host merge fixes

svn path=/trunk/boinc/; revision=8738

checkin_notes

@@ -13297,3 +13297,21 @@ Charlie 21 Oct 2005
     mac_build/
         boinc.pbproj/
             project.pbxproj
+
+David  22 Oct 2005
+	- Prevent the "merge host" feature from being used
+		to merge distinct hosts
+		(and create host records with exaggerated credit totals).
+		Hosts X and Y are considered "compatible" (for merging)
+			only if X.rpc_time < Y.create_time or vice-versa.
+	- When merging hosts X and Y,
+		a) decay their expavg_credit prior to adding and updating
+		b) set create_time to the min of the two
+		c) if the target is older, update its rpc_time and rpc_seqno
+
+	html/
+		inc/
+			host.inc
+		user/
+			host_edit_action.php
+			host_edit_form.php

html/inc/host.inc

@@ -248,6 +248,9 @@ function ghz($x) {
     }
 }
 
+// return true if it's possible that the two host records
+// correspond to the same host
+//
 function hosts_compatible($host1, $host2) {
     // we screwed around with Intel processor names,
     // so count them as compatible if both contain "Intel" and "Pentium",
@@ -266,7 +269,12 @@ function hosts_compatible($host1, $host2) {
         if ($host2->p_model != $host1->p_model) return false;
     }
     if ($host2->os_name != $host1->os_name) return false;
-    return true;
+
+	// one host must strictly precede the other
+	//
+	if ($host1.rpc_time < $host2.create_time) return true;
+	if ($host2.rpc_time < $host1.create_time) return true;
+    return false;
 }
 
 // recompute host's average credit by scanning results.

html/user/host_edit_action.php

@@ -27,14 +27,21 @@ function merge_hosts($old_host, $new_host) {
 
     echo "<br>Merging host $old_host->id into host $new_host->id\n";
 
+	// decay the average credit of both hosts
+	//
+	$now = time();
+	update_average($now, 0, 0, $old_host->expavg_credit, $old_host->expavg_time);
+	update_average($now, 0, 0, $new_host->expavg_credit, $new_host->expavg_time);
+
     // update the database:
     // - add credit from old to new host
     // - change results to refer to new host
+	// - update create and RPC times
     // - put old host in "zombie" state
     //
     $total_credit = $old_host->total_credit + $new_host->total_credit;
     $recent_credit = $old_host->expavg_credit + $new_host->expavg_credit;
-    $result = mysql_query("update host set total_credit=$total_credit, expavg_credit=$recent_credit where id=$new_host->id");
+    $result = mysql_query("update host set total_credit=$total_credit, expavg_credit=$recent_credit, $expavg_time=$now where id=$new_host->id");
     if (!$result) {
         fail("Couldn't update credit of new computer");
     }
@@ -42,42 +49,57 @@ function merge_hosts($old_host, $new_host) {
     if (!$result) {
         fail("Couldn't update results");
     }
+
+	if ($old_host->rpc_time < $new_host->create_time) {
+		$query = "update host set create_time=$old_host->create_time where id=$new_host->id";
+		$result = mysql_query($query);
+		if (!$result) {
+			fail("Couldn't update times");
+		}
+	}
+	if ($new_host->rpc_time < $old_host->create_time) {
+		$query = "update host set rpc_time=$old_host->rpc_time, rpc_seqno=$old_host->rpc_seqno where id=$new_host->id";
+		$result = mysql_query($query);
+		if (!$result) {
+			fail("Couldn't update times");
+		}
+	}
     $result = mysql_query("update host set total_credit=0, expavg_credit=0, userid=0, rpc_seqno=$new_host->id where id=$old_host->id");
     if (!$result) {
-        fail("Couldn't update old computer");
+        fail("Couldn't retire old computer");
     }
     echo "<br>Retired old computer $old_host->id\n";
 }
 
-    db_init();
-    $user = get_logged_in_user();
+db_init();
+$user = get_logged_in_user();
 
-    page_head("Merge computer records");
+page_head("Merge computer records");
 
-    $nhosts = $_GET["nhosts"];
-    $hostid = $_GET["id_0"];
-    $latest_host = get_host($hostid, $user);
-    for ($i=1; $i<$nhosts; $i++) {
-        $var = "id_$i";
-        $hostid = $_GET[$var];
-        if (!$hostid) continue;
-        $host = get_host($hostid, $user);
-        if ($host->create_time > $latest_host->create_time) {
-            merge_hosts($latest_host, $host);
-            $latest_host = $host;
-        } else {
-            merge_hosts($host, $latest_host);
-        }
-        // reread latest_host from database since we just
-        // updated its credits
-        //
-        $latest_host = lookup_host($latest_host->id);
-    }
-    echo "
-        <p><a href=hosts_user.php>Return to list of your computers</a>
-    ";
-    page_tail();
+$nhosts = $_GET["nhosts"];
+$hostid = $_GET["id_0"];
+$latest_host = get_host($hostid, $user);
+for ($i=1; $i<$nhosts; $i++) {
+	$var = "id_$i";
+	$hostid = $_GET[$var];
+	if (!$hostid) continue;
+	$host = get_host($hostid, $user);
+	if ($host->create_time > $latest_host->create_time) {
+		merge_hosts($latest_host, $host);
+		$latest_host = $host;
+	} else {
+		merge_hosts($host, $latest_host);
+	}
+	// reread latest_host from database since we just
+	// updated its credits
+	//
+	$latest_host = lookup_host($latest_host->id);
+}
+echo "
+	<p><a href=hosts_user.php>Return to list of your computers</a>
+";
+page_tail();
 
-    //Header("Location: show_host_detail.php?hostid=$latest_host->id");
+//Header("Location: show_host_detail.php?hostid=$latest_host->id");
 
 ?>

html/user/host_edit_form.php

@@ -33,7 +33,6 @@ start_table();
 row_heading_array(array("", "name", "created", "computer ID"));
 while ($host2 = mysql_fetch_object($result)) {
     if ($host->id == $host2->id) continue;
-    //if ($host2->create_time > $host->create_time) continue;
     if (!hosts_compatible($host, $host2)) continue;
     $t = time_str($host2->create_time);
     $x = $host2->domain_name;