Show users how fulltext search queries are parsed and executed; don't query stopwords or short tokens

Summary:
Depends on D17670. Fixes T12137. Fixes T12003. Ref T2632.

This shows users a readout of which terms were actually searched for.

This also drops those terms from the query we submit to the backend, dodging the weird behaviors / search engine bugs in T12137.

This might need some design tweaking.

Test Plan: {F4899825}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12137, T12003, T2632

Differential Revision: https://secure.phabricator.com/D17672

resources/celerity/map.php

@@ -103,7 +103,7 @@ return array(
     'rsrc/css/application/releeph/releeph-request-differential-create-dialog.css' => '8d8b92cd',
     'rsrc/css/application/releeph/releeph-request-typeahead.css' => '667a48ae',
     'rsrc/css/application/search/application-search-view.css' => '66ee5d46',
-    'rsrc/css/application/search/search-results.css' => '64ad079a',
+    'rsrc/css/application/search/search-results.css' => 'f87d23ad',
     'rsrc/css/application/slowvote/slowvote.css' => 'a94b7230',
     'rsrc/css/application/tokens/tokens.css' => '3d0f239e',
     'rsrc/css/application/uiexample/example.css' => '528b19de',
@@ -794,7 +794,7 @@ return array(
     'phabricator-phtize' => 'd254d646',
     'phabricator-prefab' => '8d40ae75',
     'phabricator-remarkup-css' => '17c0fb37',
-    'phabricator-search-results-css' => '64ad079a',
+    'phabricator-search-results-css' => 'f87d23ad',
     'phabricator-shaped-request' => '7cbe244b',
     'phabricator-slowvote-css' => 'a94b7230',
     'phabricator-source-code-view-css' => '4383192f',

