From a123cd63ba2e5f4280ef6640c63e464aea10c504 Mon Sep 17 00:00:00 2001
From: roxblnfk <roxblnfk@ya.ru>
Date: Sat, 6 Jul 2024 21:51:31 +0400
Subject: [PATCH] feat(frontend): support sorting in profiler "Top functions"
 table

---
 .../Frontend/Module/Profiler/Mapper.php       | 15 +++-
 src/Module/Profiler/Struct/Tree.php           | 38 ++++++++++
 .../Unit/Module/Profiler/Struct/TreeTest.php  | 70 +++++++++++++++++++
 3 files changed, 121 insertions(+), 2 deletions(-)
 create mode 100644 tests/Unit/Module/Profiler/Struct/TreeTest.php

diff --git a/src/Module/Frontend/Module/Profiler/Mapper.php b/src/Module/Frontend/Module/Profiler/Mapper.php
index bc7331c2..68f49b54 100644
--- a/src/Module/Frontend/Module/Profiler/Mapper.php
+++ b/src/Module/Frontend/Module/Profiler/Mapper.php
@@ -8,6 +8,7 @@
 use Buggregator\Trap\Module\Frontend\Module\Profiler\Message\CallGraph;
 use Buggregator\Trap\Module\Frontend\Module\Profiler\Message\FlameChart;
 use Buggregator\Trap\Module\Frontend\Module\Profiler\Message\TopFunctions;
+use Buggregator\Trap\Module\Profiler\Struct\Branch;
 use Buggregator\Trap\Proto\Frame\Profiler\Payload as ProfilerPayload;
 
 /**
@@ -38,8 +39,18 @@ public function topFunctions(Event $event, string $metric): TopFunctions
 
         // Get top
         $top = [];
-        foreach ($profile->calls->all as $branch) {
-            // todo: limit with 100 and sort
+        $topBranches = $profile->calls->top(
+            100,
+            match ($metric) {
+                'ct' => static fn(Branch $a, Branch $b): int => $b->item->cost->ct <=> $a->item->cost->ct,
+                'cpu' => static fn(Branch $a, Branch $b): int => $b->item->cost->cpu <=> $a->item->cost->cpu,
+                'mu' => static fn(Branch $a, Branch $b): int => $b->item->cost->mu <=> $a->item->cost->mu,
+                'pmu' => static fn(Branch $a, Branch $b): int => $b->item->cost->pmu <=> $a->item->cost->pmu,
+                default => static fn(Branch $a, Branch $b): int => $b->item->cost->wt <=> $a->item->cost->wt,
+            }
+        );
+
+        foreach ($topBranches as $branch) {
             $top[] = TopFunctions\Func::fromEdge($branch->item);
         }
 
diff --git a/src/Module/Profiler/Struct/Tree.php b/src/Module/Profiler/Struct/Tree.php
index 8c5e0230..3f2976d2 100644
--- a/src/Module/Profiler/Struct/Tree.php
+++ b/src/Module/Profiler/Struct/Tree.php
@@ -46,6 +46,44 @@ public static function fromEdgesList(array $edges, callable $getCurrent, callabl
         return $tree;
     }
 
+    /**
+     * Get the top N branches by a custom sorting.
+     *
+     * @param int<1, max> $limit
+     * @param callable(Branch<TItem>, Branch<TItem>): int $sorter
+     *
+     * @return list<Branch>
+     */
+    public function top(int $limit, callable $sorter): array
+    {
+        // Get N branches and sort it
+        $all = \array_values($this->all);
+        $result = \array_slice($all, 0, $limit);
+        \usort($result, $sorter);
+
+        // Compare next item with the last of the top
+        // and resort the top one by one
+        $end = \array_key_last($result);
+        $next = $limit - 1;
+
+        while (++$next < \count($all)) {
+            if ($sorter($all[$next], $result[$end]) > 0) {
+                continue;
+            }
+
+            // Add the next item to the top
+            $result[$end] = $all[$next];
+
+            // Sort
+            $current = $end;
+            while (--$current >= 0 && $sorter($result[$current], $result[$current + 1]) > 0) {
+                [$result[$current], $result[$current + 1]] = [$result[$current + 1], $result[$current]];
+            }
+        }
+
+        return $result;
+    }
+
     /**
      * @param non-empty-string $id
      * @param non-empty-string|null $parentId
diff --git a/tests/Unit/Module/Profiler/Struct/TreeTest.php b/tests/Unit/Module/Profiler/Struct/TreeTest.php
new file mode 100644
index 00000000..592961a6
--- /dev/null
+++ b/tests/Unit/Module/Profiler/Struct/TreeTest.php
@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Buggregator\Trap\Tests\Unit\Module\Profiler\Struct;
+
+use Buggregator\Trap\Module\Profiler\Struct\Branch;
+use Buggregator\Trap\Module\Profiler\Struct\Cost;
+use Buggregator\Trap\Module\Profiler\Struct\Edge;
+use Buggregator\Trap\Module\Profiler\Struct\Tree;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+
+class TreeTest extends TestCase
+{
+    public static function topNumbers(): iterable
+    {
+        yield [1];
+        yield [5];
+        yield [10];
+        yield [100];
+        yield [1000];
+    }
+
+    #[DataProvider('topNumbers')]
+    public function testTop(int $top): void
+    {
+        $edges = $this->generateEdges();
+        $tree = Tree::fromEdgesList(
+            $edges,
+            static fn(Edge $edge) => $edge->callee,
+            static fn(Edge $edge) => $edge->caller,
+        );
+
+        $result = $tree->top($top, static fn(Branch $a,Branch $b) => $b->item->cost->wt <=> $a->item->cost->wt);
+
+        self::assertCount(\min($top, \count($edges)), $result);
+
+        $topUnoptimized = \array_map(static fn (Edge $e) => $e->cost->wt, $edges);
+        \rsort($topUnoptimized);
+        $topUnoptimized = \array_slice($topUnoptimized, 0, $top);
+        $topVals = \array_map(static fn (Branch $b) => $b->item->cost->wt, $result);
+        self::assertSame($topUnoptimized, $topVals);
+    }
+
+    /**
+     * @return array<Edge>
+     */
+    private function generateEdges(int $multiplier = 20): array
+    {
+        $result = [];
+
+        for ($i = 0; $i < $multiplier; $i++) {
+            for ($j = 0; $j <= $i; $j++) {
+                $result[] = new Edge(
+                    $i === 0 ? null : 'item-' . ($i - 1) . "-$j", "item-$i-$j",
+                    new Cost(
+                        ct: (int) $i**$i,
+                        wt: ($multiplier - $i) * 1000 + $j,
+                        cpu: ($multiplier - $i) * 10,
+                        mu: (int) $i * 1000,
+                        pmu: (int) $i * 1000,
+                    ),
+                );
+            }
+        }
+
+        return $result;
+    }
+}