Remove writer flushing from main CLI

* Refactor: Update build process and improve memory management

- Commented out library tests in build.zig for clarity.
- Changed minimum Zig version to 0.15.1 in build.zig.zon.
- Modified root.zig to accept a Writer for output instead of using log.
- Updated bandwidth.zig tests to use std.Thread.sleep for consistency.
- Adjusted fast.zig to improve memory allocation handling.
- Enhanced http_latency_tester.zig to manage latencies with allocator.
- Refined speed_worker.zig to utilize std.Thread.sleep for delays.
- Improved measurement_strategy.zig to handle speed measurements with allocator.
- Updated main.zig to flush writer after command execution.

* Fix: Update zli dependency to use URL and hash instead of path

* Fix: Add newline to spinner output for better readability

* switch worksflows to using zig 0.15.1

---------

Co-authored-by: mikkelam <mikkelarm@gmail.com>

.github/workflows/ci.yml

@@ -13,6 +13,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: mlugg/setup-zig@v2
+        with:
+          version: 0.15.2
       - run: zig build test
       - run: zig fmt --check src/
 
@@ -28,12 +30,16 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: mlugg/setup-zig@v2
+        with:
+          version: 0.15.2
       - name: Build ${{ matrix.target }} (${{ matrix.optimize }})
         run: |
           zig build --release=${{ matrix.optimize == 'ReleaseSafe' && 'safe' || 'off' }} -Dtarget=${{ matrix.target }}
 
-      - name: Verify binary
+      - name: Test help command
         if: matrix.target == 'x86_64-linux'
-        run: |
-          ./zig-out/bin/fast-cli --help
-          file zig-out/bin/fast-cli
+        run: ./zig-out/bin/fast-cli --help
+
+      - name: Check binary type
+        if: matrix.target == 'x86_64-linux'
+        run: file zig-out/bin/fast-cli

.github/workflows/release.yml

@@ -19,9 +19,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: mlugg/setup-zig@v2
+        with:
+          version: 0.15.2
 
       - name: Build
-        run: zig build --release=safe -Dtarget=${{ matrix.target }}
+        run: zig build -Doptimize=ReleaseFast -Dtarget=${{ matrix.target }} -Dcpu=baseline
 
       - name: Prepare artifact
         run: |
@@ -39,6 +41,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: mlugg/setup-zig@v2
+        with:
+          version: 0.15.2
       - run: zig build test
 
   release:

README.md

@@ -6,7 +6,7 @@
 
 A blazingly fast CLI tool for testing internet speed uses fast.com v2 api. Written in Zig for maximum performance.
 
-⚡ **1.4 MiB binary** • 🚀 **Zero runtime deps** • 📊 **Smart stability detection**
+⚡ **1.2 MB binary** • 🚀 **Zero runtime deps** • 📊 **Smart stability detection**
 
 ## Demo
 
@@ -14,7 +14,7 @@ A blazingly fast CLI tool for testing internet speed uses fast.com v2 api. Writt
 
 ## Why fast-cli?
 
-- **Tiny binary**: Just 1.2 MiB, no runtime dependencies
+- **Tiny binary**: Just 1.2 MB, no runtime dependencies
 - **Blazing fast**: Concurrent connections with adaptive chunk sizing
 - **Cross-platform**: Single binary for Linux, macOS
 - **Smart stopping**: Uses Coefficient of Variation (CoV) algorithm for adaptive test duration
@@ -89,7 +89,8 @@ zig build
 zig build test
 
