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author | Mattes D <github@xoft.cz> | 2013-11-27 09:23:17 +0100 |
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committer | Mattes D <github@xoft.cz> | 2013-11-27 09:23:17 +0100 |
commit | 49760db89d94ede5d123d927141a6cd60dbaaf07 (patch) | |
tree | 6c6cf99e4cf3128311a93cd187947b502f3732a0 /src/ByteBuffer.cpp | |
parent | cWorld::SpawnExperienceOrb() now returns the entity ID of the spawned orb. (diff) | |
parent | Fixed VC2008 compilation, normalized include paths. (diff) | |
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Diffstat (limited to 'src/ByteBuffer.cpp')
-rw-r--r-- | src/ByteBuffer.cpp | 841 |
1 files changed, 841 insertions, 0 deletions
diff --git a/src/ByteBuffer.cpp b/src/ByteBuffer.cpp new file mode 100644 index 000000000..8f2b76c1f --- /dev/null +++ b/src/ByteBuffer.cpp @@ -0,0 +1,841 @@ + +// ByteBuffer.cpp + +// Implements the cByteBuffer class representing a ringbuffer of bytes + +#include "Globals.h" + +#include "ByteBuffer.h" +#include "Endianness.h" +#include "OSSupport/IsThread.h" + + + + + +// Try to determine endianness: +#if ( \ + defined(__i386__) || defined(__alpha__) || \ + defined(__ia64) || defined(__ia64__) || \ + defined(_M_IX86) || defined(_M_IA64) || \ + defined(_M_ALPHA) || defined(__amd64) || \ + defined(__amd64__) || defined(_M_AMD64) || \ + defined(__x86_64) || defined(__x86_64__) || \ + defined(_M_X64) || defined(__bfin__) || \ + defined(__ARMEL__) || \ + (defined(_WIN32) && defined(__ARM__) && defined(_MSC_VER)) \ +) + #define IS_LITTLE_ENDIAN +#elif defined (__ARMEB__) + #define IS_BIG_ENDIAN +#else + #error Cannot determine endianness of this platform +#endif + +// If a string sent over the protocol is larger than this, a warning is emitted to the console +#define MAX_STRING_SIZE (512 KiB) + +#define NEEDBYTES(Num) if (!CanReadBytes(Num)) return false; // Check if at least Num bytes can be read from the buffer, return false if not +#define PUTBYTES(Num) if (!CanWriteBytes(Num)) return false; // Check if at least Num bytes can be written to the buffer, return false if not + + + + + +#if 0 + +/// Self-test of the VarInt-reading and writing code +class cByteBufferSelfTest +{ +public: + cByteBufferSelfTest(void) + { + TestRead(); + TestWrite(); + } + + void TestRead(void) + { + cByteBuffer buf(50); + buf.Write("\x05\xac\x02\x00", 4); + UInt32 v1; + ASSERT(buf.ReadVarInt(v1) && (v1 == 5)); + UInt32 v2; + ASSERT(buf.ReadVarInt(v2) && (v2 == 300)); + UInt32 v3; + ASSERT(buf.ReadVarInt(v3) && (v3 == 0)); + } + + void TestWrite(void) + { + cByteBuffer buf(50); + buf.WriteVarInt(5); + buf.WriteVarInt(300); + buf.WriteVarInt(0); + AString All; + buf.ReadAll(All); + ASSERT(All.size() == 4); + ASSERT(memcmp(All.data(), "\x05\xac\x02\x00", All.size()) == 0); + } +} g_ByteBufferTest; + +#endif + + + + + +#ifdef _DEBUG + +/// Simple RAII class that uses one internal unsigned long for checking if two threads are using an object simultanously +class cSingleThreadAccessChecker +{ +public: + cSingleThreadAccessChecker(unsigned long * a_ThreadID) : + m_ThreadID(a_ThreadID) + { + ASSERT((*a_ThreadID == 0) || (*a_ThreadID == cIsThread::GetCurrentID())); + } + + ~cSingleThreadAccessChecker() + { + *m_ThreadID = 0; + } + +protected: + unsigned long * m_ThreadID; +} ; + +#define CHECK_THREAD cSingleThreadAccessChecker Checker(const_cast<unsigned long *>(&m_ThreadID)) + +#else + #define CHECK_THREAD +#endif + + + + + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +// cByteBuffer: + +cByteBuffer::cByteBuffer(int a_BufferSize) : + m_Buffer(new char[a_BufferSize + 1]), + m_BufferSize(a_BufferSize + 1), + #ifdef _DEBUG + m_ThreadID(0), + #endif // _DEBUG + m_DataStart(0), + m_WritePos(0), + m_ReadPos(0) +{ + // Allocating one byte more than the buffer size requested, so that we can distinguish between + // completely-full and completely-empty states +} + + + + + +cByteBuffer::~cByteBuffer() +{ + CheckValid(); + delete[] m_Buffer; +} + + + + + +bool cByteBuffer::Write(const char * a_Bytes, int a_Count) +{ + CHECK_THREAD; + CheckValid(); + + // Store the current free space for a check after writing: + int CurFreeSpace = GetFreeSpace(); + int CurReadableSpace = GetReadableSpace(); + int WrittenBytes = 0; + + if (GetFreeSpace() < a_Count) + { + return false; + } + int TillEnd = m_BufferSize - m_WritePos; + if (TillEnd <= a_Count) + { + // Need to wrap around the ringbuffer end + if (TillEnd > 0) + { + memcpy(m_Buffer + m_WritePos, a_Bytes, TillEnd); + a_Bytes += TillEnd; + a_Count -= TillEnd; + WrittenBytes = TillEnd; + } + m_WritePos = 0; + } + + // We're guaranteed that we'll fit in a single write op + if (a_Count > 0) + { + memcpy(m_Buffer + m_WritePos, a_Bytes, a_Count); + m_WritePos += a_Count; + WrittenBytes += a_Count; + } + + ASSERT(GetFreeSpace() == CurFreeSpace - WrittenBytes); + ASSERT(GetReadableSpace() == CurReadableSpace + WrittenBytes); + return true; +} + + + + + +int cByteBuffer::GetFreeSpace(void) const +{ + CHECK_THREAD; + CheckValid(); + if (m_WritePos >= m_DataStart) + { + // Wrap around the buffer end: + return m_BufferSize - m_WritePos + m_DataStart - 1; + } + // Single free space partition: + return m_DataStart - m_WritePos - 1; +} + + + + + +/// Returns the number of bytes that are currently in the ringbuffer. Note GetReadableBytes() +int cByteBuffer::GetUsedSpace(void) const +{ + CHECK_THREAD; + CheckValid(); + return m_BufferSize - GetFreeSpace() - 1; +} + + + + + +/// 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 cByteBuffer::GetReadableSpace(void) const +{ + CHECK_THREAD; + CheckValid(); + if (m_ReadPos > m_WritePos) + { + // Wrap around the buffer end: + return m_BufferSize - m_ReadPos + m_WritePos; + } + // Single readable space partition: + return m_WritePos - m_ReadPos ; +} + + + + + +bool cByteBuffer::CanReadBytes(int a_Count) const +{ + CHECK_THREAD; + CheckValid(); + return (a_Count <= GetReadableSpace()); +} + + + + + +bool cByteBuffer::CanWriteBytes(int a_Count) const +{ + CHECK_THREAD; + CheckValid(); + return (a_Count <= GetFreeSpace()); +} + + + + + +bool cByteBuffer::ReadChar(char & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(1); + ReadBuf(&a_Value, 1); + return true; +} + + + + + +bool cByteBuffer::ReadByte(unsigned char & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(1); + ReadBuf(&a_Value, 