# 2009 November 04
#
# The author disclaims copyright to this source code. In place of
# a legal notice, here is a blessing:
#
# May you do good and not evil.
# May you find forgiveness for yourself and forgive others.
# May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file contains common code used the fts3 tests. At one point
# equivalent functionality was implemented in C code. But it is easier
# to use Tcl.
#
#-------------------------------------------------------------------------
# USAGE: fts3_integrity_check TBL
#
# This proc is used to verify that the full-text index is consistent with
# the contents of the fts3 table. In other words, it checks that the
# data in the %_contents table matches that in the %_segdir and %_segments
# tables.
#
# This is not an efficient procedure. It uses a lot of memory and a lot
# of CPU. But it is better than not checking at all.
#
# The procedure is:
#
# 1) Read the entire full-text index from the %_segdir and %_segments
# tables into memory. For each entry in the index, the following is
# done:
#
# set C($iDocid,$iCol,$iPosition) $zTerm
#
# 2) Iterate through each column of each row of the %_content table.
# Tokenize all documents, and check that for each token there is
# a corresponding entry in the $C array. After checking a token,
# [unset] the $C array entry.
#
# 3) Check that array $C is now empty.
#
#
proc fts3_integrity_check {tbl} {
fts3_read2 $tbl 1 A
foreach zTerm [array names A] {
foreach doclist $A($zTerm) {
set docid 0
while {[string length $doclist]>0} {
set iCol 0
set iPos 0
set lPos [list]
set lCol [list]
# First varint of a doclist-entry is the docid. Delta-compressed
# with respect to the docid of the previous entry.
#
incr docid [gobble_varint doclist]
if {[info exists D($zTerm,$docid)]} {
while {[set iDelta [gobble_varint doclist]] != 0} {}
continue
}
set D($zTerm,$docid) 1
# Gobble varints until the 0x00 that terminates the doclist-entry
# is found.
while {[set iDelta [gobble_varint doclist]] > 0} {
if {$iDelta == 1} {
set iCol [gobble_varint doclist]
set iPos 0
} else {
incr iPos $iDelta
incr iPos -2
set C($docid,$iCol,$iPos) $zTerm
}
}
}
}
}
foreach key [array names C] {
#puts "$key -> $C($key)"
}
db eval "SELECT * FROM ${tbl}_content" E {
set iCol 0
set iDoc $E(docid)
foreach col [lrange $E(*) 1 end] {
set c $E($col)
set sql {SELECT fts3_tokenizer_test('simple', $c)}
foreach {pos term dummy} [db one $sql] {
if {![info exists C($iDoc,$iCol,$pos)]} {
set es "Error at docid=$iDoc col=$iCol pos=$pos. Index is missing"
lappend errors $es
} else {
if {$C($iDoc,$iCol,$pos) != "$term"} {
set es "Error at docid=$iDoc col=$iCol pos=$pos. Index "
append es "has \"$C($iDoc,$iCol,$pos)\", document has \"$term\""
lappend errors $es
}
unset C($iDoc,$iCol,$pos)
}
}
incr iCol
}
}
foreach c [array names C] {
lappend errors "Bad index entry: $c -> $C($c)"
}
if {[info exists errors]} { return [join $errors "\n"] }
return "ok"
}
# USAGE: fts3_terms TBL WHERE
#
# Argument TBL must be the name of an FTS3 table. Argument WHERE is an
# SQL expression that will be used as the WHERE clause when scanning
# the %_segdir table. As in the following query:
#
# "SELECT * FROM ${TBL}_segdir WHERE ${WHERE}"
#
# This function returns a list of all terms present in the segments
# selected by the statement above.
#
proc fts3_terms {tbl where} {
fts3_read $tbl $where a
return [lsort [array names a]]
