add support for OpenAsSecondary and TryCatchUpWithPrimary

rocksdb/_rocksdb.pyx

@@ -1722,8 +1722,9 @@ cdef class DB(object):
     cdef db.DB* db
     cdef list cf_handles
     cdef list cf_options
+    cdef py_bool is_secondary
 
-    def __cinit__(self, db_name, Options opts, dict column_families=None, read_only=False):
+    def __cinit__(self, db_name, Options opts, dict column_families=None, read_only=False, secondary_name=''):
         cdef Status st
         cdef string db_path
         cdef vector[db.ColumnFamilyDescriptor] column_family_descriptors
@@ -1738,6 +1739,7 @@ cdef class DB(object):
             raise Exception("Options object is already used by another DB")
 
         db_path = path_to_string(db_name)
+
         if not column_families or default_cf_name not in column_families:
             # Always add the default column family
             column_family_descriptors.push_back(
@@ -1771,7 +1773,19 @@ cdef class DB(object):
                     )
                 )
                 self.cf_options.append(cf_options)
-        if read_only:
+
+        if secondary_name != '':
+            secondary_path = path_to_string(secondary_name)
+            self.is_secondary = True
+            with nogil:
+                st = db.DB_OpenAsSecondary_ColumnFamilies(
+                    deref(opts.opts),
+                    db_path,
+                    secondary_path,
+                    column_family_descriptors,
+                    &column_family_handles,
+                    &self.db)
+        elif read_only:
             with nogil:
                 st = db.DB_OpenForReadOnly_ColumnFamilies(
                     deref(opts.opts),
@@ -1847,6 +1861,11 @@ cdef class DB(object):
                 self.db.Close()
                 self.db = NULL
 
+    def try_catch_up_with_primary(self):
+        with nogil:
+            st = self.db.TryCatchUpWithPrimary()
+        check_status(st)
+
     def __dealloc__(self):
         self.close()
 

rocksdb/db.pxd

@@ -170,6 +170,7 @@ cdef extern from "rocksdb/db.h" namespace "rocksdb":
         Status DisableFileDeletions() nogil except+
         Status EnableFileDeletions() nogil except+
         Status Close() nogil except+
+        Status TryCatchUpWithPrimary() nogil except+
 
         # TODO: Status GetSortedWalFiles(VectorLogPtr& files)
         # TODO: SequenceNumber GetLatestSequenceNumber()
@@ -209,6 +210,20 @@ cdef extern from "rocksdb/db.h" namespace "rocksdb":
         DB**,
         cpp_bool) nogil except+
 
+    cdef Status DB_OpenAsSecondary "rocksdb::DB::OpenAsSecondary"(
+        const options.Options&,
+        const string&,
+        const string&,
+        DB**) nogil except+
+
+    cdef Status DB_OpenAsSecondary_ColumnFamilies "rocksdb::DB::OpenAsSecondary"(
+        const options.Options&,
+        const string&,
+        const string&,
+        const vector[ColumnFamilyDescriptor]&,
+        vector[ColumnFamilyHandle*]*,
+        DB**) nogil except+
+
     cdef Status RepairDB(const string& dbname, const options.Options&)
 
     cdef Status ListColumnFamilies "rocksdb::DB::ListColumnFamilies" (

rocksdb/tests/test_db.py

@@ -53,6 +53,23 @@ class TestDB(TestHelper):
         self.db.put(b"a", b"b")
         self.assertEqual(b"b", self.db.get(b"a"))
 
+    def test_put_then_get_from_secondary(self):
+        secondary_location = os.path.join(self.db_loc, "secondary")
+        secondary = rocksdb.DB(
+            os.path.join(self.db_loc, "test"),
+            rocksdb.Options(create_if_missing=True, max_open_files=-1),
+            secondary_name=secondary_location
+        )
+        self.addCleanup(secondary.close)
+
+        self.assertIsNone(secondary.get(b"a"))
+        self.db.put(b"a", b"b")
+        self.assertEqual(b"b", self.db.get(b"a"))
+        self.assertIsNone(secondary.get(b"a"))
+        secondary.try_catch_up_with_primary()
+        self.assertEqual(b"b", secondary.get(b"a"))
+
+
     def test_multi_get(self):
         self.db.put(b"a", b"1")
         self.db.put(b"b", b"2")