Commit d574875f00

Andrew Kelley <andrew@ziglang.org>
2024-02-17 01:12:03
Revert "std.http: remove 'done' flag"
This reverts commit 42be972a72c86b32ad8403d082ab42763c6facec. Using a bit to distinguish between headers and trailers is fine. It was just named and documented poorly.
1 parent 3d61890
Changed files (4)
lib
test
standalone
lib/std/http/Client.zig
@@ -649,7 +649,7 @@ pub const Request = struct {
     /// Frees all resources associated with the request.
     pub fn deinit(req: *Request) void {
         if (req.connection) |connection| {
-            if (req.response.parser.state != .complete) {
+            if (!req.response.parser.done) {
                 // If the response wasn't fully read, then we need to close the connection.
                 connection.closing = true;
             }
@@ -664,7 +664,7 @@ pub const Request = struct {
     // or keep those which will be used.
     // This needs to be kept in sync with deinit and request.
     fn redirect(req: *Request, uri: Uri) !void {
-        assert(req.response.parser.state == .complete);
+        assert(req.response.parser.done);
 
         req.client.connection_pool.release(req.client.allocator, req.connection.?);
         req.connection = null;
@@ -823,12 +823,12 @@ pub const Request = struct {
     }
 
     fn transferRead(req: *Request, buf: []u8) TransferReadError!usize {
-        if (req.response.parser.state == .complete) return 0;
+        if (req.response.parser.done) return 0;
 
         var index: usize = 0;
         while (index == 0) {
             const amt = try req.response.parser.read(req.connection.?, buf[index..], req.response.skip);
-            if (amt == 0 and req.response.parser.state == .complete) break;
+            if (amt == 0 and req.response.parser.done) break;
             index += amt;
         }
 
@@ -873,7 +873,7 @@ pub const Request = struct {
             if (req.response.status == .@"continue") {
                 // We're done parsing the continue response; reset to prepare
                 // for the real response.
-                req.response.parser.state = .complete;
+                req.response.parser.done = true;
                 req.response.parser.reset();
 
                 if (req.handle_continue)
@@ -885,7 +885,7 @@ pub const Request = struct {
             // we're switching protocols, so this connection is no longer doing http
             if (req.method == .CONNECT and req.response.status.class() == .success) {
                 connection.closing = false;
-                req.response.parser.state = .complete;
+                req.response.parser.done = true;
                 return; // the connection is not HTTP past this point
             }
 
@@ -899,7 +899,7 @@ pub const Request = struct {
             if (req.method == .HEAD or req.response.status.class() == .informational or
                 req.response.status == .no_content or req.response.status == .not_modified)
             {
-                req.response.parser.state = .complete;
+                req.response.parser.done = true;
                 return; // The response is empty; no further setup or redirection is necessary.
             }
 
@@ -914,7 +914,7 @@ pub const Request = struct {
             } else if (req.response.content_length) |cl| {
                 req.response.parser.next_chunk_length = cl;
 
-                if (cl == 0) req.response.parser.state = .complete;
+                if (cl == 0) req.response.parser.done = true;
             } else {
                 // read until the connection is closed
                 req.response.parser.next_chunk_length = std.math.maxInt(u64);
@@ -973,7 +973,7 @@ pub const Request = struct {
                 try req.send(.{});
             } else {
                 req.response.skip = false;
-                if (req.response.parser.state != .complete) {
+                if (!req.response.parser.done) {
                     switch (req.response.transfer_compression) {
                         .identity => req.response.compression = .none,
                         .compress, .@"x-compress" => return error.CompressionUnsupported,
lib/std/http/protocol.zig
@@ -7,76 +7,64 @@ const assert = std.debug.assert;
 const use_vectors = builtin.zig_backend != .stage2_x86_64;
 
 pub const State = enum {
-    /// Begin header parsing states.
     invalid,
+
+    // Begin header and trailer parsing states.
+
     start,
     seen_n,
     seen_r,
     seen_rn,
     seen_rnr,
-    headers_end,
-    /// Begin transfer-encoding: chunked parsing states.
+    finished,
+
+    // Begin transfer-encoding: chunked parsing states.
+
     chunk_head_size,
     chunk_head_ext,
     chunk_head_r,
     chunk_data,
     chunk_data_suffix,
     chunk_data_suffix_r,
-    /// When the parser has finished parsing a complete message. A message is
-    /// only complete after the entire body has been read and any trailing
-    /// headers have been parsed.
-    complete,
 
