cache headers along with response

src/browser/HttpClient.zig

@@ -33,6 +33,7 @@ const RobotStore = Robots.RobotStore;
 const WebBotAuth = @import("../network/WebBotAuth.zig");
 
 const Cache = @import("../network/cache/Cache.zig");
+const CacheMetadata = Cache.CachedMetadata;
 const CachedResponse = Cache.CachedResponse;
 
 const Allocator = std.mem.Allocator;
@@ -907,6 +908,23 @@ fn processMessages(self: *Client) !bool {
             }
         }
 
+        const allocator = transfer.arena.allocator();
+        var header_list: std.ArrayList(Net.Header) = .empty;
+
+        var it = transfer.responseHeaderIterator();
+        while (it.next()) |hdr| {
+            header_list.append(
+                allocator,
+                .{
+                    .name = try allocator.dupe(u8, hdr.name),
+                    .value = try allocator.dupe(u8, hdr.value),
+                },
+            ) catch |err| {
+                log.warn(.http, "cache header collect failed", .{ .err = err });
+                break;
+            };
+        }
+
         // release it ASAP so that it's available; some done_callbacks
         // will load more resources.
         self.endTransfer(transfer);
@@ -941,37 +959,36 @@ fn processMessages(self: *Client) !bool {
                 continue;
             };
 
-            if (self.network.cache) |*cache| {
-                var headers = &transfer.response_header.?;
+            cache: {
+                if (self.network.cache) |*cache| {
+                    const headers = &transfer.response_header.?;
 
-                if (transfer.req.method == .GET and headers.status == 200) {
-                    cache.put(
+                    const metadata = try CacheMetadata.fromHeaders(
                         transfer.req.url,
-                        .{
-                            .url = transfer.req.url,
-                            .content_type = headers.contentType() orelse "application/octet-stream",
-                            .status = headers.status,
-                            .stored_at = std.time.timestamp(),
-                            .age_at_store = 0,
-                            .max_age = 3600,
-                            .etag = null,
-                            .last_modified = null,
-                            .must_revalidate = false,
-                            .no_cache = false,
-                            .immutable = false,
-                            .vary = null,
-                        },
+                        headers.status,
+                        std.time.timestamp(),
+                        header_list.items,
+                    ) orelse break :cache;
+
+                    // TODO: Support Vary Keying
+                    const cache_key = transfer.req.url;
+
+                    log.err(.browser, "http cache", .{ .key = cache_key, .metadata = metadata });
+
+                    cache.put(
+                        cache_key,
+                        metadata,
                         transfer.body.items,
                     ) catch |err| log.warn(.http, "cache put failed", .{ .err = err });
                     log.debug(.browser, "http.cache.put", .{ .url = transfer.req.url });
                 }
             }
-
-            transfer.req.notification.dispatch(.http_request_done, &.{
-                .transfer = transfer,
-            });
-            processed = true;
         }
+
+        transfer.req.notification.dispatch(.http_request_done, &.{
+            .transfer = transfer,
+        });
+        processed = true;
     }
     return processed;
 }
@@ -1133,8 +1150,7 @@ pub const Response = struct {
     pub fn headerIterator(self: Response) HeaderIterator {
         return switch (self.inner) {
             .live => |live| live.responseHeaderIterator(),
-            // TODO: Cache HTTP Headers
-            .cached => unreachable,
+            .cached => |c| HeaderIterator{ .list = .{ .list = c.metadata.headers } },
         };
     }
 

src/network/cache/Cache.zig

@@ -17,6 +17,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
+const Http = @import("../http.zig");
 const FsCache = @import("FsCache.zig");
 
 /// A browser-wide cache for resources across the network.
@@ -39,6 +40,55 @@ pub fn put(self: *Cache, key: []const u8, metadata: CachedMetadata, body: []cons
     };
 }
 
+pub const CacheControl = struct {
+    max_age: ?u64 = null,
+    must_revalidate: bool = false,
+    no_cache: bool = false,
+    no_store: bool = false,
+    immutable: bool = false,
+
+    pub fn parse(value: []const u8) CacheControl {
+        var cc: CacheControl = .{};
+
+        var iter = std.mem.splitScalar(u8, value, ',');
+        while (iter.next()) |part| {
+            const directive = std.mem.trim(u8, part, &std.ascii.whitespace);
+            if (std.ascii.eqlIgnoreCase(directive, "no-store")) {
+                cc.no_store = true;
+            } else if (std.ascii.eqlIgnoreCase(directive, "no-cache")) {
+                cc.no_cache = true;
+            } else if (std.ascii.eqlIgnoreCase(directive, "must-revalidate")) {
+                cc.must_revalidate = true;
+            } else if (std.ascii.eqlIgnoreCase(directive, "immutable")) {
+                cc.immutable = true;
+            } else if (std.ascii.startsWithIgnoreCase(directive, "max-age=")) {
+                cc.max_age = std.fmt.parseInt(u64, directive[8..], 10) catch null;
+            } else if (std.ascii.startsWithIgnoreCase(directive, "s-maxage=")) {
+                // s-maxage takes precedence over max-age
+                cc.max_age = std.fmt.parseInt(u64, directive[9..], 10) catch cc.max_age;
+            }
+        }
+        return cc;
+    }
+};
+
+pub const Vary = union(enum) {
+    wildcard: void,
+    value: []const u8,
+
+    pub fn parse(value: []const u8) Vary {
+        if (std.mem.eql(u8, value, "*")) return .wildcard;
+        return .{ .value = value };
+    }
+
+    pub fn toString(self: Vary) []const u8 {
+        return switch (self) {
+            .wildcard => "*",
+            .value => |v| v,
+        };
+    }
+};
+
 pub const CachedMetadata = struct {
     url: [:0]const u8,
     content_type: []const u8,
@@ -52,17 +102,74 @@ pub const CachedMetadata = struct {
     etag: ?[]const u8,
     // for If-Modified-Since
     last_modified: ?[]const u8,
+    // If non-null, must be incorporated into cache key.
+    vary: ?[]const u8,
 
