[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 <apt-pkg/fileutl.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"));

   // We can't mmap compressed fd's directly, so we need to read it completely
   if (Fd.IsCompressed() == true)
   {
      if ((Flags & ReadOnly) != ReadOnly)
	 return _error->Error("Compressed file %s can only be mapped readonly", Fd.Name().c_str());
      Base = malloc(iSize);
      SyncToFd = new FileFd();
      if (Fd.Seek(0L) == false || Fd.Read(Base, iSize) == false)
	 return _error->Error("Compressed file %s can't be read into mmap", Fd.Name().c_str());
      return true;
   }

   // Map it.
   Base = (Flags & Fallback) ? MAP_FAILED : mmap(0,iSize,Prot,Map,Fd.Fd(),0);
   if (Base == (void *)-1)
   {
      if (errno == ENODEV || errno == EINVAL || (Flags & Fallback))
      {
	 // The filesystem doesn't support this particular kind of mmap.
	 // So we allocate a buffer and read the whole file into it.
	 if ((Flags & ReadOnly) == ReadOnly)
	 {
	    // for readonly, we don't need sync, so make it simple
	    Base = malloc(iSize);
	    SyncToFd = new FileFd();
	    return Fd.Read(Base, iSize);
	 }
	 // FIXME: Writing to compressed fd's ?
	 int const dupped_fd = dup(Fd.Fd());
	 if (dupped_fd == -1)
	    return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd());

	 Base = calloc(iSize, 1);
	 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)
   {
      free(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;

   // 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

   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 = calloc(WorkSpace, 1);
	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
      free(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-Start. 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;
		else
			/* Set new memory to 0 */
			memset((char*)Base + WorkSpace, 0, newSize - WorkSpace);
	}

	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>
472ff00e	24	#include <apt-pkg/fileutl.h>
578bfd0a AL	25
	26	#include <sys/mman.h>
	27	#include <sys/stat.h>
578bfd0a AL	28	#include <unistd.h>
578bfd0a AL	29	#include <fcntl.h>
13eb93fc	30	#include <stdlib.h>
06afffcc	31	#include <errno.h>
4f333a8b	32	#include <cstring>
ea542140 DK	33
	34	#include <apti18n.h>
	35	/}}}/
578bfd0a AL	36
	37	// MMap::MMap - Constructor /{{{/
	38	// ---------------------------------------------------------------------
	39	/* */
2d11135a	40	MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0),
06afffcc	41	Base(0), SyncToFd(NULL)
578bfd0a AL	42	{
578bfd0a AL	43	if ((Flags & NoImmMap) != NoImmMap)
2d11135a AL	44	Map(F);
	45	}
	46	/}}}/
	47	// MMap::MMap - Constructor /{{{/
	48	// ---------------------------------------------------------------------
	49	/* */
	50	MMap::MMap(unsigned long Flags) : Flags(Flags), iSize(0),
06afffcc	51	Base(0), SyncToFd(NULL)
2d11135a	52	{
578bfd0a AL	53	}
	54	/}}}/
	55	// MMap::~MMap - Destructor /{{{/
	56	// ---------------------------------------------------------------------
	57	/* */
	58	MMap::~MMap()
	59	{
2d11135a	60	Close();
578bfd0a AL	61	}
	62	/}}}/
	63	// MMap::Map - Perform the mapping /{{{/
	64	// ---------------------------------------------------------------------
	65	/* */
2d11135a	66	bool MMap::Map(FileFd &Fd)
578bfd0a AL	67	{
578bfd0a AL	68	iSize = Fd.Size();
699b209e	69
578bfd0a AL	70	// Set the permissions.
