commit a whole bunch of changes before removing list form chirp in favor of external...

[chirp] / src / main.zig

diff --git a/src/main.zig b/src/main.zig
index 86820082c263626605b277a95a3cb954d80a4ef4..f5e66ea54fc0d264251b26eba1081b92bf26a959 100644 (file)
--- a/src/main.zig
+++ b/src/main.zig
@@ -7,11 +7,16 @@ const http = @import("http");
 const Prng = struct {
     var prng: std.Random.DefaultPrng = std.Random.DefaultPrng.init(0);
 
 const Prng = struct {
     var prng: std.Random.DefaultPrng = std.Random.DefaultPrng.init(0);
 

-    pub fn gen_id(dbi: anytype) Id {
-        var id = Prng.prng.next();
+    fn IdType(comptime T: type) type {
+        const ti = @typeInfo(@TypeOf(T.get));
+        return ti.Fn.params[1].type.?;
+    }
+
+    pub fn gen_id(dbi: anytype) IdType(@TypeOf(dbi)) {
+        var id: IdType(@TypeOf(dbi)) = @enumFromInt(Prng.prng.next());

 
         while (dbi.has(id)) {
 
         while (dbi.has(id)) {

-            id = Prng.prng.next();
+            id = @enumFromInt(Prng.prng.next());

         }
 
         return id;
         }
 
         return id;


@@ -39,14 +44,146 @@ const Prng = struct {
 };
 
 const Db = struct {
 };
 
 const Db = struct {

-    fn users(txn: *const lmdb.Txn) !lmdb.Dbi(Id, User) {
-        return try txn.dbi("users", Id, User);
+    fn Key(types: anytype) type {
+        return std.meta.Tuple(&types);
+    }
+    fn users(txn: *const lmdb.Txn) !lmdb.Dbi(UserId, User) {
+        return try txn.dbi("users", UserId, User);
+    }
+    fn user_ids(txn: *const lmdb.Txn) !lmdb.Dbi(Username, UserId) {
+        return try txn.dbi("user_ids", Username, UserId);
+    }
+    fn sessions(txn: *const lmdb.Txn) !lmdb.Dbi(SessionToken, UserId) {
+        return try txn.dbi("sessions", SessionToken, UserId);
+    }
+    fn posts(txn: *const lmdb.Txn) !lmdb.Dbi(PostId, Post) {
+        return try txn.dbi("posts", PostId, Post);
+    }
+    fn lists(txn: *const lmdb.Txn, comptime T: type) !lmdb.Dbi(ListId, ListNode(T)) {
+        return try txn.dbi("lists", ListId, ListNode(T));
+    }
+    fn sets(txn: *const lmdb.Txn, comptime T: type) !lmdb.Dbi(Key(.{ SetId, T }), u0) {
+        return try txn.dbi("sets", Key(.{ SetId, T }), u0);
+    }
+
+    const ListId = enum(u64) { _ };
+
+    pub fn ListNode(comptime T: type) type {
+        return struct {
+            next: ?ListId,
+            prev: ?ListId,
+            data: T,
+        };

