fixed new bug in buffer encoding, finally implemented a proper substr that returns...

git-svn-id: https://ceph.svn.sf.net/svnroot/ceph@1712 29311d96-e01e-0410-9327-a35deaab8ce9

diff --git a/trunk/ceph/include/buffer.h b/trunk/ceph/include/buffer.h
index 13f9fe4cc9c22907f8eebe7dde46edbe54e1b69e..b3388d36acbfbe214f593c305e6b7a8aa92bee68 100644 (file)
--- a/trunk/ceph/include/buffer.h
+++ b/trunk/ceph/include/buffer.h
@@ -681,23 +681,18 @@ public:
       
       // skip off
       std::list<ptr>::const_iterator curbuf = other._buffers.begin();
-      while (off > 0) {
-       assert(curbuf != _buffers.end());
-       if (off >= (*curbuf).length()) {
-         // skip this buffer
-         //cout << "skipping over " << *curbuf << std::endl;
-         off -= (*curbuf).length();
-         curbuf++;
-       } else {
-         // somewhere in this buffer!
-         //cout << "somewhere in " << *curbuf << std::endl;
-         break;
-       }
+      while (off > 0 &&
+            off >= curbuf->length()) {
+       // skip this buffer
+       //cout << "skipping over " << *curbuf << std::endl;
+       off -= (*curbuf).length();
+       curbuf++;
       }
+      assert(len == 0 || curbuf != other._buffers.end());
       
       while (len > 0) {
        // partial?
-       if (off + len < (*curbuf).length()) {
+       if (off + len < curbuf->length()) {
          //cout << "copying partial of " << *curbuf << std::endl;
          _buffers.push_back( ptr( *curbuf, off, len ) );
          _len += len;
@@ -706,7 +701,7 @@ public:
        
        // through end
        //cout << "copying end (all?) of " << *curbuf << std::endl;
-       unsigned howmuch = (*curbuf).length() - off;
+       unsigned howmuch = curbuf->length() - off;
        _buffers.push_back( ptr( *curbuf, off, howmuch ) );
        _len += howmuch;
        len -= howmuch;
@@ -715,6 +710,42 @@ public:
       }
     }
 
+    std::string substr(unsigned off, unsigned len) {
+      std::string s;
+      //cout << "substr " << off << "~" << len << " of " << length() << std::endl;
+
+      // skip off
+      std::list<ptr>::const_iterator curbuf = _buffers.begin();
+      while (off > 0 &&
+            off >= (*curbuf).length()) {
+       // skip this buffer
+       //cout << "skipping over " << *curbuf << std::endl;
+       off -= (*curbuf).length();
+       curbuf++;
+      }
+      assert(len == 0 || curbuf != _buffers.end());
+
+      while (len > 0) {
+       // partial?
+       if (off + len < curbuf->length()) {
+         //cout << "copying partial of " << *curbuf << std::endl;
+         s.append(curbuf->c_str() + off, len);
+         break;
+       }
+       
+       // through end
+       //cout << "copying end (all?) of " << *curbuf << std::endl;
+       unsigned howmuch = curbuf->length() - off;
+       s.append(curbuf->c_str() + off, howmuch);
+       len -= howmuch;
+       off = 0;
+       curbuf++;
+      }
+
+      //cout << "done, got " << s.length() << std::endl;
+      return s;
+    }
+
 
     // funky modifer
     void splice(unsigned off, unsigned len, list *claim_by=0 /*, bufferlist& replace_with */) {    // fixme?
@@ -1016,7 +1047,7 @@ inline void _decode(std::string& s, bufferlist& bl, int& off)
 {
   uint32_t len;
   _decoderaw(len, bl, off);
-  s = bl.c_str() + off;    // FIXME someday to avoid a huge buffer copy?
+  s = bl.substr(off, len);
   off += len;
 }