/* Copyright (C) 2006 J.F.Dockes
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
// Handle translation from rcl's SearchData structures to Xapian Queries
#include "autoconfig.h"
#include <stdio.h>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
using namespace std;
#include "xapian.h"
#include "cstr.h"
#include "rcldb.h"
#include "rcldb_p.h"
#include "searchdata.h"
#include "debuglog.h"
#include "smallut.h"
#include "textsplit.h"
#include "unacpp.h"
#include "utf8iter.h"
#include "stoplist.h"
#include "rclconfig.h"
#include "termproc.h"
#include "synfamily.h"
#include "stemdb.h"
#include "expansiondbs.h"
#include "base64.h"
#include "daterange.h"
namespace Rcl {
typedef vector<SearchDataClause *>::iterator qlist_it_t;
static const int original_term_wqf_booster = 10;
// Expand categories and mime type wild card exps Categories are
// expanded against the configuration, mimetypes against the index
// (for wildcards).
bool SearchData::expandFileTypes(Db &db, vector<string>& tps)
{
const RclConfig *cfg = db.getConf();
if (!cfg) {
LOGFATAL(("Db::expandFileTypes: null configuration!!\n"));
return false;
}
vector<string> exptps;
for (vector<string>::iterator it = tps.begin(); it != tps.end(); it++) {
if (cfg->isMimeCategory(*it)) {
vector<string>tps;
cfg->getMimeCatTypes(*it, tps);
exptps.insert(exptps.end(), tps.begin(), tps.end());
} else {
TermMatchResult res;
string mt = stringtolower((const string&)*it);
// We set casesens|diacsens to get an equivalent of ixTermMatch()
db.termMatch(Db::ET_WILD|Db::ET_CASESENS|Db::ET_DIACSENS, string(),
mt, res, -1, "mtype");
if (res.entries.empty()) {
exptps.push_back(it->c_str());
} else {
for (vector<TermMatchEntry>::const_iterator rit =
res.entries.begin(); rit != res.entries.end(); rit++) {
exptps.push_back(strip_prefix(rit->term));
}
}
}
}
sort(exptps.begin(), exptps.end());
exptps.erase(unique(exptps.begin(), exptps.end()), exptps.end());
tps = exptps;
return true;
}
static const char *maxXapClauseMsg =
"Maximum Xapian query size exceeded. Increase maxXapianClauses "
"in the configuration. ";
static const char *maxXapClauseCaseDiacMsg =
"Or try to use case (C) or diacritics (D) sensitivity qualifiers, or less "
"wildcards ?"
;
bool SearchData::clausesToQuery(Rcl::Db &db, SClType tp,
vector<SearchDataClause*>& query,
string& reason, void *d)
{
Xapian::Query xq;
for (qlist_it_t it = query.begin(); it != query.end(); it++) {
Xapian::Query nq;
if (!(*it)->toNativeQuery(db, &nq)) {
LOGERR(("SearchData::clausesToQuery: toNativeQuery failed: %s\n",
(*it)->getReason().c_str()));
reason += (*it)->getReason() + " ";
return false;
}
if (nq.empty()) {
LOGDEB(("SearchData::clausesToQuery: skipping empty clause\n"));
continue;
}
// If this structure is an AND list, must use AND_NOT for excl clauses.
// Else this is an OR list, and there can't be excl clauses (checked by
// addClause())
Xapian::Query::op op;
if (tp == SCLT_AND) {
if ((*it)->getexclude()) {
op = Xapian::Query::OP_AND_NOT;
} else {
op = Xapian::Query::OP_AND;
}
} else {
op = Xapian::Query::OP_OR;
}
if (xq.empty()) {
if (op == Xapian::Query::OP_AND_NOT)
xq = Xapian::Query(op, Xapian::Query::MatchAll, nq);
else
xq = nq;
} else {
xq = Xapian::Query(op, xq, nq);
}
if (int(xq.get_length()) >= getMaxCl()) {
LOGERR(("%s\n", maxXapClauseMsg));
m_reason += maxXapClauseMsg;
if (!o_index_stripchars)
m_reason += maxXapClauseCaseDiacMsg;
return false;
}
}
LOGDEB0(("SearchData::clausesToQuery: got %d clauses\n", xq.get_length()));
if (xq.empty())
xq = Xapian::Query::MatchAll;
*((Xapian::Query *)d) = xq;
return true;
}
bool SearchData::toNativeQuery(Rcl::Db &db, void *d)
{
LOGDEB(("SearchData::toNativeQuery: stemlang [%s]\n", m_stemlang.c_str()));
m_reason.erase();
db.getConf()->getConfParam("maxTermExpand", &m_maxexp);
db.getConf()->getConfParam("maxXapianClauses", &m_maxcl);
// Walk the clause list translating each in turn and building the
// Xapian query tree
Xapian::Query xq;
if (!clausesToQuery(db, m_tp, m_query, m_reason, &xq)) {
LOGERR(("SearchData::toNativeQuery: clausesToQuery failed. reason: %s\n",
m_reason.c_str()));
return false;
}
if (m_haveDates) {
// If one of the extremities is unset, compute db extremas
if (m_dates.y1 == 0 || m_dates.y2 == 0) {
int minyear = 1970, maxyear = 2100;
if (!db.maxYearSpan(&minyear, &maxyear)) {
LOGERR(("Can't retrieve index min/max dates\n"));
//whatever, go on.
