[apt.git] / apt-pkg / contrib / mmap.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: mmap.cc,v 1.22 2001/05/27 05:19:30 jgg Exp $
/* ######################################################################
   
   MMap Class - Provides 'real' mmap or a faked mmap using read().

   MMap cover class.

   Some broken versions of glibc2 (libc6) have a broken definition
   of mmap that accepts a char * -- all other systems (and libc5) use
   void *. We can't safely do anything here that would be portable, so
   libc6 generates warnings -- which should be errors, g++ isn't properly
   strict.
   
   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#define _BSD_SOURCE
#include <config.h>

#include <apt-pkg/mmap.h>
#include <apt-pkg/error.h>

#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>
#include <cstring>

#include <apti18n.h>
									/*}}}*/

// MMap::MMap - Constructor						/*{{{*/
// ---------------------------------------------------------------------
/* */
MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0),
                     Base(0), SyncToFd(NULL)
{
   if ((Flags & NoImmMap) != NoImmMap)
      Map(F);
}
									/*}}}*/
// MMap::MMap - Constructor						/*{{{*/
// ---------------------------------------------------------------------
/* */
MMap::MMap(unsigned long Flags) : Flags(Flags), iSize(0),
                     Base(0), SyncToFd(NULL)
{
}
									/*}}}*/
// MMap::~MMap - Destructor						/*{{{*/
// ---------------------------------------------------------------------
/* */
MMap::~MMap()
{
   Close();
}
									/*}}}*/
// MMap::Map - Perform the mapping					/*{{{*/
// ---------------------------------------------------------------------
/* */
bool MMap::Map(FileFd &Fd)
{
   iSize = Fd.Size();
   
   // Set the permissions.
   int Prot = PROT_READ;
   int Map = MAP_SHARED;
   if ((Flags & ReadOnly) != ReadOnly)
      Prot |= PROT_WRITE;
   if ((Flags & Public) != Public)
      Map = MAP_PRIVATE;
   
   if (iSize == 0)
      return _error->Error(_("Can't mmap an empty file"));
   
   // Map it.
   Base = mmap(0,iSize,Prot,Map,Fd.Fd(),0);
   if (Base == (void *)-1)
   {
      if (errno == ENODEV || errno == EINVAL)
      {
	 // The filesystem doesn't support this particular kind of mmap.
	 // So we allocate a buffer and read the whole file into it.
	 int const dupped_fd = dup(Fd.Fd());
	 if (dupped_fd == -1)
	    return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd());

	 Base = new unsigned char[iSize];
	 SyncToFd = new FileFd (dupped_fd);
	 if (!SyncToFd->Seek(0L) || !SyncToFd->Read(Base, iSize))
	    return false;
      }
      else
	 return _error->Errno("mmap",_("Couldn't make mmap of %llu bytes"),
	                      iSize);
     }

   return true;
}
									/*}}}*/
// MMap::Close - Close the map						/*{{{*/
// ---------------------------------------------------------------------
/* */
bool MMap::Close(bool DoSync)
{
   if ((Flags & UnMapped) == UnMapped || validData() == false || iSize == 0)
      return true;
   
   if (DoSync == true)
      Sync();

   if (SyncToFd != NULL)
   {
      delete[] (char *)Base;
      delete SyncToFd;
      SyncToFd = NULL;
   }
   else
   {
      if (munmap((char *)Base, iSize) != 0)
	 _error->WarningE("mmap", _("Unable to close mmap"));
   }

   iSize = 0;
   Base = 0;
   return true;
}
									/*}}}*/
// MMap::Sync - Syncronize the map with the disk			/*{{{*/
// ---------------------------------------------------------------------
/* This is done in syncronous mode - the docs indicate that this will 
   not return till all IO is complete */
bool MMap::Sync()
{   
   if ((Flags & UnMapped) == UnMapped)
      return true;
   
#ifdef _POSIX_SYNCHRONIZED_IO   
   if ((Flags & ReadOnly) != ReadOnly)
   {
      if (SyncToFd != NULL)
      {
	 if (!SyncToFd->Seek(0) || !SyncToFd->Write(Base, iSize))
	    return false;
      }
      else
      {
	 if (msync((char *)Base, iSize, MS_SYNC) < 0)
	    return _error->Errno("msync", _("Unable to synchronize mmap"));
      }
   }
#endif   
   return true;
}
									/*}}}*/
// MMap::Sync - Syncronize a section of the file to disk		/*{{{*/
// ---------------------------------------------------------------------
/* */
bool MMap::Sync(unsigned long Start,unsigned long Stop)
{
   if ((Flags & UnMapped) == UnMapped)
      return true;
   