	71	int Prot = PROT_READ;
	72	int Map = MAP_SHARED;
	73	if ((Flags & ReadOnly) != ReadOnly)
	74	Prot \|= PROT_WRITE;
	75	if ((Flags & Public) != Public)
	76	Map = MAP_PRIVATE;
	77
b35d2f5f	78	if (iSize == 0)
b2e465d6	79	return _error->Error(_("Can't mmap an empty file"));
032bd56f DK	80
	81	// We can't mmap compressed fd's directly, so we need to read it completely
	82	if (Fd.IsCompressed() == true)
	83	{
	84	if ((Flags & ReadOnly) != ReadOnly)
	85	return _error->Error("Compressed file %s can only be mapped readonly", Fd.Name().c_str());
7899a133	86	Base = malloc(iSize);
6bae2c51	87	SyncToFd = new FileFd();
032bd56f	88	if (Fd.Seek(0L) == false \|\| Fd.Read(Base, iSize) == false)
b711c01e	89	return _error->Error("Compressed file %s can't be read into mmap", Fd.Name().c_str());
032bd56f DK	90	return true;
	91	}
	92
578bfd0a	93	// Map it.
7899a133	94	Base = (Flags & Fallback) ? MAP_FAILED : mmap(0,iSize,Prot,Map,Fd.Fd(),0);
578bfd0a	95	if (Base == (void *)-1)
06afffcc	96	{
7899a133	97	if (errno == ENODEV \|\| errno == EINVAL \|\| (Flags & Fallback))
06afffcc DK	98	{
	99	// The filesystem doesn't support this particular kind of mmap.
	100	// So we allocate a buffer and read the whole file into it.
699b209e DK	101	if ((Flags & ReadOnly) == ReadOnly)
	102	{
	103	// for readonly, we don't need sync, so make it simple
7899a133	104	Base = malloc(iSize);
fbda0ee9	105	SyncToFd = new FileFd();
699b209e DK	106	return Fd.Read(Base, iSize);
	107	}
	108	// FIXME: Writing to compressed fd's ?
06afffcc DK	109	int const dupped_fd = dup(Fd.Fd());
	110	if (dupped_fd == -1)
	111	return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd());
	112
7899a133	113	Base = calloc(iSize, 1);
06afffcc DK	114	SyncToFd = new FileFd (dupped_fd);
	115	if (!SyncToFd->Seek(0L) \|\| !SyncToFd->Read(Base, iSize))
	116	return false;
	117	}
	118	else
650faab0	119	return _error->Errno("mmap",_("Couldn't make mmap of %llu bytes"),
06afffcc DK	120	iSize);
06afffcc DK	121	}
578bfd0a AL	122
	123	return true;
	124	}
	125	/}}}/
	126	// MMap::Close - Close the map /{{{/
	127	// ---------------------------------------------------------------------
	128	/* */
2d11135a	129	bool MMap::Close(bool DoSync)
578bfd0a	130	{
2a79d5b5	131	if ((Flags & UnMapped) == UnMapped \|\| validData() == false \|\| iSize == 0)
578bfd0a	132	return true;
2d11135a	133
1164783d AL	134	if (DoSync == true)
1164783d AL	135	Sync();
06afffcc DK	136
	137	if (SyncToFd != NULL)
	138	{
7899a133	139	free(Base);
06afffcc DK	140	delete SyncToFd;
	141	SyncToFd = NULL;
	142	}
	143	else
	144	{
	145	if (munmap((char *)Base, iSize) != 0)
	146	_error->WarningE("mmap", _("Unable to close mmap"));
	147	}
	148
578bfd0a	149	iSize = 0;
b2e465d6	150	Base = 0;
578bfd0a AL	151	return true;
	152	}
	153	/}}}/