resources/sql/stopwords_myisam.txt

@@ -0,0 +1,543 @@
+a's
+able
+about
+above
+according
+accordingly
+across
+actually
+after
+afterwards
+again
+against
+ain't
+all
+allow
+allows
+almost
+alone
+along
+already
+also
+although
+always
+am
+among
+amongst
+an
+and
+another
+any
+anybody
+anyhow
+anyone
+anything
+anyway
+anyways
+anywhere
+apart
+appear
+appreciate
+appropriate
+are
+aren't
+around
+as
+aside
+ask
+asking
+associated
+at
+available
+away
+awfully
+be
+became
+because
+become
+becomes
+becoming
+been
+before
+beforehand
+behind
+being
+believe
+below
+beside
+besides
+best
+better
+between
+beyond
+both
+brief
+but
+by
+c'mon
+c's
+came
+can
+can't
+cannot
+cant
+cause
+causes
+certain
+certainly
+changes
+clearly
+co
+com
+come
+comes
+concerning
+consequently
+consider
+considering
+contain
+containing
+contains
+corresponding
+could
+couldn't
+course
+currently
+definitely
+described
+despite
+did
+didn't
+different
+do
+does
+doesn't
+doing
+don't
+done
+down
+downwards
+during
+each
+edu
+eg
+eight
+either
+else
+elsewhere
+enough
+entirely
+especially
+et
+etc
+even
+ever
+every
+everybody
+everyone
+everything
+everywhere
+ex
+exactly
+example
+except
+far
+few
+fifth
+first
+five
+followed
+following
+follows
+for
+former
+formerly
+forth
+four
+from
+further
+furthermore
+get
+gets
+getting
+given
+gives
+go
+goes
+going
+gone
+got
+gotten
+greetings
+had
+hadn't
+happens
+hardly
+has
+hasn't
+have
+haven't
+having
+he
+he's
+hello
+help
+hence
+her
+here
+here's
+hereafter
+hereby
+herein
+hereupon
+hers
+herself
+hi
+him
+himself
+his
+hither
+hopefully
+how
+howbeit
+however
+i'd
+i'll
+i'm
+i've
+ie
+if
+ignored
+immediate
+in
+inasmuch
+inc
+indeed
+indicate
+indicated
+indicates
+inner
+insofar
+instead
+into
+inward
+is
+isn't
+it
+it'd
+it'll
+it's
+its
+itself
+just
+keep
+keeps
+kept
+know
+known
+knows
+last
+lately
+later
+latter
+latterly
+least
+less
+lest
+let
+let's
+like
+liked
+likely
+little
+look
+looking
+looks
+ltd
+mainly
+many
+may
+maybe
+me
+mean
+meanwhile
+merely
+might
+more
+moreover
+most
+mostly
+much
+must
+my
+myself
+name
+namely
+nd
+near
+nearly
+necessary
+need
+needs
+neither
+never
+nevertheless
+new
+next
+nine
+no
+nobody
+non
+none
+noone
+nor
+normally
+not
+nothing
+novel
+now
+nowhere
+obviously
+of
+off
+often
+oh
+ok
+okay
+old
+on
+once
+one
+ones
+only
+onto
+or
+other
+others
+otherwise
+ought
+our
+ours
+ourselves
+out
+outside
+over
+overall
+own
+particular
+particularly
+per
+perhaps
+placed
+please
+plus
+possible
+presumably
+probably
+provides
+que
+quite
+qv
+rather
+rd
+re
+really
+reasonably
+regarding
+regardless
+regards
+relatively
+respectively
+right
+said
+same
+saw
+say
+saying
+says
+second
+secondly
+see
+seeing
+seem
+seemed
+seeming
+seems
+seen
+self
+selves
+sensible
+sent
+serious
+seriously
+seven
+several
+shall
+she
+should
+shouldn't
+since
+six
+so
+some
+somebody
+somehow
+someone
+something
+sometime
+sometimes
+somewhat
+somewhere
+soon
+sorry
+specified
+specify
+specifying
+still
+sub
+such
+sup
+sure
+t's
+take
+taken
+tell
+tends
+th
+than
+thank
+thanks
+thanx
+that
+that's
+thats
+the
+their
+theirs
+them
+themselves
+then
+thence
+there
+there's
+thereafter
+thereby
+therefore
+therein
+theres
+thereupon
+these
+they
+they'd
+they'll
+they're
+they've
+think
+third
+this
+thorough
+thoroughly
+those
+though
+three
+through
+throughout
+thru
+thus
+to
+together
+too
+took
+toward
+towards
+tried
+tries
+truly
+try
+trying
+twice
+two
+un
+under
+unfortunately
+unless
+unlikely
+until
+unto
+up
+upon
+us
+use
+used
+useful
+uses
+using
+usually
+value
+various
+very
+via
+viz
+vs
+want
+wants
+was
+wasn't
+way
+we
+we'd
+we'll
+we're
+we've
+welcome
+well
+went
+were
+weren't
+what
+what's
+whatever
+when
+whence
+whenever
+where
+where's
+whereafter
+whereas
+whereby
+wherein
+whereupon
+wherever
+whether
+which
+while
+whither
+who
+who's
+whoever
+whole
+whom
+whose
+why
+will
+willing
+wish
+with
+within
+without
+won't
+wonder
+would
+wouldn't
+yes
+yet
+you
+you'd
+you'll
+you're
+you've
+your
+yours
+yourself
+yourselves
+zero

