X-Git-Url: https://git.saurik.com/apple/system_cmds.git/blobdiff_plain/1a7e3f61d38d679bba59130891c2031b5a0092b6..bd6521f0fc816ab056bc71376f9706a69b3b52c1:/CPPUtil/UtilMappedFile.cpp

diff --git a/CPPUtil/UtilMappedFile.cpp b/CPPUtil/UtilMappedFile.cpp
new file mode 100644
index 0000000..acc71bd
--- /dev/null
+++ b/CPPUtil/UtilMappedFile.cpp
@@ -0,0 +1,57 @@
+//
+//  UtilMappedFile.cpp
+//  CPPUtil
+//
+//  Created by James McIlree on 4/19/13.
+//  Copyright (c) 2013 Apple. All rights reserved.
+//
+
+#include "CPPUtil.h"
+
+#include <sys/mman.h>
+
+BEGIN_UTIL_NAMESPACE
+
+static int open_fd(const char* path, size_t& file_size)
+{
+	int fd = open(path, O_RDONLY, 0);
+	if(fd >= 0) {
+		struct stat data;
+		if (fstat(fd, &data) == 0) {
+			if (S_ISREG(data.st_mode)) {
+				// Is it zero sized?
+				if (data.st_size > 0) {
+					file_size = (size_t)data.st_size;
+					return fd;
+				}
+			}
+		}
+		close(fd);
+	}
+
+	return -1;
+}
+
+MappedFile::MappedFile(const char* path) :
+	_address(NULL),
+	_size(0)
+{
+        ASSERT(path, "Sanity");
+	int fd = open_fd(path, _size);
+	if (fd >= 0) {
+		_address = (unsigned char*)mmap(NULL, _size, PROT_READ, MAP_FILE | MAP_SHARED, fd, 0);
+		if (_address == (void*)-1) {
+			_address = NULL;
+		}
+		close(fd);
+	}
+}
+
+MappedFile::~MappedFile()
+{
+	if (_address != NULL) {
+		munmap(_address, _size);
+	}
+}
+
+END_UTIL_NAMESPACE