aerospike_helpers.cdt_ctx module

Note

Requires server version >= 4.6.0

Helper functions to generate complex data type context (cdt_ctx) objects for use with operations on nested CDTs (list, map, etc).

Example:

import aerospike
from aerospike import exception as ex
from aerospike_helpers import cdt_ctx
from aerospike_helpers.operations import map_operations
from aerospike_helpers.operations import list_operations
import sys

# Configure the client.
config = {"hosts": [("127.0.0.1", 3000)]}
client = aerospike.client(config)

key = ("test", "demo", "foo")
listWithMaps = [
    {"name": "John", "id": 100},
    {"name": "Bill", "id": 200}
]
binName = "users"

# Write the record
client.put(key, {binName: listWithMaps})

# Example 1: read the id of the second person on the list
# Get context of the second person
ctx = [cdt_ctx.cdt_ctx_list_index(1)]
ops = [
    map_operations.map_get_by_key(
        binName, "id", aerospike.MAP_RETURN_VALUE, ctx
    )
]

_, _, result = client.operate(key, ops)
print(result)
# {'users': 200}

# Example 2: add a new person and get their rating of Facebook
cindy = {
    "name": "Cindy",
    "id": 300,
    "ratings": {
        "Facebook": 4,
        "Snapchat": 5
    }
}

# Context list used for read operation after adding Cindy
# Cindy will be the third person (index 2)
# Then go to their ratings
ctx = [cdt_ctx.cdt_ctx_list_index(2), cdt_ctx.cdt_ctx_map_key("ratings")]
ops = [
    list_operations.list_append(binName, cindy),
    map_operations.map_get_by_key(
        binName, "Facebook", aerospike.MAP_RETURN_VALUE, ctx
    )
]

_, _, result = client.operate(key, ops)
print(result)
# {'users': 4}

# Example 3: create a CDT secondary index from a base64 encoded _cdt_ctx with info command
policy = {}

bs_b4_cdt = client.get_cdtctx_base64(ctx_list_index)

r = []
r.append("sindex-create:ns=test;set=demo;indexname=test_string_list_cdt_index")
# use index_type_string to convert enum value to string
r.append(";indextype=%s" % (cdt_ctx.index_type_string(aerospike.INDEX_TYPE_LIST)))
# use index_datatype_string to convert enum value to string
r.append(";indexdata=string_list,%s" % (cdt_ctx.index_datatype_string(aerospike.INDEX_STRING)))
r.append(";context=%s" % (bs_b4_cdt))
req = ''.join(r)

# print("req is ==========={}", req)
retobj = client.info_all(req, policy=None)
# print("res is ==========={}", res)
client.index_remove('test', 'test_string_list_cdt_index', policy)

# Cleanup
client.remove(key)
client.close()

Path Expressions Contexts

These _cdt_ctx methods are meant to be used with path expressions:

cdt_ctx_all_children()
cdt_ctx_all_children_with_filter()
cdt_ctx_map_keys_in()
cdt_ctx_and_filter()

aerospike_helpers.cdt_ctx.cdt_ctx_all_children() → _cdt_ctx

At the current context, causes a query to return a list of all the children of the current item. For a map, this will recurse into the map elements. For a list, this will include all the children in the list.

Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_all_children_with_filter(expression: TypeExpression) → _cdt_ctx

All children of the current level will be selected, and then the filter expression is applied to each item in turn. Items that cause the expression to evaluate to true will be added to the list of items returned in a query for this level. Items that cause the expression to evaluate to false will be filtered out.

Parameters:: expression – Compiled expression. This expression must return a boolean.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_and_filter(expression: TypeExpression) → _cdt_ctx

Add a boolean expression filter AND-combined with a previous cdt_ctx_map_keys_in().

This applies the expression at the same level as the previous path context.

Restrictions:

Only one cdt_ctx_and_filter() is allowed per context level. Multiple cdt_ctx_and_filter() calls cannot be chained. To combine multiple conditions, use And within a single cdt_ctx_and_filter().

The preceding context entry must not be an expression type (i.e. cdt_ctx_and_filter() cannot follow cdt_ctx_all_children_with_filter() or cdt_ctx_all_children()).

cdt_ctx_and_filter() cannot be the first entry in the context chain.

Parameters:: expression – Compiled expression. This expression must return a boolean.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_list_index(index)

Creates a nested cdt_ctx object to lookup an object in a list by index.

If the index is negative, the lookup starts backwards from the end of the list. If it is out of bounds, a parameter error will be returned.

Parameters:: index (int) – The index to look for in the list.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_list_index_create(index: int, order: int = 0, pad: bool = False) → _cdt_ctx

Creates a nested cdt_ctx object to create an list and insert at a given index.

If a list already exists at the index, a new list will not be created. Any operations using this cdt_ctx object will be applied to the existing list.

If a non-list element exists at the index, an InvalidRequest will be thrown.

Parameters:

index (int) – The index to create the list at.
order (int) – The sort order to create the List with. (default: aerospike.LIST_UNORDERED)
pad (bool) – If index is out of bounds and pad is True, then the list will be created at the index with None elements inserted behind it. pad is only compatible with unordered lists.

Returns:

_cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_list_rank(rank)

Creates a nested cdt_ctx object to lookup an object in a list by rank.

If the rank is negative, the lookup starts backwards from the largest rank value.

Parameters:: rank (int) – The rank to look for in the list.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_list_value(value)

Creates a nested cdt_ctx object to lookup an object in a list by value.

Parameters:: value (object) – The value to look for in the list.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_map_index(index)

The cdt_ctx object is initialized to lookup an object in a map by index.

If the index is negative, the lookup starts backwards from the end of the map.

If it is out of bounds, a parameter error will be returned.

Parameters:: index (int) – The index to look for in the map.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_map_key(key)

The cdt_ctx object is initialized to lookup an object in a map by key.

Parameters:: key (object) – The key to look for in the map.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_map_key_create(key: any, order: int = 0) → _cdt_ctx

Create a map with the given sort order at the given key.

Parameters:

key (object) – The key to create the map at.
order (int) – The sort order to create the List with. (default: aerospike.MAP_UNORDERED)

Returns:

_cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_map_keys_in(keys: list)

Restrict map context to the given list of keys, provided they exist.

For example, if a map {"A": 1, "B": 2, "C": 3} exists, and you pass keys ["A", "C", "D"] in as the list of keys, the result will only include {"A": 1, "C": 3}, since element “D” does not exist in the map.

This can be followed by cdt_ctx_and_filter() to filter out the remaining map entries.

This can only be used by path expressions.

Parameters:: keys (list) – The keys to look for in the map.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_map_rank(rank)

The cdt_ctx object is initialized to lookup an object in a map by index.

If the rank is negative, the lookup starts backwards from the largest rank value.

Parameters:: rank (int) – The rank to look for in the map.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.cdt_ctx_map_value(value)

The cdt_ctx object is initialized to lookup an object in a map by value.

Parameters:: value (object) – The value to look for in the map.
Returns:: _cdt_ctx

aerospike_helpers.cdt_ctx.index_datatype_string(index_datatype)

Converts index_datatype enum value to string.

Parameters:: index_datatype (int) – The index_datatype to convert into equivalent string value.
Returns:: (string) - must be one of must be one of ‘numeric’, ‘string’, ‘geo2dsphere’

aerospike_helpers.cdt_ctx.index_type_string(index_type)

Converts index_type enum value to string.

Parameters:: index_type (int) – The index_type to convert into equivalent string value.
Returns:: (string) - must be one of ‘default’, ‘list’, ‘mapkeys’, ‘mapvalues’