# ⚡zap⚡ - blazingly fast backends
Zap is intended to become the [zig](https://ziglang.org) replacement for the
kind of REST APIs I used to write in [python](https://python.org) with
[Flask](https://flask.palletsprojects.com) and
[mongodb](https://www.mongodb.com), etc.
What I need for that is a blazingly fast, robust HTTP server that I can use with
zig. While facil.io supports TLS, I don't mind HTTPS. In production, I use
[nginx](https://www.nginx.com) as a reverse proxy anyway.
Zap wraps and patches [facil.io - the C web application
framework](https://facil.io).
**⚡ZAP⚡ IS SUPER ALPHA**
Here's what works:
- **Super easy build process**: zag's `build.zig` fetches git sub-modules,
applies a patch to facil.io's logging for microsecond precision, builds and
optionally runs everything.
- _tested on Linux and macOS (arm, M1)_
- **[hello](examples/hello/hello.zig)**: welcomes you with some static
HTML
- **[routes](examples/routes/routes.zig)**: a super easy example
dispatching on the HTTP path
- **[serve](examples/serve/serve.zig)**: the traditional static web
server with optional dynamic request handling
- **[hello_json](examples/hello_json/hello_json.zig)**: serves you json
dependent on HTTP path
- **[endpoints](examples/endpoints/)**: a simple JSON REST API example featuring
a `/users` endpoint for PUTting/DELETE-ing/GET-ting/POST-ing users and a
`/list` endpoint returning the entire user list on GET, together with a static
HTML frontend to play around with.
I'll continue wrapping more of facil.io's functionality and adding stuff to zap
to a point where I can use it as the JSON REST API backend for real research
projects, serving thousands of concurrent clients.
## Getting started
```shell
$ git clone https://github.com/renerocksai/zap.git
$ cd zap
$ zig build run-hello
$ # open http://localhost:3000 in your browser
```
... and open [http://localhost:3000](http://locahhost:3000) in your browser.
## Using ⚡zap⚡ in your own projects
If you don't have an existing zig project, create one like this:
```shell
$ mkdir zaptest && cd zaptest
$ zig init-exe
$ git init
```
With an existing zig project, adding zap to it is easy:
1. Add zap as a git submodule
2. Add zap to your `build.zig`
To add zap as a git submodule:
```shell
$ mkdir libs
$ git submodule add https://github.com/renerocksai/zap.git libs/zap
```
Then, add the following at the top of your `build.zig`:
```zig
const zap_builder = @import("./libs/zap/build.zig");
const zap = std.build.Pkg{
.name = "zap",
.source = std.build.FileSource{ .path = "./libs/zap/src/zap.zig" },
};
```
In the `build` function, add the following before `exe.install()`:
```zig
exe.addPackage(zap);
zap_builder.addZap(exe, "./libs/zap/") catch unreachable;
```
From then on, you can use the zap package in your project. Check out the examples to see how to use zap.
## Examples
You build and run the examples via:
```shell
$ zig build [EXAMPLE]
$ ./zig-out/bin/[EXAMPLE]
```
... where `[EXAMPLE]` is one of `hello`, `routes`, or `serve`.
Example: building and running the hello example:
```shell
$ zig build hello
$ ./zig-out/bin/hello
```
To just run an example, like `routes`, without generating an executable, run:
```shell
$ zig build run-[EXAMPLE]
```
Example: building and running the routes example:
```shell
$ zig build run-routes
```
### [hello](examples/hello/hello.zig)
```zig
const std = @import("std");
const zap = @import("zap");
fn on_request(r: zap.SimpleRequest) void {
if (r.path) |the_path| {
std.debug.print("PATH: {s}\n", .{the_path});
}
if (r.query) |the_query| {
std.debug.print("QUERY: {s}\n", .{the_query});
}
_ = r.sendBody("Hello from ZAP!!!
