Add a "SymbolEngine" to support top-level ref resolution by symbol

Summary:
Ref T13490. I'm continuing to move toward modernizing "amend", which needs to load some objects by symbol at top level.

Add an API to support this.

Test Plan: Added an API caller to "arc inspect", ran it and hit the new code. Things seemed to work.

Maniphest Tasks: T13490

Differential Revision: https://secure.phabricator.com/D21094

src/__phutil_library_map__.php

@@ -437,6 +437,7 @@ phutil_register_library_map(array(
     'ArcanistSubversionAPI' => 'repository/api/ArcanistSubversionAPI.php',
     'ArcanistSubversionWorkingCopy' => 'workingcopy/ArcanistSubversionWorkingCopy.php',
     'ArcanistSummaryLintRenderer' => 'lint/renderer/ArcanistSummaryLintRenderer.php',
+    'ArcanistSymbolEngine' => 'ref/symbol/ArcanistSymbolEngine.php',
     'ArcanistSymbolRef' => 'ref/symbol/ArcanistSymbolRef.php',
     'ArcanistSyntaxErrorXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistSyntaxErrorXHPASTLinterRule.php',
     'ArcanistSystemConfigurationSource' => 'config/source/ArcanistSystemConfigurationSource.php',
@@ -1381,7 +1382,10 @@ phutil_register_library_map(array(
     'ArcanistReusedIteratorXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistRevertWorkflow' => 'ArcanistWorkflow',
     'ArcanistRevisionCommitMessageHardpointQuery' => 'ArcanistWorkflowHardpointQuery',
-    'ArcanistRevisionRef' => 'ArcanistRef',
+    'ArcanistRevisionRef' => array(
+      'ArcanistRef',
+      'ArcanistDisplayRefInterface',
+    ),
     'ArcanistRevisionRefSource' => 'Phobject',
     'ArcanistRevisionSymbolHardpointQuery' => 'ArcanistWorkflowHardpointQuery',
     'ArcanistRevisionSymbolRef' => 'ArcanistSymbolRef',
@@ -1417,6 +1421,7 @@ phutil_register_library_map(array(
     'ArcanistSubversionAPI' => 'ArcanistRepositoryAPI',
     'ArcanistSubversionWorkingCopy' => 'ArcanistWorkingCopy',
     'ArcanistSummaryLintRenderer' => 'ArcanistLintRenderer',
+    'ArcanistSymbolEngine' => 'Phobject',
     'ArcanistSymbolRef' => 'ArcanistRef',
     'ArcanistSyntaxErrorXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistSystemConfigurationSource' => 'ArcanistFilesystemConfigurationSource',

src/ref/commit/ArcanistGitCommitSymbolCommitHardpointQuery.php

@@ -76,6 +76,17 @@ final class ArcanistGitCommitSymbolCommitHardpointQuery
       $results[$key] = $hash_map[$symbol];
     }
 
+    foreach ($results as $key => $result) {
+      if ($result === null) {
+        continue;
+      }
+
+      $ref = id(new ArcanistCommitRef())
+        ->setCommitHash($result);
+
+      $results[$key] = $ref;
+    }
+
     yield $this->yieldMap($results);
   }
 

src/ref/revision/ArcanistRevisionRef.php

@@ -1,7 +1,9 @@
 <?php
 
 final class ArcanistRevisionRef
-  extends ArcanistRef {
+  extends ArcanistRef
+  implements
+    ArcanistDisplayRefInterface {
 
   const HARDPOINT_COMMITMESSAGE = 'ref.revision.commitmessage';
 
@@ -77,4 +79,12 @@ final class ArcanistRevisionRef
     return $this->sources;
   }
 
+  public function getDisplayRefObjectName() {
+    return $this->getMonogram();
+  }
+
+  public function getDisplayRefTitle() {
+    return $this->getName();
+  }
+
 }

