mautrix-signal/pkg/libsignalgo/storeutil.go

// mautrix-signal - A Matrix-signal puppeting bridge.
// Copyright (C) 2023 Sumner Evans
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package libsignalgo

/*
#include "./libsignal-ffi.h"
*/
import "C"
import (
	"context"
	"errors"
	"unsafe"

	gopointer "github.com/mattn/go-pointer"
)

type WrappedStore[T any] struct {
	Store T
	Ctx   *CallbackContext
}

type CallbackContext struct {
	Error  error
	Ctx    context.Context
	Unrefs []unsafe.Pointer
}

func NewCallbackContext(ctx context.Context) *CallbackContext {
	if ctx == nil {
		panic(errors.New("nil context passed to NewCallbackContext"))
	}
	return &CallbackContext{Ctx: ctx}
}

func (ctx *CallbackContext) Unref() {
	for _, ptr := range ctx.Unrefs {
		gopointer.Unref(ptr)
	}
}

func wrapStore[T any](ctx *CallbackContext, store T) unsafe.Pointer {
	wrappedStore := gopointer.Save(&WrappedStore[T]{Store: store, Ctx: ctx})
	ctx.Unrefs = append(ctx.Unrefs, wrappedStore)
	return wrappedStore
}

func wrapStoreCallbackCustomReturn[T any](storeCtx unsafe.Pointer, callback func(store T, ctx context.Context) (int, error)) C.int {
	wrap := gopointer.Restore(storeCtx).(*WrappedStore[T])
	retVal, err := callback(wrap.Store, wrap.Ctx.Ctx)
	if err != nil {
		wrap.Ctx.Error = err
	}
	return C.int(retVal)
}

func wrapStoreCallback[T any](storeCtx unsafe.Pointer, callback func(store T, ctx context.Context) error) C.int {
	wrap := gopointer.Restore(storeCtx).(*WrappedStore[T])
	if err := callback(wrap.Store, wrap.Ctx.Ctx); err != nil {
		wrap.Ctx.Error = err
		return -1
	}
	return 0
}