     must_revalidate: bool,
     no_cache: bool,
     immutable: bool,
 
-    // If non-null, must be incorporated into cache key.
-    vary: ?[]const u8,
+    headers: []const Http.Header,
+
+    pub fn fromHeaders(
+        url: [:0]const u8,
+        status: u16,
+        timestamp: i64,
+        headers: []const Http.Header,
+    ) !?CachedMetadata {
+        var cc: CacheControl = .{};
+        var vary: ?Vary = null;
+        var etag: ?[]const u8 = null;
+        var last_modified: ?[]const u8 = null;
+        var age_at_store: u64 = 0;
+        var content_type: []const u8 = "application/octet-stream";
+
+        for (headers) |hdr| {
+            if (std.ascii.eqlIgnoreCase(hdr.name, "cache-control")) {
+                cc = CacheControl.parse(hdr.value);
+            } else if (std.ascii.eqlIgnoreCase(hdr.name, "etag")) {
+                etag = hdr.value;
+            } else if (std.ascii.eqlIgnoreCase(hdr.name, "last-modified")) {
+                last_modified = hdr.value;
+            } else if (std.ascii.eqlIgnoreCase(hdr.name, "vary")) {
+                vary = Vary.parse(hdr.value);
+            } else if (std.ascii.eqlIgnoreCase(hdr.name, "age")) {
+                age_at_store = std.fmt.parseInt(u64, hdr.value, 10) catch 0;
+            } else if (std.ascii.eqlIgnoreCase(hdr.name, "content-type")) {
+                content_type = hdr.value;
+            }
+        }
+
+        // return null for uncacheable responses
+        if (cc.no_store) return null;
+        if (vary) |v| if (v == .wildcard) return null;
+        const resolved_max_age = cc.max_age orelse return null;
+
+        return .{
+            .url = url,
+            .content_type = content_type,
+            .status = status,
+            .stored_at = timestamp,
+            .age_at_store = age_at_store,
+            .max_age = resolved_max_age,
+            .etag = etag,
+            .last_modified = last_modified,
+            .must_revalidate = cc.must_revalidate,
+            .no_cache = cc.no_cache,
+            .immutable = cc.immutable,
+            .vary = if (vary) |v| v.toString() else null,
+            .headers = headers,
+        };
+    }
 
     pub fn deinit(self: CachedMetadata, allocator: std.mem.Allocator) void {
         allocator.free(self.url);
         allocator.free(self.content_type);
+        for (self.headers) |header| {
+            allocator.free(header.name);
+            allocator.free(header.value);
+        }
+        allocator.free(self.headers);
         if (self.etag) |e| allocator.free(e);
         if (self.last_modified) |lm| allocator.free(lm);
         if (self.vary) |v| allocator.free(v);

src/network/cache/FsCache.zig

@@ -18,6 +18,7 @@
 
 const std = @import("std");
 const Cache = @import("Cache.zig");
+const Http = @import("../http.zig");
 const CachedMetadata = Cache.CachedMetadata;
 const CachedResponse = Cache.CachedResponse;
 
@@ -73,6 +74,12 @@ fn serializeMeta(writer: *std.Io.Writer, meta: *const CachedMetadata) !void {
         meta.immutable,
     });
     try writer.flush();
+
+    try writer.print("{d}\n", .{meta.headers.len});
+    for (meta.headers) |hdr| {
+        try writer.print("{s}\n{s}\n", .{ hdr.name, hdr.value });
+    }
+    try writer.flush();
 }
 
 fn deserializeMetaOptionalString(bytes: []const u8) ?[]const u8 {
@@ -145,6 +152,32 @@ fn deserializeMeta(allocator: std.mem.Allocator, file: std.fs.File) !CachedMetad
         break :blk try deserializeMetaBoolean(line);
     };
 
+    const headers = blk: {
+        const line = try reader.takeDelimiter('\n') orelse return error.Malformed;
+        const count = std.fmt.parseInt(usize, line, 10) catch return error.Malformed;
+
+        const hdrs = try allocator.alloc(Http.Header, count);
+        errdefer allocator.free(hdrs);
+
+        for (hdrs) |*hdr| {
+            const name = try reader.takeDelimiter('\n') orelse return error.Malformed;
+            const value = try reader.takeDelimiter('\n') orelse return error.Malformed;
+            hdr.* = .{
+                .name = try allocator.dupe(u8, name),
+                .value = try allocator.dupe(u8, value),
+            };
+        }
+
+        break :blk hdrs;
+    };
+    errdefer {
+        for (headers) |hdr| {
+            allocator.free(hdr.name);
+            allocator.free(hdr.value);
+        }
+        allocator.free(headers);
+    }
+
     return .{
         .url = url,
         .content_type = content_type,
@@ -158,6 +191,7 @@ fn deserializeMeta(allocator: std.mem.Allocator, file: std.fs.File) !CachedMetad
         .no_cache = no_cache,
         .immutable = immutable,
         .vary = vary,
+        .headers = headers,
     };
 }