gotosocial/internal/media/ffmpeg/wasm.go
kim 6a76b9d609
[feature/OFFICIALLY UNSUPPORTED] add nowasm build tag to disable building with WebAssembly (#3429)
* add experimental build-tag 'nowasm' which uses local ffmpeg / ffprobe

* updated experimental support message

* add comment to build script explaining build tag

* add nowasm build tags to moderncsqlite files
2024-10-14 11:59:12 +02:00

129 lines
3.2 KiB
Go

// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// 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 <http://www.gnu.org/licenses/>.
//go:build !nowasm
package ffmpeg
import (
"context"
"os"
ffmpeglib "codeberg.org/gruf/go-ffmpreg/embed/ffmpeg"
ffprobelib "codeberg.org/gruf/go-ffmpreg/embed/ffprobe"
"codeberg.org/gruf/go-ffmpreg/wasm"
"github.com/tetratelabs/wazero"
"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
)
// Use all core features required by ffmpeg / ffprobe
// (these should be the same but we OR just in case).
const corefeatures = wasm.CoreFeatures
var (
// shared WASM runtime instance.
runtime wazero.Runtime
// ffmpeg / ffprobe compiled WASM.
ffmpeg wazero.CompiledModule
ffprobe wazero.CompiledModule
)
// compileFfmpeg ensures the ffmpeg WebAssembly has been
// pre-compiled into memory. If already compiled is a no-op.
func compileFfmpeg(ctx context.Context) error {
if ffmpeg != nil {
return nil
}
// Ensure runtime already initialized.
if err := initRuntime(ctx); err != nil {
return err
}
// Compile the ffmpeg WebAssembly module into memory.
cmod, err := runtime.CompileModule(ctx, ffmpeglib.B)
if err != nil {
return err
}
// Set module.
ffmpeg = cmod
return nil
}
// compileFfprobe ensures the ffprobe WebAssembly has been
// pre-compiled into memory. If already compiled is a no-op.
func compileFfprobe(ctx context.Context) error {
if ffprobe != nil {
return nil
}
// Ensure runtime already initialized.
if err := initRuntime(ctx); err != nil {
return err
}
// Compile the ffprobe WebAssembly module into memory.
cmod, err := runtime.CompileModule(ctx, ffprobelib.B)
if err != nil {
return err
}
// Set module.
ffprobe = cmod
return nil
}
// initRuntime initializes the global wazero.Runtime,
// if already initialized this function is a no-op.
func initRuntime(ctx context.Context) error {
if runtime != nil {
return nil
}
var cache wazero.CompilationCache
if dir := os.Getenv("GTS_WAZERO_COMPILATION_CACHE"); dir != "" {
var err error
// Use on-filesystem compilation cache given by env.
cache, err = wazero.NewCompilationCacheWithDir(dir)
if err != nil {
return err
}
}
// Prepare config with cache.
cfg := wazero.NewRuntimeConfig()
cfg = cfg.WithCoreFeatures(corefeatures)
cfg = cfg.WithCompilationCache(cache)
// Instantiate runtime with prepared config.
rt := wazero.NewRuntimeWithConfig(ctx, cfg)
// Instantiate wasi snapshot preview features into runtime.
_, err := wasi_snapshot_preview1.Instantiate(ctx, rt)
if err != nil {
return err
}
// Set runtime.
runtime = rt
return nil
}