forked from caoXF/curve
322 lines
8.9 KiB
Markdown
322 lines
8.9 KiB
Markdown
[中文版](../cn/curve-client-python-api.md)
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#### Get a CBDClient object that interacts with the Curve cluster
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```python
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import curvefs
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# Get a CBDClient object that interacts with the back-end cluster. Different CBDClient objects can establish connections with different clusters
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cbd1 = curvefs.CBDClient()
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cbd2 = curvefs.CBDClient()
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```
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#### CBDClient initialization
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```python
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import curvefs
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cbd = curvefs.CBDClient()
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# parameter: full path of curve-client configuration file
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# return: return 0 if initialized successfully, -1 means failed
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cbd.Init("/etc/curve/client.conf")
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```
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#### Create file
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```python
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import curvefs
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cbd = curvefs.CBDClient()
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cbd.Init("/etc/curve/client.conf") # subsequent examples omit the initialization process
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# parameter: the three parameters are
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# file full path
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# user information
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# file size
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# return: return 0 if create successfully, otherwise return an error code
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# First initialize user information (the control plane interfaces of curvefs have user information verification, and user information needs to be passed in)
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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user.password = "" # when the password is empty, it can be omitted
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# Create a file with Create interface
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cbd.Create("/curve", user, 10*1024*1024*1024)
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# UserInfo definition
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typedef struct UserInfo {
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char owner[256]; # username
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char password[256]; # password
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} UserInfo_t;
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```
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#### Get file information
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```python
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# parameter: the three parameters are
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# filename
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# user information
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# fileInfo[exit parameter]
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# return: return 0 if get successfully, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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# Construct file information
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finfo = curvefs.FileInfo_t()
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# Get file information
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cbd.StatFile("/curve", user, finfo)
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print finfo.filetype
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print finfo.length
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print finfo.ctime
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# FileInfo definition
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typedef struct FileInfo {
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uint64_t id;
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uint64_t parentid;
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int filetype; # volume type
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uint64_t length; # volume size
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uint64_t ctime; # volume create time
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char filename[256]; # volume name
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char owner[256]; # volume owner
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int fileStatus; # volume status
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} FileInfo_t;
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# File status
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#define CURVE_FILE_CREATED 0
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#define CURVE_FILE_DELETING 1
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#define CURVE_FILE_CLONING 2
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#define CURVE_FILE_CLONEMETAINSTALLED 3
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#define CURVE_FILE_CLONED 4
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#define CURVE_FILE_BEINGCLONED 5
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```
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#### Extend file
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```python
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# parameter: the three parameters are
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# filename
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# user information
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# file size after extend
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# return: return 0 if extend successfully, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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# Extend
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cbd.Extend("/curve", user, 20*1024*1024*1024)
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# Get file information after extension
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finfo = curvefs.FileInfo_t()
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cbd.StatFile("/curve", user, finfo)
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print finfo.length
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```
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#### Open/Close file
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```python
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# Open file
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# parameter: the two parameters are
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# filename
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# user information
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# return: return fd if open successfully, otherwise return error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "user1"
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# Open file，return fd
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fd = cbd.Open("/tmp1", user)
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# Close file
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# parameter: fd returned when opening the file
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# return: return 0 if closed successfully, otherwise return an error code
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cbd.Close(fd)
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```
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#### Read and write file
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```python
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# Write file
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# parameter: the four parameters are
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# fd
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# data to write
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# offset
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# date length
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# return: return the number of bytes written If write successful, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "user1"
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# Open file，return fd
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fd = cbd.Open("/tmp1", user)
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# Write files (Currently, 4k alignment is required for reading and writing)
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cbd.Write(fd, "aaaaaaaa"*512, 0, 4096)
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cbd.Write(fd, "bbbbbbbb"*512, 4096, 4096)
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# Read file
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# parameter: the four parameters are
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# fd
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# null string
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# offset
