1 files changed, 77 insertions, 0 deletions
diff --git a/src/core/SkMMapStream.cpp b/src/core/SkMMapStream.cpp
new file mode 100644
index 0000000000..7388e81498
--- /dev/null
+++ b/src/core/SkMMapStream.cpp
@@ -0,0 +1,77 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SkMMapStream.h"
+
+#include <unistd.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <errno.h>
+
+SkMMAPStream::SkMMAPStream(const char filename[])
+{
+    fAddr = NULL;   // initialize to failure case
+    fSize = 0;
+
+    int fildes = open(filename, O_RDONLY);
+    if (fildes < 0)
+    {
+        SkDEBUGF(("---- failed to open(%s) for mmap stream error=%d\n", filename, errno));
+        return;
+    }
+
+    off_t offset = lseek(fildes, 0, SEEK_END);    // find the file size
+    if (offset == -1)
+    {
+        SkDEBUGF(("---- failed to lseek(%s) for mmap stream error=%d\n", filename, errno));
+        close(fildes);
+        return;
+    }
+    (void)lseek(fildes, 0, SEEK_SET);   // restore file offset to beginning
+
+    // to avoid a 64bit->32bit warning, I explicitly create a size_t size
+    size_t size = static_cast<size_t>(offset);
+
+    void* addr = mmap(NULL, size, PROT_READ, MAP_SHARED, fildes, 0);
+
+    // According to the POSIX documentation of mmap it adds an extra reference
+    // to the file associated with the fildes which is not removed by a
+    // subsequent close() on that fildes. This reference is removed when there
+    // are no more mappings to the file.
+    close(fildes);
+
+    if (MAP_FAILED == addr)
+    {
+        SkDEBUGF(("---- failed to mmap(%s) for mmap stream error=%d\n", filename, errno));
+        return;
+    }
+
+    this->INHERITED::setMemory(addr, size);
+
+    fAddr = addr;
+    fSize = size;
+}
+
+SkMMAPStream::~SkMMAPStream()
+{
+    this->closeMMap();
+}
+
+void SkMMAPStream::setMemory(const void* data, size_t length, bool copyData)
+{
+    this->closeMMap();
+    this->INHERITED::setMemory(data, length, copyData);
+}
+
+void SkMMAPStream::closeMMap()
+{
+    if (fAddr)
+    {
+        munmap(fAddr, fSize);
+        fAddr = NULL;
+    }
+}