# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1495810345 -7200
# Node ID 3c756db2eb7e32a6503bb959d8e8cb9671b6f98f
# Parent  779e632b6e6982d2349e29e97f349283de18f63e
Support direct copying of record data when inserting periods into PostgreSQL.

diff -r 779e632b6e69 -r 3c756db2eb7e imiptools/freebusy.py
--- a/imiptools/freebusy.py	Wed May 24 15:41:14 2017 +0200
+++ b/imiptools/freebusy.py	Fri May 26 16:52:25 2017 +0200
@@ -24,18 +24,62 @@
 from imiptools.period import get_overlapping, Period, PeriodBase
 from imiptools.sql import DatabaseOperations
 
+try:
+    from cStringIO import StringIO
+except ImportError:
+    from StringIO import StringIO
+
 def from_string(s, encoding):
+
+    "Interpret 's' using 'encoding', preserving None."
+
     if s:
         return unicode(s, encoding)
     else:
         return s
 
 def to_string(s, encoding):
+
+    "Encode 's' using 'encoding', preserving None."
+
     if s:
         return s.encode(encoding)
     else:
         return s
 
+def to_copy_string(s, encoding):
+
+    """
+    Encode 's' using 'encoding' as a string suitable for use in tabular data
+    acceptable to the PostgreSQL COPY command with \N as null.
+    """
+
+    s = to_string(s, encoding)
+    return s is None and "\\N" or s
+
+def to_copy_file(records):
+
+    """
+    Encode the given 'records' and store them in a file-like object for use with
+    a tabular import mechanism. Return the file-like object.
+    """
+
+    io = StringIO()
+    for values in records:
+        l = []
+        for v in values:
+            l.append(to_copy_string(v, "utf-8"))
+        io.write("\t".join(l))
+        io.write("\n")
+    io.seek(0)
+    return io
+
+def quote_column(column):
+
+    "Quote 'column' using the SQL keyword quoting notation."
+
+    return '"%s"' % column
+
 class FreeBusyPeriod(PeriodBase):
 
     "A free/busy record abstraction."
@@ -265,8 +309,7 @@
     # List emulation methods.
 
     def __iadd__(self, periods):
-        for period in periods:
-            self.insert_period(period)
+        self.insert_periods(periods)
         return self
 
     def append(self, period):
@@ -274,6 +317,13 @@
 
     # Operations.
 
+    def insert_periods(self, periods):
+
+        "Insert the given 'periods' into the collection."
+
+        for p in periods:
+            self.insert_period(p)
+
     def can_schedule(self, periods, uid, recurrenceid):
 
         """
@@ -409,8 +459,7 @@
 
         self.remove_specific_event_periods(uid, recurrenceid)
 
-        for p in periods:
-            self.insert_period(p)
+        self.insert_periods(periods)
 
     def update_freebusy(self, periods, transp, uid, recurrenceid, summary, organiser):
 
@@ -446,8 +495,7 @@
 
         self.remove_specific_event_periods(uid, recurrenceid, attendee)
 
-        for p in periods:
-            self.insert_period(p)
+        self.insert_periods(periods)
 
     def update_freebusy(self, periods, transp, uid, recurrenceid, summary, organiser, attendee=None):
 
@@ -790,6 +838,27 @@
 
         self.cursor.execute(query, values)
 
+    def insert_periods(self, periods):
+
+        "Insert the given 'periods' into the collection."
+
+        if not hasattr(self.cursor, "copy_from"):
+            return FreeBusyCollectionBase.insert_periods(self, periods)
+
+        self._check_mutable()
+
+        columns = self.merge_default_columns(self.period_columns)
+
+        all_values = []
+        for period in periods:
+            all_values.append(self.merge_default_values(period.as_tuple(string_datetimes=True)))
+
+        f = to_copy_file(all_values)
+
+        # Copy from the file-like object to the table.
+
+        self.cursor.copy_from(f, self.table_name, columns=map(quote_column, columns))
+
     def remove_periods(self, periods):
 
         "Remove the given 'periods' from the collection."