striper: expose method that works directrly from a map<>

Some callers will want to call the stripe method multiple times and
accumulate IO on a single result set.  Expose access to the map<> that was
previously internally used for this and do the map -> vector conversion
in a wrapper.

Signed-off-by: Sage Weil <sage@inktank.com>

diff --git a/src/osdc/Striper.cc b/src/osdc/Striper.cc
index cc5632ca05be8ca9abe063ba125bf1e3dce313a6..29346e269e56982530069e219607e1afe1f12534 100644 (file)
--- a/src/osdc/Striper.cc
+++ b/src/osdc/Striper.cc
@@ -31,17 +31,28 @@ void Striper::file_to_extents(CephContext *cct, const char *object_format,
                            uint64_t offset, uint64_t len,
                            vector<ObjectExtent>& extents,
                            uint64_t buffer_offset)
+{
+  map<object_t,vector<ObjectExtent> > object_extents;
+  file_to_extents(cct, object_format, layout, offset, len, object_extents, buffer_offset);
+  assimilate_extents(object_extents, extents);
+}
+
+void Striper::file_to_extents(CephContext *cct, const char *object_format,
+                             ceph_file_layout *layout,
+                             uint64_t offset, uint64_t len,
+                             map<object_t,vector<ObjectExtent> >& object_extents,
+                             uint64_t buffer_offset)
 {
   ldout(cct, 10) << "file_to_extents " << offset << "~" << len 
                 << " format " << object_format
                 << dendl;
   assert(len > 0);
 
-  /* we want only one extent per object!
+  /*
+   * we want only one extent per object!
    * this means that each extent we read may map into different bits of the 
    * final read buffer.. hence OSDExtent.buffer_extents
    */
-  map< object_t, ObjectExtent > object_extents;
   
   __u32 object_size = layout->fl_object_size;
   __u32 su = layout->fl_stripe_unit;
@@ -66,16 +77,6 @@ void Striper::file_to_extents(CephContext *cct, const char *object_format,
     snprintf(buf, sizeof(buf), object_format, (long long unsigned)objectno);
     object_t oid = buf;
 
-    ObjectExtent *ex = 0;
-    if (object_extents.count(oid)) 
-      ex = &object_extents[oid];
-    else {
-      ex = &object_extents[oid];
-      ex->oid = oid;
-      ex->objectno = objectno;
-      ex->oloc = OSDMap::file_to_object_locator(*layout);
-    }
-    
     // map range into object
     uint64_t block_start = (stripeno % stripes_per_object) * su;
     uint64_t block_off = cur % su;
@@ -95,18 +96,24 @@ void Striper::file_to_extents(CephContext *cct, const char *object_format,
                   << " block_off " << block_off
                   << " " << x_offset << "~" << x_len
                   << dendl;
-    
-    if (ex->offset + (uint64_t)ex->length == x_offset) {
-      // add to extent
-      ldout(cct, 20) << " adding in to " << *ex << dendl;
-      ex->length += x_len;
-    } else {
-      // new extent
-      assert(ex->length == 0);
-      assert(ex->offset == 0);
+
+    ObjectExtent *ex = 0;
+    vector<ObjectExtent>& exv = object_extents[oid];
+    if (exv.empty() || exv.back().offset + exv.back().length != x_offset) {
+      exv.resize(exv.size() + 1);
+      ex = &exv.back();
+      ex->oid = oid;
+      ex->objectno = objectno;
+      ex->oloc = OSDMap::file_to_object_locator(*layout);
+
       ex->offset = x_offset;
       ex->length = x_len;
       ldout(cct, 20) << " added new " << *ex << dendl;
+    } else {
+      // add to extent
+      ex = &exv.back();
+      ldout(cct, 20) << " adding in to " << *ex << dendl;
+      ex->length += x_len;
     }
     ex->buffer_extents.push_back(make_pair(cur - offset + buffer_offset, x_len));
         
@@ -116,12 +123,18 @@ void Striper::file_to_extents(CephContext *cct, const char *object_format,
     left -= x_len;
     cur += x_len;
   }
-  
+}
+
+void Striper::assimilate_extents(map<object_t,vector<ObjectExtent> >& object_extents,
+                                vector<ObjectExtent>& extents)
+{
   // make final list
-  for (map<object_t, ObjectExtent>::iterator it = object_extents.begin();
+  for (map<object_t, vector<ObjectExtent> >::iterator it = object_extents.begin();
        it != object_extents.end();
        it++) {
-    extents.push_back(it->second);
+    for (vector<ObjectExtent>::iterator p = it->second.begin(); p != it->second.end(); ++p) {
+      extents.push_back(*p);
+    }
   }
 }
 

diff --git a/src/osdc/Striper.h b/src/osdc/Striper.h
index a90cd48cba38bf1c7913ef79d91be397fb51a2c5..9f0563514c1366ff794048527266be4f6e250a3f 100644 (file)
--- a/src/osdc/Striper.h
+++ b/src/osdc/Striper.h
@@ -28,6 +28,12 @@ class CephContext;
      * map (ino, layout, offset, len) to a (list of) OSDExtents (byte
      * ranges in objects on (primary) osds)
      */
+    static void file_to_extents(CephContext *cct, const char *object_format,
+                               ceph_file_layout *layout,
+                               uint64_t offset, uint64_t len,
+                               map<object_t, vector<ObjectExtent> >& extents,
+                               uint64_t buffer_offset=0);
+
     static void file_to_extents(CephContext *cct, const char *object_format,
                                ceph_file_layout *layout,
                                uint64_t offset, uint64_t len,
@@ -45,6 +51,9 @@ class CephContext;
       file_to_extents(cct, buf, layout, offset, len, extents);
     }
 
+    static void assimilate_extents(map<object_t,vector<ObjectExtent> >& object_extents,
+                                  vector<ObjectExtent>& extents);
+
     /**
      * reverse map an object extent to file extents
      */