new branch to integrate BlockDevice, BlockCache

git-svn-id: https://profuse.googlecode.com/svn/branches/profuse_interim@331 aa027e90-d47c-11dd-86d7-074df07e0730
2026-03-13 08:41:50 +00:00 · 2011-02-19 18:05:57 +00:00
parent e5f935e435
commit 14e9b43f32
6 changed files with 748 additions and 0 deletions
--- a/Cache/MappedBlockCache.cpp
+++ b/Cache/MappedBlockCache.cpp
@@ -0,0 +1,134 @@
+
+#include <algorithm>
+#include <cerrno>
+#include <cstring>
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <Cache/MappedBlockCache.h>
+#include <Device/BlockDevice.h>
+
+#include <ProFUSE/Exception.h>
+
+
+
+using namespace Device;
+
+using ProFUSE::Exception;
+using ProFUSE::POSIXException;
+
+
+MappedBlockCache::MappedBlockCache(BlockDevice *device, void *data) :
+    BlockCache(device)
+{
+    _data = (uint8_t *)data;
+    _dirty = false;
+}
+
+MappedBlockCache::~MappedBlockCache()
+{
+  if (_dirty) sync();
+}
+
+
+void *MappedBlockCache::acquire(unsigned block)
+{
+#undef __METHOD__
+#define __METHOD__ "MappedBlockCache::load"
+    
+    if (block >= blocks())
+        throw Exception(__METHOD__ ": Invalid block.");
+        
+    
+    return _data + block * 512;
+}
+
+void MappedBlockCache::release(unsigned block, int flags)
+{
+#undef __METHOD__
+#define __METHOD__ "MappedBlockCache::unload"
+
+    // kBlockCommitNow implies kBlockDirty. 
+    if (flags & kBlockCommitNow)
+    {
+        sync(block);
+        return;
+    }
+
+    if (flags & kBlockDirty) _dirty = true;
+}
+
+
+
+void MappedBlockCache::write(unsigned block, const void *vp)
+{
+#undef __METHOD__
+#define __METHOD__ "MappedBlockCache::write"
+    
+    if (block >= blocks())
+        throw Exception(__METHOD__ ": Invalid block.");
+    
+    _dirty = true;
+    std::memcpy(_data + block * 512, vp, 512);
+}
+
+
+void MappedBlockCache::zeroBlock(unsigned block)
+{
+#undef __METHOD__
+#define __METHOD__ "MappedBlockCache::zeroBlock"
+    
+    if (block >= blocks())
+        throw Exception(__METHOD__ ": Invalid block.");
+    
+    
+    _dirty = true;
+    std::memset(_data + block * 512, 0, 512);
+}
+
+
+
+// sync everything.
+void MappedBlockCache::sync()
+{
+  _device->sync();
+  _dirty = false;
+}
+
+/*
+ *
+ * sync an individual page.
+ *
+ */
+void MappedBlockCache::sync(unsigned block)
+{
+#undef __METHOD__
+#define __METHOD__ "MappedBlockCache::sync"
+
+
+    int pagesize = ::getpagesize();
+        
+    void *start = _data + block * 512;
+    void *end = _data + 512 + block * 512;
+
+
+    start = (void *)((ptrdiff_t)start / pagesize * pagesize);
+    end = (void *)((ptrdiff_t)end / pagesize * pagesize);
+
+    if (::msync(start, pagesize, MS_SYNC) != 0)
+        throw POSIXException(__METHOD__ ": msync", errno);
+    
+    if (start != end)
+    {
+        if (::msync(end, pagesize, MS_SYNC) != 0)
+            throw POSIXException(__METHOD__ ": msync", errno);    
+    }
+}
+
+void MappedBlockCache::markDirty(unsigned block)
+{
+    _dirty = true;
+}
+