Truncate long source lines in Paste search result list snippets

Summary:
An attempt to resolve T9600.

- `PhabricatorPasteQuery` builds truncated snippet when requested using `needSnippet()`.
- `PhabricatorPasteSearchEngine` uses Paste snippet istead of content.
- `PhabricatorSourceCodeView` accepts truncated source and type instead of line limit.

Test Plan: Generated some content for Paste application and also added huge JSON oneliner. Checked Paste application pages in browser.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin

Maniphest Tasks: T9600

Differential Revision: https://secure.phabricator.com/D14313

src/__phutil_library_map__.php

@@ -2552,6 +2552,7 @@ phutil_register_library_map(array(
     'PhabricatorPasteRemarkupRule' => 'applications/paste/remarkup/PhabricatorPasteRemarkupRule.php',
     'PhabricatorPasteSchemaSpec' => 'applications/paste/storage/PhabricatorPasteSchemaSpec.php',
     'PhabricatorPasteSearchEngine' => 'applications/paste/query/PhabricatorPasteSearchEngine.php',
+    'PhabricatorPasteSnippet' => 'applications/paste/snippet/PhabricatorPasteSnippet.php',
     'PhabricatorPasteTestDataGenerator' => 'applications/paste/lipsum/PhabricatorPasteTestDataGenerator.php',
     'PhabricatorPasteTransaction' => 'applications/paste/storage/PhabricatorPasteTransaction.php',
     'PhabricatorPasteTransactionComment' => 'applications/paste/storage/PhabricatorPasteTransactionComment.php',
@@ -6633,6 +6634,7 @@ phutil_register_library_map(array(
     'PhabricatorPasteRemarkupRule' => 'PhabricatorObjectRemarkupRule',
     'PhabricatorPasteSchemaSpec' => 'PhabricatorConfigSchemaSpec',
     'PhabricatorPasteSearchEngine' => 'PhabricatorApplicationSearchEngine',
+    'PhabricatorPasteSnippet' => 'Phobject',
     'PhabricatorPasteTestDataGenerator' => 'PhabricatorTestDataGenerator',
     'PhabricatorPasteTransaction' => 'PhabricatorApplicationTransaction',
     'PhabricatorPasteTransactionComment' => 'PhabricatorApplicationTransactionComment',

src/applications/paste/controller/PhabricatorPasteController.php

@@ -39,13 +39,11 @@ abstract class PhabricatorPasteController extends PhabricatorController {
 
   public function buildSourceCodeView(
     PhabricatorPaste $paste,
-    $max_lines = null,
     $highlights = array()) {
 
     $lines = phutil_split_lines($paste->getContent());
 
     return id(new PhabricatorSourceCodeView())
-      ->setLimit($max_lines)
       ->setLines($lines)
       ->setHighlights($highlights)
       ->setURI(new PhutilURI($paste->getURI()));

src/applications/paste/controller/PhabricatorPasteViewController.php

@@ -56,10 +56,7 @@ final class PhabricatorPasteViewController extends PhabricatorPasteController {
       ->setHeader($header)
       ->addPropertyList($properties);
 
-    $source_code = $this->buildSourceCodeView(
-      $paste,
-      null,
-      $this->highlightMap);
+    $source_code = $this->buildSourceCodeView($paste, $this->highlightMap);
 
     require_celerity_resource('paste-css');
     $source_code = phutil_tag(

src/applications/paste/query/PhabricatorPasteQuery.php

@@ -10,6 +10,7 @@ final class PhabricatorPasteQuery
 
   private $needContent;
   private $needRawContent;
+  private $needSnippets;
   private $languages;
   private $includeNoLanguage;
   private $dateCreatedAfter;
@@ -47,6 +48,11 @@ final class PhabricatorPasteQuery
     return $this;
   }
 
+  public function needSnippets($need_snippets) {
+    $this->needSnippets = $need_snippets;
+    return $this;
+  }
+
   public function withLanguages(array $languages) {
     $this->includeNoLanguage = false;
     foreach ($languages as $key => $language) {
@@ -91,6 +97,10 @@ final class PhabricatorPasteQuery
       $pastes = $this->loadContent($pastes);
     }
 
+    if ($this->needSnippets) {
+      $pastes = $this->loadSnippets($pastes);
+    }
+
     return $pastes;
   }
 
@@ -166,6 +176,17 @@ final class PhabricatorPasteQuery
       ));
   }
 
+  private function getSnippetCacheKey(PhabricatorPaste $paste) {
+    return implode(
+      ':',
+      array(
+        'P'.$paste->getID(),
+        $paste->getFilePHID(),
+        $paste->getLanguage(),
+        'snippet',
+      ));
+  }
+
   private function loadRawContent(array $pastes) {
     $file_phids = mpull($pastes, 'getFilePHID');
     $files = id(new PhabricatorFileQuery())
@@ -250,13 +271,108 @@ final class PhabricatorPasteQuery
     return $pastes;
   }
 