src/__phutil_library_map__.php

@@ -2844,7 +2844,9 @@ phutil_register_library_map(array(
     'PhabricatorFulltextEngineExtensionModule' => 'applications/search/index/PhabricatorFulltextEngineExtensionModule.php',
     'PhabricatorFulltextIndexEngineExtension' => 'applications/search/engineextension/PhabricatorFulltextIndexEngineExtension.php',
     'PhabricatorFulltextInterface' => 'applications/search/interface/PhabricatorFulltextInterface.php',
+    'PhabricatorFulltextResultSet' => 'applications/search/query/PhabricatorFulltextResultSet.php',
     'PhabricatorFulltextStorageEngine' => 'applications/search/fulltextstorage/PhabricatorFulltextStorageEngine.php',
+    'PhabricatorFulltextToken' => 'applications/search/query/PhabricatorFulltextToken.php',
     'PhabricatorFundApplication' => 'applications/fund/application/PhabricatorFundApplication.php',
     'PhabricatorGDSetupCheck' => 'applications/config/check/PhabricatorGDSetupCheck.php',
     'PhabricatorGarbageCollector' => 'infrastructure/daemon/garbagecollector/PhabricatorGarbageCollector.php',
@@ -8005,7 +8007,9 @@ phutil_register_library_map(array(
     'PhabricatorFulltextEngineExtension' => 'Phobject',
     'PhabricatorFulltextEngineExtensionModule' => 'PhabricatorConfigModule',
     'PhabricatorFulltextIndexEngineExtension' => 'PhabricatorIndexEngineExtension',
+    'PhabricatorFulltextResultSet' => 'Phobject',
     'PhabricatorFulltextStorageEngine' => 'Phobject',
+    'PhabricatorFulltextToken' => 'Phobject',
     'PhabricatorFundApplication' => 'PhabricatorApplication',
     'PhabricatorGDSetupCheck' => 'PhabricatorSetupCheck',
     'PhabricatorGarbageCollector' => 'Phobject',

src/applications/search/engine/PhabricatorApplicationSearchEngine.php

@@ -978,9 +978,15 @@ abstract class PhabricatorApplicationSearchEngine extends Phobject {
       $objects = $query->executeWithCursorPager($pager);
     }
 
+    $this->didExecuteQuery($query);
+
     return $objects;
   }
 
+  protected function didExecuteQuery(PhabricatorPolicyAwareQuery $query) {
+    return;
+  }
+
 
 /* -(  Rendering  )---------------------------------------------------------- */
 

src/applications/search/fulltextstorage/PhabricatorFulltextStorageEngine.php

@@ -101,4 +101,8 @@ abstract class PhabricatorFulltextStorageEngine extends Phobject {
   public function initIndex() {}
 
 
+  public function getFulltextTokens() {
+    return array();
+  }
+
 }

src/applications/search/fulltextstorage/PhabricatorMySQLFulltextStorageEngine.php

@@ -3,6 +3,9 @@
 final class PhabricatorMySQLFulltextStorageEngine
   extends PhabricatorFulltextStorageEngine {
 
+  private $fulltextTokens = array();
+  private $engineLimits;
+
   public function getEngineIdentifier() {
     return 'mysql';
   }
@@ -203,8 +206,64 @@ final class PhabricatorMySQLFulltextStorageEngine
     $title_field = PhabricatorSearchDocumentFieldType::FIELD_TITLE;
     $title_boost = 1024;
 