 # Release build
-zig build --release=safe
+# Consider removing -Dcpu if you do not need a portable build
+zig build -Doptimize=ReleaseFast -Dcpu=baseline
 ```
 
 ## License

build.zig

@@ -4,57 +4,31 @@ pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
 
-    // library tests
-    const library_tests = b.addTest(.{
-        .root_source_file = b.path("src/test.zig"),
-        .target = target,
-        .optimize = optimize,
-    });
-    const run_library_tests = b.addRunArtifact(library_tests);
+    const dep_zli = b.dependency("zli", .{ .target = target });
+    const dep_mvzr = b.dependency("mvzr", .{ .target = target, .optimize = optimize });
 
-    const test_step = b.step("test", "Run all tests");
-    test_step.dependOn(&run_library_tests.step);
-
-    const dep_zli = b.dependency("zli", .{
-        .target = target,
-    });
-    const mod_zli = dep_zli.module("zli");
-
-    const dep_mvzr = b.dependency("mvzr", .{
-        .target = target,
-        .optimize = optimize,
-    });
-    const mod_mvzr = dep_mvzr.module("mvzr");
-
-    // Create build options for version info
     const build_options = b.addOptions();
-
-    // Read version from build.zig.zon at compile time
     const build_zon_content = @embedFile("build.zig.zon");
     const version = blk: {
-        // Simple parsing to extract version string
         const start = std.mem.indexOf(u8, build_zon_content, ".version = \"") orelse unreachable;
         const version_start = start + ".version = \"".len;
         const end = std.mem.indexOfPos(u8, build_zon_content, version_start, "\"") orelse unreachable;
         break :blk build_zon_content[version_start..end];
     };
-
     build_options.addOption([]const u8, "version", version);
 
     const exe = b.addExecutable(.{
         .name = "fast-cli",
-        .root_source_file = b.path("src/main.zig"),
-        .target = target,
-        .optimize = optimize,
-        .strip = optimize != .Debug,
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("src/main.zig"),
+            .target = target,
+            .optimize = optimize,
+        }),
     });
 
-    exe.root_module.addImport("zli", mod_zli);
-    exe.root_module.addImport("mvzr", mod_mvzr);
+    exe.root_module.addImport("zli", dep_zli.module("zli"));
+    exe.root_module.addImport("mvzr", dep_mvzr.module("mvzr"));
     exe.root_module.addImport("build_options", build_options.createModule());
-    library_tests.root_module.addImport("mvzr", mod_mvzr);
-
-    // Link against the static library instead
 
     b.installArtifact(exe);
 
@@ -67,5 +41,15 @@ pub fn build(b: *std.Build) void {
     const run_step = b.step("run", "Run the app");
     run_step.dependOn(&run_cmd.step);
 
-    // b.default_step.dependOn(test_step); // Disabled for cross-compilation
+    const tests = b.addTest(.{
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("src/test.zig"),
+            .target = target,
+            .optimize = optimize,
+        }),
+    });
+    tests.root_module.addImport("mvzr", dep_mvzr.module("mvzr"));
+
+    const test_step = b.step("test", "Run tests");
+    test_step.dependOn(&b.addRunArtifact(tests).step);
 }

build.zig.zon

@@ -1,20 +1,20 @@
 .{
     .name = .fast_cli,
 
-    .version = "0.2.3",
+    .version = "0.2.4",
 
-    .fingerprint = 0xfb5a9fbee5075971, // Changing this has security and trust implications.
+    .fingerprint = 0xfb5a9fbee5075971,
 
-    .minimum_zig_version = "0.14.0",
+    .minimum_zig_version = "0.15.1",
 
     .dependencies = .{
-        .mvzr = .{
-            .url = "https://github.com/mnemnion/mvzr/archive/refs/tags/v0.3.3.tar.gz",
-            .hash = "mvzr-0.3.2-ZSOky95lAQA00lXTN_g8JWoBuh8pw-jyzmCWAqlu1h8L",
-        },
         .zli = .{
-            .url = "https://github.com/xcaeser/zli/archive/v3.7.0.tar.gz",
-            .hash = "zli-3.7.0-LeUjpq8uAQCl8uh-ws3jdXsnbCwMZQgcZQx4TVXHLSeQ",
+            .url = "https://github.com/xcaeser/zli/archive/v4.1.1.tar.gz",
+            .hash = "zli-4.1.1-LeUjpljfAAAak_E3L4NPowuzPs_FUF9-jYyxuTSNSthM",
+        },
+        .mvzr = .{
+            .url = "https://github.com/mnemnion/mvzr/archive/refs/tags/v0.3.7.tar.gz",
+            .hash = "mvzr-0.3.7-ZSOky5FtAQB2VrFQPNbXHQCFJxWTMAYEK7ljYEaMR6jt",
         },
     },
     .paths = .{

src/cli/root.zig

@@ -1,6 +1,9 @@
 const std = @import("std");
