Implement MIME type inference

When serving content from `public/`, use MIME type lookup to provide an
appropriate content-type header.

MIME types borrowed from:

  https://mimetype.io/all-types
  https://github.com/patrickmccallum/mimetype-io/blob/master/src/mimeData.json

README.md

@@ -32,10 +32,11 @@ If you are interested in _Jetzig_ you will probably find these tools interesting
 * :white_check_mark: Request/response headers.
 * :white_check_mark: Stack trace output on error.
 * :white_check_mark: Static content generation.
-* :x: Param/JSON payload parsing/abstracting.
+* :white_check_mark: Param/JSON payload parsing/abstracting.
-* :x: Static content paramater definitions.
+* :white_check_mark: Static content parameter definitions.
+* :white_check_mark: Middleware interface.
+* :white_check_mark: MIME type inference.
 * :x: Environment configurations (develompent/production/etc.)
-* :x: Middleware extensions (for e.g. authentication).
 * :x: Email delivery.
 * :x: Custom/non-conventional routes.
 * :x: General-purpose cache.

build.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 
 pub const GenerateRoutes = @import("src/GenerateRoutes.zig");
+pub const GenerateMimeTypes = @import("src/GenerateMimeTypes.zig");
 pub const TemplateFn = @import("src/jetzig.zig").TemplateFn;
 pub const StaticRequest = @import("src/jetzig.zig").StaticRequest;
 pub const http = @import("src/jetzig/http.zig");
@@ -20,9 +21,12 @@ pub fn build(b: *std.Build) !void {
         .optimize = optimize,
     });
 
+    const mime_module = try GenerateMimeTypes.generateMimeModule(b);
+
     b.installArtifact(lib);
 
     const jetzig_module = b.addModule("jetzig", .{ .root_source_file = .{ .path = "src/jetzig.zig" } });
+    jetzig_module.addImport("mime_types", mime_module);
     lib.root_module.addImport("jetzig", jetzig_module);
 
     const zmpl_dep = b.dependency(

build.zig.zon

@@ -3,8 +3,8 @@
     .version = "0.0.0",
     .dependencies = .{
         .zmpl = .{
-            .url = "https://github.com/jetzig-framework/zmpl/archive/41ac97a026e124f93d316eb838fa015a5a52bb15.tar.gz",
+            .url = "https://github.com/jetzig-framework/zmpl/archive/84a712349e0cf679fc5c9900b805335d51d9ce86.tar.gz",
-            .hash = "122053b4c76247572201afbbec8fbde8c014c25984a3ca780ed4f6d514cc939038df",
+            .hash = "1220e9f2133f6cd24c370850cbe3816e3d8b97c33dd822bf7eaf8f6f0ea2cfd2f8db",
         },
     },
 

src/GenerateMimeTypes.zig

@@ -0,0 +1,47 @@
+const std = @import("std");
+
+const JsonMimeType = struct {
+    name: []const u8,
+    fileTypes: [][]const u8,
+};
+
+/// Invoked at build time to parse mimeData.json into an array of `MimeType` which can then be
+/// written out as a Zig struct and imported at runtime.
+pub fn generateMimeModule(build: *std.Build) !*std.Build.Module {
+    const file = try std.fs.openFileAbsolute(build.pathFromRoot("src/jetzig/http/mime/mimeData.json"), .{});
+    const stat = try file.stat();
+    const json = try file.readToEndAlloc(build.allocator, stat.size);
+    defer build.allocator.free(json);
+
+    const parsed_mime_types = try std.json.parseFromSlice(
+        []JsonMimeType,
+        build.allocator,
+        json,
+        .{ .ignore_unknown_fields = true },
+    );
+
+    var buf = std.ArrayList(u8).init(build.allocator);
+    defer buf.deinit();
+
+    const writer = buf.writer();
+
+    try writer.writeAll("pub const MimeType = struct { name: []const u8, file_type: []const u8 };");
+    try writer.writeAll("pub const mime_types = [_]MimeType{\n");
+    for (parsed_mime_types.value) |mime_type| {
+        for (mime_type.fileTypes) |file_type| {
+            const entry = try std.fmt.allocPrint(
+                build.allocator,
+                \\.{{ .name = "{s}", .file_type = "{s}" }},
+                \\
+            ,
+                .{ mime_type.name, file_type },
+            );
+            try writer.writeAll(entry);
+        }
+    }
+    try writer.writeAll("};\n");
+
+    const write_files = build.addWriteFiles();
+    const generated_file = write_files.add("mime_types.zig", buf.items);
+    return build.createModule(.{ .root_source_file = generated_file });
+}

src/jetzig.zig

@@ -33,6 +33,7 @@ pub const View = views.View;
 pub const config = struct {
     pub const max_bytes_request_body: usize = std.math.pow(usize, 2, 16);
     pub const max_bytes_static_content: usize = std.math.pow(usize, 2, 16);
+    pub const public_content = .{ .path = "public" };
 };
 
 pub fn init(allocator: std.mem.Allocator) !App {

src/jetzig/App.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 
 const jetzig = @import("../jetzig.zig");
+const mime_types = @import("mime_types").mime_types; // Generated at build time.
 
 const Self = @This();
 