}
# USAGE: fts3_doclist TBL TERM WHERE
#
# Argument TBL must be the name of an FTS3 table. TERM is a term that may
# or may not be present in the table. Argument WHERE is used to select a
# subset of the b-tree segments in the associated full-text index as
# described above for [fts3_terms].
#
# This function returns the results of merging the doclists associated
# with TERM in the selected segments. Each doclist is an element of the
# returned list. Each doclist is formatted as follows:
#
# [$docid ?$col[$off1 $off2...]?...]
#
# The formatting is odd for a Tcl command in order to be compatible with
# the original C-language implementation. If argument WHERE is "1", then
# any empty doclists are omitted from the returned list.
#
proc fts3_doclist {tbl term where} {
fts3_read $tbl $where a
foreach doclist $a($term) {
set docid 0
while {[string length $doclist]>0} {
set iCol 0
set iPos 0
set lPos [list]
set lCol [list]
incr docid [gobble_varint doclist]
while {[set iDelta [gobble_varint doclist]] > 0} {
if {$iDelta == 1} {
lappend lCol [list $iCol $lPos]
set iPos 0
set lPos [list]
set iCol [gobble_varint doclist]
} else {
incr iPos $iDelta
incr iPos -2
lappend lPos $iPos
}
}
if {[llength $lPos]>0} {
lappend lCol [list $iCol $lPos]
}
if {$where != "1" || [llength $lCol]>0} {
set ret($docid) $lCol
} else {
unset -nocomplain ret($docid)
}
}
}
set lDoc [list]
foreach docid [lsort -integer [array names ret]] {
set lCol [list]
set cols ""
foreach col $ret($docid) {
foreach {iCol lPos} $col {}
append cols " $iCol\[[join $lPos { }]\]"
}
lappend lDoc "\[${docid}${cols}\]"
}
join $lDoc " "
}
###########################################################################
proc gobble_varint {varname} {
upvar $varname blob
set n [read_varint $blob ret]
set blob [string range $blob $n end]
return $ret
}
proc gobble_string {varname nLength} {
upvar $varname blob
set ret [string range $blob 0 [expr $nLength-1]]
set blob [string range $blob $nLength end]
return $ret
}
# The argument is a blob of data representing an FTS3 segment leaf.
# Return a list consisting of alternating terms (strings) and doclists
# (blobs of data).
#
proc fts3_readleaf {blob} {
set zPrev ""
set terms [list]
while {[string length $blob] > 0} {
set nPrefix [gobble_varint blob]
set nSuffix [gobble_varint blob]
set zTerm [string range $zPrev 0 [expr $nPrefix-1]]
append zTerm [gobble_string blob $nSuffix]
set doclist [gobble_string blob [gobble_varint blob]]
lappend terms $zTerm $doclist
set zPrev $zTerm
}
return $terms
}
proc fts3_read2 {tbl where varname} {
upvar $varname a
array unset a
db eval " SELECT start_block, leaves_end_block, root
FROM ${tbl}_segdir WHERE $where
ORDER BY level ASC, idx DESC
" {
if {$start_block == 0} {
foreach {t d} [fts3_readleaf $root] { lappend a($t) $d }
} else {
db eval " SELECT block
FROM ${tbl}_segments
WHERE blockid>=$start_block AND blockid<=$leaves_end_block
ORDER BY blockid
" {
foreach {t d} [fts3_readleaf $block] { lappend a($t) $d }
}
}
}
}
proc fts3_read {tbl where varname} {
upvar $varname a
array unset a
db eval " SELECT start_block, leaves_end_block, root
FROM ${tbl}_segdir WHERE $where
ORDER BY level DESC, idx ASC
" {
if {$start_block == 0} {
foreach {t d} [fts3_readleaf $root] { lappend a($t) $d }
} else {
db eval " SELECT block
FROM ${tbl}_segments
WHERE blockid>=$start_block AND blockid<$leaves_end_block
ORDER BY blockid
" {
foreach {t d} [fts3_readleaf $block] { lappend a($t) $d }
}
}
}
}