1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
// Copyright Materialize, Inc. and contributors. All rights reserved.
//
// Use of this software is governed by the Business Source License
// included in the LICENSE file.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0.

//! Profiling HTTP endpoints.

use std::env;
use std::time::Duration;

use askama::Template;
use axum::response::IntoResponse;
use axum::routing::{self, Router};
use cfg_if::cfg_if;
use http::StatusCode;
use mz_build_info::BuildInfo;
use once_cell::sync::Lazy;

use crate::{ProfStartTime, StackProfile};

cfg_if! {
    if #[cfg(any(target_os = "macos", not(feature = "jemalloc"), miri))] {
        use disabled::{handle_get, handle_post, handle_get_heap};
    } else {
        use enabled::{handle_get, handle_post, handle_get_heap};
    }
}

static EXECUTABLE: Lazy<String> = Lazy::new(|| {
    {
        env::current_exe()
            .ok()
            .as_ref()
            .and_then(|exe| exe.file_name())
            .map(|exe| exe.to_string_lossy().into_owned())
            .unwrap_or_else(|| "<unknown executable>".into())
    }
});

mz_http_util::make_handle_static!(
    include_dir::include_dir!("$CARGO_MANIFEST_DIR/src/http/static"),
    "src/http/static",
    "src/http/static-dev"
);

/// Creates a router that serves the profiling endpoints.
pub fn router(build_info: &'static BuildInfo) -> Router {
    Router::new()
        .route(
            "/",
            routing::get(move |query, headers| handle_get(query, headers, build_info)),
        )
        .route(
            "/",
            routing::post(move |form| handle_post(form, build_info)),
        )
        .route("/heap", routing::get(handle_get_heap))
        .route("/static/*path", routing::get(handle_static))
}

#[allow(dead_code)]
enum MemProfilingStatus {
    Disabled,
    Enabled(Option<ProfStartTime>),
}

#[derive(Template)]
#[template(path = "http/templates/prof.html")]
struct ProfTemplate<'a> {
    version: &'a str,
    executable: &'a str,
    mem_prof: MemProfilingStatus,
    ever_symbolized: bool,
}

#[derive(Template)]
#[template(path = "http/templates/flamegraph.html")]
pub struct FlamegraphTemplate<'a> {
    pub version: &'a str,
    pub title: &'a str,
    pub mzfg: &'a str,
}

#[allow(dropping_copy_types)]
async fn time_prof<'a>(
    merge_threads: bool,
    build_info: &BuildInfo,
    // the time in seconds to run the profiler for
    time_secs: u64,
    // the sampling frequency in Hz
    sample_freq: u32,
) -> impl IntoResponse {
    let ctl_lock;
    cfg_if! {
        if #[cfg(any(target_os = "macos", not(feature = "jemalloc"), miri))] {
            ctl_lock = ();
        } else {
            ctl_lock = if let Some(ctl) = crate::jemalloc::PROF_CTL.as_ref() {
                let mut borrow = ctl.lock().await;
                borrow.deactivate().map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                Some(borrow)
            } else {
                None
            };
        }
    }
    // SAFETY: We ensure above that memory profiling is off.
    // Since we hold the mutex, nobody else can be turning it back on in the intervening time.
    let stacks = unsafe {
        crate::time::prof_time(Duration::from_secs(time_secs), sample_freq, merge_threads)
    }
    .await
    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
    // Fail with a compile error if we weren't holding the jemalloc lock.
    drop(ctl_lock);
    let (secs_s, freq_s) = (format!("{time_secs}"), format!("{sample_freq}"));
    Ok::<_, (StatusCode, String)>(flamegraph(
        stacks,
        "CPU Time Flamegraph",
        false,
        &[
            ("Sampling time (s)", &secs_s),
            ("Sampling frequency (Hz)", &freq_s),
        ],
        build_info,
    ))
}

fn flamegraph(
    stacks: StackProfile,
    title: &str,
    display_bytes: bool,
    extras: &[(&str, &str)],
    build_info: &BuildInfo,
) -> impl IntoResponse {
    let mut header_extra = vec![];
    if display_bytes {
        header_extra.push(("display_bytes", "1"));
    }
    for (k, v) in extras {
        header_extra.push((k, v));
    }
    let mzfg = stacks.to_mzfg(true, &header_extra);
    mz_http_util::template_response(FlamegraphTemplate {
        version: build_info.version,
        title,
        mzfg: &mzfg,
    })
}

#[cfg(any(target_os = "macos", not(feature = "jemalloc"), miri))]
mod disabled {
    use axum::extract::{Form, Query};
    use axum::response::IntoResponse;
    use http::header::HeaderMap;
    use http::StatusCode;
    use mz_build_info::BuildInfo;
    use serde::Deserialize;

    use crate::ever_symbolized;

    use super::{time_prof, MemProfilingStatus, ProfTemplate};

