src/server/main.zig

@@ -1,47 +1,39 @@
 const std = @import("std");
-const Message = @import("./message_parser.zig");
+const Message = @import("./message_parser.zig").Message;
+pub const ServerInfo = Message.ServerInfo;
 
-const ClientState = @import("./client.zig");
+const ClientState = @import("./client.zig").ClientState;
+const Server = @This();
 
-pub const ServerInfo = struct {
-    /// The unique identifier of the NATS server.
-    server_id: []const u8,
-    /// The name of the NATS server.
-    server_name: []const u8,
-    /// The version of NATS.
-    version: []const u8,
-    /// The version of golang the NATS server was built with.
-    go: []const u8 = "0.0.0",
-    /// The IP address used to start the NATS server,
-    /// by default this will be 0.0.0.0 and can be
-    /// configured with -client_advertise host:port.
-    host: []const u8 = "0.0.0.0",
-    /// The port number the NATS server is configured
-    /// to listen on.
-    port: u16 = 4222,
-    /// Whether the server supports headers.
-    headers: bool = false,
-    /// Maximum payload size, in bytes, that the server
-    /// will accept from the client.
-    max_payload: u64,
-    /// An integer indicating the protocol version of
-    /// the server. The server version 1.2.0 sets this
-    /// to 1 to indicate that it supports the "Echo"
-    /// feature.
-    proto: u32 = 1,
-};
+info: ServerInfo,
+clients: std.AutoHashMapUnmanaged(usize, ClientState) = .empty,
+/// Map of subjects to a map of (client ID => SID)
+subscriptions: std.StringHashMapUnmanaged(std.AutoHashMapUnmanaged(usize, []const u8)) = .empty,
 
-server_info: ServerInfo,
-clients: std.AutoHashMapUnmanaged(u64, ClientState) = .empty,
-/// Map of subjects to client IDs that are subscribed to that subject.
-subscriptions: std.StringHashMapUnmanaged(std.ArrayList(u64)),
+pub fn main(gpa: std.mem.Allocator, server_config: ServerInfo) !void {
+    var server: Server = .{
+        .info = server_config,
+    };
 
-pub fn main(gpa: std.mem.Allocator, main_args: anytype) !void {
-    _ = gpa;
-    _ = main_args;
+    var threaded: std.Io.Threaded = .init(gpa);
+    defer threaded.deinit();
+    const io = threaded.io();
+
+    var tcp_server = try std.Io.net.IpAddress.listen(try std.Io.net.IpAddress.parse(
+        server.info.host,
+        server.info.port,
+    ), io, .{});
+    defer tcp_server.deinit(io);
+
+    var id: usize = 0;
+    while (true) : (id +%= 1) {
+        if (server.clients.contains(id)) continue;
+        const stream = try tcp_server.accept(io);
+        _ = io.async(handleConnection, .{ gpa, io, id, stream, &server });
+    }
 }
 
-fn handleConnection(allocator: std.mem.Allocator, io: std.Io, stream: std.Io.net.Stream, info: ServerInfo) void {
+fn handleConnection(allocator: std.mem.Allocator, io: std.Io, id: usize, stream: std.Io.net.Stream, server: *Server) !void {
     defer stream.close(io);
     var w_buffer: [1024]u8 = undefined;
     var writer = stream.writer(io, &w_buffer);
@@ -51,42 +43,169 @@ fn handleConnection(allocator: std.mem.Allocator, io: std.Io, stream: std.Io.net
     var reader = stream.reader(io, &r_buffer);
     const in = &reader.interface;
 