");
}
pub fn main() !void {
var listener = zap.SimpleHttpListener.init(.{
.port = 3000,
.on_request = on_request,
.log = false,
});
try listener.listen();
std.debug.print("Listening on 0.0.0.0:3000\n", .{});
// start worker threads
zap.start(.{
.threads = 2,
.workers = 2,
});
}
```
### [serve](examples/serve/serve.zig)
```zig
const std = @import("std");
const zap = @import("zap");
fn on_request(r: zap.SimpleRequest) void {
// TODO: send 404 response
_ = r.sendBody("404 - File not found
");
}
pub fn main() !void {
var listener = zap.SimpleHttpListener.init(.{
.port = 3000,
.on_request = on_request,
.public_folder = std.mem.span("examples/serve"),
.log = true,
});
try listener.listen();
std.debug.print("Listening on 0.0.0.0:3000\n", .{});
// start worker threads
zap.start(.{
.threads = 2,
.workers = 2,
});
}
```
### [routes](examples/routes/routes.zig)
```zig
const std = @import("std");
const zap = @import("zap");
fn dispatch_routes(r: zap.SimpleRequest) void {
// dispatch
if (r.path) |the_path| {
if (routes.get(the_path)) |foo| {
foo(r);
}
}
// or default: present menu
_ = r.sendBody(
\\
\\
\\ static
\\ dynamic
\\
\\
);
}
fn static_site(r: zap.SimpleRequest) void {
_ = r.sendBody("Hello from STATIC ZAP!
");
}
var dynamic_counter: i32 = 0;
fn dynamic_site(r: zap.SimpleRequest) void {
dynamic_counter += 1;
var buf: [128]u8 = undefined;
const filled_buf = std.fmt.bufPrintZ(
&buf,
"Hello # {d} from DYNAMIC ZAP!!!
",
.{dynamic_counter},
) catch "ERROR";
_ = r.sendBody(std.mem.span(filled_buf));
}
fn setup_routes(a: std.mem.Allocator) !void {
routes = std.StringHashMap(zap.SimpleHttpRequestFn).init(a);
try routes.put("/static", static_site);
try routes.put("/dynamic", dynamic_site);
}
var routes: std.StringHashMap(zap.SimpleHttpRequestFn) = undefined;
pub fn main() !void {
try setup_routes(std.heap.page_allocator);
var listener = zap.SimpleHttpListener.init(.{
.port = 3000,
.on_request = dispatch_routes,
.log = true,
});
try listener.listen();
std.debug.print("Listening on 0.0.0.0:3000\n", .{});
zap.start(.{
.threads = 2,
.workers = 2,
});
}
```
### [hello_json](examples/hello_json/hello_json.zig)
```zig
const std = @import("std");
const zap = @import("zap");
const User = struct {
first_name: ?[]const u8 = null,
last_name: ?[]const u8 = null,
};
fn on_request(r: zap.SimpleRequest) void {
if (!std.mem.eql(u8, r.method.?, "GET"))
return;
// /user/n
if (r.path) |the_path| {
if (the_path.len < 7 or !std.mem.startsWith(u8, the_path, "/user/"))
return;
const user_id: usize = @intCast(usize, the_path[6] - 0x30);
const user = users.get(user_id);
var json_to_send: []const u8 = undefined;
if (stringify(user, .{})) |json| {
json_to_send = json;
} else {
json_to_send = "null";
}
std.debug.print("<< json: {s}\n", .{json_to_send});
r.setContentType(.JSON);
_ = r.sendBody(json_to_send);
}
}
const UserMap = std.AutoHashMap(usize, User);
var users: UserMap = undefined;
fn setupUserData(a: std.mem.Allocator) !void {
users = UserMap.init(a);
try users.put(1, .{ .first_name = "renerocksai" });
try users.put(2, .{ .first_name = "Your", .last_name = "Mom" });
}
fn stringify(value: anytype, options: std.json.StringifyOptions) ?[]const u8 {
var buf: [100]u8 = undefined;
var fba = std.heap.FixedBufferAllocator.init(&buf);
var string = std.ArrayList(u8).init(fba.allocator());
if (std.json.stringify(value, options, string.writer())) {
return string.items;
} else |_| { // error
return null;
}
}
pub fn main() !void {
var a = std.heap.page_allocator;
try setupUserData(a);
var listener = zap.SimpleHttpListener.init(.{
.port = 3000,
.on_request = on_request,
.log = false,
});
try listener.listen();
std.debug.print("Listening on 0.0.0.0:3000\n", .{});
// start worker threads
zap.start(.{
.threads = 2,
.workers = 2,
});
}
```
### [endpoints](examples/endpoints/)
The following only shows the GET functionality implemented on both the `/user/`
and the `/list` endpoints. See [endpoints](examples/endpoints/) for a complete
example, including a HTML + JavaScript frontend.
