Files
Nominatim/nominatim/db/utils.py
Sarah Hoffmann b46adbad22 make sure psql always finishes
If an execption is raised by other means, we still have to close
the stdin pipe to psql to make sure that it exits and releases its
connection to the database.
2021-02-27 10:24:40 +01:00

60 lines
1.8 KiB
Python

"""
Helper functions for handling DB accesses.
"""
import subprocess
import logging
import gzip
from .connection import get_pg_env
from ..errors import UsageError
LOG = logging.getLogger()
def _pipe_to_proc(proc, fdesc):
chunk = fdesc.read(2048)
while chunk and proc.poll() is None:
try:
proc.stdin.write(chunk)
except BrokenPipeError as exc:
raise UsageError("Failed to execute SQL file.") from exc
chunk = fdesc.read(2048)
return len(chunk)
def execute_file(dsn, fname, ignore_errors=False, pre_code=None, post_code=None):
""" Read an SQL file and run its contents against the given database
using psql. Use `pre_code` and `post_code` to run extra commands
before or after executing the file. The commands are run within the
same session, so they may be used to wrap the file execution in a
transaction.
"""
cmd = ['psql']
if not ignore_errors:
cmd.extend(('-v', 'ON_ERROR_STOP=1'))
if not LOG.isEnabledFor(logging.INFO):
cmd.append('--quiet')
proc = subprocess.Popen(cmd, env=get_pg_env(dsn), stdin=subprocess.PIPE)
try:
if not LOG.isEnabledFor(logging.INFO):
proc.stdin.write('set client_min_messages to WARNING;'.encode('utf-8'))
if pre_code:
proc.stdin.write((pre_code + ';').encode('utf-8'))
if fname.suffix == '.gz':
with gzip.open(str(fname), 'rb') as fdesc:
remain = _pipe_to_proc(proc, fdesc)
else:
with fname.open('rb') as fdesc:
remain = _pipe_to_proc(proc, fdesc)
if remain == 0 and post_code:
proc.stdin.write((';' + post_code).encode('utf-8'))
finally:
proc.stdin.close()
ret = proc.wait()
if ret != 0 or remain > 0:
raise UsageError("Failed to execute SQL file.")