Hello Roger,
On 24/08/21 8:14 pm, Roger Riggs wrote:
Hi Jaikiran,
Thanks for taking this on and getting it started.
One use case of canonical storage is repeatable builds.
It would be useful to identify the uses in the JDK that would need to
be changed to use the new function.
Surprisingly, the usage of the current "store" APIs within the JDK
appears to be very minimal. I'm hoping I didn't miss them, but from what
I see the Properties.store(...) which takes the Writer as a param isn't
used in anywhere within source of the JDK. The Properties.store(...)
which takes an OutputStream as a parameter gets used in the following
few places:
1. jdk.internal.vm.VMSupport#serializePropertiesToByteArray - Looking at
the implementation in this method and as the name suggests, the
Properties is being written out a byte array. This method gets called
from native code, from what I can see. I'll need a bit of help on this
one to understand whether that usage in the native code would benefit
from switching to the new API (when it is introduced) for
reproducibility when it comes to this call in
VMSupport#serializePropertiesToByteArray.
2. sun.net.www.MimeTable#saveAsProperties - This is a "protected" method
and from what I could see, doesn't get called anywhere in the JDK code.
Furthermore, This class resides in an internal package (sun.net.www) and
although it implements the public java.net.FileNameMap interface, the
"saveAsProperties" isn't a method exposed on that interface. So I think
this existing code/method wouldn't need to be updated to use the new API.
3. sun.font.FcFontConfiguration#writeFcInfo - This method writes out a
"cache file" which appears to be an internal implementation detail of
the FcFontConfiguration. More specifically, the contents of this file
apparently is "JDK Font Configuration", going by the comment it adds to
that file. This file gets written out to the "user.home" directory and
as far as I can see it, is only used/relevant to this
FcFontConfiguration. In context of reproducibility and the new API, I
think using that new API here could have a potential benefit of
reproducibility on the same system. However, someone with more
experience of this code would have to review if at all this
reproducibility is desirable.
These are the only references I could find in the JDK code (I didn't
include test cases).
One thing I do remember is the JDK build (through the make files) would
have certain Java code it would call to do some build steps. Is there a
easy way to find all such build related Java files within the JDK? I
would like to see if there are any references/calls to this method from
those build files. I am doing some searches myself, but knowing where to
search will give me more confidence that I haven't missed out any.
-Jaikiran
