Added a cGZipFile class for reading GZipped files.

git-svn-id: http://mc-server.googlecode.com/svn/trunk@1196 0a769ca7-a7f5-676a-18bf-c427514a06d6

source/OSSupport/GZipFile.cpp

@@ -0,0 +1,79 @@
+
+// GZipFile.cpp
+
+// Implements the cGZipFile class representing a RAII wrapper over zlib's GZip file routines
+
+#include "Globals.h"
+#include "GZipFile.h"
+
+
+
+
+
+cGZipFile::cGZipFile(void) :
+	m_File(NULL)
+{
+}
+
+
+
+
+
+cGZipFile::~cGZipFile()
+{
+	Close();
+}
+
+
+
+
+
+bool cGZipFile::Open(const AString & a_FileName, eMode a_Mode)
+{
+	if (m_File != NULL)
+	{
+		ASSERT(!"A file is already open in this object");
+		return false;
+	}
+	m_File = gzopen(a_FileName.c_str(), (a_Mode == fmRead) ? "r" : "w");
+	return (m_File != NULL);
+}
+
+
+
+
+
+void cGZipFile::Close(void)
+{
+	if (m_File != NULL)
+	{
+		gzclose(m_File);
+		m_File = NULL;
+	}
+}
+
+
+
+
+
+int cGZipFile::ReadRestOfFile(AString & a_Contents)
+{
+	if (m_File == NULL)
+	{
+		ASSERT(!"No file has been opened");
+		return -1;
+	}
+	
+	// Since the gzip format doesn't really support getting the uncompressed length, we need to read incrementally. Yuck!
+	int NumBytesRead = 0;
+	char Buffer[64 KiB];
+	while ((NumBytesRead = gzread(m_File, Buffer, sizeof(Buffer))) > 0)
+	{
+		a_Contents.append(Buffer, NumBytesRead);
+	}
+	return NumBytesRead;
+}
+
+
+
+