.

wcfs/internal/mm.pyx

@@ -79,6 +79,8 @@ def lock(const unsigned char[::1] mem not None, int flags):
     if err:
         PyErr_SetFromErrno(OSError)
 
+    return  # ok
+
 
 # unlock unlocks mem pages from being pinned in RAM.
 def unlock(const unsigned char[::1] mem not None):
@@ -89,6 +91,8 @@ def unlock(const unsigned char[::1] mem not None):
     if err:
         PyErr_SetFromErrno(OSError)
 
+    return  # ok
+
 
 from posix.types cimport off_t
 
@@ -102,6 +106,16 @@ def map_ro(int fd, off_t offset, size_t size):
 
     return <unsigned char[:size:1]>addr
 
+# map_into mmaps fd[offset:...] into mem's memory.
+def map_into_ro(unsigned char[::1] mem not None, int fd, off_t offset):
+    cdef void   *addr = &mem[0]
+    cdef size_t size  = mem.shape[0]
+
+    addr = mman.mmap(addr, size, mman.PROT_READ, mman.MAP_SHARED | mman.MAP_FIXED, fd, offset)
+    if addr == mman.MAP_FAILED:
+        PyErr_SetFromErrno(OSError)
+
+    return  # ok
 
 # unmap unmaps memory covered by mem.
 def unmap(const unsigned char[::1] mem not None):
@@ -111,7 +125,8 @@ def unmap(const unsigned char[::1] mem not None):
     cdef err = mman.munmap(<void *>addr, size)
     if err:
         PyErr_SetFromErrno(OSError)
-    # ok
+
+    return  # ok
 
 
 # advise advises kernel about use of mem's memory.
@@ -125,3 +140,5 @@ def advise(const unsigned char[::1] mem not None, int advice):
     cdef err = mman.posix_madvise(<void *>addr, size, advice)
     if err:
         PyErr_SetFromErrno(OSError)
+
+    return  # ok