Use absolute_import from the __future__ everywhere

[bup.git] / lib / bup / hashsplit.py

diff --git a/lib/bup/hashsplit.py b/lib/bup/hashsplit.py
index cafbc983d145c28e37e14ed356091ccba2ebabe0..3cbcfc981b4e1280604712b2b0ffe2fbeff9411e 100644 (file)
--- a/lib/bup/hashsplit.py
+++ b/lib/bup/hashsplit.py
@@ -1,13 +1,11 @@
-import math, os
 
-from bup import _helpers
+from __future__ import absolute_import
+import io, math, os
 
-try:
-    _fmincore = _helpers.fmincore
-except AttributeError, e:
-    _fmincore = None
+from bup import _helpers, helpers
+from bup.helpers import sc_page_size
 
-_page_size = os.sysconf("SC_PAGE_SIZE")
+_fmincore = getattr(helpers, 'fmincore', None)
 
 BLOB_MAX = 8192*4   # 8192 is the "typical" blob size for bupsplit
 BLOB_READ_SIZE = 1024*1024
@@ -15,10 +13,9 @@ MAX_PER_TREE = 256
 progress_callback = None
 fanout = 16
 
-GIT_MODE_FILE = 0100644
-GIT_MODE_TREE = 040000
-GIT_MODE_SYMLINK = 0120000
-assert(GIT_MODE_TREE != 40000)  # 0xxx should be treated as octal
+GIT_MODE_FILE = 0o100644
+GIT_MODE_TREE = 0o40000
+GIT_MODE_SYMLINK = 0o120000
 
 # The purpose of this type of buffer is to avoid copying on peek(), get(),
 # and eat().  We do copy the buffer contents on put(), but that should
@@ -52,10 +49,12 @@ def _fadvise_pages_done(fd, first_page, count):
     assert(first_page >= 0)
     assert(count >= 0)
     if count > 0:
-        _helpers.fadvise_done(fd, first_page * _page_size, count * _page_size)
+        _helpers.fadvise_done(fd,
+                              first_page * sc_page_size,
+                              count * sc_page_size)
 
 
-def _nonresident_page_regions(status_bytes, max_region_len=None):
+def _nonresident_page_regions(status_bytes, incore_mask, max_region_len=None):
     """Return (start_page, count) pairs in ascending start_page order for
     each contiguous region of nonresident pages indicated by the
     mincore() status_bytes.  Limit the number of pages in each region
@@ -63,7 +62,7 @@ def _nonresident_page_regions(status_bytes, max_region_len=None):
     assert(max_region_len is None or max_region_len > 0)
     start = None
     for i, x in enumerate(status_bytes):
-        in_core = ord(x) & 1
+        in_core = x & incore_mask
         if start is None:
             if not in_core:
                 start = i
@@ -85,7 +84,7 @@ def _uncache_ours_upto(fd, offset, first_region, remaining_regions):
     (start_page, count) pair.  The final region must have a start_page
     of None."""
     rstart, rlen = first_region
-    while rstart is not None and (rstart + rlen) * _page_size <= offset:
+    while rstart is not None and (rstart + rlen) * sc_page_size <= offset:
         _fadvise_pages_done(fd, rstart, rlen)
         rstart, rlen = next(remaining_regions, (None, None))
     return (rstart, rlen)
@@ -97,10 +96,17 @@ def readfile_iter(files, progress=None):
         b = ''
         fd = rpr = rstart = rlen = None
         if _fmincore and hasattr(f, 'fileno'):
-            fd = f.fileno()
-            max_chunk = max(1, (8 * 1024 * 1024) / _page_size)
-            rpr = _nonresident_page_regions(_helpers.fmincore(fd), max_chunk)
-            rstart, rlen = next(rpr, (None, None))
+            try:
+                fd = f.fileno()
+            except io.UnsupportedOperation:
+                pass
+            if fd:
+                mcore = _fmincore(fd)
+                if mcore:
+                    max_chunk = max(1, (8 * 1024 * 1024) / sc_page_size)
+                    rpr = _nonresident_page_regions(mcore, helpers.MINCORE_INCORE,
+                                                    max_chunk)
+                    rstart, rlen = next(rpr, (None, None))
         while 1:
             if progress:
                 progress(filenum, len(b))