1 files changed, 37 insertions, 3 deletions

diff --git a/lib/base/rawfile.h b/lib/base/rawfile.h
index a1c73d6a..bb39dc6e 100644
--- a/lib/base/rawfile.h
+++ b/lib/base/rawfile.h
@@ -2,24 +2,58 @@
 #define __lib_base_rawfile_h
 
 #include <string>
+#include <lib/base/object.h>
 
-class eRawFile
+class iDataSource: public iObject
 {
 public:
+	virtual off_t lseek(off_t offset, int whence)=0;
+	virtual ssize_t read(void *buf, size_t count)=0; /* NOTE: you must be able to handle short reads! */
+	virtual off_t length()=0;
+	virtual off_t position()=0;
+	virtual int valid()=0;
+	virtual eSingleLock &getLock()=0;
+	virtual bool is_shared()=0;
+};
+
+class iDataSourcePositionRestorer
+{
+	ePtr<iDataSource> &m_source;
+	off_t m_position;
+public:
+	iDataSourcePositionRestorer(ePtr<iDataSource> &source)
+		:m_source(source)
+	{
+		if (m_source->is_shared())
+			m_position = m_source->position();
+	}
+	~iDataSourcePositionRestorer()
+	{
+		if (m_source->is_shared())
+			m_source->lseek(m_position, SEEK_SET);
+	}
+};
+
+class eRawFile: public iDataSource
+{
+	DECLARE_REF(eRawFile);
+	eSingleLock m_lock;
+public:
 	eRawFile();
 	~eRawFile();
-	
 	int open(const char *filename, int cached = 0);
 	void setfd(int fd);
 	off_t lseek(off_t offset, int whence);
 	int close();
 	ssize_t read(void *buf, size_t count); /* NOTE: you must be able to handle short reads! */
 	off_t length();
+	off_t position();
 	int valid();
+	eSingleLock &getLock();
+	bool is_shared() { return ref.count > 1; }
 private:
 	int m_fd;     /* for uncached */
 	FILE *m_file; /* for cached */
-	
 	int m_cached;
 	std::string m_basename;
 	off_t m_splitsize, m_totallength, m_current_offset, m_base_offset, m_last_offset;