Python set_advice示例

示例#1

from datetime import timedelta

SAME = b"0"
DIFF = b"1"
COMPLEN = len(SAME)  # SAME/DIFF length

LOCAL_FADVISE = 1
REMOTE_FADVISE = 2

if callable(getattr(os, "posix_fadvise", False)):
    from os import posix_fadvise, POSIX_FADV_NOREUSE, POSIX_FADV_DONTNEED
    fadvise = lambda fileobj, offset, length, advice: posix_fadvise(fileobj.fileno(), offset, length, advice)
else:
    try:
        from fadvise import set_advice, POSIX_FADV_NOREUSE, POSIX_FADV_DONTNEED
        fadvise = lambda fileobj, offset, length, advice: set_advice(fileobj, advice, offset, length)
    except:
        fadvise = None

if fadvise:
    USE_DONTNEED = sys.platform.startswith('linux')
    USE_NOREUSE = not(USE_DONTNEED)
else:
    USE_NOREUSE = USE_DONTNEED = False

def do_create(f, size):
    f = open(f, 'a', 0)
    f.truncate(size)
    f.close()

示例#2

文件： blocksync.py 项目： ct16k/blocksync

from datetime import timedelta

SAME = b"0"
DIFF = b"1"
COMPLEN = len(SAME)  # SAME/DIFF length

LOCAL_FADVISE = 1
REMOTE_FADVISE = 2

if callable(getattr(os, "posix_fadvise", False)):
    from os import posix_fadvise, POSIX_FADV_NOREUSE, POSIX_FADV_DONTNEED
    fadvise = lambda fileobj, offset, length, advice: posix_fadvise(fileobj.fileno(), offset, length, advice)
else:
    try:
        from fadvise import set_advice, POSIX_FADV_NOREUSE, POSIX_FADV_DONTNEED
        fadvise = lambda fileobj, offset, length, advice: set_advice(fileobj, advice, offset, length)
    except:
        fadvise = None

if fadvise:
    USE_DONTNEED = sys.platform.startswith('linux')
    USE_NOREUSE = not(USE_DONTNEED)
else:
    USE_NOREUSE = USE_DONTNEED = False

def do_create(f, size):
    f = open(f, 'a', 0)
    f.truncate(size)
    f.close()