class Qpid::Proton::Data
The Data
class provides an interface for decoding, extracting,
creating, and encoding arbitrary AMQP data. A Data
object
contains a tree of AMQP values. Leaf nodes in this tree correspond to
scalars in the AMQP type system such as INT or STRING. Interior nodes in this tree correspond to
compound values in the AMQP type system such as
LIST,MAP, ARRAY, or
DESCRIBED. The root node of the tree is the
Data
object itself and can have an arbitrary number of
children.
A Data
object maintains the notion of the current sibling node
and a current parent node. Siblings are ordered within their parent. Values
are accessed and/or added by using the next, prev, enter, and exit methods to navigate to the desired
location in the tree and using the supplied variety of mutator and accessor
methods to access or add a value of the desired type.
The mutator methods will always add a value after the current node in the tree. If the current node has a next sibling the mutator method will overwrite the value on this node. If there is no current node or the current node has no next sibling then one will be added. The accessor methods always set the added/modified node to the current node. The accessor methods read the value of the current node and do not change which node is current.
The following types of scalar values are supported:
-
NULL
-
BOOL
-
UBYTE
-
BYTE
-
USHORT
-
SHORT
-
UINT
-
INT
-
CHAR
-
ULONG
-
LONG
-
TIMESTAMP
-
FLOAT
-
DOUBLE
-
DECIMAL32
-
DECIMAL64
-
DECIMAL128
-
UUID
-
BINARY
-
STRING
-
SYMBOL
The following types of compound values are supported:
-
DESCRIBED
-
ARRAY
-
LIST
-
MAP
Public Class Methods
Creates a new instance with the specified capacity.
Options¶ ↑
-
capacity - the capacity
# File lib/qpid_proton/data.rb, line 93 def initialize(capacity = 16) if (!capacity.nil?) && (capacity.is_a?(Fixnum) || capacity.is_a?(Bignum)) @data = Cproton.pn_data(capacity) @free = true else @data = capacity @free = false end # destructor ObjectSpace.define_finalizer(self, self.class.finalize!(@data)) end
Public Instance Methods
If the current node is an array, returns a tuple of the element count, a boolean indicating whether the array is described, and the type of each element. Otherwise it returns +(0, false, nil).
Array data can be accessed by entering the array.
Examples¶ ↑
# get the details of thecurrent array count, described, array_type = @data.array # enter the node data.enter # get the next node data.next puts "Descriptor: #{data.symbol}" if described (0...count).each do @data.next puts "Element: #{@data.string}" end
# File lib/qpid_proton/data.rb, line 341 def array count = Cproton.pn_data_get_array(@data) described = Cproton.pn_data_is_array_described(@data) array_type = Cproton.pn_data_get_array_type(@data) return nil if array_type == -1 [count, described, Mapping.for_code(array_type) ] end
If the current node is binary, returns its value. Otherwise, it returns an empty string (“”).
# File lib/qpid_proton/data.rb, line 727 def binary Cproton.pn_data_get_binary(@data) end
If the current node is a boolean, then it returns the value. Otherwise, it returns false.
# File lib/qpid_proton/data.rb, line 426 def bool Cproton.pn_data_get_bool(@data) end
If the current node is an byte, returns its value. Otherwise, it returns 0.
# File lib/qpid_proton/data.rb, line 456 def byte Cproton.pn_data_get_byte(@data) end
If the current node is a character, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 533 def char Cproton.pn_data_get_char(@data) end
Clears the object.
# File lib/qpid_proton/data.rb, line 123 def clear Cproton.pn_data_clear(@data) end
If the current node is a decimal128, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 659 def decimal128 value = "" Cproton.pn_data_get_decimal128(@data).each{|val| value += ("%02x" % val)} value.to_i(16) end
Puts a decimal128 value.
Options¶ ↑
-
value - the decimal128 value
# File lib/qpid_proton/data.rb, line 649 def decimal128=(value) raise TypeError, "invalid decimal128 value: #{value}" if value.nil? value = value.to_s(16).rjust(32, "0") bytes = [] value.scan(/(..)/) {|v| bytes << v[0].to_i(16)} check(Cproton.pn_data_put_decimal128(@data, bytes)) end
If the current node is a decimal32, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 625 def decimal32 Cproton.pn_data_get_decimal32(@data) end
If the current node is a decimal64, returns its value. Otherwise, it returns 0.
