All other layers to register their own print-attribute functions so we can maintain pretty-print capabilities as the attributes are extended.

orte/util/attr.c

@@ -19,13 +19,26 @@
 
 #include "orte/util/attr.h"
 
+#define MAX_CONVERTERS 5
+#define MAX_CONVERTER_PROJECT_LEN 10
+
+typedef struct {
+    int init;
+    char project[MAX_CONVERTER_PROJECT_LEN];
+    orte_attribute_key_t key_base;
+    orte_attribute_key_t key_max;
+    orte_attr2str_fn_t converter;
+} orte_attr_converter_t;
+
+/* all default to NULL */
+static orte_attr_converter_t converters[MAX_CONVERTERS];
+
 static int orte_attr_unload(orte_attribute_t *kv,
                             void **data, opal_data_type_t type);
 
 static int orte_attr_load(orte_attribute_t *kv,
                           void *data, opal_data_type_t type);
 
-
 bool orte_get_attribute(opal_list_t *attributes,
                         orte_attribute_key_t key,
                         void **data, opal_data_type_t type)
@@ -94,8 +107,35 @@ void orte_remove_attribute(opal_list_t *attributes, orte_attribute_key_t key)
     }
 }
 
+int orte_attr_register(const char *project,
+                       orte_attribute_key_t key_base,
+                       orte_attribute_key_t key_max,
+                       orte_attr2str_fn_t converter)
+{
+    int i;
+
+    for (i = 0 ; i < MAX_CONVERTERS ; ++i) {
+        if (0 == converters[i].init) {
+            converters[i].init = 1;
+            strncpy(converters[i].project, project, MAX_CONVERTER_PROJECT_LEN);
+            converters[i].project[MAX_CONVERTER_PROJECT_LEN-1] = '\0';
+            converters[i].key_base = key_base;
+            converters[i].key_max = key_max;
+            converters[i].converter = converter;
+            return ORTE_SUCCESS;
+        }
+    }
+
+    return ORTE_ERR_OUT_OF_RESOURCE;
+}
+
 const char *orte_attr_key_to_str(orte_attribute_key_t key)
 {
+    int i;
+    
+    if (ORTE_ATTR_KEY_BASE < key &&
+        key < ORTE_ATTR_KEY_MAX) {
+        /* belongs to ORTE, so we handle it */
         switch(key) {
         case ORTE_APP_HOSTFILE:
             return "APP-HOSTFILE";
@@ -240,6 +280,20 @@ const char *orte_attr_key_to_str(orte_attribute_key_t key)
         }
     }
 
+    /* see if one of the converters can handle it */
+    for (i = 0 ; i < MAX_CONVERTERS ; ++i) {
+        if (0 != converters[i].init) {
+            if (converters[i].key_base < key && 
+                key < converters[i].key_max) {
+                return converters[i].converter(key);
+            }
+        }
+    }
+
+    /* get here if nobody know what to do */
+    return "UNKNOWN-KEY";
+}
+
 
 static int orte_attr_load(orte_attribute_t *kv,
                           void *data, opal_data_type_t type)

orte/util/attr.h

@@ -19,6 +19,9 @@
 #define ORTE_ATTR_LOCAL    true      // for local use only
 #define ORTE_ATTR_GLOBAL   false     // include when sending this object
 
+/* define the mininum value of the ORTE keys just in
+ * case someone someday puts a layer underneath us */
+#define ORTE_ATTR_KEY_BASE        0
 
 /*** ATTRIBUTE FLAGS - never sent anywwhere ***/
 typedef uint8_t orte_app_context_flags_t;
@@ -160,7 +163,7 @@ typedef uint16_t orte_proc_flags_t;
 
 #define ORTE_PROC_MAX_KEY   400
 
-#define ORTE_MAX_ATTR_KEY  1000
+#define ORTE_ATTR_KEY_MAX  1000
 
 
 /*** FLAG OPS ***/
@@ -181,5 +184,16 @@ ORTE_DECLSPEC int orte_set_attribute(opal_list_t *attributes, orte_attribute_key
 /* Remove the named attribute from a list */
 ORTE_DECLSPEC void orte_remove_attribute(opal_list_t *attributes, orte_attribute_key_t key);
 
+/*
+ * Register a handler for converting attr keys to strings
+ *
+ * Handlers will be invoked by orte_attr_key_to_str to return the appropriate value.
+ */
+typedef char* (*orte_attr2str_fn_t)(int key);
+
+ORTE_DECLSPEC int orte_attr_register(const char *project,
+                                     orte_attribute_key_t key_base,
+                                     orte_attribute_key_t key_max,
+                                     orte_attr2str_fn_t converter);
 
 #endif