basic http (not TLS) app is unreasonably big

[blenessy]

Zig Version

0.11.0

Steps to Reproduce and Observed Behavior

Produced on Debian Bookworm (amd64).

Put the following in hello_http.zig:

// Based on : https://zigbyexample.github.io/http-client

const std = @import("std");
const allocator = std.heap.page_allocator;
const uri = std.Uri.parse("http://ftp.debian.org/debian/") catch unreachable;  // NOTE: http

pub fn main() !void {
    var client: std.http.Client = .{ .allocator = allocator };
    defer client.deinit();

    var req = try client.request(.GET, uri, .{ .allocator = allocator }, .{});
    defer req.deinit();
    try req.start();
    try req.wait();

    var buf: [1024]u8 = undefined;
    const stdout = std.io.getStdOut().writer();
    while (true) {
        const byte_count = try req.read(&buf);
        if (byte_count == 0) break;
        _ = try stdout.write(buf[0..byte_count]);
    }
}

compile it:

zig build-exe -O ReleaseSmall -fsingle-threaded hello_http.zig

note the size (in bytes) of the binary:

$ du -b hello_http
551448  hello_http

Expected Behavior

On the same system, save the following ziget based (TCP) based implementation to hello_ziget.zig:

const std = @import("std");

pub fn main() !void {
    var allocator = std.heap.page_allocator;

    var conn = try std.net.tcpConnectToHost(allocator, "ftp.debian.org", 80);
    defer conn.close();

    const msg = "GET /debian/ HTTP/1.1\r\nHost: ftp.debian.org\r\nConnection: close\r\n\r\n";
    _ = try conn.write(msg);

    var buf: [1024]u8 = undefined;
    const stdout = std.io.getStdOut().writer();
    while (true) {
        const byte_count = try conn.read(&buf);
        if (byte_count == 0) break;
        _ = try stdout.write(buf[0..byte_count]);
    }
}

compile it:

zig build-exe -O ReleaseSmall -fsingle-threaded hello_ziget.zig

note the size:

$ du -b hello_ziget
46472   hello_ziget

---

Conclusion

The std.http package brings in a lot dead code when only the HTTP protocol is used. The "dead code" in question is probably the TLS stack, which is clearly unused in http only use-cases.

551k vs 46k might be unimportant in some use-cases, but for IoT devices this is a deal-breaker.

[truemedian]

std.crypto.tls is currently tied into std.http together rather tightly. I'm not sure but I don't think any of the crypto stuff used in TLS has any optimizations for ReleaseSmall. A flag to disable TLS and optimizations for std.http in ReleaseSmall would both be good changes here.

[Ristovski]

Not to mention the compilation is drastically slower.
Reusing the same examples from OP issue:

First example (std.http.Client):

$ time zig build-exe test1.zig 

real	0m5.125s
user	0m4.795s
sys	0m0.358s

Second example (std.net.tcpConnectToHost):

 $ time zig build-exe test2.zig 

real	0m0.947s
user	0m0.875s
sys	0m0.100s