Aaron Schulz has uploaded a new change for review.
https://gerrit.wikimedia.org/r/305627
Change subject: Avoid INSERT..SELECT in doArticleDeleteReal()
......................................................................
Avoid INSERT..SELECT in doArticleDeleteReal()
That construct has poor locking characteristics in terms of
auto-inc columns as well as not allowing such inserts concurrently
for statement-based replication. Also, the INSERT..SELECT did not
have an ORDER BY, which could lead to ar_id drift with statement
based replication.
Change-Id: I9396869e474bc082fa6161b60afa3a5247df773b
---
M includes/page/WikiPage.php
1 file changed, 50 insertions(+), 46 deletions(-)
git pull ssh://gerrit.wikimedia.org:29418/mediawiki/core
refs/changes/27/305627/1
diff --git a/includes/page/WikiPage.php b/includes/page/WikiPage.php
index 0344756..065c4b4 100644
--- a/includes/page/WikiPage.php
+++ b/includes/page/WikiPage.php
@@ -2875,6 +2875,10 @@
return $status;
}
+ // Given the lock above, we can be confident in the title and
page ID values
+ $namespace = $this->getTitle()->getNamespace();
+ $dbKey = $this->getTitle()->getDBkey();
+
// At this point we are now comitted to returning an OK
// status unless some DB query error or other exception comes
up.
// This way callers don't have to call rollback() if $status is
bad
@@ -2895,54 +2899,54 @@
$bitfield = 'rev_deleted';
}
- /**
- * For now, shunt the revision data into the archive table.
- * Text is *not* removed from the text table; bulk storage
- * is left intact to avoid breaking block-compression or
- * immutable storage schemes.
- *
- * For backwards compatibility, note that some older archive
- * table entries will have ar_text and ar_flags fields still.
- *
- * In the future, we may keep revisions and mark them with
- * the rev_deleted field, which is reserved for this purpose.
- */
+ // For now, shunt the revision data into the archive table.
+ // Text is *not* removed from the text table; bulk storage
+ // is left intact to avoid breaking block-compression or
+ // immutable storage schemes.
+ //
+ // For backwards compatibility, note that some older archive
+ // table entries will have ar_text and ar_flags fields still.
+ //
+ // In the future, we may keep revisions and mark them with
+ // the rev_deleted field, which is reserved for this purpose.
- $row = [
- 'ar_namespace' => 'page_namespace',
- 'ar_title' => 'page_title',
- 'ar_comment' => 'rev_comment',
- 'ar_user' => 'rev_user',
- 'ar_user_text' => 'rev_user_text',
- 'ar_timestamp' => 'rev_timestamp',
- 'ar_minor_edit' => 'rev_minor_edit',
- 'ar_rev_id' => 'rev_id',
- 'ar_parent_id' => 'rev_parent_id',
- 'ar_text_id' => 'rev_text_id',
- 'ar_text' => '\'\'', // Be explicit to appease
- 'ar_flags' => '\'\'', // MySQL's "strict mode"...
- 'ar_len' => 'rev_len',
- 'ar_page_id' => 'page_id',
- 'ar_deleted' => $bitfield,
- 'ar_sha1' => 'rev_sha1',
- ];
-
- if ( $wgContentHandlerUseDB ) {
- $row['ar_content_model'] = 'rev_content_model';
- $row['ar_content_format'] = 'rev_content_format';
- }
-
- // Copy all the page revisions into the archive table
- $dbw->insertSelect(
- 'archive',
- [ 'page', 'revision' ],
- $row,
- [
- 'page_id' => $id,
- 'page_id = rev_page'
- ],
- __METHOD__
+ // Get all of the page revisions
+ $res = $dbw->select(
+ 'revision',
+ Revision::selectFields(),
+ [ 'rev_page' => $id ],
+ __METHOD__,
+ 'FOR UPDATE'
);
+ // Build their equivalent archive rows
+ $rowsInsert = [];
+ foreach ( $res as $row ) {
+ $rowInsert = [
+ 'ar_namespace' => $namespace,
+ 'ar_title' => $dbKey,
+ 'ar_comment' => $row->rev_comment,
+ 'ar_user' => $row->rev_user,
+ 'ar_user_text' => $row->rev_user_text,
+ 'ar_timestamp' => $row->rev_timestamp,
+ 'ar_minor_edit' => $row->rev_minor_edit,
+ 'ar_rev_id' => $row->rev_id,
+ 'ar_parent_id' => $row->rev_parent_id,
+ 'ar_text_id' => $row->rev_text_id,
+ 'ar_text' => '\'\'', // Be explicit to
appease
+ 'ar_flags' => '\'\'', // MySQL's "strict
mode"...
+ 'ar_len' => $row->rev_len,
+ 'ar_page_id' => $id,
+ 'ar_deleted' => $bitfield,
+ 'ar_sha1' => $row->rev_sha1,
+ ];
+ if ( $wgContentHandlerUseDB ) {
+ $rowInsert['ar_content_model'] =
$row->rev_content_model;
+ $rowInsert['ar_content_format'] =
$row->rev_content_format;
+ }
+ $rowsInsert[] = $rowInsert;
+ }
+ // Copy them into the archive table
+ $dbw->insert( 'archive', $rowsInsert, __METHOD__ );
// Save this so we can pass it to the ArticleDeleteComplete
hook.
$archivedRevisionCount = $dbw->affectedRows();
--
To view, visit https://gerrit.wikimedia.org/r/305627
To unsubscribe, visit https://gerrit.wikimedia.org/r/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: I9396869e474bc082fa6161b60afa3a5247df773b
Gerrit-PatchSet: 1
Gerrit-Project: mediawiki/core
Gerrit-Branch: master
Gerrit-Owner: Aaron Schulz <[email protected]>
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