discourse-legacysite-perl/site/slowtwitch.com/cgi-bin/articles/GT/SQL/Search/INTERNAL/Indexer.pm
2024-06-17 21:49:12 +10:00

412 lines
14 KiB
Perl

# ====================================================================
# Gossamer Threads Module Library - http://gossamer-threads.com/
#
# GT::SQL::Search::INTERNAL::Indexer
# Author: Aki Mimoto
# CVS Info : 087,071,086,086,085
# $Id: Indexer.pm,v 1.11 2004/01/13 01:35:19 jagerman Exp $
#
# Copyright (c) 2004 Gossamer Threads Inc. All Rights Reserved.
# ====================================================================
#
package GT::SQL::Search::INTERNAL::Indexer;
# ------------------------------------------------------------------------------
# Preamble information related to the object
use strict;
use vars qw/@ISA $ATTRIBS $VERSION $DEBUG /;
use GT::SQL::Search::Base::Indexer;
@ISA = qw/ GT::SQL::Search::Base::Indexer /;
$DEBUG = 0;
$VERSION = sprintf "%d.%03d", q$Revision: 1.11 $ =~ /(\d+)\.(\d+)/;
sub load {
shift;
return GT::SQL::Search::INTERNAL::Indexer->new(@_)
}
sub drop_search_driver {
# ------------------------------------------------------------------------------
my $self = shift;
my $table = $self->{table}->name;
my $rc1 = $self->{table}->do_query(qq!DROP TABLE $table! ."_Word_List");
my $rc2 = $self->{table}->do_query(qq!DROP TABLE $table! ."_Score_List");
return 1;
}
sub add_search_driver {
# ------------------------------------------------------------------------------
my $self = shift;
my $name = $self->{table}->name;
# first create the table that handles the words.
my $creator = $self->{table}->creator ( $name . "_Word_List" );
$creator->cols(
Word_ID => {
pos => 1,
type => 'int',
not_null => 1,
unsigned => 1
},
Word => {
pos => 2,
type => 'varchar',
not_null=> 1,
size => '50'
},
Frequency => {
pos => 3,
type => 'int',
not_null=> 1
}
);
$creator->pk('Word_ID');
$creator->ai('Word_ID');
$creator->unique({ $name . "_wordndx" => ['Word'] });
$creator->create('force') or return;
# now create the handler for scores
$creator = $self->{table}->creator( $name . '_Score_List' );
$creator->cols(
Word_ID => {
pos => 1,
type => 'int',
not_null => 1,
unsigned => 1
},
Item_ID => {
pos => 2,
type => 'int',
not_null => 1,
unsigned => 1
},
Score => {
pos => 3,
type => 'int',
not_null => 1
},
Word_Pos => {
pos => 4,
type => 'int',
not_null => 1
}
);
$creator->index({ 'wndx' => ['Word_ID', 'Item_ID', 'Score'], 'itndx' => ['Item_ID'] });
$creator->create('force') or return;
return 1;
}
sub post_create_table {
# ------------------------------------------------------------------------------
# creates the index tables..
#
return $_[0]->add_search_driver(@_);
}
sub post_drop_table {
# -------------------------------------------------------
# Remove the index tables.
#
return $_[0]->drop_search_driver(@_);
}
sub init_queries {
# -------------------------------------------------------
# Pre-load all our queries.
#
my $self = shift;
my $queries = shift;
my $driver = $self->{table}->{driver} or return $self->error ('NODRIVER', 'FATAL');
my $table_name = $self->{table}->name() or return $self->error('NOSCHEMA', 'FATAL');
my $wtable = $table_name . '_Word_List';
my $seq = $wtable . '_seq';
my $stable = $table_name . '_Score_List';
my %ai_queries = (
ins_word_ORACLE => "INSERT INTO $wtable (Word_ID, Word, Frequency) VALUES ($seq.NEXTVAL, ?, ?)",
ins_word_PG => "INSERT INTO $wtable (Word_ID, Word, Frequency) VALUES (NEXTVAL('$seq'), ?, ?)",
ins_word => "INSERT INTO $wtable (Word, Frequency) VALUES (?, ?)"
