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<font face="monospace" size="4">It sounds like you are asking two
questions. At the API level, you are asking whether adding a
Classfile.parse(ByteBuffer) method would be in scope. But at the
implementation level, you are asking whether we would be OK to
make ByteBuffer *the primitive* on which processing the byte[]
format is based, which is a more intrusive change. <br>
<br>
My first reaction is that the first seems fine in theory, but if
the only reasonable implementation strategy is the latter, then I
am pretty skeptical. <br>
<br>
A ByteBuffer-accepting factory that simply copied to a byte[]
would be fine (this is what we do with the existing Path-accepting
factory, it's a similar form of convenience), but it sounds like
this would not make you any happier.<br>
<br>
</font><br>
<div class="moz-cite-prefix">On 3/10/2025 1:38 PM, David Lloyd
wrote:<br>
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<blockquote type="cite" cite="mid:CANghgrQf44YJ0tux4QVpL0HU2aKoQhdh17kAsQ6JHW6-sV5__g@mail.gmail.com">
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif">When defining
a class in the JDK, one may either use a byte array or a
byte buffer to hold the contents of the class. The latter is
useful when (for example) a JAR file containing uncompressed
classes is mapped into memory. Thus, some class loaders
depend on this form of the API for class definition.</div>
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif">If I were to
supplement such a class loader with a class transformation
step based on the class file API, I would have to copy the
bytes of each class on to the heap as a byte[] before I
could begin parsing it. This is potentially expensive, and
definitely awkward.</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br>
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif">After
transformation, it doesn't really matter if you have a
byte[] or ByteBuffer because either way, the class can be
defined directly.</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif">It would be
nice if the class file parser could accept either a byte[]
or a ByteBuffer. I did a quick bit of exploratory work and
it looks like porting the code to read from a ByteBuffer
instead of a byte[] (using ByteBuffer.wrap() for the array
case) would be largely straightforward *except* for the code
which parses UTF-8 constants into strings. Also there could
be some small performance differences (maybe positive, maybe
negative) depending on how the buffer is accessed.</div>
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br>
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Is this
something that might be considered?</div>
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br>
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<span class="gmail_signature_prefix">-- </span><br>
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<div dir="ltr">- DML • he/him<br>
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