Class: PostgresPR::Message
- Inherits:
-
Object
- Object
- PostgresPR::Message
show all
- Defined in:
- lib/postgres-pr/message.rb
Overview
Base class representing a PostgreSQL protocol message
Direct Known Subclasses
Authentification, BackendKeyData, CommandComplete, CopyInResponse, CopyOutResponse, DataRow, EmptyQueryResponse, ErrorResponse, NoticeResponse, ParameterStatus, Parse, ParseComplete, PasswordMessage, Query, ReadyForQuery, RowDescription, SSLRequest, StartupMessage, Terminate, UnknownMessageType
Constant Summary
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- MsgTypeMap =
One character message-typecode to class map
Hash.new { UnknownMessageType }
Class Method Summary
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Instance Method Summary
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Class Method Details
.create(buffer) ⇒ Object
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# File 'lib/postgres-pr/message.rb', line 61
def self.create(buffer)
obj = allocate
obj.parse(buffer)
obj
end
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.dump(*args) ⇒ Object
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# File 'lib/postgres-pr/message.rb', line 67
def self.dump(*args)
new(*args).dump
end
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.fields(*attribs) ⇒ Object
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# File 'lib/postgres-pr/message.rb', line 86
def self.fields(*attribs)
names = attribs.map {|name, type| name.to_s}
arg_list = names.join(", ")
ivar_list = names.map {|name| "@" + name }.join(", ")
sym_list = names.map {|name| ":" + name }.join(", ")
class_eval %[
attr_accessor #{ sym_list }
def initialize(#{ arg_list })
#{ ivar_list } = #{ arg_list }
end
]
end
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.read(stream, startup = false) ⇒ Object
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# File 'lib/postgres-pr/message.rb', line 46
def self.read(stream, startup=false)
type = stream.read_exactly_n_bytes(1) unless startup
length = stream.read_exactly_n_bytes(4).unpack('N').first
raise ParseError unless length >= 4
buffer = Buffer.of_size(startup ? length : 1+length)
buffer.write(type) unless startup
buffer.write_int32_network(length)
buffer.copy_from_stream(stream, length-4)
(startup ? StartupMessage : MsgTypeMap[type]).create(buffer)
end
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.register_message_type(type) ⇒ Object
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# File 'lib/postgres-pr/message.rb', line 37
def self.register_message_type(type)
raise "duplicate message type registration" if MsgTypeMap.has_key?(type)
MsgTypeMap[type] = self
self.const_set(:MsgType, type)
class_eval "def message_type; MsgType end"
end
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Instance Method Details
#dump(body_size = 0) {|buffer| ... } ⇒ Object
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# File 'lib/postgres-pr/message.rb', line 71
def dump(body_size=0)
buffer = Buffer.of_size(5 + body_size)
buffer.write(self.message_type)
buffer.write_int32_network(4 + body_size)
yield buffer if block_given?
raise DumpError unless buffer.at_end?
return buffer.content
end
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#parse(buffer) {|buffer| ... } ⇒ Object
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# File 'lib/postgres-pr/message.rb', line 80
def parse(buffer)
buffer.position = 5
yield buffer if block_given?
raise ParseError, buffer.inspect unless buffer.at_end?
end
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