Package com.ljarocki.parallelzip.internal

Class ParallelZipWriter

java.lang.Object

com.ljarocki.parallelzip.internal.ParallelZipWriter

public final class ParallelZipWriter
extends Object

Core parallel ZIP writer. Stateless and reusable; both the directory front-end (write(java.util.List<com.ljarocki.parallelzip.internal.ParallelZipWriter.Source>, java.nio.file.Path, boolean, int, int, boolean)) and the Gradle CopyAction feed it a list of ParallelZipWriter.Entry.

Pipeline: every entry is compressed (STORE or DEFLATE) on a worker pool, while a single writer thread drains results in the given list order and streams them to the archive. Parallelism never affects the byte layout, so output is deterministic regardless of thread count. With fixed timestamps the archive is byte-for-byte reproducible across rebuilds of identical content.

Small entries are compressed in memory; entries larger than SPILL_THRESHOLD are mapped straight from the source file into the native accelerator (see MMAP_THRESHOLD) when one is available, or otherwise streamed through the JDK deflater to a temp file, so a single entry may be arbitrarily large either way. ZIP64 is emitted automatically for archives > 4 GiB, more than 65,535 entries, or per-entry sizes/offsets beyond 4 GiB.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	ParallelZipWriter.Entry	One archive entry.
static final record	ParallelZipWriter.Result
static final class	ParallelZipWriter.Sink	A running compress-and-write pipeline.
static final record	ParallelZipWriter.Source	A source tree to be added under an optional archive path prefix (directory front-end).

Field Summary

Fields

Modifier and Type	Field	Description
static final int	FIXED_DOS_DATE
static final int	FIXED_DOS_TIME
static final long	SPILL_THRESHOLD	Entries larger than this are streamed (spilled) instead of held in memory.

Method Summary

Modifier and Type	Method	Description
static ParallelZipWriter.Entry	dirEntry(String name, int dosTime, int dosDate, int externalAttr)
static int[]	dosDateTime(long millis)
static ParallelZipWriter.Entry	fileEntry(String name, Path file, boolean fileIsTemp, long size, int dosTime, int dosDate, int externalAttr)
static ParallelZipWriter.Entry	inlineEntry(String name, byte[] data, int dosTime, int dosDate, int externalAttr)
static ParallelZipWriter.Result	write(List<ParallelZipWriter.Source> sources, Path out, boolean store, int level, int threads, boolean preserveTimestamps)	Directory front-end: walk source trees and archive them.
static ParallelZipWriter.Result	writeEntries(List<ParallelZipWriter.Entry> entries, Path out, boolean store, boolean skipAlreadyCompressed, int level, int threads, boolean forceZip64, long spillThreshold, Path spillDir)
static ParallelZipWriter.Result	writeEntries(List<ParallelZipWriter.Entry> entries, Path out, boolean store, int level, int threads, boolean forceZip64, long spillThreshold, Path spillDir)	Core: compress entries in parallel and write them to out in list order.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

SPILL_THRESHOLD

public static final long SPILL_THRESHOLD

Entries larger than this are streamed (spilled) instead of held in memory.

See Also:

• Constant Field Values

FIXED_DOS_TIME

public static final int FIXED_DOS_TIME

See Also:

• Constant Field Values

FIXED_DOS_DATE

public static final int FIXED_DOS_DATE

See Also:

• Constant Field Values

Method Details

dirEntry

public static ParallelZipWriter.Entry dirEntry(String name,
 int dosTime,
 int dosDate,
 int externalAttr)

fileEntry

public static ParallelZipWriter.Entry fileEntry(String name,
 Path file,
 boolean fileIsTemp,
 long size,
 int dosTime,
 int dosDate,
 int externalAttr)

inlineEntry

public static ParallelZipWriter.Entry inlineEntry(String name,
 byte[] data,
 int dosTime,
 int dosDate,
 int externalAttr)

write

public static ParallelZipWriter.Result write(List<ParallelZipWriter.Source> sources,
 Path out,
 boolean store,
 int level,
 int threads,
 boolean preserveTimestamps)
                                      throws IOException,
InterruptedException

Directory front-end: walk source trees and archive them. Used by tests and the simple API.

Throws:

IOException

InterruptedException

writeEntries

public static ParallelZipWriter.Result writeEntries(List<ParallelZipWriter.Entry> entries,
 Path out,
 boolean store,
 int level,
 int threads,
 boolean forceZip64,
 long spillThreshold,
 Path spillDir)
                                             throws IOException,
InterruptedException

Core: compress entries in parallel and write them to out in list order. The caller owns spillDir (creation and cleanup).

Throws:

IOException

InterruptedException

writeEntries

public static ParallelZipWriter.Result writeEntries(List<ParallelZipWriter.Entry> entries,
 Path out,
 boolean store,
 boolean skipAlreadyCompressed,
 int level,
 int threads,
 boolean forceZip64,
 long spillThreshold,
 Path spillDir)
                                             throws IOException,
InterruptedException

Throws:

IOException

InterruptedException

dosDateTime

public static int[] dosDateTime(long millis)