| /* |
| * Copyright (C) 2019 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 SRC_TRACE_PROCESSOR_DB_TABLE_H_ |
| #define SRC_TRACE_PROCESSOR_DB_TABLE_H_ |
| |
| #include <stdint.h> |
| |
| #include <limits> |
| #include <numeric> |
| #include <vector> |
| |
| #include "perfetto/base/logging.h" |
| #include "perfetto/ext/base/optional.h" |
| #include "src/trace_processor/containers/string_pool.h" |
| #include "src/trace_processor/db/column.h" |
| #include "src/trace_processor/db/column_storage_overlay.h" |
| #include "src/trace_processor/db/typed_column.h" |
| |
| namespace perfetto { |
| namespace trace_processor { |
| |
| // Represents a table of data with named, strongly typed columns. |
| class Table { |
| public: |
| // Iterator over the rows of the table. |
| class Iterator { |
| public: |
| explicit Iterator(const Table* table) : table_(table) { |
| its_.reserve(table->overlays().size()); |
| for (const auto& rm : table->overlays()) { |
| its_.emplace_back(rm.IterateRows()); |
| } |
| } |
| |
| Iterator(Iterator&&) noexcept = default; |
| Iterator& operator=(Iterator&&) = default; |
| |
| Iterator(const Iterator&) = delete; |
| Iterator& operator=(const Iterator&) = delete; |
| |
| // Advances the iterator to the next row of the table. |
| void Next() { |
| for (auto& it : its_) { |
| it.Next(); |
| } |
| } |
| |
| // Returns whether the row the iterator is pointing at is valid. |
| explicit operator bool() const { return its_[0]; } |
| |
| // Returns the value at the current row for column |col_idx|. |
| SqlValue Get(uint32_t col_idx) const { |
| const auto& col = table_->columns_[col_idx]; |
| return col.GetAtIdx(its_[col.overlay_index()].index()); |
| } |
| |
| private: |
| const Table* table_ = nullptr; |
| std::vector<ColumnStorageOverlay::Iterator> its_; |
| }; |
| |
| // Helper class storing the schema of the table. This allows decisions to be |
| // made about operations on the table without materializing the table - this |
| // may be expensive for dynamically computed tables. |
| // |
| // Subclasses of Table usually provide a method (named Schema()) to statically |
| // generate an instance of this class. |
| struct Schema { |
| struct Column { |
| std::string name; |
| SqlValue::Type type; |
| bool is_id; |
| bool is_sorted; |
| bool is_hidden; |
| bool is_set_id; |
| }; |
| std::vector<Column> columns; |
| }; |
| |
| Table(); |
| virtual ~Table(); |
| |
| // We explicitly define the move constructor here because we need to update |
| // the Table pointer in each column in the table. |
| Table(Table&& other) noexcept { *this = std::move(other); } |
| Table& operator=(Table&& other) noexcept; |
| |
| // Filters the Table using the specified filter constraints. |
| Table Filter( |
| const std::vector<Constraint>& cs, |
| RowMap::OptimizeFor optimize_for = RowMap::OptimizeFor::kMemory) const { |
| if (cs.empty()) |
| return Copy(); |
| return Apply(FilterToRowMap(cs, optimize_for)); |
| } |
| |
| // Filters the Table using the specified filter constraints optionally |
| // specifying what the returned RowMap should optimize for. |
| // Returns a RowMap which, if applied to the table, would contain the rows |
| // post filter. |
| RowMap FilterToRowMap( |
| const std::vector<Constraint>& cs, |
| RowMap::OptimizeFor optimize_for = RowMap::OptimizeFor::kMemory) const { |
| RowMap rm(0, row_count_, optimize_for); |
| for (const Constraint& c : cs) { |
| columns_[c.col_idx].FilterInto(c.op, c.value, &rm); |
| } |
| return rm; |
| } |
| |
| // Applies the given RowMap to the current table by picking out the rows |
| // specified in the RowMap to be present in the output table. |
