Class: Taps::ClientSession

Inherits:
Object
  • Object
show all
Defined in:
lib/taps/client_session.rb

Defined Under Namespace

Classes: CorruptedData

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(database_url, remote_url, default_chunksize) ⇒ ClientSession

Returns a new instance of ClientSession.



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# File 'lib/taps/client_session.rb', line 14

def initialize(database_url, remote_url, default_chunksize)
	@database_url = database_url
	@remote_url = remote_url
	@default_chunksize = default_chunksize
end

Instance Attribute Details

#database_url ⇒ Object (readonly)

Returns the value of attribute database_url.



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# File 'lib/taps/client_session.rb', line 12

def database_url
  @database_url
end

#default_chunksize ⇒ Object (readonly)

Returns the value of attribute default_chunksize.



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# File 'lib/taps/client_session.rb', line 12

def default_chunksize
  @default_chunksize
end

#remote_url ⇒ Object (readonly)

Returns the value of attribute remote_url.



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# File 'lib/taps/client_session.rb', line 12

def remote_url
  @remote_url
end

Class Method Details

.quickstart(&block) ⇒ Object 



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# File 'lib/taps/client_session.rb', line 26

def self.quickstart(&block)
	start(Taps::Config.database_url, Taps::Config.remote_url, Taps::Config.chunksize) do |s|
		yield s
	end
end

.start(database_url, remote_url, default_chunksize) {|s| ... } ⇒ Object

Yields:

  • (s) 


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# File 'lib/taps/client_session.rb', line 20

def self.start(database_url, remote_url, default_chunksize, &block)
	s = new(database_url, remote_url, default_chunksize)
	yield s
	s.close_session
end

Instance Method Details

#close_session ⇒ Object 



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# File 'lib/taps/client_session.rb', line 53

def close_session
	@session_resource.delete(http_headers) if @session_resource
end

#cmd_receive ⇒ Object 



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# File 'lib/taps/client_session.rb', line 173

def cmd_receive
	begin
		verify_server
		cmd_receive_schema
		cmd_receive_data
		cmd_receive_indexes
		cmd_reset_sequences
	rescue RestClient::Exception => e
		if e.respond_to?(:response)
			puts "!!! Caught Server Exception"
			puts "#{e.response.body}"
			exit(1)
		else
			raise
		end
	end
end

#cmd_receive_data ⇒ Object 



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# File 'lib/taps/client_session.rb', line 191

def cmd_receive_data
	puts "Receiving data"

	tables_with_counts, record_count = fetch_remote_tables_info

	puts "#{tables_with_counts.size} tables, #{format_number(record_count)} records"

	tables_with_counts.each do |table_name, count|
		table = db[table_name.to_sym]
		chunksize = default_chunksize

		progress = ProgressBar.new(table_name.to_s, count)

		offset = 0
		loop do
			begin
				chunksize, rows = fetch_table_rows(table_name, chunksize, offset)
			rescue CorruptedData
				next
			end
			break if rows == { }

			table.import(rows[:header], rows[:data])

			progress.inc(rows[:data].size)
			offset += rows[:data].size
		end

		progress.finish
	end
end

#cmd_receive_indexes ⇒ Object 



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# File 'lib/taps/client_session.rb', line 266

def cmd_receive_indexes
	puts "Receiving indexes"

	index_data = session_resource['indexes'].get(http_headers)

	output = Taps::Schema.load_indexes(database_url, index_data)
	puts output if output
end

#cmd_receive_schema ⇒ Object 



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# File 'lib/taps/client_session.rb', line 258

def cmd_receive_schema
	puts "Receiving schema"

	schema_data = session_resource['schema'].get(http_headers)
	output = Taps::Schema.load(database_url, schema_data)
	puts output if output
end

#cmd_reset_sequences ⇒ Object 



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# File 'lib/taps/client_session.rb', line 275

def cmd_reset_sequences
	puts "Resetting sequences"

	output = Taps::Schema.reset_db_sequences(database_url)
	puts output if output
end

#cmd_send ⇒ Object 



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# File 'lib/taps/client_session.rb', line 73

def cmd_send
	begin
		verify_server
		cmd_send_schema
		cmd_send_data
		cmd_send_indexes
		cmd_send_reset_sequences
	rescue RestClient::Exception => e
		if e.respond_to?(:response)
			puts "!!! Caught Server Exception"
			puts "#{e.response.body}"
			exit(1)
		else
			raise
		end
	end
end

#cmd_send_data ⇒ Object 



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# File 'lib/taps/client_session.rb', line 111

def cmd_send_data
	puts "Sending data"

	tables_with_counts, record_count = fetch_tables_info

	puts "#{tables_with_counts.size} tables, #{format_number(record_count)} records"


	db.tables.each do |table_name|
		table = db[table_name]
		count = table.count
		order = Taps::Utils.order_by(db, table_name)
		chunksize = self.default_chunksize
		string_columns = Taps::Utils.incorrect_blobs(db, table_name)

		progress = ProgressBar.new(table_name.to_s, count)

		offset = 0
		loop do
			row_size = 0
			chunksize = Taps::Utils.calculate_chunksize(chunksize) do |c|
				rows = Taps::Utils.format_data(table.order(*order).limit(c, offset).all, string_columns)
				break if rows == { }

				row_size = rows[:data].size
				gzip_data = Taps::Utils.gzip(Marshal.dump(rows))

				begin
					session_resource["tables/#{table_name}"].post(gzip_data, http_headers({
						:content_type => 'application/octet-stream',
						:taps_checksum => Taps::Utils.checksum(gzip_data).to_s}))
				rescue RestClient::RequestFailed => e
					# retry the same data, it got corrupted somehow.
					if e.http_code == 412
						next
					end
					raise
				end
			end

			progress.inc(row_size)
			offset += row_size

			break if row_size == 0
		end

		progress.finish
	end
end

#cmd_send_indexes ⇒ Object 



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# File 'lib/taps/client_session.rb', line 91

def cmd_send_indexes
	puts "Sending indexes"

	index_data = Taps::Schema.indexes(database_url)
	session_resource['indexes'].post(index_data, http_headers)
end

