Improve performance of repository discovery under Mercurial

Summary: Prelminary, I want to test this a bit more when I'm better rested. Provide a "bulk" import mode for Mercurial so we can do initial discovery more quickly.

Test Plan: Imported the Mercurial repository in 2m45s, blocked on MySQL I/O rather than Mercurial I/O.

Reviewers: csilvers, btrahan

Reviewed By: csilvers

CC: aran

Differential Revision: https://secure.phabricator.com/D2457

src/__phutil_library_map__.php

@@ -698,6 +698,7 @@ phutil_register_library_map(array(
     'PhabricatorMailImplementationTestAdapter' => 'applications/metamta/adapter/test',
     'PhabricatorMailReplyHandler' => 'applications/metamta/replyhandler/base',
     'PhabricatorMarkupEngine' => 'applications/markup/engine',
+    'PhabricatorMercurialGraphStream' => 'applications/repository/daemon/pulllocal',
     'PhabricatorMetaMTAAttachment' => 'applications/metamta/storage/mail',
     'PhabricatorMetaMTAController' => 'applications/metamta/controller/base',
     'PhabricatorMetaMTADAO' => 'applications/metamta/storage/base',
@@ -1360,6 +1361,7 @@ phutil_register_library_map(array(
     'DiffusionRawDiffQuery' => 'DiffusionQuery',
     'DiffusionRenameHistoryQuery' => 'DiffusionQuery',
     'DiffusionRepositoryController' => 'DiffusionController',
+    'DiffusionSetupException' => 'AphrontUsageException',
     'DiffusionSvnBrowseQuery' => 'DiffusionBrowseQuery',
     'DiffusionSvnCommitParentsQuery' => 'DiffusionCommitParentsQuery',
     'DiffusionSvnCommitTagsQuery' => 'DiffusionCommitTagsQuery',

src/applications/diffusion/query/browse/mercurial/DiffusionMercurialBrowseQuery.php

@@ -78,6 +78,7 @@ final class DiffusionMercurialBrowseQuery extends DiffusionBrowseQuery {
       $result = new DiffusionRepositoryPath();
       $result->setPath($key);
       $result->setFileType($type);
+      $result->setFullPath(ltrim($match_against.'/', '/').$key);
 
