1 files changed, 53 insertions, 0 deletions
diff --git a/python/src/sa/mmap.pxi b/python/src/sa/mmap.pxi
new file mode 100644
index 00000000..6b65b779
--- /dev/null
+++ b/python/src/sa/mmap.pxi
@@ -0,0 +1,53 @@
+cimport posix.fcntl
+cimport posix.unistd
+from posix.unistd cimport off_t
+
+cdef extern from "sys/mman.h":
+    void *mmap(void *addr, size_t len, int prot, int flags, int fd, off_t offset)
+    int munmap(void *addr, size_t len)
+    enum:
+        PROT_READ
+    enum:
+        MAP_FILE
+        MAP_SHARED
+
+cdef extern from "sys/stat.h":
+    cdef struct stat:
+        off_t st_size
+    int fstat(int fildes, stat *buf)
+
+cdef class MemoryMap:
+    def __init__(self, filename):
+        self.fd = posix.fcntl.open(filename, posix.fcntl.O_RDONLY)
+        assert self.fd >= 0
+        # Get file size
+        cdef stat statbuf
+        fstat(self.fd, &statbuf) 
+        self.fs = statbuf.st_size
+        # Memory map file
+        self.map_start = mmap(NULL, self.fs, PROT_READ, MAP_FILE|MAP_SHARED, self.fd, 0)
+        self.map_ptr = self.map_start
+
+    def __dealloc__(self):
+        posix.unistd.close(self.fd)
+        munmap(self.map_start, self.fs)
+
+    cdef int read_int(self):
+        cdef int v = (<int*> self.map_ptr)[0]
+        self.map_ptr = &(<int*> self.map_ptr)[1]
+        return v
+
+    cdef int* read_int_array(self, int size):
+        cdef int* v = <int*> self.map_ptr
+        self.map_ptr = &(<int*> self.map_ptr)[size]
+        return v
+
+    cdef char* read_char_array(self, int size):
+        cdef char* v = <char*> self.map_ptr
+        self.map_ptr = &(<char*> self.map_ptr)[size]
+        return v
+
+    cdef float* read_float_array(self, int size):
+        cdef float* v = <float*> self.map_ptr
+        self.map_ptr = &(<float*> self.map_ptr)[size]
+        return v