| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef INCLUDE_PERFETTO_TRACE_PROCESSOR_ITERATOR_H_ |
| #define INCLUDE_PERFETTO_TRACE_PROCESSOR_ITERATOR_H_ |
| |
| #include <stdint.h> |
| |
| #include <memory> |
| |
| #include "perfetto/base/export.h" |
| #include "perfetto/trace_processor/basic_types.h" |
| #include "perfetto/trace_processor/status.h" |
| |
| namespace perfetto { |
| namespace trace_processor { |
| |
| class IteratorImpl; |
| |
| // Iterator returning SQL rows satisfied by a query. |
| // |
| // Example usage: |
| // auto sql = "select name, ifnull(cat, "[NULL]") from slice"; |
| // for (auto it = tp.ExecuteQuery(sql); it.Next();) |
| // for (uint32_t i = 0; i < it.ColumnCount(); ++i) { |
| // printf("%s ", it.Get(i).AsString()); |
| // } |
| // printf("\n"); |
| // } |
| class PERFETTO_EXPORT_COMPONENT Iterator { |
| public: |
| explicit Iterator(std::unique_ptr<IteratorImpl>); |
| ~Iterator(); |
| |
| Iterator(Iterator&) noexcept = delete; |
| Iterator& operator=(Iterator&) = delete; |
| |
| Iterator(Iterator&&) noexcept; |
| Iterator& operator=(Iterator&&) noexcept; |
| |
| // Forwards the iterator to the next result row and returns a boolean of |
| // whether there is a next row. If this method returns false, |
| // |Status()| should be called to check if there was an error. If |
| // there was no error, this means the EOF was reached. |
| bool Next(); |
| |
| // Returns the value associated with the column |col|. Any call to |
| // |Get()| must be preceded by a call to |Next()| returning |
| // true. |col| must be less than the number returned by |ColumnCount()|. |
| SqlValue Get(uint32_t col); |
| |
| // Returns the name of the column at index |col|. Can be called even before |
| // calling |Next()|. |
| std::string GetColumnName(uint32_t col); |
| |
| // Returns the number of columns in this iterator's query. Can be called |
| // even before calling |Next()|. |
| uint32_t ColumnCount(); |
| |
| // Returns the number of statements in the provided SQL (including the final |
| // statement which is iterated using this iterator). Comments and empty |
| // statements are *not* counted i.e. |
| // "SELECT 1; /* comment */; select 2; -- comment" |
| // returns 2 not 4. |
| uint32_t StatementCount(); |
| |
| // Returns the number of statements which produced output rows in the provided |
| // SQL (including, potentially, the final statement which is iterated using |
| // this iterator). |
| // This value is guaranteed to be <= |StatementCount()|. |
| uint32_t StatementWithOutputCount(); |
| |
| // Returns the status of the iterator. |
| util::Status Status(); |
| |
| private: |
| friend class QueryResultSerializer; |
| |
| // This is to allow QueryResultSerializer, which is very perf sensitive, to |
| // access direct the impl_ and avoid one extra function call for each cell. |
| template <typename T = IteratorImpl> |
| std::unique_ptr<T> take_impl() { |
| return std::move(iterator_); |
| } |
| |
| // A PIMPL pattern is used to avoid leaking the dependencies on sqlite3.h and |
| // other internal classes. |
| std::unique_ptr<IteratorImpl> iterator_; |
| }; |
| |
| } // namespace trace_processor |
| } // namespace perfetto |
| |
| #endif // INCLUDE_PERFETTO_TRACE_PROCESSOR_ITERATOR_H_ |