1 files changed, 45 insertions, 0 deletions
diff --git a/figcode/awdb/file.py b/figcode/awdb/file.py
new file mode 100644
index 0000000..6d654f2
--- /dev/null
+++ b/figcode/awdb/file.py
@@ -0,0 +1,45 @@
+import os
+
+try:
+    from multiprocessing import Lock
+except ImportError:
+    from threading import Lock
+
+
+class FileBuffer(object):
+    def __init__(self, database):
+        self._handle = open(database, 'rb')
+        self._size = os.fstat(self._handle.fileno()).st_size
+        if not hasattr(os, 'pread'):
+            self._lock = Lock()
+
+    def __getitem__(self, key):
+        if isinstance(key, slice):
+            return self._read(key.stop - key.start, key.start)
+        if isinstance(key, int):
+            return self._read(1, key)[0]
+        raise TypeError("Invalid argument type.")
+
+    def rfind(self, needle, start):
+        pos = self._read(self._size - start - 1, start).rfind(needle)
+        if pos == -1:
+            return pos
+        return start + pos
+
+    def size(self):
+        return self._size
+
+    def close(self):
+        self._handle.close()
+
+    if hasattr(os, 'pread'):
+
+        def _read(self, buffersize, offset):
+            return os.pread(self._handle.fileno(), buffersize, offset)
+
+    else:
+
+        def _read(self, buffersize, offset):
+            with self._lock:
+                self._handle.seek(offset)
+                return self._handle.read(buffersize)