#ifdef _POSIX_SYNCHRONIZED_IO
   unsigned long long PSize = sysconf(_SC_PAGESIZE);
   if ((Flags & ReadOnly) != ReadOnly)
   {
      if (SyncToFd != 0)
      {
	 if (!SyncToFd->Seek(0) ||
	     !SyncToFd->Write (((char *)Base)+Start, Stop-Start))
	    return false;
      }
      else
      {
	 if (msync((char *)Base+(unsigned long long)(Start/PSize)*PSize,Stop - Start,MS_SYNC) < 0)
	    return _error->Errno("msync", _("Unable to synchronize mmap"));
      }
   }
#endif   
   return true;
}
									/*}}}*/

// DynamicMMap::DynamicMMap - Constructor				/*{{{*/
// ---------------------------------------------------------------------
/* */
DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long const &Workspace,
			 unsigned long const &Grow, unsigned long const &Limit) :
		MMap(F,Flags | NoImmMap), Fd(&F), WorkSpace(Workspace),
		GrowFactor(Grow), Limit(Limit)
{
   if (_error->PendingError() == true)
      return;
   
   unsigned long long EndOfFile = Fd->Size();
   if (EndOfFile > WorkSpace)
      WorkSpace = EndOfFile;
   else if(WorkSpace > 0)
   {
      Fd->Seek(WorkSpace - 1);
      char C = 0;
      Fd->Write(&C,sizeof(C));
   }
   
   Map(F);
   iSize = EndOfFile;
}
									/*}}}*/
// DynamicMMap::DynamicMMap - Constructor for a non-file backed map	/*{{{*/
// ---------------------------------------------------------------------
/* We try here to use mmap to reserve some space - this is much more
   cooler than the fallback solution to simply allocate a char array
   and could come in handy later than we are able to grow such an mmap */
DynamicMMap::DynamicMMap(unsigned long Flags,unsigned long const &WorkSpace,
			 unsigned long const &Grow, unsigned long const &Limit) :
		MMap(Flags | NoImmMap | UnMapped), Fd(0), WorkSpace(WorkSpace),
		GrowFactor(Grow), Limit(Limit)
{
	if (_error->PendingError() == true)
		return;

	// disable Moveable if we don't grow
	if (Grow == 0)
		this->Flags &= ~Moveable;

#ifndef __linux__
	// kfreebsd doesn't have mremap, so we use the fallback
	if ((this->Flags & Moveable) == Moveable)
		this->Flags |= Fallback;
#endif

#ifdef _POSIX_MAPPED_FILES
	if ((this->Flags & Fallback) != Fallback) {
		// Set the permissions.
		int Prot = PROT_READ;
#ifdef MAP_ANONYMOUS
		int Map = MAP_PRIVATE | MAP_ANONYMOUS;
#else
		int Map = MAP_PRIVATE | MAP_ANON;
#endif
		if ((this->Flags & ReadOnly) != ReadOnly)
			Prot |= PROT_WRITE;
		if ((this->Flags & Public) == Public)
#ifdef MAP_ANONYMOUS
			Map = MAP_SHARED | MAP_ANONYMOUS;
#else
			Map = MAP_SHARED | MAP_ANON;
#endif

		// use anonymous mmap() to get the memory
		Base = (unsigned char*) mmap(0, WorkSpace, Prot, Map, -1, 0);

		if(Base == MAP_FAILED)
			_error->Errno("DynamicMMap",_("Couldn't make mmap of %lu bytes"),WorkSpace);

		iSize = 0;
		return;
	}
#endif
	// fallback to a static allocated space
	Base = new unsigned char[WorkSpace];
	memset(Base,0,WorkSpace);
	iSize = 0;
}
									/*}}}*/
// DynamicMMap::~DynamicMMap - Destructor				/*{{{*/
// ---------------------------------------------------------------------
/* We truncate the file to the size of the memory data set */
DynamicMMap::~DynamicMMap()
{
   if (Fd == 0)
   {
      if (validData() == false)
	 return;
#ifdef _POSIX_MAPPED_FILES
      munmap(Base, WorkSpace);
#else
      delete [] (unsigned char *)Base;
#endif
      return;
   }
   
