Merge branch 'master' of https://gitlab.elettra.eu/puma/server/ca-tango-db-cache-mgr

README.md

@@ -56,5 +56,91 @@ package is not installed system-wide
 
 ### request syntax
 
-> curl -v http://woody.elettra.eu:9296 -d $'{"srcs":[{"src":"test/device/1/double_scalar"}]}'
+#### Subscribe to the attribute configuration change event and cache the configuration
+
+Source *test/device/1/double_scalar*
+
+> curl http://woody.elettra.eu:9296 -d $'{"srcs":[{"src":"test/device/1/double_scalar"}]}'
+
+Three sources:
+
+> curl -v http://taeyang.elettra.eu:9296 -d $'{"srcs":[{"src":"test/device/1/double_scalar"},{"src":"test/device/1/long_scalar"},{"src":"test/device/1/short_scalar"}]}'
+
+The first source will be processed immediately, the others according to the 
+
+``` 
+ca-tango-db-cache-mgr:subscribe-rate 
+```
+
+option in the configuration file (subscribe rate per second: default: two subscriptions per second)
+
+##### Expected reply
+
+```json
+{"msg":"ok","pos":0,"queue-cnt":3,"scheduled-cnt":3}
+```
+
+#### List the subscribed sources (method: "l")
+
+> curl -v http://taeyang.elettra.eu:9296 -d $'{"method":"l"}'
+
+##### Expected reply
+
+```json
+{"srcs":[{"src":"test/device/1/double_scalar"},{"src":"test/device/1/long_scalar"},{"src":"test/device/1/short_scalar"}]}
+```
+
+#### Process immediately all the queued sources (method "p")
+
+If you want to subscribe immediately all the sources in the queue regardless the maximum rate per second 
+specified in the configuration:
+
+> curl http://taeyang.elettra.eu:9296 -d $'{"method":"p"}'
+
+##### Expected reply
+
+```json
+{
+          "count": 2,
+          "srcs": [
+                    {
+                              "msg": "ok",
+                              "src": "test/device/1/long_scalar"
+                    },
+                    {
+                              "msg": "ok",
+                              "src": "test/device/1/short_scalar"
+                    }
+          ]
+}
+
+```
+
+#### Unsubscribe a set of sources (method: "u")
+
+Unsubscribe *double_scalar* and *long_scalar* from *test/device/1*:
+
+> curl -v http://taeyang.elettra.eu:9296 -d $'{"method":"u", "srcs":[{"src":"test/device/1/double_scalar"},{"src":"test/device/1/long_scalar"}]}'
+
+#### Expected reply
+
+If the two sources were being monitored:
+
+```json
+{"count":2,"method":"u","removed":2,"srcs":[{"msg":"ok","src":"test/device/1/double_scalar"},{"msg":"ok","src":"test/device/1/long_scalar"}]}
+```
+
+In case of error (let's remove the two sources above twice):
+
+```json
+{"count":2,"method":"u","removed":0,"srcs":[{"msg":"attribute double_scalar not found (devicetest/device/1)","src":"test/device/1/double_scalar"},{"msg":"attribute long_scalar not found (devicetest/device/1)","src":"test/device/1/long_scalar"}]}
+```
+
+#### Read the saved configuration for a set of sources (method:"r")
+
+This method can be useful to measure the time it takes to retrieve the configuration from the cache.
+It can be compared with the time taken to query the Tango Database directly to get the same piece of
+information.
+
+