Clojure
The xtdb.api
namespace exposes a union of methods from IXtdb
and IXtdbDatasource
,
with few lifecycle members added.
IXtdb
db
(db
[node]
[node db-basis]
^:deprecated [node valid-time]
^:deprecated [node valid-time tx-time]
"Returns a DB snapshot at the given time. The snapshot is not thread-safe.
db-basis: (optional map, all keys optional)
- `::xt/valid-time` (Date):
If provided, DB won't return any data with a valid-time greater than the given time.
Defaults to now.
- `::xt/tx` (Map):
If provided, DB will be a snapshot as of the given transaction.
Defaults to the latest completed transaction.
- `::xt/tx-time` (Date):
Shorthand for `{::xt/tx {::xt/tx-time <>}}`
Providing both `::xt/tx` and `::xt/tx-time` is undefined.
Arities passing dates directly (`node vt` and `node vt tt`) are deprecated and will be removed in a later release.
If the node hasn't yet indexed a transaction at or past the given transaction, this throws NodeOutOfSyncException")
open-db
(open-db
[node]
[node db-basis]
^:deprecated [node valid-time]
^:deprecated [node valid-time tx-time]
"Opens a DB snapshot at the given time.
db-basis: (optional map, all keys optional)
- `::xt/valid-time` (Date):
If provided, DB won't return any data with a valid-time greater than the given time.
Defaults to now.
- `::xt/tx` (Map):
If provided, DB will be a snapshot as of the given transaction.
Defaults to the latest completed transaction.
- `::xt/tx-time` (Date):
Shorthand for `{::xt/tx {::xt/tx-time <>}}`
Providing both `::xt/tx` and `::xt/tx-time` is undefined.
Arities passing dates directly (`node vt` and `node vt tt`) are deprecated and will be removed in a later release.
If the node hasn't yet indexed a transaction at or past the given transaction, this throws NodeOutOfSyncException
This DB opens up shared resources to make multiple requests faster - it must be `.close`d when you've finished
using it (for example, in a `with-open` block). Be cautious with lazy evaluation that may attempt to make requests
after the DB is closed.")
submit-tx
(submit-tx [node tx-ops]
"Writes transactions to the log for processing
tx-ops datalog style transactions.
Returns a map with details about the submitted transaction,
including tx-time and tx-id.")
tx-committed?
(tx-committed? [node submitted-tx]
"Checks if a submitted tx was successfully committed.
submitted-tx must be a map returned from `submit-tx`.
Returns true if the submitted transaction was committed,
false if the transaction was not committed, and throws `NodeOutOfSyncException`
if the node has not yet indexed the transaction.")
await-tx
(await-tx
[node tx]
[node tx ^Duration timeout]
"Blocks until the node has indexed a transaction that is at or past the
supplied tx. Will throw on timeout. Returns the most recent tx indexed by the
node.")
await-tx-time
(await-tx-time
[node ^Date tx-time]
[node ^Date tx-time ^Duration timeout]
"Blocks until the node has indexed a transaction that is past the supplied
txTime. Will throw on timeout. The returned date is the latest index time when
this node has caught up as of this call.")
sync
(sync
[node]
[node ^Duration timeout]
"Blocks until the node has caught up indexing to the latest tx available at
the time this method is called. Will throw an exception on timeout. The
returned date is the latest transaction time indexed by this node. This can be
used as the second parameter in (db valid-time, transaction-time) for
consistent reads.
timeout – max time to wait, can be nil for the default.
Returns the latest known transaction time.")
listen
(listen ^java.lang.AutoCloseable [node event-opts f]
"Attaches a listener to XTDB's event bus.
`event-opts` should contain `::xt/event-type`, along with any other options the event-type requires.
We currently only support one public event-type: `::xt/indexed-tx`.
Supplying `:with-tx-ops? true` will include the transaction's operations in the event passed to `f`.
`(.close ...)` the return value to detach the listener.
This is an experimental API, subject to change.")
open-tx-log
(open-tx-log ^ICursor [this after-tx-id with-ops?]
"Reads the transaction log. Optionally includes
operations, which allow the contents under the ::xt/tx-ops
key to be piped into (submit-tx tx-ops) of another
XTDB instance.
after-tx-id optional transaction id to start after.
with-ops? should the operations with documents be included?
Returns a cursor over the TxLog.")
latest-completed-tx
(latest-completed-tx [node]
"Returns the latest transaction to have been indexed by this node.")
IXtdbDatasource
Represents the database as of a specific valid and transaction time.
entity
(entity [db eid]
"queries a document map for an entity.
eid is an object which can be coerced into an entity id.
returns the entity document map.")
entity-tx
(entity-tx [db eid]
"returns the transaction details for an entity. Details
include tx-id and tx-time.
eid is an object that can be coerced into an entity id.")
q
(q
[db query]
"q[uery] an XTDB db.
This function will return a set of result tuples if you do not specify `:order-by`, `:limit` or `:offset`;
otherwise, it will return a vector of result tuples.)
open-q
(open-q
[db query]
"lazily q[uery] an XTDB db.
query param is a datalog query in map, vector or string form.