   unsigned long long EndOfFile = iSize;
   iSize = WorkSpace;
   Close(false);
   if(ftruncate(Fd->Fd(),EndOfFile) < 0)
      _error->Errno("ftruncate", _("Failed to truncate file"));
}  
									/*}}}*/
// DynamicMMap::RawAllocate - Allocate a raw chunk of unaligned space	/*{{{*/
// ---------------------------------------------------------------------
/* This allocates a block of memory aligned to the given size */
unsigned long DynamicMMap::RawAllocate(unsigned long long Size,unsigned long Aln)
{
   unsigned long long Result = iSize;
   if (Aln != 0)
      Result += Aln - (iSize%Aln);

   iSize = Result + Size;

   // try to grow the buffer
   while(Result + Size > WorkSpace)
   {
      if(!Grow())
      {
	 _error->Fatal(_("Dynamic MMap ran out of room. Please increase the size "
			 "of APT::Cache-Limit. Current value: %lu. (man 5 apt.conf)"), WorkSpace);
	 return 0;
      }
   }
   return Result;
}
									/*}}}*/
// DynamicMMap::Allocate - Pooled aligned allocation			/*{{{*/
// ---------------------------------------------------------------------
/* This allocates an Item of size ItemSize so that it is aligned to its
   size in the file. */
unsigned long DynamicMMap::Allocate(unsigned long ItemSize)
{
   // Look for a matching pool entry
   Pool *I;
   Pool *Empty = 0;
   for (I = Pools; I != Pools + PoolCount; ++I)
   {
      if (I->ItemSize == 0)
	 Empty = I;
      if (I->ItemSize == ItemSize)
	 break;
   }
   // No pool is allocated, use an unallocated one
   if (I == Pools + PoolCount)
   {
      // Woops, we ran out, the calling code should allocate more.
      if (Empty == 0)
      {
	 _error->Error("Ran out of allocation pools");
	 return 0;
      }
      
      I = Empty;
      I->ItemSize = ItemSize;
      I->Count = 0;
   }

   unsigned long Result = 0;
   // Out of space, allocate some more
   if (I->Count == 0)
   {
      const unsigned long size = 20*1024;
      I->Count = size/ItemSize;
      Pool* oldPools = Pools;
      Result = RawAllocate(size,ItemSize);
      if (Pools != oldPools)
	 I += Pools - oldPools;

      // Does the allocation failed ?
      if (Result == 0 && _error->PendingError())
	 return 0;
      I->Start = Result;
   }
   else
      Result = I->Start;

   I->Count--;
   I->Start += ItemSize;
   return Result/ItemSize;
}
									/*}}}*/
// DynamicMMap::WriteString - Write a string to the file		/*{{{*/
// ---------------------------------------------------------------------
/* Strings are not aligned to anything */
unsigned long DynamicMMap::WriteString(const char *String,
				       unsigned long Len)
{
   if (Len == (unsigned long)-1)
      Len = strlen(String);

   unsigned long const Result = RawAllocate(Len+1,0);

   if (Result == 0 && _error->PendingError())
      return 0;

   memcpy((char *)Base + Result,String,Len);
   ((char *)Base)[Result + Len] = 0;
   return Result;
}
									/*}}}*/
// DynamicMMap::Grow - Grow the mmap					/*{{{*/
// ---------------------------------------------------------------------
/* This method is a wrapper around different methods to (try to) grow
   a mmap (or our char[]-fallback). Encounterable environments:
   1. Moveable + !Fallback + linux -> mremap with MREMAP_MAYMOVE
   2. Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
   3. Moveable + Fallback -> realloc
   4. !Moveable + !Fallback + linux -> mremap alone - which will fail in 99,9%
   5. !Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
   6. !Moveable + Fallback -> not possible
   [ While Moveable and Fallback stands for the equally named flags and
     "linux" indicates a linux kernel instead of a freebsd kernel. ]
   So what you can see here is, that a MMAP which want to be growable need
   to be moveable to have a real chance but that this method will at least try
   the nearly impossible 4 to grow it before it finally give up: Never say never. */
bool DynamicMMap::Grow() {
	if (Limit != 0 && WorkSpace >= Limit)
		return _error->Error(_("Unable to increase the size of the MMap as the "
		                       "limit of %lu bytes is already reached."), Limit);
	if (GrowFactor <= 0)
		return _error->Error(_("Unable to increase size of the MMap as automatic growing is disabled by user."));

