Json
An embedded JSON document store. Inserts stream their input, searches return lazily read results (SPEC.md). This is the store's writer, which holds the directory's lock until it's closed, with the read operations of ReadableJsonStore; other processes can read the store beside it with openSecondary. After a failed write or sync, operations throw EngineFailedException until the store is reopened (SPEC.md §8).
Inserts of any size run concurrently: small documents are logged together in group commits, large ones stream to lanes of their own, so a huge or slow insert doesn't hold up small ones. Memory stays within the store's budgets whatever the document sizes; when indexes can't be flushed as fast as documents arrive, inserts wait (SPEC.md §8).
Objects can carry a type name (SPEC.md §6), given with the insert as JSON paths or assigned later. Types are metadata: they never change the stored JSON.
Documents are never changed in place: to change one, replace it, which inserts the new version and deletes the old one in one atomic change (SPEC.md §7.1).
Stored values and JSON text can be compared for equality or diffed (SPEC.md §9), however large they are.
Types
Three ways to get a store's writer, one per intent, so that a mistyped path never quietly becomes a new, empty store: open for a store that exists, create for a new one, and openOrCreate where either will do. And openSecondary to read a store beside its writer.
Properties
What this store was created with; fixed for its life (see CreationOptions).
Functions
Applies assignments in order as one atomic change; a later assignment to the same object sees the earlier ones. When one of them fails the checks of assignType, nothing changes.
The same store without coroutines: a view that shares this store's state, valid until this store is closed. The view has no close of its own; closing this store is what releases it.
Removes type from every object that has it, as one atomic change, and returns how many objects lost it; returns once the change is acknowledged. Every object that has the type when the change is applied loses it, so none of those typed by operations acknowledged before the call keeps it. The name stays in listTypes. The call holds 32 bytes per object of the type while it runs. Throws InvalidTypeNameException for an invalid name.
How many documents the key-order search returns for query, counting no further than atMost; see the other count.
How many hits the JSONPath search returns for query, counting no further than atMost; see the other count.
How many hits search returns for query on the current state, counting no further than atMost (SPEC.md §4.7): the same candidates and matches, with the query's after, type, mode and nested-hit filter, but no hit's JSON is read, and limit and maxBytes don't apply. count(query, n) == n tells whether there are at least n hits, and stops at the n-th. Refuses what search refuses; a negative atMost throws IllegalArgumentException.
The exact number of objects of type; reads the entry of every one of them.
Deletes the document docId with its type assignments (SPEC.md §7); returns once the delete is acknowledged. Returns true when this call deleted it, false when it was already deleted. Searches started before keep seeing the document until they're closed.
The differences between a (left) and b (right), streamed in canonical order (SPEC.md §9.3): depth first, object members by key, array elements by index. Each collection runs the comparison on one new snapshot, on the store's dispatcher, and stops after DiffOptions.maxDifferences. Errors as in isEqual, thrown when collecting.
The visible document whose key is key in a store with a CreationOptions.documentKey, or null when none is (SPEC.md §3.3); with Normalization.NFC, key is normalized first. A store without document keys throws IllegalStateException.
Inserts the JSON document read from source, which isn't closed; returns its docId once it's visible. Cancelling the call stops it at the next read of source, and nothing of the document becomes visible; once source is read to its end, the insert completes and returns even if the call is cancelled (SPEC.md §8).
Inserts the document in the file path, read as it is split; the file is opened and closed by the call.
Inserts a document given as a string; meant for small documents.
Inserts the documents of sources in order, reading each to its end (streams aren't closed). Small documents are logged in shared group commits, so bulk loads sync far less often than with one insert per document. Returns one outcome per source; a rejected document, or a replace that conflicts, doesn't stop the others. Any other error is thrown: documents whose outcome wasn't returned may or may not be visible.
Up to limit objects of type in (docId, nodePre) order from the current state, strictly after after when it's given; resume with the last one returned. Throws InvalidTypeNameException for an invalid name.
Every object of type in (docId, nodePre) order, strictly after after when it's given, as a flow. Each collection reads one new snapshot on the store's dispatcher and holds it until the collection ends, so what one collection emits is consistent: the objects of the type as the operations acknowledged before it started left them. Throws InvalidTypeNameException for an invalid name, when collecting.
Up to limit objects of type in (docId, nodePre) order from the current state, strictly after after when it's given, and where the next page starts: TypePage.cursor, null when no objects were left. Only the cursor of a TypePage resumes it, anything else throws InvalidCursorException.
Inserts the JSON document read from source as insert does, and deletes the documents of docIds in the same atomic change (SPEC.md §7.1): once it's acknowledged the new document is visible and they are deleted, and a crash leaves either both or neither. Returns the new document's docId.
replace with the document given as a string; meant for small documents.
Starts a search of documents in key order (SPEC.md §3.3) on the current state; close the result when done. A store without document keys throws IllegalStateException.
Starts a JSONPath search on the current state (SPEC.md §10.4): the distinct nodes the query selects from every document, in the query's order of (docId, nodePre). Close the result when done.
Starts a search on the current state, reading on the caller's thread; close the result when done. A search the index controls of CreationOptions leave unanswerable throws QueryRejectedException with QueryRejectedException.Reason.NOT_INDEXED (SPEC.md §4.6).
Inserts the JSON document read from source as insert does, in a store with a CreationOptions.documentKey, and deletes the visible document with the same key, if there is one, in the same atomic change (SPEC.md §3.3): once it's acknowledged the new document is visible and the old one deleted, and a crash leaves either both or neither. Of two upserts of one key, the one acknowledged last wins. Returns the new document's docId.
upsert with the document given as a string; meant for small documents.
Reads everything the store can read back and reports what doesn't check out (SPEC.md §8): record and block checksums, the fragments each COMMIT still in the log names, and every fragment-index entry against the record it locates. Nothing is changed or repaired.