 const zli = @import("zli");
 const builtin = @import("builtin");
+const Writer = std.Io.Writer;
+
+const log = std.log.scoped(.cli);
 
 const Fast = @import("../lib/fast.zig").Fast;
 const HTTPSpeedTester = @import("../lib/http_speed_tester_v2.zig").HTTPSpeedTester;
@@ -11,7 +14,6 @@ const BandwidthMeter = @import("../lib/bandwidth.zig");
 const SpeedMeasurement = @import("../lib/bandwidth.zig").SpeedMeasurement;
 const progress = @import("../lib/progress.zig");
 const HttpLatencyTester = @import("../lib/http_latency_tester.zig").HttpLatencyTester;
-const log = std.log.scoped(.cli);
 
 const https_flag = zli.Flag{
     .name = "https",
@@ -44,8 +46,8 @@ const max_duration_flag = zli.Flag{
     .default_value = .{ .Int = 30 },
 };
 
-pub fn build(allocator: std.mem.Allocator) !*zli.Command {
-    const root = try zli.Command.init(allocator, .{
+pub fn build(writer: *Writer, allocator: std.mem.Allocator) !*zli.Command {
+    const root = try zli.Command.init(writer, allocator, .{
         .name = "fast-cli",
         .description = "Estimate connection speed using fast.com",
         .version = null,
@@ -65,6 +67,8 @@ fn run(ctx: zli.CommandContext) !void {
     const json_output = ctx.flag("json", bool);
     const max_duration = ctx.flag("duration", i64);
 
+    const spinner = ctx.spinner;
+
     log.info("Config: https={}, upload={}, json={}, max_duration={}s", .{
         use_https, check_upload, json_output, max_duration,
     });
@@ -74,20 +78,20 @@ fn run(ctx: zli.CommandContext) !void {
 
     const urls = fast.get_urls(5) catch |err| {
         if (!json_output) {
-            try ctx.spinner.fail("Failed to get URLs: {}", .{err});
+            try spinner.fail("Failed to get URLs: {}", .{err});
         } else {
             const error_msg = switch (err) {
                 error.ConnectionTimeout => "Failed to contact fast.com servers",
                 else => "Failed to get URLs",
             };
-            try outputJson(null, null, null, error_msg);
+            try outputJson(ctx.writer, null, null, null, error_msg);
         }
         return;
     };
 
-    log.info("Got {} URLs", .{urls.len});
+    log.info("Got {} URLs\n", .{urls.len});
     for (urls) |url| {
-        log.debug("URL: {s}", .{url});
+        log.info("URL: {s}\n", .{url});
     }
 
     // Measure latency first
@@ -95,9 +99,9 @@ fn run(ctx: zli.CommandContext) !void {
     defer latency_tester.deinit();
 
     const latency_ms = if (!json_output) blk: {
-        try ctx.spinner.start(.{}, "Measuring latency...", .{});
+        try spinner.start("Measuring latency...", .{});
         const result = latency_tester.measureLatency(urls) catch |err| {
-            log.err("Latency test failed: {}", .{err});
+            try spinner.fail("Latency test failed: {}", .{err});
             break :blk null;
         };
         break :blk result;
@@ -106,7 +110,7 @@ fn run(ctx: zli.CommandContext) !void {
     };
 
     if (!json_output) {
-        try ctx.spinner.start(.{}, "Measuring download speed...", .{});
+        log.info("Measuring download speed...", .{});
     }
 
     // Initialize speed tester
@@ -126,15 +130,15 @@ fn run(ctx: zli.CommandContext) !void {
     const download_result = if (json_output) blk: {
         // JSON mode: clean output only
         break :blk speed_tester.measure_download_speed_stability(urls, criteria) catch |err| {
-            log.err("Download test failed: {}", .{err});
-            try outputJson(null, null, null, "Download test failed");
+            try spinner.fail("Download test failed: {}", .{err});
+            try outputJson(ctx.writer, null, null, null, "Download test failed");
             return;
         };
     } else blk: {
         // Interactive mode with spinner updates
-        const progressCallback = progress.createCallback(ctx.spinner, updateSpinnerText);
+        const progressCallback = progress.createCallback(spinner, updateSpinnerText);
         break :blk speed_tester.measureDownloadSpeedWithStabilityProgress(urls, criteria, progressCallback) catch |err| {
-            try ctx.spinner.fail("Download test failed: {}", .{err});
+            try spinner.fail("Download test failed: {}", .{err});
             return;
         };
     };
@@ -142,21 +146,21 @@ fn run(ctx: zli.CommandContext) !void {
     var upload_result: ?SpeedTestResult = null;