	unsigned long long const newSize = WorkSpace + GrowFactor;

	if(Fd != 0) {
		Fd->Seek(newSize - 1);
		char C = 0;
		Fd->Write(&C,sizeof(C));
	}

	unsigned long const poolOffset = Pools - ((Pool*) Base);

	if ((Flags & Fallback) != Fallback) {
#if defined(_POSIX_MAPPED_FILES) && defined(__linux__)
   #ifdef MREMAP_MAYMOVE

		if ((Flags & Moveable) == Moveable)
			Base = mremap(Base, WorkSpace, newSize, MREMAP_MAYMOVE);
		else
   #endif
			Base = mremap(Base, WorkSpace, newSize, 0);

		if(Base == MAP_FAILED)
			return false;
#else
		return false;
#endif
	} else {
		if ((Flags & Moveable) != Moveable)
			return false;

		Base = realloc(Base, newSize);
		if (Base == NULL)
			return false;
	}

	Pools =(Pool*) Base + poolOffset;
	WorkSpace = newSize;
	return true;
}
									/*}}}*/
Commit	Line	Data
578bfd0a AL	1	// -- mode: cpp; mode: fold --
578bfd0a AL	2	// Description /{{{/
0db4a45b	3	// $Id: mmap.cc,v 1.22 2001/05/27 05:19:30 jgg Exp $
578bfd0a AL	4	/* ######################################################################
	5
	6	MMap Class - Provides 'real' mmap or a faked mmap using read().
	7
	8	MMap cover class.
	9
	10	Some broken versions of glibc2 (libc6) have a broken definition
	11	of mmap that accepts a char * -- all other systems (and libc5) use
	12	void *. We can't safely do anything here that would be portable, so
	13	libc6 generates warnings -- which should be errors, g++ isn't properly
	14	strict.
	15
578bfd0a AL	16	##################################################################### */
	17	/}}}/
	18	// Include Files /{{{/
	19	#define _BSD_SOURCE
ea542140 DK	20	#include <config.h>
ea542140 DK	21
094a497d AL	22	#include <apt-pkg/mmap.h>
094a497d AL	23	#include <apt-pkg/error.h>
578bfd0a AL	24
	25	#include <sys/mman.h>
	26	#include <sys/stat.h>
578bfd0a AL	27	#include <unistd.h>
578bfd0a AL	28	#include <fcntl.h>
13eb93fc	29	#include <stdlib.h>
06afffcc	30	#include <errno.h>
4f333a8b	31	#include <cstring>
ea542140 DK	32
	33	#include <apti18n.h>
	34	/}}}/
578bfd0a AL	35
	36	// MMap::MMap - Constructor /{{{/
	37	// ---------------------------------------------------------------------
	38	/* */
2d11135a	39	MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0),
06afffcc	40	Base(0), SyncToFd(NULL)
578bfd0a AL	41	{
578bfd0a AL	42	if ((Flags & NoImmMap) != NoImmMap)
2d11135a AL	43	Map(F);
	44	}
	45	/}}}/
	46	// MMap::MMap - Constructor /{{{/
	47	// ---------------------------------------------------------------------
	48	/* */
	49	MMap::MMap(unsigned long Flags) : Flags(Flags), iSize(0),
06afffcc	50	Base(0), SyncToFd(NULL)
2d11135a	51	{
578bfd0a AL	52	}
	53	/}}}/
	54	// MMap::~MMap - Destructor /{{{/
	55	// ---------------------------------------------------------------------
	56	/* */
	57	MMap::~MMap()
	58	{
2d11135a	59	Close();
578bfd0a AL	60	}
	61	/}}}/
	62	// MMap::Map - Perform the mapping /{{{/
	63	// ---------------------------------------------------------------------
	64	/* */
2d11135a	65	bool MMap::Map(FileFd &Fd)
578bfd0a AL	66	{
	67	iSize = Fd.Size();
	68
	69	// Set the permissions.
	70	int Prot = PROT_READ;
	71	int Map = MAP_SHARED;
	72	if ((Flags & ReadOnly) != ReadOnly)
	73	Prot \|= PROT_WRITE;
	74	if ((Flags & Public) != Public)
	75	Map = MAP_PRIVATE;
	76
b35d2f5f	77	if (iSize == 0)