     }
     }

-    fn user_ids(txn: *const lmdb.Txn) !lmdb.Dbi(Username, Id) {
-        return try txn.dbi("user_ids", Username, Id);
+
+    pub fn List(comptime T: type) type {
+        return struct {
+            const Self = @This();
+
+            first: ListId = undefined,
+            last: ListId = undefined,
+            len: usize = 0,
+
+            pub const Iterator = struct {
+                dbi: lmdb.Dbi(ListId, ListNode(T)),
+                id_maybe: ?ListId,
+
+                pub fn next(self: *Iterator) ?T {
+                    const id = self.id_maybe orelse return null;
+
+                    // TODO: how to handle this?
+                    const ln = self.dbi.get(id) orelse return null;
+                    self.id_maybe = ln.next;
+                    return ln.data;
+                }
+            };
+            pub fn it(self: *const Self, txn: *const lmdb.Txn) !Iterator {
+                const list = try Db.lists(txn, T);
+                return .{ .dbi = list, .id_maybe = if (self.len > 0) self.first else null };
+            }
+            pub fn append(self: *Self, txn: *const lmdb.Txn, t: T) !void {
+                const list = try Db.lists(txn, T);
+                const new_id = Prng.gen_id(list);
+
+                if (self.len == 0) {
+                    self.first = new_id;
+                    self.last = new_id;
+                    self.len = 1;
+                    list.put(new_id, .{
+                        .next = null,
+                        .prev = null,
+                        .data = t,
+                    });
+                } else {
+                    const prev_id = self.last;
+                    var last = list.get(prev_id).?;
+                    last.next = new_id;
+                    list.put(prev_id, last);
+
+                    list.put(new_id, .{
+                        .next = null,
+                        .prev = prev_id,
+                        .data = t,
+                    });
+
+                    self.last = new_id;
+                    self.len += 1;
+                }
+            }
+        };

     }
     }

-    fn sessions(txn: *const lmdb.Txn) !lmdb.Dbi(SessionToken, Id) {
-        return try txn.dbi("sessions", SessionToken, Id);
+
+    const SetId = enum(u64) { _ };
+
+    pub fn Set(comptime T: type) type {
+        return struct {
+            const Self = @This();
+            const SetKey = Key(.{ SetId, T });
+
+            len: usize = 0,
+            set_id: ?SetId = null,
+
+            pub fn init(self: *Self) void {
+                self.set_id = @enumFromInt(Prng.prng.next());
+            }
+
+            pub fn has(self: Self, txn: *const lmdb.Txn, t: T) !bool {
+                if (self.set_id == null) return false;
+
+                const set = try Db.sets(txn, T);
+                const key = SetKey{ self.set_id.?, t };
+
+                return set.has(key);
+            }
+
+            pub fn add(self: *Self, txn: *const lmdb.Txn, t: T) !void {
+                if (self.set_id == null) self.init();
+
+                const set = try Db.sets(txn, T);
+                const key = SetKey{ self.set_id.?, t };
+
+                if (!set.has(key)) {
+                    set.put(key, 0);
+                    if (set.has(key)) {
+                        self.len += 1;
+                    }
+                }
+            }
+
+            pub fn del(self: *Self, txn: *const lmdb.Txn, t: T) !void {
+                if (self.set_id == null) self.init();
+
+                const set = try Db.sets(txn, T);
+                const key = SetKey{ self.set_id.?, t };
+
+                if (set.has(key)) {
+                    set.del(key);
+                    if (!set.has(key)) {
+                        self.len -= 1;
+                    }
+                }
+            }
+        };

     }
 };
 
     }
 };
 


@@ -56,17 +193,44 @@ const Db = struct {
 
 const User = struct {
     // TODO: choose sizes
 
 const User = struct {
     // TODO: choose sizes

+    id: UserId,

     username: Username,
     password_hash: PasswordHash,
     username: Username,
     password_hash: PasswordHash,

+    posts: PostList = PostList{},
+};
+
+const Post = struct {
+    id: PostId,
+
+    user_id: UserId,
+    time: Timestamp,
+
+    upvotes: UserList = UserList{},
+    downvotes: UserList = UserList{},
+    comments: PostList = PostList{},
+    // reposts
+
+    text: PostText,

 };
 
 const SessionTokenLen = 16;
 
 const Id = u64;
 };
 
 const SessionTokenLen = 16;
 
 const Id = u64;