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# data length to read
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# return: return read data if read successfully, otherwise return an error code
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# The read content is returned by the return value, buf is not needed, you can pass in an empty string
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cbd.Read(fd，"", 0, 4096)
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# Close file
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cbd.Close(fd)
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```
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Note: The current python api does not support asynchronous reading and writing
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#### Delete file
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```python
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# parameter: the two parameters are
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# filename
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# user information
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# return: return 0 if delete successfully, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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# Delete file
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cbd.Unlink("/curve", user)
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```
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#### Recover file
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```python
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# parameter: the three parameters are
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# filename
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# user information
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# file id (optional, default is 0)
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# return: return 0 if recover successfully, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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# Recover file
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cbd.Recover("/curve", user, 0)
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```
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#### Rename file
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```python
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# parameter: the three parameters are
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# user information
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# old filename
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# new filename
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# return: return 0 if rename successfully, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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# Rename
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cbd.Rename(user, "/curve", "/curve-new")
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```
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#### Create a directory
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```python
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# parameter: the two parameters are
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# directory path
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# user information
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# return: return 0 if create successfully, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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# Create directory
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cbd.Mkdir("/curvedir", user)
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```
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#### Delete directory
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```python
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# parameter: the two parameters are
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# directory path
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# user information
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# return: return 0 if create successfully, otherwise return an error code
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# Construct user information
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user = curvefs.UserInfo_t()
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user.owner = "curve"
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# Delete directory
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cbd.Rmdir("/curvedir", user)
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```
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#### List the files in the directory
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```python
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# parameter: the two parameters are
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# directory path
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# user information
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# return: files in the directory (only filename)
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files = cbd.Listdir("/test", user)
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for f in files:
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print f
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```
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#### Get the cluster ID
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```python
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# Determine whether this get is successful by the return value
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# success: return cluster ID
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# fail: return null string
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clusterId = cbd.GetClusterId()
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print clusterId
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# c355675a-f4d2-4729-b80a-5a7bcc749d1c
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```
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#### Clean CBDClient object
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```python
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cbd.UnInit()
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```
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### Error code
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| Code | Message | description |
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| :--: | :-------------------------- | ------------------------ |
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| 0 | OK | success |
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| -1 | EXISTS | file or directory exists |
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| -2 | FAILED | fail |
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| -3 | DISABLEDIO | disable io |
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| -4 | AUTHFAIL | authentication failed |
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| -5 | DELETING | deleting |
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| -6 | NOTEXIST | file not exist |
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| -7 | UNDER_SNAPSHOT | under snapshot |
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| -8 | NOT_UNDERSNAPSHOT | not under snapshot |
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| -9 | DELETE_ERROR | delete error |
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| -10 | NOT_ALLOCATE | segment not allocated |
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| -11 | NOT_SUPPORT | operation not supported |
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| -12 | NOT_EMPTY | directory not empty |
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| -13 | NO_SHRINK_BIGGER_FILE | no shrinkage |
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| -14 | SESSION_NOTEXISTS | session not exist |
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| -15 | FILE_OCCUPIED | file occupied |
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| -16 | PARAM_ERROR | parameter error |
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| -17 | INTERNAL_ERROR | internal error |
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| -18 | CRC_ERROR | CRC error |
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| -19 | INVALID_REQUEST | parameter invalid |
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| -20 | DISK_FAIL | disk fail |
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| -21 | NO_SPACE | no space |
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| -22 | NOT_ALIGNED | io not aligned |
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| -23 | BAD_FD | file is being closed, fd unavailable |
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| -24 | LENGTH_NOT_SUPPORT | file length is not supported |
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| -25 | SESSION_NOT_EXIST | session not exist, duplicate with -14 |
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| -26 | STATUS_NOT_MATCH | status error |
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| -27 | DELETE_BEING_CLONED | delete the file being cloned |
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| -28 | CLIENT_NOT_SUPPORT_SNAPSHOT | this version of client not support snapshot |
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| -29 | SNAPSHOT_FROZEN | snapshot is disabled |
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| -100 | UNKNOWN | unknown error |
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