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
+ access the mmap function. In environments that do not support mmap
from file fd's this function will use read and normal allocated
memory.
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.
+ to allocate space from the workspace in an efficient fashion.
This source is placed in the Public Domain, do with it what you will
It was originally written by Jason Gunthorpe.
#ifndef PKGLIB_MMAP_H
#define PKGLIB_MMAP_H
-#ifdef __GNUG__
-#pragma interface "apt-pkg/mmap.h"
-#endif
#include <string>
-#include <apt-pkg/fileutl.h>
+#ifndef APT_8_CLEANER_HEADERS
+#include <apt-pkg/fileutl.h>
using std::string;
+#endif
+
+class FileFd;
/* This should be a 32 bit type, larger tyes use too much ram and smaller
types are too small. Where ever possible 'unsigned long' should be used
protected:
unsigned long Flags;
- unsigned long iSize;
+ unsigned long long iSize;
void *Base;
+ // In case mmap can not be used, we keep a dup of the file
+ // descriptor that should have been mmaped so that we can write to
+ // the file in Sync().
+ FileFd *SyncToFd;
+
bool Map(FileFd &Fd);
bool Close(bool DoSync = true);
public:
enum OpenFlags {NoImmMap = (1<<0),Public = (1<<1),ReadOnly = (1<<2),
- UnMapped = (1<<3)};
+ UnMapped = (1<<3), Moveable = (1<<4), Fallback = (1 << 5)};
// Simple accessors
inline operator void *() {return Base;};
inline void *Data() {return Base;};
- inline unsigned long Size() {return iSize;};
+ inline unsigned long long Size() {return iSize;};
+ inline void AddSize(unsigned long long const size) {iSize += size;};
+ inline bool validData() const { return Base != (void *)-1 && Base != 0; };
// File manipulators
bool Sync();
FileFd *Fd;
unsigned long WorkSpace;
+ unsigned long const GrowFactor;
+ unsigned long const Limit;
Pool *Pools;
unsigned int PoolCount;
+
+ bool Grow();
public:
// Allocation
- unsigned long RawAllocate(unsigned long Size,unsigned long Aln = 0);
+ unsigned long RawAllocate(unsigned long long Size,unsigned long Aln = 0);
unsigned long Allocate(unsigned long ItemSize);
unsigned long WriteString(const char *String,unsigned long Len = (unsigned long)-1);
- inline unsigned long WriteString(const string &S) {return WriteString(S.c_str(),S.length());};
+ inline unsigned long WriteString(const std::string &S) {return WriteString(S.c_str(),S.length());};
void UsePools(Pool &P,unsigned int Count) {Pools = &P; PoolCount = Count;};
- DynamicMMap(FileFd &F,unsigned long Flags,unsigned long WorkSpace = 2*1024*1024);
- DynamicMMap(unsigned long Flags,unsigned long WorkSpace = 2*1024*1024);
+ DynamicMMap(FileFd &F,unsigned long Flags,unsigned long const &WorkSpace = 2*1024*1024,
+ unsigned long const &Grow = 1024*1024, unsigned long const &Limit = 0);
+ DynamicMMap(unsigned long Flags,unsigned long const &WorkSpace = 2*1024*1024,
+ unsigned long const &Grow = 1024*1024, unsigned long const &Limit = 0);
virtual ~DynamicMMap();
};