api: add new stream message convention

Instead of having to wrap dump/detail calls in control ping, send details messages in between a normal
reply / request pair. As expressed in the below service statement.

Example:

service {
  rpc map_domains_gets returns map_domains_get_reply
    stream map_domain_details;
};

define map_domains_get
{
  u32 client_index;
  u32 context;
  u32 cursor;
};

define map_domains_get_reply
{
  u32 context;
  i32 retval;
  u32 cursor;
};

To avoid blocking the main thread for too long, the replies are now sent in client message queue size
chunks. The reply message returns VNET_API_ERROR_EAGAIN when there is more to read.
The API handler must also include a "cursor" that is used to the next call to the get function.

API handler example:
  REPLY_AND_DETAILS_MACRO (VL_API_MAP_DOMAINS_GET_REPLY, mm->domains,
  ({
    send_domain_details (cursor, rp, mp->context);
  }));

The macro starts from cursor and iterates through the pool
until vl_api_process_may_suspend() returns true or the iteration
reaches the end of the list.

Client Example:

cursor = 0
d = []
while True:
    rv, details = map_domains_get(cursor=cursor)
    d += details
    if rv.retval == 0 or rv.retval != -165:
        break
    cursor = rv.cursor

or the convenience iterator:
for x in vpp.details_iter(vpp.api.map_domains_get):
  pass

or

list(details_iter(map_domains_get))

Change-Id: Iad9f6b41b0ef886adb584c97708dd91cf552749e
Type: feature
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/src/plugins/map/test/test_map.py b/src/plugins/map/test/test_map.py
index 59c23335052..93ea3f06976 100644
--- a/src/plugins/map/test/test_map.py
+++ b/src/plugins/map/test/test_map.py
@@ -100,6 +100,48 @@ class TestMAP(VppTestCase):
         self.assertEqual(rv[0].tag, tag,
                          "output produced incorrect tag value.")
 
+    def create_domains(self, ip4_pfx_str, ip6_pfx_str, ip6_src_str):
+        ip4_pfx = ipaddress.ip_network(ip4_pfx_str)
+        ip6_dst = ipaddress.ip_network(ip6_pfx_str)
+        mod = ip4_pfx.num_addresses / 1024
+        indicies = []
+        for i in range(ip4_pfx.num_addresses):
+            rv = self.vapi.map_add_domain(ip6_prefix=ip6_pfx_str,
+                                          ip4_prefix=str(ip4_pfx[i]) + "/32",
+                                          ip6_src=ip6_src_str)
+            indicies.append(rv.index)
+        return indicies
+
+    def test_api_map_domains_get(self):
+        # Create a bunch of domains
+        domains = self.create_domains('130.67.0.0/24', '2001::/32',
+                                      '2001::1/128')
+        self.assertEqual(len(domains), 256)
+
+        d = []
+        cursor = 0
+
+        # Invalid cursor
+        rv, details = self.vapi.map_domains_get(cursor=1234)
+        self.assertEqual(rv.retval, -7)
+
+        # Delete a domain in the middle of walk
+        rv, details = self.vapi.map_domains_get(cursor=0)
+        self.assertEqual(rv.retval, -165)
+        self.vapi.map_del_domain(index=rv.cursor)
+        domains.remove(rv.cursor)
+
+        # Continue at point of deleted cursor
+        rv, details = self.vapi.map_domains_get(cursor=rv.cursor)
+        self.assertEqual(rv.retval, -165)
+
+        d = list(self.vapi.vpp.details_iter(self.vapi.map_domains_get))
+        self.assertEqual(len(d), 255)
+
+        # Clean up
+        for i in domains:
+            self.vapi.map_del_domain(index=i)
+
     def test_map_e_udp(self):
         """ MAP-E UDP"""
 
@@ -916,5 +958,6 @@ class TestMAP(VppTestCase):
                                                 ip6_nh_address="4001::1",
                                                 is_add=0)
 
+
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)