browser/src/network/cache/SqliteCache.zig

// Copyright (C) 2023-2026  Lightpanda (Selecy SAS)
//
// Francis Bouvier <francis@lightpanda.io>
// Pierre Tachoire <pierre@lightpanda.io>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

const std = @import("std");
const lp = @import("lightpanda");

const Cache = @import("Cache.zig");

const log = lp.log;
const CacheRequest = Cache.CacheRequest;
const RenewResponse = Cache.RenewResponse;
const CachedMetadata = Cache.CachedMetadata;
const CachedResponse = Cache.CachedResponse;

const Http = @import("../http.zig");
const Blob = @import("../../storage/sqlite/Sqlite.zig").Blob;
const Pool = @import("../../storage/sqlite/Pool.zig");
const Conn = @import("../../storage/sqlite/Sqlite.zig").Conn;
const Migration = @import("../../storage/sqlite/Sqlite.zig").Migration;
const Migrations = @import("../../storage/sqlite/Sqlite.zig").Migrations;

pub const SqliteCache = @This();

allocator: std.mem.Allocator,
pool: Pool,

const cache_migrations: []const Migration = &.{
    .{ .sql =
    \\ create table metadata (
    \\      url               text not null primary key,
    \\      status            integer not null,
    \\      stored_at         integer not null,
    \\      age_at_store      integer not null,
    \\      max_age           integer not null,
    \\      must_revalidate   integer not null,
    \\      etag              text,
    \\      last_modified     text
    \\ ) strict
    },
    .{ .sql =
    \\ create table body (
    \\      url               text not null primary key,
    \\      data              blob not null,
    \\      foreign key (url) references metadata(url) on delete cascade
    \\ ) strict
    },
    .{ .sql =
    \\ create table header (
    \\      url               text not null,
    \\      name              text not null,
    \\      value             blob not null,
    \\      vary              integer not null,
    \\      foreign key (url) references metadata(url) on delete cascade
    \\ ) strict
    },
    .{ .sql = "create index header_url on header(url)" },
};

pub const SqliteCachePath = union(enum) { path: []const u8, memory };

pub fn init(allocator: std.mem.Allocator, path: SqliteCachePath) !SqliteCache {
    var pool = switch (path) {
        .memory => try Pool.init(allocator, ":memory:"),
        .path => |cache_dir| blk: {
            std.Io.Dir.cwd().createDirPath(lp.io, cache_dir) catch |e| {
                log.err(
                    .cache,
                    "failed to make path",
                    .{ .kind = "httpCacheSqlitePath", .path = cache_dir, .err = e },
                );
                return e;
            };

            const full_path = try std.fmt.allocPrintSentinel(
                allocator,
                "{s}/cache.db",
                .{std.mem.trimEnd(u8, cache_dir, &.{'/'})},
                0,
            );
            defer allocator.free(full_path);
            break :blk try Pool.init(allocator, full_path);
        },
    };
    errdefer pool.deinit(allocator);

    var version: usize = 0;

    {
        const conn = try pool.acquire();
        defer pool.release(conn);

        try conn.exec("pragma journal_mode=wal", .{});
        version = try Migrations.run(conn, cache_migrations);
    }

    for (pool.conns) |conn| {
        try conn.exec("pragma foreign_keys=on", .{});
    }

    log.info(.cache, "sqlite cache initialized", .{ .path = path, .version = version });
    return .{ .allocator = allocator, .pool = pool };
}

pub fn deinit(self: *SqliteCache) void {
    self.pool.deinit(self.allocator);
}

fn loadMetadata(conn: Conn, arena: std.mem.Allocator, url: []const u8) !?CachedMetadata {
    var entry = try conn.row(
        \\ select status, stored_at, age_at_store,
        \\      max_age, must_revalidate, etag, last_modified
        \\ from metadata
        \\ where url = $1
    , .{url}) orelse return null;
    defer entry.deinit();

    const status: u16 = @intCast(entry.get(i64, 0));
    const stored_at: u64 = @intCast(entry.get(i64, 1));
    const age_at_store = entry.get(i64, 2);
    const max_age: u64 = @intCast(entry.get(i64, 3));
    const must_revalidate = entry.get(bool, 4);
    const etag = if (entry.get(?[]const u8, 5)) |opt| try arena.dupe(u8, opt) else null;
    const last_modified = if (entry.get(?[]const u8, 6)) |opt| try arena.dupe(u8, opt) else null;

