Module adapter_common 

Shared helpers reused by every loader adapter crate.

Each of uni-plugin-wasm, uni-plugin-extism, uni-plugin-pyo3, uni-plugin-rhai, and uni-plugin-custom previously reimplemented Arrow type mapping, single-row RecordBatch construction, and a manifest JSON round-trip on the Loader::load path. This module hosts the consolidated versions.

Submodules

• arrow_types — ArgType → DataType and wire-name → DataType mapping shared by every loader. Replaces four duplicated copies of argtype_arrow and two copies of arrow_name_to_dt / arrow_name_to_datatype.
• batch_builder — single-row RecordBatch + one-item SendableRecordBatchStream builders.

Pool factory unification is not part of this module — the wasm loader unifies its three internal factories via a crate-local WasmInstanceFactory trait, and the extism loader keeps its single factory. Pulling the factory shape into uni-plugin would require the trait to be parameterized over wasmtime / extism types, which would in turn force feature-gated re-exports here. Per §1.1’s “ship what unifies cleanly, leave the rest” guidance, generic pool unification is deferred.

The manifest JSON round-trip is removed by adding a prepare_parsed entry point to each loader (Loader::prepare_parsed(manifest, grants)) and routing Loader::load through it; the public Loader::prepare(json_bytes, grants) is preserved for test and external use.

Stability

Helpers exported here are considered loader-internal — they live in uni-plugin so the dependency graph stays acyclic, not because out-of-tree code is expected to call them.

Modules

arrow_types

ArgType ⇄ Arrow DataType mapping shared by every loader adapter.

batch_builder

Single-row RecordBatch / stream builders shared by loader adapters.