Installation

Add the Go API to your project:

go get github.com/MetaFFI/sdk/api/go
go get github.com/MetaFFI/plugin-sdk/compiler/go/IDL

MetaFFIRuntime Struct

MetaFFIRuntime provides a simple FFI framework to connect Go with other languages. Pass the runtime plugin name to NewMetaFFIRuntime (e.g. "python3", "openjdk"), and call LoadRuntimePlugin to load the runtime.

Once the runtime is loaded, use LoadModule to load a module and receive an instance of MetaFFIModule.

Methods

NewMetaFFIRuntime(runtimePlugin string) *MetaFFIRuntime

Constructor specifying the requested runtime plugin to use.

Parameters:

  • runtimePlugin — The name of the runtime plugin (e.g. "python3", "openjdk")

(this *MetaFFIRuntime) LoadRuntimePlugin() error

Loads the runtime of the plugin.

(this *MetaFFIRuntime) ReleaseRuntimePlugin() error

Releases the loaded runtime. After calling this function, any loaded entity must not be used.

(this *MetaFFIRuntime) LoadModule(modulePath string) (*MetaFFIModule, error)

Loads a foreign module from the given modulePath. Returns a MetaFFIModule object representing the foreign module.

The modulePath may contain multiple modules separated by semicolons (for cases like dependencies). Each runtime plugin specifies in its documentation what it expects.

Parameters:

  • modulePath — Path to the module(s) to load

Returns: Instance of *MetaFFIModule

MetaFFIModule Struct

Provides the Load method, which loads a foreign entity and returns it as a func.

The struct should not be created directly — use MetaFFIRuntime.LoadModule instead.

Methods

(this *MetaFFIModule) Load(entityPath string, paramsMetaFFITypes []MetaFFIType, retvalMetaFFITypes []MetaFFIType) (func(...interface{}) ([]interface{}, error), error)

(this *MetaFFIModule) LoadWithInfo(entityPath string, paramsMetaFFITypes []MetaFFITypeInfo, retvalMetaFFITypes []MetaFFITypeInfo) (func(...interface{}) ([]interface{}, error), error)

Loads a foreign entity from the module and returns a func that invokes it.

If the entity is an instance method or field, the first parameter is the object instance (see Entity Path for the instance_required tag).

Load accepts []MetaFFIType. If alias is also required, use LoadWithInfo which accepts []MetaFFITypeInfo.

Parameters:

  • entityPath — Entity path string locating the entity within the module
  • paramsMetaFFITypes — Array of MetaFFIType (or MetaFFITypeInfo) specifying parameter types, or nil
  • retvalMetaFFITypes — Array of MetaFFIType (or MetaFFITypeInfo) specifying return types, or nil

Returns: A func(...interface{}) ([]interface{}, error) that accepts the parameters defined in paramsMetaFFITypes. Returns an error on failure.

MetaFFI Types in Go

MetaFFI Type Go Type
metaffi_float64_type float64
metaffi_float32_type float32
metaffi_int8_type int8
metaffi_int16_type int16
metaffi_int32_type int32
metaffi_int64_type int64
metaffi_uint8_type uint8
metaffi_uint16_type uint16
metaffi_uint32_type uint32
metaffi_uint64_type uint64
metaffi_bool_type bool
metaffi_char8_type uint8
metaffi_char16_type uint16
metaffi_char32_type rune
metaffi_string8_type string
metaffi_string16_type string
metaffi_string32_type string
metaffi_handle_type MetaFFIHandle
metaffi_any_type interface{}
metaffi_null_type nil
metaffi_callable_type func (not supported yet)
metaffi_float64_array_type []float64
metaffi_float32_array_type []float32
metaffi_int8_array_type []int8
metaffi_int16_array_type []int16
metaffi_int32_array_type []int32
metaffi_int64_array_type []int64
metaffi_uint8_array_type []uint8
metaffi_uint16_array_type []uint16
metaffi_uint32_array_type []uint32
metaffi_uint64_array_type []uint64
metaffi_bool_array_type []bool
metaffi_char8_array_type []uint8
metaffi_string8_array_type []string
metaffi_string16_array_type []string
metaffi_string32_array_type []string
metaffi_any_array_type []interface{}
metaffi_handle_array_type []MetaFFIHandle