Add benchmarker app

benchmarker/.gitignore

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+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.build/
+.buildlog/
+.history
+.svn/
+.swiftpm/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins-dependencies
+.pub-cache/
+.pub/
+/build/
+/coverage/
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release

benchmarker/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "058e0af2c2b57e369d905a03ac9748b0ebf543c6"
+  channel: "stable"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+      base_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+    - platform: android
+      create_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+      base_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+    - platform: ios
+      create_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+      base_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+    - platform: linux
+      create_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+      base_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+    - platform: macos
+      create_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+      base_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+    - platform: windows
+      create_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+      base_revision: 058e0af2c2b57e369d905a03ac9748b0ebf543c6
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'

benchmarker/README.md

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+# http_cache_stream benchmarker
+
+A standalone Flutter app that benchmarks HTTP responses served by
+`http_cache_stream`'s local cache server, and compares them against requests
+that bypass the package entirely.
+
+It depends on the package by path (`http_cache_stream: {path: ../}`), so it
+always benchmarks the working copy of the repository.
+
+Supported platforms: Android, iOS, Linux, macOS, Windows. Web is unsupported —
+the benchmark relies on `dart:io` and `dart:isolate`.
+
+```bash
+cd benchmarker
+flutter run -d <device>
+```
+
+## What it measures
+
+Requests are issued by a pool of **long-lived worker isolates**. Each isolate
+builds exactly one `http.Client` when it starts and reuses it for every request,
+so connection pools stay warm both within and between runs. The pool is only
+respawned when the concurrency or the client implementation changes.
+
+### Inputs
+
+| Input | Meaning |
+| --- | --- |
+| Source URL | The remote URL under test. |
+| Concurrency | Number of worker isolates. |
+| Total requests | Requests issued in total, divided evenly between the workers (the remainder goes to the lowest-numbered workers). |
+| Request range | Which bytes each request asks for: a mode plus a slider bounding the region. |
+
+### Request range
+
+| Mode | Behavior |
+| --- | --- |
+| **Full response** | No `Range` header; every request downloads the whole source. |
+| **Fixed range** | Every request asks for the same slider selection. |
+| **Sequential windows** | The selection is divided between the requests: request *n* asks for the *n*-th window, each the same size, one starting where the last ended. |
+
+Sequential windows are sized by the total request count — `window = ⌈range ÷
+requests⌉` — so the run walks the selected region exactly once. The final window
+slides back to end on the last byte, which keeps every request the same size at
+the cost of a small overlap when the division isn't even. Windows are assigned
+by each request's global sequence number, so workers cover consecutive blocks of
+the region concurrently.
+
+Both partial modes need the source's size to express a selection in bytes, so
+they stay disabled until **Fetch length** probes the URL — a `HEAD`, falling
+back to a one-byte range request, which also reveals whether the server honors
+`Range` at all. The probed length is dropped as soon as the URL is edited, so a
+stale size can never be applied to a different source.
+
+Each request then carries `Range: bytes=<start>-<end>`, and the response's byte
+count is verified against its `Content-Length` exactly as a full response is. A
+run whose range requests come back as anything other than `206 Partial Content`
+logs a warning once — the server is likely ignoring the range.
+
+### Run types
+
+| Type | Behavior |
+| --- | --- |
+| **Pre-cached** | The file is fully downloaded first, then every benchmarked request is served from the completed cache file. |
+| **Non-cached** | The cache files are deleted first, so the requests race the cache download. |
+| **Direct** | `http_cache_stream` is bypassed; workers request the source URL. |
+
+### HTTP client
+
+The client each worker uses is chosen from a registry of
+[`HttpClientBuilder`](lib/src/benchmark/http_client_builder.dart)s — top-level
+functions sent to the isolate at spawn time. Add an entry to
+`kHttpClientOptions` to benchmark another implementation (for example
+`cupertino_http` or `cronet_http`); nothing else needs to change.
+
+### Output
+
+Per run, aggregated from the results streamed back by the workers and refreshed
+roughly four times a second:
+
+- Average, p50/p90/p99, min and max for **time to response headers**, **time to
+  first byte**, and **time to completion**.
+- **Requests per second**, **bytes per second**, total bytes, average response
+  size, and elapsed wall-clock time.
+- Outcome breakdown: verified, unverified (no `Content-Length`), byte
+  mismatches, HTTP errors, and failures.
+
+Every response's received byte count is checked against its `Content-Length`; a
+mismatch is reported as a problem rather than a success.
+
+The copy button at the top right of the statistics panel puts the whole run on
+the clipboard — source URL, target URL, cache type, request range, client and
+concurrency alongside the numbers — as either an aligned plain-text summary or
+JSON for feeding into other tooling.
+
+For cache-server runs, the page also shows live download progress
+(`x / y bytes`, percentage) taken from `HttpCacheStream.cacheStateStream`, and
+errors emitted by that stream are written to the log panel along with the run's
+status lines.
+
+## Layout
+
+```
+lib/
+  main.dart                              app entry; initializes HttpCacheManager
+  src/benchmark/
+    benchmark_config.dart                inputs, run types, request distribution
+    benchmark_controller.dart            run orchestration and aggregation
+    benchmark_report.dart                clipboard reports (text and JSON)
+    benchmark_stats.dart                 timing/percentile accumulation
+    benchmark_worker.dart                worker isolate entry point
+    http_client_builder.dart             selectable http client implementations
+    source_probe.dart                    content-length / range-support probe
+    worker_pool.dart                     long-lived isolate pool
+    worker_protocol.dart                 messages exchanged with the workers
+  src/ui/
+    benchmark_form.dart                  input state, owned by the page
+    benchmark_page.dart                  page layout
+    widgets/                             config, progress, stats and log panels
+```
+
+## Tests
+
+```bash
+cd benchmarker
+flutter test
+```
+
+The suite covers request distribution and statistics, drives real worker
+isolates against a local origin server, and runs all three benchmark types
+end-to-end through a real `HttpCacheManager`.
+
+> When testing against a **loopback** origin, address it as `localhost` rather
+> than `127.0.0.1`: `http_cache_stream` rejects source URLs whose host matches
+> the cache server's own host.

