Append random id to log files so they get ignored during git-diff

[kunalspathak]

Today, when doing diff, we perform git diff on base and diff. These folders has .dasm as well as .log files. The .log files are comparable in size. For e.g., they are 520MB while .dasm files are 800MB. Once we do git diff, we then filter the diffs that are coming out of .dasm files. Thus, we unnecessarily spend time diffing the .log files. In #284, I added a way to ignore files if they are not present in both the folders. With that, I propose to add a random ID to the log files so they automatically get ignored when doing git diff and thus saving some time.

[kunalspathak]

@dotnet/jit-contrib

[CarolEidt]

Looks like a reasonable approach to me.

[BruceForstall]

Seems like kind of a hack.

Is git diff recursive? If not (or we can invoke it to not recurse), could we put the log files in a log subdirectory? E.g., base\log\xxx.log, diff\log\xxx.log?

[kunalspathak]

Seems like kind of a hack.

If not (or we can invoke it to not recurse), could we put the log files in a log subdirectory? E.g., base\log\xxx.log, diff\log\xxx.log?

I agree. Better way is to just create separate logs folder for base and diff. With that, it will create 2 new folders baselogs and difflogs that will contain log files. So when diffing, git diff diff base should just work fine.

dasmset_62 |-- base |-- diff |-- baselogs |-- difflogs 

Is git diff recursive?

git diff --no-index has limitation because it is done on non repo. If git diff is done on repo, we can do file filtering, recursive, etc.

[BruceForstall]

LGTM

Looks from the code like you've gone with something closer to my suggestion, namely:

dasmset_62 |-- base |-- logs |-- diff |-- logs 

The title of this PR is now inaccurate.

[AndyAyersMS]

For more complex structures the diff / base output may be directory trees (eg if you run jit-diff on the test tree). What happens then?

You can test this by just creating a small directory tree and placing some test apps in the leaves and then using --assembly to point at the root of the tree.

[kunalspathak]

Here is how it produces with my latest change. It is not very pleasant...Do you want me to find the common ancestor and create log folders in that?

binaries folder:

binaries |--- 1 |--- foo.dll |--- 2 |--- bar.dll |--- 3 |--- baz.dll |--- projs.dll 

Output:

dasmset_63 |--- base |--- projs.dasm |--- 1 |--- foo.dasm |--- 1log |--- foo.log |--- 2 |--- bar.dasm |--- 2log |--- bar.log |--- 3 |--- baz.dasm |--- 3log |--- baz.log |--- projs.dasm |---baselog |---projs.log |--- diff |--- projs.dasm |--- 1 |--- foo.dasm |--- 1log |--- foo.log |--- 2 |--- bar.dasm |--- 2log |--- bar.log |--- 3 |--- baz.dasm |--- 3log |--- baz.log |--- projs.dasm |---difflog |---projs.log 

[BruceForstall]

Everything goes under a _rootPath, which is a user-specified argument, so you have to put everything in that path.

You could create a new _logsRootPath argument (e.g., "--logsOutputPath") and put everything in a tree under that. If passed the same directory as _rootPath, behavior would be the same as today. Or, if passed something different, the logs are separated. You would have to pass this additional argument in from jit-diff. It could default to the same as _rootPath.