win32: Add routines to abstract memory-mapped file functions

In particular, the git__mmap() and git__munmap() routines provide
the interface to platform specific memory-mapped file facilities.
We provide implementations for unix and win32, which can be found
in their own sub-directories.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/map.h b/src/map.h
new file mode 100644
index 000000000..3188ffdbb
--- /dev/null
+++ b/src/map.h
@@ -0,0 +1,31 @@
+#ifndef INCLUDE_map_h__
+#define INCLUDE_map_h__
+
+#include "common.h"
+
+
+/* git__mmap() prot values */
+#define GIT_PROT_NONE  0x0
+#define GIT_PROT_READ  0x1
+#define GIT_PROT_WRITE 0x2
+#define GIT_PROT_EXEC  0x4
+
+/* git__mmmap() flags values */
+#define GIT_MAP_FILE    0
+#define GIT_MAP_SHARED  1
+#define GIT_MAP_PRIVATE 2
+#define GIT_MAP_TYPE    0xf
+#define GIT_MAP_FIXED   0x10
+
+typedef struct {  /* memory mapped buffer   */
+	void *data;  /* data bytes          */
+	size_t len;  /* data length         */
+#ifdef GIT_WIN32
+	HANDLE fmh;  /* file mapping handle */
+#endif
+} git_map;
+
+extern int git__mmap(git_map *out, size_t len, int prot, int flags, int fd, off_t offset);
+extern int git__munmap(git_map *map);
+
+#endif /* INCLUDE_map_h__ */