benchmarker/analysis_options.yaml

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+# This file configures the analyzer, which statically analyzes Dart code to
+# check for errors, warnings, and lints.
+#
+# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
+# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
+# invoked from the command line by running `flutter analyze`.
+
+# The following line activates a set of recommended lints for Flutter apps,
+# packages, and plugins designed to encourage good coding practices.
+include: package:flutter_lints/flutter.yaml
+
+linter:
+  # The lint rules applied to this project can be customized in the
+  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
+  # included above or to enable additional rules. A list of all available lints
+  # and their documentation is published at https://dart.dev/lints.
+  #
+  # Instead of disabling a lint rule for the entire project in the
+  # section below, it can also be suppressed for a single line of code
+  # or a specific dart file by using the `// ignore: name_of_lint` and
+  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
+  # producing the lint.
+  rules:
+    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
+    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
+
+# Additional information about this file can be found at
+# https://dart.dev/guides/language/analysis-options

benchmarker/android/.gitignore

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+gradle-wrapper.jar
+/.gradle
+/captures/
+/gradlew
+/gradlew.bat
+/local.properties
+GeneratedPluginRegistrant.java
+.cxx/
+
+# Remember to never publicly share your keystore.
+# See https://flutter.dev/to/reference-keystore
+key.properties
+**/*.keystore
+**/*.jks

benchmarker/android/app/build.gradle.kts

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+plugins {
+    id("com.android.application")
+    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
+    id("dev.flutter.flutter-gradle-plugin")
+}
+
+android {
+    namespace = "com.httpcachestream.benchmarker"
+    compileSdk = flutter.compileSdkVersion
+    ndkVersion = flutter.ndkVersion
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    defaultConfig {
+        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
+        applicationId = "com.httpcachestream.benchmarker"
+        // You can update the following values to match your application needs.
+        // For more information, see: https://flutter.dev/to/review-gradle-config.
+        minSdk = flutter.minSdkVersion
+        targetSdk = flutter.targetSdkVersion
+        versionCode = flutter.versionCode
+        versionName = flutter.versionName
+    }
+
+    buildTypes {
+        release {
+            // TODO: Add your own signing config for the release build.
+            // Signing with the debug keys for now, so `flutter run --release` works.
+            signingConfig = signingConfigs.getByName("debug")
+        }
+    }
+}
+
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
+    }
+}
+
+flutter {
+    source = "../.."
+}

benchmarker/android/app/src/debug/AndroidManifest.xml

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+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- The INTERNET permission is required for development. Specifically,
+         the Flutter tool needs it to communicate with the running application
+         to allow setting breakpoints, to provide hot reload, etc.
+    -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+</manifest>

benchmarker/android/app/src/main/AndroidManifest.xml

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+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <application
+        android:label="benchmarker"
+        android:name="${applicationName}"
+        android:icon="@mipmap/ic_launcher"
+        android:networkSecurityConfig="@xml/network_security_config">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:launchMode="singleTop"
+            android:taskAffinity=""
+            android:theme="@style/LaunchTheme"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+            android:hardwareAccelerated="true"
+            android:windowSoftInputMode="adjustResize">
+            <!-- Specifies an Android theme to apply to this Activity as soon as
+                 the Android process has started. This theme is visible to the user
+                 while the Flutter UI initializes. After that, this theme continues
+                 to determine the Window background behind the Flutter UI. -->
+            <meta-data
+              android:name="io.flutter.embedding.android.NormalTheme"
+              android:resource="@style/NormalTheme"
+              />
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+            </intent-filter>
+        </activity>
+        <!-- Don't delete the meta-data below.
+             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
+        <meta-data
+            android:name="flutterEmbedding"
+            android:value="2" />
+    </application>
+    <!-- Required to query activities that can process text, see:
+         https://developer.android.com/training/package-visibility and
+         https://developer.android.com/reference/android/content/Intent#ACTION_PROCESS_TEXT.
+
+         In particular, this is used by the Flutter engine in io.flutter.plugin.text.ProcessTextPlugin. -->
+    <queries>
+        <intent>
+            <action android:name="android.intent.action.PROCESS_TEXT"/>
+            <data android:mimeType="text/plain"/>
+        </intent>
+    </queries>
+</manifest>

benchmarker/android/app/src/main/kotlin/com/httpcachestream/benchmarker/MainActivity.kt

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+package com.httpcachestream.benchmarker
+
+import io.flutter.embedding.android.FlutterActivity
+
+class MainActivity : FlutterActivity()

benchmarker/android/app/src/main/res/drawable-v21/launch_background.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="?android:colorBackground" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>