Class FSTableDescriptors

java.lang.Object
org.apache.hadoop.hbase.util.FSTableDescriptors
All Implemented Interfaces:
Closeable, AutoCloseable, TableDescriptors

@Private public class FSTableDescriptors extends Object implements TableDescriptors
Implementation of TableDescriptors that reads descriptors from the passed filesystem. It expects descriptors to be in a file in the TABLEINFO_DIR subdir of the table's directory in FS. Can be read-only -- i.e. does not modify the filesystem or can be read and write.

Also has utility for keeping up the table descriptors tableinfo file. The table schema file is kept in the TABLEINFO_DIR subdir of the table directory in the filesystem. It has a TABLEINFO_FILE_PREFIX and then a suffix that is the edit sequenceid: e.g. .tableinfo.0000000003. This sequenceid is always increasing. It starts at zero. The table schema file with the highest sequenceid has the most recent schema edit. Usually there is one file only, the most recent but there may be short periods where there are more than one file. Old files are eventually cleaned. Presumption is that there will not be lots of concurrent clients making table schema edits. If so, the below needs a bit of a reworking and perhaps some supporting api in hdfs.