Hbase_shell底层源码乱砍乱伐--59

大约10个月没有更新博客了，一直在学习新的东西，忙的不可开胶，现在一边整理做过的事情，以便复习一下。白天要工作也只有后半夜才有时间看书了。------青春无悔

下面的代码是关于Hbase shell脚本的源码的改写，屏蔽了一些功能，便于理解和安全操作。

现在没时间逐一解释关键点的含义，以后有时间再改，替换掉集群中：hbase_home:/lib/ruby/shell.rb

# Shell commands module
module Shell
@@commands = {}
def self.commands
@@commands
end

@@command_groups = {}
def self.command_groups
@@command_groups
end

def self.load_command(name, group, aliases=[])
return if commands[name]

# Register command in the group
raise ArgumentError, "Unknown group: #{group}" unless command_groups[group]
command_groups[group][:commands] << name

# Load command
begin
require "shell/commands/#{name}"
klass_name = name.to_s.gsub(/(?:^|_)(.)/) { $1.upcase } # camelize
commands[name] = eval("Commands::#{klass_name}")
aliases.each do |an_alias|
commands[an_alias] = commands[name]
end
rescue => e
raise "Can't load hbase shell command: #{name}. Error: #{e}\n#{e.backtrace.join("\n")}"
end
end

def self.load_command_group(group, opts)
raise ArgumentError, "No :commands for group #{group}" unless opts[:commands]

command_groups[group] = {
:commands => [],
:command_names => opts[:commands],
:full_name => opts[:full_name] || group,
:comment => opts[:comment]
}

all_aliases = opts[:aliases] || {}

opts[:commands].each do |command|
aliases = all_aliases[command] || []
load_command(command, group, aliases)
end
end

#----------------------------------------------------------------------
class Shell
attr_accessor :hbase
attr_accessor :formatter
attr_accessor :interactive
alias interactive? interactive

@debug = false
attr_accessor :debug

def initialize(hbase, formatter, interactive=true)
self.hbase = hbase
self.formatter = formatter
self.interactive = interactive
end

def hbase_admin
@hbase_admin ||= hbase.admin(formatter)
end

def hbase_table(name)
hbase.table(name, self)
end

def hbase_replication_admin
@hbase_replication_admin ||= hbase.replication_admin(formatter)
end

def hbase_security_admin
@hbase_security_admin ||= hbase.security_admin(formatter)
end

def hbase_visibility_labels_admin
@hbase_visibility_labels_admin ||= hbase.visibility_labels_admin(formatter)
end

def hbase_quotas_admin
@hbase_quotas_admin ||= hbase.quotas_admin(formatter)
end

def export_commands(where)
::Shell.commands.keys.each do |cmd|
# here where is the IRB namespace
# this method just adds the call to the specified command
# which just references back to 'this' shell object
# a decently extensible way to add commands
where.send :instance_eval, <<-EOF
def #{cmd}(*args)
ret = @shell.command('#{cmd}', *args)
puts
return ret
end
EOF
end
end

def command_instance(command)
::Shell.commands[command.to_s].new(self)
end

#call the method 'command' on the specified command
def command(command, *args)
internal_command(command, :command, *args)
end

#call a specific internal method in the command instance
# command  - name of the command to call
# method_name - name of the method on the command to call. Defaults to just 'command'
# args - to be passed to the named method
def internal_command(command, method_name= :command, *args)
command_instance(command).command_safe(self.debug,method_name, *args)
end

def print_banner
puts "HBase Shell; enter 'help<RETURN>' for list of supported commands."
puts 'Type "exit<RETURN>" to leave the HBase Shell'
print 'Version '
command('version')
puts
end

def help_multi_command(command)
puts "Command: #{command}"
puts command_instance(command).help
puts
return nil
end

def help_command(command)
puts command_instance(command).help
return nil
end

def help_group(group_name)
group = ::Shell.command_groups[group_name.to_s]
group[:commands].sort.each { |cmd| help_multi_command(cmd) }
if group[:comment]
puts '-' * 80
puts
puts group[:comment]
puts
end
return nil
end

