paradedb · ankitml · Dec 19, 2025 · Dec 19, 2025 · Dec 19, 2025 · Dec 22, 2025
diff --git a/src/addBenchmarkEntry.ts b/src/addBenchmarkEntry.ts
@@ -2,6 +2,7 @@ import { Benchmark } from './extract';
 import * as core from '@actions/core';
 import { BenchmarkSuites } from './write';
 import { normalizeBenchmark } from './normalizeBenchmark';
+import { GitGraphAnalyzer } from './gitGraph';
 
 export function addBenchmarkEntry(
     benchName: string,
@@ -11,19 +12,25 @@ export function addBenchmarkEntry(
 ): { prevBench: Benchmark | null; normalizedCurrentBench: Benchmark } {
     let prevBench: Benchmark | null = null;
     let normalizedCurrentBench: Benchmark = benchEntry;
+    const gitAnalyzer = new GitGraphAnalyzer();
 
     // Add benchmark result
     if (entries[benchName] === undefined) {
         entries[benchName] = [benchEntry];
         core.debug(`No suite was found for benchmark '${benchName}' in existing data. Created`);
     } else {
         const suites = entries[benchName];
-        // Get the last suite which has different commit ID for alert comment
-        for (const e of [...suites].reverse()) {
-            if (e.commit.id !== benchEntry.commit.id) {
-                prevBench = e;
-                break;
-            }
+
+        // Use git-graph aware logic to find previous benchmark
+        const currentBranch = gitAnalyzer.getCurrentBranch();
+        core.debug(`Finding previous benchmark for branch: ${currentBranch}`);
+
+        prevBench = gitAnalyzer.findPreviousBenchmark(suites, benchEntry.commit.id, currentBranch);
+
+        if (prevBench) {
+            core.debug(`Found previous benchmark: ${prevBench.commit.id}`);
+        } else {
+            core.debug('No previous benchmark found');
         }
 
         normalizedCurrentBench = normalizeBenchmark(prevBench, benchEntry);

diff --git a/src/default_index_html.ts b/src/default_index_html.ts
@@ -127,6 +127,16 @@ export const DEFAULT_INDEX_HTML = String.raw`<!DOCTYPE html>
         };
 
         function init() {
+          function sortEntriesByGitOrder(entries) {
+            // Sort benchmarks by commit timestamp instead of execution time
+            // This provides better git graph ordering for visualization
+            return [...entries].sort((a, b) => {
+              const timestampA = new Date(a.commit.timestamp).getTime();
+              const timestampB = new Date(b.commit.timestamp).getTime();
+              return timestampA - timestampB;
+            });
+          }
+
           function collectBenchesPerTestCase(entries) {
             const map = new Map();
             for (const entry of entries) {
@@ -141,6 +151,14 @@ export const DEFAULT_INDEX_HTML = String.raw`<!DOCTYPE html>
                 }
               }
             }
+            // Sort each benchmark's data points by commit timestamp to ensure consistent ordering
+            for (const [benchName, arr] of map.entries()) {
+              arr.sort((a, b) => {
+                const timestampA = new Date(a.commit.timestamp).getTime();
+                const timestampB = new Date(b.commit.timestamp).getTime();
+                return timestampA - timestampB;
+              });
+            }
             return map;
           }
 
@@ -162,10 +180,14 @@ export const DEFAULT_INDEX_HTML = String.raw`<!DOCTYPE html>
           };
 
           // Prepare data points for charts
-          return Object.keys(data.entries).map(name => ({
-            name,
-            dataSet: collectBenchesPerTestCase(data.entries[name]),
-          }));
+          return Object.keys(data.entries).map(name => {
+            const entries = data.entries[name];
+            const sortedEntries = sortEntriesByGitOrder(entries);
+            return {
+              name,
+              dataSet: collectBenchesPerTestCase(sortedEntries),
+            };
+          });
         }
 
