tsearch2-driver-procs.tcl

Procedures for tsearch full text engine driver

Location:

packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl

Created:

2004-06-05

Author:

Dave Bauer <dave@thedesignexperience.org>

CVS Identification:

$Id: tsearch2-driver-procs.tcl,v 1.41.2.12 2022/09/12 16:26:11 antoniop Exp $

Procedures in this file

• tsearch2::build_query_tcl (public)
• tsearch2::index (public)
• tsearch2::summary (public)
• tsearch2::unindex (public)
• tsearch2::update_index (public, deprecated)

Detailed information

 tsearch2::build_query_tcl [ -query query ]

 tsearch2::index object_id txt title keywords

 tsearch2::summary query txt

 tsearch2::unindex object_id

 tsearch2::update_index [ args... ]

Content File Source

ad_library {
    Procedures for tsearch full text engine driver

    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-06-05
    @cvs-id $Id: tsearch2-driver-procs.tcl,v 1.41.2.12 2022/09/12 16:26:11 antoniop Exp $
}

namespace eval tsearch2 {}

ad_proc -private tsearch2::trunc_to_max {txt} {

    tsearch has (at least up to PostgreSQL 10) the limitation that
    the length of tsvector is 1MB. so make sure, we do not raise
    errors, when this happens.

    https://www.postgresql.org/docs/current/static/textsearch-limitations.html
} {
    set max_size_to_index [parameter::get \
                               -package_id [apm_package_id_from_key tsearch2-driver] \
                               -parameter max_size_to_index \
                               -default 1048575]
    if {$max_size_to_index == 0} {
        set max_size_to_index 1048575
    }
    if {$max_size_to_index > 0 && [string length $txt] > $max_size_to_index} {
        ns_log notice "tsearch2: truncate overlong string to $max_size_to_index bytes"
        set txt [string range $txt 0 $max_size_to_index-1]
    }
    return $txt
}

d_proc -public tsearch2::index {
    object_id
    txt
    title
    keywords
} {
    Add or update an object in the full text index.

    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-06-05

    @param object_id
    @param txt
    @param title
    @param keywords

    @return nothing
} {
    set txt [tsearch2::trunc_to_max $txt]
    db_dml index {}
}

d_proc -public tsearch2::unindex {
    object_id
} {
    Remove item from FTS index

    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-06-05

    @param object_id

    @return nothing
} {
    db_dml unindex "delete from txt where object_id=:object_id"
}

ad_proc -deprecated tsearch2::update_index args {
    update full text index

    DEPRECATED: modern SQL supports upsert idioms

    @see tsearch2::index

    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-06-05

    @param object_id
    @param txt
    @param title
    @param keywords

    @return nothing
} {
    tsearch2::index {*}$args
}

d_proc -callback search::search -impl tsearch2-driver {
    -query
    {-user_id 0}
    {-offset 0}
    {-limit 10}
    {-df ""}
    {-dt ""}
    {-package_ids ""}
    {-object_type ""}
    {-extra_args {}}
} {
    ftsenginedriver search operation implementation for tsearch2

    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-06-05

    @param query
    @param user_id
    @param offset
    @param limit
    @param df
    @param dt
    @param package_ids
    @param object_type
    @param extra_args
    @return
    @error
} {
    set packages $package_ids
    set orig_query $query

    #
    # Clean up query for tsearch2
    #
    set query [tsearch2::build_query -query $query]
    # ns_log notice "-----build_query returned: $query"

    set where_clauses ""
    set from_clauses ""

    set limit_clause ""
    set offset_clause ""
    if {[string is integer -strict $limit]} {
        set limit_clause " limit $limit "
    }
    if {[string is integer -strict $offset]} {
        set offset_clause " offset $offset "
    }

    set need_acs_objects 0
    set base_query [db_map base_query]
    if {$df ne ""} {
        set need_acs_objects 1
        lappend where_clauses "o.creation_date > :df"
    }
    if {$dt ne ""} {
        set need_acs_objects 1
        lappend where_clauses "o.creation_date < :dt"
    }