-  private function buildContent(PhabricatorPaste $paste) {
-    $language = $paste->getLanguage();
-    $source = $paste->getRawContent();
+  private function loadSnippets(array $pastes) {
+    $cache = new PhabricatorKeyValueDatabaseCache();
 
+    $cache = new PhutilKeyValueCacheProfiler($cache);
+    $cache->setProfiler(PhutilServiceProfiler::getInstance());
+
+    $keys = array();
+    foreach ($pastes as $paste) {
+      $keys[] = $this->getSnippetCacheKey($paste);
+    }
+
+    $caches = $cache->getKeys($keys);
+
+    $need_raw = array();
+    $have_cache = array();
+    foreach ($pastes as $paste) {
+      $key = $this->getSnippetCacheKey($paste);
+      if (isset($caches[$key])) {
+        $snippet_data = phutil_json_decode($caches[$key], true);
+        $snippet = new PhabricatorPasteSnippet(
+          phutil_safe_html($snippet_data['content']),
+          $snippet_data['type']);
+        $paste->attachSnippet($snippet);
+        $have_cache[$paste->getPHID()] = true;
+      } else {
+        $need_raw[$key] = $paste;
+      }
+    }
+
+    if (!$need_raw) {
+      return $pastes;
+    }
+
+    $write_data = array();
+
+    $have_raw = $this->loadRawContent($need_raw);
+    $have_raw = mpull($have_raw, null, 'getPHID');
+    foreach ($pastes as $key => $paste) {
+      $paste_phid = $paste->getPHID();
+      if (isset($have_cache[$paste_phid])) {
+        continue;
+      }
+
+      if (empty($have_raw[$paste_phid])) {
+        unset($pastes[$key]);
+        continue;
+      }
+
+      $snippet = $this->buildSnippet($paste);
+      $paste->attachSnippet($snippet);
+      $snippet_data = array(
+        'content' => (string)$snippet->getContent(),
+        'type' => (string)$snippet->getType(),
+      );
+      $write_data[$this->getSnippetCacheKey($paste)] = phutil_json_encode(
+        $snippet_data);
+    }
+
+    if ($write_data) {
+      $cache->setKeys($write_data);
+    }
+
+    return $pastes;
+  }
+
+  private function buildContent(PhabricatorPaste $paste) {
+    return $this->highlightSource(
+      $paste->getRawContent(),
+      $paste->getTitle(),
+      $paste->getLanguage());
+  }
+
+  private function buildSnippet(PhabricatorPaste $paste) {
+    $snippet_type = PhabricatorPasteSnippet::FULL;
+    $snippet = $paste->getRawContent();
+
+    if (strlen($snippet) > 1024) {
+      $snippet_type = PhabricatorPasteSnippet::FIRST_BYTES;
+      $snippet = id(new PhutilUTF8StringTruncator())
+        ->setMaximumBytes(1024)
+        ->setTerminator('')
+        ->truncateString($snippet);
+    }
+
+    $lines = phutil_split_lines($snippet);
+    if (count($lines) > 5) {
+      $snippet_type = PhabricatorPasteSnippet::FIRST_LINES;
+      $snippet = implode('', array_slice($lines, 0, 5));
+    }
+
+    return new PhabricatorPasteSnippet(
+      $this->highlightSource(
+        $snippet,
+        $paste->getTitle(),
+        $paste->getLanguage()),
+      $snippet_type);
+  }
+
+  private function highlightSource($source, $title, $language) {
       if (empty($language)) {
         return PhabricatorSyntaxHighlighter::highlightWithFilename(
-        $paste->getTitle(),
+          $title,
           $source);
       } else {
         return PhabricatorSyntaxHighlighter::highlightWithLanguage(

src/applications/paste/query/PhabricatorPasteSearchEngine.php

@@ -13,7 +13,7 @@ final class PhabricatorPasteSearchEngine
 
   public function newQuery() {
     return id(new PhabricatorPasteQuery())
-      ->needContent(true);
+      ->needSnippets(true);
   }
 
   protected function buildQueryFromParameters(array $map) {
@@ -136,11 +136,15 @@ final class PhabricatorPasteSearchEngine
       $created = phabricator_date($paste->getDateCreated(), $viewer);
       $author = $handles[$paste->getAuthorPHID()]->renderLink();
 
-      $lines = phutil_split_lines($paste->getContent());
+      $snippet_type = $paste->getSnippet()->getType();
+      $lines = phutil_split_lines($paste->getSnippet()->getContent());
 
