nbdkit-indexed-gzip-filter(1)

NAME
nbdkit-indexed-gzip-filter - access .gz contents efficiently

SYNOPSIS
 nbdkit --filter=indexed-gzip PLUGIN gzip-index-path=PATH
                                     [gzip-index-span=SIZE]

DESCRIPTION
"nbdkit-indexed-gzip-filter" is a filter for nbdkit that provides fast and efficient random-access to gzip-compressed data.

The standard nbdkit-gzip-filter(1) decompresses the entire archive to a temporary file, which means you need to have enough storage or memory to store the complete uncompressed input.

With this filter, the entire archive still needs to be decompressed once, but only an index file needs to be stored in storage or memory, which (depending on user-specified distance between index points) may be 0.3% to 3% of the size of the uncompressed archive.

PARAMETERS

gzip-index-path=PATH
    Path to the complete gzip index file (created if it doesn't exist, reused if it does).

    This parameter is required.

gzip-index-span=SIZE
    Number of bytes between index points. Eg. 1M, 10M etc. (default: 1MB)

    A span of 10M produces an index file of eg, ~0.3% of uncompressed input

    A span of 1M produces an index file of eg, ~3% of uncompressed input.

    Smaller span improves random-access performance, since on average it means fewer bytes to decompress until reaching the requested byte (with the trade-off of a larger index file).

FILES

$filterdir/nbdkit-indexed-gzip-filter.so
    The filter.

    Use "nbdkit --dump-config" to find the location of $filterdir.

VERSION
nbdkit-indexed-gzip-filter first appeared in nbdkit 1.46.

SEE ALSO
nbdkit(1), nbdkit-filter(3), nbdkit-gzip-filter(1)

AUTHORS
Shasheen Ediriweera

Mark Adler

COPYRIGHT
Copyright (C) 2025 Shasheen Ediriweera

Copyright (C) 2005, 2012, 2018, 2023, 2024 Mark Adler

LICENSE
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

•   Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

•   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

•   Neither the name of Red Hat nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

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