+const Login = struct {
+    user: User,
+    user_id: UserId,
+    session_token: SessionToken,
+};
+const UserId = enum(u64) { _ };
+const PostId = enum(u64) { _ };
+const Timestamp = i64;

 const Username = std.BoundedArray(u8, 16);
 const PasswordHash = std.BoundedArray(u8, 128);
 const SessionToken = [SessionTokenLen]u8;
 const CookieValue = std.BoundedArray(u8, 128);
 const Username = std.BoundedArray(u8, 16);
 const PasswordHash = std.BoundedArray(u8, 128);
 const SessionToken = [SessionTokenLen]u8;
 const CookieValue = std.BoundedArray(u8, 128);

+const PostText = std.BoundedArray(u8, 1024);
+const PostList = Db.List(PostId);
+const UserList = Db.Set(UserId);

 
 pub fn hash_password(password: []const u8) !PasswordHash {
     var hash_buffer = try PasswordHash.init(128);
 
 pub fn hash_password(password: []const u8) !PasswordHash {
     var hash_buffer = try PasswordHash.init(128);


@@ -118,6 +282,7 @@ pub fn register_user(env: *lmdb.Env, username: []const u8, password: []const u8)
     } else {
         const user_id = Prng.gen_id(users);
         users.put(user_id, User{
     } else {
         const user_id = Prng.gen_id(users);
         users.put(user_id, User{

+            .id = user_id,

             .username = username_array,
             .password_hash = try hash_password(password),
         });
             .username = username_array,
             .password_hash = try hash_password(password),
         });


@@ -167,31 +332,193 @@ fn logout_user(env: *lmdb.Env, session_token: SessionToken) !void {
     sessions.del(session_token);
 }
 
     sessions.del(session_token);
 }
 

-fn get_session_user(env: *lmdb.Env, session_token: SessionToken) !User {
+fn post(env: *lmdb.Env, user_id: UserId, text: []const u8) !void {
+    var post_id: PostId = undefined;
+
+    var txn = try env.txn();
+    {
+        const posts = try Db.posts(&txn);
+        post_id = Prng.gen_id(posts);
+        posts.put(post_id, Post{
+            .id = post_id,
+            .user_id = user_id,
+            .time = std.time.timestamp(),
+            .text = try PostText.fromSlice(text),
+        });
+
+        txn.commit();
+        env.sync();
+    }
+
+    txn = try env.txn();
+    {
+        const users = try Db.users(&txn);
+        var user = users.get(user_id) orelse return error.UserNotFound;
+        try user.posts.append(&txn, post_id);
+        users.put(user_id, user);
+
+        txn.commit();
+        env.sync();
+    }
+}
+
+fn vote(env: *lmdb.Env, post_id: PostId, user_id: UserId, dir: enum { Up, Down }) !void {
+    const txn = try env.txn();
+    defer {
+        txn.commit();
+        env.sync();
+    }
+
+    const posts = try Db.posts(&txn);
+
+    var p = posts.get(post_id) orelse return error.PostNotFound;
+    if (dir == .Up) {
+        try p.upvotes.add(&txn, user_id);
+    } else {
+        try p.downvotes.add(&txn, user_id);
+    }
+    posts.put(post_id, p);
+}
+
+fn unvote(env: *lmdb.Env, post_id: PostId, user_id: UserId, dir: enum { Up, Down }) !void {
+    const txn = try env.txn();
+    defer {
+        txn.commit();
+        env.sync();
+    }
+
+    const posts = try Db.posts(&txn);
+
+    var p = posts.get(post_id) orelse return error.PostNotFound;
+    if (dir == .Up) {
+        try p.upvotes.del(&txn, user_id);
+    } else {
+        try p.downvotes.del(&txn, user_id);
+    }
+    posts.put(post_id, p);
+}
+
+fn get_session_user_id(env: *lmdb.Env, session_token: SessionToken) !UserId {

     const txn = try env.txn();
     defer txn.abort();
 
     const sessions = try Db.sessions(&txn);
     const txn = try env.txn();
     defer txn.abort();
 
     const sessions = try Db.sessions(&txn);