}
if (m_dates.y1 == 0) {
m_dates.y1 = minyear;
m_dates.m1 = 1;
m_dates.d1 = 1;
}
if (m_dates.y2 == 0) {
m_dates.y2 = maxyear;
m_dates.m2 = 12;
m_dates.d2 = 31;
}
}
LOGDEB(("Db::toNativeQuery: date interval: %d-%d-%d/%d-%d-%d\n",
m_dates.y1, m_dates.m1, m_dates.d1,
m_dates.y2, m_dates.m2, m_dates.d2));
Xapian::Query dq = date_range_filter(m_dates.y1, m_dates.m1, m_dates.d1,
m_dates.y2, m_dates.m2, m_dates.d2);
if (dq.empty()) {
LOGINFO(("Db::toNativeQuery: date filter is empty\n"));
}
// If no probabilistic query is provided then promote the daterange
// filter to be THE query instead of filtering an empty query.
if (xq.empty()) {
LOGINFO(("Db::toNativeQuery: proba query is empty\n"));
xq = dq;
} else {
xq = Xapian::Query(Xapian::Query::OP_FILTER, xq, dq);
}
}
if (m_minSize != size_t(-1) || m_maxSize != size_t(-1)) {
Xapian::Query sq;
char min[50], max[50];
sprintf(min, "%lld", (long long)m_minSize);
sprintf(max, "%lld", (long long)m_maxSize);
if (m_minSize == size_t(-1)) {
string value(max);
leftzeropad(value, 12);
sq = Xapian::Query(Xapian::Query::OP_VALUE_LE, VALUE_SIZE, value);
} else if (m_maxSize == size_t(-1)) {
string value(min);
leftzeropad(value, 12);
sq = Xapian::Query(Xapian::Query::OP_VALUE_GE, VALUE_SIZE, value);
} else {
string minvalue(min);
leftzeropad(minvalue, 12);
string maxvalue(max);
leftzeropad(maxvalue, 12);
sq = Xapian::Query(Xapian::Query::OP_VALUE_RANGE, VALUE_SIZE,
minvalue, maxvalue);
}
// If no probabilistic query is provided then promote the
// filter to be THE query instead of filtering an empty query.
if (xq.empty()) {
LOGINFO(("Db::toNativeQuery: proba query is empty\n"));
xq = sq;
} else {
xq = Xapian::Query(Xapian::Query::OP_FILTER, xq, sq);
}
}
// Add the autophrase if any
if (m_autophrase.isNotNull()) {
Xapian::Query apq;
if (m_autophrase->toNativeQuery(db, &apq)) {
xq = xq.empty() ? apq :
Xapian::Query(Xapian::Query::OP_AND_MAYBE, xq, apq);
}
}
// Add the file type filtering clause if any
if (!m_filetypes.empty()) {
expandFileTypes(db, m_filetypes);
Xapian::Query tq;
for (vector<string>::iterator it = m_filetypes.begin();
it != m_filetypes.end(); it++) {
string term = wrap_prefix(mimetype_prefix) + *it;
LOGDEB0(("Adding file type term: [%s]\n", term.c_str()));
tq = tq.empty() ? Xapian::Query(term) :
Xapian::Query(Xapian::Query::OP_OR, tq, Xapian::Query(term));
}
xq = xq.empty() ? tq : Xapian::Query(Xapian::Query::OP_FILTER, xq, tq);
}
// Add the neg file type filtering clause if any
if (!m_nfiletypes.empty()) {
expandFileTypes(db, m_nfiletypes);
Xapian::Query tq;
for (vector<string>::iterator it = m_nfiletypes.begin();
it != m_nfiletypes.end(); it++) {
string term = wrap_prefix(mimetype_prefix) + *it;
LOGDEB0(("Adding negative file type term: [%s]\n", term.c_str()));
tq = tq.empty() ? Xapian::Query(term) :
Xapian::Query(Xapian::Query::OP_OR, tq, Xapian::Query(term));
}
xq = xq.empty() ? tq : Xapian::Query(Xapian::Query::OP_AND_NOT, xq, tq);
}
*((Xapian::Query *)d) = xq;
return true;
}
// Splitter for breaking a user string into simple terms and
// phrases. This is for parts of the user entry which would appear as
// a single word because there is no white space inside, but are
// actually multiple terms to rcldb (ie term1,term2). Still, most of
// the time, the result of our splitting will be a single term.
