block

Is it possible to block the installation of a package on a Honeycomb device? What I'd like to have is an application (or service or everything) that, once running, it inhibits subsequent installation of other packages. Let's suppose to be a service. While it runs, if the device user attempts an installation by the Market, it will be aborted. It is possible (continue supposing) to register an APPLICATION_IS_ABOUT_TO_BE_INSTALLED broadcast receiver that can break the PackageManager process? Thanks in advance L. Nopes ! AFAIK, Not possible yet ! 来源： https://stackoverflow.com/questions/6411031

1、概述 hdfs文件系统主要设计为了存储大文件的文件系统；如果有个TB级别的文件，我们该怎么存储呢？分布式文件系统未出现的时候，一个文件只能存储在个服务器上，可想而知，单个服务器根本就存储不了这么大的文件；退而求其次，就算一个服务器可以存储这么大的文件，你如果想打开这个文件，效率会高吗 hdfs的出现就是为了解决上面的问题 hdfs为了满足大文件的存储和可读性，对数据进行切成多个小块进行存储，同时为了保证数据的可靠性，又对每个小块数据做复制，然后分别存储到多个节点中 hdfs2.7.3后，默认每个块的大小是128MB，在hdfs1.0的时候，默认每个块的大小是64MB 可以通过修改hdfs的配置文件自定义块大小 hdfs-site.xml文件中的dfs.blocksize 默认每个块的副本数是3，可以通过修改hdfs的配置文件自定义副本数 hdfs-site.xml的dfs.replication 二、hdfs的结构体系 hdfs是一个分布式的文件系统，采用主从（master/slave）的结构体系，一个hdfs集群由NameNode和多个datanode组成，其中namenode作为主节点，DataNode为从节点 Namenode简称NN DataNode简称DN NN的作用 a、存储元数据信息 b、元数据存储两份，一份在内存中，一份在硬盘中 c、保存文件、block

I have the following function in Python that seems to be working: def test(self): x = -1 # why don't I need to initialize y = 0 here? if (x < 0): y = 23 return y But for this to work why don't I need to initialize variable y? I thought Python had block scope so how is this possible? wim This appears to be a simple misunderstanding about scope in Python . Conditional statements don't create a scope. The name y is in the local scope inside the function, because of this statement which is present in the syntax tree: y = 23 This is determined at function definition time, when the function is

Before/After call the block, the retaincount is always 1. From apple block doc we know that the self should retain. Can anyone know why? NSLog(@"Before block retain count: %d", [self retainCount]); void (^block)(void) = ^(void){ UIImage* img = [UIImage imageNamed:@"hometown.png"]; [self setImage:img]; NSLog(@"After block retain count: %d", [self retainCount]); }; block(); First, retainCount is useless. Don't call it. . Blocks only retain captured objects when the block is copied. Thus, self won't be retained by the block in that example. OK I did some research, now things became more clear.

What is wrong in the code? def call_block(n) if n==1 return 0 elsif n== 2 return 1 else yield return call_block(n-1) + call_block(n-2) end end puts call_block(10) {puts "Take this"} I am trying to use yield to print Take this other than the tenth fibonacci number. I am getting the error: in `call_block': no block given (LocalJumpError) Even the following code throws error: def call_block(n) if n==1 yield return 0 elsif n== 2 yield return 1 else yield return call_block(n-1) + call_block(n-2) end end puts call_block(10) {puts "Take this"} yfeldblum You might want to use this line, as Adam

liunx 使用ext2 的文件系统的管理方式： liunx 主要使用 superblock、inode，bolck的方式去管理文件系统 inode：主要存储各个文件的所有者，以及相应的权限，文件信息 block：实际文件二进制的内容存储 superblock：记录inode的使用量，block的文件使用量，等 那ext2最简单的方式是 一个文件或者目录使用一个inode，这个inode大概有128字节。其中48个字节用来存储它保存的实际文件的block节点，保存一个block的需要4字节的大小，所以48字节可以保存12个block 一个block可以设置为的大小为1k,2K，4k大小 当我们常见一个文件或者目录的时候，使用一个inode，并且分配好block来保存文件内容，但是一个inode仅仅可以保存12个block，一个block假设最大设置为4K，那么一个文件也不过保存了 12*4 = 48k的大小 根本保存不了我们平常见到的100多m的文件，那么ext2怎么解决这个问题呢，很简单，在使用一个block来保存，另外的block地址，就跟俄罗斯套娃一样，第一层block保存第二层的block的地址，那么第二层就实际可以保存，假设一个block的大小为 1k，那么可以保存 1024 / 4 = 256个第二层block的信息，如果每一层都使用用来保存新一层的信息

I have a method which looks like this: -(NSString *)getCityFromLocation:(CLLocation *)location { __block NSString *city; CLGeocoder *geocoder = [[CLGeocoder alloc] init]; [geocoder reverseGeocodeLocation: location completionHandler: ^(NSArray *placemarks, NSError *error) { //Get address CLPlacemark *placemark = [placemarks objectAtIndex:0]; city = [placemark.addressDictionary objectForKey:@"City"]; NSLog(@"city 1: %@", city); }]; return city; } And I call it like this: NSString *city = [self getCityFromLocation:currentLocation]; NSLog(@"city 2: %@", city); In NSLog, I get: city 2: (null) city

There is an example of javascript blocking from Steve Souders from his Book 'High Performance Web Sites': http://stevesouders.com/hpws/js-blocking.php Javascripts don't block Downloads anymore, but still do block rendering. .. but there is a strange download activity: There are 5 parallel downloads (max 6 are possible in Firefox 3 or IE 8 from the same server/host) 4 Images (2 from host1, 2 from host2) 1 Javascript in between there is also a 5th image in the page, but the loading of this fifth image does not occure in parallel, but only after Javascript has finished loading. so why does that