     /// Returns true if the parser is in a content state (ie. not waiting for more headers).
     pub fn isContent(self: State) bool {
         return switch (self) {
-            .invalid,
-            .start,
-            .seen_n,
-            .seen_r,
-            .seen_rn,
-            .seen_rnr,
-            => false,
-
-            .headers_end,
-            .chunk_head_size,
-            .chunk_head_ext,
-            .chunk_head_r,
-            .chunk_data,
-            .chunk_data_suffix,
-            .chunk_data_suffix_r,
-            .complete,
-            => true,
+            .invalid, .start, .seen_n, .seen_r, .seen_rn, .seen_rnr => false,
+            .finished, .chunk_head_size, .chunk_head_ext, .chunk_head_r, .chunk_data, .chunk_data_suffix, .chunk_data_suffix_r => true,
         };
     }
 };
 
 pub const HeadersParser = struct {
-    state: State,
+    state: State = .start,
     /// A fixed buffer of len `max_header_bytes`.
     /// Pointers into this buffer are not stable until after a message is complete.
     header_bytes_buffer: []u8,
     header_bytes_len: u32,
     next_chunk_length: u64,
+    /// `false`: headers. `true`: trailers.
+    done: bool,
 
     /// Initializes the parser with a provided buffer `buf`.
     pub fn init(buf: []u8) HeadersParser {
         return .{
-            .state = .start,
             .header_bytes_buffer = buf,
             .header_bytes_len = 0,
+            .done = false,
             .next_chunk_length = 0,
         };
     }
 
     /// Reinitialize the parser.
-    /// Asserts the parser is in the `complete` state.
+    /// Asserts the parser is in the "done" state.
     pub fn reset(hp: *HeadersParser) void {
-        assert(hp.state == .complete);
+        assert(hp.done);
         hp.* = .{
             .state = .start,
             .header_bytes_buffer = hp.header_bytes_buffer,
             .header_bytes_len = 0,
+            .done = false,
             .next_chunk_length = 0,
         };
     }
@@ -101,8 +89,7 @@ pub const HeadersParser = struct {
         while (true) {
             switch (r.state) {
                 .invalid => unreachable,
-                .complete => unreachable,
-                .headers_end => return index,
+                .finished => return index,
                 .start => switch (len - index) {
                     0 => return index,
                     1 => {
@@ -126,7 +113,7 @@ pub const HeadersParser = struct {
 
                         switch (b16) {
                             int16("\r\n") => r.state = .seen_rn,
-                            int16("\n\n") => r.state = .headers_end,
+                            int16("\n\n") => r.state = .finished,
                             else => {},
                         }
 
@@ -145,7 +132,7 @@ pub const HeadersParser = struct {
 
                         switch (b16) {
                             int16("\r\n") => r.state = .seen_rn,
-                            int16("\n\n") => r.state = .headers_end,
+                            int16("\n\n") => r.state = .finished,
                             else => {},
                         }
 
@@ -170,7 +157,7 @@ pub const HeadersParser = struct {
 
                         switch (b16) {
                             int16("\r\n") => r.state = .seen_rn,
-                            int16("\n\n") => r.state = .headers_end,
+                            int16("\n\n") => r.state = .finished,
                             else => {},
                         }
 
@@ -180,7 +167,7 @@ pub const HeadersParser = struct {
                         }
 
                         switch (b32) {
-                            int32("\r\n\r\n") => r.state = .headers_end,
+                            int32("\r\n\r\n") => r.state = .finished,
                             else => {},
                         }
 
@@ -228,7 +215,7 @@ pub const HeadersParser = struct {
 
                                 switch (b16) {
                                     int16("\r\n") => r.state = .seen_rn,
-                                    int16("\n\n") => r.state = .headers_end,
+                                    int16("\n\n") => r.state = .finished,
                                     else => {},
                                 }
                             },
@@ -245,7 +232,7 @@ pub const HeadersParser = struct {
 
