Commit 96fde137 authored by epriestley's avatar epriestley

Improve performance of "arc diff" updates for changes with large diff text

Summary:
See PHI1104. The older "differential.querydiffs" method includes the entire raw diff text for all the diffs associated with a revision in its response, but we: only care about the most recent diff; and don't care about the text at all.

For reasonably large changes with several updates, this can be significantly slow.

We can get this same information more efficiently from the modern "differential.diff.search", since D19386 (April 2018). The only trick is that we need a "revisionPHID", which we don't have on hand.

For now, just fetch the revision PHID. In the future, we can likely make adjustments so that we have the revision PHID already by the time we get here.

This may slow down the normal case very slightly (since we now do two calls instead of one), but it speeds up the bad cases dramatically.

Test Plan:
Ran `arc diff` to update a change in a local repository. `var_dump()`'d the old and new algorithm results, saw the same outcome.

Used `arc diff --trace` on an update to a change to verify that `differential.diff.search` is called but `differential.querydiffs` is not.

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D20221
parent 9581dd0f
......@@ -2164,8 +2164,8 @@ EOTEXT
// we always get this 100% right, we're just trying to do something
// reasonable.
$local = $this->loadActiveLocalCommitInfo();
$hashes = ipull($local, null, 'commit');
$hashes = $this->loadActiveDiffLocalCommitHashes();
$hashes = array_fuse($hashes);
$usable = array();
foreach ($commit_messages as $message) {
......@@ -2212,8 +2212,8 @@ EOTEXT
return null;
}
$local = $this->loadActiveLocalCommitInfo();
$hashes = ipull($local, null, 'commit');
$hashes = $this->loadActiveDiffLocalCommitHashes();
$hashes = array_fuse($hashes);
$usable = array();
foreach ($messages as $rev => $message) {
......@@ -2261,7 +2261,63 @@ EOTEXT
return implode('', $default);
}
private function loadActiveLocalCommitInfo() {
private function loadActiveDiffLocalCommitHashes() {
// The older "differential.querydiffs" method includes the full diff text,
// which can be very slow for large diffs. If we can, try to use
// "differential.diff.search" instead.
// We expect this to fail if the Phabricator version on the server is
// older than April 2018 (D19386), which introduced the "commits"
// attachment for "differential.revision.search".
// TODO: This can be optimized if we're able to learn the "revisionPHID"
// before we get here. See PHI1104.
try {
$revisions_raw = $this->getConduit()->callMethodSynchronous(
'differential.revision.search',
array(
'constraints' => array(
'ids' => array(
$this->revisionID,
),
),
));
$revisions = $revisions_raw['data'];
$revision = head($revisions);
if ($revision) {
$revision_phid = $revision['phid'];
$diffs_raw = $this->getConduit()->callMethodSynchronous(
'differential.diff.search',
array(
'constraints' => array(
'revisionPHIDs' => array(
$revision_phid,
),
),
'attachments' => array(
'commits' => true,
),
'limit' => 1,
));
$diffs = $diffs_raw['data'];
$diff = head($diffs);
if ($diff) {
$commits = idxv($diff, array('attachments', 'commits', 'commits'));
if ($commits !== null) {
$hashes = ipull($commits, 'identifier');
return array_values($hashes);
}
}
}
} catch (Exception $ex) {
// If any of this fails, fall back to the older method below.
}
$current_diff = $this->getConduit()->callMethodSynchronous(
'differential.querydiffs',
array(
......@@ -2270,7 +2326,10 @@ EOTEXT
$current_diff = head($current_diff);
$properties = idx($current_diff, 'properties', array());
return idx($properties, 'local:commits', array());
$local = idx($properties, 'local:commits', array());
$hashes = ipull($local, 'commit');
return array_values($hashes);
}
......
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