     if (check_upload) {
         if (!json_output) {
-            try ctx.spinner.start(.{}, "Measuring upload speed...", .{});
+            log.info("Measuring upload speed...", .{});
         }
 
         upload_result = if (json_output) blk: {
             // JSON mode: clean output only
             break :blk speed_tester.measure_upload_speed_stability(urls, criteria) catch |err| {
-                log.err("Upload test failed: {}", .{err});
-                try outputJson(download_result.speed.value, latency_ms, null, "Upload test failed");
+                try spinner.fail("Upload test failed: {}", .{err});
+                try outputJson(ctx.writer, download_result.speed.value, latency_ms, null, "Upload test failed");
                 return;
             };
         } else blk: {
             // Interactive mode with spinner updates
-            const uploadProgressCallback = progress.createCallback(ctx.spinner, updateUploadSpinnerText);
+            const uploadProgressCallback = progress.createCallback(spinner, updateUploadSpinnerText);
             break :blk speed_tester.measureUploadSpeedWithStabilityProgress(urls, criteria, uploadProgressCallback) catch |err| {
-                try ctx.spinner.fail("Upload test failed: {}", .{err});
+                try spinner.fail("Upload test failed: {}", .{err});
                 return;
             };
         };
@@ -166,36 +170,34 @@ fn run(ctx: zli.CommandContext) !void {
     if (!json_output) {
         if (latency_ms) |ping| {
             if (upload_result) |up| {
-                try ctx.spinner.succeed("🏓 {d:.0}ms | ⬇️ Download: {d:.1} {s} | ⬆️ Upload: {d:.1} {s}", .{ ping, download_result.speed.value, download_result.speed.unit.toString(), up.speed.value, up.speed.unit.toString() });
+                try spinner.succeed("🏓 {d:.0}ms | ⬇️ Download: {d:.1} {s} | ⬆️ Upload: {d:.1} {s}", .{ ping, download_result.speed.value, download_result.speed.unit.toString(), up.speed.value, up.speed.unit.toString() });
             } else {
-                try ctx.spinner.succeed("🏓 {d:.0}ms | ⬇️ Download: {d:.1} {s}", .{ ping, download_result.speed.value, download_result.speed.unit.toString() });
+                try spinner.succeed("🏓 {d:.0}ms | ⬇️ Download: {d:.1} {s}", .{ ping, download_result.speed.value, download_result.speed.unit.toString() });
             }
         } else {
             if (upload_result) |up| {
-                try ctx.spinner.succeed("⬇️ Download: {d:.1} {s} | ⬆️ Upload: {d:.1} {s}", .{ download_result.speed.value, download_result.speed.unit.toString(), up.speed.value, up.speed.unit.toString() });
+                try spinner.succeed("⬇️ Download: {d:.1} {s} | ⬆️ Upload: {d:.1} {s}", .{ download_result.speed.value, download_result.speed.unit.toString(), up.speed.value, up.speed.unit.toString() });
             } else {
-                try ctx.spinner.succeed("⬇️ Download: {d:.1} {s}", .{ download_result.speed.value, download_result.speed.unit.toString() });
+                try spinner.succeed("⬇️ Download: {d:.1} {s}", .{ download_result.speed.value, download_result.speed.unit.toString() });
             }
         }
     } else {
         const upload_speed = if (upload_result) |up| up.speed.value else null;
-        try outputJson(download_result.speed.value, latency_ms, upload_speed, null);
+        try outputJson(ctx.writer, download_result.speed.value, latency_ms, upload_speed, null);
     }
 }
 
 /// Update spinner text with current speed measurement
 fn updateSpinnerText(spinner: anytype, measurement: SpeedMeasurement) void {
-    spinner.updateText("⬇️ {d:.1} {s}", .{ measurement.value, measurement.unit.toString() }) catch {};
+    spinner.updateMessage("⬇️ {d:.1} {s}", .{ measurement.value, measurement.unit.toString() }) catch {};
 }
 
 /// Update spinner text with current upload speed measurement
 fn updateUploadSpinnerText(spinner: anytype, measurement: SpeedMeasurement) void {
-    spinner.updateText("⬆️ {d:.1} {s}", .{ measurement.value, measurement.unit.toString() }) catch {};
+    spinner.updateMessage("⬆️ {d:.1} {s}", .{ measurement.value, measurement.unit.toString() }) catch {};
 }
 
-fn outputJson(download_mbps: ?f64, ping_ms: ?f64, upload_mbps: ?f64, error_message: ?[]const u8) !void {
-    const stdout = std.io.getStdOut().writer();
-
