Imported Upstream version 1.5.1

cpp/src/libxtreemfs/stripe_translator.cpp

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2009-2011 by Patrick Schaefer, Zuse Institute Berlin
+ *
+ * Licensed under the BSD License, see LICENSE file for details.
+ *
+ */
+#include "libxtreemfs/stripe_translator.h"
+
+#include <algorithm>
+#include <vector>
+
+using namespace std;
+using namespace xtreemfs::pbrpc;
+
+namespace xtreemfs {
+
+void StripeTranslatorRaid0::TranslateWriteRequest(
+    const char *buf,
+    size_t size,
+    int64_t offset,
+    PolicyContainer policies,
+    std::vector<WriteOperation>* operations) const {
+  // stripe size is stored in kB
+  unsigned int stripe_size = (*policies.begin())->stripe_size() * 1024;
+
+  size_t start = 0;
+  while (start < size) {
+    size_t obj_number = static_cast<size_t>(start + offset) / stripe_size;
+    size_t req_offset = (start + offset) % stripe_size;
+    size_t req_size
+      = min(size - start, static_cast<size_t>(stripe_size - req_offset));
+
+    std::vector<size_t> osd_offsets;
+    for (PolicyContainer::iterator i = policies.begin();
+         i != policies.end();
+         ++i) {
+      osd_offsets.push_back(obj_number % (*i)->width());
+    }
+
+    operations->push_back(WriteOperation(
+        obj_number, osd_offsets, req_size, req_offset, buf + start));
+
+    start += req_size;
+  }
+}
+
+void StripeTranslatorRaid0::TranslateReadRequest(
+    char *buf,
+    size_t size,
+    int64_t offset,
+    PolicyContainer policies,
+    std::vector<ReadOperation>* operations) const {
+  // stripe size is stored in kB
+  unsigned int stripe_size = (*policies.begin())->stripe_size() * 1024;
+
+  size_t start = 0;
+  while (start < size) {
+    size_t obj_number = static_cast<size_t>(start + offset) / stripe_size;
+    size_t req_offset = (start + offset) % stripe_size;
+    size_t req_size
+      = min(size - start, static_cast<size_t>(stripe_size - req_offset));
+
+    std::vector<size_t> osd_offsets;
+    for (PolicyContainer::iterator i = policies.begin();
+         i != policies.end();
+         ++i) {
+      osd_offsets.push_back(obj_number % (*i)->width());
+    }
+
+    operations->push_back(ReadOperation(
+        obj_number, osd_offsets, req_size, req_offset, buf + start));
+
+    start += req_size;
+  }
+}
+
+}  // namespace xtreemfs