // Attempt to convert this Query to a double. On success, true is returned // and the double value is stored in |num|. bool GetAsDouble(const TraceEvent& event, double* num) const; // Attempt to convert this Query to a string. On success, true is returned // and the string value is stored in |str|. bool GetAsString(const TraceEvent& event, std::string* str) const; // Evaluate this Query as an arithmetic operator on left_ and right_. bool EvaluateArithmeticOperator(const TraceEvent& event, double* num) const; // For QUERY_EVENT_MEMBER Query: attempt to get the double value of the Query. bool GetMemberValueAsDouble(const TraceEvent& event, double* num) const; // For QUERY_EVENT_MEMBER Query: attempt to get the string value of the Query. bool GetMemberValueAsString(const TraceEvent& event, std::string* num) const; // Does this Query represent a value? bool is_value() const { return type_ != QUERY_BOOLEAN_OPERATOR; } bool is_unary_operator() const { return operator_ == OP_NOT || operator_ == OP_NEGATE; } bool is_comparison_operator() const { return operator_ != OP_INVALID && operator_ < OP_AND; } static const TraceEvent* SelectTargetEvent(const TraceEvent* ev, TraceEventMember member); const Query& left() const; const Query& right() const; private: QueryType type_; Operator operator_; scoped_refptr left_; scoped_refptr right_; TraceEventMember member_; double number_; std::string string_; bool is_pattern_; }; // Implementation detail: // QueryNode allows Query to store a ref-counted query tree. class QueryNode : public base::RefCounted { public: explicit QueryNode(const Query& query); const Query& query() const { return query_; } private: friend class base::RefCounted; ~QueryNode(); Query query_; }; // TraceAnalyzer helps tests search for trace events. class TraceAnalyzer { public: TraceAnalyzer(const TraceAnalyzer&) = delete; TraceAnalyzer& operator=(const TraceAnalyzer&) = delete; ~TraceAnalyzer(); // Use trace events from JSON string generated by tracing API. // Returns non-NULL if the JSON is successfully parsed. [[nodiscard]] static std::unique_ptr Create( const std::string& json_events); void SetIgnoreMetadataEvents(bool ignore) { ignore_metadata_events_ = ignore; } // Associate BEGIN and END events with each other. This allows Query(OTHER_*) // to access the associated event and enables Query(EVENT_DURATION). // An end event will match the most recent begin event with the same name, // category, process ID and thread ID. This matches what is shown in // about:tracing. After association, the BEGIN event will point to the // matching END event, but the END event will not point to the BEGIN event. void AssociateBeginEndEvents(); // Associate ASYNC_BEGIN, ASYNC_STEP and ASYNC_END events with each other. // An ASYNC_END event will match the most recent ASYNC_BEGIN or ASYNC_STEP // event with the same name, category, and ID. This creates a singly linked // list of ASYNC_BEGIN->ASYNC_STEP...->ASYNC_END. // |match_pid| - If true, will only match async events which are running // under the same process ID, otherwise will allow linking // async events from different processes. void AssociateAsyncBeginEndEvents(bool match_pid = true); // AssociateEvents can be used to customize event associations by setting the // other_event member of TraceEvent. This should be used to associate two // INSTANT events. // // The assumptions are: // - |first| events occur before |second| events. // - the closest matching |second| event is the correct match. // // |first| - Eligible |first| events match this query. // |second| - Eligible |second| events match this query. // |match| - This query is run on the |first| event. The OTHER_* EventMember // queries will point to an eligible |second| event. The query // should evaluate to true if the |first|/|second| pair is a match. // // When a match is found, the pair will be associated by having the first // event's other_event member point to the other. AssociateEvents does not // clear previous associations, so it is possible to associate multiple pairs // of events by calling AssociateEvents more than once with different queries. // // NOTE: AssociateEvents will overwrite existing other_event associations if // the queries pass for events that already had a previous association. // // After calling any Find* method, it is not allowed to call AssociateEvents // again. void AssociateEvents(const Query& first, const Query& second, const Query& match); // For each event, copy its arguments to the other_event argument map. If // argument name already exists, it will not be overwritten. void MergeAssociatedEventArgs(); // Find all events that match query and replace output vector. size_t FindEvents(const Query& query, TraceEventVector* output); // Find first event that matches query or NULL if not found. const TraceEvent* FindFirstOf(const Query& query); // Find last event that matches query or NULL if not found. const TraceEvent* FindLastOf(const Query& query); const std::string& GetThreadName(const TraceEvent::ProcessThreadID& thread); private: TraceAnalyzer(); [[nodiscard]] bool SetEvents(const std::string& json_events); // Read metadata (thread names, etc) from events. void ParseMetadata(); std::map thread_names_; std::vector raw_events_; bool ignore_metadata_events_; bool allow_association_changes_; }; // Utility functions for collecting process-local traces and creating a // |TraceAnalyzer| from the result. Please see comments in trace_config.h to // understand how the |category_filter_string| works. Use "*" to enable all // default categories. void Start(const std::string& category_filter_string); std::unique_ptr Stop(); // Utility functions for TraceEventVector. struct RateStats { double min_us; double max_us; double mean_us; double standard_deviation_us; }; struct RateStatsOptions { RateStatsOptions() : trim_min(0u), trim_max(0u) {} // After the times between events are sorted, the number of specified elements // will be trimmed before calculating the RateStats. This is useful in cases // where extreme outliers are tolerable and should not skew the overall // average. size_t trim_min; // Trim this many minimum times. size_t trim_max; // Trim this many maximum times. }; // Calculate min/max/mean and standard deviation from the times between // adjacent events. bool GetRateStats(const TraceEventVector& events, RateStats* stats, const RateStatsOptions* options); // Starting from |position|, find the first event that matches |query|. // Returns true if found, false otherwise. bool FindFirstOf(const TraceEventVector& events, const Query& query, size_t position, size_t* return_index); // Starting from |position|, find the last event that matches |query|. // Returns true if found, false otherwise. bool FindLastOf(const TraceEventVector& events, const Query& query, size_t position, size_t* return_index); // Find the closest events to |position| in time that match |query|. // return_second_closest may be NULL. Closeness is determined by comparing // with the event timestamp. // Returns true if found, false otherwise. If both return parameters are // requested, both must be found for a successful result. bool FindClosest(const TraceEventVector& events, const Query& query, size_t position, size_t* return_closest, size_t* return_second_closest); // Count matches, inclusive of |begin_position|, exclusive of |end_position|. size_t CountMatches(const TraceEventVector& events, const Query& query, size_t begin_position, size_t end_position); // Count all matches. inline size_t CountMatches(const TraceEventVector& events, const Query& query) { return CountMatches(events, query, 0u, events.size()); } } // namespace trace_analyzer #endif // BASE_TEST_TRACE_EVENT_ANALYZER_H_