osdc/Striper: implemented a lightweight version of StripedReadResult

Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/src/osdc/Striper.cc b/src/osdc/Striper.cc
index 005a4637dc1ef332fadb565ef310d979710c8295..5c5b4cb7d72e90d93cc15fb85fc1e2e526a761da 100644 (file)
--- a/src/osdc/Striper.cc
+++ b/src/osdc/Striper.cc
@@ -313,6 +313,25 @@ void Striper::StripedReadResult::add_partial_result(
   }
 }
 
+void Striper::StripedReadResult::add_partial_result(
+  CephContext *cct, bufferlist&& bl,
+  const striper::LightweightBufferExtents& buffer_extents)
+{
+  ldout(cct, 10) << "add_partial_result(" << this << ") " << bl.length()
+                << " to " << buffer_extents << dendl;
+  for (auto& be : buffer_extents) {
+    auto& r = partial[be.first];
+    size_t actual = std::min<uint64_t>(bl.length(), be.second);
+    if (buffer_extents.size() == 1) {
+      r.first = std::move(bl);
+    } else {
+      bl.splice(0, actual, &r.first);
+    }
+    r.second = be.second;
+    total_intended_len += r.second;
+  }
+}
+
 void Striper::StripedReadResult::add_partial_sparse_result(
   CephContext *cct, bufferlist& bl, const map<uint64_t, uint64_t>& bl_map,
   uint64_t bl_off, const std::vector<pair<uint64_t,uint64_t> >& buffer_extents)
@@ -321,66 +340,88 @@ void Striper::StripedReadResult::add_partial_sparse_result(
                 << " covering " << bl_map << " (offset " << bl_off << ")"
                 << " to " << buffer_extents << dendl;
   auto s = bl_map.cbegin();
-  for (auto p = buffer_extents.cbegin(); p != buffer_extents.cend(); ++p) {
-    uint64_t tofs = p->first;
-    size_t tlen = p->second;
-    ldout(cct, 30) << " be " << tofs << "~" << tlen << dendl;
-    while (tlen > 0) {
-      ldout(cct, 20) << "  t " << tofs << "~" << tlen
-                    << " bl has " << bl.length()
-                    << " off " << bl_off
-                    << dendl;
-      if (s == bl_map.end()) {
-       ldout(cct, 20) << "  s at end" << dendl;
-       auto& r = partial[tofs];
-       r.second = tlen;
-       total_intended_len += r.second;
-       break;
-      }
+  for (auto& be : buffer_extents) {
+    add_partial_sparse_result(cct, bl, &s, bl_map.end(), &bl_off, be.first,
+                              be.second);
+  }
+}
 
-      ldout(cct, 30) << "  s " << s->first << "~" << s->second << dendl;
+void Striper::StripedReadResult::add_partial_sparse_result(
+    CephContext *cct, ceph::buffer::list& bl,
+    const std::map<uint64_t, uint64_t>& bl_map, uint64_t bl_off,
+    const striper::LightweightBufferExtents& buffer_extents) {
+  ldout(cct, 10) << "add_partial_sparse_result(" << this << ") " << bl.length()
+                << " covering " << bl_map << " (offset " << bl_off << ")"
+                << " to " << buffer_extents << dendl;
+  auto s = bl_map.cbegin();
+  for (auto& be : buffer_extents) {
+    add_partial_sparse_result(cct, bl, &s, bl_map.cend(), &bl_off, be.first,
+                              be.second);
+  }
+}
 
-      // skip zero-length extent
-      if (s->second == 0) {
-       ldout(cct, 30) << "  s len 0, skipping" << dendl;
-       ++s;
-       continue;
-      }
+void Striper::StripedReadResult::add_partial_sparse_result(
+    CephContext *cct, bufferlist& bl,
+    std::map<uint64_t, uint64_t>::const_iterator* it,
+    const std::map<uint64_t, uint64_t>::const_iterator& end_it,
+    uint64_t* bl_off, uint64_t tofs, uint64_t tlen) {
+  ldout(cct, 30) << " be " << tofs << "~" << tlen << dendl;
+
+  auto& s = *it;
+  while (tlen > 0) {
+    ldout(cct, 20) << "  t " << tofs << "~" << tlen
+                   << " bl has " << bl.length()
+                   << " off " << *bl_off << dendl;
+    if (s == end_it) {
+      ldout(cct, 20) << "  s at end" << dendl;
+      auto& r = partial[tofs];
+      r.second = tlen;
+      total_intended_len += r.second;
+      break;
+    }
 
