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// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#include "termeditdistancefeature.h"
#include "utils.h"
#include <vespa/searchlib/fef/featurenamebuilder.h>
#include <vespa/searchlib/fef/properties.h>
#include <vespa/vespalib/util/stringfmt.h>
#include <vespa/vespalib/locale/c.h>
#include <vespa/vespalib/util/stash.h>
#include <vespa/log/log.h>
LOG_SETUP(".features.termeditdistance");
namespace search::features {
//---------------------------------------------------------------------------------------------------------------------
// TedCell
//---------------------------------------------------------------------------------------------------------------------
TedCell::TedCell() noexcept :
cost(util::FEATURE_MAX),
numDel(0),
numIns(0),
numSub(0)
{}
TedCell::TedCell(feature_t argCost, uint32_t argNumDel, uint32_t argNumIns, uint32_t argNumSub) noexcept :
cost(argCost),
numDel(argNumDel),
numIns(argNumIns),
numSub(argNumSub)
{}
//---------------------------------------------------------------------------------------------------------------------
// TermEditDistanceConfig
//---------------------------------------------------------------------------------------------------------------------
TermEditDistanceConfig::TermEditDistanceConfig() :
fieldId(search::fef::IllegalHandle),
fieldBegin(0),
fieldEnd(std::numeric_limits<uint32_t>::max()),
costDel(1),
costIns(1),
costSub(1)
{}
//---------------------------------------------------------------------------------------------------------------------
// TermEditDistanceExecutor
//---------------------------------------------------------------------------------------------------------------------
TermEditDistanceExecutor::TermEditDistanceExecutor(const search::fef::IQueryEnvironment &env,
const TermEditDistanceConfig &config) :
search::fef::FeatureExecutor(),
_config(config),
_fieldHandles(),
_termWeights(),
_prevRow(16),
_thisRow(_prevRow.size()),
_md(nullptr)
{
for (uint32_t i = 0; i < env.getNumTerms(); ++i) {
_fieldHandles.push_back(util::getTermFieldHandle(env, i, config.fieldId));
_termWeights.push_back(1.0f);
// XXX was intended to use something like this instead of 1.0f:
// const search::fef::TermData& term = *env.getTerm(i);
// term.isMandatory() ? (feature_t)term.getWeight() : 0.0f
}
}
void
TermEditDistanceExecutor::execute(uint32_t docId)
{
// Determine the number of terms in the field.
uint32_t numQueryTerms = _fieldHandles.size();
uint32_t fieldBegin = _config.fieldBegin;
uint32_t fieldEnd = std::min(_config.fieldEnd,
(uint32_t)inputs().get_number(0));
// _P_A_R_A_N_O_I_A_
TedCell last;
if (fieldBegin < fieldEnd) {
// Construct the cost table.
uint32_t numFieldTerms = fieldEnd - fieldBegin;
if (_prevRow.size() < numFieldTerms + 1) {
_prevRow.resize(numFieldTerms + 1);
_thisRow.resize(_prevRow.size());
}
for (uint32_t field = 0; field <= numFieldTerms; ++field) {
_prevRow[field] = TedCell(field * _config.costIns, 0, field, 0);
}
//LOG(debug, "[ F I E L D S ]");
//logRow(_prevRow, numFieldTerms + 1);
// Iterate over each query term.
for (uint32_t query = 1; query <= numQueryTerms; ++query) {
search::fef::FieldPositionsIterator it; // this is not vaild
// Look for a match of this term.
search::fef::TermFieldHandle handle = _fieldHandles[query - 1];
if (handle != search::fef::IllegalHandle) {
const fef::TermFieldMatchData &tfmd = *_md->resolveTermField(handle);
if (tfmd.getDocId() == docId) {
it = tfmd.getIterator(); // this is now valid
while (it.valid() && it.getPosition() < fieldBegin) {
it.next(); // forward to window
}
}
}
// Predefine the cost of operations on the current term.
feature_t weight = _termWeights[query - 1];
feature_t costDel = _config.costDel * weight;
feature_t costIns = _config.costIns * weight;
feature_t costSub = _config.costSub * weight;
// Iterate over each field term.