);
my %queries = (
upd_word => "UPDATE $wtable SET Frequency = ? WHERE Word_ID = ?",
sel_word => "SELECT Word_ID,Word,Frequency FROM $wtable WHERE Word = ?",
sel_freq => "SELECT Frequency FROM $wtable WHERE Word_ID = ?",
del_word => "DELETE FROM $wtable WHERE Word_ID = ?",
mod_word => "UPDATE $wtable SET Frequency = Frequency - ? WHERE Word_ID = ?",
ins_scor => "INSERT INTO $stable (Word_ID, Item_ID, Score, Word_Pos) VALUES (?, ?, ?, ?)",
item_cnt => "SELECT Word_ID, COUNT(*) FROM $stable WHERE Item_ID = ? GROUP BY Word_ID",
scr_del => "DELETE FROM $stable WHERE Item_ID = ?",
dump_word => "DELETE FROM $wtable",
dump_scor => "DELETE FROM $stable"
);
my $type = uc $self->{table}->{connect}->{driver};
$self->{ins_word} = $driver->prepare($ai_queries{"ins_word_$type"} || $ai_queries{"ins_word"});
# check to see if the table exist
$self->{table}->new_table( $wtable ) or return $self->error('CANTPREPARE','WARN', 'Loading of table', $GT::SQL::error);
$self->{table}->new_table( $stable ) or return $self->error('CANTPREPARE','WARN', 'Loading of table', $GT::SQL::error);
if ($type eq 'MYSQL') {
foreach my $query (keys %queries) {
$self->{$query} = $driver->prepare_raw ($queries{$query}) or return $self->error ('CANTPREPARE', 'WARN', $query, $GT::SQL::error);
}
}
else {
foreach my $query (keys %queries) {
$self->{$query} = $driver->prepare ($queries{$query}) or return $self->error ('CANTPREPARE', 'WARN', $query, $GT::SQL::error);
}
}
}
sub post_add_record {
# -------------------------------------------------------
# indexes a single record
my ($self, $rec, $insert_sth ) = @_;
# Only continue if we have weights and a primary key.
my $tbl = $self->{table} or $self->error( 'NODRIVER', 'FATAL' );
my %weights = $tbl->_weight_cols() or return;
my ($pk) = $tbl->pk();
my $item_id = ( $tbl->ai() and $insert_sth ) ? $insert_sth->insert_id() : $rec->{$pk};
my $index = 0;
$self->{init} or $self->init_queries;
# Go through each column and index it.
foreach my $column ( keys %weights ) {
my ($word_list, $rejected) = $self->_tokenize( $rec->{$column} );
$word_list or next;
# Build a hash of word => frequency.
my %words;
foreach my $word (@{$word_list}) {
$words{$word}++;
}
# Add the words in, or update frequency.
my %word_ids = ();
while (my ($word, $freq) = each %words) {
$self->{sel_word}->execute($word) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
my $word_r = $self->{sel_word}->fetchrow_arrayref; # Word_ID, Word, Frequency
if ($word_r) {
$word_r->[2] += $freq;
$word_ids{$word} = $word_r->[0];
$self->{upd_word}->execute ($word_r->[2], $word_r->[0]) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
}
else {
$self->{ins_word}->execute ($word, $words{$word}) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
$word_ids{$word} = $self->{ins_word}->insert_id();
}
}
# now that we have the word ids, insert each of the word-points
my $weight = $weights{$column};
foreach my $word ( @{$word_list} ) {
$self->{ins_scor}->execute ($word_ids{$word}, $item_id, $weight, $index++) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
}
$index++;
}
return 1;
}
sub reindex_all {
# -------------------------------------------------------
my $self = shift;
my $table = shift;
my $opts = shift;
my $tick = $opts->{tick} || 0;
my $max = $opts->{max} || 5000;
my %weights = $self->{table}->_weight_cols() or return;
my @weight_list = keys %weights;
my @weight_arr = map { $weights{$_} } @weight_list;
my ($pk) = $self->{table}->pk();
my $index = 0;
my $word_id = 1;
$self->{init} or $self->init_queries;
# first nuke the current index
$self->dump_index();
# Go through the table and index each field.
my $iterations = 1;
my $count = 0;
while (1) {
if ($max) {
my $offset = ($iterations-1) * $max;
$table->select_options ( "LIMIT $offset,$max");
}
my $cond = $opts->{cond} || {};
my $sth = $table->select($cond, [ $pk, @weight_list] );
my $done = 1;
while ( my $arrayref = $sth->fetchrow_arrayref() ) {
# the primary key value
my $i = 0;
my $item_id = $arrayref->[($i++)];
$index = 0;
$done = 0;
# start going through the record data
foreach my $weight ( @weight_arr ) {
my ($word_list, $junk) = $self->_tokenize( $arrayref->[$i++] );
$word_list or next;
