Module ffi 

C FFI layer for LaminarDB.

Enable with the ffi feature flag:

laminar-db = { version = "0.1", features = ["ffi"] }

This module provides extern "C" functions for calling LaminarDB from C and any language with C FFI support (Python, Java, Node.js, .NET, etc.). C FFI layer for LaminarDB.

Structs

LaminarConnection

Opaque connection handle. Create with laminar_open, free with laminar_close.

LaminarQueryResult

Opaque handle for materialized query results.

LaminarQueryStream

Opaque handle for streaming query results.

LaminarRecordBatch

Opaque Arrow RecordBatch handle. Free with laminar_batch_free.

LaminarSchema

Opaque schema handle for FFI.

LaminarSubscriptionHandle

Opaque handle for a callback-based subscription.

LaminarWriter

Opaque writer handle for FFI.

Constants

LAMINAR_ERR_CONNECTION

Connection error.

LAMINAR_ERR_INGESTION

Data ingestion error.

LAMINAR_ERR_INTERNAL

Internal error.

LAMINAR_ERR_INVALID_UTF8

Invalid UTF-8 string.

LAMINAR_ERR_NULL_POINTER

Null pointer was passed to a function.

LAMINAR_ERR_QUERY

Query execution error.

LAMINAR_ERR_SCHEMA_MISMATCH

Schema mismatch error.

LAMINAR_ERR_SHUTDOWN

Database is shutting down.

LAMINAR_ERR_SUBSCRIPTION

Subscription error.

LAMINAR_ERR_TABLE_EXISTS

Table/source already exists.

LAMINAR_ERR_TABLE_NOT_FOUND

Table/source not found.

LAMINAR_EVENT_DELETE

Event type: delete (-1 weight).

LAMINAR_EVENT_INSERT

Event type: insert (+1 weight).

LAMINAR_EVENT_SNAPSHOT

Event type: initial-state snapshot.

LAMINAR_EVENT_UPDATE

Event type: update (delete + insert pair).

LAMINAR_EVENT_WATERMARK

Event type: watermark progress.

LAMINAR_OK

Success return code.

Functions

laminar_batch_create^⚠

Alias for laminar_batch_import for use when creating data for writing.

laminar_batch_export^⚠

Export a RecordBatch to the Arrow C Data Interface.

laminar_batch_export_column^⚠

Export a single column from a RecordBatch to the Arrow C Data Interface.

laminar_batch_free^⚠

Free a record batch handle.

laminar_batch_import^⚠

Import a RecordBatch from the Arrow C Data Interface, taking ownership of both structs.

laminar_batch_num_columns^⚠

Get the number of columns in a record batch.

laminar_batch_num_rows^⚠

Get the number of rows in a record batch.

laminar_clear_error

Clear the last error.

laminar_close^⚠

Close a database connection and free all associated resources.

laminar_execute^⚠

Execute a SQL statement. For DDL, out may be NULL.

laminar_get_schema^⚠

Get schema for a source.

laminar_is_closed^⚠

Check if the connection is closed.

laminar_last_error

Get the last error message as a null-terminated string, or null if no error.

laminar_last_error_code

Get the last error code, or LAMINAR_OK if none.

laminar_list_sources^⚠

List all sources as a JSON array (e.g., ["src1","src2"]). Caller frees with laminar_string_free.

laminar_open^⚠

Open a new database connection.

laminar_query^⚠

Execute a query and collect all results into memory.

laminar_query_stream^⚠

Execute a query with streaming results.

laminar_result_free^⚠

Free a query result handle.

laminar_result_get_batch^⚠

Get a batch by index from a query result.

laminar_result_num_batches^⚠

Get the number of batches in a query result.

laminar_result_num_rows^⚠

Get the total row count from a query result.

laminar_result_schema^⚠

Get the schema from a query result.

laminar_schema_export^⚠

Export just the schema to the Arrow C Data Interface.

laminar_schema_field_name^⚠

Get the name of a field by index. Caller frees the result with laminar_string_free.

laminar_schema_field_type^⚠

Get the Arrow data type of a field by index as a string. Caller frees with laminar_string_free.

laminar_schema_free^⚠

Free a schema handle.

laminar_schema_num_fields^⚠

Get the number of fields in a schema.

laminar_start^⚠

Start the streaming pipeline.

laminar_stream_cancel^⚠

Cancel a query stream.

laminar_stream_free^⚠

Free a query stream handle.

laminar_stream_is_active^⚠

Check if a query stream is still active.

laminar_stream_next^⚠

Get the next batch from a query stream (blocking). Sets *out to NULL when exhausted.

laminar_stream_schema^⚠

Get the schema from a query stream.

laminar_stream_try_next^⚠

Try to get the next batch from a query stream (non-blocking). Sets *out to NULL if none available.

laminar_string_free^⚠

Free a string allocated by a laminar function.

laminar_subscribe_callback^⚠

Create a callback-based subscription; on_data is called from a background thread.

laminar_subscription_cancel^⚠

Cancel a callback-based subscription; no callbacks will fire after this returns.

laminar_subscription_free^⚠

Free a subscription handle, cancelling it first if still active.

laminar_subscription_is_active^⚠

Check if a subscription is still active.

laminar_subscription_user_data^⚠

Return the user data pointer from a subscription handle, or NULL.

laminar_version

Return the library version as a static null-terminated string (do not free).

laminar_writer_close^⚠

Close the writer. The handle may still be freed with laminar_writer_free afterward.

laminar_writer_create^⚠

Create a writer for a source.

laminar_writer_flush^⚠

Flush buffered data.

laminar_writer_free^⚠

Free a writer handle.

laminar_writer_write^⚠

Write a record batch to the source. Ownership of batch is transferred.

Type Aliases

LaminarErrorCallback

Callback invoked when a subscription error occurs.

LaminarSubscriptionCallback

Callback invoked from the subscription thread with each batch.