                                 switch (b16) {
                                     int16("\r\n") => r.state = .seen_rn,
-                                    int16("\n\n") => r.state = .headers_end,
+                                    int16("\n\n") => r.state = .finished,
                                     else => {},
                                 }
 
@@ -262,10 +249,10 @@ pub const HeadersParser = struct {
                                     const b16 = intShift(u16, b32);
 
                                     if (b32 == int32("\r\n\r\n")) {
-                                        r.state = .headers_end;
+                                        r.state = .finished;
                                         return index + i + 4;
                                     } else if (b16 == int16("\n\n")) {
-                                        r.state = .headers_end;
+                                        r.state = .finished;
                                         return index + i + 2;
                                     }
                                 }
@@ -282,7 +269,7 @@ pub const HeadersParser = struct {
 
                                 switch (b16) {
                                     int16("\r\n") => r.state = .seen_rn,
-                                    int16("\n\n") => r.state = .headers_end,
+                                    int16("\n\n") => r.state = .finished,
                                     else => {},
                                 }
 
@@ -302,7 +289,7 @@ pub const HeadersParser = struct {
                     0 => return index,
                     else => {
                         switch (bytes[index]) {
-                            '\n' => r.state = .headers_end,
+                            '\n' => r.state = .finished,
                             else => r.state = .start,
                         }
 
@@ -334,7 +321,7 @@ pub const HeadersParser = struct {
                         switch (b16) {
                             int16("\r\n") => r.state = .seen_rn,
                             int16("\n\r") => r.state = .seen_rnr,
-                            int16("\n\n") => r.state = .headers_end,
+                            int16("\n\n") => r.state = .finished,
                             else => {},
                         }
 
@@ -353,12 +340,12 @@ pub const HeadersParser = struct {
 
                         switch (b16) {
                             int16("\r\n") => r.state = .seen_rn,
-                            int16("\n\n") => r.state = .headers_end,
+                            int16("\n\n") => r.state = .finished,
                             else => {},
                         }
 
                         switch (b24) {
-                            int24("\n\r\n") => r.state = .headers_end,
+                            int24("\n\r\n") => r.state = .finished,
                             else => {},
                         }
 
@@ -388,8 +375,8 @@ pub const HeadersParser = struct {
                         }
 
                         switch (b16) {
-                            int16("\r\n") => r.state = .headers_end,
-                            int16("\n\n") => r.state = .headers_end,
+                            int16("\r\n") => r.state = .finished,
+                            int16("\n\n") => r.state = .finished,
                             else => {},
                         }
 
@@ -401,7 +388,7 @@ pub const HeadersParser = struct {
                     0 => return index,
                     else => {
                         switch (bytes[index]) {
-                            '\n' => r.state = .headers_end,
+                            '\n' => r.state = .finished,
                             else => r.state = .start,
                         }
 
@@ -502,6 +489,13 @@ pub const HeadersParser = struct {
         return len;
     }
 
+    /// Returns whether or not the parser has finished parsing a complete
+    /// message. A message is only complete after the entire body has been read
+    /// and any trailing headers have been parsed.
+    pub fn isComplete(r: *HeadersParser) bool {
+        return r.done and r.state == .finished;
+    }
+
     pub const CheckCompleteHeadError = error{HttpHeadersOversize};
 
     /// Pushes `in` into the parser. Returns the number of bytes consumed by
@@ -532,12 +526,13 @@ pub const HeadersParser = struct {
     /// See `std.http.Client.Connection for an example of `conn`.
     pub fn read(r: *HeadersParser, conn: anytype, buffer: []u8, skip: bool) !usize {
         assert(r.state.isContent());
+        if (r.done) return 0;
+
         var out_index: usize = 0;
         while (true) {
             switch (r.state) {
-                .complete => return out_index,
                 .invalid, .start, .seen_n, .seen_r, .seen_rn, .seen_rnr => unreachable,
-                .headers_end => {
+                .finished => {
                     const data_avail = r.next_chunk_length;
 
                     if (skip) {
@@ -547,8 +542,7 @@ pub const HeadersParser = struct {
                         conn.drop(@intCast(nread));
                         r.next_chunk_length -= nread;
 