-    processClient(allocator, in, out, info) catch |err| {
+    writeInfo(out, server.info) catch return;
+    var connect_arena: std.heap.ArenaAllocator = .init(allocator);
+    defer connect_arena.deinit();
+    const connect = (Message.next(connect_arena.allocator(), in) catch return).connect;
+    var client_state: ClientState = .init(id, connect);
+
+    // server.clients.lockPointers();
+    try server.clients.put(allocator, id, client_state);
+    // server.clients.unlockPointers();
+
+    // defer {
+    //     server.clients.lockPointers();
+    //     server.clients.remove(allocator, id);
+    //     server.clients.unlockPointers();
+    //     server.subscriptions.lockPointers();
+    //     var sub_iter = server.subscriptions.iterator();
+    //     var to_free: std.ArrayList(usize) = .empty;
+    //     defer to_free.deinit(allocator);
+    //     while (sub_iter.next()) |sub| {
+    //         while (std.simd.firstIndexOfValue(sub.value_ptr.*, id)) |i| {
+    //             sub.value_ptr.*.orderedRemove(i);
+    //         }
+    //         if (sub.value_ptr.items.len == 0) {
+    //             to_free.append(allocator, sub.index);
+    //         }
+    //     }
+    //     server.subscriptions.orderedRemoveAtMany(allocator, to_free.items);
+    //     server.subscriptions.unlockPointers();
+    // }
+
+    processClient(allocator, io, in, out, server, &client_state) catch |err| {
         std.debug.panic("Error processing client: {}\n", .{err});
     };
 }
 
-fn processClient(gpa: std.mem.Allocator, in: *std.Io.Reader, out: *std.Io.Writer, info: ServerInfo) !void {
-    try writeInfo(out, info);
+fn processClient(gpa: std.mem.Allocator, io: std.Io, in: *std.Io.Reader, out: *std.Io.Writer, server: *Server, client_state: *ClientState) !void {
+    var parse_task = io.async(parseMessages, .{ gpa, io, in, client_state });
+    defer if (parse_task.cancel(io)) {} else |err| {
+        std.debug.print("Error canceling parse_task for {d}: {any}", .{ client_state.id, err });
+    };
+    var write_task = io.async(writeMessages, .{ io, out, server.*, client_state });
+    defer if (write_task.cancel(io)) {} else |err| {
+        std.debug.print("Error canceling write_task for {d}: {any}", .{ client_state.id, err });
+    };
 