    var header_rows = try conn.rows(
        "select name, value, vary from header where url = $1",
        .{url},
    );
    defer header_rows.deinit();

    var headers: std.ArrayList(Http.Header) = .empty;
    var vary_headers: std.ArrayList(Http.Header) = .empty;
    var content_type: []const u8 = "application/octet-stream";

    while (try header_rows.next()) |row| {
        const name = try arena.dupe(u8, row.get([]const u8, 0));
        const value = try arena.dupe(u8, row.get(Blob, 1).data);
        const vary = row.get(bool, 2);

        if (std.ascii.eqlIgnoreCase(name, "content-type")) {
            content_type = value;
        }

        const h = Http.Header{ .name = name, .value = value };
        if (vary) {
            try vary_headers.append(arena, h);
        } else {
            try headers.append(arena, h);
        }
    }

    return CachedMetadata{
        .url = try arena.dupeZ(u8, url),
        .content_type = content_type,
        .status = status,
        .stored_at = stored_at,
        .age_at_store = @intCast(age_at_store),
        .cache_control = .{
            .max_age = max_age,
            .must_revalidate = must_revalidate,
        },
        .headers = headers.items,
        .vary_headers = vary_headers.items,
        .etag = etag,
        .last_modified = last_modified,
    };
}

fn loadBody(conn: Conn, arena: std.mem.Allocator, url: []const u8) !?[]const u8 {
    const body_entry = try conn.row(
        "select data from body where url = $1",
        .{url},
    ) orelse return null;
    defer body_entry.deinit();

    return try arena.dupe(u8, body_entry.get(Blob, 0).data);
}

fn insertMetadata(conn: Conn, meta: CachedMetadata, body: []const u8) !void {
    try conn.exec(
        \\ insert or replace into metadata
        \\     (url, status, stored_at, age_at_store, max_age, must_revalidate, etag, last_modified)
        \\ values ($1, $2, $3, $4, $5, $6, $7, $8)
    , .{
        meta.url,
        @as(i64, @intCast(meta.status)),
        meta.stored_at,
        @as(i64, @intCast(meta.age_at_store)),
        @as(i64, @intCast(meta.cache_control.max_age)),
        meta.cache_control.must_revalidate,
        meta.etag,
        meta.last_modified,
    });

    try conn.exec(
        "insert into body (url, data) values ($1, $2)",
        .{ meta.url, Blob{ .data = body } },
    );

    var lower_name: [256]u8 = undefined;
    for (meta.headers) |h| {
        if (h.name.len > lower_name.len) return error.HeaderNameTooLong;
        const name = std.ascii.lowerString(lower_name[0..h.name.len], h.name);
        try conn.exec(
            "insert into header (url, name, value, vary) values ($1, $2, $3, false)",
            .{ meta.url, name, Blob{ .data = h.value } },
        );
    }
    for (meta.vary_headers) |h| {
        if (h.name.len > lower_name.len) return error.HeaderNameTooLong;
        const name = std.ascii.lowerString(lower_name[0..h.name.len], h.name);
        try conn.exec(
            "insert into header (url, name, value, vary) values ($1, $2, $3, true)",
            .{ meta.url, name, Blob{ .data = h.value } },
        );
    }
}

fn updateMetadata(conn: Conn, meta: CachedMetadata) !void {
    try conn.exec(
        \\ update metadata
        \\ set status = $1, stored_at = $2, age_at_store = $3, max_age = $4, must_revalidate = $5, etag = $6, last_modified = $7
        \\ where url = $8
    , .{
        @as(i64, @intCast(meta.status)),
        meta.stored_at,
        @as(i64, @intCast(meta.age_at_store)),
        @as(i64, @intCast(meta.cache_control.max_age)),
        meta.cache_control.must_revalidate,
        meta.etag,
        meta.last_modified,
        meta.url,
    });

    try conn.exec("delete from header where url = $1 and vary = false", .{meta.url});

