1 /* 2 * Copyright (C) 2021 The Android Open Source Project 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 #ifndef SRC_TRACE_PROCESSOR_PERFETTO_SQL_INTRINSICS_TABLE_FUNCTIONS_EXPERIMENTAL_FLAT_SLICE_H_ 18 #define SRC_TRACE_PROCESSOR_PERFETTO_SQL_INTRINSICS_TABLE_FUNCTIONS_EXPERIMENTAL_FLAT_SLICE_H_ 19 20 #include <cstdint> 21 #include <memory> 22 #include <string> 23 #include <vector> 24 25 #include "perfetto/ext/base/status_or.h" 26 #include "perfetto/trace_processor/basic_types.h" 27 #include "src/trace_processor/containers/string_pool.h" 28 #include "src/trace_processor/db/table.h" 29 #include "src/trace_processor/perfetto_sql/intrinsics/table_functions/static_table_function.h" 30 #include "src/trace_processor/tables/slice_tables_py.h" 31 32 namespace perfetto { 33 namespace trace_processor { 34 35 class TraceProcessorContext; 36 37 // Dynamic table generator for "flat slice" table. 38 // 39 // The concept of a "flat slice" is to take the data in the slice table and 40 // remove all notion of nesting; we do this by, at any point in time, taking the 41 // most specific active slice (i.e. the slice at the bottom of the stack) and 42 // representing that as the *only* slice that was running during that period. 43 // 44 // This concept becomes very useful when you try and linearise a trace and 45 // compare it with other traces spanning the same user action; "self time" (i.e. 46 // time spent in a slice but *not* any children) is easily computed and span 47 // joins with thread state become possible without limiting to only depth zero 48 // slices. 49 // 50 // This table also adds "gap slices" which fill in the gap between top level 51 // slices with a sentinal values so that comparision of the gap between slices 52 // is also possible. 53 // 54 // As input, this generator takes a start and end timestamp between 55 // which slices should be picked; we do this rather than just using the trace 56 // bounds so that the "gap slices" start and end at the appropriate place. 57 // 58 // Note that for the start bound we will *not* pick any slice which started 59 // before the bound even if it finished after. This is dissimilar to span join 60 // (which picks all slices with ts + dur >= bound) and is more akin to doing 61 // a simple ts >= bound. However, slices *will* be truncated at the end 62 // if they would spill past the provided end bound. 63 class ExperimentalFlatSlice : public StaticTableFunction { 64 public: 65 explicit ExperimentalFlatSlice(TraceProcessorContext* context); 66 67 Table::Schema CreateSchema() override; 68 std::string TableName() override; 69 uint32_t EstimateRowCount() override; 70 base::StatusOr<std::unique_ptr<Table>> ComputeTable( 71 const std::vector<SqlValue>& arguments) override; 72 73 // Visibile for testing. 74 static std::unique_ptr<tables::ExperimentalFlatSliceTable> 75 ComputeFlatSliceTable(const tables::SliceTable&, 76 StringPool*, 77 int64_t start_bound, 78 int64_t end_bound); 79 80 private: 81 TraceProcessorContext* context_ = nullptr; 82 }; 83 84 } // namespace trace_processor 85 } // namespace perfetto 86 87 #endif // SRC_TRACE_PROCESSOR_PERFETTO_SQL_INTRINSICS_TABLE_FUNCTIONS_EXPERIMENTAL_FLAT_SLICE_H_ 88