This function returns a Cursor of result tuples - once you've consumed
as much of the sequence as you need to, you'll need to `.close` the sequence.
A common way to do this is using `with-open`:
(with-open [res (xt/open-q db '{:find [...]
:where [...]})]
(doseq [row (iterator-seq res)]
...))
Once the sequence is closed, attempting to consume it is undefined (e.g.
may cause a JVM segfault crash when using RocksDB). Therefore, be
cautious with lazy evaluation.")
pull
(pull [db query eid]
"Returns the requested data for the given entity ID, based on the projection spec
e.g. `(pull db [:film/name :film/year] :spectre)`
=> `{:film/name \"Spectre\", :film/year 2015}`
See https://xtdb.com/reference/queries.html#pull for details of the spec format.")
pull-many
(pull-many [db query eids]
"Returns the requested data for the given entity IDs, based on the projection spec
e.g. `(pull-many db [:film/name :film/year] #{:spectre :skyfall})`
=> `[{:film/name \"Spectre\", :film/year 2015}, {:film/name \"Skyfall\", :film/year 2012}]`
See https://xtdb.com/reference/queries.html#pull for details of the spec format.")
entity-history
(entity-history
[db eid sort-order]
[db eid sort-order {:keys [with-docs?
with-corrections?
start-valid-time
end-valid-time
start-tx-time
end-tx-time
start-tx-id
end-tx-id]}]
"Eagerly retrieves entity history for the given entity.
Options:
* `sort-order`: `#{:asc :desc}`
* `:with-docs?` (boolean, default false): specifies whether to include documents in the entries under the `::xt/doc` key
* `:with-corrections?` (boolean, default false): specifies whether to include bitemporal corrections in the sequence, sorted first by valid-time, then tx-id
* `:start-valid-time` (inclusive, default unbounded)
* `:start-tx`: (map, all keys optional)
- `:xtdb.api/tx-time` (Date, inclusive, default unbounded)
- `:xtdb.api/tx-id` (Long, inclusive, default unbounded)
* `:end-valid-time` (exclusive, default unbounded)
* `:end-tx`: (map, all keys optional)
- `:xtdb.api/tx-time` (Date, exclusive, default unbounded)
- `:xtdb.api/tx-id` (Long, exclusive, default unbounded)
No matter what `start-*` and `end-*` parameters you specify, you won't receive results later than the valid-time and tx-id of this DB value.
Each entry in the result contains the following keys:
* `::xt/valid-time`,
* `::xt/tx-time`,
* `::xt/tx-id`,
* `::xt/content-hash`
* `::xt/doc` (see `with-docs?`).")
open-entity-history
(open-entity-history
[db eid sort-order]
[db eid sort-order opts]
"Lazily retrieves entity history for the given entity.
Don't forget to close the cursor when you've consumed enough history!
Consuming after the cursor is closed is undefined (e.g. may cause a JVM
segfault crash when using RocksDB). Therefore, be cautious with lazy
evaluation. See `entity-history` for all the options")
db-basis
(db-basis [db]
"returns the basis of this db snapshot - a map containing `::xt/valid-time` and `::xt/tx`"))
valid-time
(valid-time [db]
"returns the valid time of the db.
If valid time wasn't specified at the moment of the db value retrieval
then valid time will be time of the latest transaction.")
transaction-time
(transaction-time [db]
"returns the time of the latest transaction applied to this db value.
If a tx time was specified when db value was acquired then returns
the specified time."))
with-tx
(with-tx [db tx-ops]
"Returns a new db value with the tx-ops speculatively applied.
The tx-ops will only be visible in the value returned from this function - they're not submitted to the cluster, nor are they visible to any other database value in your application.
If the transaction doesn't commit (eg because of a failed 'match'), this function returns nil.")
Lifecycle members
start-node
(defn start-node ^IXtdb [options])
requires any dependencies on the classpath that the XTDB modules may need. |
Accepts a map, or a JSON/EDN file or classpath resource.
See https://xtdb.com/reference/configuration.html for details.
Returns a node which implements IXtdb and java.io.Closeable.
Latter allows the node to be stopped by calling (.close node)
.
Throws IndexVersionOutOfSyncException if the index needs rebuilding.
new-api-client
(defn new-api-client ^IXtdb [url])
Creates a new remote API client IXtdb.
The remote client requires valid and transaction time to be specified for all calls to db
.
Requires either clj-http or http-kit on the classpath, See https://xtdb.com/reference/http.html for more information. |
Param url
the URL to an XTDB HTTP end-point.
Returns a remote API client.
new-submit-client
(defn new-submit-client ^IXtdbSubmitClient [options])
Starts a submit client for transacting into XTDB without running a full local node with index.
Accepts a map, or a JSON/EDN file or classpath resource.
For valid options, see https://xtdb.com/reference/configuration.html.
Returns a xtdb.api.IXtdbSubmitClient component that implements java.io.Closeable.
Latter allows the node to be stopped by calling (.close node)
.