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Diffstat (limited to 'src/ByteBuffer.h')
| -rw-r--r-- | src/ByteBuffer.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/ByteBuffer.h b/src/ByteBuffer.h new file mode 100644 index 000000000..a9dd7f5ea --- /dev/null +++ b/src/ByteBuffer.h @@ -0,0 +1,139 @@ + +// ByteStream.h + +// Interfaces to the cByteBuffer class representing a ringbuffer of bytes + + + + + +#pragma once + + + + + +/** An object that can store incoming bytes and lets its clients read the bytes sequentially +The bytes are stored in a ringbuffer of constant size; if more than that size +is requested, the write operation fails. +The bytes stored can be retrieved using various ReadXXX functions; these assume that the needed +number of bytes are present in the buffer (ASSERT; for performance reasons). +The reading doesn't actually remove the bytes, it only moves the internal read ptr. +To remove the bytes, call CommitRead(). +To re-start reading from the beginning, call ResetRead(). +This class doesn't implement thread safety, the clients of this class need to provide +their own synchronization. +*/ +class cByteBuffer +{ +public: + cByteBuffer(int a_BufferSize); + ~cByteBuffer(); + + /// Writes the bytes specified to the ringbuffer. Returns true if successful, false if not + bool Write(const char * a_Bytes, int a_Count); + + /// Returns the number of bytes that can be successfully written to the ringbuffer + int GetFreeSpace(void) const; + + /// Returns the number of bytes that are currently in the ringbuffer. Note GetReadableBytes() + int GetUsedSpace(void) const; + + /// Returns the number of bytes that are currently available for reading (may be less than UsedSpace due to some data having been read already) + int GetReadableSpace(void) const; + + /// Returns true if the specified amount of bytes are available for reading + bool CanReadBytes(int a_Count) const; + + /// Returns true if the specified amount of bytes are available for writing + bool CanWriteBytes(int a_Count) const; + + // Read the specified datatype and advance the read pointer; return true if successfully read: + bool ReadChar (char & a_Value); + bool ReadByte (unsigned char & a_Value); + bool ReadBEShort (short & a_Value); + bool ReadBEInt (int & a_Value); + bool ReadBEInt64 (Int64 & a_Value); + bool ReadBEFloat (float & a_Value); + bool ReadBEDouble (double & a_Value); + bool ReadBool (bool & a_Value); + bool ReadBEUTF16String16(AString & a_Value); // string length as BE short, then string as UTF-16BE + bool ReadVarInt (UInt32 & a_Value); + bool ReadVarUTF8String (AString & a_Value); // string length as VarInt, then string as UTF-8 + bool ReadLEInt (int & a_Value); + + /// Reads VarInt, assigns it to anything that can be assigned from an UInt32 (unsigned short, char, Byte, double, ...) + template <typename T> bool ReadVarInt(T & a_Value) + { + UInt32 v; + bool res = ReadVarInt(v); + if (res) + { + a_Value = v; + } + return res; + } + + // Write the specified datatype; return true if successfully written + bool WriteChar (char a_Value); + bool WriteByte (unsigned char a_Value); + bool WriteBEShort (short a_Value); + bool WriteBEInt (int a_Value); + bool WriteBEInt64 (Int64 a_Value); + bool WriteBEFloat (float a_Value); + bool WriteBEDouble (double a_Value); + bool WriteBool (bool a_Value); + bool WriteBEUTF16String16(const AString & a_Value); // string length as BE short, then string as UTF-16BE + bool WriteVarInt (UInt32 a_Value); + bool WriteVarUTF8String (const AString & a_Value); // string length as VarInt, then string as UTF-8 + bool WriteLEInt (int a_Value); + + /// Reads a_Count bytes into a_Buffer; returns true if successful + bool ReadBuf(void * a_Buffer, int a_Count); + + /// Writes a_Count bytes into a_Buffer; returns true if successful + bool WriteBuf(const void * a_Buffer, int a_Count); + + /// Reads a_Count bytes into a_String; returns true if successful + bool ReadString(AString & a_String, int a_Count); + + /// Reads 2 * a_NumChars bytes and interprets it as a UTF16-BE string, converting it into UTF8 string a_String + bool ReadUTF16String(AString & a_String, int a_NumChars); + + /// Skips reading by a_Count bytes; returns false if not enough bytes in the ringbuffer + bool SkipRead(int a_Count); + + /// Reads all available data into a_Data + void ReadAll(AString & a_Data); + + /// Removes the bytes that have been read from the ringbuffer + void CommitRead(void); + + /// Restarts next reading operation at the start of the ringbuffer + void ResetRead(void); + + /// Re-reads the data that has been read since the last commit to the current readpos. Used by ProtoProxy to duplicate communication + void ReadAgain(AString & a_Out); + + /// Checks if the internal state is valid (read and write positions in the correct bounds) using ASSERTs + void CheckValid(void) const; + +protected: + char * m_Buffer; + int m_BufferSize; // Total size of the ringbuffer + + #ifdef _DEBUG + unsigned long m_ThreadID; // Thread that is currently accessing the object, checked via cSingleThreadAccessChecker + #endif // _DEBUG + + int m_DataStart; // Where the data starts in the ringbuffer + int m_WritePos; // Where the data ends in the ringbuffer + int m_ReadPos; // Where the next read will start in the ringbuffer + + /// Advances the m_ReadPos by a_Count bytes + void AdvanceReadPos(int a_Count); +} ; + + + + |