allow lib more control in status reporting

src/interface.zig

@@ -14,6 +14,11 @@ pub const Response = extern struct {
 
     headers: [*]Header,
     headers_len: usize,
+
+    status: usize,
+
+    reason_ptr: [*]u8,
+    reason_len: usize,
 };
 
 pub const Request = extern struct {
@@ -39,7 +44,7 @@ pub const ZigRequest = struct {
     target: []const u8,
     method: [:0]u8,
     content: []u8,
-    headers: []Header,
+    headers: std.http.Headers,
 };
 
 pub const ZigHeader = struct {
@@ -48,11 +53,33 @@ pub const ZigHeader = struct {
 };
 
 pub const ZigResponse = struct {
+    status: std.http.Status = .ok,
+    reason: ?[]const u8 = null,
     body: *std.ArrayList(u8),
-    headers: *std.StringHashMap([]const u8),
+    headers: std.http.Headers,
+    request: ZigRequest,
+    prepend: std.ArrayList(u8),
+
+    pub fn write(res: *ZigResponse, bytes: []const u8) !usize {
+        return res.prepend.writer().write(bytes);
+    }
+
+    pub fn writeAll(res: *ZigResponse, bytes: []const u8) !void {
+        return res.prepend.writer().writeAll(bytes);
+    }
+
+    pub fn writer(res: *ZigResponse) std.io.Writer {
+        return res.prepend.writer().writer();
+    }
+
+    pub fn finish(res: *ZigResponse) !void {
+        if (res.prepend.items.len > 0)
+            try res.body.insertSlice(0, res.prepend.items);
+        res.prepend.deinit();
+    }
 };
 
-pub const ZigRequestHandler = *const fn (std.mem.Allocator, ZigRequest, ZigResponse) anyerror!void;
+pub const ZigRequestHandler = *const fn (std.mem.Allocator, *ZigResponse) anyerror!void;
 
 /// This function is optional and can be exported by zig libraries for
 /// initialization. If exported, it will be called once in the beginning of
@@ -64,26 +91,18 @@ pub fn zigInit(parent_allocator: *anyopaque) callconv(.C) void {
     allocator = @ptrCast(@alignCast(parent_allocator));
 }
 
-pub fn toZigHeader(header: Header) ZigHeader {
-    return .{
-        .name = header.name_ptr[0..header.name_len],
-        .value = header.value_ptr[0..header.value_len],
-    };
-}
-
 /// Converts a StringHashMap to the structure necessary for passing through the
 /// C boundary. This will be called automatically for you via the handleRequest function
 /// and is also used by the main processing loop to coerce request headers
-fn toHeaders(alloc: std.mem.Allocator, headers: std.StringHashMap([]const u8)) ![*]Header {
+fn toHeaders(alloc: std.mem.Allocator, headers: std.http.Headers) ![*]Header {
-    var header_array = try std.ArrayList(Header).initCapacity(alloc, headers.count());
+    var header_array = try std.ArrayList(Header).initCapacity(alloc, headers.list.items.len);
-    var iterator = headers.iterator();
+    for (headers.list.items) |*field| {
-    while (iterator.next()) |kv| {
         header_array.appendAssumeCapacity(.{
-            .name_ptr = @constCast(kv.key_ptr.*).ptr,
+            .name_ptr = @constCast(field.name.ptr),
-            .name_len = kv.key_ptr.*.len,
+            .name_len = field.name.len,
 
-            .value_ptr = @constCast(kv.value_ptr.*).ptr,
+            .value_ptr = @constCast(field.value.ptr),
-            .value_len = kv.value_ptr.*.len,
+            .value_len = field.value.len,
         });
     }
     return header_array.items.ptr;
@@ -104,42 +123,73 @@ pub fn handleRequest(request: *Request, zigRequestHandler: ZigRequestHandler) ?*
     var response = std.ArrayList(u8).init(alloc);
 
     // setup headers
-    var headers = std.StringHashMap([]const u8).init(alloc);
+    var request_headers = std.http.Headers.init(alloc);
-    zigRequestHandler(
+    for (0..request.headers_len) |i|
-        alloc,
+        request_headers.append(
-        .{
+            request.headers[i].name_ptr[0..request.headers[i].name_len],
+            request.headers[i].value_ptr[0..request.headers[i].value_len],
+        ) catch |e| {
+            log.err("Unexpected error processing request: {any}", .{e});
+            if (@errorReturnTrace()) |trace| {
+                std.debug.dumpStackTrace(trace.*);
+            }
+            return null;
+        };
+
+    var prepend = std.ArrayList(u8).init(alloc);
+    var zig_response = ZigResponse{
+        .headers = .{ .allocator = alloc },
+        .body = &response,
+        .prepend = prepend,
+        .request = .{
+            .content = request.content[0..request.content_len],
             .target = request.target[0..request.target_len],
             .method = request.method[0..request.method_len :0],
-            .content = request.content[0..request.content_len],
+            .headers = request_headers,
-            .headers = request.headers[0..request.headers_len],
-        },
-        .{
-            .body = &response,
-            .headers = &headers,
         },
+    };
+    zigRequestHandler(
+        alloc,
+        &zig_response,
     ) catch |e| {
         log.err("Unexpected error processing request: {any}", .{e});
         if (@errorReturnTrace()) |trace| {
             std.debug.dumpStackTrace(trace.*);
         }
-        return null;
+        if (zig_response.status == .ok) // this was an unexpected throw
+            zig_response.status = .internal_server_error;
+        return buildResponse(alloc, &zig_response);
     };
 
