Start work on middleware api

This commit is contained in:
jaina heartles 2022-11-23 20:51:30 -08:00
parent f457b7a0d6
commit 73f7022d36
4 changed files with 391 additions and 11 deletions

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@ -15,6 +15,8 @@ pub const Response = server.Response;
pub const Handler = server.Handler;
pub const Server = server.Server;
pub const middleware = @import("./middleware.zig");
pub const Fields = @import("./headers.zig").Fields;
pub const Protocol = enum {

345
src/http/middleware.zig Normal file
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@ -0,0 +1,345 @@
const std = @import("std");
const root = @import("root");
const builtin = @import("builtin");
const http = @import("./lib.zig");
const util = @import("util");
//const query_utils = @import("./query.zig");
//const json_utils = @import("./json.zig");
const json_utils = util;
const query_utils = util;
fn AddFields(comptime lhs: type, comptime rhs: type) type {
const Ctx = @Type(.{ .Struct = .{
.layout = .Auto,
.fields = std.meta.fields(lhs) ++ std.meta.fields(rhs),
.decls = &.{},
.is_tuple = false,
} });
return Ctx;
}
fn addFields(lhs: anytype, rhs: anytype) AddFields(@TypeOf(lhs), @TypeOf(rhs)) {
var result: AddFields(@TypeOf(lhs), @TypeOf(rhs)) = undefined;
inline for (comptime std.meta.fieldNames(@TypeOf(lhs))) |f| @field(result, f) = @field(lhs, f);
inline for (comptime std.meta.fieldNames(@TypeOf(rhs))) |f| @field(result, f) = @field(rhs, f);
return result;
}
test {
// apply is a plumbing function that applies a tuple of middlewares in order
const base = apply(.{
split_uri,
mount("/abc"),
});
const request = .{ .uri = "/abc/defg/hijkl?some_query=true#section" };
const response = .{};
const initial_context = .{};
try base.handle(request, response, initial_context, {});
}
fn ApplyInternal(comptime fields: []const std.builtin.Type.StructField) type {
if (fields.len == 0) return void;
return NextHandler(
fields[0].field_type,
ApplyInternal(fields[1..]),
);
}
fn applyInternal(middlewares: anytype, comptime fields: []const std.builtin.Type.StructField) ApplyInternal(fields) {
if (fields.len == 0) return {};
return .{
.first = @field(middlewares, fields[0].name),
.next = applyInternal(middlewares, fields[1..]),
};
}
pub fn apply(middlewares: anytype) ApplyInternal(std.meta.fields(@TypeOf(middlewares))) {
return applyInternal(middlewares, std.meta.fields(@TypeOf(middlewares)));
}
pub fn AddContext(comptime Rhs: type) type {
return struct {
values: Rhs,
pub fn handle(self: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
return next.handle(req, res, addFields(ctx, self.values), {});
}
};
}
pub fn NextHandler(comptime First: type, comptime Next: type) type {
return struct {
first: First,
next: Next,
pub fn handle(
self: @This(),
req: anytype,
res: anytype,
ctx: anytype,
next: void,
) !void {
_ = next;
return self.first.handle(req, res, ctx, self.next);
}
};
}
pub fn CatchErrors(comptime ErrorHandler: type) type {
return struct {
error_handler: ErrorHandler,
pub fn handle(self: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
return next.handle(req, res, ctx, {}) catch |err| {
return self.error_handler.handle(
req,
res,
addFields(ctx, .{ .err = err }),
next,
);
};
}
};
}
pub fn catchErrors(error_handler: anytype) CatchErrors(@TypeOf(error_handler)) {
return .{ .error_handler = error_handler };
}
pub const default_error_handler = struct {
fn handle(_: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
_ = next;
std.log.err("Error {} on uri {s}", .{ ctx.err, req.uri });
if (!res.was_opened) {
if (res.open(.internal_server_error)) |stream| {
defer stream.close();
stream.finish() catch {};
}
}
// Tell the server to close the connection after this request
res.should_close = true;
}
}{};
pub const split_uri = struct {
pub fn handle(_: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
var frag_split = std.mem.split(u8, req.uri, "#");
const without_fragment = frag_split.first();
const fragment = frag_split.rest();
var query_split = std.mem.split(u8, without_fragment, "?");
const path = query_split.first();
const query = query_split.rest();
const added_ctx = .{
.path = path,
.query_string = query,
.fragment_string = fragment,
};
return next.handle(
req,
res,
addFields(ctx, added_ctx),
{},
);
}
}{};
// helper function for doing route analysis
fn routeApplies(comptime R: type, req: anytype) bool {
if (R.method != req.method) return false;
var path_iter = util.PathIter.from(req.path);
comptime var route_iter = util.PathIter.from(R.path);
inline while (comptime route_iter.next()) |route_segment| {
const path_segment = path_iter.next() orelse return false;
if (route_segment.len > 0 and route_segment[0] == ':') {
// Route Argument
} else {
if (!std.ascii.eqlIgnoreCase(route_segment, path_segment)) return false;
}
}
if (path_iter.next() != null) return false;
return true;
