Add support for writing out Speedscope files

This adds support for writing out speedscope files, as well as writing out raw
call stack data. The speedscope code is adapted from rbspy.

This change also refactors the commandline arguments significantly, changing
to take subcommands (```py-spy dump -p 1234```) instead of flags. While this
is a breaking change, I think it is a better long term solution for py-spy
- and it makes more sense for the '-f' flag to be the file format and '-o'
to be the filename (which would have broken commandline compatability anyways).

CHANGELOG.md

@@ -1,3 +1,15 @@
+## v0.2.0 (pre-release)
+
+* Add ability to profile native python extensions [#2](https://github.com/benfred/py-spy/issues/2)
+* Add FreeBSD support [#112](https://github.com/benfred/py-spy/issues/112)
+* Add option to write out Speedscope files [#115](https://github.com/benfred/py-spy/issues/115)
+* Add option to output raw call stack data [#35](https://github.com/benfred/py-spy/issues/35)
+* Get thread idle status from OS [#92](https://github.com/benfred/py-spy/issues/92)
+* Allow use as a library by other rust programs [#110](https://github.com/benfred/py-spy/issues/110)
+* Show OS threadids in --dump [#57](https://github.com/benfred/py-spy/issues/57)
+* Drop root permissions when starting new process [#116](https://github.com/benfred/py-spy/issues/116)
+* Support building for ARM procesesors [#89](https://github.com/benfred/py-spy/issues/89)
+
 ## v0.1.11
 
 * Fix to detect GIL status on Python 3.7+ [#104](https://github.com/benfred/py-spy/pull/104)

Cargo.toml

@@ -11,7 +11,7 @@ license = "GPL-3.0"
 build="build.rs"
 
 [dependencies]
-clap = "2"
+clap = {version="2", features=["wrap_help"]}
 console = "0.7"
 ctrlc = "3"
 indicatif = "0.11"
@@ -28,6 +28,9 @@ tempfile = "3.0.3"
 proc-maps = "0.1.6"
 memmap = "0.7.0"
 cpp_demangle = "0.2.12"
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "1.0"
 rand = "0.6"
 remoteprocess = {path="./remoteprocess", version="0.1.0"}
 

README.md

@@ -204,7 +204,7 @@ Not yet =).
 ## Credits
 
 py-spy is heavily inspired by [Julia Evans](https://github.com/jvns/) excellent work on [rbspy](http://github.com/rbspy/rbspy).
-In particular, the code to generate the flamegraphs is taken directly from rbspy, and this project uses the
+In particular, the code to generate flamegraph and speedscope files is taken directly from rbspy, and this project uses the
 [read-process-memory](https://github.com/luser/read-process-memory) and [proc-maps](https://github.com/benfred/proc-maps) crates that were spun off from rbspy.
 
 ## License

examples/native_stress_test.rs

@@ -33,7 +33,6 @@ fn native_stress_test(pid: remoteprocess::Pid) -> Result<(), failure::Error> {
            }
         }
     }
-    Ok(())
 }