1 files changed, 50 insertions, 0 deletions
diff --git a/compat/mmap.c b/compat/mmap.c
new file mode 100644
index 0000000..a051c47
--- /dev/null
+++ b/compat/mmap.c
@@ -0,0 +1,50 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include "../cache.h"
+
+void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset)
+{
+	int n = 0;
+
+	if (start != NULL || !(flags & MAP_PRIVATE))
+		die("Invalid usage of gitfakemmap.");
+
+	if (lseek(fd, offset, SEEK_SET) < 0) {
+		errno = EINVAL;
+		return MAP_FAILED;
+	}
+
+	start = xmalloc(length);
+	if (start == NULL) {
+		errno = ENOMEM;
+		return MAP_FAILED;
+	}
+
+	while (n < length) {
+		int count = read(fd, start+n, length-n);
+
+		if (count == 0) {
+			memset(start+n, 0, length-n);
+			break;
+		}
+
+		if (count < 0) {
+			free(start);
+			errno = EACCES;
+			return MAP_FAILED;
+		}
+
+		n += count;
+	}
+
+	return start;
+}
+
+int gitfakemunmap(void *start, size_t length)
+{
+	free(start);
+	return 0;
+}
+