b2e465d6	78	return _error->Error(_("Can't mmap an empty file"));
b35d2f5f	79
578bfd0a AL	80	// Map it.
	81	Base = mmap(0,iSize,Prot,Map,Fd.Fd(),0);
	82	if (Base == (void *)-1)
06afffcc DK	83	{
	84	if (errno == ENODEV \|\| errno == EINVAL)
	85	{
	86	// The filesystem doesn't support this particular kind of mmap.
	87	// So we allocate a buffer and read the whole file into it.
	88	int const dupped_fd = dup(Fd.Fd());
	89	if (dupped_fd == -1)
	90	return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd());
	91
	92	Base = new unsigned char[iSize];
	93	SyncToFd = new FileFd (dupped_fd);
	94	if (!SyncToFd->Seek(0L) \|\| !SyncToFd->Read(Base, iSize))
	95	return false;
	96	}
	97	else
650faab0	98	return _error->Errno("mmap",_("Couldn't make mmap of %llu bytes"),
06afffcc DK	99	iSize);
06afffcc DK	100	}
578bfd0a AL	101
	102	return true;
	103	}
	104	/}}}/
	105	// MMap::Close - Close the map /{{{/
	106	// ---------------------------------------------------------------------
	107	/* */
2d11135a	108	bool MMap::Close(bool DoSync)
578bfd0a	109	{
2a79d5b5	110	if ((Flags & UnMapped) == UnMapped \|\| validData() == false \|\| iSize == 0)
578bfd0a	111	return true;
2d11135a	112
1164783d AL	113	if (DoSync == true)
1164783d AL	114	Sync();
06afffcc DK	115
	116	if (SyncToFd != NULL)
	117	{
	118	delete[] (char *)Base;
	119	delete SyncToFd;
	120	SyncToFd = NULL;
	121	}
	122	else
	123	{
	124	if (munmap((char *)Base, iSize) != 0)
	125	_error->WarningE("mmap", _("Unable to close mmap"));
	126	}
	127
578bfd0a	128	iSize = 0;
b2e465d6	129	Base = 0;
578bfd0a AL	130	return true;
	131	}
	132	/}}}/
	133	// MMap::Sync - Syncronize the map with the disk /{{{/
	134	// ---------------------------------------------------------------------
0149949b AL	135	/* This is done in syncronous mode - the docs indicate that this will
0149949b AL	136	not return till all IO is complete */
578bfd0a AL	137	bool MMap::Sync()
578bfd0a AL	138	{
2d11135a AL	139	if ((Flags & UnMapped) == UnMapped)
	140	return true;
	141
de3c15ea	142	#ifdef _POSIX_SYNCHRONIZED_IO
1164783d	143	if ((Flags & ReadOnly) != ReadOnly)
06afffcc DK	144	{
	145	if (SyncToFd != NULL)
	146	{
	147	if (!SyncToFd->Seek(0) \|\| !SyncToFd->Write(Base, iSize))
	148	return false;
	149	}
	150	else
	151	{
	152	if (msync((char *)Base, iSize, MS_SYNC) < 0)
	153	return _error->Errno("msync", _("Unable to synchronize mmap"));
	154	}
	155	}
de3c15ea	156	#endif
578bfd0a AL	157	return true;
	158	}
	159	/}}}/
	160	// MMap::Sync - Syncronize a section of the file to disk /{{{/
	161	// ---------------------------------------------------------------------
	162	/* */
	163	bool MMap::Sync(unsigned long Start,unsigned long Stop)
	164	{
2d11135a AL	165	if ((Flags & UnMapped) == UnMapped)
	166	return true;
	167
35c22def	168	#ifdef _POSIX_SYNCHRONIZED_IO
650faab0	169	unsigned long long PSize = sysconf(_SC_PAGESIZE);
1164783d	170	if ((Flags & ReadOnly) != ReadOnly)
06afffcc DK	171	{
	172	if (SyncToFd != 0)
	173	{
	174	if (!SyncToFd->Seek(0) \|\|
	175	!SyncToFd->Write (((char *)Base)+Start, Stop-Start))
	176	return false;
	177	}
	178	else
	179	{
650faab0	180	if (msync((char )Base+(unsigned long long)(Start/PSize)PSize,Stop - Start,MS_SYNC) < 0)
06afffcc DK	181	return _error->Errno("msync", _("Unable to synchronize mmap"));
