Make multi-processing optional for feed_dns

database.py

@@ -227,10 +227,19 @@ class Database(Profiler):
             self.log.warning("Allocating more than 512 MiB of RAM for "
                              "the Ip4 cache is not necessary.")
         max_cache_width = int(math.log2(max(1, max_size*8)))
+        allocated = False
         cache_width = min(2**32, max_cache_width)
+        while not allocated:
+            cache_size = 2**cache_width
+            try:
+                self.ip4cache = numpy.zeros(cache_size, dtype=numpy.bool)
+            except MemoryError:
+                self.log.exception(
+                    "Could not allocate cache. Retrying a smaller one.")
+                cache_width -= 1
+                continue
+            allocated = True
         self.ip4cache_shift = 32-cache_width
-        cache_size = 2**cache_width
-        self.ip4cache = numpy.zeros(cache_size, dtype=numpy.bool)
         for _ in self.exec_each_ip4(self._set_ip4cache):
             pass
 
@@ -288,11 +297,16 @@ class Database(Profiler):
         return True
 
     @staticmethod
-    def pack_ip4address(address: str) -> Ip4Path:
+    def pack_ip4address_low(address: str) -> int:
         addr = 0
         for split in address.split('.'):
-            addr = (addr << 8) + int(split)
+            octet = int(split)
-        return Ip4Path(addr, 32)
+            addr = (addr << 8) + octet
+        return addr
+
+    @staticmethod
+    def pack_ip4address(address: str) -> Ip4Path:
+        return Ip4Path(Database.pack_ip4address_low(address), 32)
 
     @staticmethod
     def unpack_ip4address(address: Ip4Path) -> str:
@@ -627,17 +641,17 @@ class Database(Profiler):
 
     def get_ip4(self, ip4_str: str) -> typing.Iterable[Path]:
         self.enter_step('get_ip4_pack')
-        ip4 = self.pack_ip4address(ip4_str)
+        ip4val = self.pack_ip4address_low(ip4_str)
         self.enter_step('get_ip4_cache')
-        if not self.ip4cache[ip4.value >> self.ip4cache_shift]:
+        if not self.ip4cache[ip4val >> self.ip4cache_shift]:
             return
         self.enter_step('get_ip4_brws')
         dic = self.ip4tree
-        for i in range(31, 31-ip4.prefixlen, -1):
+        for i in range(31, -1, -1):
-            bit = (ip4.value >> i) & 0b1
+            bit = (ip4val >> i) & 0b1
             if dic.active():
                 self.enter_step('get_ip4_yield')
-                yield Ip4Path(ip4.value >> (i+1) << (i+1), 31-i)
+                yield Ip4Path(ip4val >> (i+1) << (i+1), 31-i)
                 self.enter_step('get_ip4_brws')
             next_dic = dic.one if bit else dic.zero
             if next_dic is None:
@@ -645,7 +659,7 @@ class Database(Profiler):
             dic = next_dic
         if dic.active():
             self.enter_step('get_ip4_yield')
-            yield ip4
+            yield Ip4Path(ip4val, 32)
 
     def _unset_match(self,
                      match: Match,

feed_dns.py

@@ -29,20 +29,37 @@ FUNCTION_MAP: typing.Any = {
 
 class Writer(multiprocessing.Process):
     def __init__(self,
-                 recs_queue: multiprocessing.Queue,
+                 recs_queue: multiprocessing.Queue = None,
                  autosave_interval: int = 0,
                  ip4_cache: int = 0,
                  ):
-        super(Writer, self).__init__()
+        if recs_queue:  # MP
+            super(Writer, self).__init__()
+            self.recs_queue = recs_queue
         self.log = logging.getLogger(f'wr')
-        self.recs_queue = recs_queue
         self.autosave_interval = autosave_interval
         self.ip4_cache = ip4_cache
+        if not recs_queue:  # No MP
+            self.open_db()
 