	154	// MMap::Sync - Syncronize the map with the disk /{{{/
	155	// ---------------------------------------------------------------------
0149949b AL	156	/* This is done in syncronous mode - the docs indicate that this will
0149949b AL	157	not return till all IO is complete */
578bfd0a AL	158	bool MMap::Sync()
578bfd0a AL	159	{
2d11135a AL	160	if ((Flags & UnMapped) == UnMapped)
	161	return true;
	162
de3c15ea	163	#ifdef _POSIX_SYNCHRONIZED_IO
1164783d	164	if ((Flags & ReadOnly) != ReadOnly)
06afffcc DK	165	{
	166	if (SyncToFd != NULL)
	167	{
	168	if (!SyncToFd->Seek(0) \|\| !SyncToFd->Write(Base, iSize))
	169	return false;
	170	}
	171	else
	172	{
	173	if (msync((char *)Base, iSize, MS_SYNC) < 0)
	174	return _error->Errno("msync", _("Unable to synchronize mmap"));
	175	}
	176	}
de3c15ea	177	#endif
578bfd0a AL	178	return true;
	179	}
	180	/}}}/
	181	// MMap::Sync - Syncronize a section of the file to disk /{{{/
	182	// ---------------------------------------------------------------------
	183	/* */
	184	bool MMap::Sync(unsigned long Start,unsigned long Stop)
	185	{
2d11135a AL	186	if ((Flags & UnMapped) == UnMapped)
	187	return true;
	188
35c22def	189	#ifdef _POSIX_SYNCHRONIZED_IO
650faab0	190	unsigned long long PSize = sysconf(_SC_PAGESIZE);
1164783d	191	if ((Flags & ReadOnly) != ReadOnly)
06afffcc DK	192	{
	193	if (SyncToFd != 0)
	194	{
	195	if (!SyncToFd->Seek(0) \|\|
	196	!SyncToFd->Write (((char *)Base)+Start, Stop-Start))
	197	return false;
	198	}
	199	else
	200	{
650faab0	201	if (msync((char )Base+(unsigned long long)(Start/PSize)PSize,Stop - Start,MS_SYNC) < 0)
06afffcc DK	202	return _error->Errno("msync", _("Unable to synchronize mmap"));
	203	}
	204	}
de3c15ea	205	#endif
578bfd0a AL	206	return true;
	207	}
	208	/}}}/
	209
	210	// DynamicMMap::DynamicMMap - Constructor /{{{/
	211	// ---------------------------------------------------------------------
	212	/* */
d6c4a976 DK	213	DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long const &Workspace,
	214	unsigned long const &Grow, unsigned long const &Limit) :
	215	MMap(F,Flags \| NoImmMap), Fd(&F), WorkSpace(Workspace),
	216	GrowFactor(Grow), Limit(Limit)
578bfd0a	217	{
d38b7b3d AL	218	if (_error->PendingError() == true)
d38b7b3d AL	219	return;
7b15b702 DK	220
	221	// disable Moveable if we don't grow
	222	if (Grow == 0)
	223	this->Flags &= ~Moveable;
	224
	225	#ifndef __linux__
	226	// kfreebsd doesn't have mremap, so we use the fallback
	227	if ((this->Flags & Moveable) == Moveable)
	228	this->Flags \|= Fallback;
	229	#endif
	230
650faab0	231	unsigned long long EndOfFile = Fd->Size();
b2e465d6 AL	232	if (EndOfFile > WorkSpace)
b2e465d6 AL	233	WorkSpace = EndOfFile;
ea92d036	234	else if(WorkSpace > 0)
b2e465d6	235	{
ea92d036	236	Fd->Seek(WorkSpace - 1);
