如何在 Go 中构建递归的结构切片？

Question

我需要从一段字符串创建一个 JSON 有效负载。它们代表单个文件的路径。它们需要合并成代表整个目录结构的最终 JSON 负载。

如果字符串如下：

[
    "alpha/file1.json"
    "alpha/beta/file2.json"
    "alpha/beta/charlie/file3.json"
    "alpha/beta/charlie/file4.json"
    "delta/file5.json
]

JSON 负载结构

• 目录结构应包含名称，包含子项和/或文件。
• 子项将代表另一个目录结构及其自己的文件
• Files 代表目录中的文件

JSON 负载是这样的：

[{
    "Name": "alpha",
    "Files": [{
        "Name": "file1.json",
        "Path": "alpha/file1.json"
    }],
    "Children": [{
        "Name": "beta",
        "Files": [{
            "Name": "file2.json",
            "Path": "alpha/beta/file2.json"
        }],
        "Children": [{
            "Name": "charlie",
            "Files": [{
                "Name": "file3.json",
                "Path": "alpha/beta/charlie/file3.json"
            },
            {
                "Name": "file4.json",
                "Path": "alpha/beta/charlie/file4.json"
            }]
        }]
    }]
},{
    "Name": "delta",
    "Files": [
        {
            "Name": "file5.json",
            "Path": "delta/file5.json"
        }
    ]
}]

我不知道如何确定目录名称是否已经存在，如果存在则将指针传递给该目录。目前，它为每个文件路径附加一个新的目录结构到基本切片。以下是我到目前为止所得到的。

https://play.golang.org/p/WoNEcJLe51z

Answer 1

我需要创建一个函数来返回切片中现有文件夹的索引。然后递归它的孩子。

// DirectoryStructure stores the directory structure
type DirectoryStructure struct {
    Name     string               `json:"Name"`
    Children []DirectoryStructure `json:"Children,omitempty"`
    Files    []File               `json:"Files,omitempty"`
}

// File stores the name of file and path to file
type File struct {
    Name string `json:"Name"`
    Path string `json:"Path"`
}

func main() {
    // Build slice of strings
    filePaths := []string{}
    filePaths = append(filePaths, "alpha/file1.json")
    filePaths = append(filePaths, "alpha/beta/file2.json")
    filePaths = append(filePaths, "alpha/beta/charlie/file3.json")
    filePaths = append(filePaths, "alpha/beta/charlie/file4.json")
    filePaths = append(filePaths, "delta/file5.json")

    // Create directory with slice of structs
    directory := []DirectoryStructure{}

    // Iterate through slice
    for _, path := range filePaths {
        pathSlice := strings.Split(path, "/")
        // Start recursive function. Passing directory and assigning it to itself
        directory = buildDirectory(pathSlice, path, directory)
    }

    b, err := json.Marshal(directory)
    if err != nil {
        fmt.Println(err)
        return
    }

    fmt.Println(string(b))
}

func buildDirectory(path []string, key string, directory []DirectoryStructure) []DirectoryStructure {
    // Return index of folder if it already exists.
    folderIndex := doesExist(path[0], directory)
    // If folder exists and the next value in the path slice is not the file
    if folderIndex > -1 && len(path) != 2 {
        // Pass existing folder's Children to buildDirectory function and assign to itself
        directory[folderIndex].Children = buildDirectory(path[1:], key, directory[folderIndex].Children)
        return directory
    }
    // If next value in the path slice is a file
    if len(path) == 2 {
        // If folder does not exist
        if folderIndex == -1 {
            // Create new folder with files inside and append to directory
            fileDirectory := DirectoryStructure{}
            fileDirectory.Files = []File{{path[1], string(key)}}
            fileDirectory.Name = path[0]
            directory = append(directory, fileDirectory)
        } else {
            // If folder does exist, append files to the directory
            directory[folderIndex].Files = append(directory[folderIndex].Files, File{path[1], string(key)})
        }
        return directory
    }
    // Folder does not exist and the next value is not a file
    // Create new directory, recurse it's Children, and append when returned
    currentDirectory := DirectoryStructure{}
    currentDirectory.Name = path[0]
    currentDirectory.Children = buildDirectory(path[1:], key, []DirectoryStructure{})
    directory = append(directory, currentDirectory)
    return directory

}

// doesExist returns index of folder if exists
func doesExist(folderName string, directory []DirectoryStructure) int {
    for index, element := range directory {
        if folderName == element.Name {
            return index
        }
    }
    return -1
}