Merge the 2571 double-buffering stuff over and delete the 2571 branch. Double...

Merge the 2571 double-buffering stuff over and delete the 2571 branch.  Double buffering of the file merge is complete.  Fixes #2571. close[t:2571]
{{{
svn merge -r 20199:20206 https://svn.tokutek.com/tokudb/toku/tokudb.2571
}}}
.


git-svn-id: file:///svn/toku/tokudb@20208 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/brtloader-internal.h

@@ -58,7 +58,7 @@ void destroy_rowset (struct rowset *rows);
 void add_row (struct rowset *rows, DBT *key, DBT *val);
 
 int loader_write_row(DBT *key, DBT *val, FIDX data, FILE*, u_int64_t *dataoff, BRTLOADER bl);
-int loader_read_row (FILE *f, DBT *key, DBT *val, BRTLOADER bl);
+int loader_read_row (FILE *f, DBT *key, DBT *val);
 
 struct merge_fileset {
     int n_temp_files, n_temp_files_limit;

newbrt/tests/brtloader-test.c

@@ -201,7 +201,7 @@ static void test_read_write_rows (char *template) {
     {
 	int n_read=0;
 	DBT key={.size=0}, val={.size=0};
-	while (0==loader_read_row(toku_bl_fidx2file(&bl, file), &key, &val, &bl)) {
+	while (0==loader_read_row(toku_bl_fidx2file(&bl, file), &key, &val)) {
 	    assert(strlen(keystrings[n_read])==key.size);
 	    assert(strlen(valstrings[n_read])==val.size);
 	    assert(0==memcmp(keystrings[n_read], key.data, key.size));

src/loader.c

@@ -57,6 +57,7 @@ struct __toku_loader_internal {
  *  free_loader_resources() frees all of the resources associated with
  *      struct __toku_loader_internal 
  *  assumes any previously freed items set the field pointer to NULL
+ *  Requires that the brt_loader is closed or destroyed before calling this function.
  */
 static void free_loader_resources(DB_LOADER *loader) 
 {
@@ -86,7 +87,6 @@ static void free_loader_resources(DB_LOADER *loader)
             toku_free(loader->i->inames_in_env);
         }
         if (loader->i->temp_file_template) toku_free(loader->i->temp_file_template);
-        if (loader->i->brt_loader)         toku_free(loader->i->brt_loader);
 
         // loader->i
         toku_free(loader->i);