    foreach {arg value} $extra_args {
        array set arg_clauses [lindex [callback -impl $arg search::extra_arg -value $value -object_table_alias "o"] 0]
        if {[info exists arg_clauses(from_clause)] && $arg_clauses(from_clause) ne ""} {
            lappend from_clauses $arg_clauses(from_clause)
        }
        if {[info exists arg_clauses(where_clause)] && $arg_clauses(where_clause) ne ""} {
            lappend where_clauses $arg_clauses(where_clause)
        }
    }
    if {[llength $extra_args]} {
        # extra_args can assume a join on acs_objects
        set need_acs_objects 1
    }
    # generate the package id restriction.
    set ids {}
    foreach id $packages {
        if {[string is integer -strict $id]} {
            lappend ids $id
        }
    }
    if {$ids ne ""} {
        set need_acs_objects 1
        lappend where_clauses "o.package_id in ([ns_dbquotelist $ids])"
    }
    if {$need_acs_objects} {
        lappend from_clauses "txt" "acs_objects o"
        lappend where_clauses "o.object_id = txt.object_id"
    } else {
        lappend from_clauses "txt"
    }

    set results_ids [db_list search {}]
    set count [db_string count {}]
    set stop_words {}

    #
    # Lovely the search package requires count to be returned but the
    # service contract definition doesn't specify it!
    #
    return [list ids $results_ids stopwords $stop_words count $count]
}

d_proc -public tsearch2::summary {
    query
    txt
} {
    Highlights matching terms.

    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-06-05

    @param query
    @param txt

    @return summary containing search query terms
    @error
} {
    set query [tsearch2::build_query -query $query]
    return [db_string summary {}]
}

d_proc -callback search::driver_info -impl tsearch2-driver {
} {
    Search driver info callback
} {
    return [tsearch2::driver_info]
}

ad_proc -private tsearch2::driver_info {} {
    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-06-05
} {
    return [list package_key tsearch2-driver version 2 automatic_and_queries_p 0  stopwords_p 1]
}

ad_proc tsearch2::build_query_tcl { -query } {
    Convert conjunctions to query characters for tsearch2
    and => &
    not => !
    or => |
    space => | (or)

    @param query string to convert
    @return returns formatted query string for tsearch2 tsquery
} {
    # get rid of everything that isn't valid in a query
    # letters, numbers, @ . - ( ) are all valid
    regsub -all {[^-/@.\d\w\s\(\)]+} $query { } query

    # match parens, if they don't match just throw them away
    set p 0
    for {set i 0} {$i < [string length $query]} {incr i} {
        switch [string index $query $i] {
            "(" {incr p}
            ")" {incr p -1}
        }
    }
    if {$p != 0} {
        regsub -all {\(|\)} $query {} query
    }

    # remove empty ()
    regsub -all {\(\s*\)} $query {} query

    # remove "or" at beginning of query
    regsub -nocase "^or " $query {} query

    # remove "not" at end of query
    regsub -nocase " not$" $query {} query

    # remove "not" alone
    regsub -nocase "^not$" $query {} query

    # replace boolean words with boolean operators
    regsub -nocase "^not " $query {!} query
    set query [string map {" and " " & " " or " " | " " not " " ! "} $query]

    # remove leading and trailing spaces so they aren't turned into &
    set query [string trim $query]

    # remove any spaces between words and operators
    # all remaining spaces between words turn into &
    while {[regexp {([-/@.\d\w\(\)])\s+?([-/@.\d\w\(\)])} $query]} {
        regsub {([-/@.\d\w\(\)])\s+?([-/@.\d\w\(\)])} $query {\1 \& \2} query
    }
    # if a ! is by itself then prepend &
    regsub -all {(\w+?)\s*(!)} $query {\1 \& !} query
    # if there is )( then insert an & between them
    # or if there is )\w or \w( insert an & between them
    regsub {(\))([\(\w])} $query {\1 \& \2} query
    regsub {([\)\w])(\()} $query {\1 \& \2} query
    if {[regsub {!|\||\&} $query {}] eq ""} {
        set query ""
    }
    return $query
}

ad_proc -private tsearch2::build_query_postgres { -query } {
    Convert conjunctions to query characters for tsearch2
    use websearch_to_tsquery which is integrated in postgres &gt;= 11

    websearch_to_tsquery creates a tsquery value from querytext using
    an alternative syntax in which simple unformatted text is a valid
    query. Unlike plainto_tsquery and phraseto_tsquery, it also
    recognizes certain operators. Moreover, this function should never
    raise syntax errors, which makes it possible to use raw user-supplied
    input for search. The following syntax is supported:

    <ul>
        <li>unquoted text: text not inside quote marks will be converted
        to terms separated by &amp; operators, as if processed by plainto_tsquery.</li>
        <li>"quoted text": text inside quote marks will be converted to terms
        separated by &lt;-&gt; operators, as if processed by phraseto_tsquery.</li>
        <li>OR: logical or will be converted to the | operator.</li>
        <li>-: the logical not operator, converted to the ! operator.</li>
    </ul>
    For further documentation see also:
    https://www.postgresql.org/docs/11/textsearch-controls.html#TEXTSEARCH-PARSING-QUERIES

    @param query string to convert
    @return returns formatted query string for tsearch2 tsquery
} {
    ad_try {
        db_1row build_querystring {select websearch_to_tsquery(:query) as query from dual}
    } on error {errorMsg} {
        ns_log warning "tsearch2 websearch_to_tsquery failed," \
            "fall back to tcl query builder query was: $query errorMsg: $errorMsg"
        set query [tsearch2::build_query_tcl -query $query]
    }
    return $query
}

d_proc -private tsearch2::build_query {
    -query
} {
    Build query string for tsearch2

    @param query string to convert
    @return returns formatted query string for tsearch2 tsquery
} {
    if {$::tsearch2_driver::use_web_search_p
        && [db_compatible_rdbms_p postgresql]
        && [lindex [split [db_version] .] 0] >= 11
    } {
        set query [tsearch2::build_query_postgres -query $query]
    } else {
        set query [tsearch2::build_query_tcl -query $query]
    }

    return $query
}

d_proc -private tsearch2::separate_query_and_operators {
    -query
} {
    Separates special operators from full text query

    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2004-07-10

    @param query

    @return list of query and operators

    @error
} {
    # remove evil characters
    regsub {\[|\]|\{|\}} $query {} query

    # match quotes
    set quote_count [regexp -all {\"} $query]
    # if quotes don't match, just remove all of them
    if {$quote_count % 2 == 1} {
        regsub -all {\"} $query {} query
    }

    set main_query ""
    set operators ""
    set last_operator ""
    set start_q 0
    set end_q 0
    set valid_operators [tsearch2_driver::valid_operators]
    foreach e [split $query] {
        if {[regexp {(^\w*):} $e discard operator]
            && $operator in $valid_operators
        } {
            # query element contains an operator, split operator from
            # query fragment
            set e [split $e ":"]
            set e [list $operator [lindex $e 1]]
        }
        # count quotes to see if this element
        # is part of a phrase
        if {$start_q ne 1} {
            set start_q [regexp {^\"} $e]
        }
        set end_q [regexp {\"$} $e]

        if {$start_q} {
            set sq {"}
        } else {
            set sq {}
        }
        if {$end_q} {
            set start_q 0
            set eq {"}
        } else {
            set eq {}
        }

        # now that we know if its parts of a phrase, get rid of the
        # quotes
        regsub -all {\"} $e {} e

        if {[llength $e] > 1} {
            # query element contains a valid operator
            lassign $e last_operator e
        } else {
            set last_operator ""
        }
        # regular search term
        ns_log debug "operator(e)='${e}' start_q=$start_q end_q=$end_q"
        if {$last_operator ne ""} {
            # FIXME need introspection for operator phrase support
            if {
                ($last_operator eq "title:" || $last_operator eq "description:")
                && ($start_q || $end_q)
            } {
                lappend ${last_operator}_phrase [regsub -all {\"} $e {}]
            } else {
                lappend $last_operator [regsub -all {\"} ${e} {}]
            }
        } else {
            if {$start_q || $end_q} {
                lappend phrase $e
            } else {
                lappend main_query $e
            }
        }
    }

    foreach op $valid_operators {
        if {[info exists $op] && [set $op] ne ""} {
            lappend operators $op $title
        }
    }
    lappend result $main_query
    if {$operators ne ""} {
        lappend result $operators
    }
    return $result
}

d_proc -private tsearch2_driver::valid_operators {
} {
    @author Dave Bauer (dave@thedesignexperience.org)
    @creation-date 2005-03-06

    @return list of advanced operator names

    @error
} {
    return {title description package_id parent_id}
}

#
# Local variables:
#    mode: tcl
#    tcl-indent-level: 4
#    indent-tabs-mode: nil
# End: