Simplified FIFO implementation

Fixed a memoryleak in Netstring class

base/fifo.cpp

@@ -5,7 +5,8 @@ using namespace icinga;
 FIFO::FIFO(void)
 {
 	m_Buffer = NULL;
-	m_BufferSize = 0;
+	m_DataSize = 0;
+	m_AllocSize = 0;
 	m_Offset = 0;
 }
 
@@ -14,44 +15,29 @@ FIFO::~FIFO(void)
 	Memory::Free(m_Buffer);
 }
 
-char *FIFO::ResizeBuffer(char *buffer, size_t oldSize, size_t newSize)
+void FIFO::ResizeBuffer(size_t newSize)
 {
-	if (oldSize != 0)
-		oldSize += FIFO::BlockSize - (oldSize % FIFO::BlockSize);
+	if (m_AllocSize >= newSize)
+		return;
 
-	size_t ceilNewSize = newSize + FIFO::BlockSize - (newSize % FIFO::BlockSize);
-	size_t oldBlocks = oldSize / FIFO::BlockSize;
-	size_t newBlocks = ceilNewSize / FIFO::BlockSize;
+	newSize = (newSize / FIFO::BlockSize + 1) * FIFO::BlockSize;
 
-	if (oldBlocks == newBlocks)
-		return buffer;
-
-	if (newSize == 0) {
-		Memory::Free(buffer);
-		return NULL;
-	} else {
-		return (char *)Memory::Reallocate(buffer, newBlocks * FIFO::BlockSize);
-	}
+	m_Buffer = (char *)Memory::Reallocate(m_Buffer, newSize);
+	m_AllocSize = newSize;
 }
 
 void FIFO::Optimize(void)
 {
-	char *newBuffer;
+	//char *newBuffer;
 
-	if (m_Offset == 0 || m_Offset < m_BufferSize / 5)
-		return;
-
-	if (m_BufferSize - m_Offset == 0) {
-		free(m_Buffer);
-
-		m_Buffer = 0;
-		m_BufferSize = 0;
+	if (m_DataSize < m_Offset) {
+		memcpy(m_Buffer, m_Buffer + m_Offset, m_DataSize);
 		m_Offset = 0;
 
 		return;
 	}
 
-	newBuffer = (char *)ResizeBuffer(NULL, 0, m_BufferSize - m_Offset);
+	/*newBuffer = (char *)ResizeBuffer(NULL, 0, m_BufferSize - m_Offset);
 
 	if (newBuffer == NULL)
 		return;
@@ -61,12 +47,12 @@ void FIFO::Optimize(void)
 	free(m_Buffer);
 	m_Buffer = newBuffer;
 	m_BufferSize -= m_Offset;
-	m_Offset = 0;
+	m_Offset = 0;*/
 }
 
 size_t FIFO::GetSize(void) const
 {
-	return m_BufferSize - m_Offset;
+	return m_DataSize;
 }
 
 const void *FIFO::GetReadBuffer(void) const
@@ -76,11 +62,12 @@ const void *FIFO::GetReadBuffer(void) const
 
 size_t FIFO::Read(void *buffer, size_t count)
 {
-	count = (count <= m_BufferSize) ? count : m_BufferSize;
+	count = (count <= m_DataSize) ? count : m_DataSize;
 
 	if (buffer != NULL)
 		memcpy(buffer, m_Buffer + m_Offset, count);
 
+	m_DataSize -= count;
 	m_Offset += count;
 
 	Optimize();
@@ -90,16 +77,9 @@ size_t FIFO::Read(void *buffer, size_t count)
 
 void *FIFO::GetWriteBuffer(size_t count)
 {
-	char *new_buffer;
+	ResizeBuffer(m_Offset + m_DataSize + count);
 
-	new_buffer = ResizeBuffer(m_Buffer, m_BufferSize, m_BufferSize + count);
-
-	if (new_buffer == NULL)
-		throw exception(/*"Out of memory."*/);
-
-	m_Buffer = new_buffer;
-
-	return new_buffer + m_Offset + m_BufferSize;
+	return m_Buffer + m_Offset + m_DataSize;
 }
 
 size_t FIFO::Write(const void *buffer, size_t count)
@@ -109,7 +89,7 @@ size_t FIFO::Write(const void *buffer, size_t count)
 		memcpy(target_buffer, buffer, count);
 	}
 
-	m_BufferSize += count;
+	m_DataSize += count;
 
 	return count;
 }

base/fifo.h

@@ -8,10 +8,11 @@ class FIFO : public Object
 {
 private:
 	char *m_Buffer;
-	size_t m_BufferSize;
+	size_t m_DataSize;
+	size_t m_AllocSize;
 	size_t m_Offset;
 
-	char *ResizeBuffer(char *buffer, size_t oldSize, size_t newSize);
+	void ResizeBuffer(size_t newSize);
 	void Optimize(void);
 
 public:

jsonrpc/netstring.cpp

@@ -66,5 +66,7 @@ void Netstring::WriteJSONToFIFO(FIFO::RefType fifo, cJSON *object)
 
 	fifo->Write(strLength, strlen(strLength));
 	fifo->Write(json, len);
+	free(json);
+
 	fifo->Write(",", 1);
 }