-    const users = try Db.users(&txn);

 
     if (sessions.get(session_token)) |user_id| {
 
     if (sessions.get(session_token)) |user_id| {

-        return users.get(user_id) orelse error.UnknownUser;
+        return user_id;

     } else {
         return error.SessionNotFound;
     }
 }
 
     } else {
         return error.SessionNotFound;
     }
 }
 

+fn get_user(env: *lmdb.Env, user_id: UserId) !?User {
+    const txn = try env.txn();
+    defer txn.abort();
+
+    const users = try Db.users(&txn);
+    return users.get(user_id);
+}
+
+// }}}
+
+// html {{{
+fn html_form(res: *http.Response, comptime fmt_action: []const u8, args_action: anytype, inputs: anytype) !void {
+    try res.write("<form style=\"display: inline-block!important;\" action=\"", .{});
+    try res.write(fmt_action, args_action);
+    try res.write("\" method=\"post\">", .{});
+
+    inline for (inputs) |input| {
+        switch (@typeInfo(@TypeOf(input))) {
+            .Struct => {
+                try res.write("<input ", .{});
+                try res.write(input[0], input[1]);
+                try res.write(" />", .{});
+            },
+            else => {
+                try res.write("<input ", .{});
+                try res.write(input, .{});
+                try res.write(" />", .{});
+            },
+        }
+    }
+
+    try res.write("</form>", .{});
+}
+// }}}
+
+// write {{{
+fn write_header(res: *http.Response, logged_in: ?Login) !void {
+    if (logged_in) |login| {
+        try res.write(
+            \\<a href="/user/{s}">Home</a><br />
+        , .{login.user.username.constSlice()});
+        try html_form(res, "/logout", .{}, .{
+            \\type="submit" value="Logout"
+        });
+        try html_form(res, "/quit", .{}, .{
+            \\type="submit" value="Quit"
+        });
+        try res.write("<br />", .{});
+        try html_form(res, "/post", .{}, .{
+            \\type="text" name="text"
+            ,
+            \\type="submit" value="Post"
+        });
+    } else {
+        try res.write(
+            \\<a href="/">Home</a><br />
+            \\<a href="/register">Register</a>
+            \\<a href="/login">Login</a><br />
+        , .{});
+        try html_form(res, "/quit", .{}, .{
+            \\type="submit" value="Quit"
+        });
+    }
+}
+fn write_posts(res: *http.Response, txn: *const lmdb.Txn, user: User, login: ?Login) !void {
+    const posts = try Db.posts(txn);
+    var it = try user.posts.it(txn);
+    while (it.next()) |post_id| {
+        const p = posts.get(post_id) orelse break;
+        try res.write(
+            \\<div>
+            \\<p>{s}</p>
+        , .{p.text.constSlice()});
+        if (login != null and try p.upvotes.has(txn, login.?.user_id)) {
+            try html_form(res, "/unupvote/{}", .{@intFromEnum(post_id)}, .{
+                .{ "type=\"submit\" value=\"&#x2B06; {}\"", .{p.upvotes.len} },
+            });
+        } else {
+            try html_form(res, "/upvote/{}", .{@intFromEnum(post_id)}, .{
+                .{ "type=\"submit\" value=\"&#x2B06; {}\"", .{p.upvotes.len} },
+            });
+        }
+        if (login != null and try p.downvotes.has(txn, login.?.user_id)) {
+            try html_form(res, "/undownvote/{}", .{@intFromEnum(post_id)}, .{
+                .{ "type=\"submit\" value=\"&#x2B07; {}\"", .{p.downvotes.len} },
+            });
+        } else {
+            try html_form(res, "/downvote/{}", .{@intFromEnum(post_id)}, .{
+                .{ "type=\"submit\" value=\"&#x2B07; {}\"", .{p.downvotes.len} },
+            });
+        }
+        try res.write(
+            \\<span>&#x1F4AD; {}</span>
+            \\</div>
+        , .{p.comments.len});
+    }
+}