}
// routes a request to the correct handler based on declared HTTP method and path
pub fn Router(comptime Routes: []const type) type {
return struct {
routes: std.meta.Tuple(Routes),
pub fn handle(self: @This(), req: anytype, res: anytype, ctx: anytype, next: void) !void {
_ = next;
inline for (self.routes) |r| if (routeApplies(@TypeOf(r), req, ctx)) {
if (r.handle(req, res, ctx, {})) |_| {
// success!
return;
} else |err| switch (err) {
error.RouteMismatch => {},
else => return err,
}
};
return error.RouteMismatch;
}
};
}
pub fn Mount(comptime route: []const u8) type {
return struct {
pub fn handle(_: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
var path_iter = util.PathIter.from(ctx.path);
comptime var route_iter = util.PathIter.from(route);
var path_unused = ctx.path;
inline while (comptime route_iter.next()) |route_segment| {
if (comptime route_segment.len == 0) continue;
const path_segment = path_iter.next() orelse return error.RouteMismatch;
path_unused = path_iter.rest();
if (comptime route_segment[0] == ':') {
@compileLog("Argument segments cannot be mounted");
// Route Argument
} else {
if (!std.ascii.eqlIgnoreCase(route_segment, path_segment)) return error.RouteMismatch;
}
}
var new_ctx = ctx;
new_ctx.path = path_unused;
return next.handle(req, res, new_ctx, {});
}
};
}
pub fn mount(comptime route: []const u8) Mount(route) {
return .{};
}
pub fn HandleNotFound(comptime NotFoundHandler: type) type {
return struct {
not_found: NotFoundHandler,
pub fn handler(self: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
return next.handler(req, res, ctx, {}) catch |err| switch (err) {
error.RouteMismatch => return self.not_found.handler(req, res, ctx, {}),
else => return err,
};
}
};
}
fn parsePathArgs(comptime route: []const u8, comptime Args: type, path: []const u8) !Args {
var args: Args = undefined;
var path_iter = util.PathIter.from(path);
comptime var route_iter = util.PathIter.from(route);
inline while (comptime route_iter.next()) |route_segment| {
const path_segment = path_iter.next() orelse return error.RouteMismatch;
if (route_segment.len > 0 and route_segment[0] == ':') {
// route segment is an argument segment
const A = @TypeOf(@field(args, route_segment[1..]));
@field(args, route_segment[1..]) = try parsePathArg(A, path_segment);
} else {
if (!std.ascii.eqlIgnoreCase(route_segment, path_segment)) return error.RouteMismatch;
}
}
if (path_iter.next() != null) return error.RouteMismatch;
return args;
}
fn parsePathArg(comptime T: type, segment: []const u8) !T {
if (T == []const u8) return segment;
if (comptime std.meta.trait.isContainer(T) and std.meta.trait.hasFn("parse")(T)) return T.parse(segment);
@compileError("Unsupported Type " ++ @typeName(T));
}
pub fn ParsePathArgs(comptime route: []const u8, comptime Args: type) type {
return struct {
pub fn handle(_: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
return next.handle(
req,
res,
addFields(ctx, .{ .args = parsePathArgs(route, Args, req.path) }),
{},
);
}
};
}
const BaseContentType = enum {
json,
url_encoded,
octet_stream,
other,
};
fn parseBody(comptime T: type, content_type: BaseContentType, reader: anytype, alloc: std.mem.Allocator) !T {
const buf = try reader.readAllAlloc(alloc, 1 << 16);
defer alloc.free(buf);
switch (content_type) {
.octet_stream, .json => {
const body = try json_utils.parse(T, buf, alloc);
defer json_utils.parseFree(body, alloc);
return try util.deepClone(alloc, body);
},
.url_encoded => return query_utils.parseQuery(alloc, T, buf) catch |err| switch (err) {
error.NoQuery => error.NoBody,
else => err,
},
else => return error.UnsupportedMediaType,
}
}
fn matchContentType(hdr: ?[]const u8) ?BaseContentType {
if (hdr) |h| {
if (std.ascii.eqlIgnoreCase(h, "application/x-www-form-urlencoded")) return .url_encoded;
if (std.ascii.eqlIgnoreCase(h, "application/json")) return .json;
if (std.ascii.eqlIgnoreCase(h, "application/octet-stream")) return .octet_stream;
return .other;
}
return null;
}
pub fn ParseBody(comptime Body: type) type {
return struct {
pub fn handle(_: @This(), req: anytype, res: anytype, ctx: anytype, next: anytype) !void {
const base_content_type = matchContentType(req.headers.get("Content-Type"));
var stream = req.body orelse return error.NoBody;
const body = try parseBody(Body, base_content_type orelse .json, stream.reader(), ctx.allocator);
defer ctx.allocator.free(body);
return next.handler(
req,
res,
addFields(ctx, .{ .body = body }),
);
}
};
}
pub fn ParseQueryParams(comptime Next: type, comptime QueryParams: type) type {
return struct {
next: Next,
pub fn handler(self: @This(), req: anytype, res: anytype, ctx: anytype) !void {
const query = try query_utils.parseQuery(ctx.allocator, QueryParams, ctx.query_string);
defer ctx.allocator.free(query);
return self.next.handler(
req,
res,
addFields(ctx, .{ .query = query }),
);
}
};
}

