/ 
DarkPAN-Indexer-1.0.2
/ DarkPAN::Indexer

NAME

DarkPAN::Indexer - build and maintain a multi-version index of a DarkPAN

SYNOPSIS

use DarkPAN::Indexer;

my $indexer = DarkPAN::Indexer->new( config_file => '/path/to/darkpan.json' );

# full build from every distribution in the repository
my $stats = $indexer->create_index;

# incrementally (re)index a single distribution
$indexer->update_index( distribution => 'authors/id/A/AB/AUTHOR/Foo-1.0.tar.gz' );

# remove a distribution's packages from the index
$indexer->delete_from_index( distribution => 'authors/id/A/AB/AUTHOR/Foo-1.0.tar.gz' );

DESCRIPTION

DarkPAN::Indexer builds and maintains a multi-version package index for a DarkPAN. Unlike 02packages.details.txt.gz, which records only the latest version of each package, this index records every version of every package present in the repository, so a client can resolve and install a specific historical version by name -- not just the latest.

The indexer is an orchestrator. It composes two pluggable pieces and moves opaque data between them:

  • A storage engine ("STORAGE ENGINES") -- where the distributions and the index physically live (S3, local filesystem, ...).

  • A format engine ("FORMAT ENGINES") -- how the index is built and queried (SQLite, ...).

The orchestrator itself knows nothing about S3 or SQLite. It reads config, constructs the two engines named there, and drives them. This is what lets the same code index an S3-backed DarkPAN behind CloudFront and a plain directory of tarballs on a laptop.

CONSTRUCTOR

new

my $indexer = DarkPAN::Indexer->new( config_file => $path ); my $indexer = DarkPAN::Indexer->new( config => \%config );

Constructs an indexer. Provide either config_file (a path to a JSON config, see "CONFIGURATION") or config (an already-loaded config hashref). The storage and format engines are constructed immediately from the config.

METHODS

create_index

my $stats = $indexer->create_index;

Builds a fresh index from every distribution in the repository. Enumerates the repository (storage->list_distributions), scans each distribution for the packages it provides, loads them into a new index, and publishes the index back to storage. This is the full-rebuild / authoritative operation; run it to create the index initially or to rebuild it from ground truth.

Returns a stats hashref (distributions seen, distributions indexed, failures, modules written).

update_index

$indexer->update_index( distribution => $key );

Incrementally (re)indexes a single distribution. Retrieves the current index, performs a delete-then-insert for the named distribution's packages, and publishes the updated index. $key is the storage key of the distribution tarball (e.g. authors/id/A/AB/AUTHOR/Foo-1.0.tar.gz). The whole read-modify-write is performed under a storage lock.

delete_from_index

$indexer->delete_from_index( distribution => $key );

Removes a single distribution's packages from the index. Retrieves the current index, deletes the rows for the named distribution, and publishes. Also performed under a storage lock.

CONFIGURATION

The config (JSON file via config_file, or a hashref via config) describes one DarkPAN. The keys the indexer reads are:

storage

Selects and configures the storage engine, e.g.:

"storage" : { "type" : "S3", "bucket" : "my-darkpan", "region" : "us-east-1" }
"storage" : { "type" : "Filesystem", "root" : "/srv/darkpan" }

type names the engine (resolved to DarkPAN::Indexer::Storage::<type>, or a +Fully::Qualified name). For backward compatibility, a config with a legacy AWS block and no storage block is treated as S3.

format

Selects the index format engine, e.g. "format" : { "type" : "SQLite" }. Defaults to SQLite if omitted.

packages_version_index

The storage key of the published index, e.g. orepan2/modules/packages.db.gz. A .gz suffix causes the index to be stored compressed.

STORAGE ENGINES

A storage engine consumes the DarkPAN::Indexer::Storage role and provides: list_distributions, fetch_object, save_object, has_object, lock, and base_url, plus the role-provided retrieve_index/publish_index. DarkPAN::Indexer::Storage::S3 and DarkPAN::Indexer::Storage::Filesystem ship with this distribution.

FORMAT ENGINES

A format engine consumes the DarkPAN::Indexer::Format role and provides: create_index, update_index, load_index, and delete_from_index. The role provides the shared index_distribution (tarball -> package records) machinery. DarkPAN::Indexer::Format::SQLite ships with this distribution.

SEE ALSO

DarkPAN::Indexer::CLI, DarkPAN::Resolver::SQLite, OrePAN2::Lite

AUTHOR

Rob Lauer - <rlauer@treasurersbriefcase.com>