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/importers/ninja/ninja_log_parser.h"
18
19 #include <stdio.h>
20 #include <algorithm>
21 #include <cstdint>
22 #include <cstring>
23 #include <vector>
24
25 #include "perfetto/base/status.h"
26 #include "perfetto/ext/base/string_splitter.h"
27 #include "perfetto/ext/base/string_utils.h"
28 #include "perfetto/ext/base/string_view.h"
29 #include "perfetto/trace_processor/trace_blob_view.h"
30 #include "src/trace_processor/importers/common/process_tracker.h"
31 #include "src/trace_processor/importers/common/slice_tracker.h"
32 #include "src/trace_processor/importers/common/track_tracker.h"
33 #include "src/trace_processor/storage/stats.h"
34 #include "src/trace_processor/storage/trace_storage.h"
35
36 namespace perfetto::trace_processor {
37
38 using base::StringSplitter;
39
NinjaLogParser(TraceProcessorContext * ctx)40 NinjaLogParser::NinjaLogParser(TraceProcessorContext* ctx) : ctx_(ctx) {}
41 NinjaLogParser::~NinjaLogParser() = default;
42
Parse(TraceBlobView blob)43 base::Status NinjaLogParser::Parse(TraceBlobView blob) {
44 // A trace is read in chunks of arbitrary size (for http fetch() pipeliniing),
45 // not necessarily aligned on a line boundary.
46 // Here we push everything into a vector and, on each call, consume only
47 // the leading part until the last \n, keeping the rest for the next call.
48 const char* src = reinterpret_cast<const char*>(blob.data());
49 log_.insert(log_.end(), src, src + blob.size());
50
51 // Find the last \n.
52 size_t valid_size = log_.size();
53 for (; valid_size > 0 && log_[valid_size - 1] != '\n'; --valid_size) {
54 }
55
56 for (StringSplitter line(log_.data(), valid_size, '\n'); line.Next();) {
57 static const char kHeader[] = "# ninja log v";
58 if (!header_parsed_) {
59 if (!base::StartsWith(line.cur_token(), kHeader))
60 return base::ErrStatus("Failed to parse ninja log header");
61 header_parsed_ = true;
62 auto version = base::CStringToUInt32(line.cur_token() + strlen(kHeader));
63 if (!version || *version != 5)
64 return base::ErrStatus("Unsupported ninja log version");
65 continue;
66 }
67
68 // Each line in the ninja log looks like this:
69 // 4 12 1579224178 ui/assets/modal.scss 832a958a9e234dfa
70 // Where:
71 // - [4, 12] are the timestamps in ms of [start, end] of the job, measured
72 // from the beginning of the build.
73 // - 1579224178 is the "restat" (ignored).
74 // - ui/assets/modal.scss is the name of the output file being built.
75 // - 832a958a9e234dfa is a hash of the compiler invocation.
76 // In most cases, each hash should be unique per ninja invocation (because
77 // two rules shouln't generate the same output). However, in rare
78 // circumstances the same hash can show up more than once. Examples:
79 // - A GN action generates > 1 output per invocation (e.g., protos). In this
80 // case all items will have the same [start, end] timestamp. In this case
81 // we want to merge all the output names into one build step, because from
82 // the build system viewpoint, that was the same compiler/tool invocation.
83 // - A subtle script that generates different outputs without taking a
84 // --output=filename argument (e.g. via env vars or similar). Note that
85 // this happens in the perfetto codebase itself (goto.google.com/nigew).
86 // In this case we want to treat the two entries as two distinct jobs.
87 //
88 // In summary the deduping logic here is: if both the hash and the
89 // timestamps match -> merge, if not, keep distinct.
90 StringSplitter tok(&line, '\t');
91 auto t_start = base::CStringToInt64(tok.Next() ? tok.cur_token() : "");
92 auto t_end = base::CStringToInt64(tok.Next() ? tok.cur_token() : "");
93 tok.Next(); // Ignore restat.
94 const char* name = tok.Next() ? tok.cur_token() : nullptr;
95 auto cmdhash = base::CStringToUInt64(tok.Next() ? tok.cur_token() : "", 16);
96
97 if (!t_start || !t_end || !name || !cmdhash) {
98 ctx_->storage->IncrementStats(stats::ninja_parse_errors);
99 continue;
100 }
101
102 // If more hashes show up back-to-back with the same timestamps, merge them
103 // together as they identify multiple outputs for the same build rule.
