attributeStorageInfo.cmn.md

attributeStorageInfo

The attributeStorageInfo object describes the structure of the binary attribute data resource of a node. The following examples show how different attribute types are represented as a binary buffer.

Examples of attribute resources

String

Field	Type	Description
String count	UINT32	Number of strings in the buffer.
Total number of bytes	UINT32	Total number of bytes for all the stings, including NULL terminating character.
String size	UINT32[n]	Size of each string in bytes.
String data	byte[m]	String values. All strings are UTF8 encoded and NULL terminated.

A string object contains the following: { "Bratislava", "Berlin", "Wien", <empty>, "" }

5	24	11	7	5	0	1	Bratislava\0	Berlin\0	Wien\0		\0

Double

Field	Type	Description
Count	UINT32	Number of values in the buffer.
Padding*	bytes[4]	Padding to preserve 8 byte alignement for double values.
value	Double [count]	Double values.

Representing double values 2.5, 44.67,0.5 .

3	-	2.5	44.67	0.5

Short Integer

Field	Type	Description
Count	UINT32	Number of values in the buffer.
value	UINT16 [count]	16 bit integer values.

Integer values of 3,10,7.

3	3	10	7

Related:

cmn::3DSceneLayer, psl::3DSceneLayer

Properties

Property	Type	Description
key	string	The unique field identifier key.
name	string	The name of the field.
header	headerValue[]	Declares the headers of the binary attribute data.
ordering	string[]	Possible values for each array string: attributeByteCounts: Should only be present when working with string data types. attributeValues: Should always be present. ObjectIds
attributeValues	value	Represents the description for value encoding. For example: scalar or vector encoding.
attributeByteCounts	value	For string types only. Represents the byte count of the string, including the null character.
objectIds	value	Stores the object-id values of each feature within the node.

Note: properties in bold are required

Examples

Example: attributeStorageInfo for 3d object scene layer

 {
  "key": "f_2",
  "name": "Family",
  "header": [
    {
      "property": "count",
      "valueType": "UInt32"
    },
    {
      "property": "attributeValuesByteCount",
      "valueType": "UInt32"
    }
  ],
  "ordering": [
    "attributeByteCounts",
    "attributeValues"
  ],
  "attributeByteCounts": {
    "valueType": "UInt32",
    "valuesPerElement": 1
  },
  "attributeValues": {
    "valueType": "String",
    "encoding": "UTF-8",
    "valuesPerElement": 1
  }
}