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lib/DBIx/BatchChunker.pm  view on Meta::CPAN

package DBIx::BatchChunker;

our $AUTHORITY = 'cpan:GSG';
# ABSTRACT: Run large database changes safely
use version;
our $VERSION = 'v1.0.2'; # VERSION

use Moo;
use MooX::StrictConstructor;

use CLDR::Number;

use Types::Standard        qw( Str Bool Undef ArrayRef HashRef CodeRef InstanceOf Tuple Maybe Optional slurpy );
use Types::Numbers         qw( NumRange UnsignedInt PerlSafeInt PositiveInt PositiveOrZeroNum );
use Type::Utils;

use List::Util        1.33 (qw( min max sum any first ));  # has any/all/etc.
use Math::BigInt upgrade => 'Math::BigFloat';
use Math::BigFloat;
use POSIX                   qw( ceil );
use Scalar::Util            qw( blessed weaken );
use Term::ProgressBar 2.14;                          # with silent option
use Time::HiRes             qw( time sleep );

use DBIx::BatchChunker::LoopState;

# Don't export the above, but don't conflict with StrictConstructor, either
use namespace::clean -except => [qw< new meta >];

# This is now an unused, dummy variable
our $DB_MAX_ID = ~0;

#pod =encoding utf8
#pod
#pod =head1 SYNOPSIS
#pod
#pod     use DBIx::BatchChunker;
#pod
#pod     my $account_rs = $schema->resultset('Account')->search({
#pod         account_type => 'deprecated',
#pod     });
#pod
#pod     my %params = (
#pod         chunk_size  => 5000,
#pod         target_time => 5,
#pod
#pod         rs      => $account_rs,
#pod         id_name => 'account_id',
#pod
#pod         coderef => sub { $_[1]->delete },
#pod         sleep   => 1,
#pod         verbose => 1,
#pod
#pod         progress_name    => 'Deleting deprecated accounts',
#pod         process_past_max => 1,
#pod     );
#pod
#pod     # EITHER:
#pod     # 1) Automatically construct and execute the changes:
#pod
#pod     DBIx::BatchChunker->construct_and_execute(%params);
#pod
#pod     # OR
#pod     # 2) Manually construct and execute the changes:
#pod
#pod     my $batch_chunker = DBIx::BatchChunker->new(%params);
#pod
#pod     $batch_chunker->calculate_ranges;
#pod     $batch_chunker->execute;
#pod
#pod =head1 DESCRIPTION
#pod
#pod This utility class is for running a large batch of DB changes in a manner that doesn't
#pod cause huge locks, outages, and missed transactions.  It's highly flexible to allow for
#pod many different kinds of change operations, and dynamically adjusts chunks to its
#pod workload.
#pod
#pod It works by splitting up DB operations into smaller chunks within a loop.  These chunks
#pod are transactionalized, either naturally as single-operation bulk work or by the loop
#pod itself.  The full range is calculated beforehand to get the right start/end points.
#pod A L<progress bar|/Progress Bar Attributes> will be created to let the deployer know the