# File lib/qpid_proton/data.rb, line 640 def decimal64 Cproton.pn_data_get_decimal64(@data) end
Checks if the current node is a described value.
The described and value may be accessed by entering the described value.
Examples¶ ↑
if @data.described? @data.enter puts "The symbol is #{@data.symbol}" puts "The value is #{@data.string}" end
# File lib/qpid_proton/data.rb, line 396 def described? Cproton.pn_data_is_described(@data) end
If the current node is a double, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 610 def double Cproton.pn_data_get_double(@data) end
Returns a representation of the data encoded in AMQP format.
# File lib/qpid_proton/data.rb, line 176 def encode buffer = "\0"*1024 loop do cd = Cproton.pn_data_encode(@data, buffer, buffer.length) if cd == Cproton::PN_OVERFLOW buffer *= 2 elsif cd >= 0 return buffer[0...cd] else check(cd) end end end
Sets the parent node to the current node and clears the current node.
Clearing the current node sets it before the first child.
# File lib/qpid_proton/data.rb, line 154 def enter Cproton.pn_data_enter(@data) end
Sets the current node to the parent node and the parent node to its own parent.
# File lib/qpid_proton/data.rb, line 160 def exit Cproton.pn_data_exit(@data) end
If the current node is a float, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 595 def float Cproton.pn_data_get_float(@data) end
Get the current value as a single object.
# File lib/qpid_proton/data.rb, line 764 def get type.get(self); end
If the current node is an integer, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 518 def int Cproton.pn_data_get_int(@data) end
If the current node is a list, this returns the number of elements. Otherwise, it returns zero.
List elements can be accessed by entering the list.
Examples¶ ↑
count = @data.list @data.enter (0...count).each type = @data.next puts "Value: #{@data.string}" if type == STRING # ... process other node types end
# File lib/qpid_proton/data.rb, line 234 def list Cproton.pn_data_get_list(@data) end
If the current node is a long, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 564 def long Cproton.pn_data_get_long(@data) end
If the current node is a map, this returns the number of child elements. Otherwise, it returns zero.
Key/value pairs can be accessed by entering the map.
Examples¶ ↑
count = @data.map @data.enter (0...count).each do type = @data.next puts "Key=#{@data.string}" if type == STRING # ... process other key types type = @data.next puts "Value=#{@data.string}" if type == STRING # ... process other value types end @data.exit
# File lib/qpid_proton/data.rb, line 274 def map Cproton.pn_data_get_map(@data) end
Advances the current node to its next sibling and returns its types.
If there is no next sibling the current node remains unchanged and nil is returned.
# File lib/qpid_proton/data.rb, line 139 def next(print = false) Cproton.pn_data_next(@data) end
Puts a null value.
# File lib/qpid_proton/data.rb, line 401 def null check(Cproton.pn_data_put_null(@data)) end
Checks if the current node is null.
# File lib/qpid_proton/data.rb, line 411 def null? Cproton.pn_data_is_null(@data) end
Advances the current node to its previous sibling and returns its type.
If there is no previous sibling then the current node remains unchanged and nil is return.
# File lib/qpid_proton/data.rb, line 147 def prev return Cproton.pn_data_prev(@data) ? type : nil end
Put value as an object of type type_
# File lib/qpid_proton/data.rb, line 769 def put(value, type_); type_.put(self, value); end
Puts an array value.
Elements may be filled by entering the array node and putting the element values. The values must all be of the specified array element type.
If an array is described then the first child value of the array is the descriptor and may be of any type.
Options¶ ↑
-
described - specifies whether the array is described
-
element_type - the type of the array elements
Examples¶ ↑
# create an array of integer values data = Qpid::Proton::Data.new data.put_array(false, INT) data.enter data.int = 1 data.int = 2 data.int = 3 data.exit # create an array of double values data.put_array(true, DOUBLE) data.enter data.symbol = "array-descriptor" data.double = 1.1 data.double = 1.2 data.double = 1.3 data.exit
# File lib/qpid_proton/data.rb, line 316 def put_array(described, element_type) check(Cproton.pn_data_put_array(@data, described, element_type.code)) end
Puts a described value.
A described node has two children, the descriptor and the value. These are specified by entering the node and putting the desired values.
Examples¶ ↑
data = Qpid::Proton::Data.new data.put_described data.enter data.symbol = "value-descriptor" data.string = "the value" data.exit
# File lib/qpid_proton/data.rb, line 368 def put_described check(Cproton.pn_data_put_described(@data)) end
Puts a list value.
