In #160, I wrote code which incorrectly assumed that at most one profile would be active at a time. It turns out this assumption is incorrect because of webworkers! This PR introduces a fix which correctly separates samples taken on the main thread from samples taken on worker threads, and allows viewing both in speedscope.
Fixes#171
#165 introduced a performance regression by using a really inefficient method for converting from array buffers into string. This should ix it by using `TextDecoder` instead.
Fixes#182 by adding support for importing the JSON profiling format created by GHC's built in profiling support when the executable is passed the `-pj` option. Produces a profile group containing both a time and allocation profile.
Unfortunately, GHC doesn't provide the raw sample information to get the time view to be useful, so only left heavy and sandwich are useful.
Includes a test profile, and I've also tested it on a more real large 2MB profile file in the UI and it works great.
I also modified the Readme to link to a wiki page I'm unable to create, but that should have something like this content copy-pasted into it:
# Importing from Haskell
GHC provides built in profiling support that can export a JSON file.
In order to do this you need to compile your executable with profiling
support and then pass the `-pj` RTS flag to the executable.
This will produce a `my-binary.prof` file in the current directory which
you can import into speedscope.
## Using GHC
See the [GHC manual page on profiling](https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/profiling.html)
for more extensive information on the command line flags available.
```
$ ghc -prof -fprof-auto -rtsopts Main.hs
$ ./Main +RTS -pj -RTS
```
## Using Stack
### With executables
```
$ stack build --profile
$ stack exec -- my-executable +RTS -pj -RTS
```
### With tests
```
stack test --profile --test-arguments "+RTS -pj -RTS"
```
When using #profileURL, some binary characters cannot be read if we use `fetch text`. So I changed that to use `arrayBuffer`.
Now we can read pprof protobuf files and normal JSON files instead of only text files.
This PR adds support for importing from Google's pprof format, which is a gzipped, protobuf encoded file format (that's incredibly well documented!) The [pprof http library](https://golang.org/pkg/net/http/pprof/) also offers an output of the trace file format, which continues to not be supported in speedscope to date (See #77). This will allow importing of profiles generated by the standard library go profiler for analysis of profiles containing heap allocation information, CPU profile information, and a few other things like coroutine creation information.
In order to add support for that a number of dependent bits of functionality were added, which should each provide an easier path for future binary input sources
- A protobuf decoding library was included ([protobufjs](https://www.npmjs.com/package/protobufjs)) which includes both a protobuf parser generator based on a .proto file & TypeScript definition generation from the resulting generated JavaScript file
- More generic binary file import. Before this PR, all supported sources were plaintext, with the exception of Instruments 10 support, which takes a totally different codepath. Now binary file import should work when files are dropped, opened via file browsing, or opened via invocation of the speedscope CLI.
- Transparent gzip decoding of imported files (this means that if you were to gzip compress another JSON file, then importing it should still work fine)
Fixes#60.
--
This is a [donation motivated](https://github.com/jlfwong/speedscope/issues/60#issuecomment-419660710) PR motivated by donations by @davecheney & @jmoiron to [/dev/color](https://www.devcolor.org/welcome) 🎉
It seems like #160 accidentally broken import of profiles in some circumstances from Chrome < 69. Before #160, we always took the first profile in the list *but* the profiles were not sorted chronologically. After #160 but before this PR, we were taking the chronologically first.
After this PR, we always take the chronologically last `CpuProfile` event in the trace.
This PR fixes#159, and also fixes various small things about how profiles were imported for previous versions of Chrome & for Firefox.
The Chrome 69 format splits profiles across several [Trace Event Format](https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU/preview) events. There are two relevant events: "Profile" and "ProfileChunk". At first read through a profile, it seems like profiles are incorrectly terminated, but it seems like the cause of that is that, for whatever reason, events in the event log are not always sorted in chronological order. If sorted chronologically, then the event sequence can be parsed sensibly.
In the process of looking at this information, I also discovered that speedscope's chrome importer was incorrectly interpreting the value of the first element in `timeDeltas` array. It's intended to be the elapsed time since the start of the profile, not the time between the first pair of samples. This changes the weight attributed to the first sample.
Looks like Firefox also generates locations with names like
`bound (self-hosted:951:0)`. We check for `self-hosted`, but not for
`self-hosted` with stuff after it following a colon. We should ignore
these too, otherwise we can end up with stuff on our stack that we don't
expect. This was causing Firefox profiles not to load because we
completed building the profile with a non-empty stack.
Attached is a profile that errors without this patch and successfully renders
with this patch.
[copy.json.zip](https://github.com/jlfwong/speedscope/files/2350583/copy.json.zip)
The problem was that I was using `canvas.getBoundingClientRect()` to get the size to resize to, but that was changing as the result of CSS properties set on the canvas! Instead, we take the measurements of its container now which is set to fill the screen, and the canvas has its size entirely managed by `graphics.ts`.