+    $stemmer = new PhutilSearchStemmer();
+
     $raw_query = $query->getParameter('query');
-    $compiled_query = $this->compileQuery($raw_query);
+    $raw_query = trim($raw_query);
+    if (strlen($raw_query)) {
+      $compiler = PhabricatorSearchDocument::newQueryCompiler()
+        ->setStemmer($stemmer);
+
+      $tokens = $compiler->newTokens($raw_query);
+
+      list($min_length, $stopword_list) = $this->getEngineLimits($conn);
+
+      // Process all the parts of the user's query so we can show them which
+      // parts we searched for and which ones we ignored.
+      $fulltext_tokens = array();
+      foreach ($tokens as $key => $token) {
+        $fulltext_token = id(new PhabricatorFulltextToken())
+          ->setToken($token);
+
+        $fulltext_tokens[$key] = $fulltext_token;
+
+        $value = $token->getValue();
+        if (phutil_utf8_strlen($value) < $min_length) {
+          $fulltext_token->setIsShort(true);
+          continue;
+        }
+
+        if (isset($stopword_list[phutil_utf8_strtolower($value)])) {
+          $fulltext_token->setIsStopword(true);
+          continue;
+        }
+      }
+      $this->fulltextTokens = $fulltext_tokens;
+
+      // Remove tokens which aren't queryable from the query. This is mostly
+      // a workaround for the peculiar behaviors described in T12137.
+      foreach ($this->fulltextTokens as $key => $fulltext_token) {
+        if (!$fulltext_token->isQueryable()) {
+          unset($tokens[$key]);
+        }
+      }
+
+      if (!$tokens) {
+        throw new PhutilSearchQueryCompilerSyntaxException(
+          pht(
+            'All of your search terms are too short or too common to '.
+            'appear in the search index. Search for longer or more '.
+            'distinctive terms.'));
+      }
+
+      $queries = array();
+      $queries[] = $compiler->compileLiteralQuery($tokens);
+      $queries[] = $compiler->compileStemmedQuery($tokens);
+      $compiled_query = implode(' ', array_filter($queries));
+    } else {
+      $compiled_query = null;
+    }
+
     if (strlen($compiled_query)) {
       $select[] = qsprintf(
         $conn,
@@ -394,21 +453,6 @@ final class PhabricatorMySQLFulltextStorageEngine
     return $sql;
   }
 
-  private function compileQuery($raw_query) {
-    $stemmer = new PhutilSearchStemmer();
-
-    $compiler = PhabricatorSearchDocument::newQueryCompiler()
-      ->setStemmer($stemmer);
-
-    $tokens = $compiler->newTokens($raw_query);
-
-    $queries = array();
-    $queries[] = $compiler->compileLiteralQuery($tokens);
-    $queries[] = $compiler->compileStemmedQuery($tokens);
-
-    return implode(' ', array_filter($queries));
-  }
-
   public function indexExists() {
     return true;
   }
@@ -417,4 +461,56 @@ final class PhabricatorMySQLFulltextStorageEngine
     return false;
   }
 
+  public function getFulltextTokens() {
+    return $this->fulltextTokens;
+  }
+
+  private function getEngineLimits(AphrontDatabaseConnection $conn) {
+    if ($this->engineLimits === null) {
+      $this->engineLimits = $this->newEngineLimits($conn);
+    }
+    return $this->engineLimits;
+  }
+
+  private function newEngineLimits(AphrontDatabaseConnection $conn) {
+    $result = queryfx_one(
+      $conn,
+      'SELECT
+        @@innodb_ft_min_token_size innodb_max,
+        @@ft_min_word_len myisam_max,
+        @@ft_stopword_file myisam_stopwords');
+
+    if ($result['innodb_max']) {
+      $min_len = $result['innodb_max'];
+      $stopwords = queryfx_all(
+        $conn,
+        'SELECT * FROM INFORMATION_SCHEMA.INNODB_FT_DEFAULT_STOPWORD');
+      $stopwords = ipull($stopwords, 'value');
+      $stopwords = array_fuse($stopwords);
+    } else {
+      $min_len = $result['myisam_max'];
+
+      $file = $result['myisam_stopwords'];
+      if (preg_match('(/resources/sql/stopwords\.txt\z)', $file)) {
+        // If this is set to something that looks like the Phabricator
+        // stopword file, read that.
+        $file = 'stopwords.txt';
+      } else {
+        // Otherwise, just use the default stopwords. This might be wrong
+        // but we can't read the actual value dynamically and reading
+        // whatever file the variable is set to could be a big headache
+        // to get right from a security perspective.
+        $file = 'stopwords_myisam.txt';
+      }
+
+      $root = dirname(phutil_get_library_root('phabricator'));
+      $data = Filesystem::readFile($root.'/resources/sql/'.$file);
+      $stopwords = explode("\n", $data);
+      $stopwords = array_filter($stopwords);
+      $stopwords = array_fuse($stopwords);
+    }
+
+    return array($min_len, $stopwords);
+  }
+
 }

