Provides a sequential identification scheme for Neo4j nodes.

Introduced classes

class SequentialNodeCollection

neo4j :: SequentialNodeCollection

A Neo4j node collection using a sequential identification scheme.

All class definitions

class SequentialNodeCollection

neo4j $ SequentialNodeCollection

A Neo4j node collection using a sequential identification scheme.
package_diagram neo4j::sequential_id sequential_id neo4j\>graph\> graph neo4j::sequential_id->neo4j\>graph\> pipeline pipeline neo4j::sequential_id->pipeline neo4j\>graph\>->pipeline neo4j neo4j neo4j\>graph\>->neo4j progression progression neo4j\>graph\>->progression ...neo4j ... ...neo4j->neo4j ...progression ... ...progression->progression ...pipeline ... ...pipeline->pipeline a_star-m a_star-m a_star-m->neo4j::sequential_id


module abstract_collection

core :: abstract_collection

Abstract collection classes and services.
module abstract_text

core :: abstract_text

Abstract class for manipulation of sequences of characters
module array

core :: array

This module introduces the standard array structure.
module bitset

core :: bitset

Services to handle BitSet
module bytes

core :: bytes

Services for byte streams and arrays
module caching

serialization :: caching

Services for caching serialization engines
module circular_array

core :: circular_array

Efficient data structure to access both end of the sequence.
module codec_base

core :: codec_base

Base for codecs to use with streams
module codecs

core :: codecs

Group module for all codec-related manipulations
module collection

core :: collection

This module define several collection classes.
module core

core :: core

Standard classes and methods used by default by Nit programs and libraries.
module curl

curl :: curl

Data transfer powered by the native curl library
module curl_json

neo4j :: curl_json

cURL requests compatible with the JSON REST APIs.
module engine_tools

serialization :: engine_tools

Advanced services for serialization engines
module environ

core :: environ

Access to the environment variables of the process
module error

json :: error

Intro JsonParseError which is exposed by all JSON reading APIs
module error

neo4j :: error

Errors thrown by the neo4j library.
module error

core :: error

Standard error-management infrastructure.
module exec

core :: exec

Invocation and management of operating system sub-processes.
module file

core :: file

File manipulations (create, read, write, etc.)
module fixed_ints

core :: fixed_ints

Basic integers of fixed-precision
module fixed_ints_text

core :: fixed_ints_text

Text services to complement fixed_ints
module flat

core :: flat

All the array-based text representations
module gc

core :: gc

Access to the Nit internal garbage collection mechanism
module hash_collection

core :: hash_collection

Introduce HashMap and HashSet.
module inspect

serialization :: inspect

Refine Serializable::inspect to show more useful information
module iso8859_1

core :: iso8859_1

Codec for ISO8859-1 I/O
module json

json :: json

Read and write JSON formatted text using the standard serialization services
module kernel

core :: kernel

Most basic classes and methods.
module list

core :: list

This module handle double linked lists
module math

core :: math

Mathematical operations
module meta

meta :: meta

Simple user-defined meta-level to manipulate types of instances as object.
module native

core :: native

Native structures for text and bytes
module native_curl

curl :: native_curl

Binding of C libCurl which allow us to interact with network.
module neo4j

neo4j :: neo4j

Neo4j connector through its JSON REST API using curl.
module numeric

core :: numeric

Advanced services for Numeric types
module parser_base

parser_base :: parser_base

Simple base for hand-made parsers of all kinds
module poset

poset :: poset

Pre order sets and partial order set (ie hierarchies)
module progression

progression :: progression

Event-based interface to track the progression of an operation.
module protocol

core :: protocol

module queue

core :: queue

Queuing data structures and wrappers
module range

core :: range

Module for range of discrete objects.
module re

core :: re

Regular expression support for all services based on Pattern
module ropes

core :: ropes

Tree-based representation of a String.
module safe

serialization :: safe

Services for safer deserialization engines
module serialization

serialization :: serialization

General serialization services
module serialization_core

serialization :: serialization_core

Abstract services to serialize Nit objects to different formats
module serialization_read

json :: serialization_read

Services to read JSON: deserialize_json and JsonDeserializer
module serialization_write

json :: serialization_write

Services to write Nit objects to JSON strings: serialize_to_json and JsonSerializer
module sorter

core :: sorter

This module contains classes used to compare things and sorts arrays.
module static

json :: static

Static interface to read Nit objects from JSON strings
module stream

core :: stream

Input and output streams of characters
module text

core :: text

All the classes and methods related to the manipulation of text entities
module time

core :: time

Management of time and dates
module union_find

core :: union_find

union–find algorithm using an efficient disjoint-set data structure
module utf8

core :: utf8

Codec for UTF-8 I/O


module graph

neo4j :: graph

Provides an interface for services on a Neo4j graphs.
module pipeline

pipeline :: pipeline

Pipelined filters and operations on iterators.


module a_star-m


# Provides a sequential identification scheme for Neo4j nodes.
module neo4j::graph::sequential_id

import graph
private import pipeline

# A Neo4j node collection using a sequential identification scheme.
# The local IDs are sequential numbers (integers) starting at `1`.
# Note: When loading nodes, the local IDs should forms a mostly contiguous
# range starting at `1`. Else, this collection will consume a lot of memory.
# Futhermore, the local IDs **must** be positive.
# ~~~nit
# var nodes = new SequentialNodeCollection("id")
# var a = nodes.create_node
# var b = new NeoNode
# var c = new NeoNode
# nodes.register b
# c["id"] = 4
# nodes.add c
# assert a["id"] == 1
# assert b["id"] == 2
# assert c["id"] == 4
# assert nodes.to_a == [a, b, c]
# assert nodes.length == 3
# nodes.compact
# assert a["id"] == 1
# assert b["id"] == 2
# assert c["id"] == 3
# assert nodes.to_a == [a, b, c]
# assert nodes.length == 3
# ~~~
class SequentialNodeCollection
	super NeoNodeCollection

	redef type ID_TYPE: Int

	private var nodes = new Array[nullable NeoNode]

	redef var length = 0

	redef fun iterator do return new NullSkipper[NeoNode](self.nodes.iterator)

	redef fun [](id) do return nodes[id].as(NeoNode)

	redef fun get_or_null(id) do
		if id < 0 or id > nodes.length then return null
		return nodes[id]

	redef fun has_id(id) do
		return id >= 0 and id < nodes.length and nodes[id] isa NeoNode

	redef fun enlarge(cap) do nodes.enlarge(cap)

	redef fun register(node) do
		nodes.add node
		id_of(node) = nodes.length
		length += 1

	redef fun add(node) do
		var id = node[id_property]
		assert id isa Int else
			sys.stderr.write "The local ID must be an `Int`.\n"
		assert id >= 0 else
			sys.stderr.write "The local ID must be greater or equal to 0. Got {id}.\n"
		# Pad with nulls.
		var delta = id - nodes.length
		while delta > 0 do
			nodes.add null
			delta -= 1
		nodes[id] = node
		length += 1

	redef fun remove_at(id) do
		nodes[id] = null
		length -= 1

	redef fun clear do
		length = 0

	redef fun compact do
		var i = iterator

		nodes = new Array[nullable NeoNode]
		for n in i do
			nodes.add n
			id_of(n) = nodes.length