Base revisions

Author: jgg
Date: 1998-07-02 02:58:12 GMT
Base revisions

1 files changed, 92 insertions, 0 deletions

diff --git a/apt-pkg/contrib/mmap.h b/apt-pkg/contrib/mmap.h
new file mode 100644
index 000000000..096304177
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+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+// $Id: mmap.h,v 1.1 1998/07/02 02:58:13 jgg Exp $
+/* ######################################################################
+   
+   MMap Class - Provides 'real' mmap or a faked mmap using read().
+
+   The purpose of this code is to provide a generic way for clients to
+   access the mmap function. In enviroments that do not support mmap
+   from file fd's this function will use read and normal allocated 
+   memory.
+   
+   Writing to a public mmap will always fully comit all changes when the 
+   class is deleted. Ie it will rewrite the file, unless it is readonly
+
+   The DynamicMMap class is used to help the on-disk data structure 
+   generators. It provides a large allocated workspace and members
+   to allocate space from the workspace in an effecient fashion.
+   
+   This source is placed in the Public Domain, do with it what you will
+   It was originally written by Jason Gunthorpe.
+   
+   ##################################################################### */
+									/*}}}*/
+// Header section: pkglib
+#ifndef PKGLIB_MMAP_H
+#define PKGLIB_MMAP_H
+
+#include <string>
+#include <pkglib/fileutl.h>
+
+class MMap
+{
+   protected:
+   
+   File &Fd;
+   unsigned long Flags;   
+   unsigned long iSize;
+   void *Base;
+
+   bool Map();
+   bool Close(bool DoClose = true);
+   
+   public:
+
+   enum OpenFlags {NoImmMap = (1<<0),Public = (1<<1),ReadOnly = (1<<2)};
+      
+   // Simple accessors
+   inline operator void *() {return Base;};
+   inline void *Data() {return Base;}; 
+   inline unsigned long Size() {return iSize;};
+   
+   // File manipulators
+   bool Sync();
+   bool Sync(unsigned long Start,unsigned long Stop);
+   
+   MMap(File &F,unsigned long Flags);
+   virtual ~MMap();
+};
+
+class DynamicMMap : public MMap
+{
+   public:
+   
+   // This is the allocation pool structure
+   struct Pool
+   {
+      unsigned long ItemSize;
+      unsigned long Start;
+      unsigned long Count;
+   };
+   
+   protected:
+   
+   unsigned long WorkSpace;
+   Pool *Pools;
+   unsigned int PoolCount;
+   
+   public:
+
+   // Allocation
+   unsigned long RawAllocate(unsigned long Size);
+   unsigned long Allocate(unsigned long ItemSize);
+   unsigned long WriteString(const char *String,unsigned long Len = 0);
+   inline unsigned long WriteString(string S) {return WriteString(S.begin(),S.size());};
+   void UsePools(Pool &P,unsigned int Count) {Pools = &P; PoolCount = Count;}; 
+   
+   DynamicMMap(File &F,unsigned long Flags,unsigned long WorkSpace = 1024*1024);
+   virtual ~DynamicMMap();
+};
+
+#endif