Form File support

src/http/multipart.zig

@@ -110,6 +110,11 @@ const MultipartFormField = struct {
     content_type: ?[]const u8 = null,
 };
 
+const FormFile = struct {
+    data: []const u8,
+    filename: []const u8,
+};
+
 pub fn MultipartForm(comptime ReaderType: type) type {
     return struct {
         stream: MultipartStream(ReaderType),
@@ -145,27 +150,49 @@ pub fn openForm(multipart_stream: anytype) MultipartForm(@TypeOf(multipart_strea
     return .{ .stream = multipart_stream };
 }
 
+fn Deserializer(comptime Result: type) type {
+    return util.DeserializerContext(Result, MultipartFormField, struct {
+        pub const options = .{ .isScalar = isScalar, .embed_unions = true };
+
+        pub fn isScalar(comptime T: type) bool {
+            if (T == FormFile or T == ?FormFile) return true;
+            return util.serialize.defaultIsScalar(T);
+        }
+
+        pub fn deserializeScalar(_: @This(), alloc: std.mem.Allocator, comptime T: type, val: MultipartFormField) !T {
+            if (T == FormFile or T == ?FormFile) return try deserializeFormFile(alloc, val);
+
+            if (val.filename != null) return error.FilenameProvidedForNonFile;
+            return try util.serialize.deserializeString(alloc, T, val.value);
+        }
+
+        fn deserializeFormFile(alloc: std.mem.Allocator, val: MultipartFormField) !FormFile {
+            const data = try util.deepClone(alloc, val.value);
+            errdefer util.deepFree(alloc, data);
+            const filename = try util.deepClone(alloc, val.filename orelse "(untitled)");
+            return FormFile{
+                .data = data,
+                .filename = filename,
+            };
+        }
+    });
+}
+
 pub fn parseFormData(comptime T: type, boundary: []const u8, reader: anytype, alloc: std.mem.Allocator) !T {
     var form = openForm(try openMultipart(boundary, reader));
 
-    var ds = util.Deserializer(T){};
+    var ds = Deserializer(T){};
     defer {
         var iter = ds.iterator();
         while (iter.next()) |pair| {
-            alloc.free(pair.value);
+            util.deepFree(alloc, pair.value);
         }
     }
     while (true) {
         var part = (try form.next(alloc)) orelse break;
         errdefer util.deepFree(alloc, part);
 
-        try ds.setSerializedField(part.name, part.value);
-
-        alloc.free(part.name);
-
-        // TODO:
-        if (part.content_type) |v| alloc.free(v);
-        if (part.filename) |v| alloc.free(v);
+        try ds.setSerializedField(part.name, part);
     }
 
     return try ds.finish(alloc);

src/util/serialize.zig

@@ -1,7 +1,7 @@
 const std = @import("std");
 const util = @import("./lib.zig");
 
-const FieldRef = []const []const u8;
+pub const FieldRef = []const []const u8;
 
 pub fn defaultIsScalar(comptime T: type) bool {
     if (comptime std.meta.trait.is(.Optional)(T) and defaultIsScalar(std.meta.Child(T))) return true;