	182	}
	183	}
de3c15ea	184	#endif
578bfd0a AL	185	return true;
	186	}
	187	/}}}/
	188
	189	// DynamicMMap::DynamicMMap - Constructor /{{{/
	190	// ---------------------------------------------------------------------
	191	/* */
d6c4a976 DK	192	DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long const &Workspace,
	193	unsigned long const &Grow, unsigned long const &Limit) :
	194	MMap(F,Flags \| NoImmMap), Fd(&F), WorkSpace(Workspace),
	195	GrowFactor(Grow), Limit(Limit)
578bfd0a	196	{
d38b7b3d AL	197	if (_error->PendingError() == true)
	198	return;
	199
650faab0	200	unsigned long long EndOfFile = Fd->Size();
b2e465d6 AL	201	if (EndOfFile > WorkSpace)
b2e465d6 AL	202	WorkSpace = EndOfFile;
ea92d036	203	else if(WorkSpace > 0)
b2e465d6	204	{
ea92d036	205	Fd->Seek(WorkSpace - 1);
b2e465d6 AL	206	char C = 0;
	207	Fd->Write(&C,sizeof(C));
	208	}
	209
2d11135a	210	Map(F);
578bfd0a AL	211	iSize = EndOfFile;
	212	}
	213	/}}}/
2d11135a AL	214	// DynamicMMap::DynamicMMap - Constructor for a non-file backed map /{{{/
2d11135a AL	215	// ---------------------------------------------------------------------
f1c6a8ca DK	216	/* We try here to use mmap to reserve some space - this is much more
	217	cooler than the fallback solution to simply allocate a char array
	218	and could come in handy later than we are able to grow such an mmap */
d6c4a976 DK	219	DynamicMMap::DynamicMMap(unsigned long Flags,unsigned long const &WorkSpace,
	220	unsigned long const &Grow, unsigned long const &Limit) :
	221	MMap(Flags \| NoImmMap \| UnMapped), Fd(0), WorkSpace(WorkSpace),
	222	GrowFactor(Grow), Limit(Limit)
2d11135a	223	{
d6c4a976 DK	224	if (_error->PendingError() == true)
	225	return;
	226
	227	// disable Moveable if we don't grow
	228	if (Grow == 0)
a9fe5928	229	this->Flags &= ~Moveable;
d6c4a976 DK	230
	231	#ifndef __linux__
	232	// kfreebsd doesn't have mremap, so we use the fallback
a9fe5928 DK	233	if ((this->Flags & Moveable) == Moveable)
a9fe5928 DK	234	this->Flags \|= Fallback;
d6c4a976	235	#endif
f1c6a8ca DK	236
f1c6a8ca DK	237	#ifdef _POSIX_MAPPED_FILES
a9fe5928	238	if ((this->Flags & Fallback) != Fallback) {
d6c4a976 DK	239	// Set the permissions.
d6c4a976 DK	240	int Prot = PROT_READ;
f895e2ce	241	#ifdef MAP_ANONYMOUS
d6c4a976	242	int Map = MAP_PRIVATE \| MAP_ANONYMOUS;
f895e2ce DK	243	#else
	244	int Map = MAP_PRIVATE \| MAP_ANON;
	245	#endif
a9fe5928	246	if ((this->Flags & ReadOnly) != ReadOnly)
d6c4a976	247	Prot \|= PROT_WRITE;
a9fe5928	248	if ((this->Flags & Public) == Public)
f895e2ce	249	#ifdef MAP_ANONYMOUS
d6c4a976	250	Map = MAP_SHARED \| MAP_ANONYMOUS;
f895e2ce DK	251	#else
	252	Map = MAP_SHARED \| MAP_ANON;
	253	#endif
eb162ff7	254
d6c4a976 DK	255	// use anonymous mmap() to get the memory
d6c4a976 DK	256	Base = (unsigned char*) mmap(0, WorkSpace, Prot, Map, -1, 0);
eb162ff7	257
d6c4a976 DK	258	if(Base == MAP_FAILED)
	259	_error->Errno("DynamicMMap",_("Couldn't make mmap of %lu bytes"),WorkSpace);
	260
	261	iSize = 0;
	262	return;
	263	}
d5972534	264	#endif
d6c4a976 DK	265	// fallback to a static allocated space
	266	Base = new unsigned char[WorkSpace];
	267	memset(Base,0,WorkSpace);
	268	iSize = 0;
2d11135a AL	269	}
2d11135a AL	270	/}}}/
578bfd0a AL	271	// DynamicMMap::~DynamicMMap - Destructor /{{{/