       $preview = id(new PhabricatorSourceCodeView())
-        ->setLimit(5)
         ->setLines($lines)
+        ->setTruncatedFirstBytes(
+          $snippet_type == PhabricatorPasteSnippet::FIRST_BYTES)
+        ->setTruncatedFirstLines(
+          $snippet_type == PhabricatorPasteSnippet::FIRST_LINES)
         ->setURI(new PhutilURI($paste->getURI()));
 
       $source_code = phutil_tag(

src/applications/paste/snippet/PhabricatorPasteSnippet.php

@@ -0,0 +1,24 @@
+<?php
+
+final class PhabricatorPasteSnippet extends Phobject {
+
+  const FULL = 'full';
+  const FIRST_LINES = 'first_lines';
+  const FIRST_BYTES = 'first_bytes';
+
+  private $content;
+  private $type;
+
+  public function __construct($content, $type) {
+    $this->content = $content;
+    $this->type = $type;
+  }
+
+  public function getContent() {
+    return $this->content;
+  }
+
+  public function getType() {
+    return $this->type;
+  }
+}

src/applications/paste/storage/PhabricatorPaste.php

@@ -28,6 +28,7 @@ final class PhabricatorPaste extends PhabricatorPasteDAO
 
   private $content = self::ATTACHABLE;
   private $rawContent = self::ATTACHABLE;
+  private $snippet = self::ATTACHABLE;
 
   public static function initializeNewPaste(PhabricatorUser $actor) {
     $app = id(new PhabricatorApplicationQuery())
@@ -135,6 +136,15 @@ final class PhabricatorPaste extends PhabricatorPasteDAO
     return $this;
   }
 
+  public function getSnippet() {
+    return $this->assertAttached($this->snippet);
+  }
+
+  public function attachSnippet(PhabricatorPasteSnippet $snippet) {
+    $this->snippet = $snippet;
+    return $this;
+  }
+
 /* -(  PhabricatorSubscribableInterface  )----------------------------------- */
 
 

src/view/layout/PhabricatorSourceCodeView.php

@@ -3,15 +3,11 @@
 final class PhabricatorSourceCodeView extends AphrontView {
 
   private $lines;
-  private $limit;
   private $uri;
   private $highlights = array();
   private $canClickHighlight = true;
-
-  public function setLimit($limit) {
-    $this->limit = $limit;
-    return $this;
-  }
+  private $truncatedFirstBytes = false;
+  private $truncatedFirstLines = false;
 
   public function setLines(array $lines) {
     $this->lines = $lines;
@@ -33,6 +29,16 @@ final class PhabricatorSourceCodeView extends AphrontView {
     return $this;
   }
 
+  public function setTruncatedFirstBytes($truncated_first_bytes) {
+    $this->truncatedFirstBytes = $truncated_first_bytes;
+    return $this;
+  }
+
+  public function setTruncatedFirstLines($truncated_first_lines) {
+    $this->truncatedFirstLines = $truncated_first_lines;
+    return $this;
+  }
+
   public function render() {
     require_celerity_resource('phabricator-source-code-view-css');
     require_celerity_resource('syntax-highlighting-css');
@@ -46,24 +52,31 @@ final class PhabricatorSourceCodeView extends AphrontView {
 
     $rows = array();
 
-    foreach ($this->lines as $line) {
-      $hit_limit = $this->limit &&
-                   ($line_number == $this->limit) &&
-                   (count($this->lines) != $this->limit);
-
-      if ($hit_limit) {
-        $content_number = '';
-        $content_line = phutil_tag(
+    $lines = $this->lines;
+    if ($this->truncatedFirstLines) {
+      $lines[] = phutil_tag(
           'span',
           array(
             'class' => 'c',
           ),
           pht('...'));
-      } else {
-        $content_number = $line_number;
+    } else if ($this->truncatedFirstBytes) {
+      $last_key = last_key($lines);
+      $lines[$last_key] = hsprintf(
+        '%s%s',
+        $lines[$last_key],
+        phutil_tag(
+          'span',
+          array(
+            'class' => 'c',
+          ),
+          pht('...')));
+    }
+
+    foreach ($lines as $line) {
+
       // NOTE: See phabricator-oncopy behavior.
       $content_line = hsprintf("\xE2\x80\x8B%s", $line);
-      }
 
       $row_attributes = array();
       if (isset($this->highlights[$line_number])) {
@@ -106,10 +119,6 @@ final class PhabricatorSourceCodeView extends AphrontView {
             $content_line),
           ));
 
-      if ($hit_limit) {
-        break;
-      }
-
       $line_number++;
     }