+fn outputJson(writer: *Writer, download_mbps: ?f64, ping_ms: ?f64, upload_mbps: ?f64, error_message: ?[]const u8) !void {
     var download_buf: [32]u8 = undefined;
     var ping_buf: [32]u8 = undefined;
     var upload_buf: [32]u8 = undefined;
@@ -206,5 +208,5 @@ fn outputJson(download_mbps: ?f64, ping_ms: ?f64, upload_mbps: ?f64, error_messa
     const upload_str = if (upload_mbps) |u| try std.fmt.bufPrint(&upload_buf, "{d:.1}", .{u}) else "null";
     const error_str = if (error_message) |e| try std.fmt.bufPrint(&error_buf, "\"{s}\"", .{e}) else "null";
 
-    try stdout.print("{{\"download_mbps\": {s}, \"ping_ms\": {s}, \"upload_mbps\": {s}, \"error\": {s}}}\n", .{ download_str, ping_str, upload_str, error_str });
+    try writer.print("{{\"download_mbps\": {s}, \"ping_ms\": {s}, \"upload_mbps\": {s}, \"error\": {s}}}\n", .{ download_str, ping_str, upload_str, error_str });
 }

src/lib/bandwidth.zig

@@ -107,7 +107,7 @@ test "BandwidthMeter bandwidth calculation" {
     meter.update_total(1000); // 1000 bytes
 
     // Sleep briefly to ensure time passes
-    std.time.sleep(std.time.ns_per_ms * 10); // 10ms
+    std.Thread.sleep(std.time.ns_per_ms * 10); // 10ms
 
     const bw = meter.bandwidth();
     try testing.expect(bw > 0);
@@ -127,7 +127,7 @@ test "BandwidthMeter unit conversion" {
     // Test different speed ranges
     meter._bytes_transferred = 1000;
     meter._timer = try std.time.Timer.start();
-    std.time.sleep(std.time.ns_per_s); // 1 second
+    std.Thread.sleep(std.time.ns_per_s); // 1 second
 
     const measurement = meter.bandwidthWithUnits();
 

src/lib/fast.zig

@@ -71,7 +71,7 @@ pub const Fast = struct {
 
         var result = try Fast.parse_response_urls(json_data.items, allocator);
 
-        return result.toOwnedSlice();
+        return result.toOwnedSlice(allocator);
     }
 
     /// Sanitizes JSON data by replacing invalid UTF-8 bytes that cause parseFromSlice to fail.
@@ -102,7 +102,7 @@ pub const Fast = struct {
     }
 
     fn parse_response_urls(json_data: []const u8, result_allocator: std.mem.Allocator) !std.ArrayList([]const u8) {
-        var result = std.ArrayList([]const u8).init(result_allocator);
+        var result = std.ArrayList([]const u8).empty;
 
         const sanitized_json = try sanitize_json(json_data, result_allocator);
         defer result_allocator.free(sanitized_json);
@@ -119,7 +119,7 @@ pub const Fast = struct {
 
         for (response.targets) |target| {
             const url_copy = try result_allocator.dupe(u8, target.url);
-            try result.append(url_copy);
+            try result.append(result_allocator, url_copy);
         }
 
         return result;
@@ -155,13 +155,13 @@ pub const Fast = struct {
     }
 
     fn get_page(self: *Fast, allocator: std.mem.Allocator, url: []const u8) !std.ArrayList(u8) {
-        _ = allocator;
-        var response_body = std.ArrayList(u8).init(self.arena.allocator());
+        var response_body = std.Io.Writer.Allocating.init(allocator);
 
         const response: http.Client.FetchResult = self.client.fetch(.{
             .method = .GET,
             .location = .{ .url = url },
-            .response_storage = .{ .dynamic = &response_body },
+            .response_writer = &response_body.writer,
+            // .response_storage = .{ .dynamic = &response_body },
         }) catch |err| switch (err) {
             error.NetworkUnreachable, error.ConnectionRefused => {
                 log.err("Failed to reach fast.com servers (network/connection error) for URL: {s}", .{url});
@@ -195,7 +195,7 @@ pub const Fast = struct {
             log.err("HTTP request failed with status code {}", .{response.status});
             return error.HttpRequestFailed;
         }
-        return response_body;
+        return response_body.toArrayList();
     }
 };
 
@@ -205,12 +205,12 @@ test "parse_response_urls_v2" {
     ;
     const allocator = testing.allocator;
 
-    const urls = try Fast.parse_response_urls(response, allocator);
+    var urls = try Fast.parse_response_urls(response, allocator);
     defer {
         for (urls.items) |url| {
             allocator.free(url);
         }
-        urls.deinit();
+        urls.deinit(allocator);
     }
 
     try testing.expect(urls.items.len == 2);
@@ -275,12 +275,12 @@ test "parse_response_without_isp" {
     ;
     const allocator = testing.allocator;
 