     // Marshall data back for handling by server
+    return buildResponse(alloc, &zig_response);
+}
 
+fn buildResponse(alloc: std.mem.Allocator, zig_response: *ZigResponse) ?*Response {
     var rc = alloc.create(Response) catch {
         log.err("Could not allocate memory for response object. This may be fatal", .{});
         return null;
     };
-    rc.ptr = response.items.ptr;
+    zig_response.finish() catch {
-    rc.len = response.items.len;
+        log.err("Could not allocate memory for response object. This may be fatal", .{});
-    rc.headers = toHeaders(alloc, headers) catch |e| {
+        return null;
+    };
+
+    rc.ptr = zig_response.body.items.ptr;
+    rc.len = zig_response.body.items.len;
+    rc.headers = toHeaders(alloc, zig_response.headers) catch |e| {
         log.err("Unexpected error processing request: {any}", .{e});
         if (@errorReturnTrace()) |trace| {
             std.debug.dumpStackTrace(trace.*);
         }
         return null;
     };
-    rc.headers_len = headers.count();
+    rc.headers_len = zig_response.headers.list.items.len;
+    rc.status = if (zig_response.status == .ok) 0 else @intFromEnum(zig_response.status);
+    rc.reason_len = 0;
+    if (zig_response.reason) |*r| {
+        rc.reason_ptr = @constCast(r.ptr);
+        rc.reason_len = r.len;
+    }
     return rc;
 }

src/main-lib.zig

@@ -57,27 +57,33 @@ export fn handle_request(request: *interface.Request) callconv(.C) ?*interface.R
 //
 // handleRequest function here is the last line of boilerplate and the
 // entry to a request
-fn handleRequest(allocator: std.mem.Allocator, request: interface.ZigRequest, response: interface.ZigResponse) !void {
+fn handleRequest(allocator: std.mem.Allocator, response: *interface.ZigResponse) !void {
     _ = allocator;
     // setup
     var response_writer = response.body.writer();
     // real work
-    for (request.headers) |h| {
+    if (response.request.headers.getFirstValue("host")) |host| {
-        const header = interface.toZigHeader(h);
+        if (std.mem.startsWith(u8, host, "iam")) {
-        // std.debug.print("\n{s}: {s}\n", .{ header.name, header.value });
-        if (std.ascii.eqlIgnoreCase(header.name, "host") and std.mem.startsWith(u8, header.value, "iam")) {
             try response_writer.print("iam response", .{});
             return;
         }
-        if (std.ascii.eqlIgnoreCase(header.name, "x-slow")) {
-            std.time.sleep(std.time.ns_per_ms * (std.fmt.parseInt(usize, header.value, 10) catch 1000));
-            try response_writer.print("i am slow\n\n", .{});
-            return;
-        }
     }
-    try response_writer.print(" {d}", .{request.headers.len});
+    if (response.request.headers.getFirstValue("x-slow")) |ms| {
-    try response.headers.put("X-custom-foo", "bar");
+        std.time.sleep(std.time.ns_per_ms * (std.fmt.parseInt(usize, ms, 10) catch 1000));
-    log.info("handlerequest header count {d}", .{response.headers.count()});
+        try response_writer.print("i am slow\n\n", .{});
+        return;
+    }
+    if (response.request.headers.getFirstValue("x-log-this")) |l| {
+        try response.writeAll(l);
+    }
+    if (response.request.headers.getFirstValue("x-status")) |s| {
+        response.status = @enumFromInt(std.fmt.parseInt(u10, s, 10) catch 500);
+    }
+    if (response.request.headers.getFirstValue("x-throw")) |_| {
+        return error.Thrown;
+    }
+    try response_writer.print(" {d}", .{response.request.headers.list.items.len});
+    try response.headers.append("X-custom-foo", "bar");
 }
 