 // }}}
 
 // }}}
 

-fn list_users(env: *lmdb.Env) !void {
+fn list_users(env: lmdb.Env) !void {

     const txn = try env.txn();
     defer txn.abort();
 
     // const users = try Db.users(&txn);
     const txn = try env.txn();
     defer txn.abort();
 
     // const users = try Db.users(&txn);

-    const users = try txn.dbi("users", Id, User);
+    const users = try txn.dbi("users", UserId, User);

     var cursor = try users.cursor();
 
     var cursor = try users.cursor();
 

-    var key: Id = undefined;
+    var key: UserId = undefined;

     var user_maybe = cursor.get(&key, .First);
 
     while (user_maybe) |*user| {
     var user_maybe = cursor.get(&key, .First);
 
     while (user_maybe) |*user| {


@@ -200,7 +527,7 @@ fn list_users(env: *lmdb.Env) !void {
         user_maybe = cursor.get(&key, .Next);
     }
 }
         user_maybe = cursor.get(&key, .Next);
     }
 }

-fn list_user_ids(env: *lmdb.Env) !void {
+fn list_user_ids(env: lmdb.Env) !void {

     const txn = try env.txn();
     defer txn.abort();
 
     const txn = try env.txn();
     defer txn.abort();
 


@@ -217,7 +544,7 @@ fn list_user_ids(env: *lmdb.Env) !void {
     }
 }
 
     }
 }
 

-fn list_sessions(env: *lmdb.Env) !void {
+fn list_sessions(env: lmdb.Env) !void {

     const txn = try env.txn();
     defer txn.abort();
 
     const txn = try env.txn();
     defer txn.abort();
 


@@ -234,9 +561,26 @@ fn list_sessions(env: *lmdb.Env) !void {
     }
 }
 
     }
 }
 

+fn list_posts(env: lmdb.Env) !void {
+    const txn = try env.txn();
+    defer txn.abort();
+
+    const posts = try Db.posts(&txn);
+    var cursor = try posts.cursor();
+
+    var key: PostId = undefined;
+    var post_maybe = cursor.get(&key, .First);
+
+    while (post_maybe) |p| {
+        std.debug.print("[{}] {s}\n", .{ key, p.text.constSlice() });
+
+        post_maybe = cursor.get(&key, .Next);
+    }
+}
+

 const ReqBufferSize = 4096;
 const ReqBufferSize = 4096;

-const ResHeadBufferSize = 4096;
-const ResBodyBufferSize = 4096;
+const ResHeadBufferSize = 1024 * 16;
+const ResBodyBufferSize = 1024 * 16;

 
 pub fn main() !void {
     // server
 
 pub fn main() !void {
     // server


@@ -244,15 +588,17 @@ pub fn main() !void {
     defer server.deinit();
 
     // lmdb
     defer server.deinit();
 
     // lmdb

-    var env = lmdb.Env.open("db", 1024 * 100);
+    var env = try lmdb.Env.open("db", 1024 * 1024 * 10);

     defer env.close();
 
     std.debug.print("Users:\n", .{});
     defer env.close();
 
     std.debug.print("Users:\n", .{});

-    try list_users(&env);
+    try list_users(env);

     std.debug.print("User IDs:\n", .{});
     std.debug.print("User IDs:\n", .{});

-    try list_user_ids(&env);
+    try list_user_ids(env);

     std.debug.print("Sessions:\n", .{});
     std.debug.print("Sessions:\n", .{});

-    try list_sessions(&env);
+    try list_sessions(env);
+    std.debug.print("Posts:\n", .{});
+    try list_posts(env);

 
     try handle_connection(&server, &env);
     // const ThreadCount = 1;
 
     try handle_connection(&server, &env);
     // const ThreadCount = 1;