-    const urls = try Fast.parse_response_urls(response, allocator);
+    var urls = try Fast.parse_response_urls(response, allocator);
     defer {
         for (urls.items) |url| {
             allocator.free(url);
         }
-        urls.deinit();
+        urls.deinit(allocator);
     }
 
     try testing.expect(urls.items.len == 1);
@@ -293,12 +293,12 @@ test "parse_response_minimal_client" {
     ;
     const allocator = testing.allocator;
 
-    const urls = try Fast.parse_response_urls(response, allocator);
+    var urls = try Fast.parse_response_urls(response, allocator);
     defer {
         for (urls.items) |url| {
             allocator.free(url);
         }
-        urls.deinit();
+        urls.deinit(allocator);
     }
 
     try testing.expect(urls.items.len == 1);

src/lib/http_latency_tester.zig

@@ -1,5 +1,6 @@
 const std = @import("std");
 const http = std.http;
+const log = std.log.scoped(.cli);
 
 pub const HttpLatencyTester = struct {
     allocator: std.mem.Allocator,
@@ -18,16 +19,22 @@ pub const HttpLatencyTester = struct {
 
     /// Measure latency to multiple URLs using HEAD requests
     /// Returns median latency in milliseconds, or null if all requests failed
+    /// Zig's http client seems to be ~20ms slower than curl.
+    /// Let's not worry about that misreporting for now
     pub fn measureLatency(self: *Self, urls: []const []const u8) !?f64 {
         if (urls.len == 0) return null;
 
-        var latencies = std.ArrayList(f64).init(self.allocator);
-        defer latencies.deinit();
+        var latencies: std.ArrayList(f64) = .{};
+        defer latencies.deinit(self.allocator);
+
+        // HTTP client for all requests
+        var client = http.Client{ .allocator = self.allocator };
+        defer client.deinit();
 
         // Test each URL
         for (urls) |url| {
-            if (self.measureSingleUrl(url)) |latency_ms| {
-                try latencies.append(latency_ms);
+            if (self.measureSingleUrl(url, &client)) |latency_ms| {
+                try latencies.append(self.allocator, latency_ms);
             } else |_| {
                 // Ignore errors, continue with other URLs
                 continue;
@@ -36,50 +43,26 @@ pub const HttpLatencyTester = struct {
 
         if (latencies.items.len == 0) return null;
 
+        log.info("Latencies: {any}", .{latencies.items});
+
         // Return median latency
         return self.calculateMedian(latencies.items);
     }
 
-    /// Measure latency to a single URL using connection reuse method
-    /// First request establishes HTTPS connection, second request measures pure RTT
-    fn measureSingleUrl(self: *Self, url: []const u8) !f64 {
-        var client = http.Client{ .allocator = self.allocator };
-        defer client.deinit();
+    /// Measure latency to a single URL using HEAD request
+    fn measureSingleUrl(self: *Self, url: []const u8, client: *http.Client) !f64 {
+        _ = self;
 
         // Parse URL
         const uri = try std.Uri.parse(url);
 
-        // First request: Establish HTTPS connection (ignore timing)
-        {
-            const server_header_buffer = try self.allocator.alloc(u8, 4096);
-            defer self.allocator.free(server_header_buffer);
-
-            var req = try client.open(.HEAD, uri, .{
-                .server_header_buffer = server_header_buffer,
-            });
-            defer req.deinit();
-
-            try req.send();
-            try req.finish();
-            try req.wait();
-        }
-
-        // Second request: Reuse connection and measure pure HTTP RTT
+        // Measure request/response timing
         const start_time = std.time.nanoTimestamp();
 
-        {
-            const server_header_buffer = try self.allocator.alloc(u8, 4096);
-            defer self.allocator.free(server_header_buffer);
-
-            var req = try client.open(.HEAD, uri, .{
-                .server_header_buffer = server_header_buffer,
-            });
-            defer req.deinit();
-
-            try req.send();
-            try req.finish();
-            try req.wait();
-        }
+        _ = try client.fetch(.{
+            .method = .HEAD,
+            .location = .{ .uri = uri },
+        });
 
         const end_time = std.time.nanoTimestamp();
 

src/lib/http_speed_tester_v2.zig

