Lift generic functionality from QuicDataReader/QuicDataWriter into Quiche
The QUIC-specific functions stay in QuicDataReader/QuicDataWriter. Generally useful functions are moved into QuicheDataReader/QuicheDataWriter.
gfe-relnote: n/a, no functional change
PiperOrigin-RevId: 288584295
Change-Id: I53b102f56f43019a89db0aa624898ed44bb6ec11
diff --git a/common/quiche_data_writer.h b/common/quiche_data_writer.h
new file mode 100644
index 0000000..8df1f90
--- /dev/null
+++ b/common/quiche_data_writer.h
@@ -0,0 +1,110 @@
+// Copyright (c) 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef QUICHE_COMMON_QUICHE_DATA_WRITER_H_
+#define QUICHE_COMMON_QUICHE_DATA_WRITER_H_
+
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+
+#include "net/third_party/quiche/src/common/platform/api/quiche_endian.h"
+#include "net/third_party/quiche/src/common/platform/api/quiche_export.h"
+#include "net/third_party/quiche/src/common/platform/api/quiche_string_piece.h"
+
+namespace quiche {
+
+// This class provides facilities for packing binary data.
+//
+// The QuicheDataWriter supports appending primitive values (int, string, etc)
+// to a frame instance. The internal memory buffer is exposed as the "data"
+// of the QuicheDataWriter.
+class QUICHE_EXPORT_PRIVATE QuicheDataWriter {
+ public:
+ // Creates a QuicheDataWriter where |buffer| is not owned
+ // using NETWORK_BYTE_ORDER endianness.
+ QuicheDataWriter(size_t size, char* buffer);
+ // Creates a QuicheDataWriter where |buffer| is not owned
+ // using the specified endianness.
+ QuicheDataWriter(size_t size, char* buffer, quiche::Endianness endianness);
+ QuicheDataWriter(const QuicheDataWriter&) = delete;
+ QuicheDataWriter& operator=(const QuicheDataWriter&) = delete;
+
+ ~QuicheDataWriter();
+
+ // Returns the size of the QuicheDataWriter's data.
+ size_t length() const { return length_; }
+
+ // Retrieves the buffer from the QuicheDataWriter without changing ownership.
+ char* data();
+
+ // Methods for adding to the payload. These values are appended to the end
+ // of the QuicheDataWriter payload.
+
+ // Writes 8/16/32/64-bit unsigned integers.
+ bool WriteUInt8(uint8_t value);
+ bool WriteUInt16(uint16_t value);
+ bool WriteUInt32(uint32_t value);
+ bool WriteUInt64(uint64_t value);
+
+ // Writes least significant |num_bytes| of a 64-bit unsigned integer in the
+ // correct byte order.
+ bool WriteBytesToUInt64(size_t num_bytes, uint64_t value);
+
+ bool WriteStringPiece(quiche::QuicheStringPiece val);
+ bool WriteStringPiece16(quiche::QuicheStringPiece val);
+ bool WriteBytes(const void* data, size_t data_len);
+ bool WriteRepeatedByte(uint8_t byte, size_t count);
+ // Fills the remaining buffer with null characters.
+ void WritePadding();
+ // Write padding of |count| bytes.
+ bool WritePaddingBytes(size_t count);
+
+ // Write tag as a 32-bit unsigned integer to the payload. As tags are already
+ // converted to big endian (e.g., CHLO is 'C','H','L','O') in memory by TAG or
+ // MakeQuicTag and tags are written in byte order, so tags on the wire are
+ // in big endian.
+ bool WriteTag(uint32_t tag);
+
+ // Advance the writer's position for writing by |length| bytes without writing
+ // anything. This method only makes sense to be used on a buffer that has
+ // already been written to (and is having certain parts rewritten).
+ bool Seek(size_t length);
+
+ size_t capacity() const { return capacity_; }
+
+ size_t remaining() const { return capacity_ - length_; }
+
+ std::string DebugString() const;
+
+ protected:
+ // Returns the location that the data should be written at, or nullptr if
+ // there is not enough room. Call EndWrite with the returned offset and the
+ // given length to pad out for the next write.
+ char* BeginWrite(size_t length);
+
+ quiche::Endianness endianness() const { return endianness_; }
+
+ char* buffer() const { return buffer_; }
+
+ void IncreaseLength(size_t delta) {
+ DCHECK_LE(length_, std::numeric_limits<size_t>::max() - delta);
+ DCHECK_LE(length_, capacity_ - delta);
+ length_ += delta;
+ }
+
+ private:
+ // TODO(fkastenholz, b/73004262) change buffer_, et al, to be uint8_t, not
+ // char.
+ char* buffer_;
+ size_t capacity_; // Allocation size of payload (or -1 if buffer is const).
+ size_t length_; // Current length of the buffer.
+
+ // The endianness to write integers and floating numbers.
+ quiche::Endianness endianness_;
+};
+
+} // namespace quiche
+
+#endif // QUICHE_COMMON_QUICHE_DATA_WRITER_H_