src/applications/search/query/PhabricatorFulltextResultSet.php

@@ -0,0 +1,26 @@
+<?php
+
+final class PhabricatorFulltextResultSet extends Phobject {
+
+  private $phids;
+  private $fulltextTokens;
+
+  public function setPHIDs($phids) {
+    $this->phids = $phids;
+    return $this;
+  }
+
+  public function getPHIDs() {
+    return $this->phids;
+  }
+
+  public function setFulltextTokens($fulltext_tokens) {
+    $this->fulltextTokens = $fulltext_tokens;
+    return $this;
+  }
+
+  public function getFulltextTokens() {
+    return $this->fulltextTokens;
+  }
+
+}

src/applications/search/query/PhabricatorFulltextToken.php

@@ -0,0 +1,88 @@
+<?php
+
+final class PhabricatorFulltextToken extends Phobject {
+
+  private $token;
+  private $isShort;
+  private $isStopword;
+
+  public function setToken(PhutilSearchQueryToken $token) {
+    $this->token = $token;
+    return $this;
+  }
+
+  public function getToken() {
+    return $this->token;
+  }
+
+  public function isQueryable() {
+    return !$this->getIsShort() && !$this->getIsStopword();
+  }
+
+  public function setIsShort($is_short) {
+    $this->isShort = $is_short;
+    return $this;
+  }
+
+  public function getIsShort() {
+    return $this->isShort;
+  }
+
+  public function setIsStopword($is_stopword) {
+    $this->isStopword = $is_stopword;
+    return $this;
+  }
+
+  public function getIsStopword() {
+    return $this->isStopword;
+  }
+
+  public function newTag() {
+    $token = $this->getToken();
+
+    $tip = null;
+    $icon = null;
+
+    if ($this->getIsShort()) {
+      $shade = PHUITagView::COLOR_GREY;
+      $tip = pht('Ignored Short Word');
+    } else if ($this->getIsStopword()) {
+      $shade = PHUITagView::COLOR_GREY;
+      $tip = pht('Ignored Common Word');
+    } else {
+      $operator = $token->getOperator();
+      switch ($operator) {
+        case PhutilSearchQueryCompiler::OPERATOR_NOT:
+          $shade = PHUITagView::COLOR_RED;
+          $icon = 'fa-minus';
+          break;
+        default:
+          $shade = PHUITagView::COLOR_BLUE;
+          break;
+      }
+    }
+
+    $tag = id(new PHUITagView())
+      ->setType(PHUITagView::TYPE_SHADE)
+      ->setShade($shade)
+      ->setName($token->getValue());
+
+    if ($tip !== null) {
+      Javelin::initBehavior('phabricator-tooltips');
+
+      $tag
+        ->addSigil('has-tooltip')
+        ->setMetadata(
+          array(
+            'tip' => $tip,
+          ));
+    }
+
+    if ($icon !== null) {
+      $tag->setIcon($icon);
+    }
+
+    return $tag;
+  }
+
+}

src/applications/search/query/PhabricatorSearchApplicationSearchEngine.php

@@ -3,6 +3,8 @@
 final class PhabricatorSearchApplicationSearchEngine
   extends PhabricatorApplicationSearchEngine {
 
+  private $resultSet;
+
   public function getResultTypeDescription() {
     return pht('Fulltext Search Results');
   }
@@ -243,6 +245,9 @@ final class PhabricatorSearchApplicationSearchEngine
     PhabricatorSavedQuery $query,
     array $handles) {
 
+    $result_set = $this->resultSet;
+    $fulltext_tokens = $result_set->getFulltextTokens();
+
     $viewer = $this->requireViewer();
     $list = new PHUIObjectItemListView();
     $list->setNoDataString(pht('No results found.'));
@@ -263,7 +268,28 @@ final class PhabricatorSearchApplicationSearchEngine
       }
     }
 