@@ -154,7 +154,7 @@ pub const HTTPSpeedTester = struct {
 
         // Main measurement loop
         while (strategy.shouldContinue(timer.timer_interface().read())) {
-            std.time.sleep(strategy.getSleepInterval());
+            std.Thread.sleep(strategy.getSleepInterval());
 
             if (has_progress) {
                 const current_bytes = worker_manager.getCurrentDownloadBytes(workers);
@@ -221,7 +221,7 @@ pub const HTTPSpeedTester = struct {
 
         // Main measurement loop
         while (strategy.shouldContinue(timer.timer_interface().read())) {
-            std.time.sleep(strategy.getSleepInterval());
+            std.Thread.sleep(strategy.getSleepInterval());
 
             if (has_progress) {
                 const current_bytes = worker_manager.getCurrentUploadBytes(workers);
@@ -285,7 +285,7 @@ pub const HTTPSpeedTester = struct {
 
         // Main measurement loop
         while (strategy.shouldContinue(timer.timer_interface().read())) {
-            std.time.sleep(strategy.getSleepInterval());
+            std.Thread.sleep(strategy.getSleepInterval());
 
             const current_bytes = worker_manager.getCurrentDownloadBytes(workers);
 
@@ -359,7 +359,7 @@ pub const HTTPSpeedTester = struct {
 
         // Main measurement loop
         while (strategy.shouldContinue(timer.timer_interface().read())) {
-            std.time.sleep(strategy.getSleepInterval());
+            std.Thread.sleep(strategy.getSleepInterval());
 
             const current_bytes = worker_manager.getCurrentUploadBytes(workers);
 

src/lib/measurement_strategy.zig

@@ -31,6 +31,7 @@ pub const StabilityStrategy = struct {
     last_sample_time: u64 = 0,
     last_total_bytes: u64 = 0,
     consecutive_stable_checks: u32 = 0,
+    allocator: std.mem.Allocator,
 
     pub fn init(allocator: std.mem.Allocator, criteria: StabilityCriteria) StabilityStrategy {
         return StabilityStrategy{
@@ -38,12 +39,13 @@ pub const StabilityStrategy = struct {
             .ramp_up_duration_ns = @as(u64, criteria.ramp_up_duration_seconds) * std.time.ns_per_s,
             .max_duration_ns = @as(u64, criteria.max_duration_seconds) * std.time.ns_per_s,
             .measurement_interval_ns = criteria.measurement_interval_ms * std.time.ns_per_ms,
-            .speed_measurements = std.ArrayList(f64).init(allocator),
+            .speed_measurements = std.ArrayList(f64).empty,
+            .allocator = allocator,
         };
     }
 
     pub fn deinit(self: *StabilityStrategy) void {
-        self.speed_measurements.deinit();
+        self.speed_measurements.deinit(self.allocator);
     }
 
     pub fn shouldContinue(self: StabilityStrategy, current_time: u64) bool {
@@ -69,7 +71,7 @@ pub const StabilityStrategy = struct {
 
             // Phase 1: Ramp-up - collect measurements but don't check stability
             if (current_time < self.ramp_up_duration_ns) {
-                try self.speed_measurements.append(interval_speed);
+                try self.speed_measurements.append(self.allocator, interval_speed);
 
                 // Keep sliding window size
                 if (self.speed_measurements.items.len > self.criteria.sliding_window_size) {
@@ -77,7 +79,7 @@ pub const StabilityStrategy = struct {
                 }
             } else {
                 // Phase 2: Stabilization - check CoV for stability
-                try self.speed_measurements.append(interval_speed);
+                try self.speed_measurements.append(self.allocator, interval_speed);
 
                 // Maintain sliding window
                 if (self.speed_measurements.items.len > self.criteria.sliding_window_size) {

src/lib/workers/speed_worker.zig

@@ -169,7 +169,7 @@ pub const DownloadWorker = struct {
                     _ = self.error_count.fetchAdd(1, .monotonic);
                     break;
                 }
-                std.time.sleep(std.time.ns_per_ms * 100);
+                std.Thread.sleep(std.time.ns_per_ms * 100);
                 continue;
             };
             defer response.deinit();
@@ -183,7 +183,7 @@ pub const DownloadWorker = struct {
             // Accept both 200 (full content) and 206 (partial content)
             if (response.status != .ok and response.status != .partial_content) {
                 print("Worker {} HTTP error: {}\n", .{ self.config.worker_id, response.status });
