datafusion-examples/examples/ffi/ffi_module_interface/src/lib.rs

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// to you under the Apache License, Version 2.0 (the
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//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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use abi_stable::{
    StableAbi, declare_root_module_statics,
    library::{LibraryError, RootModule},
    package_version_strings,
    sabi_types::VersionStrings,
};
use datafusion_ffi::proto::logical_extension_codec::FFI_LogicalExtensionCodec;
use datafusion_ffi::table_provider::FFI_TableProvider;

#[repr(C)]
#[derive(StableAbi)]
#[sabi(kind(Prefix(prefix_ref = TableProviderModuleRef)))]
/// This struct defines the module interfaces. It is to be shared by
/// both the module loading program and library that implements the
/// module. It is possible to move this definition into the loading
/// program and reference it in the modules, but this example shows
/// how a user may wish to separate these concerns.
pub struct TableProviderModule {
    /// Constructs the table provider
    pub create_table:
        extern "C" fn(codec: FFI_LogicalExtensionCodec) -> FFI_TableProvider,
}

impl RootModule for TableProviderModuleRef {
    declare_root_module_statics! {TableProviderModuleRef}
    const BASE_NAME: &'static str = "ffi_example_table_provider";
    const NAME: &'static str = "ffi_example_table_provider";
    const VERSION_STRINGS: VersionStrings = package_version_strings!();

    fn initialization(self) -> Result<Self, LibraryError> {
        Ok(self)
    }
}