-                        if (r.next_chunk_length == 0 or nread == 0)
-                            r.state = .complete;
+                        if (r.next_chunk_length == 0 or nread == 0) r.done = true;
 
                         return out_index;
                     } else if (out_index < buffer.len) {
@@ -558,8 +552,7 @@ pub const HeadersParser = struct {
                         const nread = try conn.read(buffer[0..can_read]);
                         r.next_chunk_length -= nread;
 
-                        if (r.next_chunk_length == 0 or nread == 0)
-                            r.state = .complete;
+                        if (r.next_chunk_length == 0 or nread == 0) r.done = true;
 
                         return nread;
                     } else {
@@ -576,12 +569,14 @@ pub const HeadersParser = struct {
                         .invalid => return error.HttpChunkInvalid,
                         .chunk_data => if (r.next_chunk_length == 0) {
                             if (std.mem.eql(u8, conn.peek(), "\r\n")) {
-                                r.state = .complete;
+                                r.state = .finished;
+                                r.done = true;
                             } else {
-                                // The trailer section is formatted identically
-                                // to the header section.
+                                // The trailer section is formatted identically to the header section.
                                 r.state = .seen_rn;
                             }
+                            r.done = true;
+
                             return out_index;
                         },
                         else => return out_index,
@@ -619,21 +614,21 @@ pub const HeadersParser = struct {
 };
 
 inline fn int16(array: *const [2]u8) u16 {
-    return @bitCast(array.*);
+    return @as(u16, @bitCast(array.*));
 }
 
 inline fn int24(array: *const [3]u8) u24 {
-    return @bitCast(array.*);
+    return @as(u24, @bitCast(array.*));
 }
 
 inline fn int32(array: *const [4]u8) u32 {
-    return @bitCast(array.*);
+    return @as(u32, @bitCast(array.*));
 }
 
 inline fn intShift(comptime T: type, x: anytype) T {
     switch (@import("builtin").cpu.arch.endian()) {
-        .little => return @truncate(x >> (@bitSizeOf(@TypeOf(x)) - @bitSizeOf(T))),
-        .big => return @truncate(x),
+        .little => return @as(T, @truncate(x >> (@bitSizeOf(@TypeOf(x)) - @bitSizeOf(T)))),
+        .big => return @as(T, @truncate(x)),
     }
 }
 
lib/std/http/Server.zig
@@ -352,7 +352,7 @@ pub const Response = struct {
             return .reset;
         }
 
-        if (res.request.parser.state != .complete) {
+        if (!res.request.parser.done) {
             // If the response wasn't fully read, then we need to close the connection.
             res.connection.closing = true;
             return .closing;
@@ -447,12 +447,12 @@ pub const Response = struct {
     }
 
     fn transferRead(res: *Response, buf: []u8) TransferReadError!usize {
-        if (res.request.parser.state == .complete) return 0;
+        if (res.request.parser.done) return 0;
 
         var index: usize = 0;
         while (index == 0) {
             const amt = try res.request.parser.read(&res.connection, buf[index..], false);
-            if (amt == 0 and res.request.parser.state == .complete) break;
+            if (amt == 0 and res.request.parser.done) break;
             index += amt;
         }
 
@@ -502,9 +502,9 @@ pub const Response = struct {
                 if (res.request.content_length) |len| {
                     res.request.parser.next_chunk_length = len;
 
-                    if (len == 0) res.request.parser.state = .complete;
+                    if (len == 0) res.request.parser.done = true;
                 } else {
-                    res.request.parser.state = .complete;
+                    res.request.parser.done = true;
                 }
             },
             .chunked => {
@@ -513,7 +513,7 @@ pub const Response = struct {
             },
         }
 
-        if (res.request.parser.state != .complete) {
+        if (!res.request.parser.done) {
             switch (res.request.transfer_compression) {
                 .identity => res.request.compression = .none,
                 .compress, .@"x-compress" => return error.CompressionUnsupported,
test/standalone/http.zig
@@ -673,7 +673,7 @@ pub fn main() !void {
             var req = try client.open(.GET, uri, .{
                 .server_header_buffer = headers_buf,
             });
-            req.response.parser.state = .complete;
+            req.response.parser.done = true;
             req.connection.?.closing = false;
             requests[i] = req;
         }