1); + return true; +} + + + + + +bool cByteBuffer::ReadBEShort(short & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(2); + ReadBuf(&a_Value, 2); + a_Value = ntohs(a_Value); + return true; +} + + + + + +bool cByteBuffer::ReadBEInt(int & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(4); + ReadBuf(&a_Value, 4); + a_Value = ntohl(a_Value); + return true; +} + + + + + +bool cByteBuffer::ReadBEInt64(Int64 & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(8); + ReadBuf(&a_Value, 8); + a_Value = NetworkToHostLong8(&a_Value); + return true; +} + + + + + +bool cByteBuffer::ReadBEFloat(float & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(4); + ReadBuf(&a_Value, 4); + a_Value = NetworkToHostFloat4(&a_Value); + return true; +} + + + + + +bool cByteBuffer::ReadBEDouble(double & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(8); + ReadBuf(&a_Value, 8); + a_Value = NetworkToHostDouble8(&a_Value); + return true; +} + + + + + +bool cByteBuffer::ReadBool(bool & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(1); + char Value = 0; + ReadBuf(&Value, 1); + a_Value = (Value != 0); + return true; +} + + + + + +bool cByteBuffer::ReadBEUTF16String16(AString & a_Value) +{ + CHECK_THREAD; + CheckValid(); + short Length; + if (!ReadBEShort(Length)) + { + return false; + } + if (Length < 0) + { + ASSERT(!"Negative string length? Are you sure?"); + return true; + } + return ReadUTF16String(a_Value, Length); +} + + + + + +bool cByteBuffer::ReadVarInt(UInt32 & a_Value) +{ + CHECK_THREAD; + CheckValid(); + UInt32 Value = 0; + int Shift = 0; + unsigned char b = 0; + do + { + NEEDBYTES(1); + ReadBuf(&b, 1); + Value = Value | (((Int64)(b & 0x7f)) << Shift); + Shift += 7; + } while ((b & 0x80) != 0); + a_Value = Value; + return true; +} + + + + + +bool cByteBuffer::ReadVarUTF8String(AString & a_Value) +{ + CHECK_THREAD; + CheckValid(); + UInt32 Size = 0; + if (!ReadVarInt(Size)) + { + return false; + } + if (Size > MAX_STRING_SIZE) + { + LOGWARNING("%s: String too large: %llu (%llu KiB)", __FUNCTION__, Size, Size / 1024); + } + return ReadString(a_Value, (int)Size); +} + + + + + +bool cByteBuffer::ReadLEInt(int & a_Value) +{ + CHECK_THREAD; + CheckValid(); + NEEDBYTES(4); + ReadBuf(&a_Value, 4); + + #ifdef IS_BIG_ENDIAN + // Convert: + a_Value = ((a_Value >> 24) & 0xff) | ((a_Value >> 16) & 0xff00) | ((a_Value >> 8) & 0xff0000) | (a_Value & 0xff000000); + #endif + + return true; +} + + + + + +bool cByteBuffer::WriteChar(char a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(1); + return WriteBuf(&a_Value, 1); +} + + + + + +bool cByteBuffer::WriteByte(unsigned char a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(1); + return WriteBuf(&a_Value, 1); +} + + + + + +bool cByteBuffer::WriteBEShort(short a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(2); + short Converted = htons(a_Value); + return WriteBuf(&Converted, 2); +} + + + + + +bool cByteBuffer::WriteBEInt(int a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(4); + int Converted = HostToNetwork4(&a_Value); + return WriteBuf(&Converted, 4); +} + + + + + +bool cByteBuffer::WriteBEInt64(Int64 