_thisRow[0] = TedCell(_prevRow[0].cost + costDel, query, 0, 0);
for (uint32_t field = 1; field <= numFieldTerms; ++field) {
// If the iterator is still valid, we _might_ have a match.
if (it.valid()) {
// If the iterator knows an occurance at this field term, this is a match.
if (it.getPosition() == fieldBegin + (field - 1)) {
_thisRow[field] = _prevRow[field - 1]; // no cost
it.next();
continue; // skip calculations
}
}
// Determine the least-cost operation.
feature_t del = _prevRow[field ].cost + costDel; // cost per previous query term, ie. ignoring this query term.
feature_t ins = _thisRow[field - 1].cost + costIns; // cost per previous field term, ie. insert this query term.
feature_t sub = _prevRow[field - 1].cost + costSub; // cost to replace field term with query term.
feature_t min = std::min(del, std::min(ins, sub));
if (min == del) {
const TedCell &cell = _prevRow[field];
_thisRow[field] = TedCell(del, cell.numDel + 1, cell.numIns, cell.numSub);
}
else if(min == ins) {
const TedCell &cell = _thisRow[field - 1];
_thisRow[field] = TedCell(ins, cell.numDel, cell.numIns + 1, cell.numSub);
}
else {
const TedCell &cell = _prevRow[field - 1];
_thisRow[field] = TedCell(sub, cell.numDel, cell.numIns, cell.numSub + 1);
}
}
_thisRow.swap(_prevRow);
//logRow(_prevRow, numFieldTerms + 1);
}
// Retrieve the bottom-right value.
last = _prevRow[numFieldTerms];
}
outputs().set_number(0, last.cost);
outputs().set_number(1, last.numDel);
outputs().set_number(2, last.numIns);
outputs().set_number(3, last.numSub);
}
void
TermEditDistanceExecutor::handle_bind_match_data(const fef::MatchData &md)
{
_md = &md;
}
void
TermEditDistanceExecutor::logRow(const std::vector<TedCell> &row, size_t numCols)
{
if (LOG_WOULD_LOG(info)) {
vespalib::string str = "[ ";
for (size_t i = 0; i < numCols; ++i) {
str.append(vespalib::make_string("%5.2f", row[i].cost));
if (i < numCols - 1) {
str.append(" ");
}
}
str.append(" ]");
LOG(debug, "%s", str.c_str());
}
}
//---------------------------------------------------------------------------------------------------------------------
// TermEditDistanceBlueprint
//---------------------------------------------------------------------------------------------------------------------
TermEditDistanceBlueprint::TermEditDistanceBlueprint() :
search::fef::Blueprint("termEditDistance"),
_config()
{
// empty
}
void
TermEditDistanceBlueprint::visitDumpFeatures(const search::fef::IIndexEnvironment &,
search::fef::IDumpFeatureVisitor &) const
{
// empty
}
bool
TermEditDistanceBlueprint::setup(const search::fef::IIndexEnvironment &env,
const search::fef::ParameterList ¶ms)
{
_config.fieldId = params[0].asField()->id();
vespalib::string costDel = env.getProperties().lookup(getName(), "costDel").getAt(0);
_config.costDel = costDel.empty() ? 1.0f : vespalib::locale::c::atof(costDel.c_str());
vespalib::string costIns = env.getProperties().lookup(getName(), "costIns").getAt(0);
_config.costIns = costIns.empty() ? 1.0f : vespalib::locale::c::atof(costIns.c_str());
vespalib::string costSub = env.getProperties().lookup(getName(), "costSub").getAt(0);
_config.costSub = costSub.empty() ? 1.0f : vespalib::locale::c::atof(costSub.c_str());
defineInput(vespalib::make_string("fieldLength(%s)", params[0].getValue().c_str()));
describeOutput("out", "Term-wise edit distance.");
describeOutput("del", "Number of deletions performed.");
describeOutput("ins", "Number of insertions performed.");
describeOutput("sub", "Number of substitutions performed.");
return true;
}
search::fef::Blueprint::UP
TermEditDistanceBlueprint::createInstance() const
{
return std::make_unique<TermEditDistanceBlueprint>();
}
search::fef::FeatureExecutor &
TermEditDistanceBlueprint::createExecutor(const search::fef::IQueryEnvironment &env, vespalib::Stash &stash) const
{
return stash.create<TermEditDistanceExecutor>(env, _config);
}
}
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