我很确定这是一个简单的问题,但我不知道socket.io文档在哪里,而http://labs.learnboost.com/socket.io/上的文件并没有真正帮助.
所以,假设我有一个socket.io http服务器并编写了一个网站来连接它.
如何为服务器提供保护,以便阻止/删除/禁止未经授权的人(不通过网站连接的人).
如何在服务器端结束套接字连接?所以,如果我有
io.sockets.on('connection', function (socket) {
socket.on('end', function() {
var i = global_sockets_list.indexOf(socket);
global_sockets_list.splice(i, 1);
});
socket.emit('end'); // Doesn't work, just sends data
socket.end(); //error
});
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使用Django 1.5.1.Python 2.7.3.
我想用外键字段和段塞字段做一个唯一的约束约束.所以在我的模型元中,我做到了
foreign_key = models.ForeignKey("self", null=True, default=None)
slug = models.SlugField(max_length=40, unique=False)
class Meta:
unique_together = ("foreign_key", "slug")
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我甚至检查了Postgres(9.1)中的表描述,并将约束放入数据库表中.
-- something like
"table_name_foreign_key_id_slug_key" UNIQUE CONSTRAINT, btree (foreign_key_id, slug)
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但是,我仍然可以在数据库表中保存None/null的foreign_key和重复的字符串.
例如,
我可以输入并保存
# model objects with slug="python" three times; all three foreign_key(s)
# are None/null because that is their default value
MO(slug="python").save()
MO(slug="python").save()
MO(slug="python").save()
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所以在使用unique_together之后,为什么我仍然可以输入三个相同值的行?
我现在只是猜测它可能与foreign_key字段的默认值None有关,因为在unique_together之前,当我在slug上有unique = True时,一切正常.因此,如果是这种情况,我应该具有哪个默认值表示空值,还保持唯一约束?
我在for-loop中创建子进程.在子进程内部,我可以检索子PID getpid().
但是,出于某种原因,当我尝试将值存储getpid()到父进程声明的变量中时,当我在父进程中检查它时,更改无效.我假设这与某种过程变量范围有关.不太熟悉C,所以不能太确定.
无论如何,什么是将getpid()子PID 的结果(当从子进程调用时)存储到父进程中的变量的方法?
或者也许另一种方法是存储fork()到父变量中并调用该变量上的某个函数来检索子节点的PID?我不知道怎么做,所以如果这是更好的方法,你会怎么做?
我是mongoose/mongodb的新手
说我保存了一些东西:
var instance = new TestingModel();
instance.test = 'blah2';
instance.save();
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因此,当我保存数据库中的实例obj将具有,_id和test时.但只有在进入db后才会将_id属性添加到对象中.注意:我之前不想给它一个id.但是,我想抓住数据库中的对象,因为我需要使用_id值,但我不想再次查询它.有没有办法将对象保存在数据库中并自动返回数据库对象,以便获取_id值?
我正在考虑使用node.js/socket.io做一个聊天服务器.我应该将其设为tcp服务器还是http服务器?我想tcp服务器会更有效率,但你可以像文件附件一样发送其他东西吗?如果tcp效率更高,那还有多少呢?还想知道一个node.js服务器可以处理多少个并发连接?做TCP或HTTP更多的工作吗?
我正在阅读Django bulk_create及其一些"缺陷":
"
This has a number of caveats though:
1. The model's save() method will not be called, and the pre_save and post_save signals will not be sent.
2. It does not work with child models in a multi-table inheritance scenario.
3. If the model's primary key is an AutoField it does not retrieve and set the primary key attribute, as save() does.
"
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我没有完全理解它.所以,如果我有一个对象列表,请将其传递给bulk_create:
objList = [a, b, c,] #none are saved
model.objects.bulk_create(objList)
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我还能在外键中使用这些对象吗?
for obj in objList: …Run Code Online (Sandbox Code Playgroud) 使用ubuntu 12.04
cordova platform add android
Creating android project...
/usr/local/lib/node_modules/cordova/node_modules/q/q.js:126
throw e;
^
Error: An error occured during creation of android sub-project.
/home/admin/.cordova/lib/android/cordova/3.3.0/bin/node_modules/q/q.js:126
throw e;
^
Error: An error occurred while listing Android targets
at /home/admin/.cordova/lib/android/cordova/3.3.0/bin/lib/check_reqs.js:87:29
at _rejected (/home/admin/.cordova/lib/android/cordova/3.3.0/bin/node_modules/q/q.js:808:24)
at /home/admin/.cordova/lib/android/cordova/3.3.0/bin/node_modules/q/q.js:834:30
at Promise.when (/home/admin/.cordova/lib/android/cordova/3.3.0/bin/node_modules/q/q.js:1079:31)
at Promise.promise.promiseDispatch (/home/admin/.cordova/lib/android/cordova/3.3.0/bin/node_modules/q/q.js:752:41)
at /home/admin/.cordova/lib/android/cordova/3.3.0/bin/node_modules/q/q.js:574:44
at flush (/home/admin/.cordova/lib/android/cordova/3.3.0/bin/node_modules/q/q.js:108:17)
at process._tickCallback (node.js:415:13)
at /usr/local/lib/node_modules/cordova/src/platform.js:244:30
at ChildProcess.exithandler (child_process.js:641:7)
at ChildProcess.EventEmitter.emit (events.js:98:17)
at maybeClose (child_process.js:735:16)
at Socket.<anonymous> (child_process.js:948:11)
at Socket.EventEmitter.emit (events.js:95:17)
at Pipe.close (net.js:466:12)
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我究竟做错了什么?
我试过这样做:
package main
import (
"fmt"
"strings"
)
type String string
func (s *String) tolower() String {
*s = String(strings.ToLower(string(*s)))
return *s
}
func (s *String) toupper() String {
*s = String(strings.ToUpper(string(*s)))
return *s
}
func main() {
var s String = "ASDF"
(s.tolower()).toupper() // this fails
// s.toupper();s.tolower(); // this works
// s.tolower().toupper() // this fails too
fmt.Println(s)
}
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但我得到了这些错误:
prog.go:30: cannot call pointer method on s.tolower()
prog.go:30: cannot take the address of s.tolower()
Program exited.
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为什么我不能让这个链条工作?
使用python3.4w/pip尝试安装django-floppyforms==1.1并获得此功能non-ASCII payload error.我没有得到这个错误python2.7.这是怎么回事?
Downloading/unpacking django-floppyforms==1.1 (from -r ../requirements/base.txt (line 22))
Downloading django_floppyforms-1.1-py33-none-any.whl (51kB): 51kB downloaded
Cleaning up...
Exception:
Traceback (most recent call last):
File "/home/admin/.virtualenvs/py3/lib/python3.4/site-packages/pip/basecommand.py", line 122, in main
status = self.run(options, args)
File "/home/admin/.virtualenvs/py3/lib/python3.4/site-packages/pip/commands/install.py", line 274, in run
requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
File "/home/admin/.virtualenvs/py3/lib/python3.4/site-packages/pip/req.py", line 1206, in prepare_files
for subreq in dist.requires(req_to_install.extras):
File "/home/admin/.virtualenvs/py3/lib/python3.4/site-packages/pip/_vendor/pkg_resources.py", line 2236, in requires
dm = self._dep_map
File "/home/admin/.virtualenvs/py3/lib/python3.4/site-packages/pip/_vendor/pkg_resources.py", line 2429, in _dep_map
self.__dep_map = self._compute_dependencies() …Run Code Online (Sandbox Code Playgroud)