// 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/>.

package cmd

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"strings"
	"testing"
)

// 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/>.

package lsync

import (
	"context"
	"math"
	"math/rand"
	"sync"
	"time"
)

/*
 * Copyright 2023 the original author or authors.
 *
 * 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,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * 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,

// These will be chosen before others.
func (p *parallelReader) preferReaders(prefer []bool) {
	if len(prefer) != len(p.orgReaders) {
		return
	}
	// Copy so we don't change our input.
	tmp := make([]io.ReaderAt, len(p.orgReaders))
	copy(tmp, p.orgReaders)
	p.readers = tmp
	// next is the next non-preferred index.
	next := 0
	for i, ok := range prefer {
		if !ok || p.readers[i] == nil {
			continue
		}

然后再用它生成一个只含已设置（在请求中所发送）数据，且省略了默认值的 `dict`：

{* ../../docs_src/body_updates/tutorial002.py hl[34] *}

### 使用 Pydantic 的 `update` 参数

接下来，用 `.copy()` 为已有模型创建调用 `update` 参数的副本，该参数为包含更新数据的 `dict`。

例如，`stored_item_model.copy(update=update_data)`：

{* ../../docs_src/body_updates/tutorial002.py hl[35] *}

### 更新部分数据小结

简而言之，更新部分数据应：

* 使用 `PATCH` 而不是 `PUT` （可选，也可以用 `PUT`）；
* 提取存储的数据；

/// info | Информация

В Pydantic v1 метод назывался `.copy()`, в Pydantic v2 он помечен как устаревший (но все еще поддерживается) и переименован в `.model_copy()`.

Примеры здесь используют `.copy()` для совместимости с Pydantic v1, но если вы можете использовать Pydantic v2, лучше используйте `.model_copy()`.

///

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * 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,

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * 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,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * 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,