RFR: 8276400: openjdk image Jars, Zips and Jmods built from the same source are not reproducible

[Michael Bien]

On Thu, 4 Nov 2021 20:56:45 GMT, Andrew Leonard <aleonard at openjdk.org> wrote:

> This PR enables reproducible Jars, Jmods and openjdk image zip files (eg.src.zip).
> It provides support for SOURCE_DATE_EPOCH for Jar, Jmod and underlying ZipOutputStream's.
> It fixes the following keys issues relating to reproducibility:
> - Jar and ZipOutputStream are not SOURCE_DATE_EPOCH aware
>   - Jar and ZipOutputStream now detect SOURCE_DATE_EPOCH environment setting
> - Jar and Jmod file content ordering was non-determinsitic
>   - Fixes to Jar and Jmod main's to ensure sorted classes content ordering
> - openjdk image zip file generation used "zip" which is non-determinsitic
>   - New openjdk build tool "GenerateZip" which produces the final determinsitic zip files as part of the build and also detects SOURCE_DATE_EPOCH
> 
> Signed-off-by: Andrew Leonard <anleonar at redhat.com>

a few minor comments

make/jdk/src/classes/build/tools/generatezip/GenerateZip.java line 96:

> 94:                     ok = createOk;
> 95:                 }
> 96:                 out.close();

could be a try-with-resource block

make/jdk/src/classes/build/tools/generatezip/GenerateZip.java line 191:

> 189:         Iterator<Map.Entry<String, Path>> itr = filesToProcess.entrySet().iterator();
> 190:         while(itr.hasNext()) {
> 191:             Map.Entry<String, Path> entry = itr.next();

could be `for (Map.Entry<String, Path> entry : filesToProcess.entrySet())`

make/jdk/src/classes/build/tools/generatezip/GenerateZip.java line 262:

> 260:                 zos.write(buf, 0, len);
> 261:             }
> 262:             is.close();

try-with-resource candidate + in.transferTo(zos)

make/jdk/src/classes/build/tools/generatezip/GenerateZip.java line 291:

> 289:             newArgs.add(arg);
> 290:         }
> 291:         return newArgs.toArray(new String[newArgs.size()]);

something might be missing here. It just adds args to a list and makes it an array again + If the language level allows it toArray(String[]::new) could be used.

src/java.base/share/classes/java/util/zip/ZipOutputStream.java line 106:

> 104:                         value = -1;
> 105:                     }
> 106:                     return new Long(value);

value can be returned here directly which will use auto-boxing. (new Long(long) is deprecated).

src/jdk.jlink/share/classes/jdk/tools/jmod/JmodTask.java line 799:

> 797:             Iterator<Map.Entry<String, Path>> itr = filesToProcess.entrySet().iterator();
> 798:             while(itr.hasNext()) {
> 799:                 Map.Entry<String, Path> entry = itr.next();

another for-each candidate

test/jdk/java/util/zip/ZipSourceDateEpoch.java line 71:

> 69:             zos.close();
> 70:             os.close();
> 71:         }

try-with-resource

test/jdk/java/util/zip/ZipSourceDateEpoch.java line 97:

> 95:             zis.close();
> 96:             fis.close();
> 97:         }

try-with-resource

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PR: https://git.openjdk.java.net/jdk/pull/6268