/* * Copyright (c) 2022-2023, Linus Groh * Copyright (c) 2024, Jelle Raaijmakers * * SPDX-License-Identifier: BSD-2-Clause */ #include #include #include #include #include #include #include #include #include namespace Web::Fetch::Infrastructure { GC_DEFINE_ALLOCATOR(Body); // https://mimesniff.spec.whatwg.org/#reading-the-resource-header // To read the resource header, a user agent MUST read bytes of the resource until one of the following conditions is met: // - the end of the resource is reached // - 1445 or more bytes have been read static constexpr size_t MAX_SNIFF_BYTES = 1445; static Body::SourceTypeInternal to_source_type_internal(Body::SourceType&& source_type) { return source_type.visit( [](Empty) -> Body::SourceTypeInternal { return Empty {}; }, [](ByteBuffer& buffer) -> Body::SourceTypeInternal { return move(buffer); }, [](GC::Root const& blob) -> Body::SourceTypeInternal { return GC::Ref { *blob }; }); } GC::Ref Body::create(JS::VM& vm, GC::Ref stream) { return vm.heap().allocate(stream); } GC::Ref Body::create(JS::VM& vm, GC::Ref stream, SourceType source, Optional length) { return create(vm, stream, to_source_type_internal(move(source)), length); } GC::Ref Body::create(JS::VM& vm, GC::Ref stream, SourceTypeInternal source, Optional length) { return vm.heap().allocate(stream, source, length); } Body::Body(GC::Ref stream) : m_stream(stream) { } Body::Body(GC::Ref stream, SourceTypeInternal source, Optional length) : m_stream(stream) , m_source(move(source)) , m_length(move(length)) { } void Body::visit_edges(Cell::Visitor& visitor) { Base::visit_edges(visitor); visitor.visit(m_stream); visitor.visit(m_sniff_bytes_callback); m_source.visit( [&](GC::Ref const& blob) { visitor.visit(blob); }, [](auto const&) {}); } void Body::append_sniff_bytes(ReadonlyBytes bytes) { if (m_sniff_bytes_complete) return; size_t space_remaining = MAX_SNIFF_BYTES - m_sniff_bytes.size(); if (space_remaining == 0) { set_sniff_bytes_complete(); return; } size_t to_append = min(bytes.size(), space_remaining); m_sniff_bytes.append(bytes.slice(0, to_append)); if (m_sniff_bytes.size() >= MAX_SNIFF_BYTES) set_sniff_bytes_complete(); } void Body::set_sniff_bytes_complete() { if (m_sniff_bytes_complete) return; m_sniff_bytes_complete = true; if (m_sniff_bytes_callback) { auto callback = exchange(m_sniff_bytes_callback, nullptr); callback->function()(m_sniff_bytes); } } Optional Body::sniff_bytes_if_available() const { // Non-streaming body: source has bytes if (m_source.has()) { auto const& buffer = m_source.get(); return buffer.bytes().slice(0, min(buffer.size(), MAX_SNIFF_BYTES)); } if (m_source.has>()) { auto raw = m_source.get>()->raw_bytes(); return raw.slice(0, min(raw.size(), MAX_SNIFF_BYTES)); } // Streaming body: bytes captured during fetch if (m_sniff_bytes_complete) return m_sniff_bytes; // Still waiting for bytes return {}; } void Body::wait_for_sniff_bytes(SniffBytesCallback on_ready) { if (auto bytes = sniff_bytes_if_available(); bytes.has_value()) { on_ready->function()(bytes.value()); return; } // Wait for bytes to arrive m_sniff_bytes_callback = on_ready; } // https://fetch.spec.whatwg.org/#concept-body-clone GC::Ref Body::clone(JS::Realm& realm) { HTML::TemporaryExecutionContext execution_context { realm, HTML::TemporaryExecutionContext::CallbacksEnabled::Yes }; // To clone a body body, run these steps: // 1. Let « out1, out2 » be the result of teeing body’s stream. auto [out1, out2] = m_stream->tee(&realm).release_value_but_fixme_should_propagate_errors(); // 2. Set body’s stream to out1. m_stream = out1; // 3. Return a body whose stream is out2 and other members are copied from body. return Body::create(realm.vm(), *out2, m_source, m_length); } // https://fetch.spec.whatwg.org/#body-fully-read void