jyapayne/Nim
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Do not automatically use MAP_POPULATE for opening mmap files.

Browse source 
Adds use_map_populate keyword to memfiles.open and memfiles.mapMem
to govern MAP_POPULATE use. This is set to false by default.
This commit is contained in:
Nick Greenfield 2014-07-23 11:31:03 -07:00
commit cba75db4e3
1 changed files with 9 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

10
lib/pure/memfiles.nim
View file

@ -36,8 +36,11 @@ type
proc mapMem*(m: var TMemFile, mode: TFileMode = fmRead, proc mapMem*(m: var TMemFile, mode: TFileMode = fmRead,
mappedSize = -1, offset = 0): pointer = mappedSize = -1, offset = 0,
use_map_populate = false): pointer =
var readonly = mode == fmRead var readonly = mode == fmRead
if not use_map_populate:
MAP_POPULATE = 0
when defined(windows): when defined(windows):
result = mapViewOfFileEx( result = mapViewOfFileEx(
m.mapHandle, m.mapHandle,
@ -72,7 +75,8 @@ proc unmapMem*(f: var TMemFile, p: pointer, size: int) =
proc open*(filename: string, mode: TFileMode = fmRead, proc open*(filename: string, mode: TFileMode = fmRead,
mappedSize = -1, offset = 0, newFileSize = -1): TMemFile = mappedSize = -1, offset = 0, newFileSize = -1,
use_map_populate = false): TMemFile =
## opens a memory mapped file. If this fails, ``EOS`` is raised. ## opens a memory mapped file. If this fails, ``EOS`` is raised.
## `newFileSize` can only be set if the file does not exist and is opened ## `newFileSize` can only be set if the file does not exist and is opened
## with write access (e.g., with fmReadWrite). `mappedSize` and `offset` ## with write access (e.g., with fmReadWrite). `mappedSize` and `offset`
@ -94,6 +98,8 @@ proc open*(filename: string, mode: TFileMode = fmRead,
# The file can be resized only when write mode is used: # The file can be resized only when write mode is used:
assert newFileSize == -1 or mode != fmRead assert newFileSize == -1 or mode != fmRead
var readonly = mode == fmRead var readonly = mode == fmRead
if not use_map_populate:
MAP_POPULATE = 0
template rollback = template rollback =
result.mem = nil result.mem = nil