port wikipedia importance functions to python

[nominatim.git] / nominatim / db / utils.py

diff --git a/nominatim/db/utils.py b/nominatim/db/utils.py
index abd72519fd0d9cbea758795f1bc49643cd8a8842..0490bbc869fe3f19a4bc87eac2fbed73d4b54d6f 100644 (file)
--- a/nominatim/db/utils.py
+++ b/nominatim/db/utils.py
@@ -1,12 +1,56 @@
 """
 Helper functions for handling DB accesses.
 """
+import subprocess
+import logging
+import gzip
 
-def execute_file(conn, fname):
-    """ Read an SQL file and run its contents against the given connection.
+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.
     """
-    with fname.open('r') as fdesc:
-        sql = fdesc.read()
-    with conn.cursor() as cur:
-        cur.execute(sql)
-    conn.commit()
+    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'))
+
+    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'))
+
+    proc.stdin.close()
+
+    ret = proc.wait()
+    if ret != 0 or remain > 0:
+        raise UsageError("Failed to execute SQL file.")