class TextSplitQ : public TextSplitP {
public:
TextSplitQ(Flags flags, TermProc *prc)
: TextSplitP(prc, flags), m_nostemexp(false) {
}
bool takeword(const std::string &term, int pos, int bs, int be) {
// Check if the first letter is a majuscule in which
// case we do not want to do stem expansion. Need to do this
// before unac of course...
m_nostemexp = unaciscapital(term);
return TextSplitP::takeword(term, pos, bs, be);
}
bool nostemexp() const {
return m_nostemexp;
}
private:
bool m_nostemexp;
};
class TermProcQ : public TermProc {
public:
TermProcQ() : TermProc(0), m_alltermcount(0), m_lastpos(0), m_ts(0) {}
// We need a ref to the splitter (only it knows about orig term
// capitalization for controlling stemming. The ref can't be set
// in the constructor because the splitter is not built yet when
// we are born (chicken and egg).
void setTSQ(const TextSplitQ *ts) {
m_ts = ts;
}
bool takeword(const std::string &term, int pos, int bs, int be) {
m_alltermcount++;
if (m_lastpos < pos)
m_lastpos = pos;
bool noexpand = be ? m_ts->nostemexp() : true;
LOGDEB1(("TermProcQ::takeword: pushing [%s] pos %d noexp %d\n",
term.c_str(), pos, noexpand));
if (m_terms[pos].size() < term.size()) {
m_terms[pos] = term;
m_nste[pos] = noexpand;
}
return true;
}
bool flush() {
for (map<int, string>::const_iterator it = m_terms.begin();
it != m_terms.end(); it++) {
m_vterms.push_back(it->second);
m_vnostemexps.push_back(m_nste[it->first]);
}
return true;
}
int alltermcount() const {
return m_alltermcount;
}
int lastpos() const {
return m_lastpos;
}
const vector<string>& terms() {
return m_vterms;
}
const vector<bool>& nostemexps() {
return m_vnostemexps;
}
private:
// Count of terms including stopwords: this is for adjusting
// phrase/near slack
int m_alltermcount;
int m_lastpos;
const TextSplitQ *m_ts;
vector<string> m_vterms;
vector<bool> m_vnostemexps;
map<int, string> m_terms;
map<int, bool> m_nste;
};
#if 1
static void listVector(const string& what, const vector<string>&l)
{
string a;
for (vector<string>::const_iterator it = l.begin(); it != l.end(); it++) {
a = a + *it + " ";
}
LOGDEB0(("%s: %s\n", what.c_str(), a.c_str()));
}
#endif
/** Expand term into term list, using appropriate mode: stem, wildcards,
* diacritics...
*
* @param mods stem expansion, case and diacritics sensitivity control.
* @param term input single word
* @param oexp output expansion list
* @param sterm output original input term if there were no wildcards
* @param prefix field prefix in index. We could recompute it, but the caller
* has it already. Used in the simple case where there is nothing to expand,
* and we just return the prefixed term (else Db::termMatch deals with it).