[`main.zig`](examples/endpoints/main.zig):
```zig
const std = @import("std");
const zap = @import("zap");
const Endpoints = @import("endpoints.zig");
pub fn main() !void {
const allocator = std.heap.page_allocator;
// setup listener
var listener = zap.SimpleEndpointListener.init(
allocator,
.{
.port = 3000,
.on_request = null,
.log = true,
.public_folder = "./examples/endpoints/html",
},
);
Endpoints.init(allocator, "/user", "/list");
// add endpoints
try listener.addEndpoint(Endpoints.getUserEndpoint());
try listener.addEndpoint(Endpoints.getUserListEndpoint());
// fake some users
var uid: usize = undefined;
uid = try Endpoints.getUsers().addByName("renerocksai", null);
uid = try Endpoints.getUsers().addByName("renerocksai", "your mom");
// listen
try listener.listen();
std.debug.print("Listening on 0.0.0.0:3000\n", .{});
// and run
zap.start(.{
.threads = 2,
.workers = 2,
});
}
```
[`endpoints.zig`](examples/endpoints/endpoints.zig):
```zig
const std = @import("std");
const zap = @import("zap");
const Users = @import("users.zig");
const User = Users.User;
// the Endpoints
pub const Self = @This();
var alloc: std.mem.Allocator = undefined;
var endpoint: zap.SimpleEndpoint = undefined;
var list_endpoint: zap.SimpleEndpoint = undefined;
var users: Users = undefined;
pub fn init(
a: std.mem.Allocator,
user_path: []const u8,
userlist_path: []const u8,
) void {
users = Users.init(a);
alloc = a;
endpoint = zap.SimpleEndpoint.init(.{
.path = user_path,
.get = getUser,
.post = null,
.put = null,
.delete = null,
});
list_endpoint = zap.SimpleEndpoint.init(.{
.path = userlist_path,
.get = listUsers,
.post = null,
.put = null,
.delete = null,
});
}
pub fn getUsers() *Users {
return &users;
}
pub fn getUserEndpoint() *zap.SimpleEndpoint {
return &endpoint;
}
pub fn getUserListEndpoint() *zap.SimpleEndpoint {
return &list_endpoint;
}
fn userIdFromPath(path: []const u8) ?usize {
if (path.len >= endpoint.settings.path.len + 2) {
if (path[endpoint.settings.path.len] != '/') {
return null;
}
const idstr = path[endpoint.settings.path.len + 1 ..];
return std.fmt.parseUnsigned(usize, idstr, 10) catch null;
}
return null;
}
pub fn getUser(e: *zap.SimpleEndpoint, r: zap.SimpleRequest) void {
_ = e;
if (r.path) |path| {
if (userIdFromPath(path)) |id| {
if (users.get(id)) |user| {
if (zap.stringify(user, .{})) |json| {
_ = r.sendJson(json);
}
}
}
}
}
pub fn listUsers(e: *zap.SimpleEndpoint, r: zap.SimpleRequest) void {
_ = e;
var l: std.ArrayList(User) = std.ArrayList(User).init(alloc);
if (users.list(&l)) {} else |_| {
return;
}
if (zap.stringifyArrayList(std.ArrayList(User, &l, .{})) |maybe_json| {
if (maybe_json) |json| {
_ = r.sendJson(json);
}
} else |_| {
return;
}
}
```