From: Peter Stamfest <peter@stamfest.at>
Date: Fri, 28 Feb 2014 20:48:47 +0000 (+0100)
Subject: Rip out a lot of too complicated code doing reordering of
X-Git-Tag: v1.5.0-rc1~131^2~19
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=13f6d0f68b9150ab21f5ed9127f0a2dbc853949c;p=thirdparty%2Frrdtool-1.x.git

Rip out a lot of too complicated code doing reordering of
RRA rows. This is now done during the copying of the data to the
out RRA. This should also assist with the upcoming planned
population of newly added RRAs or RRA rows.
---

diff --git a/src/rrd_modify.c b/src/rrd_modify.c
index 8503a4a0..0383165c 100644
--- a/src/rrd_modify.c
+++ b/src/rrd_modify.c
@@ -404,63 +404,17 @@ static int rrd_modify_r(const char *infilename,
 	ssize_t rra_size     = sizeof(rrd_value_t) * rra_values;
 	ssize_t rra_size_out = sizeof(rrd_value_t) * rra_values_out;
 
-	/* reorder data by cleaverly reading it into the right place */
-
-	/*
-	  Data in the RRD file:
-	                             
-	  <-------------RRA-------------->
-	  BBBBBBBBBBBBBBBBBBBBBAAAAAAAAAAA
-          ^                    ^          ^
-          0                 cur_row    row_cnt
-
-	  Data in memory should become
-	                             
-	  <-------------RRA-------------->
-          AAAAAAAAAAABBBBBBBBBBBBBBBBBBBBB
-	  ^          ^                    ^
-       cur_row=0     n                 row_cnt
-
-	  using:   n = row_cnt - cur_row
-
-	  we first read cur_row values to position n and then n values to 
-	  position 0.
-
-	 */
-
-	/* instead of the actual cur_row, we have to add 1, because
-	   cur_row does not point to the next "free", but the
-	   currently in use position */
-	int last = (in.rra_ptr[i].cur_row + 1) % in.rra_def[i].row_cnt; 
-	int n = in.rra_def[i].row_cnt - last;
-
-	size_t to_read = last * sizeof(rrd_value_t) * in.stat_head->ds_cnt;
+	size_t to_read = in.rra_def[i].row_cnt * sizeof(rrd_value_t) * in.stat_head->ds_cnt;
 	size_t read_bytes;
 
-	if (to_read > 0) {
-	    read_bytes = 
-		rrd_read(rrd_file, 
-			 all_data + rra_start + 
-			 n * sizeof(rrd_value_t) * in.stat_head->ds_cnt, 
-			 to_read);	
-	    
-	    if (read_bytes != to_read) {
-		rrd_set_error("short read 1");
-		goto done;
-	    }
-	}
-
-	to_read = n * sizeof(rrd_value_t) * in.stat_head->ds_cnt ;
-	if (to_read > 0) {
-	    read_bytes = 
-		rrd_read(rrd_file, 
-			 all_data + rra_start,
-			 to_read);
-	    
-	    if (read_bytes != to_read) {
-		rrd_set_error("short read 2");
-		goto done;
-	    }
+	read_bytes = 
+	    rrd_read(rrd_file, 
+		     all_data + rra_start,
+		     to_read);
+	
+	if (read_bytes != to_read) {
+	    rrd_set_error("short read 2");
+	    goto done;
 	}
 
 	/* we now have all the data for the current RRA available, now
@@ -519,20 +473,23 @@ static int rrd_modify_r(const char *infilename,
 	    }
 	}
 
+	/* now do the actual copying of data */
+
 	for ( ; ii < in.rra_def[i].row_cnt 
 		  && oi < out.rra_def[out_rra].row_cnt ; ii++, oi++) {
+	    int real_ii = (ii + in.rra_ptr[i].cur_row + 1) % in.rra_def[i].row_cnt;
 	    for (j = jj = 0 ; j < ops_cnt ; j++) {
 		switch (ops[j]) {
 		case 'c': {
 		    out.rrd_value[total_cnt_out + oi * out.stat_head->ds_cnt + jj] =
-			in.rrd_value[total_cnt + ii * in.stat_head->ds_cnt + j];
+			in.rrd_value[total_cnt + real_ii * in.stat_head->ds_cnt + j];
 
 		    /* it might be better to use memcpy, actually (to
 		       treat them opaquely)... so keep the code for
 		       the time being */
 		    /*
 		    memcpy((void*) (out.rrd_value + total_cnt_out + oi * out.stat_head->ds_cnt + jj),
-			   (void*) (in.rrd_value + total_cnt + ii * in.stat_head->ds_cnt + j), sizeof(rrd_value_t));
+			   (void*) (in.rrd_value + total_cnt + real_ii * in.stat_head->ds_cnt + j), sizeof(rrd_value_t));
 		    */			   
 		    jj++;
 		    break;