UID2-7105: parse salt files line-by-line to avoid String[] buffer#618
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mcollins-ttd wants to merge 1 commit into
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UID2-7105: parse salt files line-by-line to avoid String[] buffer#618mcollins-ttd wants to merge 1 commit into
mcollins-ttd wants to merge 1 commit into
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Replace reader.lines().toArray(String[]::new) in readInputStream with a
streaming BufferedReader approach via a new SaltFileParser.parseLines method.
Eliminates the ~147 MB intermediate String[] allocated per snapshot load.
EncryptedRotatingSaltProvider also updated to use parseLines via StringReader,
avoiding the split("\n") allocation in the old parseFile path.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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Why
RotatingSaltProvider.readInputStreamcalledreader.lines().toArray(String[]::new)before parsing, which materialised the entire salt file as aString[]of ~1M objects. For a 99 MB snapshot this creates ~147 MB of temporary strings on the heap simultaneously with the ~180 MBSaltEntry[]being built — a ~327 MB peak per snapshot load that is pure overhead.EncryptedRotatingSaltProviderhad a related issue: it calledsaltFileParser.parseFile(decrypted, size)which internally callsString.split("\n"), creating another largeString[]from the already-decrypted string.What changed
SaltFileParser.parseLines(BufferedReader, Integer)— reads line-by-line from the reader, parsing directly into a pre-sizedSaltEntry[]with no intermediate array.RotatingSaltProvider.readInputStreamnow callsparseLinesdirectly instead oftoArray+parseFileLines.EncryptedRotatingSaltProvider.readInputStreamwraps the decrypted string in aStringReader/BufferedReaderand callsparseLines, avoiding thesplit("\n")allocation.parseFile/parseFileLinesmethods are unchanged (other callers unaffected).Memory impact
Per snapshot load: peak drops from ~327 MB to ~180 MB (the
SaltEntry[]itself, which is irreducible). With 2 snapshots, worst-case overlap drops from ~507 MB to ~360 MB.Testing
SaltFileParserTest.parseLinesMatchesParseFileto verifyparseLinesproduces identical output toparseFilefor the same input.SaltFileParserTest,RotatingSaltProviderTest, andEncryptedRotatingSaltProviderTesttests pass (13 total, 0 failures).Part of UID2-7105.
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