[Assorted-commits] SF.net SVN: assorted: [391] cpp-commons/trunk/src/commons/region.h

[<yan...@us...>]

Revision: 391
          http://assorted.svn.sourceforge.net/assorted/?rev=391&view=rev
Author:   yangzhang
Date:     2008-02-12 09:08:58 -0800 (Tue, 12 Feb 2008)

Log Message:
-----------
added support for arbitrary-sized allocations

Modified Paths:
--------------
    cpp-commons/trunk/src/commons/region.h

Modified: cpp-commons/trunk/src/commons/region.h
===================================================================
--- cpp-commons/trunk/src/commons/region.h	2008-02-12 16:45:07 UTC (rev 390)
+++ cpp-commons/trunk/src/commons/region.h	2008-02-12 17:08:58 UTC (rev 391)
@@ -16,45 +16,62 @@
   const size_t default_chunk_size = 100000000;
 
   /**
+   * A fixed-size buffer (really just a pair of length and pointer).
+   */
+  struct chunk
+  {
+    size_t size;
+    char* data;
+  };
+
+  /**
    * Simple dynamically growing memory region that does not support
    * deallocation.
    */
   class mem_region
   {
   private:
-    vector<char*> chunks;
+    vector<chunk> chunks;
+    /**
+     * The default chunk-size when incrementally resizing; we can still handle
+     * larger allocations.
+     */
     const size_t chunk_size;
     size_t top;
-    int    m_refcount;
+    int    refcount;
 
   public:
     mem_region() :
       chunk_size(default_chunk_size),
       top(0),
-      m_refcount(0)
+      refcount(0)
     {
-      chunks.push_back(new char[chunk_size]);
+      chunks.push_back((chunk) {chunk_size, new char[chunk_size]});
     }
 
     ~mem_region()
     {
+      // cout << "deleting" << endl;
       for (unsigned int i = 0; i < chunks.size(); i++) {
-        delete [] chunks[i];
+        delete [] chunks[i].data;
       }
     }
 
-    void addref() { ++m_refcount; }
-    void decref() { if (--m_refcount == 0) { delete this; } }
+    void addref() { ++refcount; }
+    void decref() { if (--refcount == 0) { delete this; } }
 
     void *alloc_mem(size_t n)
     {
       if (top + n > chunk_size) {
-        chunks.push_back(new char[chunk_size]);
+        // chunks.push_back(new char[chunk_size]);
+	size_t sz = max(n, chunk_size);
+	chunks.push_back((chunk) {sz, new char[sz] });
         top = 0;
       }
+      // cout << "alloced" << endl;
       size_t old_top = top;
       top += n;
-      return chunks.back() + old_top;
+      return chunks.back().data + old_top;
     }
   };
 


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