b2e465d6 AL	237	char C = 0;
	238	Fd->Write(&C,sizeof(C));
	239	}
	240
2d11135a	241	Map(F);
578bfd0a AL	242	iSize = EndOfFile;
	243	}
	244	/}}}/
2d11135a AL	245	// DynamicMMap::DynamicMMap - Constructor for a non-file backed map /{{{/
2d11135a AL	246	// ---------------------------------------------------------------------
f1c6a8ca DK	247	/* We try here to use mmap to reserve some space - this is much more
	248	cooler than the fallback solution to simply allocate a char array
	249	and could come in handy later than we are able to grow such an mmap */
d6c4a976 DK	250	DynamicMMap::DynamicMMap(unsigned long Flags,unsigned long const &WorkSpace,
	251	unsigned long const &Grow, unsigned long const &Limit) :
	252	MMap(Flags \| NoImmMap \| UnMapped), Fd(0), WorkSpace(WorkSpace),
	253	GrowFactor(Grow), Limit(Limit)
2d11135a	254	{
d6c4a976 DK	255	if (_error->PendingError() == true)
	256	return;
	257
	258	// disable Moveable if we don't grow
	259	if (Grow == 0)
a9fe5928	260	this->Flags &= ~Moveable;
d6c4a976 DK	261
	262	#ifndef __linux__
	263	// kfreebsd doesn't have mremap, so we use the fallback
a9fe5928 DK	264	if ((this->Flags & Moveable) == Moveable)
a9fe5928 DK	265	this->Flags \|= Fallback;
d6c4a976	266	#endif
f1c6a8ca DK	267
f1c6a8ca DK	268	#ifdef _POSIX_MAPPED_FILES
a9fe5928	269	if ((this->Flags & Fallback) != Fallback) {
d6c4a976 DK	270	// Set the permissions.
d6c4a976 DK	271	int Prot = PROT_READ;
f895e2ce	272	#ifdef MAP_ANONYMOUS
d6c4a976	273	int Map = MAP_PRIVATE \| MAP_ANONYMOUS;
f895e2ce DK	274	#else
	275	int Map = MAP_PRIVATE \| MAP_ANON;
	276	#endif
a9fe5928	277	if ((this->Flags & ReadOnly) != ReadOnly)
d6c4a976	278	Prot \|= PROT_WRITE;
a9fe5928	279	if ((this->Flags & Public) == Public)
f895e2ce	280	#ifdef MAP_ANONYMOUS
d6c4a976	281	Map = MAP_SHARED \| MAP_ANONYMOUS;
f895e2ce DK	282	#else
	283	Map = MAP_SHARED \| MAP_ANON;
	284	#endif
eb162ff7	285
d6c4a976 DK	286	// use anonymous mmap() to get the memory
d6c4a976 DK	287	Base = (unsigned char*) mmap(0, WorkSpace, Prot, Map, -1, 0);
eb162ff7	288
d6c4a976 DK	289	if(Base == MAP_FAILED)
	290	_error->Errno("DynamicMMap",_("Couldn't make mmap of %lu bytes"),WorkSpace);
	291
	292	iSize = 0;
	293	return;
	294	}
d5972534	295	#endif
d6c4a976	296	// fallback to a static allocated space
7899a133	297	Base = calloc(WorkSpace, 1);
d6c4a976	298	iSize = 0;
2d11135a AL	299	}
2d11135a AL	300	/}}}/
578bfd0a AL	301	// DynamicMMap::~DynamicMMap - Destructor /{{{/
	302	// ---------------------------------------------------------------------
	303	/* We truncate the file to the size of the memory data set */
	304	DynamicMMap::~DynamicMMap()
	305	{
2d11135a AL	306	if (Fd == 0)
2d11135a AL	307	{
2a79d5b5	308	if (validData() == false)
26b37f95	309	return;
f1c6a8ca	310	#ifdef _POSIX_MAPPED_FILES