104 // TODO(lalitm): this merging should really happen in NotifyEndOfFile
105 // because we want to merge across builds. However, this needs some
106 // non-significant rework of this class so it's not been found to be worth
107 // implementing yet.
108 if (!jobs_.empty() && *cmdhash == jobs_.back().hash &&
109 *t_start == jobs_.back().start_ms && *t_end == jobs_.back().end_ms) {
110 jobs_.back().names.append(" ");
111 jobs_.back().names.append(name);
112 continue;
113 }
114
115 jobs_.emplace_back(*t_start, *t_end, *cmdhash, name);
116 }
117 log_.erase(log_.begin(), log_.begin() + static_cast<ssize_t>(valid_size));
118 return base::OkStatus();
119 }
120
121 // This is called after the last Parse() call. At this point all |jobs_| have
122 // been populated.
NotifyEndOfFile()123 base::Status NinjaLogParser::NotifyEndOfFile() {
124 std::sort(jobs_.begin(), jobs_.end(),
125 [](const Job& x, const Job& y) { return x.start_ms < y.start_ms; });
126
127 // Now we need to work out the job parallelism. There's no direct indication
128 // of that in the ninja logs, so it must be inferred by observing overlapping
129 // of timestamps. In this context a "Worker" is an inferred sequence of jobs
130 // that happened concurrently with other sequences.
131 // Here we pack jobs according the following heuristic, for the sake of making
132 // the graph nicer to read to humans. Consider the initial situation:
133 // 1: [ job 1 ]
134 // 2: [ job 2 ]
135 // 3: [ job 3 ]
136 // T=0 | T=6
137 // Assume that a new job starts at T=6. It's very likely that job4 was started
138 // as a consequence of job2 completion (othewise it could have been started
139 // earlier, soon after job 1 or Job 3). It seems to make more sense to draw
140 // it next in the 2nd worker, i.e. next to job 2.
141 struct Worker {
142 int64_t busy_until;
143 TrackId track_id;
144 };
145 std::vector<Worker> workers;
146 for (const auto& job : jobs_) {
147 Worker* worker = nullptr;
148 for (Worker& cur : workers) {
149 // Pick the worker which has the greatest end time (busy_until) <= the
150 // job's start time.
151 if (cur.busy_until <= job.start_ms) {
152 if (!worker || worker->busy_until < cur.busy_until)
153 worker = &cur;
154 }
155 }
156 if (worker) {
157 // Update the worker's end time with the newly assigned job.
158 worker->busy_until = job.end_ms;
159 } else {
160 static constexpr uint32_t kSyntheticNinjaPid = 1;
161
162 // All workers are busy, allocate a new one.
163 uint32_t worker_id = static_cast<uint32_t>(workers.size()) + 1;
164 ctx_->process_tracker->SetProcessNameIfUnset(
165 ctx_->process_tracker->GetOrCreateProcess(kSyntheticNinjaPid),
166 ctx_->storage->InternString("Build"));
167 auto utid =
168 ctx_->process_tracker->UpdateThread(worker_id, kSyntheticNinjaPid);
169
170 base::StackString<32> name("Worker");
171 StringId name_id = ctx_->storage->InternString(name.string_view());
172 ctx_->process_tracker->UpdateThreadNameByUtid(utid, name_id,
173 ThreadNamePriority::kOther);
174 TrackId track_id = ctx_->track_tracker->InternThreadTrack(utid);
175 workers.emplace_back(Worker{/*busy_until=*/job.end_ms, track_id});
176 worker = &workers.back();
177 }
178
179 static constexpr int64_t kMsToNs = 1000ul * 1000;
180 const int64_t start_ns = job.start_ms * kMsToNs;
181 const int64_t dur_ns = (job.end_ms - job.start_ms) * kMsToNs;
182 StringId name_id = ctx_->storage->InternString(base::StringView(job.names));
183 ctx_->slice_tracker->Scoped(start_ns, worker->track_id, StringId::Null(),
184 name_id, dur_ns);
185 }
186 return base::OkStatus();
187 }
188
189 } // namespace perfetto::trace_processor
190