    #[derive(Deserialize)]
    pub struct ProfQuery {
        _action: Option<String>,
    }

    #[allow(clippy::unused_async)]
    pub async fn handle_get(
        _: Query<ProfQuery>,
        _: HeaderMap,
        build_info: &'static BuildInfo,
    ) -> impl IntoResponse {
        mz_http_util::template_response(ProfTemplate {
            version: build_info.version,
            executable: &super::EXECUTABLE,
            mem_prof: MemProfilingStatus::Disabled,
            ever_symbolized: ever_symbolized(),
        })
    }

    #[derive(Deserialize)]
    pub struct ProfForm {
        action: String,
        threads: Option<String>,
        time_secs: Option<u64>,
        hz: Option<u32>,
    }

    pub async fn handle_post(
        Form(ProfForm {
            action,
            threads,
            time_secs,
            hz,
        }): Form<ProfForm>,
        build_info: &'static BuildInfo,
    ) -> impl IntoResponse {
        let merge_threads = threads.as_deref() == Some("merge");
        match action.as_ref() {
            "time_fg" => {
                let time_secs = time_secs.ok_or_else(|| {
                    (
                        StatusCode::BAD_REQUEST,
                        "Expected value for `time_secs`".to_owned(),
                    )
                })?;
                let hz = hz.ok_or_else(|| {
                    (
                        StatusCode::BAD_REQUEST,
                        "Expected value for `hz`".to_owned(),
                    )
                })?;

                Ok(time_prof(merge_threads, build_info, time_secs, hz).await)
            }
            _ => Err((
                StatusCode::BAD_REQUEST,
                format!("unrecognized `action` parameter: {}", action),
            )),
        }
    }

    #[allow(clippy::unused_async)]
    pub async fn handle_get_heap() -> Result<(), (StatusCode, String)> {
        Err((
            StatusCode::BAD_REQUEST,
            "This software was compiled without heap profiling support.".to_string(),
        ))
    }
}

#[cfg(all(not(target_os = "macos"), feature = "jemalloc", not(miri)))]
mod enabled {
    use std::io::{BufReader, Read};
    use std::sync::Arc;

    use axum::extract::{Form, Query};
    use axum::response::IntoResponse;
    use axum::TypedHeader;
    use bytesize::ByteSize;
    use headers::ContentType;
    use http::header::{HeaderMap, CONTENT_DISPOSITION};
    use http::{HeaderValue, StatusCode};
    use mz_build_info::BuildInfo;
    use mz_ore::cast::CastFrom;
    use serde::Deserialize;
    use tokio::sync::Mutex;

    use crate::ever_symbolized;
    use crate::jemalloc::{parse_jeheap, JemallocProfCtl, JemallocStats, PROF_CTL};

    use super::{flamegraph, time_prof, MemProfilingStatus, ProfTemplate};

    #[derive(Deserialize)]
    pub struct ProfForm {
        action: String,
        threads: Option<String>,
        time_secs: Option<u64>,
        hz: Option<u32>,
    }

    pub async fn handle_post(
        Form(ProfForm {
            action,
            threads,
            time_secs,
            hz,
        }): Form<ProfForm>,
        build_info: &'static BuildInfo,
    ) -> impl IntoResponse {
        let prof_ctl = PROF_CTL.as_ref().unwrap();
        let merge_threads = threads.as_deref() == Some("merge");

        fn render_jemalloc_stats(stats: &JemallocStats) -> Vec<(&str, String)> {
            vec![
                (
                    "Allocated",
                    ByteSize(u64::cast_from(stats.allocated)).to_string_as(true),
                ),
                (
                    "In active pages",
                    ByteSize(u64::cast_from(stats.active)).to_string_as(true),
                ),
                (
                    "Allocated for allocator metadata",
                    ByteSize(u64::cast_from(stats.metadata)).to_string_as(true),
                ),
                // Don't print `stats.resident` since it is a bit hard to interpret;
                // see `man jemalloc` for details.
                (
                    "Bytes unused, but retained by allocator",
                    ByteSize(u64::cast_from(stats.retained)).to_string_as(true),
                ),
            ]
        }