a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(8); + Int64 Converted = HostToNetwork8(&a_Value); + return WriteBuf(&Converted, 8); +} + + + + + +bool cByteBuffer::WriteBEFloat(float a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(4); + int Converted = HostToNetwork4(&a_Value); + return WriteBuf(&Converted, 4); +} + + + + + +bool cByteBuffer::WriteBEDouble(double a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(8); + Int64 Converted = HostToNetwork8(&a_Value); + return WriteBuf(&Converted, 8); +} + + + + + + +bool cByteBuffer::WriteBool(bool a_Value) +{ + CHECK_THREAD; + CheckValid(); + return WriteChar(a_Value ? 1 : 0); +} + + + + + +bool cByteBuffer::WriteBEUTF16String16(const AString & a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(2); + AString UTF16BE; + UTF8ToRawBEUTF16(a_Value.data(), a_Value.size(), UTF16BE); + WriteBEShort((short)(UTF16BE.size() / 2)); + PUTBYTES(UTF16BE.size()); + WriteBuf(UTF16BE.data(), UTF16BE.size()); + return true; +} + + + + + +bool cByteBuffer::WriteVarInt(UInt32 a_Value) +{ + CHECK_THREAD; + CheckValid(); + + // A 32-bit integer can be encoded by at most 5 bytes: + unsigned char b[5]; + int idx = 0; + do + { + b[idx] = (a_Value & 0x7f) | ((a_Value > 0x7f) ? 0x80 : 0x00); + a_Value = a_Value >> 7; + idx++; + } while (a_Value > 0); + + return WriteBuf(b, idx); +} + + + + +bool cByteBuffer::WriteVarUTF8String(const AString & a_Value) +{ + CHECK_THREAD; + CheckValid(); + PUTBYTES(a_Value.size() + 1); // This is a lower-bound on the bytes that will be actually written. Fail early. + bool res = WriteVarInt(a_Value.size()); + if (!res) + { + return false; + } + return WriteBuf(a_Value.data(), a_Value.size()); +} + + + + + +bool cByteBuffer::WriteLEInt(int a_Value) +{ + CHECK_THREAD; + CheckValid(); + #ifdef IS_LITTLE_ENDIAN + return WriteBuf((const char *)&a_Value, 4); + #else + int Value = ((a_Value >> 24) & 0xff) | ((a_Value >> 16) & 0xff00) | ((a_Value >> 8) & 0xff0000) | (a_Value & 0xff000000); + return WriteBuf((const char *)&Value, 4); + #endif +} + + + + + +bool cByteBuffer::ReadBuf(void * a_Buffer, int a_Count) +{ + CHECK_THREAD; + CheckValid(); + ASSERT(a_Count >= 0); + NEEDBYTES(a_Count); + char * Dst = (char *)a_Buffer; // So that we can do byte math + int BytesToEndOfBuffer = m_BufferSize - m_ReadPos; + ASSERT(BytesToEndOfBuffer >= 0); // Sanity check + if (BytesToEndOfBuffer <= a_Count) + { + // Reading across the ringbuffer end, read the first part and adjust parameters: + if (BytesToEndOfBuffer > 0) + { + memcpy(Dst, m_Buffer + m_ReadPos, BytesToEndOfBuffer); + Dst += BytesToEndOfBuffer; + a_Count -= BytesToEndOfBuffer; + } + m_ReadPos = 0; + } + + // Read the rest of the bytes in a single read (guaranteed to fit): + if (a_Count > 0) + { + memcpy(Dst, m_Buffer + m_ReadPos, a_Count); + m_ReadPos += a_Count; + } + return true; +} + + + + + +bool cByteBuffer::WriteBuf(const void * a_Buffer, int a_Count) +{ + CHECK_THREAD; + CheckValid(); + ASSERT(a_Count >= 0); + PUTBYTES(a_Count); + char * Src = (char *)a_Buffer; // So that we can do byte math + int BytesToEndOfBuffer = m_BufferSize - m_WritePos; + if (BytesToEndOfBuffer <= a_Count) + { + // Reading