henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libjingle |
| 3 | * Copyright 2004--2005, Google Inc. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright notice, |
| 9 | * this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer in the documentation |
| 12 | * and/or other materials provided with the distribution. |
| 13 | * 3. The name of the author may not be used to endorse or promote products |
| 14 | * derived from this software without specific prior written permission. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 17 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 18 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
| 19 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 20 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 22 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 23 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 24 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 25 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #ifndef TALK_BASE_BYTEBUFFER_H_ |
| 29 | #define TALK_BASE_BYTEBUFFER_H_ |
| 30 | |
| 31 | #include <string> |
| 32 | |
| 33 | #include "talk/base/basictypes.h" |
| 34 | #include "talk/base/constructormagic.h" |
| 35 | |
| 36 | namespace talk_base { |
| 37 | |
| 38 | class ByteBuffer { |
| 39 | public: |
| 40 | |
| 41 | enum ByteOrder { |
| 42 | ORDER_NETWORK = 0, // Default, use network byte order (big endian). |
| 43 | ORDER_HOST, // Use the native order of the host. |
| 44 | }; |
| 45 | |
| 46 | // |byte_order| defines order of bytes in the buffer. |
| 47 | ByteBuffer(); |
| 48 | explicit ByteBuffer(ByteOrder byte_order); |
| 49 | ByteBuffer(const char* bytes, size_t len); |
| 50 | ByteBuffer(const char* bytes, size_t len, ByteOrder byte_order); |
| 51 | |
| 52 | // Initializes buffer from a zero-terminated string. |
| 53 | explicit ByteBuffer(const char* bytes); |
| 54 | |
| 55 | ~ByteBuffer(); |
| 56 | |
| 57 | const char* Data() const { return bytes_ + start_; } |
| 58 | size_t Length() const { return end_ - start_; } |
| 59 | size_t Capacity() const { return size_ - start_; } |
| 60 | ByteOrder Order() const { return byte_order_; } |
| 61 | |
| 62 | // Read a next value from the buffer. Return false if there isn't |
| 63 | // enough data left for the specified type. |
| 64 | bool ReadUInt8(uint8* val); |
| 65 | bool ReadUInt16(uint16* val); |
| 66 | bool ReadUInt24(uint32* val); |
| 67 | bool ReadUInt32(uint32* val); |
| 68 | bool ReadUInt64(uint64* val); |
| 69 | bool ReadBytes(char* val, size_t len); |
| 70 | |
| 71 | // Appends next |len| bytes from the buffer to |val|. Returns false |
| 72 | // if there is less than |len| bytes left. |
| 73 | bool ReadString(std::string* val, size_t len); |
| 74 | |
| 75 | // Write value to the buffer. Resizes the buffer when it is |
| 76 | // neccessary. |
| 77 | void WriteUInt8(uint8 val); |
| 78 | void WriteUInt16(uint16 val); |
| 79 | void WriteUInt24(uint32 val); |
| 80 | void WriteUInt32(uint32 val); |
| 81 | void WriteUInt64(uint64 val); |
| 82 | void WriteString(const std::string& val); |
| 83 | void WriteBytes(const char* val, size_t len); |
| 84 | |
| 85 | // Reserves the given number of bytes and returns a char* that can be written |
| 86 | // into. Useful for functions that require a char* buffer and not a |
| 87 | // ByteBuffer. |
| 88 | char* ReserveWriteBuffer(size_t len); |
| 89 | |
| 90 | // Resize the buffer to the specified |size|. This invalidates any remembered |
| 91 | // seek positions. |
| 92 | void Resize(size_t size); |
| 93 | |
| 94 | // Moves current position |size| bytes forward. Returns false if |
| 95 | // there is less than |size| bytes left in the buffer. Consume doesn't |
| 96 | // permanently remove data, so remembered read positions are still valid |
| 97 | // after this call. |
| 98 | bool Consume(size_t size); |
| 99 | |
| 100 | // Clears the contents of the buffer. After this, Length() will be 0. |
| 101 | void Clear(); |
| 102 | |
| 103 | // Used with GetReadPosition/SetReadPosition. |
| 104 | class ReadPosition { |
| 105 | friend class ByteBuffer; |
| 106 | ReadPosition(size_t start, int version) |
| 107 | : start_(start), version_(version) { } |
| 108 | size_t start_; |
| 109 | int version_; |
| 110 | }; |
| 111 | |
| 112 | // Remembers the current read position for a future SetReadPosition. Any |
| 113 | // calls to Shift or Resize in the interim will invalidate the position. |
| 114 | ReadPosition GetReadPosition() const; |
| 115 | |
| 116 | // If the given position is still valid, restores that read position. |
| 117 | bool SetReadPosition(const ReadPosition &position); |
| 118 | |
| 119 | private: |
| 120 | void Construct(const char* bytes, size_t size, ByteOrder byte_order); |
| 121 | |
| 122 | char* bytes_; |
| 123 | size_t size_; |
| 124 | size_t start_; |
| 125 | size_t end_; |
| 126 | int version_; |
| 127 | ByteOrder byte_order_; |
| 128 | |
| 129 | // There are sensible ways to define these, but they aren't needed in our code |
| 130 | // base. |
| 131 | DISALLOW_COPY_AND_ASSIGN(ByteBuffer); |
| 132 | }; |
| 133 | |
| 134 | } // namespace talk_base |
| 135 | |
| 136 | #endif // TALK_BASE_BYTEBUFFER_H_ |