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// Copyright (C) 2015 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package atom
import (
"bytes"
"android.googlesource.com/platform/tools/gpu/binary"
)
// List is a list of atoms.
type List []Atom
// WriteTo writes all atoms in the list to w, inserting EOS atoms after the last
// atom of each context.
func (l *List) WriteTo(w Writer) {
// Find the last atom index for each context
last := make(map[ContextId]int)
for i, a := range *l {
last[a.ContextId()] = i
}
// Write out the atoms, injecting EOS markers for each context.
nextEosId := Id(len(*l))
for i, a := range *l {
w.Write(Id(i), a)
ctx := a.ContextId()
if last[ctx] == i {
w.Write(nextEosId, &EOS{Context: ctx})
nextEosId++
}
}
}
// Clone makes and returns a shallow copy of the atom list.
func (l *List) Clone() List {
c := make(List, len(*l))
copy(c, *l)
return c
}
// Add adds a to the end of the atom list.
func (l *List) Add(a Atom) {
*l = append(*l, a)
}
// Add adds a to the list before the atom at id.
func (l *List) AddAt(a Atom, id Id) {
*l = append(*l, nil)
copy((*l)[id+1:], (*l)[id:])
(*l)[id] = a
}
// Encode encodes the atom list using the specified encoder.
func (l *List) Encode(e *binary.Encoder) error {
atomBuf := &bytes.Buffer{}
atomEnc := binary.NewEncoder(atomBuf)
for _, atom := range *l {
if err := atom.TypeId().Encode(atomEnc); err != nil {
return err
}
if err := atom.Encode(atomEnc); err != nil {
return err
}
atomData := atomBuf.Bytes()
if err := e.Uint16(uint16(len(atomData) + 2)); err != nil {
return err
}
if _, err := e.Write(atomData); err != nil {
return err
}
atomBuf.Reset()
}
e.Uint16(0)
return nil
}
// Encode decodes the atom list using the specified encoder.
func (l *List) Decode(d *binary.Decoder) error {
*l = List{} // Clear the list
for {
size, err := d.Uint16()
if err != nil {
return err
}
if size == 0 {
break
}
var typeId TypeId
if err := typeId.Decode(d); err != nil {
return err
}
atom, err := New(TypeId(typeId))
if err != nil {
return err
}
if err := atom.Decode(d); err != nil {
return err
}
*l = append(*l, atom)
}
return nil
}