*/
bool SearchDataClauseSimple::expandTerm(Rcl::Db &db,
string& ermsg, int mods,
const string& term,
vector<string>& oexp, string &sterm,
const string& prefix)
{
LOGDEB0(("expandTerm: mods 0x%x fld [%s] trm [%s] lang [%s]\n",
mods, m_field.c_str(), term.c_str(), getStemLang().c_str()));
sterm.clear();
oexp.clear();
if (term.empty())
return true;
bool maxexpissoft = false;
int maxexpand = getSoftMaxExp();
if (maxexpand != -1) {
maxexpissoft = true;
} else {
maxexpand = getMaxExp();
}
bool haswild = term.find_first_of(cstr_minwilds) != string::npos;
// If there are no wildcards, add term to the list of user-entered terms
if (!haswild) {
m_hldata.uterms.insert(term);
sterm = term;
}
// No stem expansion if there are wildcards or if prevented by caller
bool nostemexp = (mods & SDCM_NOSTEMMING) != 0;
if (haswild || getStemLang().empty()) {
LOGDEB2(("expandTerm: found wildcards or stemlang empty: no exp\n"));
nostemexp = true;
}
// noexpansion can be modified further down by possible case/diac expansion
bool noexpansion = nostemexp && !haswild;
int termmatchsens = 0;
bool diac_sensitive = (mods & SDCM_DIACSENS) != 0;
bool case_sensitive = (mods & SDCM_CASESENS) != 0;
if (o_index_stripchars) {
diac_sensitive = case_sensitive = false;
} else {
// If we are working with a raw index, apply the rules for case and
// diacritics sensitivity.
// If any character has a diacritic, we become
// diacritic-sensitive. Note that the way that the test is
// performed (conversion+comparison) will automatically ignore
// accented characters which are actually a separate letter
if (getAutoDiac() && unachasaccents(term)) {
LOGDEB0(("expandTerm: term has accents -> diac-sensitive\n"));
diac_sensitive = true;
}
// If any character apart the first is uppercase, we become
// case-sensitive. The first character is reserved for
// turning off stemming. You need to use a query language
// modifier to search for Floor in a case-sensitive way.
Utf8Iter it(term);
it++;
if (getAutoCase() && unachasuppercase(term.substr(it.getBpos()))) {
LOGDEB0(("expandTerm: term has uppercase -> case-sensitive\n"));
case_sensitive = true;
}
// If we are sensitive to case or diacritics turn stemming off
if (diac_sensitive || case_sensitive) {
LOGDEB0(("expandTerm: diac or case sens set -> stemexpand off\n"));
nostemexp = true;
}
if (!case_sensitive || !diac_sensitive)
noexpansion = false;
}
if (case_sensitive)
termmatchsens |= Db::ET_CASESENS;
if (diac_sensitive)
termmatchsens |= Db::ET_DIACSENS;
if (noexpansion) {
oexp.push_back(prefix + term);
m_hldata.terms[term] = term;
LOGDEB(("ExpandTerm: noexpansion: final: %s\n", stringsToString(oexp).c_str()));
return true;
}
Db::MatchType mtyp = haswild ? Db::ET_WILD :
nostemexp ? Db::ET_NONE : Db::ET_STEM;
TermMatchResult res;
if (!db.termMatch(mtyp | termmatchsens, getStemLang(), term, res, maxexpand,
m_field)) {
// Let it go through
}
// Term match entries to vector of terms
if (int(res.entries.size()) >= maxexpand && !maxexpissoft) {
ermsg = "Maximum term expansion size exceeded."
" Maybe use case/diacritics sensitivity or increase maxTermExpand.";
return false;
}
for (vector<TermMatchEntry>::const_iterator it = res.entries.begin();
it != res.entries.end(); it++) {
oexp.push_back(it->term);
}
// If the term does not exist at all in the db, the return from
// termMatch() is going to be empty, which is not what we want (we
// would then compute an empty Xapian query)
if (oexp.empty())
oexp.push_back(prefix + term);
// Remember the uterm-to-expansion links
for (vector<string>::const_iterator it = oexp.begin();
it != oexp.end(); it++) {
m_hldata.terms[strip_prefix(*it)] = term;
}
LOGDEB(("ExpandTerm: final: %s\n", stringsToString(oexp).c_str()));
return true;
}
// Do distribution of string vectors: a,b c,d -> a,c a,d b,c b,d
void multiply_groups(vector<vector<string> >::const_iterator vvit,
vector<vector<string> >::const_iterator vvend,
vector<string>& comb,
vector<vector<string> >&allcombs)
{
// Remember my string vector and compute next, for recursive calls.
