]> git.openstreetmap.org Git - nominatim.git/blobdiff - nominatim/db/utils.py
Merge pull request #2629 from tareqpi/country-names-yaml-configuration
[nominatim.git] / nominatim / db / utils.py
index 575f301082e044e2d04a3a31fbcc69c8dfd2f8ac..87b0545fc5ecba66a956219cfbf247e633c16eaf 100644 (file)
@@ -1,12 +1,19 @@
+# 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.
 """
 import subprocess
 import logging
 import gzip
 """
 Helper functions for handling DB accesses.
 """
 import subprocess
 import logging
 import gzip
+import io
 
 
-from .connection import get_pg_env
-from ..errors import UsageError
+from nominatim.db.connection import get_pg_env
+from nominatim.errors import UsageError
 
 LOG = logging.getLogger()
 
 
 LOG = logging.getLogger()
 
@@ -21,27 +28,86 @@ def _pipe_to_proc(proc, fdesc):
 
     return len(chunk)
 
 
     return len(chunk)
 
-def execute_file(dsn, fname, ignore_errors=False):
+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
     """ 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'))
     """
     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)
 
     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'))
+    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 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()
     if ret != 0 or remain > 0:
         raise UsageError("Failed to execute SQL file.")
     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(u'\\'): u'\\\\',
+                    ord(u'\t'): u'\\t',
+                    ord(u'\n'): u'\\n'}
+
+
+class CopyBuffer:
+    """ Data collector for the copy_from command.
+    """
+
+    def __init__(self):
+        self.buffer = io.StringIO()
+
+
+    def __enter__(self):
+        return self
+
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        if self.buffer is not None:
+            self.buffer.close()
+
+
+    def add(self, *data):
+        """ 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, table, columns=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)