       $results[$key] = $result;
     }

src/applications/repository/daemon/pulllocal/PhabricatorMercurialGraphStream.php

@@ -0,0 +1,171 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Streaming interface on top of "hg log" that gives us performant access to
+ * the Mercurial commit graph with one nonblocking invocation of "hg". See
+ * @{class:PhabricatorRepositoryPullLocalDaemon}.
+ */
+final class PhabricatorMercurialGraphStream {
+
+  private $repository;
+  private $iterator;
+
+  private $parents        = array();
+  private $dates          = array();
+  private $local          = array();
+  private $localParents   = array();
+
+  public function __construct(PhabricatorRepository $repository) {
+    $this->repository = $repository;
+
+    $future = $repository->getLocalCommandFuture(
+      "log --template '{rev}\1{node}\1{date}\1{parents}\2'");
+
+    $this->iterator = new LinesOfALargeExecFuture($future);
+    $this->iterator->setDelimiter("\2");
+    $this->iterator->rewind();
+  }
+
+  public function getParents($commit) {
+    if (!isset($this->parents[$commit])) {
+      $this->parseUntil('node', $commit);
+
+      $local = $this->localParents[$commit];
+
+      // The normal parsing pass gives us the local revision numbers of the
+      // parents, but since we've decided we care about this data, we need to
+      // convert them into full hashes. To do this, we parse to the deepest
+      // one and then just look them up.
+
+      $parents = array();
+      if ($local) {
+        $this->parseUntil('rev', min($local));
+        foreach ($local as $rev) {
+          $parents[] = $this->local[$rev];
+        }
+      }
+
+      $this->parents[$commit] = $parents;
+
+      // Throw away the local info for this commit, we no longer need it.
+      unset($this->localParents[$commit]);
+    }
+
+    return $this->parents[$commit];
+  }
+
+  public function getCommitDate($commit) {
+    if (!isset($this->dates[$commit])) {
+      $this->parseUntil('node', $commit);
+    }
+    return $this->dates[$commit];
+  }
+
+  /**
+   * Parse until we have consumed some object. There are two types of parses:
+   * parse until we find a commit hash ($until_type = "node"), or parse until we
+   * find a local commit number ($until_type = "rev"). We use the former when
+   * looking up commits, and the latter when resolving parents.
+   */
+  private function parseUntil($until_type, $until_name) {
+    if ($this->isParsed($until_type, $until_name)) {
+      return;
+    }
+
+    $hglog = $this->iterator;
+
+    while ($hglog->valid()) {
+      $line = $hglog->current();
+      $hglog->next();
+
+      $line = trim($line);
+      if (!strlen($line)) {
+        break;
+      }
+      list($rev, $node, $date, $parents) = explode("\1", $line);
+
+      $rev  = (int)$rev;
+      $date = (int)head(explode('.', $date));
+
+      $this->dates[$node]        = $date;
+      $this->local[$rev]         = $node;
+      $this->localParents[$node] = $this->parseParents($parents, $rev);
+
+      if ($this->isParsed($until_type, $until_name)) {
+        return;
+      }
+    }
+
+    throw new Exception(
+      "No such {$until_type} '{$until_name}' in repository!");
+  }
+
+
+  /**
+   * Parse a {parents} template, returning the local commit numbers.
+   */
+  private function parseParents($parents, $target_rev) {
+
+    // The hg '{parents}' token is empty if there is one "natural" parent
+    // (predecessor local commit ID). Othwerwise, it may have one or two
+    // parents. The string looks like this:
+    //
+    //  151:1f6c61a60586 154:1d5f799ebe1e
+
+    $parents = trim($parents);
+    if (strlen($parents)) {
+      $local = array();
+
+      $parents = explode(' ', $parents);
+      foreach ($parents as $key => $parent) {
+        $parent = (int)head(explode(':', $parent));
+        if ($parent == -1) {
+          // Initial commits will sometimes have "-1" as a parent.
+          continue;
+        }
+        $local[] = $parent;
+      }
+    } else if ($target_rev) {
+      // We have empty parents. If there's a predecessor, that's the local
+      // parent number.
+      $local = array($target_rev - 1);
+    } else {
+      // Initial commits will sometimes have no parents.
+      $local = array();
+    }
+
+    return $local;
+  }
+
+
+  /**
+   * Returns true if the object specified by $type ('rev' or 'node') and
+   * $name (rev or node name) has been consumed from the hg process.
+   */
+  private function isParsed($type, $name) {
+    switch ($type) {
+      case 'rev':
+        return isset($this->local[$name]);
+      case 'node':
+        return isset($this->dates[$name]);
+    }
+  }
+
+
+}

src/applications/repository/daemon/pulllocal/PhabricatorRepositoryPullLocalDaemon.php

@@ -665,15 +665,15 @@ final class PhabricatorRepositoryPullLocalDaemon
 
     $seen_parent = array();
 
-    // For all the new commits at the branch heads, walk backward until we find
-    // only commits we've aleady seen.
-    while (true) {
+    $stream = new PhabricatorMercurialGraphStream($repository);
+
+    // For all the new commits at the branch heads, walk backward until we
+    // find only commits we've aleady seen.
+    while ($discover) {
       $target = array_pop($discover);
-      list($stdout) = $repository->execxLocalCommand(
-        'parents --rev %s --template %s',
-        $target,
-        '{node}\n');
-      $parents = array_filter(explode("\n", trim($stdout)));
+
+      $parents = $stream->getParents($target);
+
       foreach ($parents as $parent) {
         if (isset($seen_parent[$parent])) {
           continue;
@@ -684,24 +684,11 @@ final class PhabricatorRepositoryPullLocalDaemon
           $insert[] = $parent;
         }
       }
-      if (empty($discover)) {
-        break;
-      }
     }
 
-    while (true) {
-      $target = array_pop($insert);
-      list($stdout) = $repository->execxLocalCommand(
-        'log --rev %s --template %s',
-        $target,
-        '{date|rfc822date}');
-      $epoch = strtotime($stdout);
-
+    foreach ($insert as $target) {
+      $epoch = $stream->getCommitDate($target);
       self::recordCommit($repository, $target, $epoch);
-
-      if (empty($insert)) {
-        break;
-      }
     }
   }
 

src/applications/repository/daemon/pulllocal/__init__.php

@@ -20,8 +20,10 @@ phutil_require_module('phabricator', 'storage/queryfx');
 
 phutil_require_module('phutil', 'error');
 phutil_require_module('phutil', 'filesystem');
+phutil_require_module('phutil', 'filesystem/linesofalarge/execfuture');
 phutil_require_module('phutil', 'parser/argument/parser');
 phutil_require_module('phutil', 'utils');
 
 
+phutil_require_source('PhabricatorMercurialGraphStream.php');
 phutil_require_source('PhabricatorRepositoryPullLocalDaemon.php');