vector<vector<string> >::const_iterator myvit = vvit++;
// Walk the string vector I'm called upon and, for each string,
// add it to current result, an call myself recursively on the
// next string vector. The last call (last element of the vector of
// vectors), adds the elementary result to the output
// Walk my string vector
for (vector<string>::const_iterator strit = (*myvit).begin();
strit != (*myvit).end(); strit++) {
// Add my current value to the string vector we're building
comb.push_back(*strit);
if (vvit == vvend) {
// Last call: store current result
allcombs.push_back(comb);
} else {
// Call recursively on next string vector
multiply_groups(vvit, vvend, comb, allcombs);
}
// Pop the value I just added (make room for the next element in my
// vector)
comb.pop_back();
}
}
void SearchDataClauseSimple::processSimpleSpan(Rcl::Db &db, string& ermsg,
const string& span,
int mods, void * pq)
{
vector<Xapian::Query>& pqueries(*(vector<Xapian::Query>*)pq);
LOGDEB0(("StringToXapianQ::processSimpleSpan: [%s] mods 0x%x\n",
span.c_str(), (unsigned int)mods));
vector<string> exp;
string sterm; // dumb version of user term
string prefix;
const FieldTraits *ftp;
if (!m_field.empty() && db.fieldToTraits(m_field, &ftp, true)) {
prefix = wrap_prefix(ftp->pfx);
}
if (!expandTerm(db, ermsg, mods, span, exp, sterm, prefix))
return;
// Set up the highlight data. No prefix should go in there
for (vector<string>::const_iterator it = exp.begin();
it != exp.end(); it++) {
m_hldata.groups.push_back(vector<string>(1, it->substr(prefix.size())));
m_hldata.slacks.push_back(0);
m_hldata.grpsugidx.push_back(m_hldata.ugroups.size() - 1);
}
// Push either term or OR of stem-expanded set
Xapian::Query xq(Xapian::Query::OP_OR, exp.begin(), exp.end());
m_curcl += exp.size();
// If sterm (simplified original user term) is not null, give it a
// relevance boost. We do this even if no expansion occurred (else
// the non-expanded terms in a term list would end-up with even
// less wqf). This does not happen if there are wildcards anywhere
// in the search.
// We normally boost the original term in the stem expansion list. Don't
// do it if there are wildcards anywhere, this would skew the results.
bool doBoostUserTerm =
(m_parentSearch && !m_parentSearch->haveWildCards()) ||
(m_parentSearch == 0 && !m_haveWildCards);
if (doBoostUserTerm && !sterm.empty()) {
xq = Xapian::Query(Xapian::Query::OP_OR, xq,
Xapian::Query(prefix+sterm,
original_term_wqf_booster));
}
pqueries.push_back(xq);
}
// User entry element had several terms: transform into a PHRASE or
// NEAR xapian query, the elements of which can themselves be OR
// queries if the terms get expanded by stemming or wildcards (we
// don't do stemming for PHRASE though)
void SearchDataClauseSimple::processPhraseOrNear(Rcl::Db &db, string& ermsg,
TermProcQ *splitData,
int mods, void *pq,
bool useNear, int slack)
{
vector<Xapian::Query> &pqueries(*(vector<Xapian::Query>*)pq);
Xapian::Query::op op = useNear ? Xapian::Query::OP_NEAR :
Xapian::Query::OP_PHRASE;
vector<Xapian::Query> orqueries;
#ifdef XAPIAN_NEAR_EXPAND_SINGLE_BUF
bool hadmultiple = false;
#endif
vector<vector<string> >groups;
string prefix;
const FieldTraits *ftp;
if (!m_field.empty() && db.fieldToTraits(m_field, &ftp, true)) {
prefix = wrap_prefix(ftp->pfx);
}
if (mods & Rcl::SearchDataClause::SDCM_ANCHORSTART) {
orqueries.push_back(Xapian::Query(prefix + start_of_field_term));
slack++;
}
// Go through the list and perform stem/wildcard expansion for each element
vector<bool>::const_iterator nxit = splitData->nostemexps().begin();
for (vector<string>::const_iterator it = splitData->terms().begin();
it != splitData->terms().end(); it++, nxit++) {
LOGDEB0(("ProcessPhrase: processing [%s]\n", it->c_str()));
// Adjust when we do stem expansion. Not if disabled by
// caller, not inside phrases, and some versions of xapian
// will accept only one OR clause inside NEAR.
