Move all path alias SQL queries to a single storage controller

+ $query = db_select('url_alias')

You mean

+ $query = $this->connection->select('url_alias')

As catch is listed in MAINTAINERS as the sole Path system maintainer I have no better idea than marking this ready and assigning it to him.

1. +++ b/core/lib/Drupal/Core/Path/Path.php
   @@ -246,4 +246,87 @@ public function lookupPathSource($path, $langcode) {
   +   * Checks if same alias already exists for a different path.
   

   The word "same" is redundant.

2. +++ b/core/lib/Drupal/Core/Path/Path.php
   @@ -246,4 +246,87 @@ public function lookupPathSource($path, $langcode) {
   +   * Loads list of alias for one page of alias admin listing.
   

   How about "Loads aliases for admin listing."

3. +++ b/core/lib/Drupal/Core/Path/Path.php
   @@ -246,4 +246,87 @@ public function lookupPathSource($path, $langcode) {
   +   * Check if path (prefix) already has any alias-es.
   +   *
   +   * @param $path_prefix
   +   *   Path prefix to test for.
   +   * @return
   +   *   TRUE if alias-es exists, FALSE otherwise.
   +   */
   +  public function pathHasAlias($path_prefix) {
   +    $query = $this->connection->select('url_alias', 'u');
   +    $query->addExpression(1);
   +    return (bool) $query
   +      ->condition('u.source', $this->connection->escapeLike($path_prefix) . '%', 'LIKE')
   +      ->range(0, 1)
   +      ->execute()
   +      ->fetchField();
   +  }
   

   This needs improving but I haven't come up with something yet. I don't feel the method has the right name.

Also I notice that Path does not have an interface so swapping out implementation will prove difficult until it does - can someone open a followup to create one?

How about that version ? It seems rather closer to what the code does..

Rerolled with an interdiff on #7: I had missed a method call.

The related interface issue appears to already exist as #2199381: Add \Drupal\Core\Path\PathInterface

@fgm
Please use the -up format for the interdiff, otherwise it is quite hard to read.

1. +++ b/core/lib/Drupal/Core/Path/Path.php
   @@ -246,4 +246,87 @@ public function lookupPathSource($path, $langcode) {
   +   * Checks if alias already exists for a different path.
   

   This can check for any path if $source is NULL, could do with a more generic summary, maybe just remove 'for a different path'?

   Also what's the use case for passing in $pid?

2. +++ b/core/lib/Drupal/Core/Path/Path.php
   @@ -246,4 +246,87 @@ public function lookupPathSource($path, $langcode) {
   +   * Check if any alias exists starting by $path_prefix.
   

   Should be 'starting with'. Also not sure about the use of $path_prefix here, we already use that for things like language prefixes for things that precede the actual alias. i.e. the $prefix option for UrlGenerator::generateFromPath. Not sure what, $pattern? $substring?

OK, how about this wording ?

Followup issue after #2199381: Add \Drupal\Core\Path\PathInterface if merged: #2224933: Path storage abstraction followup. No longer needed after next patch.

21: 2209145_21.patch queued for re-testing.

1. +++ b/core/lib/Drupal/Core/Path/Path.php
   @@ -186,4 +186,83 @@ public function lookupPathSource($path, $langcode) {
   +  public function adminListing($header, $keys = NULL) {
   

   I wonder whether some better describing name like :getAliasesForAdminListing could be used. Otherwise this could be nearly a render array.

2. +++ b/core/lib/Drupal/Core/Path/Path.php
   @@ -186,4 +186,83 @@ public function lookupPathSource($path, $langcode) {
   +*@return
   

   ups

Rerolled.

Seems like all points are addressed. https://drupal.org/documentation/git/interdiff thanks!

Rerolling after #2221065: Rename default 'cache' cache bin to 'default'.

Let's try this again.

Thanks!