#cmd_send_reset_sequences ⇒ Object 



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# File 'lib/taps/client_session.rb', line 105

def cmd_send_reset_sequences
	puts "Resetting sequences"

	session_resource["reset_sequences"].post('', http_headers)
end

#cmd_send_schema ⇒ Object 



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# File 'lib/taps/client_session.rb', line 98

def cmd_send_schema
	puts "Sending schema"

	schema_data = Taps::Schema.dump_without_indexes(database_url)
	session_resource['schema'].post(schema_data, http_headers)
end

#db ⇒ Object 



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# File 'lib/taps/client_session.rb', line 32

def db
	@db ||= Sequel.connect(database_url)
end

#fetch_remote_tables_info ⇒ Object 



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# File 'lib/taps/client_session.rb', line 242

def fetch_remote_tables_info
	retries = 0
	max_retries = 1
	begin
		tables_with_counts = Marshal.load(session_resource['tables'].get(http_headers))
		record_count = tables_with_counts.values.inject(0) { |a,c| a += c }
	rescue RestClient::Exception
		retries += 1
		retry if retries <= max_retries
		puts "Unable to fetch tables information from #{remote_url}. Please check the server log."
		exit(1)
	end

	[ tables_with_counts, record_count ]
end

#fetch_table_rows(table_name, chunksize, offset) ⇒ Object

Raises:



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# File 'lib/taps/client_session.rb', line 225

def fetch_table_rows(table_name, chunksize, offset)
	response = nil
	chunksize = Taps::Utils.calculate_chunksize(chunksize) do |c|
		response = session_resource["tables/#{table_name}/#{c}?offset=#{offset}"].get(http_headers)
	end
	raise CorruptedData unless Taps::Utils.valid_data?(response.to_s, response.headers[:taps_checksum])

	begin
		rows = Marshal.load(Taps::Utils.gunzip(response.to_s))
	rescue Object => e
		puts "Error encountered loading data, wrote the data chunk to dump.#{Process.pid}.gz"
		File.open("dump.#{Process.pid}.gz", "w") { |f| f.write(response.to_s) }
		raise
	end
	[chunksize, rows]
end

#fetch_tables_info ⇒ Object 



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# File 'lib/taps/client_session.rb', line 161

def fetch_tables_info
	record_count = 0
	tables = db.tables
	tables_with_counts = tables.inject({}) do |accum, table|
		accum[table] = db[table].count
		record_count += accum[table]
		accum
	end

	[ tables_with_counts, record_count ]
end

#format_number(num) ⇒ Object 



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# File 'lib/taps/client_session.rb', line 282

def format_number(num)
	num.to_s.gsub(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1,")
end

#http_headers(extra = {}) ⇒ Object 



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# File 'lib/taps/client_session.rb', line 69

def http_headers(extra = {})
	{ :taps_version => Taps.compatible_version }.merge(extra)
end

#open_session ⇒ Object 



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# File 'lib/taps/client_session.rb', line 44

def open_session
	uri = server['sessions'].post('', http_headers)
	server[uri]
end

#safe_database_url ⇒ Object 



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# File 'lib/taps/client_session.rb', line 65

def safe_database_url
	safe_url(database_url)
end

#safe_remote_url ⇒ Object 



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# File 'lib/taps/client_session.rb', line 61

def safe_remote_url
	safe_url(remote_url)
end

#safe_url(url) ⇒ Object 



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# File 'lib/taps/client_session.rb', line 57

def safe_url(url)
	url.sub(/\/\/(.+?)?:(.*?)@/, '//\1:[hidden]@')
end

#server ⇒ Object 



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# File 'lib/taps/client_session.rb', line 36

def server
	@server ||= RestClient::Resource.new(remote_url)
end

#session_resource ⇒ Object 



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# File 'lib/taps/client_session.rb', line 40

def session_resource
	@session_resource ||= open_session
end

#set_session(uri) ⇒ Object 



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# File 'lib/taps/client_session.rb', line 49

def set_session(uri)
	@session_resource = server[uri]
end

#verify_server ⇒ Object 



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# File 'lib/taps/client_session.rb', line 286

def verify_server
	begin
		server['/'].get(http_headers)
	rescue RestClient::RequestFailed => e
		if e.http_code == 417
			puts "#{safe_remote_url} is running a different minor version of taps."
			puts "#{e.response.body}"
			exit(1)
		else
			raise
		end
	rescue RestClient::Unauthorized
		puts "Bad credentials given for #{safe_remote_url}"
		exit(1)
	rescue Errno::ECONNREFUSED
		puts "Can't connect to #{safe_remote_url}. Please check that it's running"
		exit(1)
	end
end