| // Copyright (c) 2012 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 NET_SPDY_SPDY_FRAME_READER_H_ |
| #define NET_SPDY_SPDY_FRAME_READER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include "base/strings/string_piece.h" |
| #include "net/base/net_export.h" |
| |
| namespace net { |
| |
| // Used for reading SPDY frames. Though there isn't really anything terribly |
| // SPDY-specific here, it's a helper class that's useful when doing SPDY |
| // framing. |
| // |
| // To use, simply construct a SpdyFramerReader using the underlying buffer that |
| // you'd like to read fields from, then call one of the Read*() methods to |
| // actually do some reading. |
| // |
| // This class keeps an internal iterator to keep track of what's already been |
| // read and each successive Read*() call automatically increments said iterator |
| // on success. On failure, internal state of the SpdyFrameReader should not be |
| // trusted and it is up to the caller to throw away the failed instance and |
| // handle the error as appropriate. None of the Read*() methods should ever be |
| // called after failure, as they will also fail immediately. |
| class NET_EXPORT_PRIVATE SpdyFrameReader { |
| public: |
| // Caller must provide an underlying buffer to work on. |
| SpdyFrameReader(const char* data, const size_t len); |
| |
| // Empty destructor. |
| ~SpdyFrameReader() {} |
| |
| // Reads an 8-bit unsigned integer into the given output parameter. |
| // Forwards the internal iterator on success. |
| // Returns true on success, false otherwise. |
| bool ReadUInt8(uint8_t* result); |
| |
| // Reads a 16-bit unsigned integer into the given output parameter. |
| // Forwards the internal iterator on success. |
| // Returns true on success, false otherwise. |
| bool ReadUInt16(uint16_t* result); |
| |
| // Reads a 32-bit unsigned integer into the given output parameter. |
| // Forwards the internal iterator on success. |
| // Returns true on success, false otherwise. |
| bool ReadUInt32(uint32_t* result); |
| |
| // Reads a 64-bit unsigned integer into the given output parameter. |
| // Forwards the internal iterator on success. |
| // Returns true on success, false otherwise. |
| bool ReadUInt64(uint64_t* result); |
| |
| // Reads a 31-bit unsigned integer into the given output parameter. This is |
| // equivalent to ReadUInt32() above except that the highest-order bit is |
| // discarded. |
| // Forwards the internal iterator (by 4B) on success. |
| // Returns true on success, false otherwise. |
| bool ReadUInt31(uint32_t* result); |
| |
| // Reads a 24-bit unsigned integer into the given output parameter. |
| // Forwards the internal iterator (by 3B) on success. |
| // Returns true on success, false otherwise. |
| bool ReadUInt24(uint32_t* result); |
| |
| // Reads a string prefixed with 16-bit length into the given output parameter. |
| // |
| // NOTE: Does not copy but rather references strings in the underlying buffer. |
| // This should be kept in mind when handling memory management! |
| // |
| // Forwards the internal iterator on success. |
| // Returns true on success, false otherwise. |
| bool ReadStringPiece16(base::StringPiece* result); |
| |
| // Reads a string prefixed with 32-bit length into the given output parameter. |
| // |
| // NOTE: Does not copy but rather references strings in the underlying buffer. |
| // This should be kept in mind when handling memory management! |
| // |
| // Forwards the internal iterator on success. |
| // Returns true on success, false otherwise. |
| bool ReadStringPiece32(base::StringPiece* result); |
| |
| // Reads a given number of bytes into the given buffer. The buffer |
| // must be of adequate size. |
| // Forwards the internal iterator on success. |
| // Returns true on success, false otherwise. |
| bool ReadBytes(void* result, size_t size); |
| |
| // Seeks a given number of bytes into the buffer from the current offset. |
| // Equivelant to an empty read. |
| // Forwards the internal iterator. |
| // Returns true on success, false otherwise. |
| bool Seek(size_t size); |
| |
| // Rewinds this reader to the beginning of the frame. |
| void Rewind() { ofs_ = 0; } |
| |
| // Returns true if the entirety of the underlying buffer has been read via |
| // Read*() calls. |
| bool IsDoneReading() const; |
| |
| // Returns the number of bytes that have been consumed by the reader so far. |
| size_t GetBytesConsumed() const { return ofs_; } |
| |
| private: |
| // Returns true if the underlying buffer has enough room to read the given |
| // amount of bytes. |
| bool CanRead(size_t bytes) const; |
| |
| // To be called when a read fails for any reason. |
| void OnFailure(); |
| |
| // The data buffer that we're reading from. |
| const char* data_; |
| |
| // The length of the data buffer that we're reading from. |
| const size_t len_; |
| |
| // The location of the next read from our data buffer. |
| size_t ofs_; |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_SPDY_SPDY_FRAME_READER_H_ |