	272	// ---------------------------------------------------------------------
	273	/* We truncate the file to the size of the memory data set */
	274	DynamicMMap::~DynamicMMap()
	275	{
2d11135a AL	276	if (Fd == 0)
2d11135a AL	277	{
2a79d5b5	278	if (validData() == false)
26b37f95	279	return;
f1c6a8ca	280	#ifdef _POSIX_MAPPED_FILES
a67de73e	281	munmap(Base, WorkSpace);
f1c6a8ca	282	#else
2d11135a	283	delete [] (unsigned char *)Base;
f1c6a8ca	284	#endif
2d11135a AL	285	return;
	286	}
	287
650faab0	288	unsigned long long EndOfFile = iSize;
1164783d	289	iSize = WorkSpace;
2d11135a	290	Close(false);
3c8cda8b MV	291	if(ftruncate(Fd->Fd(),EndOfFile) < 0)
3c8cda8b MV	292	_error->Errno("ftruncate", _("Failed to truncate file"));
578bfd0a AL	293	}
	294	/}}}/
	295	// DynamicMMap::RawAllocate - Allocate a raw chunk of unaligned space /{{{/
	296	// ---------------------------------------------------------------------
f55a958f	297	/* This allocates a block of memory aligned to the given size */
650faab0	298	unsigned long DynamicMMap::RawAllocate(unsigned long long Size,unsigned long Aln)
578bfd0a	299	{
650faab0	300	unsigned long long Result = iSize;
f55a958f AL	301	if (Aln != 0)
f55a958f AL	302	Result += Aln - (iSize%Aln);
c5f44afc	303
f55a958f	304	iSize = Result + Size;
c5f44afc	305
f1c6a8ca DK	306	// try to grow the buffer
f1c6a8ca DK	307	while(Result + Size > WorkSpace)
578bfd0a	308	{
f1c6a8ca DK	309	if(!Grow())
f1c6a8ca DK	310	{
5afa55c6	311	_error->Fatal(_("Dynamic MMap ran out of room. Please increase the size "
f1c6a8ca DK	312	"of APT::Cache-Limit. Current value: %lu. (man 5 apt.conf)"), WorkSpace);
	313	return 0;
	314	}
578bfd0a	315	}
578bfd0a AL	316	return Result;
	317	}
	318	/}}}/
	319	// DynamicMMap::Allocate - Pooled aligned allocation /{{{/
	320	// ---------------------------------------------------------------------
	321	/* This allocates an Item of size ItemSize so that it is aligned to its
	322	size in the file. */
	323	unsigned long DynamicMMap::Allocate(unsigned long ItemSize)
c5f44afc	324	{
578bfd0a AL	325	// Look for a matching pool entry
	326	Pool *I;
	327	Pool *Empty = 0;
a9fe5928	328	for (I = Pools; I != Pools + PoolCount; ++I)
578bfd0a AL	329	{
	330	if (I->ItemSize == 0)
	331	Empty = I;
	332	if (I->ItemSize == ItemSize)
	333	break;
	334	}
578bfd0a AL	335	// No pool is allocated, use an unallocated one
	336	if (I == Pools + PoolCount)
	337	{
	338	// Woops, we ran out, the calling code should allocate more.
	339	if (Empty == 0)
	340	{
	341	_error->Error("Ran out of allocation pools");
	342	return 0;
	343	}
	344
	345	I = Empty;
	346	I->ItemSize = ItemSize;
	347	I->Count = 0;
	348	}
c5f44afc DK	349
c5f44afc DK	350	unsigned long Result = 0;
578bfd0a AL	351	// Out of space, allocate some more
	352	if (I->Count == 0)
	353	{
c5f44afc DK	354	const unsigned long size = 20*1024;
c5f44afc DK	355	I->Count = size/ItemSize;
a9fe5928	356	Pool* oldPools = Pools;
c5f44afc	357	Result = RawAllocate(size,ItemSize);
a9fe5928 DK	358	if (Pools != oldPools)
	359	I += Pools - oldPools;
	360
c5f44afc DK	361	// Does the allocation failed ?
	362	if (Result == 0 && _error->PendingError())
	363	return 0;
	364	I->Start = Result;
	365	}
	366	else
	367	Result = I->Start;
f55a958f	368
578bfd0a	369	I->Count--;
c5f44afc	370	I->Start += ItemSize;
