+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
"""
Helper functions for handling DB accesses.
"""
+from typing import IO, Optional, Union, Any, Iterable
import subprocess
import logging
+import gzip
+import io
+from pathlib import Path
-from .connection import get_pg_env
-from ..errors import UsageError
+from nominatim.db.connection import get_pg_env, Cursor
+from nominatim.errors import UsageError
LOG = logging.getLogger()
-def execute_file(dsn, fname, ignore_errors=False):
+def _pipe_to_proc(proc: 'subprocess.Popen[bytes]',
+ fdesc: Union[IO[bytes], gzip.GzipFile]) -> int:
+ assert proc.stdin is not None
+ 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: str, fname: Path,
+ ignore_errors: bool = False,
+ pre_code: Optional[str] = None,
+ post_code: Optional[str] = None) -> None:
""" Read an SQL file and run its contents against the given database
- using psql.
+ 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'))
- proc = subprocess.Popen(cmd, env=get_pg_env(dsn), stdin=subprocess.PIPE)
-
if not LOG.isEnabledFor(logging.INFO):
- proc.stdin.write('set client_min_messages to WARNING;'.encode('utf-8'))
+ cmd.append('--quiet')
- with fname.open('rb') as fdesc:
- chunk = fdesc.read(2048)
- while chunk and proc.poll() is None:
- proc.stdin.write(chunk)
- chunk = fdesc.read(2048)
+ with subprocess.Popen(cmd, env=get_pg_env(dsn), stdin=subprocess.PIPE) as proc:
+ assert proc.stdin is not None
+ 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)
- proc.stdin.close()
+ if remain == 0 and post_code:
+ proc.stdin.write((';' + post_code).encode('utf-8'))
+ finally:
+ proc.stdin.close()
+ ret = proc.wait()
- ret = proc.wait()
- print(ret, chunk)
- if ret != 0 or chunk:
+ if ret != 0 or remain > 0:
raise UsageError("Failed to execute SQL file.")
+
+
+# List of characters that need to be quoted for the copy command.
+_SQL_TRANSLATION = {ord('\\'): '\\\\',
+ ord('\t'): '\\t',
+ ord('\n'): '\\n'}
+
+
+class CopyBuffer:
+ """ Data collector for the copy_from command.
+ """
+
+ def __init__(self) -> None:
+ self.buffer = io.StringIO()
+
+
+ def __enter__(self) -> 'CopyBuffer':
+ return self
+
+
+ def __exit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> None:
+ if self.buffer is not None:
+ self.buffer.close()
+
+
+ def add(self, *data: Any) -> None:
+ """ Add another row of data to the copy buffer.
+ """
+ first = True
+ for column in data:
+ if first:
+ first = False
+ else:
+ self.buffer.write('\t')
+ if column is None:
+ self.buffer.write('\\N')
+ else:
+ self.buffer.write(str(column).translate(_SQL_TRANSLATION))
+ self.buffer.write('\n')
+
+
+ def copy_out(self, cur: Cursor, table: str, columns: Optional[Iterable[str]] = None) -> None:
+ """ Copy all collected data into the given table.
+ """
+ if self.buffer.tell() > 0:
+ self.buffer.seek(0)
+ cur.copy_from(self.buffer, table, columns=columns)
projects / nominatim.git / blobdiff