libc6 generates warnings -- which should be errors, g++ isn't properly
strict.
- The configure test notes that some OS's have broken private mmap's
- so on those OS's we can't use mmap. This means we have to use
- configure to test mmap and can't rely on the POSIX
- _POSIX_MAPPED_FILES test.
-
##################################################################### */
/*}}}*/
// Include Files /*{{{*/
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
+#include <stdlib.h>
#include <cstring>
/*}}}*/
}
/*}}}*/
+ /*}}}*/
// DynamicMMap::DynamicMMap - Constructor /*{{{*/
// ---------------------------------------------------------------------
/* */
-DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long WorkSpace) :
+DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long WorkSpace) :
MMap(F,Flags | NoImmMap), Fd(&F), WorkSpace(WorkSpace)
{
if (_error->PendingError() == true)
/*}}}*/
// DynamicMMap::DynamicMMap - Constructor for a non-file backed map /*{{{*/
// ---------------------------------------------------------------------
-/* This is just a fancy malloc really.. */
+/* 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 WorkSpace) :
MMap(Flags | NoImmMap | UnMapped), Fd(0), WorkSpace(WorkSpace)
{
if (_error->PendingError() == true)
return;
-
+
+#ifdef _POSIX_MAPPED_FILES
+ // use anonymous mmap() to get the memory
+ Base = (unsigned char*) mmap(0, WorkSpace, PROT_READ|PROT_WRITE,
+ MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+ if(Base == MAP_FAILED)
+ return;
+#else
+ // fallback to a static allocated space
Base = new unsigned char[WorkSpace];
memset(Base,0,WorkSpace);
+#endif
iSize = 0;
}
/*}}}*/
{
if (Fd == 0)
{
+#ifdef _POSIX_MAPPED_FILES
+ if(munmap(Base, WorkSpace) < 0)
+#else
delete [] (unsigned char *)Base;
+#endif
return;
}
unsigned long Result = iSize;
if (Aln != 0)
Result += Aln - (iSize%Aln);
-
+
iSize = Result + Size;
-
- // Just in case error check
- if (Result + Size > WorkSpace)
+
+ // try to grow the buffer
+ while(Result + Size > WorkSpace)
{
- _error->Error(_("Dynamic MMap ran out of room. Please increase the size "
- "of APT::Cache-Limit. Current value: %lu. (man 5 apt.conf)"), WorkSpace);
- return 0;
+ if(!Grow())
+ {
+ _error->Error(_("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;
}
/*}}}*/
/* 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;
if (I->ItemSize == ItemSize)
break;
}
-
// No pool is allocated, use an unallocated one
if (I == Pools + PoolCount)
{
I->ItemSize = ItemSize;
I->Count = 0;
}
-
+
+ unsigned long Result = 0;
// Out of space, allocate some more
if (I->Count == 0)
{
- I->Count = 20*1024/ItemSize;
- I->Start = RawAllocate(I->Count*ItemSize,ItemSize);
- }
+ const unsigned long size = 20*1024;
+ I->Count = size/ItemSize;
+ Result = RawAllocate(size,ItemSize);
+ // Does the allocation failed ?
+ if (Result == 0 && _error->PendingError())
+ return 0;
+ I->Start = Result;
+ }
+ else
+ Result = I->Start;
I->Count--;
- unsigned long Result = I->Start;
- I->Start += ItemSize;
+ I->Start += ItemSize;
return Result/ItemSize;
}
/*}}}*/
unsigned long DynamicMMap::WriteString(const char *String,
unsigned long Len)
{
- unsigned long Result = iSize;
- // Just in case error check
- if (Result + Len > WorkSpace)
- {
- _error->Error(_("Dynamic MMap ran out of room. Please increase the size "
- "of APT::Cache-Limit. Current value: %lu. (man 5 apt.conf)"), WorkSpace);
- return 0;
- }
-
if (Len == (unsigned long)-1)
Len = strlen(String);
- iSize += Len + 1;
+
+ unsigned long 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 will try to grow the mmap we currently use. This doesn't
+ work most of the time because we can't move the mmap around in the
+ memory for now as this would require to adjust quite a lot of pointers
+ but why we should not at least try to grow it before we give up? */
+bool DynamicMMap::Grow()
+{
+#ifdef _POSIX_MAPPED_FILES
+ unsigned long newSize = WorkSpace + 1024*1024;
+
+ if(Fd != 0)
+ {
+ Fd->Seek(newSize - 1);
+ char C = 0;
+ Fd->Write(&C,sizeof(C));
+ }
+
+ Base = mremap(Base, WorkSpace, newSize, 0);
+ if(Base == MAP_FAILED)
+ return false;
+
+ WorkSpace = newSize;
+ return true;
+#else
+ return false;
+#endif
+}
+ /*}}}*/
projects / apt.git / blobdiff