 test "handle_request" {
@@ -99,10 +105,104 @@ test "handle_request" {
         .content = @ptrCast(@constCast("GET".ptr)),
         .content_len = 3,
         .headers = headers.ptr,
-        .headers_len = 1,
+        .headers_len = headers.len,
     };
     const response = handle_request(&req).?;
     try testing.expectEqualStrings(" 1", response.ptr[0..response.len]);
+    try testing.expectEqual(@as(usize, 1), response.headers_len);
     try testing.expectEqualStrings("X-custom-foo", response.headers[0].name_ptr[0..response.headers[0].name_len]);
     try testing.expectEqualStrings("bar", response.headers[0].value_ptr[0..response.headers[0].value_len]);
 }
+
+test "lib can write data directly" {
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    var aa = arena.allocator();
+    interface.zigInit(&aa);
+    var headers: []interface.Header = @constCast(&[_]interface.Header{.{
+        .name_ptr = @ptrCast(@constCast("x-log-this".ptr)),
+        .name_len = "x-log-this".len,
+        .value_ptr = @ptrCast(@constCast("I am a teapot".ptr)),
+        .value_len = "I am a teapot".len,
+    }});
+    var req = interface.Request{
+        .target = @ptrCast(@constCast("/".ptr)),
+        .target_len = 1,
+        .method = @ptrCast(@constCast("GET".ptr)),
+        .method_len = 3,
+        .content = @ptrCast(@constCast("GET".ptr)),
+        .content_len = 3,
+        .headers = headers.ptr,
+        .headers_len = headers.len,
+    };
+    const response = handle_request(&req).?;
+    try testing.expectEqual(@as(usize, 1), response.headers_len);
+    try testing.expectEqualStrings("X-custom-foo", response.headers[0].name_ptr[0..response.headers[0].name_len]);
+    try testing.expectEqualStrings("bar", response.headers[0].value_ptr[0..response.headers[0].value_len]);
+    try testing.expectEqualStrings("I am a teapot 1", response.ptr[0..response.len]);
+}
+test "lib can write data directly and still throw" {
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    var aa = arena.allocator();
+    interface.zigInit(&aa);
+    var headers: []interface.Header = @constCast(&[_]interface.Header{ .{
+        .name_ptr = @ptrCast(@constCast("x-log-this".ptr)),
+        .name_len = "x-log-this".len,
+        .value_ptr = @ptrCast(@constCast("I am a teapot".ptr)),
+        .value_len = "I am a teapot".len,
+    }, .{
+        .name_ptr = @ptrCast(@constCast("x-throw".ptr)),
+        .name_len = "x-throw".len,
+        .value_ptr = @ptrCast(@constCast("I am a teapot".ptr)),
+        .value_len = "I am a teapot".len,
+    } });
+    var req = interface.Request{
+        .target = @ptrCast(@constCast("/".ptr)),
+        .target_len = 1,
+        .method = @ptrCast(@constCast("GET".ptr)),
+        .method_len = 3,
+        .content = @ptrCast(@constCast("GET".ptr)),
+        .content_len = 3,
+        .headers = headers.ptr,
+        .headers_len = headers.len,
+    };
+    const response = handle_request(&req).?;
+    try testing.expectEqual(@as(usize, 500), response.status);
+    try testing.expectEqualStrings("I am a teapot", response.ptr[0..response.len]);
+}
+test "lib can set status, update data directly and still throw" {
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    var aa = arena.allocator();
+    interface.zigInit(&aa);
+    var headers: []interface.Header = @constCast(&[_]interface.Header{ .{
+        .name_ptr = @ptrCast(@constCast("x-log-this".ptr)),
+        .name_len = "x-log-this".len,
+        .value_ptr = @ptrCast(@constCast("I am a teapot".ptr)),
+        .value_len = "I am a teapot".len,
+    }, .{
+        .name_ptr = @ptrCast(@constCast("x-throw".ptr)),
+        .name_len = "x-throw".len,
+        .value_ptr = @ptrCast(@constCast("I am a teapot".ptr)),
+        .value_len = "I am a teapot".len,
+    }, .{
+        .name_ptr = @ptrCast(@constCast("x-status".ptr)),
+        .name_len = "x-status".len,
+        .value_ptr = @ptrCast(@constCast("418".ptr)),
+        .value_len = "418".len,
+    } });
+    var req = interface.Request{
+        .target = @ptrCast(@constCast("/".ptr)),
+        .target_len = 1,
+        .method = @ptrCast(@constCast("GET".ptr)),
+        .method_len = 3,
+        .content = @ptrCast(@constCast("GET".ptr)),
+        .content_len = 3,
+        .headers = headers.ptr,
+        .headers_len = headers.len,
+    };
+    const response = handle_request(&req).?;
+    try testing.expectEqual(@as(usize, 418), response.status);
+    try testing.expectEqualStrings("I am a teapot", response.ptr[0..response.len]);
+}

src/main.zig

@@ -100,6 +100,12 @@ fn serve(allocator: *std.mem.Allocator, response: *std.http.Server.Response) !*F
     var slice: []u8 = serve_result.ptr[0..serve_result.len];
     log.debug("response body: {s}", .{slice});
 
+    if (serve_result.status != 0) {
+        response.status = @enumFromInt(serve_result.status);
+        if (serve_result.reason_len > 0) {
+            response.reason = serve_result.reason_ptr[0..serve_result.reason_len];
+        }
+    }
     // Deal with results
     var content_type_added = false;
     for (0..serve_result.headers_len) |inx| {
@@ -619,6 +625,7 @@ test {
     std.testing.refAllDecls(@This());
     std.testing.refAllDecls(config);
     std.testing.refAllDecls(interface);
+    std.testing.refAllDecls(@import("main-lib.zig"));
 }
 var test_resp_buf: [1024]u8 = undefined;
 var test_resp_buf_len: usize = undefined;