Elements may be filled by entering the list node and putting element values.
Examples¶ ↑
data = Qpid::Proton::Data.new data.put_list data.enter data.int = 1 data.int = 2 data.int = 3 data.exit
# File lib/qpid_proton/data.rb, line 216 def put_list check(Cproton.pn_data_put_list(@data)) end
Puts a map value.
Elements may be filled by entering the map node and putting alternating key/value pairs.
Examples¶ ↑
data = Qpid::Proton::Data.new data.put_map data.enter data.string = "key" data.string = "value" data.exit
# File lib/qpid_proton/data.rb, line 252 def put_map check(Cproton.pn_data_put_map(@data)) end
Clears the current node and sets the parent to the root node.
Clearing the current node sets it before the first node, calling next will advance to the first node.
# File lib/qpid_proton/data.rb, line 131 def rewind Cproton.pn_data_rewind(@data) end
If the current node is a short, returns its value. Otherwise, returns a 0.
# File lib/qpid_proton/data.rb, line 486 def short Cproton.pn_data_get_short(@data) end
If the current node is a string, returns its value. Otherwise, it returns an empty string (“”).
# File lib/qpid_proton/data.rb, line 744 def string Cproton.pn_data_get_string(@data) end
If the current node is a symbol, returns its value. Otherwise, it returns an empty string (“”).
# File lib/qpid_proton/data.rb, line 759 def symbol Cproton.pn_data_get_symbol(@data) end
If the current node is a timestamp, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 580 def timestamp Cproton.pn_data_get_timestamp(@data) end
# File lib/qpid_proton/data.rb, line 114 def to_s tmp = Cproton.pn_string("") Cproton.pn_inspect(@data, tmp) result = Cproton.pn_string_get(tmp) Cproton.pn_free(tmp) return result end
Return the Type object for the current node
# File lib/qpid_proton/data.rb, line 171 def type Mapping.for_code(type_code) end
Returns the numeric type code of the current node.
# File lib/qpid_proton/data.rb, line 165 def type_code dtype = Cproton.pn_data_type(@data) return (dtype == -1) ? nil : dtype end
If the current node is an unsigned byte, returns its value. Otherwise, it reutrns 0.
# File lib/qpid_proton/data.rb, line 441 def ubyte Cproton.pn_data_get_ubyte(@data) end
If the current node is an unsigned int, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 503 def uint Cproton.pn_data_get_uint(@data) end
If the current node is an unsigned long, returns its value. Otherwise, returns 0.
# File lib/qpid_proton/data.rb, line 550 def ulong Cproton.pn_data_get_ulong(@data) end
If the current node is an unsigned short, returns its value. Otherwise, it returns 0.
# File lib/qpid_proton/data.rb, line 471 def ushort Cproton.pn_data_get_ushort(@data) end
If the current value is a UUID
, returns its value. Otherwise,
it returns nil.
# File lib/qpid_proton/data.rb, line 710 def uuid value = "" Cproton.pn_data_get_uuid(@data).each{|val| value += ("%02x" % val)} value.insert(8, "-").insert(13, "-").insert(18, "-").insert(23, "-") end
Puts a UUID
value.
The UUID is expected to be in the format of a string or else a 128-bit integer value.
Options¶ ↑
-
value - the
UUID
Examples¶ ↑
# set a uuid value from a string value require 'securerandom' @data.uuid = SecureRandom.uuid # or @data.uuid = "fd0289a5-8eec-4a08-9283-81d02c9d2fff" # set a uuid value from a 128-bit value @data.uuid = 0 # sets to 00000000-0000-0000-0000-000000000000
# File lib/qpid_proton/data.rb, line 686 def uuid=(value) raise ArgumentError, "invalid uuid: #{value}" if value.nil? # if the uuid that was submitted was numeric value, then translated # it into a hex string, otherwise assume it was a string represtation # and attempt to decode it if value.is_a? Numeric value = "%032x" % value else raise ArgumentError, "invalid uuid: #{value}" if !valid_uuid?(value) value = (value[0, 8] + value[9, 4] + value[14, 4] + value[19, 4] + value[24, 12]) end bytes = [] value.scan(/(..)/) {|v| bytes << v[0].to_i(16)} check(Cproton.pn_data_put_uuid(@data, bytes)) end
Private Instance Methods
# File lib/qpid_proton/data.rb, line 775 def valid_uuid?(value) # ensure that the UUID is in the right format # xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx value =~ /[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}/ end