    var lower_name: [256]u8 = undefined;
    for (meta.headers) |h| {
        if (h.name.len > lower_name.len) return error.HeaderNameTooLong;
        const name = std.ascii.lowerString(lower_name[0..h.name.len], h.name);
        try conn.exec(
            "insert into header (url, name, value, vary) values ($1, $2, $3, false)",
            .{ meta.url, name, Blob{ .data = h.value } },
        );
    }
}

pub fn get(self: *SqliteCache, arena: std.mem.Allocator, req: CacheRequest) !?CachedResponse {
    const conn = try self.pool.acquire();
    defer self.pool.release(conn);

    try conn.begin();
    defer conn.rollback() catch {};

    const metadata = try loadMetadata(conn, arena, req.url) orelse {
        log.debug(.cache, "miss", .{ .url = req.url, .reason = "missing" });
        return null;
    };

    // Vary matching.
    for (metadata.vary_headers) |vary_hdr| {
        const incoming = for (req.request_headers) |h| {
            if (std.ascii.eqlIgnoreCase(h.name, vary_hdr.name)) break h.value;
        } else "";

        if (!std.ascii.eqlIgnoreCase(vary_hdr.value, incoming)) {
            log.debug(.cache, "miss", .{
                .url = req.url,
                .reason = "vary mismatch",
                .header = vary_hdr.name,
                .expected = vary_hdr.value,
                .got = incoming,
            });
            return null;
        }
    }

    const body = try loadBody(conn, arena, req.url) orelse {
        log.debug(.cache, "miss", .{ .url = req.url, .reason = "missing body " });
        return null;
    };
    const expired = metadata.isStale(req.timestamp);
    log.debug(.cache, "hit", .{ .url = req.url, .expired = expired });

    return .{
        .metadata = metadata,
        .data = .{ .buffer = body },
        .expired = expired,
    };
}

pub fn put(self: *SqliteCache, meta: CachedMetadata, body: []const u8) !void {
    const conn = try self.pool.acquire();
    defer self.pool.release(conn);

    try conn.begin();
    errdefer conn.rollback() catch {};

    try insertMetadata(conn, meta, body);
    try conn.commit();

    log.debug(.cache, "put", .{ .url = meta.url, .body_len = body.len });
}

pub fn clear(self: *SqliteCache) !void {
    const conn = try self.pool.acquire();
    defer self.pool.release(conn);

    try conn.exec("delete from metadata", .{});
    log.debug(.cache, "clear", .{});
}

pub fn evict(self: *SqliteCache, url: []const u8) void {
    const conn = self.pool.acquire() catch |err| {
        log.err(.cache, "sqlite acquire", .{ .url = url, .err = err });
        return;
    };
    defer self.pool.release(conn);

    conn.exec("delete from metadata where url = $1", .{url}) catch |err| {
        log.err(.cache, "delete from cache", .{ .url = url, .err = err });
        return;
    };

    log.debug(.cache, "evict", .{ .url = url });
}

pub fn renew(self: *SqliteCache, arena: std.mem.Allocator, req: RenewResponse) !void {
    const conn = try self.pool.acquire();
    defer self.pool.release(conn);

    try conn.begin();
    errdefer conn.rollback() catch {};

    var metadata = try loadMetadata(conn, arena, req.url) orelse {
        log.debug(.cache, "miss", .{ .url = req.url, .reason = "missing" });
        return error.CacheEntryNotFound;
    };

    metadata.renew(req);

    try updateMetadata(conn, metadata);
    try conn.commit();

    log.debug(.cache, "renewed", .{
        .url = req.url,
        .timestamp = req.timestamp,
    });
}

const testing = std.testing;

fn setupCache(allocator: std.mem.Allocator) !Cache {
    return Cache{ .kind = .{ .sqlite = try .init(allocator, .memory) } };
}

test "SqliteCache: Migrations" {
    const allocator = testing.allocator;
    var pool = try Pool.init(allocator, ":memory:");
    defer pool.deinit(allocator);

    const conn = try pool.acquire();
    defer pool.release(conn);

