toucan2.pipeline — io.github.camsaul/toucan2 1.0.0-beta2-SNAPSHOT

This is a low-level namespace implementing our query execution pipeline. Most of the stuff you'd use on a regular basis are implemented on top of stuff here.

*call-count-thunk* clj

Thunk function to call every time a query is executed if toucan2.execute/with-call-count is in use. Implementees of transduce-compiled-query-with-connection should invoke this every time a query gets executed. You can use increment-call-count! to simplify the chore of making sure it's non-nil before invoking it.

base-query-type clj

(base-query-type query-type)

E.g. something like :toucan.query-type/insert.*. The immediate descendant of :toucan.query-type/*.

(base-query-type :toucan.query-type/insert.instances)
=>
:toucan.query-type/insert.*

build clj

(build query-type model parsed-args resolved-query)

Helper for getting a built query for a resolved-query.

default-rf clj

(default-rf query-type)

do-traced-pipeline clj

(do-traced-pipeline thunk)

first-result-rf clj

(first-result-rf rf)

increment-call-count! clj

(increment-call-count!)

parent-query-type clj

(parent-query-type query-type)

query-type? clj

(query-type? query-type)

True if query-type derives from one of the various abstract query keywords such as :toucan.result-type/* or :toucan.query-type/*. This does not guarantee that the query type is a 'concrete', just that it is something with some sort of query type information.

reducible-built-query clj

(reducible-built-query query-type model built-query)

reducible-compiled-query clj

(reducible-compiled-query query-type model compiled-query)

reducible-compiled-query-with-connection clj

(reducible-compiled-query-with-connection conn query-type model compiled-query)

reducible-parsed-args clj

(reducible-parsed-args query-type parsed-args)

reducible-resolved-query clj

(reducible-resolved-query query-type model parsed-args resolved-query)

reducible-unparsed clj

(reducible-unparsed query-type unparsed)

reducible-with-model clj

(reducible-with-model query-type model parsed-args)

resolve-query clj

(resolve-query query-type model unresolved-query)

Helper for getting the resolved query for unresolved-query.

similar-query-type-returning clj

(similar-query-type-returning query-type result-type)

(similar-query-type-returning :toucan.query-type/insert.instances :toucan.result-type/pks)
=>
:toucan.query-type/insert.pks

transduce-built-query clj

(transduce-built-query rf query-type₁ model₂ built-query₃)

The sixth step in the query execution pipeline. Called with a query that is ready to be compiled, e.g. a fully-formed Honey SQL form.

transduce-resolved-query
↓
(build query)
↓
transduce-built-query ← YOU ARE HERE
↓
toucan2.compile/with-compiled-query
↓
transduce-compiled-query

The default implementation compiles the query with toucan2.compile/with-compiled-query and then calls transduce-compiled-query.

transduce-compiled-query clj

(transduce-compiled-query rf query-type₁ model₂ compiled-query₃)

The seventh step in the query execution pipeline. Called with a compiled query that is ready to be executed natively, for example a [sql & args] vector, immediately before opening a connection.

transduce-built-query
↓
toucan2.compile/with-compiled-query
↓
transduce-compiled-query ← YOU ARE HERE
↓
toucan2.connection/with-connection
↓
transduce-compiled-query-with-connection

The default implementation opens a connection (or uses the current connection) using toucan2.connection/with-connection and then calls transduce-compiled-query-with-connection.

transduce-compiled-query-with-connection clj

(transduce-compiled-query-with-connection rf
                                          conn₁
                                          query-type₂
                                          model₃
                                          compiled-query)

The eighth and final step in the query execution pipeline. Called with a fully compiled query that can be executed natively, and an open connection for executing it.

transduce-compiled-query
↓
toucan2.connection/with-connection
↓
transduce-compiled-query-with-connection ← YOU ARE HERE
↓
execute query
↓
transduce results

Implementations should execute the query and transduce the results using rf. Implementations are database-specific, which is why this method dispatches off of connection type (e.g. java.sql.Connection). The default JDBC backend executes the query and reduces results with toucan2.jdbc.query/reduce-jdbc-query.

transduce-parsed-args clj

(transduce-parsed-args rf query-type₁ parsed-args)

The second step in the query execution pipeline. Called with args as parsed by something like toucan2.query/parse-args.

transduce-unparsed
↓
(parse args)
↓
transduce-parsed-args ← YOU ARE HERE
↓
toucan2.model/with-model
↓
transduce-with-model

The default implementation resolves the :modelable in parsed-args with toucan2.model/with-model and then calls transduce-with-model.

transduce-resolved-query clj

(transduce-resolved-query rf query-type₁ model₂ parsed-args resolved-query₃)

The fifth step in the query execution pipeline. Called with a resolved query immediately before 'building' it.

transduce-unresolved-query
↓
(resolve query)
↓
transduce-resolved-query ← YOU ARE HERE
↓
(build query)
↓
transduce-built-query

The default implementation builds the resolved query and then calls transduce-built-query.

transduce-unparsed clj

(transduce-unparsed rf query-type₁ unparsed-args)

The first step in the query execution pipeline. Called with the unparsed args as passed to something like toucan2.select/select, before parsing the args.

Entrypoint e.g. select/select
↓
transduce-unparsed           ← YOU ARE HERE
↓
(parse args)
↓
transduce-parsed-args

The default implementation parses the args with toucan2.query/parse-args and then calls transduce-parsed-args.

transduce-unparsed-first-result clj

(transduce-unparsed-first-result query-type unparsed)

transduce-unparsed-with-default-rf clj

(transduce-unparsed-with-default-rf query-type unparsed)

transduce-unresolved-query clj

(transduce-unresolved-query rf query-type₁ model₂ parsed-args unresolved-query₃)

The fourth step in the query execution pipeline.

transduce-with-model
↓
transduce-unresolved-query ← YOU ARE HERE
↓
(resolve query)
↓
transduce-resolved-query

The default implementation does nothing special with unresolved-query, and passes it directly to transduce-resolved-query.

transduce-with-model clj

(transduce-with-model rf query-type₁ model₂ parsed-args)

The third step in the query execution pipeline. This is the first step that dispatches off of resolved model.

transduce-parsed-args
↓
toucan2.model/with-model
↓
transduce-with-model ← YOU ARE HERE
↓
transduce-unresolved-query

The default implementation does nothing special and calls transduce-unresolved-query with the :queryable in parsed-args.

with-init clj

(with-init rf init)

Returns a version of reducing function rf with a zero-arity (initial value arity) that returns init.