@@ -18,6 +19,10 @@ pub fn deinit(self: Self) void {
 /// automatically created at build time. `templates` should be
 /// `@import("src/app/views/zmpl.manifest.zig").templates`, created by Zmpl at compile time.
 pub fn start(self: Self, routes: []jetzig.views.Route, templates: []jetzig.TemplateFn) !void {
+    var mime_map = jetzig.http.mime.MimeMap.init(self.allocator);
+    defer mime_map.deinit();
+    try mime_map.build();
+
     var server = jetzig.http.Server.init(
         self.allocator,
         self.host,
@@ -25,6 +30,7 @@ pub fn start(self: Self, routes: []jetzig.views.Route, templates: []jetzig.Templ
         self.server_options,
         routes,
         templates,
+        &mime_map,
     );
 
     for (routes) |*route| {

src/jetzig/http.zig

@@ -10,3 +10,4 @@ pub const Headers = @import("http/Headers.zig");
 pub const Query = @import("http/Query.zig");
 pub const status_codes = @import("http/status_codes.zig");
 pub const middleware = @import("http/middleware.zig");
+pub const mime = @import("http/mime.zig");

src/jetzig/http/Server.zig

@@ -26,6 +26,7 @@ options: ServerOptions,
 start_time: i128 = undefined,
 routes: []jetzig.views.Route,
 templates: []jetzig.TemplateFn,
+mime_map: *jetzig.http.mime.MimeMap,
 
 const Self = @This();
 
@@ -36,6 +37,7 @@ pub fn init(
     options: ServerOptions,
     routes: []jetzig.views.Route,
     templates: []jetzig.TemplateFn,
+    mime_map: *jetzig.http.mime.MimeMap,
 ) Self {
     const server = std.http.Server.init(.{ .reuse_address = true });
 
@@ -49,6 +51,7 @@ pub fn init(
         .options = options,
         .routes = routes,
         .templates = templates,
+        .mime_map = mime_map,
     };
 }
 
@@ -329,8 +332,8 @@ fn matchRoute(self: *Self, request: *jetzig.http.Request, static: bool) !?jetzig
 const StaticResource = struct { content: []const u8, mime_type: []const u8 = "application/octet-stream" };
 
 fn matchStaticResource(self: *Self, request: *jetzig.http.Request) !?StaticResource {
-    const public_content = try matchPublicContent(request);
+    const public_resource = try self.matchPublicContent(request);
-    if (public_content) |content| return .{ .content = content };
+    if (public_resource) |resource| return resource;
 
     const static_content = try self.matchStaticContent(request);
     if (static_content) |content| return .{
@@ -344,11 +347,14 @@ fn matchStaticResource(self: *Self, request: *jetzig.http.Request) !?StaticResou
     return null;
 }
 
-fn matchPublicContent(request: *jetzig.http.Request) !?[]const u8 {
+fn matchPublicContent(self: *Self, request: *jetzig.http.Request) !?StaticResource {
     if (request.path.len < 2) return null;
     if (request.method != .GET) return null;
 
-    var iterable_dir = std.fs.cwd().openDir("public", .{ .iterate = true }) catch |err| {
+    var iterable_dir = std.fs.cwd().openDir(
+        jetzig.config.public_content.path,
+        .{ .iterate = true, .no_follow = true },
+    ) catch |err| {
         switch (err) {
             error.FileNotFound => return null,
             else => return err,
@@ -363,11 +369,17 @@ fn matchPublicContent(request: *jetzig.http.Request) !?[]const u8 {
         if (file.kind != .file) continue;
 
         if (std.mem.eql(u8, file.path, request.path[1..])) {
-            return try iterable_dir.readFileAlloc(
+            const content = try iterable_dir.readFileAlloc(
                 request.allocator,
                 file.path,
                 jetzig.config.max_bytes_static_content,
             );
+            const extension = std.fs.path.extension(file.path);
+            const mime_type = if (self.mime_map.get(extension)) |mime| mime else "application/octet-stream";
+            return .{
+                .content = content,
+                .mime_type = mime_type,
+            };
         }
     }
 

src/jetzig/http/mime.zig

@@ -0,0 +1,54 @@
+// Mime types borrowed from here:
+// https://mimetype.io/all-types
+// https://github.com/patrickmccallum/mimetype-io/blob/master/src/mimeData.json
+
+const std = @import("std");
+
+const mime_types = @import("mime_types").mime_types; // Generated at build time.
+
+/// Provides information about a given MIME Type.
+pub const MimeType = struct {
+    name: []const u8,
+};
+
+/// Attempts to map a given extension to a mime type.
+pub fn fromExtension(extension: []const u8) ?MimeType {
+    for (mime_types) |mime_type| {
+        if (std.mem.eql(u8, extension, mime_type.file_type)) return .{ .name = mime_type.name };
+    }
+    return null;
+}
+
+pub const MimeMap = struct {
+    allocator: std.mem.Allocator,
+    map: std.StringHashMap([]const u8),
+
+    pub fn init(allocator: std.mem.Allocator) MimeMap {
+        return .{
+            .allocator = allocator,
+            .map = std.StringHashMap([]const u8).init(allocator),
+        };
+    }
+
+    pub fn deinit(self: *MimeMap) void {
+        var it = self.map.iterator();
+        while (it.next()) |item| {
+            self.allocator.free(item.key_ptr.*);
+            self.allocator.free(item.value_ptr.*);
+        }
+        self.map.deinit();
+    }
+
+    pub fn build(self: *MimeMap) !void {
+        for (mime_types) |mime_type| {
+            try self.map.put(
+                try self.allocator.dupe(u8, mime_type.file_type),
+                try self.allocator.dupe(u8, mime_type.name),
+            );
+        }
+    }
+
+    pub fn get(self: *MimeMap, file_type: []const u8) ?[]const u8 {
+        return self.map.get(file_type);
+    }
+};