-    def run(self) -> None:
+    def open_db(self) -> None:
         self.db = database.Database()
         self.db.log = logging.getLogger(f'wr')
         self.db.fill_ip4cache(max_size=self.ip4_cache)
+
+    def exec_record(self, record: Record) -> None:
+        self.db.enter_step('exec_record')
+        select, write, updated, name, value = record
+        try:
+            for source in select(self.db, value):
+                write(self.db, name, updated, source=source)
+        except (ValueError, IndexError):
+            # ValueError: non-number in IP
+            # IndexError: IP too big
+            self.log.exception("Cannot execute: %s", record)
+
+    def run(self) -> None:
+        self.open_db()
         if self.autosave_interval > 0:
             next_save = time.time() + self.autosave_interval
         else:
@@ -54,15 +71,7 @@ class Writer(multiprocessing.Process):
 
             record: Record
             for record in block:
-
+                self.exec_record(record)
-                select, write, updated, name, value = record
-                self.db.enter_step('feed_switch')
-
-                try:
-                    for source in select(self.db, value):
-                        write(self.db, name, updated, source=source)
-                except ValueError:
-                    self.log.exception("Cannot execute: %s", record)
 
             if next_save > 0 and time.time() > next_save:
                 self.log.info("Saving database...")
@@ -79,29 +88,37 @@ class Writer(multiprocessing.Process):
 class Parser():
     def __init__(self,
                  buf: typing.Any,
-                 recs_queue: multiprocessing.Queue,
+                 recs_queue: multiprocessing.Queue = None,
-                 block_size: int,
+                 block_size: int = 0,
+                 writer: Writer = None,
                  ):
-        super(Parser, self).__init__()
+        assert bool(writer) ^ bool(block_size and recs_queue)
         self.buf = buf
         self.log = logging.getLogger('pr')
         self.recs_queue = recs_queue
-        self.block: typing.List[Record] = list()
+        if writer:  # No MP
-        self.block_size = block_size
+            self.prof: database.Profiler = writer.db
-        self.prof = database.Profiler()
+            self.register = writer.exec_record
-        self.prof.log = logging.getLogger('pr')
+        else:  # MP
+            self.block: typing.List[Record] = list()
+            self.block_size = block_size
+            self.prof = database.Profiler()
+            self.prof.log = logging.getLogger('pr')
+            self.register = self.add_to_queue
 
-    def register(self, record: Record) -> None:
+    def add_to_queue(self, record: Record) -> None:
         self.prof.enter_step('register')
         self.block.append(record)
         if len(self.block) >= self.block_size:
             self.prof.enter_step('put_block')
+            assert self.recs_queue
             self.recs_queue.put(self.block)
             self.block = list()
 
     def run(self) -> None:
         self.consume()
-        self.recs_queue.put(self.block)
+        if self.recs_queue:
+            self.recs_queue.put(self.block)
         self.prof.profile()
 
     def consume(self) -> None:
@@ -203,6 +220,10 @@ if __name__ == '__main__':
         '-a', '--autosave-interval', type=int, default=900,
         help="Interval to which the database will save in seconds. "
         "0 to disable.")
+    args_parser.add_argument(
+        '-s', '--single-process', action='store_true',
+        help="Only use one process. "
+        "Might be useful for single core computers.")
     args_parser.add_argument(
         '-4', '--ip4-cache', type=int, default=0,
         help="RAM cache for faster IPv4 lookup. "
@@ -211,17 +232,29 @@ if __name__ == '__main__':
         "be a memory-heavy process, even without the cache.")
     args = args_parser.parse_args()
 
-    recs_queue: multiprocessing.Queue = multiprocessing.Queue(
+    parser_cls = PARSERS[args.parser]
-        maxsize=args.queue_size)
+    if args.single_process:
+        writer = Writer(
+            autosave_interval=args.autosave_interval,
+            ip4_cache=args.ip4_cache
+        )
+        parser = parser_cls(args.input, writer=writer)
+        parser.run()
+    else:
+        recs_queue: multiprocessing.Queue = multiprocessing.Queue(
+            maxsize=args.queue_size)
 
-    writer = Writer(recs_queue,
+        writer = Writer(recs_queue,
-                    autosave_interval=args.autosave_interval,
+                        autosave_interval=args.autosave_interval,
-                    ip4_cache=args.ip4_cache
+                        ip4_cache=args.ip4_cache
-                    )
+                        )
-    writer.start()
+        writer.start()
 
-    parser = PARSERS[args.parser](args.input, recs_queue, args.block_size)
+        parser = parser_cls(args.input,
-    parser.run()
+                            recs_queue=recs_queue,
+                            block_size=args.block_size
+                            )
+        parser.run()
 
-    recs_queue.put(None)
+        recs_queue.put(None)
-    writer.join()
+        writer.join()