我写了一个Nautilus扩展,它读取图片的元数据(执行exiftool
),但是当我打开包含许多文件的文件夹时,它确实会减慢文件管理器的速度,并挂起,直到读取完文件的数据。
有没有办法让鹦鹉螺在运行我的分机时继续工作?也许EXIF数据可以逐渐出现在列中,而我继续我的工作。
#!/usr/bin/python
# Richiede:
# nautilus-python
# exiftool
# gconf-python
# Versione 0.15
import gobject
import nautilus
from subprocess import Popen, PIPE
from urllib import unquote
import gconf
def getexiftool(filename):
options = '-fast2 -f -m -q -q -s3 -ExifIFD:DateTimeOriginal -IFD0:Software -ExifIFD:Flash -Composite:ImageSize -IFD0:Model'
exiftool=Popen(['/usr/bin/exiftool'] + options.split() + [filename],stdout=PIPE,stderr=PIPE)
#'-Nikon:ShutterCount' non utilizzabile con l'argomento -fast2
output,errors=exiftool.communicate()
return output.split('\n')
class ColumnExtension(nautilus.ColumnProvider, nautilus.InfoProvider, gobject.GObject):
def __init__(self):
pass
def get_columns(self):
return (
nautilus.Column("NautilusPython::ExifIFD:DateTimeOriginal","ExifIFD:DateTimeOriginal","Data (ExifIFD)","Data di scatto"),
nautilus.Column("NautilusPython::IFD0:Software","IFD0:Software","Software (IFD0)","Software utilizzato"),
nautilus.Column("NautilusPython::ExifIFD:Flash","ExifIFD:Flash","Flash (ExifIFD)","Modalit\u00e0 del flash"),
nautilus.Column("NautilusPython::Composite:ImageSize","Composite:ImageSize","Risoluzione (Exif)","Risoluzione dell'immagine"),
nautilus.Column("NautilusPython::IFD0:Model","IFD0:Model","Fotocamera (IFD0)","Modello fotocamera"),
#nautilus.Column("NautilusPython::Nikon:ShutterCount","Nikon:ShutterCount","Contatore scatti (Nikon)","Numero di scatti effettuati dalla macchina a questo file"),
nautilus.Column("NautilusPython::Mp","Mp","Megapixel (Exif)","Dimensione dell'immagine in megapixel"),
)
def update_file_info_full(self, provider, handle, closure, file):
client = gconf.client_get_default()
if not client.get_bool('/apps/nautilus/nautilus-metadata/enable'):
client.set_bool('/apps/nautilus/nautilus-metadata/enable',0)
return
if file.get_uri_scheme() != 'file':
return
if file.get_mime_type() in ('image/jpeg', 'image/png', 'image/gif', 'image/bmp', 'image/x-nikon-nef', 'image/x-xcf', 'image/vnd.adobe.photoshop'):
gobject.timeout_add_seconds(1, self.update_exif, provider, handle, closure, file)
return Nautilus.OperationResult.IN_PROGRESS
file.add_string_attribute('ExifIFD:DateTimeOriginal','')
file.add_string_attribute('IFD0:Software','')
file.add_string_attribute('ExifIFD:Flash','')
file.add_string_attribute('Composite:ImageSize','')
file.add_string_attribute('IFD0:Model','')
file.add_string_attribute('Nikon:ShutterCount','')
file.add_string_attribute('Mp','')
return Nautilus.OperationResult.COMPLETE
def update_exif(self, provider, handle, closure, file):
filename = unquote(file.get_uri()[7:])
data = getexiftool(filename)
file.add_string_attribute('ExifIFD:DateTimeOriginal',data[0].replace(':','-',2))
file.add_string_attribute('IFD0:Software',data[1])
file.add_string_attribute('ExifIFD:Flash',data[2])
file.add_string_attribute('Composite:ImageSize',data[3])
file.add_string_attribute('IFD0:Model',data[4])
#file.add_string_attribute('Nikon:ShutterCount',data[5])
width, height = data[3].split('x')
mp = float(width) * float(height) / 1000000
mp = "%.2f" % mp
