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Direktori : /home/opti/optisoftcom-new/perl/usr/lib/perl5/MongoDB/Op/ |
Current File : /home/opti/optisoftcom-new/perl/usr/lib/perl5/MongoDB/Op/_Explain.pm |
# Copyright 2015 - present MongoDB, Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. use strict; use warnings; package MongoDB::Op::_Explain; # Encapsulate code path for explain commands/queries use version; our $VERSION = 'v2.0.2'; use Moo; use MongoDB::Op::_Command; use Types::Standard qw( InstanceOf ); use Tie::IxHash; use boolean; use namespace::clean; has query => ( is => 'ro', required => 1, isa => InstanceOf['MongoDB::Op::_Query'], ); with $_ for qw( MongoDB::Role::_PrivateConstructor MongoDB::Role::_CollectionOp MongoDB::Role::_ReadOp ); sub execute { my ( $self, $link, $topology ) = @_; my $res = $link->supports_explain_command ? $self->_command_explain( $link, $topology ) : $self->_legacy_explain( $link, $topology ); return $res; } sub _command_explain { my ( $self, $link, $topology ) = @_; my $cmd = Tie::IxHash->new( @{ $self->query->_as_command } ); # XXX need to standardize error here if ($self->query->has_hint) { # cannot use hint on explain, throw error MongoDB::Error->throw( message => "cannot use 'hint' with 'explain'", ); } my $op = MongoDB::Op::_Command->_new( db_name => $self->db_name, query => [ explain => $cmd, @{ $self->read_concern->as_args( $self->session ) } ], query_flags => {}, read_preference => $self->read_preference, bson_codec => $self->bson_codec, session => $self->session, monitoring_callback => $self->monitoring_callback, ); my $res = $op->execute( $link, $topology ); return $res->{output}; } sub _legacy_explain { my ( $self, $link, $topology ) = @_; my $orig_query = $self->query; my $cloned_opts = { %{ $orig_query->options } }; $cloned_opts->{explain} = 1; # per David Storch, drivers *must* send a negative limit to instruct # the query planner analysis module to add a LIMIT stage. For older # explain implementations, it also ensures a cursor isn't left open. $cloned_opts->{limit} = ( -1 * abs( $cloned_opts->{limit} ) ); my $new_query = MongoDB::Op::_Query->_new( %$orig_query, # override options from original options => $cloned_opts ); return $new_query->execute( $link, $topology )->next; } 1;