Remove PhabricatorFile::buildFromFileDataOrHash()

Summary:
Ref T12464. This is a very old method which can return an existing file instead of creating a new one, if there's some existing file with the same content.

In the best case this is a bad idea. This being somewhat reasonable predates policies, temporary files, etc. Modern methods like `newFromFileData()` do this right: they share underlying data in storage, but not the actual `File` records.

Specifically, this is the case where we get into trouble:

  - I upload a private file with content "X".
  - You somehow generate a file with the same content by, say, viewing a raw diff in Differential.
  - If the diff had the same content, you get my file, but you don't have permission to see it or whatever so everything breaks and is terrible.

Just get rid of this.

Test Plan:
  - Generated an SSH key.
  - Viewed a raw diff in Differential.
  - (Did not test Phragment.)

Reviewers: chad

Reviewed By: chad

Subscribers: hach-que

Maniphest Tasks: T12464

Differential Revision: https://secure.phabricator.com/D17617

src/applications/auth/controller/PhabricatorAuthSSHKeyGenerateController.php

@@ -24,7 +24,7 @@ final class PhabricatorAuthSSHKeyGenerateController
       $keys = PhabricatorSSHKeyGenerator::generateKeypair();
       list($public_key, $private_key) = $keys;
 
-      $file = PhabricatorFile::buildFromFileDataOrHash(
+      $file = PhabricatorFile::newFromFileData(
         $private_key,
         array(
           'name' => $default_name.'.key',

src/applications/differential/controller/DifferentialRevisionViewController.php

@@ -889,7 +889,8 @@ final class DifferentialRevisionViewController extends DifferentialController {
     }
     $file_name .= 'diff';
 
-    $file = PhabricatorFile::buildFromFileDataOrHash(
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+      $file = PhabricatorFile::newFromFileData(
         $raw_diff,
         array(
           'name' => $file_name,
@@ -897,7 +898,6 @@ final class DifferentialRevisionViewController extends DifferentialController {
           'viewPolicy' => PhabricatorPolicies::POLICY_NOONE,
         ));
 
-    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
       $file->attachToObject($revision->getPHID());
     unset($unguarded);
 

src/applications/files/storage/PhabricatorFile.php

@@ -197,44 +197,6 @@ final class PhabricatorFile extends PhabricatorFileDAO
   }
 
 
-  /**
-   * Given a block of data, try to load an existing file with the same content
-   * if one exists. If it does not, build a new file.
-   *
-   * This method is generally used when we have some piece of semi-trusted data
-   * like a diff or a file from a repository that we want to show to the user.
-   * We can't just dump it out because it may be dangerous for any number of
-   * reasons; instead, we need to serve it through the File abstraction so it
-   * ends up on the CDN domain if one is configured and so on. However, if we
-   * simply wrote a new file every time we'd potentially end up with a lot
-   * of redundant data in file storage.
-   *
-   * To solve these problems, we use file storage as a cache and reuse the
-   * same file again if we've previously written it.
-   *
-   * NOTE: This method unguards writes.
-   *
-   * @param string  Raw file data.
-   * @param dict    Dictionary of file information.
-   */
-  public static function buildFromFileDataOrHash(
-    $data,
-    array $params = array()) {
-
-    $file = id(new PhabricatorFile())->loadOneWhere(
-      'name = %s AND contentHash = %s LIMIT 1',
-      idx($params, 'name'),
-      self::hashFileContent($data));
-
-    if (!$file) {
-      $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
-      $file = self::newFromFileData($data, $params);
-      unset($unguarded);
-    }
-
-    return $file;
-  }
-
   public static function newFileFromContentHash($hash, array $params) {
     // Check to see if a file with same contentHash exist
     $file = id(new PhabricatorFile())->loadOneWhere(

src/applications/phragment/conduit/PhragmentGetPatchConduitAPIMethod.php

@@ -174,12 +174,15 @@ final class PhragmentGetPatchConduitAPIMethod
       unset($patches[$key]['fileOld']);
       unset($patches[$key]['fileNew']);
 
-      $file = PhabricatorFile::buildFromFileDataOrHash(
+      $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+        $file = PhabricatorFile::newFromFileData(
           $data,
           array(
             'name' => 'patch.dmp',
             'ttl.relative' => phutil_units('24 hours in seconds'),
           ));
+      unset($unguarded);
+
       $patches[$key]['patchURI'] = $file->getDownloadURI();
     }
 

src/applications/phragment/controller/PhragmentPatchController.php

@@ -78,7 +78,8 @@ final class PhragmentPatchController extends PhragmentController {
       $return = $request->getStr('return');
     }
 
-    $result = PhabricatorFile::buildFromFileDataOrHash(
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+      $result = PhabricatorFile::newFromFileData(
         $patch,
         array(
           'name' => $name,
@@ -86,7 +87,6 @@ final class PhragmentPatchController extends PhragmentController {
           'ttl.relative' => phutil_units('24 hours in seconds'),
         ));
 
-    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
       $result->attachToObject($version_b->getFragmentPHID());
     unset($unguarded);
 

src/applications/phragment/controller/PhragmentZIPController.php

@@ -100,14 +100,15 @@ final class PhragmentZIPController extends PhragmentController {
     }
 
     $data = Filesystem::readFile((string)$temp);
-    $file = PhabricatorFile::buildFromFileDataOrHash(
+
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+      $file = PhabricatorFile::newFromFileData(
         $data,
         array(
           'name' => $zip_name,
           'ttl.relative' => phutil_units('24 hours in seconds'),
         ));
 
-    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
       $file->attachToObject($fragment->getPHID());
     unset($unguarded);