bool nostemexp = *nxit || (op == Xapian::Query::OP_PHRASE)
#ifdef XAPIAN_NEAR_EXPAND_SINGLE_BUF
|| hadmultiple
#endif // single OR inside NEAR
;
int lmods = mods;
if (nostemexp)
lmods |= SearchDataClause::SDCM_NOSTEMMING;
string sterm;
vector<string> exp;
if (!expandTerm(db, ermsg, lmods, *it, exp, sterm, prefix))
return;
LOGDEB0(("ProcessPhraseOrNear: exp size %d\n", exp.size()));
listVector("", exp);
// groups is used for highlighting, we don't want prefixes in there.
vector<string> noprefs;
for (vector<string>::const_iterator it = exp.begin();
it != exp.end(); it++) {
noprefs.push_back(it->substr(prefix.size()));
}
groups.push_back(noprefs);
orqueries.push_back(Xapian::Query(Xapian::Query::OP_OR,
exp.begin(), exp.end()));
m_curcl += exp.size();
if (m_curcl >= getMaxCl())
return;
#ifdef XAPIAN_NEAR_EXPAND_SINGLE_BUF
if (exp.size() > 1)
hadmultiple = true;
#endif
}
if (mods & Rcl::SearchDataClause::SDCM_ANCHOREND) {
orqueries.push_back(Xapian::Query(prefix + end_of_field_term));
slack++;
}
// Generate an appropriate PHRASE/NEAR query with adjusted slack
// For phrases, give a relevance boost like we do for original terms
LOGDEB2(("PHRASE/NEAR: alltermcount %d lastpos %d\n",
splitData->alltermcount(), splitData->lastpos()));
Xapian::Query xq(op, orqueries.begin(), orqueries.end(),
splitData->lastpos() + 1 + slack);
if (op == Xapian::Query::OP_PHRASE)
xq = Xapian::Query(Xapian::Query::OP_SCALE_WEIGHT, xq,
original_term_wqf_booster);
pqueries.push_back(xq);
// Add all combinations of NEAR/PHRASE groups to the highlighting data.
vector<vector<string> > allcombs;
vector<string> comb;
multiply_groups(groups.begin(), groups.end(), comb, allcombs);
// Insert the search groups and slacks in the highlight data, with
// a reference to the user entry that generated them:
m_hldata.groups.insert(m_hldata.groups.end(),
allcombs.begin(), allcombs.end());
m_hldata.slacks.insert(m_hldata.slacks.end(), allcombs.size(), slack);
m_hldata.grpsugidx.insert(m_hldata.grpsugidx.end(), allcombs.size(),
m_hldata.ugroups.size() - 1);
}
// Trim string beginning with ^ or ending with $ and convert to flags
static int stringToMods(string& s)
{
int mods = 0;
// Check for an anchored search
trimstring(s);
if (s.length() > 0 && s[0] == '^') {
mods |= Rcl::SearchDataClause::SDCM_ANCHORSTART;
s.erase(0, 1);
}
if (s.length() > 0 && s[s.length()-1] == '$') {
mods |= Rcl::SearchDataClause::SDCM_ANCHOREND;
s.erase(s.length()-1);
}
return mods;
}
/**
* Turn user entry string (NOT query language) into a list of xapian queries.
* We just separate words and phrases, and do wildcard and stem expansion,
*
* This is used to process data entered into an OR/AND/NEAR/PHRASE field of
* the GUI (in the case of NEAR/PHRASE, clausedist adds dquotes to the user
* entry).
*
* This appears awful, and it would seem that the split into
* terms/phrases should be performed in the upper layer so that we
* only receive pure term or near/phrase pure elements here, but in
* fact there are things that would appear like terms to naive code,
* and which will actually may be turned into phrases (ie: tom:jerry),
* in a manner which intimately depends on the index implementation,
* so that it makes sense to process this here.
*
* The final list contains one query for each term or phrase
* - Elements corresponding to a stem-expanded part are an OP_OR
* composition of the stem-expanded terms (or a single term query).
* - Elements corresponding to phrase/near are an OP_PHRASE/NEAR
* composition of the phrase terms (no stem expansion in this case)
* @return the subquery count (either or'd stem-expanded terms or phrase word
* count)
*/
bool SearchDataClauseSimple::processUserString(Rcl::Db &db, const string &iq,
string &ermsg, void *pq,
int slack, bool useNear)
{
vector<Xapian::Query> &pqueries(*(vector<Xapian::Query>*)pq);
int mods = m_modifiers;
LOGDEB(("StringToXapianQ:pUS:: qstr [%s] fld [%s] mods 0x%x "
"slack %d near %d\n",
iq.c_str(), m_field.c_str(), mods, slack, useNear));
ermsg.erase();
m_curcl = 0;
const StopList stops = db.getStopList();
// Simple whitespace-split input into user-level words and
// double-quoted phrases: word1 word2 "this is a phrase".