@@ -284,19 +630,21 @@ fn handle_connection(server: *http.Server, env: *lmdb.Env) !void {
             var res = http.Response.init(req.fd, &res_head_buffer, &res_body_buffer);
 
             // check session token
             var res = http.Response.init(req.fd, &res_head_buffer, &res_body_buffer);
 
             // check session token

-            var logged_in: ?struct {
-                user: User,
-                session_token: SessionToken,
-            } = null;
+            var logged_in: ?Login = null;

 
             if (req.get_cookie("session_token")) |session_token_str| {
                 var session_token: SessionToken = undefined;
                 std.mem.copyForwards(u8, &session_token, session_token_str);
                 // const session_token = try std.fmt.parseUnsigned(SessionToken, session_token_str, 10);
                 // const session_token = std.mem.bytesToValue(SessionToken, session_token_str);
 
             if (req.get_cookie("session_token")) |session_token_str| {
                 var session_token: SessionToken = undefined;
                 std.mem.copyForwards(u8, &session_token, session_token_str);
                 // const session_token = try std.fmt.parseUnsigned(SessionToken, session_token_str, 10);
                 // const session_token = std.mem.bytesToValue(SessionToken, session_token_str);

-                if (get_session_user(env, session_token)) |user| {
+                if (get_session_user_id(env, session_token)) |user_id| {
+                    const txn = try env.txn();
+                    defer txn.abort();
+                    const users = try Db.users(&txn);
+

                     logged_in = .{
                     logged_in = .{

-                        .user = user,
+                        .user = users.get(user_id) orelse return error.UserNotFound,
+                        .user_id = user_id,

                         .session_token = session_token,
                     };
                 } else |err| {
                         .session_token = session_token,
                     };
                 } else |err| {


@@ -311,6 +659,8 @@ fn handle_connection(server: *http.Server, env: *lmdb.Env) !void {
 
             // html
             if (req.method == .GET) {
 
             // html
             if (req.method == .GET) {

+                try write_header(&res, logged_in);
+

                 if (std.mem.eql(u8, req.target, "/register")) {
                     try res.write(
                         \\<form action="/register" method="post">
                 if (std.mem.eql(u8, req.target, "/register")) {
                     try res.write(
                         \\<form action="/register" method="post">


@@ -329,20 +679,35 @@ fn handle_connection(server: *http.Server, env: *lmdb.Env) !void {
                         \\</form>
                     , .{});
                     try res.send();
                         \\</form>
                     , .{});
                     try res.send();

+                } else if (std.mem.startsWith(u8, req.target, "/user/")) {
+                    const username = req.target[6..req.target.len];
+
+                    const txn = try env.txn();
+                    defer txn.abort();
+
+                    const user_ids = try Db.user_ids(&txn);
+                    if (user_ids.get(try Username.fromSlice(username))) |user_id| {
+                        const users = try Db.users(&txn);
+                        const user = users.get(user_id).?;
+                        try write_posts(&res, &txn, user, logged_in);
+                    } else {
+                        try res.write(
+                            \\<p>User not found</pvo>
+                        , .{});
+                    }
+                    try res.send();

                 } else {
                     if (logged_in) |login| {
                 } else {
                     if (logged_in) |login| {

-                        try res.write(
-                            \\<a href="/user/{s}">Home</a>
-                            \\<form action="/logout" method="post"><input type="submit" value="Logout" /></form>
-                            \\<form action="/quit" method="post"><input type="submit" value="Quit" /></form>
-                        , .{login.user.username.constSlice()});
+                        const user = (try get_user(env, login.user_id)).?;
+
+                        const txn = try env.txn();
+                        defer txn.abort();
+
+                        try write_posts(&res, &txn, user, logged_in);
+

                         try res.send();
                     } else {
                         try res.send();
                     } else {

-                        try res.write(
-                            \\<a href="/register">Register</a>
-                            \\<a href="/login">Login</a>
-                            \\<form action="/quit" method="post"><input type="submit" value="Quit" /></form>
-                        , .{});
+                        try res.write("[GET] {s}", .{req.target});