a67de73e	311	munmap(Base, WorkSpace);
f1c6a8ca	312	#else
7899a133	313	free(Base);
f1c6a8ca	314	#endif
2d11135a AL	315	return;
	316	}
	317
650faab0	318	unsigned long long EndOfFile = iSize;
1164783d	319	iSize = WorkSpace;
2d11135a	320	Close(false);
3c8cda8b MV	321	if(ftruncate(Fd->Fd(),EndOfFile) < 0)
3c8cda8b MV	322	_error->Errno("ftruncate", _("Failed to truncate file"));
578bfd0a AL	323	}
	324	/}}}/
	325	// DynamicMMap::RawAllocate - Allocate a raw chunk of unaligned space /{{{/
	326	// ---------------------------------------------------------------------
f55a958f	327	/* This allocates a block of memory aligned to the given size */
650faab0	328	unsigned long DynamicMMap::RawAllocate(unsigned long long Size,unsigned long Aln)
578bfd0a	329	{
650faab0	330	unsigned long long Result = iSize;
f55a958f AL	331	if (Aln != 0)
f55a958f AL	332	Result += Aln - (iSize%Aln);
c5f44afc	333
f55a958f	334	iSize = Result + Size;
c5f44afc	335
f1c6a8ca DK	336	// try to grow the buffer
f1c6a8ca DK	337	while(Result + Size > WorkSpace)
578bfd0a	338	{
f1c6a8ca DK	339	if(!Grow())
f1c6a8ca DK	340	{
5afa55c6	341	_error->Fatal(_("Dynamic MMap ran out of room. Please increase the size "
4bd60a02	342	"of APT::Cache-Start. Current value: %lu. (man 5 apt.conf)"), WorkSpace);
f1c6a8ca DK	343	return 0;
f1c6a8ca DK	344	}
578bfd0a	345	}
578bfd0a AL	346	return Result;
	347	}
	348	/}}}/
	349	// DynamicMMap::Allocate - Pooled aligned allocation /{{{/
	350	// ---------------------------------------------------------------------
	351	/* This allocates an Item of size ItemSize so that it is aligned to its
	352	size in the file. */
	353	unsigned long DynamicMMap::Allocate(unsigned long ItemSize)
c5f44afc	354	{
578bfd0a AL	355	// Look for a matching pool entry
	356	Pool *I;
	357	Pool *Empty = 0;
a9fe5928	358	for (I = Pools; I != Pools + PoolCount; ++I)
578bfd0a AL	359	{
	360	if (I->ItemSize == 0)
	361	Empty = I;
	362	if (I->ItemSize == ItemSize)
	363	break;
	364	}
578bfd0a AL	365	// No pool is allocated, use an unallocated one
	366	if (I == Pools + PoolCount)
	367	{
	368	// Woops, we ran out, the calling code should allocate more.
	369	if (Empty == 0)
	370	{
	371	_error->Error("Ran out of allocation pools");
	372	return 0;
	373	}
	374
	375	I = Empty;
	376	I->ItemSize = ItemSize;
	377	I->Count = 0;
	378	}
c5f44afc DK	379
c5f44afc DK	380	unsigned long Result = 0;
578bfd0a AL	381	// Out of space, allocate some more
	382	if (I->Count == 0)
	383	{
c5f44afc DK	384	const unsigned long size = 20*1024;
c5f44afc DK	385	I->Count = size/ItemSize;
a9fe5928	386	Pool* oldPools = Pools;
c5f44afc	387	Result = RawAllocate(size,ItemSize);
a9fe5928 DK	388	if (Pools != oldPools)
	389	I += Pools - oldPools;
	390
c5f44afc DK	391	// Does the allocation failed ?
