qbits.alia.component — cc.qbits/alia-component 4.3.7-beta1

Alia module bringing component and spec support. As a consumer, a CassandraRegistry record is provided.

CassandraRegistry instances are responsible for maintaining sessions to clusters.

Downstream consumers of this component can then provide a map of query functions and obtain a function which performs queries against the correct cluster and optional default query options.

See query-functions for details on how to use it.

->opts clj

(->opts nick config code-opts)

This should provide a solid way to parameterize interaction with Cassandra. For each named query nick we determine what options to give to the query in the following way:

• We fetch defaults from the configuration provided query options
• We merge code-local defaults for this query
• We merge query-specific defaults from configuration

->query clj

(->query nick session query-opts {:keys [statement opts]})

Get a function which executes a query, preparing the statement.

cassandra-registry clj

(cassandra-registry cluster-opts query-opts config)

A single cluster version of CassandraMultiClusterRegistry

cluster-query-opts clj

(cluster-query-opts registry cluster-name)

Fetch query-options from configuration.

keyspace-session clj

(keyspace-session registry k keyspace)

Retrieve a Session instance set to use a specific keyspace. keyspace may be a keyword or string.

query! clj

(query! {:keys [query-fn]} & args)

Convenience function against a QueryRegistry to execute a named query. See query-functions for the behavior of the query function

query-fn-map clj

(query-fn-map session queries query-opts)

Yield a map of query nickname to function executing the query. Provided queries should be statements valid for alia/prepare.

query-functions clj

(query-functions registry keyspace queries)

(query-functions registry cluster-name keyspace queries)

Given a cluster, keyspace, and query map, yield a function which executes queries by nickname. If no cluster-name is provided, assume a single-cluster registry and fetch the first from the registry.

The query function has three arities: 1, 2, and 3. The first argument is always the nickname, the optional second one is a vector of values to attach to the prepared query, the last one additional options to override when sending the query.

Here, options accept an addition :execute-fn key which determine which function should be used to send the query out, defaulting to alia/execute.

Each query can be configured with global configuration defaults, code-supplied defaults, and query-specific configuration overrides, processed in that order as documented in query.