Merge pull request #15416 from squeek502/http-response-headers-undefined

std.http: Always initialize `response.headers` in Client.request

Author: andrewrk

lib/std/http/Client.zig

@@ -645,7 +645,6 @@ pub const Request = struct {
                 if (req.response.parser.state.isContent()) break;
             }
 
-            req.response.headers = http.Headers{ .allocator = req.client.allocator, .owned = false };
             try req.response.parse(req.response.parser.header_bytes.items);
 
             if (req.response.status == .switching_protocols) {
@@ -765,7 +764,7 @@ pub const Request = struct {
             }
 
             if (has_trail) {
-                req.response.headers = http.Headers{ .allocator = req.client.allocator, .owned = false };
+                req.response.headers.clearRetainingCapacity();
 
                 // The response headers before the trailers are already guaranteed to be valid, so they will always be parsed again and cannot return an error.
                 // This will *only* fail for a malformed trailer.
@@ -1019,7 +1018,7 @@ pub fn request(client: *Client, method: http.Method, uri: Uri, headers: http.Hea
             .status = undefined,
             .reason = undefined,
             .version = undefined,
-            .headers = undefined,
+            .headers = http.Headers{ .allocator = client.allocator, .owned = false },
             .parser = switch (options.header_strategy) {
                 .dynamic => |max| proto.HeadersParser.initDynamic(max),
                 .static => |buf| proto.HeadersParser.initStatic(buf),

lib/std/http/Headers.zig

@@ -68,17 +68,7 @@ pub const Headers = struct {
     }
 
     pub fn deinit(headers: *Headers) void {
-        var it = headers.index.iterator();
-        while (it.next()) |entry| {
-            entry.value_ptr.deinit(headers.allocator);
-
-            if (headers.owned) headers.allocator.free(entry.key_ptr.*);
-        }
-
-        for (headers.list.items) |entry| {
-            if (headers.owned) headers.allocator.free(entry.value);
-        }
-
+        headers.deallocateIndexListsAndFields();
         headers.index.deinit(headers.allocator);
         headers.list.deinit(headers.allocator);
 
@@ -255,6 +245,39 @@ pub const Headers = struct {
 
         try out_stream.writeAll("\r\n");
     }
+
+    /// Frees all `HeaderIndexList`s within `index`
+    /// Frees names and values of all fields if they are owned.
+    fn deallocateIndexListsAndFields(headers: *Headers) void {
+        var it = headers.index.iterator();
+        while (it.next()) |entry| {
+            entry.value_ptr.deinit(headers.allocator);
+
+            if (headers.owned) headers.allocator.free(entry.key_ptr.*);
+        }
+
+        if (headers.owned) {
+            for (headers.list.items) |entry| {
+                headers.allocator.free(entry.value);
+            }
+        }
+    }
+
+    /// Clears and frees the underlying data structures.
+    /// Frees names and values if they are owned.
+    pub fn clearAndFree(headers: *Headers) void {
+        headers.deallocateIndexListsAndFields();
+        headers.index.clearAndFree(headers.allocator);
+        headers.list.clearAndFree(headers.allocator);
+    }
+
+    /// Clears the underlying data structures while retaining their capacities.
+    /// Frees names and values if they are owned.
+    pub fn clearRetainingCapacity(headers: *Headers) void {
+        headers.deallocateIndexListsAndFields();
+        headers.index.clearRetainingCapacity();
+        headers.list.clearRetainingCapacity();
+    }
 };
 
 test "Headers.append" {
@@ -384,3 +407,42 @@ test "Headers consistency" {
     try h.formatCommaSeparated("foo", writer);
     try testing.expectEqualStrings("foo: bar, baz\r\n", fbs.getWritten());
 }
+
+test "Headers.clearRetainingCapacity and clearAndFree" {
+    var h = Headers.init(std.testing.allocator);
+    defer h.deinit();
+
+    h.clearRetainingCapacity();
+
+    try h.append("foo", "bar");
+    try h.append("bar", "world");
+    try h.append("foo", "baz");
+    try h.append("baz", "hello");
+    try testing.expectEqual(@as(usize, 4), h.list.items.len);
+    try testing.expectEqual(@as(usize, 3), h.index.count());
+    const list_capacity = h.list.capacity;
+    const index_capacity = h.index.capacity();
+
+    h.clearRetainingCapacity();
+    try testing.expectEqual(@as(usize, 0), h.list.items.len);
+    try testing.expectEqual(@as(usize, 0), h.index.count());
+    try testing.expectEqual(list_capacity, h.list.capacity);
+    try testing.expectEqual(index_capacity, h.index.capacity());
+
+    try h.append("foo", "bar");
+    try h.append("bar", "world");
+    try h.append("foo", "baz");
+    try h.append("baz", "hello");
+    try testing.expectEqual(@as(usize, 4), h.list.items.len);
+    try testing.expectEqual(@as(usize, 3), h.index.count());
+    // Capacity should still be the same since we shouldn't have needed to grow
+    // when adding back the same fields
+    try testing.expectEqual(list_capacity, h.list.capacity);
+    try testing.expectEqual(index_capacity, h.index.capacity());
+
+    h.clearAndFree();
+    try testing.expectEqual(@as(usize, 0), h.list.items.len);
+    try testing.expectEqual(@as(usize, 0), h.index.count());
+    try testing.expectEqual(@as(usize, 0), h.list.capacity);
+    try testing.expectEqual(@as(usize, 0), h.index.capacity());
+}