    _ = try Migrations.run(conn, cache_migrations);
}

test "SqliteCache: basic put and get" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: u64 = @intCast(std.Io.Timestamp.now(testing.io, .boot).toSeconds());
    const meta = CachedMetadata{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600, .must_revalidate = false },
        .headers = &.{.{ .name = "Content-Type", .value = "text/html" }},
        .vary_headers = &.{},
    };

    try cache.put(meta, "hello world");

    const result = try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now,
            .request_headers = &.{},
        },
    ) orelse return error.CacheMiss;

    try testing.expectEqualStrings("hello world", result.data.buffer);
    try testing.expectEqual(@as(u16, 200), result.metadata.status);
    try testing.expectEqual(false, result.expired);
    try testing.expectEqualStrings("text/html", result.metadata.content_type);
}

test "SqliteCache: get expiration" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now = 5000;
    const max_age = 1000;

    const meta = CachedMetadata{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 900,
        .cache_control = .{ .max_age = max_age },
        .headers = &.{},
        .vary_headers = &.{},
    };

    try cache.put(meta, "hello world");

    // age = 50 + 900 = 950 < 1000: fresh
    const fresh = try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now + 50,
            .request_headers = &.{},
        },
    ) orelse return error.CacheMiss;
    try testing.expectEqual(false, fresh.expired);

    // age = 200 + 900 = 1100 >= 1000: stale
    const stale = try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now + 200,
            .request_headers = &.{},
        },
    ) orelse return error.CacheMiss;
    try testing.expectEqual(true, stale.expired);
}

test "SqliteCache: put override" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    {
        const meta = CachedMetadata{
            .url = "https://example.com",
            .content_type = "text/html",
            .status = 200,
            .stored_at = 5000,
            .age_at_store = 0,
            .cache_control = .{ .max_age = 1000 },
            .headers = &.{},
            .vary_headers = &.{},
        };
        try cache.put(meta, "hello world");

        const result = try cache.get(
            arena.allocator(),
            .{
                .url = "https://example.com",
                .timestamp = 5000,
                .request_headers = &.{},
            },
        ) orelse return error.CacheMiss;
        try testing.expectEqualStrings("hello world", result.data.buffer);
    }

    {
        const meta = CachedMetadata{
            .url = "https://example.com",
            .content_type = "text/html",
            .status = 200,
            .stored_at = 10000,
            .age_at_store = 0,
            .cache_control = .{ .max_age = 2000 },
            .headers = &.{},
            .vary_headers = &.{},
        };
        try cache.put(meta, "goodbye world");

        const result = try cache.get(
            arena.allocator(),
            .{
                .url = "https://example.com",
                .timestamp = 10000,
                .request_headers = &.{},
            },
        ) orelse return error.CacheMiss;
        try testing.expectEqualStrings("goodbye world", result.data.buffer);
    }
}

test "SqliteCache: vary hit and miss" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: u64 = @intCast(std.Io.Timestamp.now(testing.io, .boot).toSeconds());
    const meta = CachedMetadata{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600 },
        .headers = &.{},
        .vary_headers = &.{
            .{ .name = "Accept-Encoding", .value = "gzip" },
        },
    };

    try cache.put(meta, "hello world");

    const hit = try cache.get(arena.allocator(), .{
        .url = "https://example.com",
        .timestamp = now,
        .request_headers = &.{.{ .name = "Accept-Encoding", .value = "gzip" }},
    }) orelse return error.CacheMiss;
    try testing.expectEqualStrings("hello world", hit.data.buffer);

    try testing.expectEqual(null, try cache.get(arena.allocator(), .{
        .url = "https://example.com",
        .timestamp = now,
        .request_headers = &.{.{ .name = "Accept-Encoding", .value = "br" }},
    }));

    try testing.expectEqual(null, try cache.get(arena.allocator(), .{
        .url = "https://example.com",
        .timestamp = now,
        .request_headers = &.{},
    }));
}

test "SqliteCache: vary multiple headers" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: u64 = @intCast(std.Io.Timestamp.now(testing.io, .boot).toSeconds());
    const meta = CachedMetadata{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600 },
        .headers = &.{},
        .vary_headers = &.{
            .{ .name = "Accept-Encoding", .value = "gzip" },
            .{ .name = "Accept-Language", .value = "en" },
        },
    };

    try cache.put(meta, "hello world");

    const hit = try cache.get(arena.allocator(), .{
        .url = "https://example.com",
        .timestamp = now,
        .request_headers = &.{
            .{ .name = "Accept-Encoding", .value = "gzip" },
            .{ .name = "Accept-Language", .value = "en" },
        },
    }) orelse return error.CacheMiss;
    try testing.expectEqualStrings("hello world", hit.data.buffer);