	392	if (Result == 0 && _error->PendingError())
	393	return 0;
	394	I->Start = Result;
	395	}
	396	else
	397	Result = I->Start;
f55a958f	398
578bfd0a	399	I->Count--;
c5f44afc	400	I->Start += ItemSize;
578bfd0a AL	401	return Result/ItemSize;
	402	}
	403	/}}}/
	404	// DynamicMMap::WriteString - Write a string to the file /{{{/
	405	// ---------------------------------------------------------------------
	406	/* Strings are not aligned to anything */
	407	unsigned long DynamicMMap::WriteString(const char *String,
	408	unsigned long Len)
	409	{
6e52073f	410	if (Len == (unsigned long)-1)
578bfd0a	411	Len = strlen(String);
c5f44afc	412
a9fe5928	413	unsigned long const Result = RawAllocate(Len+1,0);
c5f44afc DK	414
	415	if (Result == 0 && _error->PendingError())
	416	return 0;
	417
578bfd0a AL	418	memcpy((char *)Base + Result,String,Len);
	419	((char *)Base)[Result + Len] = 0;
	420	return Result;
	421	}
	422	/}}}/
f1c6a8ca DK	423	// DynamicMMap::Grow - Grow the mmap /{{{/
f1c6a8ca DK	424	// ---------------------------------------------------------------------
d6c4a976 DK	425	/* This method is a wrapper around different methods to (try to) grow
	426	a mmap (or our char[]-fallback). Encounterable environments:
	427	1. Moveable + !Fallback + linux -> mremap with MREMAP_MAYMOVE
	428	2. Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
	429	3. Moveable + Fallback -> realloc
	430	4. !Moveable + !Fallback + linux -> mremap alone - which will fail in 99,9%
	431	5. !Moveable + !Fallback + !linux -> not possible (forbidden by constructor)
	432	6. !Moveable + Fallback -> not possible
	433	[ While Moveable and Fallback stands for the equally named flags and
	434	"linux" indicates a linux kernel instead of a freebsd kernel. ]
	435	So what you can see here is, that a MMAP which want to be growable need
	436	to be moveable to have a real chance but that this method will at least try
	437	the nearly impossible 4 to grow it before it finally give up: Never say never. */
	438	bool DynamicMMap::Grow() {
	439	if (Limit != 0 && WorkSpace >= Limit)
e3ac3b46 DK	440	return _error->Error(_("Unable to increase the size of the MMap as the "
e3ac3b46 DK	441	"limit of %lu bytes is already reached."), Limit);
dcdf1ef1 DK	442	if (GrowFactor <= 0)
dcdf1ef1 DK	443	return _error->Error(_("Unable to increase size of the MMap as automatic growing is disabled by user."));
f1c6a8ca	444
650faab0	445	unsigned long long const newSize = WorkSpace + GrowFactor;
f1c6a8ca	446
d6c4a976 DK	447	if(Fd != 0) {
	448	Fd->Seek(newSize - 1);
	449	char C = 0;
	450	Fd->Write(&C,sizeof(C));
	451	}
a9fe5928 DK	452
	453	unsigned long const poolOffset = Pools - ((Pool*) Base);
	454
d6c4a976 DK	455	if ((Flags & Fallback) != Fallback) {
	456	#if defined(_POSIX_MAPPED_FILES) && defined(__linux__)
	457	#ifdef MREMAP_MAYMOVE
a9fe5928	458
d6c4a976 DK	459	if ((Flags & Moveable) == Moveable)
	460	Base = mremap(Base, WorkSpace, newSize, MREMAP_MAYMOVE);
	461	else
	462	#endif
	463	Base = mremap(Base, WorkSpace, newSize, 0);
f1c6a8ca	464
d6c4a976 DK	465	if(Base == MAP_FAILED)
d6c4a976 DK	466	return false;
f1c6a8ca	467	#else
d6c4a976	468	return false;
f1c6a8ca	469	#endif
d6c4a976 DK	470	} else {
	471	if ((Flags & Moveable) != Moveable)
	472	return false;
	473
	474	Base = realloc(Base, newSize);
	475	if (Base == NULL)
	476	return false;
e3026ce4 JAK	477	else
	478	/* Set new memory to 0 */
	479	memset((char*)Base + WorkSpace, 0, newSize - WorkSpace);
d6c4a976 DK	480	}
d6c4a976 DK	481
a9fe5928	482	Pools =(Pool*) Base + poolOffset;
d6c4a976 DK	483	WorkSpace = newSize;
d6c4a976 DK	484	return true;
f1c6a8ca DK	485	}
f1c6a8ca DK	486	/}}}/