Index: net/base/big_endian.h |
diff --git a/net/base/big_endian.h b/net/base/big_endian.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..0786f62f14579c00d37d2b2e7f60bbff197bbf2f |
--- /dev/null |
+++ b/net/base/big_endian.h |
@@ -0,0 +1,107 @@ |
+// Copyright (c) 2011 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_BASE_BIG_ENDIAN_H_ |
+#define NET_BASE_BIG_ENDIAN_H_ |
+#pragma once |
+ |
+#include "base/basictypes.h" |
+#include "net/base/net_export.h" |
+ |
+namespace base { |
+class StringPiece; |
+} |
+ |
+namespace net { |
+ |
+// Read an integer (signed or unsigned) from |buf| in Big Endian order. |
+// Note: this loop is unrolled with -O1 and above. |
+// NOTE(szym): glibc dns-canon.c and SpdyFrameBuilder use |
+// ntohs(*(uint16_t*)ptr) which is potentially unaligned. |
+// This would cause SIGBUS on ARMv5 or earlier and ARMv6-M. |
+template<typename T> |
+inline void ReadBigEndian(const char buf[], T* out) { |
+ *out = buf[0]; |
+ for (size_t i = 1; i < sizeof(T); ++i) { |
+ *out <<= 8; |
+ // Must cast to uint8 to avoid clobbering by sign extension. |
+ *out |= static_cast<uint8>(buf[i]); |
+ } |
+} |
+ |
+// Write an integer (signed or unsigned) |val| to |buf| in Big Endian order. |
+// Note: this loop is unrolled with -O1 and above. |
+template<typename T> |
+inline void WriteBigEndian(char buf[], T val) { |
+ for (size_t i = 0; i < sizeof(T); ++i) { |
+ buf[sizeof(T)-i-1] = static_cast<char>(val & 0xFF); |
+ val >>= 8; |
+ } |
+} |
+ |
+// Specializations to make clang happy about the (dead code) shifts above. |
+template<> |
+inline void ReadBigEndian<uint8>(const char buf[], uint8* out) { |
+ *out = buf[0]; |
+} |
+ |
+template<> |
+inline void WriteBigEndian<uint8>(char buf[], uint8 val) { |
+ buf[0] = static_cast<char>(val); |
+} |
+ |
+// Allows reading integers in network order (big endian) while iterating over |
+// an underlying buffer. All the reading functions advance the internal pointer. |
+class NET_EXPORT BigEndianReader { |
+ public: |
+ BigEndianReader(const void* buf, size_t len); |
+ |
+ const char* ptr() const { return ptr_; } |
+ int remaining() const { return end_ - ptr_; } |
+ |
+ bool Skip(size_t len); |
+ bool ReadBytes(void* out, size_t len); |
+ // Creates a StringPiece in |out| that points to the underlying buffer. |
+ bool ReadPiece(base::StringPiece* out, size_t len); |
+ bool ReadU8(uint8* value); |
+ bool ReadU16(uint16* value); |
+ bool ReadU32(uint32* value); |
+ |
+ private: |
+ // Hidden to promote type safety. |
+ template<typename T> |
+ bool Read(T* v); |
+ |
+ const char* ptr_; |
+ const char* end_; |
+}; |
+ |
+// Allows writing integers in network order (big endian) while iterating over |
+// an underlying buffer. All the writing functions advance the internal pointer. |
+class NET_EXPORT BigEndianWriter { |
+ public: |
+ BigEndianWriter(void* buf, size_t len); |
+ |
+ char* ptr() const { return ptr_; } |
+ int remaining() const { return end_ - ptr_; } |
+ |
+ bool Skip(size_t len); |
+ bool WriteBytes(const void* buf, size_t len); |
+ bool WriteU8(uint8 value); |
+ bool WriteU16(uint16 value); |
+ bool WriteU32(uint32 value); |
+ |
+ private: |
+ // Hidden to promote type safety. |
+ template<typename T> |
+ bool Write(T v); |
+ |
+ char* ptr_; |
+ char* end_; |
+}; |
+ |
+} // namespace net |
+ |
+#endif // NET_BASE_BIG_ENDIAN_H_ |
+ |