| // Note: the RowMap should not reorder this table; this is guaranteed if the |
| // passed RowMap is generated using |FilterToRowMap|. |
| Table Apply(RowMap rm) const { |
| Table table = CopyExceptRowMaps(); |
| table.row_count_ = rm.size(); |
| table.overlays_.reserve(overlays_.size()); |
| for (const ColumnStorageOverlay& map : overlays_) { |
| table.overlays_.emplace_back(map.SelectRows(rm)); |
| PERFETTO_DCHECK(table.overlays_.back().size() == table.row_count()); |
| } |
| // Pretty much any application of a RowMap will break the requirements on |
| // kSetId so remove it. |
| for (auto& col : table.columns_) { |
| col.flags_ &= ~Column::Flag::kSetId; |
| } |
| return table; |
| } |
| |
| // Sorts the Table using the specified order by constraints. |
| Table Sort(const std::vector<Order>& od) const; |
| |
| // Returns the column at index |idx| in the Table. |
| const Column& GetColumn(uint32_t idx) const { return columns_[idx]; } |
| |
| // Returns the column index with the given name or base::nullopt otherwise. |
| base::Optional<uint32_t> GetColumnIndexByName(const char* name) const { |
| auto it = std::find_if( |
| columns_.begin(), columns_.end(), |
| [name](const Column& col) { return strcmp(col.name(), name) == 0; }); |
| if (it == columns_.end()) |
| return base::nullopt; |
| return static_cast<uint32_t>(std::distance(columns_.begin(), it)); |
| } |
| |
| // Returns the column with the given name or nullptr otherwise. |
| const Column* GetColumnByName(const char* name) const { |
| base::Optional<uint32_t> opt_idx = GetColumnIndexByName(name); |
| if (!opt_idx) |
| return nullptr; |
| return &columns_[*opt_idx]; |
| } |
| |
| template <typename T> |
| const TypedColumn<T>& GetTypedColumnByName(const char* name) const { |
| return *TypedColumn<T>::FromColumn(GetColumnByName(name)); |
| } |
| |
| template <typename T> |
| const IdColumn<T>& GetIdColumnByName(const char* name) const { |
| return *IdColumn<T>::FromColumn(GetColumnByName(name)); |
| } |
| |
| // Returns the number of columns in the Table. |
| uint32_t GetColumnCount() const { |
| return static_cast<uint32_t>(columns_.size()); |
| } |
| |
| // Returns an iterator into the Table. |
| Iterator IterateRows() const { return Iterator(this); } |
| |
| // Creates a copy of this table. |
| Table Copy() const; |
| |
| // Computes the schema of this table and returns it. |
| Schema ComputeSchema() const { |
| Schema schema; |
| schema.columns.reserve(columns_.size()); |
| for (const auto& col : columns_) { |
| schema.columns.emplace_back( |
| Schema::Column{col.name(), col.type(), col.IsId(), col.IsSorted(), |
| col.IsHidden(), col.IsSetId()}); |
| } |
| return schema; |
| } |
| |
| uint32_t row_count() const { return row_count_; } |
| StringPool* string_pool() const { return string_pool_; } |
| const std::vector<ColumnStorageOverlay>& overlays() const { |
| return overlays_; |
| } |
| const std::vector<Column>& columns() const { return columns_; } |
| |
| protected: |
| explicit Table(StringPool* pool); |
| |
| std::vector<ColumnStorageOverlay> CopyOverlays() const { |
| std::vector<ColumnStorageOverlay> rm(overlays_.size()); |
| for (uint32_t i = 0; i < overlays_.size(); ++i) { |
| rm[i] = overlays_[i].Copy(); |
| } |
| return rm; |
| } |
| |
| std::vector<ColumnStorageOverlay> overlays_; |
| std::vector<Column> columns_; |
| uint32_t row_count_ = 0; |
| |
| StringPool* string_pool_ = nullptr; |
| |
| private: |
| friend class Column; |
| friend class View; |
| |
| Table CopyExceptRowMaps() const; |
| }; |
| |
| } // namespace trace_processor |
| } // namespace perfetto |
| |
| #endif // SRC_TRACE_PROCESSOR_DB_TABLE_H_ |