Body::fully_read(JS::Realm& realm, Web::Fetch::Infrastructure::Body::ProcessBodyCallback process_body, Web::Fetch::Infrastructure::Body::ProcessBodyErrorCallback process_body_error, TaskDestination task_destination) const { HTML::TemporaryExecutionContext execution_context { realm, HTML::TemporaryExecutionContext::CallbacksEnabled::Yes }; // 1. If taskDestination is null, then set taskDestination to the result of starting a new parallel queue. if (task_destination.has()) task_destination = HTML::ParallelQueue::create(); // 2. Let successSteps given a byte sequence bytes be to queue a fetch task to run processBody given bytes, with taskDestination. auto success_steps = [&realm, process_body, task_destination](ByteBuffer bytes) { queue_fetch_task(task_destination, GC::create_function(realm.heap(), [process_body, bytes = move(bytes)]() mutable { process_body->function()(move(bytes)); })); }; // 3. Let errorSteps optionally given an exception exception be to queue a fetch task to run processBodyError given // exception, with taskDestination. auto error_steps = [&realm, process_body_error, task_destination](JS::Value exception) { queue_fetch_task(task_destination, GC::create_function(realm.heap(), [process_body_error, exception]() { process_body_error->function()(exception); })); }; // 4. Let reader be the result of getting a reader for body’s stream. If that threw an exception, then run errorSteps // with that exception and return. auto reader = m_stream->get_a_reader(); if (reader.is_exception()) { auto throw_completion = Bindings::exception_to_throw_completion(realm.vm(), reader.release_error()); error_steps(throw_completion.release_value()); return; } // 5. Read all bytes from reader, given successSteps and errorSteps. reader.value()->read_all_bytes(GC::create_function(realm.heap(), move(success_steps)), GC::create_function(realm.heap(), move(error_steps))); } // https://fetch.spec.whatwg.org/#body-incrementally-read void Body::incrementally_read(ProcessBodyChunkCallback process_body_chunk, ProcessEndOfBodyCallback process_end_of_body, ProcessBodyErrorCallback process_body_error, TaskDestination task_destination) { HTML::TemporaryExecutionContext const execution_context { m_stream->realm(), HTML::TemporaryExecutionContext::CallbacksEnabled::Yes }; // 1. If taskDestination is null, then set taskDestination to the result of starting a new parallel queue. if (task_destination.has()) task_destination = HTML::ParallelQueue::create(); // 2. Let reader be the result of getting a reader for body’s stream. // NOTE: This operation will not throw an exception. auto reader = MUST(m_stream->get_a_reader()); // 3. Perform the incrementally-read loop given reader, taskDestination, processBodyChunk, processEndOfBody, and processBodyError. VERIFY(!task_destination.has()); incrementally_read_loop(reader, task_destination.get>(), process_body_chunk, process_end_of_body, process_body_error); } // https://fetch.spec.whatwg.org/#incrementally-read-loop void Body::incrementally_read_loop(Streams::ReadableStreamDefaultReader& reader, TaskDestination task_destination, ProcessBodyChunkCallback process_body_chunk, ProcessEndOfBodyCallback process_end_of_body, ProcessBodyErrorCallback process_body_error) { auto& realm = reader.realm(); // 1. Let readRequest be the following read request: auto read_request = realm.create(*this, reader, task_destination, process_body_chunk, process_end_of_body, process_body_error); // 2. Read a chunk from reader given readRequest. reader.read_a_chunk(read_request); } // https://fetch.spec.whatwg.org/#byte-sequence-as-a-body GC::Ref byte_sequence_as_body(JS::Realm& realm, ReadonlyBytes bytes) { // To get a byte sequence bytes as a body, return the body of the result of safely extracting bytes. auto [body, _] = safely_extract_body(realm, bytes); return body; } }