file.add_string_attribute('Mp',str(mp) + ' Mp')
Nautilus.info_provider_update_complete_invoke(closure, provider, handle, Nautilus.OperationResult.COMPLETE)
return false
最佳答案
这是因为您正在调用update_file_info,它是Nautilus异步IO系统的一部分。因此,如果行动不够快,它会阻止鹦鹉螺。
在您的情况下,这会加剧,因为您正在调用一个外部程序,这是一个昂贵的操作。注意,每个文件调用一次update_file_info。如果您有100个文件,那么您将调用100次外部程序,Nautilus将不得不在处理下一个文件之前等待每一个文件。
由于nautilus python 0.7提供了update_file_info_full和cancel_update,这允许您编程异步调用。您可以查看documentation of Nautilus 0.7 for more details。
值得一提的是,这只是nautilus python的一个限制,它以前没有公开C中可用的那些方法。
编辑:增加了几个例子。
诀窍是使进程尽可能快或使其异步。
示例1:调用外部程序
使用代码的简化版本,我们使用
GObject.timeout_在更新文件信息中添加秒数已满。
from gi.repository import Nautilus, GObject
from urllib import unquote
from subprocess import Popen, PIPE
def getexiftool(filename):
options = '-fast2 -f -m -q -q -s3 -ExifIFD:DateTimeOriginal'
exiftool = Popen(['/usr/bin/exiftool'] + options.split() + [filename],
stdout=PIPE, stderr=PIPE)
output, errors = exiftool.communicate()
return output.split('\n')
class MyExtension(Nautilus.ColumnProvider, Nautilus.InfoProvider, GObject.GObject):
def __init__(self):
pass
def get_columns(self):
return (
Nautilus.Column(name='MyExif::DateTime',
attribute='Exif:Image:DateTime',
label='Date Original',
description='Data time original'
),
)
def update_file_info_full(self, provider, handle, closure, file_info):
if file_info.get_uri_scheme() != 'file':
return
filename = unquote(file_info.get_uri()[7:])
attr = ''
if file_info.get_mime_type() in ('image/jpeg', 'image/png'):
GObject.timeout_add_seconds(1, self.update_exif,
provider, handle, closure, file_info)
return Nautilus.OperationResult.IN_PROGRESS
file_info.add_string_attribute('Exif:Image:DateTime', attr)
return Nautilus.OperationResult.COMPLETE
def update_exif(self, provider, handle, closure, file_info):
filename = unquote(file_info.get_uri()[7:])
try:
data = getexiftool(filename)
attr = data[0]
except:
attr = ''
file_info.add_string_attribute('Exif:Image:DateTime', attr)
Nautilus.info_provider_update_complete_invoke(closure, provider,
handle, Nautilus.OperationResult.COMPLETE)
return False
上面的代码不会阻止Nautilus,如果列视图中有“Date Original”列,JPEG和PNG图像将显示“unknown”值,并且它们将缓慢更新(1秒后调用子进程)。
示例2:使用库
与其调用外部程序,不如使用库。如下例:
from gi.repository import Nautilus, GObject
from urllib import unquote
import pyexiv2
class MyExtension(Nautilus.ColumnProvider, Nautilus.InfoProvider, GObject.GObject):
def __init__(self):
pass
def get_columns(self):
return (
Nautilus.Column(name='MyExif::DateTime',
attribute='Exif:Image:DateTime',
label='Date Original',
description='Data time original'
),
)
def update_file_info_full(self, provider, handle, closure, file_info):
if file_info.get_uri_scheme() != 'file':
return
filename = unquote(file_info.get_uri()[7:])
attr = ''
if file_info.get_mime_type() in ('image/jpeg', 'image/png'):
metadata = pyexiv2.ImageMetadata(filename)
metadata.read()
try:
tag = metadata['Exif.Image.DateTime'].value
attr = tag.strftime('%Y-%m-%d %H:%M')
except:
attr = ''
file_info.add_string_attribute('Exif:Image:DateTime', attr)
return Nautilus.OperationResult.COMPLETE
最后,如果例程很慢,则需要使其异步(可能使用比GObject.timeout_add_seconds更好的方法)。
最后但并非最不重要的是,在我的示例中,我使用了GObject内省(通常用于Nautilus 3),但是很容易将其更改为直接使用模块Nautilus。