across the ringbuffer end, read the first part and adjust parameters: + memcpy(m_Buffer + m_WritePos, Src, BytesToEndOfBuffer); + Src += BytesToEndOfBuffer; + a_Count -= BytesToEndOfBuffer; + m_WritePos = 0; + } + + // Read the rest of the bytes in a single read (guaranteed to fit): + if (a_Count > 0) + { + memcpy(m_Buffer + m_WritePos, Src, a_Count); + m_WritePos += a_Count; + } + return true; +} + + + + + +bool cByteBuffer::ReadString(AString & a_String, int a_Count) +{ + CHECK_THREAD; + CheckValid(); + ASSERT(a_Count >= 0); + NEEDBYTES(a_Count); + a_String.clear(); + a_String.reserve(a_Count); + int BytesToEndOfBuffer = m_BufferSize - m_ReadPos; + ASSERT(BytesToEndOfBuffer >= 0); // Sanity check + if (BytesToEndOfBuffer <= a_Count) + { + // Reading across the ringbuffer end, read the first part and adjust parameters: + if (BytesToEndOfBuffer > 0) + { + a_String.assign(m_Buffer + m_ReadPos, BytesToEndOfBuffer); + a_Count -= BytesToEndOfBuffer; + } + m_ReadPos = 0; + } + + // Read the rest of the bytes in a single read (guaranteed to fit): + if (a_Count > 0) + { + a_String.append(m_Buffer + m_ReadPos, a_Count); + m_ReadPos += a_Count; + } + return true; +} + + + + + +bool cByteBuffer::ReadUTF16String(AString & a_String, int a_NumChars) +{ + // Reads 2 * a_NumChars bytes and interprets it as a UTF16 string, converting it into UTF8 string a_String + CHECK_THREAD; + CheckValid(); + ASSERT(a_NumChars >= 0); + AString RawData; + if (!ReadString(RawData, a_NumChars * 2)) + { + return false; + } + RawBEToUTF8((short *)(RawData.data()), a_NumChars, a_String); + return true; +} + + + + + +bool cByteBuffer::SkipRead(int a_Count) +{ + CHECK_THREAD; + CheckValid(); + ASSERT(a_Count >= 0); + if (!CanReadBytes(a_Count)) + { + return false; + } + AdvanceReadPos(a_Count); + return true; +} + + + + + +void cByteBuffer::ReadAll(AString & a_Data) +{ + CHECK_THREAD; + CheckValid(); + ReadString(a_Data, GetReadableSpace()); +} + + + + + +void cByteBuffer::CommitRead(void) +{ + CHECK_THREAD; + CheckValid(); + m_DataStart = m_ReadPos; +} + + + + + +void cByteBuffer::ResetRead(void) +{ + CHECK_THREAD; + CheckValid(); + m_ReadPos = m_DataStart; +} + + + + + +void cByteBuffer::ReadAgain(AString & a_Out) +{ + // Return the data between m_DataStart and m_ReadPos (the data that has been read but not committed) + // Used by ProtoProxy to repeat communication twice, once for parsing and the other time for the remote party + CHECK_THREAD; + CheckValid(); + int DataStart = m_DataStart; + if (m_ReadPos < m_DataStart) + { + // Across the ringbuffer end, read the first part and adjust next part's start: + a_Out.append(m_Buffer + m_DataStart, m_BufferSize - m_DataStart); + DataStart = 0; + } + a_Out.append(m_Buffer + DataStart, m_ReadPos - DataStart); +} + + + + + +void cByteBuffer::AdvanceReadPos(int a_Count) +{ + CHECK_THREAD; + CheckValid(); + m_ReadPos += a_Count; + if (m_ReadPos > m_BufferSize) + { + m_ReadPos -= m_BufferSize; + } +} + + + + + +void cByteBuffer::CheckValid(void) const +{ + ASSERT(m_ReadPos >= 0); + ASSERT(m_ReadPos < m_BufferSize); + ASSERT(m_WritePos >= 0); + ASSERT(m_WritePos < m_BufferSize); +} + + + + |