578bfd0a AL	371	return Result/ItemSize;
	372	}
	373	/}}}/
	374	// DynamicMMap::WriteString - Write a string to the file /{{{/
	375	// ---------------------------------------------------------------------
	376	/* Strings are not aligned to anything */
	377	unsigned long DynamicMMap::WriteString(const char *String,
	378	unsigned long Len)
	379	{
6e52073f	380	if (Len == (unsigned long)-1)
578bfd0a	381	Len = strlen(String);
c5f44afc	382
a9fe5928	383	unsigned long const Result = RawAllocate(Len+1,0);
c5f44afc DK	384
	385	if (Result == 0 && _error->PendingError())
	386	return 0;
	387
578bfd0a AL	388	memcpy((char *)Base + Result,String,Len);
	389	((char *)Base)[Result + Len] = 0;
	390	return Result;
	391	}
	392	/}}}/
f1c6a8ca DK	393	// DynamicMMap::Grow - Grow the mmap /{{{/
f1c6a8ca DK	394	// ---------------------------------------------------------------------
d6c4a976 DK	395	/* This method is a wrapper around different methods to (try to) grow
	396	a mmap (or our char[]-fallback). Encounterable environments:
	397	1. Moveable + !Fallback + linux -> mremap with MREMAP_MAYMOVE
	398	2. Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
	399	3. Moveable + Fallback -> realloc
	400	4. !Moveable + !Fallback + linux -> mremap alone - which will fail in 99,9%
	401	5. !Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
	402	6. !Moveable + Fallback -> not possible
	403	[ While Moveable and Fallback stands for the equally named flags and
	404	"linux" indicates a linux kernel instead of a freebsd kernel. ]
	405	So what you can see here is, that a MMAP which want to be growable need
	406	to be moveable to have a real chance but that this method will at least try
	407	the nearly impossible 4 to grow it before it finally give up: Never say never. */
	408	bool DynamicMMap::Grow() {
	409	if (Limit != 0 && WorkSpace >= Limit)
e3ac3b46 DK	410	return _error->Error(_("Unable to increase the size of the MMap as the "
e3ac3b46 DK	411	"limit of %lu bytes is already reached."), Limit);
dcdf1ef1 DK	412	if (GrowFactor <= 0)
dcdf1ef1 DK	413	return _error->Error(_("Unable to increase size of the MMap as automatic growing is disabled by user."));
f1c6a8ca	414
650faab0	415	unsigned long long const newSize = WorkSpace + GrowFactor;
f1c6a8ca	416
d6c4a976 DK	417	if(Fd != 0) {
	418	Fd->Seek(newSize - 1);
	419	char C = 0;
	420	Fd->Write(&C,sizeof(C));
	421	}
a9fe5928 DK	422
	423	unsigned long const poolOffset = Pools - ((Pool*) Base);
	424
d6c4a976 DK	425	if ((Flags & Fallback) != Fallback) {
	426	#if defined(_POSIX_MAPPED_FILES) && defined(__linux__)
	427	#ifdef MREMAP_MAYMOVE
a9fe5928	428
d6c4a976 DK	429	if ((Flags & Moveable) == Moveable)
	430	Base = mremap(Base, WorkSpace, newSize, MREMAP_MAYMOVE);
	431	else
	432	#endif
	433	Base = mremap(Base, WorkSpace, newSize, 0);
f1c6a8ca	434
d6c4a976 DK	435	if(Base == MAP_FAILED)
d6c4a976 DK	436	return false;
f1c6a8ca	437	#else
d6c4a976	438	return false;
f1c6a8ca	439	#endif
d6c4a976 DK	440	} else {
	441	if ((Flags & Moveable) != Moveable)
	442	return false;
	443
	444	Base = realloc(Base, newSize);
	445	if (Base == NULL)
	446	return false;
	447	}
	448
a9fe5928	449	Pools =(Pool*) Base + poolOffset;
d6c4a976 DK	450	WorkSpace = newSize;
d6c4a976 DK	451	return true;
f1c6a8ca DK	452	}
f1c6a8ca DK	453	/}}}/