         function renderAllChars(dataSets) {

diff --git a/src/gitGraph.ts b/src/gitGraph.ts
@@ -0,0 +1,198 @@
+import * as github from '@actions/github';
+import { execSync } from 'child_process';
+import * as core from '@actions/core';
+import { Benchmark } from './extract';
+
+export class GitGraphAnalyzer {
+    private readonly gitCliAvailable: boolean;
+
+    constructor() {
+        // Check if we're in GitHub Actions environment (git CLI available)
+        this.gitCliAvailable = process.env.GITHUB_ACTIONS === 'true' && Boolean(process.env.GITHUB_WORKSPACE);
+    }
+
+    /**
+     * Get current branch from GitHub context
+     */
+    getCurrentBranch(): string {
+        const context = github.context;
+
+        // For pull requests, get the head branch
+        if (context.payload.pull_request) {
+            return context.payload.pull_request.head.ref;
+        }
+
+        // For pushes, get the branch from ref
+        if (context.ref) {
+            // Remove 'refs/heads/' prefix if present
+            return context.ref.replace('refs/heads/', '');
+        }
+
+        // Fallback to 'main' if we can't determine branch
+        return 'main';
+    }
+
+    /**
+     * Get git ancestry using topological order (only works in GitHub Actions environment)
+     */
+    getBranchAncestry(branch: string): string[] {
+        if (!this.gitCliAvailable) {
+            core.warning('Git CLI not available, cannot determine ancestry');
+            return [];
+        }
+
+        try {
+            const output = execSync(`git log --oneline --topo-order ${branch}`, {
+                encoding: 'utf8',
+                cwd: process.env.GITHUB_WORKSPACE ?? process.cwd(),
+            });
+
+            return output
+                .split('\n')
+                .filter((line) => line.trim())
+                .map((line) => line.split(' ')[0]); // Extract SHA from "sha message"
+        } catch (error) {
+            core.warning(`Failed to get ancestry for branch ${branch}: ${error}`);
+            return [];
+        }
+    }
+
+    /**
+     * Find previous benchmark commit based on git graph structure
+     */
+    findPreviousBenchmark(suites: Benchmark[], currentSha: string, branch: string): Benchmark | null {
+        const ancestry = this.getBranchAncestry(branch);
+
+        if (ancestry.length === 0) {
+            core.warning(`No ancestry found for branch ${branch}, falling back to execution time ordering`);
+            return this.findPreviousByExecutionTime(suites, currentSha);
+        }
+
+        // Find position of current commit in ancestry
+        const currentIndex = ancestry.indexOf(currentSha);
+        if (currentIndex === -1) {
+            core.warning(`Current commit ${currentSha} not found in ancestry, falling back to execution time ordering`);
+            return this.findPreviousByExecutionTime(suites, currentSha);
+        }
+
+        // Look for next commit in ancestry that exists in benchmarks
+        for (let i = currentIndex + 1; i < ancestry.length; i++) {
+            const previousSha = ancestry[i];
+            const previousBenchmark = suites.find((suite) => suite.commit.id === previousSha);
+
+            if (previousBenchmark) {
+                core.debug(`Found previous benchmark: ${previousSha} based on git ancestry`);
+                return previousBenchmark;
+            }
+        }
+
+        // Fallback: no previous commit found in ancestry
+        core.debug('No previous benchmark found in git ancestry');
+        return null;
+    }
+
+    /**
+     * Sort benchmark data by commit timestamp (for GitHub Pages visualization)
+     * This doesn't need git CLI - just uses the commit timestamps already stored
+     */
+    sortByGitOrder(suites: Benchmark[]): Benchmark[] {
+        if (suites.length === 0) return suites;
+
+        // For GitHub Pages, we don't have git CLI, so sort by commit timestamp
+        // This gives a reasonable approximation of git order
+        const sortedSuites = [...suites].sort((a, b) => {
+            const timestampA = new Date(a.commit.timestamp ?? '1970-01-01T00:00:00Z').getTime();
+            const timestampB = new Date(b.commit.timestamp ?? '1970-01-01T00:00:00Z').getTime();
+            return timestampA - timestampB;
+        });
+
+        core.debug('Sorted benchmarks by commit timestamp (GitHub Pages mode)');
+        return sortedSuites;
+    }
+
+    /**
+     * Advanced sorting using git CLI (only for GitHub Actions)
+     */
+    sortByGitOrderWithCLI(suites: Benchmark[]): Benchmark[] {
+        if (!this.gitCliAvailable) {
+            return this.sortByGitOrder(suites);
+        }
+
+        if (suites.length === 0) return suites;
+
+        // Create a map of SHA to benchmark for quick lookup
+        const benchmarkMap = new Map<string, Benchmark>();
+        for (const suite of suites) {
+            benchmarkMap.set(suite.commit.id, suite);
+        }
+
+        // Get ancestry from all commits (use the branch of the first commit)
+        const firstSuite = suites[0];
+        const branch = this.detectBranchForCommit(firstSuite.commit.id);
+        const ancestry = this.getBranchAncestry(branch);
+
+        if (ancestry.length === 0) {
+            core.warning('Could not determine git ancestry, falling back to timestamp sort');
+            return this.sortByGitOrder(suites);
+        }
+
+        // Sort benchmarks according to git ancestry
+        const sortedSuites: Benchmark[] = [];
+        for (const sha of ancestry) {
+            const benchmark = benchmarkMap.get(sha);
+            if (benchmark) {
+                sortedSuites.push(benchmark);
+            }
+        }
+
+        // Add any benchmarks not found in ancestry (shouldn't happen, but be safe)
+        for (const suite of suites) {
+            if (!sortedSuites.includes(suite)) {
+                sortedSuites.push(suite);
+            }
+        }
+
+        core.debug(`Sorted ${sortedSuites.length} benchmarks using git CLI ancestry`);
+        return sortedSuites;
+    }
+
+    /**
+     * Fallback method: find previous by execution time (original logic)
+     */
+    private findPreviousByExecutionTime(suites: Benchmark[], currentSha: string): Benchmark | null {
+        for (const suite of [...suites].reverse()) {
+            if (suite.commit.id !== currentSha) {
+                return suite;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Attempt to detect which branch a commit belongs to
+     */
+    private detectBranchForCommit(sha: string): string {
+        if (!this.gitCliAvailable) {
+            return 'main'; // Default for GitHub Pages
+        }
+
+        try {
+            // Try to find if commit is on current branch first
+            const currentBranch = this.getCurrentBranch();
+            const output = execSync(`git branch --contains ${sha}`, {
+                encoding: 'utf8',
+                cwd: process.env.GITHUB_WORKSPACE ?? process.cwd(),
+            });
+
+            if (output.includes(currentBranch)) {
+                return currentBranch;
+            }
+
+            // Default to main if we can't determine
+            return 'main';
+        } catch (error) {
+            core.warning(`Could not detect branch for commit ${sha}, defaulting to 'main'`);
+            return 'main';
+        }
+    }
+}