//
// The text splitter may further still decide that the resulting
// "words" are really phrases, this depends on separators:
// [paul@dom.net] would still be a word (span), but [about:me]
// will probably be handled as a phrase.
vector<string> phrases;
TextSplit::stringToStrings(iq, phrases);
// Process each element: textsplit into terms, handle stem/wildcard
// expansion and transform into an appropriate Xapian::Query
try {
for (vector<string>::iterator it = phrases.begin();
it != phrases.end(); it++) {
LOGDEB0(("strToXapianQ: phrase/word: [%s]\n", it->c_str()));
// Anchoring modifiers
int amods = stringToMods(*it);
int terminc = amods != 0 ? 1 : 0;
mods |= amods;
// If there are multiple spans in this element, including
// at least one composite, we have to increase the slack
// else a phrase query including a span would fail.
// Ex: "term0@term1 term2" is onlyspans-split as:
// 0 term0@term1 0 12
// 2 term2 13 18
// The position of term2 is 2, not 1, so a phrase search
// would fail.
// We used to do word split, searching for
// "term0 term1 term2" instead, which may have worse
// performance, but will succeed.
// We now adjust the phrase/near slack by comparing the term count
// and the last position
// The term processing pipeline:
// split -> [unac/case ->] stops -> store terms
TermProcQ tpq;
TermProc *nxt = &tpq;
TermProcStop tpstop(nxt, stops); nxt = &tpstop;
//TermProcCommongrams tpcommon(nxt, stops); nxt = &tpcommon;
//tpcommon.onlygrams(true);
TermProcPrep tpprep(nxt);
if (o_index_stripchars)
nxt = &tpprep;
TextSplitQ splitter(TextSplit::Flags(TextSplit::TXTS_ONLYSPANS |
TextSplit::TXTS_KEEPWILD),
nxt);
tpq.setTSQ(&splitter);
splitter.text_to_words(*it);
slack += tpq.lastpos() - tpq.terms().size() + 1;
LOGDEB0(("strToXapianQ: termcount: %d\n", tpq.terms().size()));
switch (tpq.terms().size() + terminc) {
case 0:
continue;// ??
case 1: {
int lmods = mods;
if (tpq.nostemexps().front())
lmods |= SearchDataClause::SDCM_NOSTEMMING;
m_hldata.ugroups.push_back(tpq.terms());
processSimpleSpan(db, ermsg, tpq.terms().front(),
lmods, &pqueries);
}
break;
default:
m_hldata.ugroups.push_back(tpq.terms());
processPhraseOrNear(db, ermsg, &tpq, mods, &pqueries,
useNear, slack);
}
if (m_curcl >= getMaxCl()) {
ermsg = maxXapClauseMsg;
if (!o_index_stripchars)
ermsg += maxXapClauseCaseDiacMsg;
break;
}
}
} catch (const Xapian::Error &e) {
ermsg = e.get_msg();
} catch (const string &s) {
ermsg = s;
} catch (const char *s) {
ermsg = s;
} catch (...) {
ermsg = "Caught unknown exception";
}
if (!ermsg.empty()) {
LOGERR(("stringToXapianQueries: %s\n", ermsg.c_str()));
return false;
}
return true;
}
// Translate a simple OR or AND search clause.
bool SearchDataClauseSimple::toNativeQuery(Rcl::Db &db, void *p)
{
LOGDEB(("SearchDataClauseSimple::toNativeQuery: fld [%s] val [%s] "
"stemlang [%s]\n", m_field.c_str(), m_text.c_str(),
getStemLang().c_str()));
Xapian::Query *qp = (Xapian::Query *)p;
*qp = Xapian::Query();
Xapian::Query::op op;
switch (m_tp) {
case SCLT_AND: op = Xapian::Query::OP_AND; break;
case SCLT_OR: op = Xapian::Query::OP_OR; break;
default:
LOGERR(("SearchDataClauseSimple: bad m_tp %d\n", m_tp));
m_reason = "Internal error";
return false;
}
vector<Xapian::Query> pqueries;
if (!processUserString(db, m_text, m_reason, &pqueries))
return false;
if (pqueries.empty()) {
LOGERR(("SearchDataClauseSimple: resolved to null query\n"));
m_reason = string("Resolved to null query. Term too long ? : [" +
m_text + string("]"));
return false;
}
*qp = Xapian::Query(op, pqueries.begin(), pqueries.end());
if (m_weight != 1.0) {
*qp = Xapian::Query(Xapian::Query::OP_SCALE_WEIGHT, *qp, m_weight);
}
return true;
}
// Translate a FILENAME search clause. This always comes
// from a "filename" search from the gui or recollq. A query language
// "filename:"-prefixed field will not go through here, but through
// the generic field-processing code.