def help(command = nil)
if command
return help_command(command) if ::Shell.commands[command.to_s]
return help_group(command) if ::Shell.command_groups[command.to_s]
puts "ERROR: Invalid command or command group name: #{command}"
puts
end

puts help_header
puts
puts 'COMMAND GROUPS:'
::Shell.command_groups.each do |name, group|
puts "  Group name: " + name
puts "  Commands: " + group[:command_names].sort.join(', ')
puts
end
unless command
puts 'SHELL USAGE:'
help_footer
end
return nil
end

def help_header
return "HBase Shell, version #{org.apache.hadoop.hbase.util.VersionInfo.getVersion()}, " +
"r#{org.apache.hadoop.hbase.util.VersionInfo.getRevision()}, " +
"#{org.apache.hadoop.hbase.util.VersionInfo.getDate()}" + "\n" +
"Type 'help \"COMMAND\"', (e.g. 'help \"get\"' -- the quotes are necessary) for help on a specific command.\n" +
"Commands are grouped. Type 'help \"COMMAND_GROUP\"', (e.g. 'help \"general\"') for help on a command group."
end

def help_footer
puts <<-HERE
Quote all names in HBase Shell such as table and column names.  Commas delimit
command parameters.  Type <RETURN> after entering a command to run it.
Dictionaries of configuration used in the creation and alteration of tables are
Ruby Hashes. They look like this:

{'key1' => 'value1', 'key2' => 'value2', ...}

and are opened and closed with curley-braces.  Key/values are delimited by the
'=>' character combination.  Usually keys are predefined constants such as
NAME, VERSIONS, COMPRESSION, etc.  Constants do not need to be quoted.  Type
'Object.constants' to see a (messy) list of all constants in the environment.

If you are using binary keys or values and need to enter them in the shell, use
double-quote'd hexadecimal representation. For example:

hbase> get 't1', "key\\x03\\x3f\\xcd"
hbase> get 't1', "key\\003\\023\\011"
hbase> put 't1', "test\\xef\\xff", 'f1:', "\\x01\\x33\\x40"

The HBase shell is the (J)Ruby IRB with the above HBase-specific commands added.
For more on the HBase Shell, see http://hbase.apache.org/book.html HERE
end
end
end

# Load commands base class
require 'shell/commands'

# Load all commands
Shell.load_command_group(
'general',
:full_name => 'GENERAL HBASE SHELL COMMANDS',
:commands => %w[
version
whoami
]
)

Shell.load_command_group(
'ddl',
:full_name => 'TABLES MANAGEMENT COMMANDS',
:commands => %w[
describe
exists
list
],
:aliases => {
'describe' => ['desc']
}
)

Shell.load_command_group(
'namespace',
:full_name => 'NAMESPACE MANAGEMENT COMMANDS',
:commands => %w[
]
)

Shell.load_command_group(
'dml',
:full_name => 'DATA MANIPULATION COMMANDS',
:commands => %w[
count
get
scan
]
)

Shell.load_command_group(
'tools',
:full_name => 'HBASE SURGERY TOOLS',
:comment => "WARNING: Above commands are for 'experts'-only as misuse can damage an install",
:commands => %w[
]
)

Shell.load_command_group(
'replication',
:full_name => 'CLUSTER REPLICATION TOOLS',
:comment => "In order to use these tools, hbase.replication must be true.",
:commands => %w[
]
)

Shell.load_command_group(
'snapshots',
:full_name => 'CLUSTER SNAPSHOT TOOLS',
:commands => %w[
]
)

Shell.load_command_group(
'configuration',
:full_name => 'ONLINE CONFIGURATION TOOLS',
:commands => %w[
]
)

Shell.load_command_group(
'quotas',
:full_name => 'CLUSTER QUOTAS TOOLS',
:commands => %w[
]
)

Shell.load_command_group(
'security',
:full_name => 'SECURITY TOOLS',
:comment => "NOTE: Above commands are only applicable if running with the AccessController coprocessor",
:commands => %w[
]
)

Shell.load_command_group(
'visibility labels',
:full_name => 'VISIBILITY LABEL TOOLS',
:comment => "NOTE: Above commands are only applicable if running with the VisibilityController coprocessor",
:commands => %w[
]
)