def _hdfs_make_one_dir(arg: str) -> str:
"""
Helper function for _hdfs_mkdir(); processes a single arg (path),
returns blank str on success, string w/ error message if dir path is
invalid or already exists
"""
db = get_db()
parent_id = 1
dirs = [d for d in arg.split('/') if d != '']
for dir in dirs[:-1]:
query = """SELECT id FROM hdfs_file
WHERE f_name IS ? AND f_type IS 'd' AND f_parent_id IS ?;"""
check = db.execute(query, (dir, parent_id)).fetchone()
if check is None:
return f"hdfs dfs -mkdir: {dir}: No such directory"
parent_id = check["id"]
query = """SELECT f_name FROM hdfs_file
WHERE f_name IS ? AND f_parent_id IS ?;"""
if db.execute(query, (dirs[-1], parent_id)).fetchone() is not None:
return f"hdfs dfs -mkdir: {dirs[-1]}: File exists"
query = """INSERT INTO hdfs_file
(f_name, f_type, f_parent_id)
VALUES
(?, 'd', ?);"""
db.execute(query, (dirs[-1], parent_id))
db.commit()
return ""
def _get_valid_file_path(path: str) -> int:
"""
Validate file path and return its ID #
Args:
path: single string containing path to desired file
Returns:
file ID on success, None if path invalid
"""
dirs = [d for d in path.split('/') if d != '']
parent_id = 1
db = get_db()
check = None
for dir in dirs:
query = """SELECT id FROM hdfs_file
WHERE id IS ? AND f_type IS 'd';"""
check = db.execute(query, (parent_id, )).fetchone()
if check is None:
return None
query = """SELECT id FROM hdfs_file
WHERE f_name IS ? and f_parent_id IS ?;"""
check = db.execute(query, (dir, parent_id)).fetchone()
if check is None:
return None
parent_id = check['id']
return check['id']
def _hdfs_chown(args: str) -> List[str]:
"""
Change ownership of file in HDFS
CLI usage: `hdfs dfs -chown [username] [path/to/file]`
Args:
args: single string containing required args
Returns:
List of empty string upon success, List containing error msg on failure
"""
args = remove_spcs(args).split(' ')
if len(args) != 2:
return ["Usage: `hdfs dfs -chown [username] [path/to/file]`"]
id = _get_valid_file_path(args[1])
if id is None:
return ["sh: hdfs dfs -chown: invalid path"]
query = """UPDATE hdfs_file SET u_id = ? WHERE id = ?;"""
db = get_db()
db.execute(query, (args[0], id))
db.commit()
return [""]
def _hdfs_rm(args: str) -> List[str]:
"""
Delete file from HDFS
CLI usage: `hdfs dfs -rm path/to/file`
Args:
args: single string containing path to file to delete
Returns:
Nothing upon success, error message on failure
"""
args = remove_spcs(args)
if len(args.split(' ')) != 1:
return ["Usage: `hdfs dfs -rm path/to/file`"]
id = _get_valid_file_path(args)
if id is None:
return ["sh: hdfs dfs -rm: invalid file path"]
query = """DELETE FROM hdfs_file
WHERE id IS ?;"""
db = get_db()
db.execute(query, (id, ))
db.commit()
return [""]
def _hdfs_ls(args: str) -> List[str]:
"""
Check contents of directory in HDFS
CLI usage: `hdfs dfs -ls [/path/to/dir] ...`
Args:
args : single string containing one or more valid paths
Returns:
List of strings containing details of contents, or error msg on failure
"""
args = remove_spcs(args)
num_args = len([i for i in args.split(' ') if i != ''])
db = get_db()
if num_args > 1:
return ["usage: `hdfs dfs -ls path`"]
elif num_args == 0:
query = """SELECT f_type, f_permissions, u_id, grp_id, f_size,
last_edited, f_name FROM hdfs_file
WHERE
f_parent_id IS 1"""
children = db.execute(query).fetchall()
if len(children) > 0:
results = [f"Found {len(children)} items"]
results += [
f"{c[0]} {c[1]} {c[2]} {c[3]} {c[4]} {c[5]} {c[6]}"
for c in children
]
return results
else:
return [""]
id = _get_valid_file_path(args)
query = "SELECT f_type FROM hdfs_file WHERE id IS ?;"
result = db.execute(query, (id, )).fetchone()
if result is None:
return [""]
if result["f_type"] == "d":
query = """SELECT f_type, f_permissions, u_id, grp_id, f_size,
last_edited, f_name FROM hdfs_file
WHERE
f_parent_id IS ?"""
children = db.execute(query, (id, )).fetchall()
if len(children) > 0:
results = [f"Found {len(children)} items"]
results += [
f"{c[0]} {c[1]} {c[2]} {c[3]} {c[4]} {c[5]} {c[6]}"
for c in children
]
return results
else:
return [""]
elif result["f_type"] == "-":
query = """SELECT f_type, f_permissions, u_id, grp_id, f_size,
last_edited, f_name FROM hdfs_file
WHERE
id IS ?"""
file = db.execute(query, (id, )).fetchone()
results = [
f"""{file['f_type']} {file['f_permissions']}
{file['fu_id']} {file['grp_id']}, {file['f_size']}
{file['last_edited']} {file['f_name']}"""
]
return results
else:
return ["hdfs dfs -ls: invalid file type"]