    try testing.expectEqual(null, try cache.get(arena.allocator(), .{
        .url = "https://example.com",
        .timestamp = now,
        .request_headers = &.{
            .{ .name = "Accept-Encoding", .value = "gzip" },
            .{ .name = "Accept-Language", .value = "fr" },
        },
    }));
}

test "SqliteCache: clear removes all entries" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: u64 = @intCast(std.Io.Timestamp.now(testing.io, .boot).toSeconds());
    try cache.put(.{
        .url = "https://example.com/a",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600 },
        .headers = &.{},
        .vary_headers = &.{},
    }, "body a");

    try cache.put(.{
        .url = "https://example.com/b",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600 },
        .headers = &.{},
        .vary_headers = &.{},
    }, "body b");

    try testing.expect(null != try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com/a",
            .timestamp = now,
            .request_headers = &.{},
        },
    ));
    try testing.expect(null != try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com/b",
            .timestamp = now,
            .request_headers = &.{},
        },
    ));

    try cache.clear();

    try testing.expectEqual(null, try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com/a",
            .timestamp = now,
            .request_headers = &.{},
        },
    ));
    try testing.expectEqual(null, try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com/b",
            .timestamp = now,
            .request_headers = &.{},
        },
    ));
}

test "SqliteCache: put after clear works" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: u64 = @intCast(std.Io.Timestamp.now(testing.io, .boot).toSeconds());
    const meta = CachedMetadata{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600 },
        .headers = &.{},
        .vary_headers = &.{},
    };

    try cache.put(meta, "before clear");
    try cache.clear();

    try testing.expectEqual(null, try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now,
            .request_headers = &.{},
        },
    ));

    try cache.put(meta, "after clear");
    const result = try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now,
            .request_headers = &.{},
        },
    ) orelse return error.CacheMiss;
    try testing.expectEqualStrings("after clear", result.data.buffer);
}

test "SqliteCache: evict removes entry" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: u64 = @intCast(std.Io.Timestamp.now(testing.io, .boot).toSeconds());
    const meta = CachedMetadata{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600 },
        .headers = &.{},
        .vary_headers = &.{},
    };

    try cache.put(meta, "hello world");

    _ = try cache.get(
        arena.allocator(),
        .{ .url = "https://example.com", .timestamp = now, .request_headers = &.{} },
    ) orelse return error.CacheMiss;

    cache.evict("https://example.com");

    try testing.expectEqual(null, try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now,
            .request_headers = &.{},
        },
    ));
}

test "SqliteCache: renew refreshes expiry" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: i64 = 5000;
    try cache.put(.{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 1000 },
        .headers = &.{},
        .vary_headers = &.{},
    }, "hello world");

    try cache.renew(
        arena.allocator(),
        .{ .url = "https://example.com", .timestamp = now + 500, .headers = &.{} },
    );

    // Clock reset to now+500, so still fresh at now+1200
    const fresh = try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now + 1200,
            .request_headers = &.{},
        },
    ) orelse return error.CacheMiss;
    try testing.expectEqual(false, fresh.expired);

    // Expires at now+500+1000 = now+1500
    const stale = try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now + 1500,
            .request_headers = &.{},
        },
    ) orelse return error.CacheMiss;
    try testing.expectEqual(true, stale.expired);
}

test "SqliteCache: renew preserves body" {
    var cache = try setupCache(testing.allocator);
    defer cache.deinit();

    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();

    const now: u64 = @intCast(std.Io.Timestamp.now(testing.io, .boot).toSeconds());
    try cache.put(.{
        .url = "https://example.com",
        .content_type = "text/html",
        .status = 200,
        .stored_at = now,
        .age_at_store = 0,
        .cache_control = .{ .max_age = 600 },
        .headers = &.{},
        .vary_headers = &.{},
    }, "original body");

    try cache.renew(
        arena.allocator(),
        .{ .url = "https://example.com", .timestamp = now + 100, .headers = &.{} },
    );

    const result = try cache.get(
        arena.allocator(),
        .{
            .url = "https://example.com",
            .timestamp = now + 100,
            .request_headers = &.{},
        },
    ) orelse return error.CacheMiss;
    try testing.expectEqualStrings("original body", result.data.buffer);
}