Redis Counting

[vulcan25]

Here's a cool feature at commit: 95e5a23

REDIS COUNTS YEAAA.

Since we're already using redis in the project, it's pretty trival to add counts, using Redis' HINCRBY.

Basically we create a redis hash, which at the moment is obj_cnt:default with a field for each item.

So you can curl a few images as usual, then hit the following endpoint to get a list of overall counts, for images submitted through the system:

curl http://localhost:5001/counts
{"handbag":"4","person":"16","sports ball":"4"}

This may be useful if you're submitting a whole load of images, and what to keep track of what was found in those images.

Notice in that commit I've also grabbed the threshold from the env var COUNT_THRESHOLD

This lets you set it in the docker-compose.yml file. Something like:

services:
  processor:
    environment:
      - COUNT_THRESHOLD=0.40

Now only results above that threshold will be counted. If it's not set there it defaults to 0.

---

If you want, you can also check this out from inside the redis container:

docker exec -it image_processor_redis_1 redis-cli 

Then use the HGETALL command to see the counts for everything in the specified field:

127.0.0.1:6379> keys *
1) "obj_cnt:default"
127.0.0.1:6379> HGETALL obj_cnt:default
1) "sports ball"
2) "1"
3) "handbag"
4) "1"
5) "person"
6) "4"

Run the curl command again to import, then reissue the command and they should increment.

---

TODOs for this

• dynamically specify a counter_id. I envision this working so if the upload request hits example.com/some_portal, the counter_id will be set as some_portal. From the frontend, this would let you submit different image 'batches' to different endpoints and get back the relevant counts, theoretically by hitting example.com/counts/some_portal. Probably this needs to be implemented carefully so it can't be doss'ed by people submitting really long keys (some validation required on the counter_id string).

• Maybe tie this into a frontend template.