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@ -18,14 +18,36 @@ pub const timelines = @import("./controllers/api/timelines.zig");
const web = @import("./controllers/web.zig");
const mdw = http.middleware;
const router = Router(&.{});
const not_found = struct {
pub fn handler(self: @This(), _: anytype, res: anytype, ctx: anytype) !void {
var headers = http.Fields.init(ctx.allocator);
defer headers.deinit();
var stream = try res.open(.not_found, &headers);
defer stream.close();
try stream.finish();
}
};
const base_handler = mdw.SplitUri(mdw.CatchErrors(not_found, mdw.DefaultErrorHandler));
fn ApiCall(comptime Route: type) type {
return mdw.
}
pub fn routeRequest(api_source: anytype, req: *http.Request, res: *http.Response, alloc: std.mem.Allocator) void {
// TODO: hashmaps?
var response = Response{ .headers = http.Fields.init(alloc), .res = res };
defer response.headers.deinit();
base_handler
//var response = Response{ .headers = http.Fields.init(alloc), .res = res };
//defer response.headers.deinit();
const found = routeRequestInternal(api_source, req, &response, alloc);
//const found = routeRequestInternal(api_source, req, &response, alloc);
if (!found) response.status(.not_found) catch {};
//if (!found) response.status(.not_found) catch {};
}
fn routeRequestInternal(api_source: anytype, req: *http.Request, res: *Response, alloc: std.mem.Allocator) bool {

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@ -49,19 +49,30 @@ pub const QueryIter = struct {
pub const PathIter = struct {
is_first: bool,
iter: Separator('/'),
iter: std.mem.SplitIterator(u8),
pub fn from(path: []const u8) PathIter {
return .{ .is_first = true, .iter = Separator('/').from(path) };
return .{ .is_first = true, .iter = std.mem.split(u8, path, "/") };
}
pub fn next(self: *PathIter) ?[]const u8 {
if (self.is_first) {
self.is_first = false;
return self.iter.next() orelse "";
}
defer self.is_first = false;
while (self.iter.next()) |it| if (it.len != 0) {
return it;
};
return self.iter.next();
if (self.is_first) return self.iter.rest();
return null;
}
pub fn first(self: *PathIter) []const u8 {
std.debug.assert(self.is_first);
return self.next().?;
}
pub fn rest(self: *PathIter) []const u8 {
return self.iter.rest();
}
};