demo redis quota

demos/demo-redis-quota/README.md

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+First, setup redis: bash setup.sh to install redis in ubuntu for thest
+
+To test, fill a prefix with some random keys (1k each)
+bash fill.sh <prefix> <n>
+
+Then you can check providing the prefixes to check (as I assume we know them )""
+
+bash check.sh <prefx> <prefix>...
+
+Example
+
+```
+bash fill.sh mike 100
+bash check.sh mike franz
+bash fill.sh franz 200
+bash check.sh mike franz
+```

demos/demo-redis-quota/check.sh

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+#!/bin/bash
+SCRIPT=$(redis-cli SCRIPT LOAD "$(cat size_by_prefix.lua)")
+for i in "$@"
+do redis-cli EVALSHA $SCRIPT 0 "$i:"
+done

demos/demo-redis-quota/fill.sh

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+#!/bin/bash
+PREFIX=${1?:prefix}
+N=${2?:count}
+X=$(printf "x%.0s" {1..1024})
+for i in $(seq 1 $N)
+do K=$RANDOM
+   echo $i $K
+   redis-cli set $PREFIX:$K "$X"
+done

demos/demo-redis-quota/setup.sh

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+sudo apt-get install redis-server redis-tools
+sudo systemctl start redis-server
+sudo systemctl status redis-server
+

demos/demo-redis-quota/size_by_prefix.lua

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+-- Define the key prefix to search for
+local prefix = ARGV[1]
+local cursor = 0
+local total_memory = 0
+
+repeat
+    -- Use SCAN to get keys that match the prefix
+    local result = redis.call('SCAN', cursor, 'MATCH', prefix .. '*')
+    cursor = tonumber(result[1])
+    local keys = result[2]
+
+    for _, key in ipairs(keys) do
+        -- Get memory usage of each key and add it to the total
+        local memory_usage = redis.call('MEMORY', 'USAGE', key)
+        if memory_usage then
+            total_memory = total_memory + memory_usage
+        end
+    end
+until cursor == 0
+
+return total_memory