1 /*
2 * Copyright (C) 2020 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 #include "src/trace_processor/dynamic/descendant_slice_generator.h"
18
19 #include <memory>
20 #include <set>
21
22 #include "src/trace_processor/types/trace_processor_context.h"
23
24 namespace perfetto {
25 namespace trace_processor {
26
DescendantSliceGenerator(TraceProcessorContext * context)27 DescendantSliceGenerator::DescendantSliceGenerator(
28 TraceProcessorContext* context)
29 : context_(context) {}
30
31 DescendantSliceGenerator::~DescendantSliceGenerator() = default;
32
ValidateConstraints(const QueryConstraints & qc)33 util::Status DescendantSliceGenerator::ValidateConstraints(
34 const QueryConstraints& qc) {
35 const auto& cs = qc.constraints();
36
37 auto slice_id_fn = [this](const QueryConstraints::Constraint& c) {
38 return c.column == static_cast<int>(
39 context_->storage->slice_table().GetColumnCount()) &&
40 c.op == SQLITE_INDEX_CONSTRAINT_EQ;
41 };
42 bool has_slice_id_cs =
43 std::find_if(cs.begin(), cs.end(), slice_id_fn) != cs.end();
44
45 return has_slice_id_cs
46 ? util::OkStatus()
47 : util::ErrStatus("Failed to find required constraints");
48 }
49
ComputeTable(const std::vector<Constraint> & cs,const std::vector<Order> &)50 std::unique_ptr<Table> DescendantSliceGenerator::ComputeTable(
51 const std::vector<Constraint>& cs,
52 const std::vector<Order>&) {
53 const auto& slice = context_->storage->slice_table();
54
55 auto it = std::find_if(cs.begin(), cs.end(), [&slice](const Constraint& c) {
56 return c.col_idx == slice.GetColumnCount() && c.op == FilterOp::kEq;
57 });
58 PERFETTO_DCHECK(it != cs.end());
59
60 uint32_t start_id = static_cast<uint32_t>(it->value.AsLong());
61 auto descendants = GetDescendantSlices(slice, SliceId(start_id));
62 if (!descendants)
63 return nullptr;
64 Table reduced_slice = slice.Apply(std::move(*descendants));
65
66 // For every row extend it to match the schema, and return it.
67 std::unique_ptr<NullableVector<uint32_t>> start_ids(
68 new NullableVector<uint32_t>());
69 for (size_t i = 0; i < reduced_slice.row_count(); ++i) {
70 start_ids->Append(start_id);
71 }
72 return std::unique_ptr<Table>(
73 new Table(std::move(reduced_slice)
74 .ExtendWithColumn("start_id", std::move(start_ids),
75 TypedColumn<uint32_t>::default_flags() |
76 TypedColumn<uint32_t>::kHidden)));
77 }
78
CreateSchema()79 Table::Schema DescendantSliceGenerator::CreateSchema() {
80 auto schema = tables::SliceTable::Schema();
81 schema.columns.push_back(Table::Schema::Column{
82 "start_id", SqlValue::Type::kLong, /* is_id = */ false,
83 /* is_sorted = */ false, /* is_hidden = */ true});
84 return schema;
85 }
86
TableName()87 std::string DescendantSliceGenerator::TableName() {
88 return "descendant_slice";
89 }
90
EstimateRowCount()91 uint32_t DescendantSliceGenerator::EstimateRowCount() {
92 return 1;
93 }
94
95 // static
GetDescendantSlices(const tables::SliceTable & slice,SliceId start_id)96 base::Optional<RowMap> DescendantSliceGenerator::GetDescendantSlices(
97 const tables::SliceTable& slice,
98 SliceId start_id) {
99 auto start_row = slice.id().IndexOf(start_id);
100 // The query gave an invalid ID that doesn't exist in the slice table.
101 if (!start_row) {
102 // TODO(lalitm): Ideally this should result in an error, or be filtered out
103 // during ValidateConstraints so we can just dereference |start_row|
104 // directly. However ValidateConstraints doesn't know the value we're
105 // filtering for so can't ensure it exists. For now we return a nullptr
106 // which will cause the query to surface an error with the message "SQL
107 // error: constraint failed".
108 return base::nullopt;
109 }
110
111 // All nested descendents must be on the same track, with a ts between
112 // |start_id.ts| and |start_id.ts| + |start_id.dur|, and who's depth is larger
113 // then |start_row|'s. So we just use Filter to select all relevant slices.
114 return slice.FilterToRowMap(
115 {slice.ts().ge(slice.ts()[*start_row]),
116 slice.ts().le(slice.ts()[*start_row] + slice.dur()[*start_row]),
117 slice.track_id().eq(slice.track_id()[*start_row].value),
118 slice.depth().gt(slice.depth()[*start_row])});
119 }
120
121 } // namespace trace_processor
122 } // namespace perfetto
123