// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
//
// 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 image

import (
	"context"
	"io"
)

// contextInput 在读取图像编码时检查调用方取消状态
type contextInput struct {
	io.ReadCloser
	ctx context.Context
}

// Read 检查取消状态后读取原始数据
// 入参: data 数据缓冲区
// 返回: int 读取字节数, error 读取或取消错误
func (r contextInput) Read(data []byte) (int, error) {
	if err := r.ctx.Err(); err != nil {
		return 0, err
	}
	return r.ReadCloser.Read(data)
}