Remove unused SHA-1 hash from UNPACK markers #46520
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In BootZipCopyAction and AbstractJarWriter, SHA-1 hash is calculated for stored entries requiring unpack and set as entry comment. However, the hash isn't used anywhere, just the marker prefix 'UNPACK:' is checked. This commit removes the unnecessary SHA-1 hash calculation which reads the file completely in memory, potentially three times in extreme cases. Now the comment is simply set to 'UNPACK:' without any hash, improving performance. Fixes spring-projectsgh-46183 Signed-off-by: Hyunjoon Choi <hyunjoon@example.com> Signed-off-by: academey <academey@gmail.com>
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We should probably update the runtime side of things as well: The @academey please don't make any changes to the PR just yet, I'd like to discuss with the team first. |
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We discussed this today and want to use |
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In BootZipCopyAction and AbstractJarWriter, SHA-1 hash is calculated for stored entries requiring unpack and set as entry comment. However, the hash isn't used anywhere, just the marker prefix 'UNPACK:' is checked. This commit removes the unnecessary SHA-1 hash calculation which reads the file completely in memory, potentially three times in extreme cases. Now the comment is simply set to 'UNPACK:' without any hash, improving performance. See gh-46520 Signed-off-by: Hyunjoon Choi <hyunjoon@example.com> Signed-off-by: academey <academey@gmail.com>
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Thanks very much for the PR, @academey. |
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This PR removes the unused SHA-1 hash calculation from UNPACK markers in the JAR/WAR packaging process.
Current behavior:
When creating executable JARs/WARs, Spring Boot calculates a SHA-1 hash for entries that require unpacking and appends it to the entry comment as
UNPACK:<hash>. However, this hash is never used - only theUNPACK:prefix is checked.Changes made:
StoredEntryPreparatorin bothBootZipCopyActionandAbstractJarWriterUNPACK:<sha1-hash>to simplyUNPACK:Performance improvement:
This eliminates unnecessary file reads during packaging. Previously, files could be read up to 3 times (CRC calculation, SHA-1 hash, and actual copying). Removing the hash calculation reduces I/O operations and memory usage, especially beneficial for large libraries.
Fixes #46183