src/ref/symbol/ArcanistSymbolEngine.php

@@ -0,0 +1,78 @@
+<?php
+
+final class ArcanistSymbolEngine
+  extends Phobject {
+
+  private $workflow;
+  private $refs = array();
+
+  public function setWorkflow($workflow) {
+    $this->workflow = $workflow;
+    return $this;
+  }
+
+  public function getWorkflow() {
+    return $this->workflow;
+  }
+
+  public function loadRevisionForSymbol($symbol) {
+    $refs = $this->loadRevisionsForSymbols(array($symbol));
+    return head($refs)->getObject();
+  }
+
+  public function loadRevisionsForSymbols(array $symbols) {
+    return $this->loadRefsForSymbols(
+      new ArcanistRevisionSymbolRef(),
+      $symbols);
+  }
+
+  public function loadUserForSymbol($symbol) {
+    $refs = $this->loadUsersForSymbols(array($symbol));
+    return head($refs)->getObject();
+  }
+
+  public function loadUsersForSymbols(array $symbols) {
+    return $this->loadRefsForSymbols(
+      new ArcanistUserSymbolRef(),
+      $symbols);
+  }
+
+  public function loadCommitForSymbol($symbol) {
+    $refs = $this->loadCommitsForSymbols(array($symbol));
+    return head($refs)->getObject();
+  }
+
+  public function loadCommitsForSymbols(array $symbols) {
+    return $this->loadRefsForSymbols(
+      new ArcanistCommitSymbolRef(),
+      $symbols);
+  }
+
+  public function loadRefsForSymbols(
+    ArcanistSymbolRef $template,
+    array $symbols) {
+
+    $refs = array();
+    $load_refs = array();
+    foreach ($symbols as $symbol) {
+      $ref = id(clone $template)
+        ->setSymbol($symbol);
+
+      $ref_key = $ref->getSymbolEngineCacheKey();
+      if (!isset($this->refs[$ref_key])) {
+        $this->refs[$ref_key] = $ref;
+        $load_refs[] = $ref;
+      }
+
+      $refs[$symbol] = $ref;
+    }
+
+    $workflow = $this->getWorkflow();
+    if ($load_refs) {
+      $workflow->loadHardpoints($refs, ArcanistSymbolRef::HARDPOINT_OBJECT);
+    }
+
+    return $refs;
+  }
+
+}

src/ref/symbol/ArcanistSymbolRef.php

@@ -4,6 +4,7 @@ abstract class ArcanistSymbolRef
   extends ArcanistRef {
 
   private $symbol;
+  private $cacheKey;
 
   const HARDPOINT_OBJECT = 'ref.symbol.object';
 
@@ -24,6 +25,27 @@ abstract class ArcanistSymbolRef
     return $this->symbol;
   }
 
+  final public function getSymbolEngineCacheKey() {
+    if ($this->cacheKey === null) {
+      $parts = array();
+      $parts[] = sprintf('class(%s)', get_class($this));
+
+      foreach ($this->newCacheKeyParts() as $part) {
+        $parts[] = $part;
+      }
+
+      $parts[] = $this->getSymbol();
+
+      $this->cacheKey = implode('.', $parts);
+    }
+
+    return $this->cacheKey;
+  }
+
+  protected function newCacheKeyParts() {
+    return array();
+  }
+
   final public function attachObject(ArcanistRef $object) {
     return $this->attachHardpoint(self::HARDPOINT_OBJECT, $object);
   }
@@ -36,6 +58,4 @@ abstract class ArcanistSymbolRef
     return $symbol;
   }
 
-
-
 }

src/ref/user/ArcanistUserRef.php

@@ -34,8 +34,6 @@ final class ArcanistUserRef
   }
 
   public function getRealName() {
-    var_dump($this->parameters);
-
     return idxv($this->parameters, array('fields', 'realName'));
   }
 

src/ref/user/ArcanistUserSymbolRef.php

@@ -14,6 +14,12 @@ final class ArcanistUserSymbolRef
     return pht('User Symbol "%s"', $this->getSymbol());
   }
 
+  protected function newCacheKeyParts() {
+    return array(
+      sprintf('type(%s)', $this->type),
+    );
+  }
+
   public function getSymbolType() {
     return $this->type;
   }

src/workflow/ArcanistWorkflow.php

@@ -76,7 +76,9 @@ abstract class ArcanistWorkflow extends Phobject {
   private $configurationEngine;
   private $configurationSourceList;
 
+  private $viewer;
   private $hardpointEngine;
+  private $symbolEngine;
   private $promptMap;
 
   final public function setToolset(ArcanistToolset $toolset) {
@@ -2298,7 +2300,7 @@ abstract class ArcanistWorkflow extends Phobject {
       ->setExecutableFuture($future);
   }
 
-  final protected function loadHardpoints(
+  final public function loadHardpoints(
     $objects,
     $requests) {
 
@@ -2401,4 +2403,32 @@ abstract class ArcanistWorkflow extends Phobject {
     return clone $prompt;
   }
 
+  final protected function getSymbolEngine() {
+    if ($this->symbolEngine === null) {
+      $this->symbolEngine = $this->newSymbolEngine();
+    }
+    return $this->symbolEngine;
+  }
+
+  private function newSymbolEngine() {
+    return id(new ArcanistSymbolEngine())
+      ->setWorkflow($this);
+  }
+
+  final protected function getViewer() {
+    if (!$this->viewer) {
+      $viewer = $this->getSymbolEngine()
+        ->loadUserForSymbol('viewer()');
+
+      // TODO: Deal with anonymous stuff.
+      if (!$viewer) {
+        throw new Exception(pht('No viewer!'));
+      }
+
+      $this->viewer = $viewer;
+    }
+
+    return $this->viewer;
+  }
+
 }