reduce boilerplate in main-lib

src/interface.zig

@@ -26,8 +26,8 @@ pub const Request = extern struct {
     headers_len: usize,
 };
 
-pub fn toHeaders(allocator: std.mem.Allocator, headers: std.StringHashMap([]const u8)) ![*]Header {
-    var header_array = try std.ArrayList(Header).initCapacity(allocator, headers.count());
+pub fn toHeaders(alloc: std.mem.Allocator, headers: std.StringHashMap([]const u8)) ![*]Header {
+    var header_array = try std.ArrayList(Header).initCapacity(alloc, headers.count());
     var iterator = headers.iterator();
     while (iterator.next()) |kv| {
         header_array.appendAssumeCapacity(.{
@@ -40,3 +40,59 @@ pub fn toHeaders(allocator: std.mem.Allocator, headers: std.StringHashMap([]cons
     }
     return header_array.items.ptr;
 }
+
+var allocator: ?*std.mem.Allocator = null;
+
+pub const ZigResponse = struct {
+    body: *std.ArrayList(u8),
+    headers: *std.StringHashMap([]const u8),
+};
+
+/// This function is optional and can be exported by zig libraries for
+/// initialization. If exported, it will be called once in the beginning of
+/// a request and will be provided a pointer to std.mem.Allocator, which is
+/// useful for reusing the parent allocator
+pub fn zigInit(parent_allocator: *anyopaque) callconv(.C) void {
+    allocator = @ptrCast(*std.mem.Allocator, @alignCast(@alignOf(*std.mem.Allocator), parent_allocator));
+}
+
+pub const ZigRequestHandler = *const fn (std.mem.Allocator, Request, ZigResponse) anyerror!void;
+
+const log = std.log.scoped(.interface);
+pub fn handleRequest(request: *Request, zigRequestHandler: ZigRequestHandler) ?*Response {
+    // TODO: implement another library in C or Rust or something to show
+    // that anything using a C ABI can be successful
+    var alloc = if (allocator) |a| a.* else @panic("zigInit not called prior to handle_request. This is a coding error");
+
+    // setup response body
+    var response = std.ArrayList(u8).init(alloc);
+
+    // setup headers
+    var headers = std.StringHashMap([]const u8).init(alloc);
+    zigRequestHandler(alloc, request.*, .{
+        .body = &response,
+        .headers = &headers,
+    }) catch |e| {
+        log.err("Unexpected error processing request: {any}", .{e});
+        if (@errorReturnTrace()) |trace| {
+            std.debug.dumpStackTrace(trace.*);
+        }
+        return null;
+    };
+
+    log.debug("response ptr: {*}", .{response.items.ptr});
+    // Marshall data back for handling by server
+
+    var rc = alloc.create(Response) catch @panic("OOM");
+    rc.ptr = response.items.ptr;
+    rc.len = response.items.len;
+    rc.headers = toHeaders(alloc, 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();
+    return rc;
+}

src/main-lib.zig

@@ -4,61 +4,20 @@ const testing = std.testing;
 
 const log = std.log.scoped(.@"main-lib");
 
