Re: RFR: 8256156: JFR: Allow 'jfr' tool to show metadata without a recording

[Yang Yi]

Happy New Year.

Can anyone help reviewing this patch? ;)

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PR: https://git.openjdk.java.net/jdk/pull/1904


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From:Yang Yi <github.com+5010047+kelthuzadx at openjdk.java.net>
Send Time:2021 Jan. 5 (Tue.) 10:55
To:hotspot-jfr-dev <hotspot-jfr-dev at openjdk.java.net>
Subject:RFR: 8256156: JFR: Allow 'jfr' tool to show metadata without a recording

Hi all,

May I please have a review for this minor patch?

It simplifies the use of subcommand `metadata` of jfr tool. Recording 
file is no longer mandatory, users can directly use `jfr metadata` to 
output JDK builtin meta information. As JDK-8256156 mentioned, it also 
supports events and categories filters:
$ jfr metadata 
$ jfr metadata recording.jfr # compatible
$ jfr metadata --events jdk.ThreadStart,jdk.ThreadEnd
$ jfr metadata --events jdk.ThreadStart,jdk.ThreadEnd recording.jfr
$ jfr metadata --categories GC,Detailed
$ jfr metadata --categories GC,Detailed recording.jfr

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Commit messages:
 - Allow jfr tool to show metadata without a recording

Changes: https://git.openjdk.java.net/jdk/pull/1904/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1904&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256156
  Stats: 151 lines in 5 files changed: 131 ins; 8 del; 12 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1904.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1904/head:pull/1904

PR: https://git.openjdk.java.net/jdk/pull/1904