                         try res.send();
                     }
                 }
                         try res.send();
                     }
                 }


@@ -393,6 +758,14 @@ fn handle_connection(server: *http.Server, env: *lmdb.Env) !void {
                             .{"session_token=deleted; Expires=Thu, 01 Jan 1970 00:00:00 GMT"},
                         );
 
                             .{"session_token=deleted; Expires=Thu, 01 Jan 1970 00:00:00 GMT"},
                         );
 

+                        try res.redirect("/");
+                        try res.send();
+                    }
+                } else if (std.mem.eql(u8, req.target, "/post")) {
+                    if (logged_in) |login| {
+                        const text = req.get_value("text").?;
+                        try post(env, login.user_id, text);
+

                         try res.redirect("/");
                         try res.send();
                     }
                         try res.redirect("/");
                         try res.send();
                     }


@@ -400,11 +773,61 @@ fn handle_connection(server: *http.Server, env: *lmdb.Env) !void {
                     try res.redirect("/");
                     try res.send();
                     break :accept;
                     try res.redirect("/");
                     try res.send();
                     break :accept;

+                } else if (std.mem.startsWith(u8, req.target, "/upvote/")) {
+                    const login = logged_in orelse return error.NotLoggedIn;
+
+                    const post_id_str = req.target[8..req.target.len];
+                    const post_id: PostId = @enumFromInt(try std.fmt.parseUnsigned(u64, post_id_str, 10));
+
+                    try vote(env, post_id, login.user_id, .Up);
+                    try unvote(env, post_id, login.user_id, .Down);
+
+                    if (req.get_header("Referer")) |ref| {
+                        try res.redirect(ref);
+                    }
+                    try res.send();
+                } else if (std.mem.startsWith(u8, req.target, "/downvote/")) {
+                    const login = logged_in orelse return error.NotLoggedIn;
+
+                    const post_id_str = req.target[10..req.target.len];
+                    const post_id: PostId = @enumFromInt(try std.fmt.parseUnsigned(u64, post_id_str, 10));
+
+                    try vote(env, post_id, login.user_id, .Down);
+                    try unvote(env, post_id, login.user_id, .Up);
+
+                    if (req.get_header("Referer")) |ref| {
+                        try res.redirect(ref);
+                    }
+                    try res.send();
+                } else if (std.mem.startsWith(u8, req.target, "/unupvote/")) {
+                    const login = logged_in orelse return error.NotLoggedIn;
+
+                    const post_id_str = req.target[10..req.target.len];
+                    const post_id: PostId = @enumFromInt(try std.fmt.parseUnsigned(u64, post_id_str, 10));
+
+                    try unvote(env, post_id, login.user_id, .Up);
+
+                    if (req.get_header("Referer")) |ref| {
+                        try res.redirect(ref);
+                    }
+                    try res.send();
+                } else if (std.mem.startsWith(u8, req.target, "/undownvote/")) {
+                    const login = logged_in orelse return error.NotLoggedIn;
+
+                    const post_id_str = req.target[12..req.target.len];
+                    const post_id: PostId = @enumFromInt(try std.fmt.parseUnsigned(u64, post_id_str, 10));
+
+                    try unvote(env, post_id, login.user_id, .Down);
+
+                    if (req.get_header("Referer")) |ref| {
+                        try res.redirect(ref);
+                    }
+                    try res.send();

                 } else {
                     // try req.respond(
                     //     \\<p>POST</p>
                     // , .{});
                 } else {
                     // try req.respond(
                     //     \\<p>POST</p>
                     // , .{});

-                    try res.write("<p>{s}</p>", .{req.target});
+                    try res.write("<p>[POST] {s}</p>", .{req.target});

                     try res.send();
                 }
             }
                     try res.send();
                 }
             }