+    $fulltext_view = null;
+    if ($fulltext_tokens) {
+      require_celerity_resource('phabricator-search-results-css');
+
+      $fulltext_view = array();
+      foreach ($fulltext_tokens as $token) {
+        $fulltext_view[] = $token->newTag();
+      }
+      $fulltext_view = phutil_tag(
+        'div',
+        array(
+          'class' => 'phui-fulltext-tokens',
+        ),
+        array(
+          pht('Searched For:'),
+          ' ',
+          $fulltext_view,
+        ));
+    }
+
     $result = new PhabricatorApplicationSearchResultView();
+    $result->setContent($fulltext_view);
     $result->setObjectList($list);
 
     return $result;
@@ -280,4 +306,8 @@ final class PhabricatorSearchApplicationSearchEngine
     return $owner_phids;
   }
 
+  protected function didExecuteQuery(PhabricatorPolicyAwareQuery $query) {
+    $this->resultSet = $query->getFulltextResultSet();
+  }
+
 }

src/applications/search/query/PhabricatorSearchDocumentQuery.php

@@ -6,6 +6,7 @@ final class PhabricatorSearchDocumentQuery
   private $savedQuery;
   private $objectCapabilities;
   private $unfilteredOffset;
+  private $fulltextResultSet;
 
   public function withSavedQuery(PhabricatorSavedQuery $query) {
     $this->savedQuery = $query;
@@ -25,8 +26,17 @@ final class PhabricatorSearchDocumentQuery
     return $this->getRequiredCapabilities();
   }
 
+  public function getFulltextResultSet() {
+    if (!$this->fulltextResultSet) {
+      throw new PhutilInvalidStateException('execute');
+    }
+
+    return $this->fulltextResultSet;
+  }
+
   protected function willExecute() {
     $this->unfilteredOffset = 0;
+    $this->fulltextResultSet = null;
   }
 
   protected function loadPage() {
@@ -39,8 +49,10 @@ final class PhabricatorSearchDocumentQuery
       ->setParameter('offset', $this->unfilteredOffset)
       ->setParameter('limit', $this->getRawResultLimit());
 
-    $phids = PhabricatorSearchService::executeSearch($query);
+    $result_set = PhabricatorSearchService::newResultSet($query, $this);
+    $phids = $result_set->getPHIDs();
 
+    $this->fulltextResultSet = $result_set;
     $this->unfilteredOffset += count($phids);
 
     $handles = id(new PhabricatorHandleQuery())

src/infrastructure/cluster/search/PhabricatorSearchService.php

@@ -245,14 +245,25 @@ class PhabricatorSearchService
    * @throws PhutilAggregateException
    */
   public static function executeSearch(PhabricatorSavedQuery $query) {
+    $result_set = self::newResultSet($query);
+    return $result_set->getPHIDs();
+  }
+
+  public static function newResultSet(PhabricatorSavedQuery $query) {
     $exceptions = array();
     // try all services until one succeeds
     foreach (self::getAllServices() as $service) {
+      if (!$service->isReadable()) {
+        continue;
+      }
+
       try {
         $engine = $service->getEngine();
-        $res = $engine->executeSearch($query);
-        // return immediately if we get results
-        return $res;
+        $phids = $engine->executeSearch($query);
+
+        return id(new PhabricatorFulltextResultSet())
+          ->setPHIDs($phids)
+          ->setFulltextTokens($engine->getFulltextTokens());
       } catch (PhutilSearchQueryCompilerSyntaxException $ex) {
         // If there's a query compilation error, return it directly to the
         // user: they issued a query with bad syntax.

webroot/rsrc/css/application/search/search-results.css

@@ -16,3 +16,16 @@
   font-weight: normal;
   color: #000;
 }
+
+.phui-fulltext-tokens {
+  margin: 16px 8px;
+  font-weight: bold;
+}
+
+.phui-fulltext-tokens .phui-tag-view {
+  margin: 0 2px;
+}
+
+.phui-fulltext-tokens .phui-tag-view.phui-tag-shade-grey {
+  opacity: 0.5;
+}