From 675b4aa878f16291ce33fced48a2bc7425f635ae Mon Sep 17 00:00:00 2001
From: Alexander Harkness <bearbin@gmail.com>
Date: Sun, 24 Nov 2013 14:19:41 +0000
Subject: Moved source to src

---
 src/ByteBuffer.cpp | 787 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 787 insertions(+)
 create mode 100644 src/ByteBuffer.cpp

(limited to 'src/ByteBuffer.cpp')

diff --git a/src/ByteBuffer.cpp b/src/ByteBuffer.cpp
new file mode 100644
index 000000000..1cdd2f430
--- /dev/null
+++ b/src/ByteBuffer.cpp
@@ -0,0 +1,787 @@
+
+// ByteBuffer.cpp
+
+// Implements the cByteBuffer class representing a ringbuffer of bytes
+
+#include "Globals.h"
+
+#include "ByteBuffer.h"
+#include "Endianness.h"
+#include "OSSupport/IsThread.h"
+
+
+
+
+
+// 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::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::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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