//
// We do not split the entry any more (used to do some crazy thing
// about expanding multiple fragments in the past). We just take the
// value blanks and all and expand this against the indexed unsplit
// file names
bool SearchDataClauseFilename::toNativeQuery(Rcl::Db &db, void *p)
{
Xapian::Query *qp = (Xapian::Query *)p;
*qp = Xapian::Query();
int maxexp = getSoftMaxExp();
if (maxexp == -1)
maxexp = getMaxExp();
vector<string> names;
db.filenameWildExp(m_text, names, maxexp);
*qp = Xapian::Query(Xapian::Query::OP_OR, names.begin(), names.end());
if (m_weight != 1.0) {
*qp = Xapian::Query(Xapian::Query::OP_SCALE_WEIGHT, *qp, m_weight);
}
return true;
}
// Translate a dir: path filtering clause. See comments in .h
bool SearchDataClausePath::toNativeQuery(Rcl::Db &db, void *p)
{
LOGDEB(("SearchDataClausePath::toNativeQuery: [%s]\n", m_text.c_str()));
Xapian::Query *qp = (Xapian::Query *)p;
*qp = Xapian::Query();
if (m_text.empty()) {
LOGERR(("SearchDataClausePath: empty path??\n"));
m_reason = "Empty path ?";
return false;
}
vector<Xapian::Query> orqueries;
if (m_text[0] == '/')
orqueries.push_back(Xapian::Query(wrap_prefix(pathelt_prefix)));
else
m_text = path_tildexpand(m_text);
vector<string> vpath;
stringToTokens(m_text, vpath, "/");
for (vector<string>::const_iterator pit = vpath.begin();
pit != vpath.end(); pit++){
string sterm;
vector<string> exp;
if (!expandTerm(db, m_reason,
SDCM_NOSTEMMING|SDCM_CASESENS|SDCM_DIACSENS,
*pit, exp, sterm, wrap_prefix(pathelt_prefix))) {
return false;
}
LOGDEB0(("SDataPath::toNative: exp size %d\n", exp.size()));
listVector("", exp);
if (exp.size() == 1)
orqueries.push_back(Xapian::Query(exp[0]));
else
orqueries.push_back(Xapian::Query(Xapian::Query::OP_OR,
exp.begin(), exp.end()));
m_curcl += exp.size();
if (m_curcl >= getMaxCl())
return false;
}
*qp = Xapian::Query(Xapian::Query::OP_PHRASE,
orqueries.begin(), orqueries.end());
if (m_weight != 1.0) {
*qp = Xapian::Query(Xapian::Query::OP_SCALE_WEIGHT, *qp, m_weight);
}
return true;
}
// Translate NEAR or PHRASE clause.
bool SearchDataClauseDist::toNativeQuery(Rcl::Db &db, void *p)
{
LOGDEB(("SearchDataClauseDist::toNativeQuery\n"));
Xapian::Query *qp = (Xapian::Query *)p;
*qp = Xapian::Query();
vector<Xapian::Query> pqueries;
// We produce a single phrase out of the user entry then use
// stringToXapianQueries() to lowercase and simplify the phrase
// terms etc. This will result into a single (complex)
// Xapian::Query.
if (m_text.find('\"') != string::npos) {
m_text = neutchars(m_text, "\"");
}
string s = cstr_dquote + m_text + cstr_dquote;
bool useNear = (m_tp == SCLT_NEAR);
if (!processUserString(db, s, m_reason, &pqueries, m_slack, useNear))
return false;
if (pqueries.empty()) {
LOGERR(("SearchDataClauseDist: resolved to null query\n"));
m_reason = string("Resolved to null query. Term too long ? : [" +
m_text + string("]"));
return false;
}
*qp = *pqueries.begin();
if (m_weight != 1.0) {
*qp = Xapian::Query(Xapian::Query::OP_SCALE_WEIGHT, *qp, m_weight);
}
return true;
}
} // Namespace Rcl