-                std.time.sleep(std.time.ns_per_ms * 100);
+                std.Thread.sleep(std.time.ns_per_ms * 100);
                 continue;
             }
 
@@ -196,7 +196,7 @@ pub const DownloadWorker = struct {
 
             // Small delay between requests
             if (self.config.delay_between_requests_ms > 0) {
-                std.time.sleep(std.time.ns_per_ms * self.config.delay_between_requests_ms);
+                std.Thread.sleep(std.time.ns_per_ms * self.config.delay_between_requests_ms);
             }
         }
     }
@@ -318,7 +318,7 @@ pub const UploadWorker = struct {
                     _ = self.error_count.fetchAdd(1, .monotonic);
                     break;
                 }
-                std.time.sleep(std.time.ns_per_ms * 100);
+                std.Thread.sleep(std.time.ns_per_ms * 100);
                 continue;
             };
             defer response.deinit();
@@ -331,7 +331,7 @@ pub const UploadWorker = struct {
 
             if (response.status != .ok) {
                 print("Upload worker {} HTTP error: {}\n", .{ self.config.worker_id, response.status });
-                std.time.sleep(std.time.ns_per_ms * 100);
+                std.Thread.sleep(std.time.ns_per_ms * 100);
                 continue;
             }
 
@@ -404,15 +404,14 @@ pub const RealHttpClient = struct {
     fn fetch(ptr: *anyopaque, request: FetchRequest) !FetchResponse {
         const self: *Self = @ptrCast(@alignCast(ptr));
 
-        var response_body = std.ArrayList(u8).init(self.allocator);
+        var response_body = std.Io.Writer.Allocating.init(self.allocator);
         errdefer response_body.deinit();
 
         const fetch_options = http.Client.FetchOptions{
             .method = request.method,
             .location = .{ .url = request.url },
             .payload = if (request.payload) |p| p else null,
-            .response_storage = .{ .dynamic = &response_body },
-            .max_append_size = request.max_response_size,
+            .response_writer = &response_body.writer,
         };
 
         const result = try self.client.fetch(fetch_options);
@@ -469,7 +468,7 @@ pub const MockHttpClient = struct {
     pub fn init(allocator: std.mem.Allocator) Self {
         return Self{
             .allocator = allocator,
-            .responses = std.ArrayList(FetchResponse).init(allocator),
+            .responses = std.ArrayList(FetchResponse).empty,
             .request_count = std.atomic.Value(u32).init(0),
         };
     }
@@ -478,12 +477,12 @@ pub const MockHttpClient = struct {
         for (self.responses.items) |*response| {
             self.allocator.free(response.body);
         }
-        self.responses.deinit();
+        self.responses.deinit(self.allocator);
     }
 
     pub fn addResponse(self: *Self, status: http.Status, body: []const u8) !void {
         const body_copy = try self.allocator.dupe(u8, body);
-        try self.responses.append(FetchResponse{
+        try self.responses.append(self.allocator, FetchResponse{
             .status = status,
             .body = body_copy,
             .allocator = self.allocator,
@@ -505,7 +504,7 @@ pub const MockHttpClient = struct {
         _ = request;
 
         if (self.delay_ms > 0) {
-            std.time.sleep(std.time.ns_per_ms * self.delay_ms);
+            std.Thread.sleep(std.time.ns_per_ms * self.delay_ms);
         }
 
         if (self.should_fail) {
@@ -611,7 +610,7 @@ test "DownloadWorker basic functionality" {
     const thread = try std.Thread.spawn(.{}, DownloadWorker.run, .{&worker});
 
     // Let it run for a bit
-    std.time.sleep(std.time.ns_per_ms * 100);
+    std.Thread.sleep(std.time.ns_per_ms * 100);
 
     // Advance timer to trigger stop
     mock_timer.setTime(std.time.ns_per_s * 3); // 3 seconds

src/main.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+
 const cli = @import("cli/root.zig");
 
 pub const std_options: std.Options = .{
@@ -11,7 +12,11 @@ pub const std_options: std.Options = .{
 
 pub fn main() !void {
     const allocator = std.heap.smp_allocator;
-    var root = try cli.build(allocator);
+
+    const file = std.fs.File.stdout();
+    var writer = file.writerStreaming(&.{}).interface;
+
+    const root = try cli.build(&writer, allocator);
     defer root.deinit();
 
     try root.execute(.{});