3种形式的元数据，fsimage是在磁盘上，meta.data是在内存上，
我们继续，前面呢，断点是打在这一行代码处，
FileSystem fs = FileSystem.get(conf);
weekend110的hdfs下载数据源码跟踪铺垫 + hdfs下载数据源码分析-getFileSystem
现在，开始weekend110的hdfs源码跟踪之打开输入流
1、 清掉之前，所有的断点，
dfs是fs的成员，
此刻，断点过不去了，为什么？因为，这需要在服务器上运行。
由此可见,newInfo里面就是block信息。
LocatedBlocks{
fileLength=143588167
underConstruction=false
blocks=[LocatedBlock{BP-168439838-192.168.80.110-1468829197712:blk_1073741856_1032; getBlockSize()=134217728; corrupt=false; offset=0; locs=[192.168.80.110:50010]}, LocatedBlock{BP-168439838-192.168.80.110-1468829197712:blk_1073741857_1033; getBlockSize()=9370439; corrupt=false; offset=134217728; locs=[192.168.80.110:50010]}]
lastLocatedBlock=LocatedBlock{BP-168439838-192.168.80.110-1468829197712:blk_1073741857_1033; getBlockSize()=9370439; corrupt=false; offset=134217728; locs=[192.168.80.110:50010]}
isLastBlockComplete=true}
BP-168439838-192.168.80.110-1468829197712
这是机器集群的信息，
[hadoop@weekend110 app]$ cd hadoop-2.4.1/
[hadoop@weekend110 hadoop-2.4.1]$ ll
total 60
drwxr-xr-x. 2 hadoop hadoop 4096 Jul 18 15:48 bin
drwxrwxr-x. 4 hadoop hadoop 4096 Jul 18 20:37 data
drwxr-xr-x. 3 hadoop hadoop 4096 Jun 21 2014 etc
drwxr-xr-x. 2 hadoop hadoop 4096 Jun 21 2014 include
drwxr-xr-x. 3 hadoop hadoop 4096 Jun 21 2014 lib
drwxr-xr-x. 2 hadoop hadoop 4096 Jun 21 2014 libexec
-rw-r--r--. 1 hadoop hadoop 15458 Jun 21 2014 LICENSE.txt
drwxrwxr-x. 3 hadoop hadoop 4096 Jul 22 11:20 logs
-rw-r--r--. 1 hadoop hadoop 101 Jun 21 2014 NOTICE.txt
-rw-r--r--. 1 hadoop hadoop 1366 Jun 21 2014 README.txt
drwxr-xr-x. 2 hadoop hadoop 4096 Jun 21 2014 sbin
drwxr-xr-x. 4 hadoop hadoop 4096 Jun 21 2014 share
[hadoop@weekend110 hadoop-2.4.1]$ clear
[hadoop@weekend110 hadoop-2.4.1]$ cd data/
[hadoop@weekend110 data]$ ll
total 8
drwxrwxr-x. 5 hadoop hadoop 4096 Jul 18 16:15 dfs
drwxr-xr-x. 12 hadoop hadoop 4096 Jul 22 11:20 nm-local-dir
[hadoop@weekend110 data]$ cd dfs/
[hadoop@weekend110 dfs]$ ll
total 12
drwx------. 3 hadoop hadoop 4096 Jul 18 23:07 data
drwxrwxr-x. 3 hadoop hadoop 4096 Jul 18 23:06 name
drwxrwxr-x. 3 hadoop hadoop 4096 Jul 18 23:07 namesecondary
[hadoop@weekend110 dfs]$ cd data/
[hadoop@weekend110 data]$ ll
total 8
drwxrwxr-x. 3 hadoop hadoop 4096 Jul 18 16:14 current
-rw-rw-r--. 1 hadoop hadoop 16 Jul 22 11:19 in_use.lock
[hadoop@weekend110 data]$ cd current/
[hadoop@weekend110 current]$ ll
total 8
drwx------. 4 hadoop hadoop 4096 Jul 22 11:20 BP-168439838-192.168.80.110-1468829197712
-rw-rw-r--. 1 hadoop hadoop 229 Jul 22 11:19 VERSION
[hadoop@weekend110 current]$ cd BP-168439838-192.168.80.110-1468829197712/
[hadoop@weekend110 BP-168439838-192.168.80.110-1468829197712]$ ll
total 12
drwxrwxr-x. 4 hadoop hadoop 4096 Jul 18 23:02 current
-rw-rw-r--. 1 hadoop hadoop 0 Jul 22 11:20 dncp_block_verification.log.curr
-rw-rw-r--. 1 hadoop hadoop 348 Jul 22 11:20 dncp_block_verification.log.prev
drwxrwxr-x. 2 hadoop hadoop 4096 Jul 22 11:19 tmp
[hadoop@weekend110 BP-168439838-192.168.80.110-1468829197712]$ cd current/
[hadoop@weekend110 current]$ ll
total 16
-rw-rw-r--. 1 hadoop hadoop 23 Jul 18 23:02 dfsUsed
drwxrwxr-x. 2 hadoop hadoop 4096 Jul 20 15:20 finalized
drwxrwxr-x. 2 hadoop hadoop 4096 Jul 20 15:20 rbw
-rw-rw-r--. 1 hadoop hadoop 131 Jul 22 11:19 VERSION
[hadoop@weekend110 current]$ cd finalized/
[hadoop@weekend110 finalized]$ ll
total 141340
-rw-rw-r--. 1 hadoop hadoop 134217728 Jul 19 09:59 blk_1073741856
-rw-rw-r--. 1 hadoop hadoop 1048583 Jul 19 09:59 blk_1073741856_1032.meta
-rw-rw-r--. 1 hadoop hadoop 9370439 Jul 19 09:59 blk_1073741857
-rw-rw-r--. 1 hadoop hadoop 73215 Jul 19 09:59 blk_1073741857_1033.meta
-rw-rw-r--. 1 hadoop hadoop 168 Jul 19 13:05 blk_1073741858
-rw-rw-r--. 1 hadoop hadoop 11 Jul 19 13:05 blk_1073741858_1034.meta
-rw-rw-r--. 1 hadoop hadoop 71 Jul 20 15:20 blk_1073741866
-rw-rw-r--. 1 hadoop hadoop 11 Jul 20 15:20 blk_1073741866_1042.meta
[hadoop@weekend110 finalized]$
以上是weekend110的hdfs源码跟踪之打开输入流
下面，继续，weekend110的hdfs源码跟踪之打开输入流总结
本文转自大数据躺过的坑博客园博客，原文链接：http://www.cnblogs.com/zlslch/p/5894914.html，如需转载请自行联系原作者
