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-rw-r--r--src/ByteBuffer.cpp841
1 files changed, 841 insertions, 0 deletions
diff --git a/src/ByteBuffer.cpp b/src/ByteBuffer.cpp
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--- /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);
+}
+
+
+
+
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