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libphutil/src/search/PhutilSearchQueryCompiler.php
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PhutilSearchQueryCompiler.php
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<?php
final class PhutilSearchQueryCompiler
extends Phobject {
private $operators = '+ -><()~*:""&|';
private $query;
private $stemmer;
const OPERATOR_NOT = 'not';
const OPERATOR_AND = 'and';
public function setOperators($operators) {
$this->operators = $operators;
return $this;
}
public function getOperators() {
return $this->operators;
}
public function setQuery($query) {
$this->query = $query;
return $this;
}
public function getQuery() {
return $this->query;
}
public function setStemmer(PhutilSearchStemmer $stemmer) {
$this->stemmer = $stemmer;
return $this;
}
public function getStemmer() {
return $this->stemmer;
}
public function compileQuery() {
$query = $this->getQuery();
$tokens = $this->tokenizeQuery($query);
$result = array();
foreach ($tokens as $token) {
$result[] = $this->renderToken($token);
}
return $this->compileRenderedTokens($result);
}
public function compileLiteralQuery() {
$query = $this->getQuery();
$tokens = $this->tokenizeQuery($query);
$result = array();
foreach ($tokens as $token) {
if (!$token['quoted']) {
continue;
}
$result[] = $this->renderToken($token);
}
return $this->compileRenderedTokens($result);
}
public function compileStemmedQuery() {
$query = $this->getQuery();
$tokens = $this->tokenizeQuery($query);
$result = array();
foreach ($tokens as $token) {
if ($token['quoted']) {
continue;
}
$result[] = $this->renderToken($token, $this->getStemmer());
}
return $this->compileRenderedTokens($result);
}
private function compileRenderedTokens(array $list) {
if (!$list) {
return null;
}
$list = array_unique($list);
return implode(' ', $list);
}
private function tokenizeQuery($query) {
$maximum_bytes = 1024;
$query_bytes = strlen($query);
if ($query_bytes > $maximum_bytes) {
throw new PhutilSearchQueryCompilerSyntaxException(
pht(
'Query is too long (%s bytes, maximum is %s bytes).',
new PhutilNumber($query_bytes),
new PhutilNumber($maximum_bytes)));
}
$query = phutil_utf8v($query);
$length = count($query);
$mode = 'scan';
$current_operator = array();
$current_token = array();
$is_quoted = false;
$tokens = array();
for ($ii = 0; $ii < $length; $ii++) {
$character = $query[$ii];
if ($mode == 'scan') {
if (preg_match('/^\s\z/u', $character)) {
continue;
}
$mode = 'operator';
}
if ($mode == 'operator') {
if (preg_match('/^\s\z/u', $character)) {
continue;
}
if (preg_match('/^[+-]\z/', $character)) {
$current_operator[] = $character;
continue;
}
$mode = 'quote';
}
if ($mode == 'quote') {
if (preg_match('/^"\z/', $character)) {
$is_quoted = true;
$mode = 'token';
continue;
}
$mode = 'token';
}
if ($mode == 'token') {
$capture = false;
$was_quoted = $is_quoted;
if ($is_quoted) {
if (preg_match('/^"\z/', $character)) {
$capture = true;
$mode = 'scan';
$is_quoted = false;
}
} else {
if (preg_match('/^\s\z/u', $character)) {
$capture = true;
$mode = 'scan';
}
if (preg_match('/^"\z/', $character)) {
$capture = true;
$mode = 'token';
$is_quoted = true;
}
}
if ($capture) {
$tokens[] = array(
'operator' => $current_operator,
'quoted' => $was_quoted,
'value' => $current_token,
);
$current_operator = array();
$current_token = array();
continue;
} else {
$current_token[] = $character;
}
}
}
if ($is_quoted) {
throw new PhutilSearchQueryCompilerSyntaxException(
pht(
'Query contains unmatched double quotes.'));
}
if ($mode == 'operator') {
throw new PhutilSearchQueryCompilerSyntaxException(
pht(
'Query contains operator ("%s") with no search term.',
implode('', $current_operator)));
}
$tokens[] = array(
'operator' => $current_operator,
'quoted' => false,
'value' => $current_token,
);
$results = array();
foreach ($tokens as $token) {
$value = implode('', $token['value']);
$operator_string = implode('', $token['operator']);
if (!strlen($value)) {
continue;
}
switch ($operator_string) {
case '-':
$operator = self::OPERATOR_NOT;
break;
case '':
case '+':
$operator = self::OPERATOR_AND;
break;
default:
throw new PhutilSearchQueryCompilerSyntaxException(
pht(
'Query has an invalid sequence of operators ("%s").',
$operator_string));
}
$results[] = array(
'operator' => $operator,
'quoted' => $token['quoted'],
'value' => $value,
);
}
return $results;
}
private function renderToken(
array $token,
PhutilSearchStemmer $stemmer = null) {
$value = $token['value'];
if ($stemmer) {
$value = $stemmer->stemToken($value);
}
$value = $this->quoteToken($value);
$operator = $token['operator'];
$prefix = $this->getOperatorPrefix($operator);
$value = $prefix.$value;
return $value;
}
private function getOperatorPrefix($operator) {
$operators = $this->operators;
switch ($operator) {
case self::OPERATOR_AND:
$prefix = $operators[0];
break;
case self::OPERATOR_NOT:
$prefix = $operators[2];
break;
default:
throw new PhutilSearchQueryCompilerSyntaxException(
pht(
'Unsupported operator prefix "%s".',
$operator));
}
if ($prefix == ' ') {
$prefix = null;
}
return $prefix;
}
private function quoteToken($value) {
$operators = $this->operators;
$open_quote = $this->operators[10];
$close_quote = $this->operators[11];
return $open_quote.$value.$close_quote;
}
}
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