-      if (s->first > bl_off) {
-       // gap in sparse read result
-       pair<bufferlist, uint64_t>& r = partial[tofs];
-       size_t gap = std::min<size_t>(s->first - bl_off, tlen);
-       ldout(cct, 20) << "  s gap " << gap << ", skipping" << dendl;
-       r.second = gap;
-       total_intended_len += r.second;
-       bl_off += gap;
-       tofs += gap;
-       tlen -= gap;
-       if (tlen == 0) {
-         continue;
-       }
-      }
+    ldout(cct, 30) << "  s " << s->first << "~" << s->second << dendl;
 
-      ceph_assert(s->first <= bl_off);
-      size_t left = (s->first + s->second) - bl_off;
-      size_t actual = std::min(left, tlen);
-
-      if (actual > 0) {
-       ldout(cct, 20) << "  s has " << actual << ", copying" << dendl;
-       pair<bufferlist, uint64_t>& r = partial[tofs];
-       bl.splice(0, actual, &r.first);
-       r.second = actual;
-       total_intended_len += r.second;
-       bl_off += actual;
-       tofs += actual;
-       tlen -= actual;
-      }
-      if (actual == left) {
-       ldout(cct, 30) << "  s advancing" << dendl;
-       ++s;
+    // skip zero-length extent
+    if (s->second == 0) {
+      ldout(cct, 30) << "  s len 0, skipping" << dendl;
+      ++s;
+      continue;
+    }
+
+    if (s->first > *bl_off) {
+      // gap in sparse read result
+      pair<bufferlist, uint64_t>& r = partial[tofs];
+      size_t gap = std::min<size_t>(s->first - *bl_off, tlen);
+      ldout(cct, 20) << "  s gap " << gap << ", skipping" << dendl;
+      r.second = gap;
+      total_intended_len += r.second;
+      *bl_off += gap;
+      tofs += gap;
+      tlen -= gap;
+      if (tlen == 0) {
+        continue;
       }
     }
+
+    ceph_assert(s->first <= *bl_off);
+    size_t left = (s->first + s->second) - *bl_off;
+    size_t actual = std::min(left, tlen);
+
+    if (actual > 0) {
+      ldout(cct, 20) << "  s has " << actual << ", copying" << dendl;
+      pair<bufferlist, uint64_t>& r = partial[tofs];
+      bl.splice(0, actual, &r.first);
+      r.second = actual;
+      total_intended_len += r.second;
+      *bl_off += actual;
+      tofs += actual;
+      tlen -= actual;
+    }
+    if (actual == left) {
+      ldout(cct, 30) << "  s advancing" << dendl;
+      ++s;
+    }
   }
 }
 

diff --git a/src/osdc/Striper.h b/src/osdc/Striper.h
index b3034d8204ba681d41cc5946bd74130887e5fa54..c7dc9c224fcc321a84b9523ae0d8d9195f208c69 100644 (file)
--- a/src/osdc/Striper.h
+++ b/src/osdc/Striper.h
@@ -85,6 +85,10 @@ class CephContext;
       void add_partial_result(
        CephContext *cct, ceph::buffer::list& bl,
        const std::vector<std::pair<uint64_t,uint64_t> >& buffer_extents);
+      void add_partial_result(
+         CephContext *cct, ceph::buffer::list&& bl,
+         const striper::LightweightBufferExtents& buffer_extents);
+
       /**
        * add sparse read into results
        *
@@ -98,8 +102,13 @@ class CephContext;
        CephContext *cct, ceph::buffer::list& bl,
        const std::map<uint64_t, uint64_t>& bl_map, uint64_t bl_off,
        const std::vector<std::pair<uint64_t,uint64_t> >& buffer_extents);
+      void add_partial_sparse_result(
+         CephContext *cct, ceph::buffer::list& bl,
+         const std::map<uint64_t, uint64_t>& bl_map, uint64_t bl_off,
+         const striper::LightweightBufferExtents& buffer_extents);
 
-      void assemble_result(CephContext *cct, ceph::buffer::list& bl, bool zero_tail);
+      void assemble_result(CephContext *cct, ceph::buffer::list& bl,
+                           bool zero_tail);
 
       /**
        * @buffer copy read data into buffer
@@ -110,6 +119,13 @@ class CephContext;
       void assemble_result(CephContext *cct,
                            std::map<uint64_t, uint64_t> *extent_map,
                            ceph::buffer::list *bl);
+
+    private:
+      void add_partial_sparse_result(
+          CephContext *cct, bufferlist& bl,
+          std::map<uint64_t, uint64_t>::const_iterator* it,
+          const std::map<uint64_t, uint64_t>::const_iterator& end_it,
+          uint64_t* bl_off, uint64_t tofs, uint64_t tlen);
     };
 
   };