--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pvl/rrd/hosts.py	Thu Jul 04 03:49:27 2013 +0300
@@ -0,0 +1,117 @@
+"""
+    Handle host-interface mappings for stats.
+"""
+
+import shlex
+import os.path
+
+import logging; log = logging.getLogger('pvl.rrd.hosts')
+
+def hostjoin (*hosts) :
+    """
+        DNS hostname join.
+    """
+
+    return '.'.join(hosts)
+
+def hostreverse (host) :
+    """
+        Reverse hostname.
+    """
+    
+    return '.'.join(reversed(host.split('.')))
+
+def load (file, domain=None) :
+    """
+        Parse hosts from file, yielding
+            (host, node, iface, tag)
+            
+            file            - read host/ifaces from file
+            domain          - append given domain to hostname
+    """
+    
+    host = None
+
+    for idx, line in enumerate(file, 1) :
+        line = line.rstrip()
+
+        if not line :
+            continue
+        
+        # comment?
+        if line.startswith('#') :
+            continue
+        
+        # line
+        parts = shlex.split(line)
+
+        if not line[0].isspace() :
+            host = parts.pop(0)
+        
+            # host-spec?
+            if '=' in host :
+                host, node = host.split('=')
+            else :
+                node = host
+            
+            # host has domain in collectd?
+            if domain :
+                host = hostjoin(host, domain)
+
+        if not parts :
+            # keep host for following lines
+            continue
+
+        iface = parts.pop(0)
+ 
+        # possibly multiple tags..
+        for tag in parts :
+            yield host, node, iface, tag
+
+def map_interfaces (options, file):
+    """
+        Read (hostname, interface}: (nodename, tag) pairs from file.
+    """
+
+    for host, node, iface, tag in load(file) :
+        log.debug("%s/%s -> %s/%s", host, iface, node, tag)
+        yield (host, iface), (node, tag)
+
+def collectd_interfaces (options, file, collectd_domain, collectd_plugin) :
+    """
+        Read collectd (host, type-instance, name) items, and yield (collectd-rrd, out-rrd) tuples.
+            
+            file                - read host/ports from file
+            collectd_domain     - append given domain to collectd hostname
+            collectd_plugin     - use given collectd plugin's type-instances
+    """
+
+    log.info("scanning %s/<host>.%s/%s/%s-<port>.rrd", options.collectd_rrd, collectd_domain, collectd_plugin, options.collectd_type)
+
+    for collectd_host, interface_host, port, tag in load(file, domain=collectd_domain) :
+        # flip from DNS-ordering -> path-ordering
+        if options.reverse_host :
+            interface_host = hostreverse(interface_host)
+
+        if options.collectd_instance == 'type' :
+            type = options.collectd_type + '-' + port
+        else :
+            type = options.collectd_type
+
+        if options.collectd_instance == 'plugin' :
+            plugin = collectd_plugin + '-' + port
+        else :
+            plugin = collectd_plugin
+
+        collectd_rrd = os.path.join(options.collectd_rrd, collectd_host, plugin, type) + '.rrd'
+
+        if not os.path.exists(collectd_rrd) :
+            log.warn("%s/%s: missing collectd rrd: %s", collectd_host, port, collectd_rrd)
+            continue
+
+        # out
+        interface_rrd = os.path.join(interface_host, tag + '.rrd')
+
+        log.debug("%s: %s", interface_rrd, collectd_rrd)
+
+        yield collectd_rrd, interface_rrd