diff options
Diffstat (limited to 'vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go')
| -rw-r--r-- | vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go | 97 |
1 files changed, 81 insertions, 16 deletions
diff --git a/vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go b/vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go index a809ff120..a0a199ca1 100644 --- a/vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go +++ b/vendor/codeberg.org/gruf/go-ffmpreg/wasm/funcs.go @@ -9,22 +9,93 @@ import ( type snapshotskey struct{} +type snapshotctx struct { + context.Context + snaps *snapshots +} + +func (ctx snapshotctx) Value(key any) any { + if _, ok := key.(snapshotskey); ok { + return ctx.snaps + } + return ctx.Context.Value(key) +} + +const ringsz uint = 8 + +type snapshots struct { + r [ringsz]struct { + eptr uint32 + snap experimental.Snapshot + } + n uint +} + +func (s *snapshots) get(envptr uint32) experimental.Snapshot { + start := (s.n % ringsz) + + for i := start; i != ^uint(0); i-- { + if s.r[i].eptr == envptr { + snap := s.r[i].snap + s.r[i].eptr = 0 + s.r[i].snap = nil + s.n = i - 1 + return snap + } + } + + for i := ringsz - 1; i > start; i-- { + if s.r[i].eptr == envptr { + snap := s.r[i].snap + s.r[i].eptr = 0 + s.r[i].snap = nil + s.n = i - 1 + return snap + } + } + + panic("snapshot not found") +} + +func (s *snapshots) set(envptr uint32, snapshot experimental.Snapshot) { + start := (s.n % ringsz) + + for i := start; i < ringsz; i++ { + switch s.r[i].eptr { + case 0, envptr: + s.r[i].eptr = envptr + s.r[i].snap = snapshot + s.n = i + return + } + } + + for i := uint(0); i < start; i++ { + switch s.r[i].eptr { + case 0, envptr: + s.r[i].eptr = envptr + s.r[i].snap = snapshot + s.n = i + return + } + } + + panic("snapshots full") +} + // withSetjmpLongjmp updates the context to contain wazero/experimental.Snapshotter{} support, // and embeds the necessary snapshots map required for later calls to Setjmp() / Longjmp(). func withSetjmpLongjmp(ctx context.Context) context.Context { - snapshots := make(map[uint32]experimental.Snapshot, 10) - ctx = experimental.WithSnapshotter(ctx) - ctx = context.WithValue(ctx, snapshotskey{}, snapshots) - return ctx + return snapshotctx{Context: experimental.WithSnapshotter(ctx), snaps: new(snapshots)} } -func getSnapshots(ctx context.Context) map[uint32]experimental.Snapshot { - v, _ := ctx.Value(snapshotskey{}).(map[uint32]experimental.Snapshot) +func getSnapshots(ctx context.Context) *snapshots { + v, _ := ctx.Value(snapshotskey{}).(*snapshots) return v } // setjmp implements the C function: setjmp(env jmp_buf) -func setjmp(ctx context.Context, mod api.Module, stack []uint64) { +func setjmp(ctx context.Context, _ api.Module, stack []uint64) { // Input arguments. envptr := api.DecodeU32(stack[0]) @@ -35,19 +106,16 @@ func setjmp(ctx context.Context, mod api.Module, stack []uint64) { // Get stored snapshots map. snapshots := getSnapshots(ctx) - if snapshots == nil { - panic("setjmp / longjmp not supported") - } // Set latest snapshot in map. - snapshots[envptr] = snapshot + snapshots.set(envptr, snapshot) // Set return. stack[0] = 0 } // longjmp implements the C function: int longjmp(env jmp_buf, value int) -func longjmp(ctx context.Context, mod api.Module, stack []uint64) { +func longjmp(ctx context.Context, _ api.Module, stack []uint64) { // Input arguments. envptr := api.DecodeU32(stack[0]) @@ -60,10 +128,7 @@ func longjmp(ctx context.Context, mod api.Module, stack []uint64) { } // Get snapshot stored in map. - snapshot := snapshots[envptr] - if snapshot == nil { - panic("must first call setjmp") - } + snapshot := snapshots.get(envptr) // Set return. stack[0] = 0 |