-    var client_state_arena: std.heap.ArenaAllocator = .init(gpa);
-    defer client_state_arena.deinit();
-    const client_state = (try Message.next(client_state_arena.allocator(), in)).connect;
-    _ = client_state;
-
-    var message_parsing_arena: std.heap.ArenaAllocator = .init(gpa);
-    defer message_parsing_arena.deinit();
-    const message_parsing_allocator = message_parsing_arena.allocator();
-    while (true) {
-        defer _ = message_parsing_arena.reset(.retain_capacity);
-        const next_message = Message.next(message_parsing_allocator, in) catch |err| {
-            switch (err) {
-                error.EndOfStream => {
-                    break;
+    while (!io.cancelRequested()) {
+        if (client_state.send_queue.getOne(io)) |msg| {
+            switch (msg) {
+                // TODO: REMOVE
+                .not_real => {},
+                // Respond to ping with pong.
+                .ping => {
+                    try client_state.recv_queue.putOne(io, .pong);
                 },
-                else => {
-                    return err;
+                .@"pub" => |p| {
+                    std.debug.print("subs (in pub): {any}\n", .{server.subscriptions});
+                    std.debug.print("subs size: {d}\n", .{server.subscriptions.size});
+                    std.debug.print("subs subjects:\n", .{});
+                    var key_iter = server.subscriptions.keyIterator();
+                    while (key_iter.next()) |k| {
+                        std.debug.print("- {s}\n", .{k.*});
+                    } else std.debug.print("<none>\n", .{});
+                    std.debug.print("pub subject: '{s}'\n", .{p.subject});
+                    std.debug.print("pub: {any}\n", .{p});
+                    errdefer _ = client_state.recv_queue.put(io, &.{.@"-err"}, 1) catch {};
+                    // Just publishing to exact matches right now.
+                    // TODO: Publish to pattern matching subjects.
+                    if (server.subscriptions.get(p.subject)) |subs| {
+                        var subs_iter = subs.iterator();
+                        while (subs_iter.next()) |sub| {
+                            var client = server.clients.get(sub.key_ptr.*) orelse std.debug.panic("Trying to pub to a client that doesn't exist!\n", .{});
+                            std.debug.print("{d} is pubbing to {d}\n", .{ client_state.id, client.id });
+                            if ((try client.recv_queue.put(
+                                io,
+                                &.{
+                                    .{
+                                        .msg = .{
+                                            .subject = p.subject,
+                                            .sid = sub.value_ptr.*,
+                                            .reply_to = p.reply_to,
+                                            .payload = p.payload,
+                                        },
+                                    },
+                                },
+                                0,
+                            )) > 0) {
+                                std.debug.print("published message!\n", .{});
+                            } else {
+                                std.debug.print("skipped publishing for some reason\n", .{});
+                            }
+                        }
+                        try client_state.recv_queue.putOne(io, .@"+ok");
+                    } else {
+                        std.debug.print("no subs with subject\n", .{});
+                    }
+                },
+                .sub => |s| {
+                    var subscribers = try server.subscriptions.getOrPut(gpa, s.subject);
+                    if (!subscribers.found_existing) {
+                        subscribers.value_ptr.* = .empty;
+                    }
+                    try subscribers.value_ptr.*.put(gpa, client_state.id, s.sid);
+
+                    std.debug.print("subs: {any}\n", .{server.subscriptions});
+                },
+                .info => |info| {
+                    std.debug.panic("got an info message? : {any}\n", .{info});
+                },
+                else => |m| {
+                    std.debug.panic("Unimplemented: {any}\n", .{m});
                 },
             }
-        };
-        switch (next_message) {
-            .connect => |connect| {
-                std.debug.panic("Connection message after already connected: {any}\n", .{connect});
-            },
-            .ping => try writePong(out),
-            .@"pub" => try writeOk(out),
-            else => |msg| std.debug.panic("Message type not implemented: {any}\n", .{msg}),
-        }
+        } else |err| return err;
+    }
+
+    // while (true) {
+    //     switch (next_message) {
+    //         .connect => |connect| {
+    //             std.debug.panic("Connection message after already connected: {any}\n", .{connect});
+    //         },
+    //         .ping => try writePong(out),
+    //         .@"pub" => try writeOk(out),
+    //         else => |msg| std.debug.panic("Message type not implemented: {any}\n", .{msg}),
+    //     }
+    // }
+}
+
+fn parseMessages(gpa: std.mem.Allocator, io: std.Io, in: *std.Io.Reader, client_state: *ClientState) !void {
+    // var message_parsing_arena: std.heap.ArenaAllocator = .init();
+    // defer message_parsing_arena.deinit();
+    // const message_parsing_allocator = message_parsing_arena.allocator();
+
+    while (!io.cancelRequested()) {
+        // defer _ = message_parsing_arena.reset(.retain_capacity);
+        const next_message = // Message.next(message_parsing_allocator, in)
+            Message.next(gpa, in) catch |err| {
+                switch (err) {
+                    error.EndOfStream => {
+                        break;
+                    },
+                    else => {
+                        return err;
+                    },
+                }
+            };
+        std.debug.print("received message from client {d}: {any}\n'{s}'\n", .{ client_state.id, next_message, in.buffered() });
+        try client_state.send_queue.putOne(io, next_message);
+    }
+}
+
+fn writeMessages(io: std.Io, out: *std.Io.Writer, server: Server, client_state: *ClientState) !void {
+    while (true) {
+        std.debug.print("in writeMessage loop for {d}\n", .{client_state.id});
+        if (client_state.recv_queue.getOne(io)) |msg| {
+            std.debug.print("attempting to write message for {d}: {any}\n", .{ client_state.id, msg });
+            switch (msg) {
+                .@"+ok" => try writeOk(out),
+                .pong => try writePong(out),
+                .info => try writeInfo(out, server.info),
+                .msg => |m| try writeMsg(out, m),
+                else => std.debug.panic("unimplemented write", .{}),
+            }
+        } else |err| return err;
     }
 }
 
@@ -107,6 +226,21 @@ fn writeInfo(out: *std.Io.Writer, info: ServerInfo) !void {
     try out.flush();
 }
 
+fn writeMsg(out: *std.Io.Writer, msg: Message.Msg) !void {
+    std.debug.print("PRINTING MESSAGE\n\n\n\n", .{});
+    try out.print(
+        "MSG {s} {s} {s} {d}\r\n{s}\r\n",
+        .{
+            msg.subject,
+            msg.sid,
+            msg.reply_to orelse "",
+            msg.payload.len,
+            msg.payload,
+        },
+    );
+    try out.flush();
+}
+
 pub fn createId() []const u8 {
     return "SERVERID";
 }
@@ -114,3 +248,7 @@ pub fn createId() []const u8 {
 pub fn createName() []const u8 {
     return "SERVERNAME";
 }
+
+// test "handle pub" {
+//     const io = std.testing.io;
+// }