-var allocator: ?*std.mem.Allocator = null;
-const Response = struct {
-    body: *std.ArrayList(u8),
-    headers: *std.StringHashMap([]const u8),
-};
-
-/// This function is optional and can be exported by zig libraries for
-/// initialization. If exported, it will be called once in the beginning of
-/// a request and will be provided a pointer to std.mem.Allocator, which is
-/// useful for reusing the parent allocator
-export fn zigInit(parent_allocator: *anyopaque) void {
-    allocator = @ptrCast(*std.mem.Allocator, @alignCast(@alignOf(*std.mem.Allocator), parent_allocator));
-}
-export fn handle_request() ?*interface.Response {
-    // TODO: implement another library in C or Rust or something to show
-    // that anything using a C ABI can be successful
-    var alloc = if (allocator) |a| a.* else @panic("zigInit not called prior to handle_request. This is a coding error");
-
-    // setup response body
-    var response = std.ArrayList(u8).init(alloc);
-
-    // setup headers
-    var headers = std.StringHashMap([]const u8).init(alloc);
-    handleRequest(.{
-        .body = &response,
-        .headers = &headers,
-    }) catch |e| {
-        log.err("Unexpected error processing request: {any}", .{e});
-        if (@errorReturnTrace()) |trace| {
-            std.debug.dumpStackTrace(trace.*);
-        }
-        return null;
-    };
-
-    log.debug("response ptr: {*}", .{response.items.ptr});
-    // Marshall data back for handling by server
-
-    var rc = alloc.create(interface.Response) catch @panic("OOM");
-    rc.ptr = response.items.ptr;
-    rc.len = response.items.len;
-    rc.headers = interface.toHeaders(alloc, 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();
-    return rc;
-}
-
-/// request_deinit is an optional export and will be called a the end of the
-/// request. Useful for deallocating memory
+// request_deinit is an optional export and will be called a the end of the
+// request. Useful for deallocating memory
 // export fn request_deinit() void {
 // }
+export fn handle_request(request: *interface.Request) callconv(.C) ?*interface.Response {
+    return interface.handleRequest(request, handleRequest);
+}
+
+comptime {
+    @export(
+        interface.zigInit,
+        .{ .name = "zigInit", .linkage = .Strong },
+    );
+}
 
 // ************************************************************************
 // Boilerplate ^^, Custom code vv
@@ -66,11 +25,12 @@ export fn handle_request() ?*interface.Response {
 //
 // handleRequest function here is the last line of boilerplate and the
 // entry to a request
-fn handleRequest(response: Response) !void {
+fn handleRequest(allocator: std.mem.Allocator, request: interface.Request, response: interface.ZigResponse) !void {
+    _ = allocator;
     // setup
     var response_writer = response.body.writer();
     // real work
-    response_writer.print(" 2.", .{}) catch unreachable;
+    response_writer.print(" {d}", .{request.headers_len}) catch unreachable;
     try response.headers.put("X-custom-foo", "bar");
     log.info("handlerequest header count {d}", .{response.headers.count()});
 }
@@ -79,9 +39,23 @@ test "handle_request" {
     var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
     defer arena.deinit();
     var aa = arena.allocator();
-    allocator = &aa;
-    const response = handle_request().?;
-    try testing.expectEqualStrings(" 2.", response.ptr[0..response.len]);
+    interface.zigInit(&aa);
+    var headers: []interface.Header = @constCast(&[_]interface.Header{.{
+        .name_ptr = @ptrCast([*:0]u8, @constCast("GET".ptr)),
+        .name_len = 3,
+        .value_ptr = @ptrCast([*:0]u8, @constCast("GET".ptr)),
+        .value_len = 3,
+    }});
+    var req = interface.Request{
+        .method = @ptrCast([*:0]u8, @constCast("GET".ptr)),
+        .method_len = 3,
+        .content = @ptrCast([*:0]u8, @constCast("GET".ptr)),
+        .content_len = 3,
+        .headers = headers.ptr,
+        .headers_len = 1,
+    };
+    const response = handle_request(&req).?;
+    try testing.expectEqualStrings(" 1", response.ptr[0..response.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]);
 }

src/main.zig

@@ -477,6 +477,6 @@ test "root path get" {
     std.testing.log_level = .debug;
     log.debug("", .{});
     try testGet("/");
-    try std.testing.expectEqual(@as(usize, 3), test_resp_buf_len);
-    try std.testing.expectEqualStrings(" 2.", test_resp_buf[0..test_resp_buf_len]);
+    try std.testing.expectEqual(@as(usize, 2), test_resp_buf_len);
+    try std.testing.expectEqualStrings(" 1", test_resp_buf[0..test_resp_buf_len]);
 }