# Build a hash of word => frequency.
my %words;
foreach my $word (@{$word_list}) {
$words{$word}++;
}
# Add the words in, or update frequency.
my %word_ids = ();
while (my ($word, $freq) = each %words) {
$self->{sel_word}->execute($word) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
my $word_r = $self->{sel_word}->fetchrow_arrayref; # WordID,Word,Freq
if ($word_r) {
$word_r->[2] += $freq;
$word_ids{$word} = $word_r->[0];
$self->{upd_word}->execute ($word_r->[2], $word_r->[0]) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
}
else {
$self->{ins_word}->execute ($word, $words{$word}) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
$word_ids{$word} = $self->{ins_word}->insert_id();
}
}
# now that we have the word ids, insert each of the word-points
foreach my $word ( @{$word_list} ) {
$self->{ins_scor}->execute ($word_ids{$word}, $item_id, $weight, $index++) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
}
$index++;
}
if ($tick) {
$count++;
$count % $tick or (print "$count ");
$count % ($tick*10) or (print "\n");
}
}
return if ($done);
$iterations++;
return if (! $max);
}
}
sub pre_delete_record {
# -------------------------------------------------------
# Delete a records index values.
#
my $self = shift;
my $where = shift;
my $tbl = $self->{table} or $self->error( 'NODRIVER', 'FATAL' );
my %weights = $tbl->_weight_cols() or return;
my ($pk) = $tbl->pk();
my $q = $tbl->select( $where, [ $pk ] );
while ( my $aref = $q->fetchrow_arrayref() ) {
my $item_id = $aref->[0] or next;
my @weight_list = keys %weights;
my $index = 0;
$self->{init} or $self->init_queries;
# Get a frequency count for each word
$self->{item_cnt}->execute($item_id) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
# Now go through and either decrement the freq, or remove the entry.
while ( my ($word_id, $frequency) = $self->{item_cnt}->fetchrow_array() ) {
$self->{sel_freq}->execute($word_id) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
$self->debug( "Deleting frequencies for $word_id. decreasing by $frequency" ) if ($self->{_debug});
if (my $freq = $self->{sel_freq}->fetchrow_arrayref) {
if ($freq->[0] == $frequency) {
$self->{del_word}->execute($word_id) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
}
else {
$self->{mod_word}->execute($frequency, $word_id) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
}
}
}
# Remove the listings from the scores table.
$self->{scr_del}->execute($item_id) or return $self->error ('CANTEXECUTE', 'WARN', $DBI::errstr);
}
return 1;
}
sub post_update_record {
# -------------------------------------------------------
my ( $self, $set_cond, $where_cond, $tmp ) = @_;
# delete the previous record
$self->pre_delete_record( $where_cond ) or return;
#
# the new record
my $tbl = $self->{table} or $self->error( 'NODRIVER', 'FATAL' );
my $q = $tbl->select( $where_cond );
while ( my $href = $q->fetchrow_hashref() ) {
$self->post_add_record( $href );
}
return 1;
}
sub reindex_record {
# -------------------------------------------------------
# reindexes a record. basically deletes all associated records from current db abnd does an index.
# it's safe to use this
my $self = shift;
my $rec = shift;
$self->delete_record($rec);
$self->index_record($rec);
}
sub dump_index {
# -------------------------------------------------------
my $self = shift;
$self->{init} or $self->init_queries;
$self->{dump_word}->execute() or $self->error('CANTEXECUTE', 'WARN', $DBI::errstr);
$self->{dump_scor}->execute() or $self->error('CANTEXECUTE', 'WARN', $DBI::errstr);
}
sub debug_dumper {
# ------------------------------------------------------------------------------
# calls debug but also dumps all the messages
my $self = shift;
my $message = shift;
my $level = ref $_[0] ? 1 : shift;
if ( $self->{_debug} >= $level ) {
require GT::Dumper;
$self->debug( $message . join( "", map { GT::Dumper::Dumper($_) } @_ ));
}
}
sub DESTROY {
# ------------------------------------------------------------------------------
# Calls finish on init queries.
#
my $self = shift;
return unless ($self->{init});
$self->{upd_word}->finish;
# $self->{ins_word}->finish; will get finished automatically
$self->{sel_word}->finish;
$self->{sel_freq}->finish;
$self->{del_word}->finish;
$self->{mod_word}->finish;
$self->{ins_scor}->finish;
$self->{item_cnt}->finish;
$self->{scr_del}->finish;
$self->{dump_word}->finish;
$self->{dump_scor}->finish;
$self->{init} = 0;
}
1;