        match action.as_str() {
            "activate" => {
                {
                    let mut borrow = prof_ctl.lock().await;
                    borrow
                        .activate()
                        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                };
                Ok(render_template(prof_ctl, build_info).await.into_response())
            }
            "deactivate" => {
                {
                    let mut borrow = prof_ctl.lock().await;
                    borrow
                        .deactivate()
                        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                };
                Ok(render_template(prof_ctl, build_info).await.into_response())
            }
            "dump_jeheap" => {
                let mut borrow = prof_ctl.lock().await;
                require_profiling_activated(&borrow)?;
                let mut f = borrow
                    .dump()
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let mut s = String::new();
                f.read_to_string(&mut s)
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                Ok((
                    HeaderMap::from_iter([(
                        CONTENT_DISPOSITION,
                        HeaderValue::from_static("attachment; filename=\"jeprof.heap\""),
                    )]),
                    s,
                )
                    .into_response())
            }
            "dump_sym_mzfg" => {
                let mut borrow = prof_ctl.lock().await;
                require_profiling_activated(&borrow)?;
                let f = borrow
                    .dump()
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let r = BufReader::new(f);
                let stacks = parse_jeheap(r)
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let stats = borrow
                    .stats()
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let stats_rendered = render_jemalloc_stats(&stats);
                let mut header = stats_rendered
                    .iter()
                    .map(|(k, v)| (*k, v.as_str()))
                    .collect::<Vec<_>>();
                header.push(("display_bytes", "1"));
                let mzfg = stacks.to_mzfg(true, &header);
                Ok((
                    HeaderMap::from_iter([(
                        CONTENT_DISPOSITION,
                        HeaderValue::from_static("attachment; filename=\"trace.mzfg\""),
                    )]),
                    mzfg,
                )
                    .into_response())
            }
            "mem_fg" => {
                let mut borrow = prof_ctl.lock().await;
                require_profiling_activated(&borrow)?;
                let f = borrow
                    .dump()
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let r = BufReader::new(f);
                let stacks = parse_jeheap(r)
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let stats = borrow
                    .stats()
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let stats_rendered = render_jemalloc_stats(&stats);
                let stats_rendered = stats_rendered
                    .iter()
                    .map(|(k, v)| (*k, v.as_str()))
                    .collect::<Vec<_>>();
                Ok(
                    flamegraph(stacks, "Heap Flamegraph", true, &stats_rendered, build_info)
                        .into_response(),
                )
            }
            "time_fg" => {
                let time_secs = time_secs.ok_or_else(|| {
                    (
                        StatusCode::BAD_REQUEST,
                        "Expected value for `time_secs`".to_owned(),
                    )
                })?;
                let hz = hz.ok_or_else(|| {
                    (
                        StatusCode::BAD_REQUEST,
                        "Expected value for `hz`".to_owned(),
                    )
                })?;
                Ok(time_prof(merge_threads, build_info, time_secs, hz)
                    .await
                    .into_response())
            }
            x => Err((
                StatusCode::BAD_REQUEST,
                format!("unrecognized `action` parameter: {}", x),
            )),
        }
    }

    #[derive(Deserialize)]
    pub struct ProfQuery {
        action: Option<String>,
    }

    pub async fn handle_get(
        Query(query): Query<ProfQuery>,
        headers: HeaderMap,
        build_info: &'static BuildInfo,
    ) -> impl IntoResponse {
        let prof_ctl = PROF_CTL.as_ref().unwrap();
        match query.action.as_deref() {
            Some("dump_stats") => {
                let json = headers
                    .get("accept")
                    .map_or(false, |accept| accept.as_bytes() == b"application/json");
                let mut borrow = prof_ctl.lock().await;
                let s = borrow
                    .dump_stats(json)
                    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
                let content_type = match json {
                    false => ContentType::text(),
                    true => ContentType::json(),
                };
                Ok((TypedHeader(content_type), s).into_response())
            }
            Some(x) => Err((
                StatusCode::BAD_REQUEST,
                format!("unrecognized query: {}", x),
            )),
            None => Ok(render_template(prof_ctl, build_info).await.into_response()),
        }
    }

    pub async fn handle_get_heap() -> Result<impl IntoResponse, (StatusCode, String)> {
        let mut prof_ctl = PROF_CTL.as_ref().unwrap().lock().await;
        require_profiling_activated(&prof_ctl)?;
        let dump_file = prof_ctl
            .dump()
            .map_err(|err| (StatusCode::INTERNAL_SERVER_ERROR, err.to_string()))?;
        let dump_reader = BufReader::new(dump_file);
        let profile = parse_jeheap(dump_reader)
            .map_err(|err| (StatusCode::INTERNAL_SERVER_ERROR, err.to_string()))?;
        let pprof = profile.to_pprof(("inuse_space", "bytes"), ("space", "bytes"), None);
        Ok(pprof)
    }

    async fn render_template(
        prof_ctl: &Arc<Mutex<JemallocProfCtl>>,
        build_info: &'static BuildInfo,
    ) -> impl IntoResponse {
        let prof_md = prof_ctl.lock().await.get_md();
        mz_http_util::template_response(ProfTemplate {
            version: build_info.version,
            executable: &super::EXECUTABLE,
            mem_prof: MemProfilingStatus::Enabled(prof_md.start_time),
            ever_symbolized: ever_symbolized(),
        })
    }

    /// Checks whether jemalloc profiling is activated an returns an error response if not.
    fn require_profiling_activated(prof_ctl: &JemallocProfCtl) -> Result<(), (StatusCode, String)> {
        if prof_ctl.activated() {
            Ok(())
        } else {
            Err((StatusCode::FORBIDDEN, "heap profiling not activated".into()))
        }
    }
}