[API-1] feat: search route

migrations/00000000000000_diesel_initial_setup/up.sql

@@ -34,3 +34,99 @@ BEGIN
     RETURN NEW;
 END;
 $$ LANGUAGE plpgsql;
+
+-- nanoid function
+CREATE EXTENSION IF NOT EXISTS pgcrypto;
+
+-- The `nanoid()` function generates a compact, URL-friendly unique identifier.
+-- Based on the given size and alphabet, it creates a randomized string that's ideal for
+-- use-cases requiring small, unpredictable IDs (e.g., URL shorteners, generated file names, etc.).
+-- While it comes with a default configuration, the function is designed to be flexible,
+-- allowing for customization to meet specific needs.
+DROP FUNCTION IF EXISTS nanoid(int, text, float);
+CREATE OR REPLACE FUNCTION nanoid(
+    size int DEFAULT 21, -- The number of symbols in the NanoId String. Must be greater than 0.
+    alphabet text DEFAULT '_-0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', -- The symbols used in the NanoId String. Must contain between 1 and 255 symbols.
+    additionalBytesFactor float DEFAULT 1.6 -- The additional bytes factor used for calculating the step size. Must be equal or greater then 1.
+)
+    RETURNS text -- A randomly generated NanoId String
+    LANGUAGE plpgsql
+    VOLATILE
+    LEAKPROOF
+    PARALLEL SAFE
+AS
+$$
+DECLARE
+    alphabetArray  text[];
+    alphabetLength int := 64;
+    mask           int := 63;
+    step           int := 34;
+BEGIN
+    IF size IS NULL OR size < 1 THEN
+        RAISE EXCEPTION 'The size must be defined and greater than 0!';
+    END IF;
+
+    IF alphabet IS NULL OR length(alphabet) = 0 OR length(alphabet) > 255 THEN
+        RAISE EXCEPTION 'The alphabet can''t be undefined, zero or bigger than 255 symbols!';
+    END IF;
+
+    IF additionalBytesFactor IS NULL OR additionalBytesFactor < 1 THEN
+        RAISE EXCEPTION 'The additional bytes factor can''t be less than 1!';
+    END IF;
+
+    alphabetArray := regexp_split_to_array(alphabet, '');
+    alphabetLength := array_length(alphabetArray, 1);
+    mask := (2 << cast(floor(log(alphabetLength - 1) / log(2)) as int)) - 1;
+    step := cast(ceil(additionalBytesFactor * mask * size / alphabetLength) AS int);
+
+    IF step > 1024 THEN
+        step := 1024; -- The step size % can''t be bigger then 1024!
+    END IF;
+
+    RETURN nanoid_optimized(size, alphabet, mask, step);
+END
+$$;
+
+-- Generates an optimized random string of a specified size using the given alphabet, mask, and step.
+-- This optimized version is designed for higher performance and lower memory overhead.
+-- No checks are performed! Use it only if you really know what you are doing.
+DROP FUNCTION IF EXISTS nanoid_optimized(int, text, int, int);
+CREATE OR REPLACE FUNCTION nanoid_optimized(
+    size int, -- The desired length of the generated string.
+    alphabet text, -- The set of characters to choose from for generating the string.
+    mask int, -- The mask used for mapping random bytes to alphabet indices. Should be `(2^n) - 1` where `n` is a power of 2 less than or equal to the alphabet size.
+    step int -- The number of random bytes to generate in each iteration. A larger value may speed up the function but increase memory usage.
+)
+    RETURNS text -- A randomly generated NanoId String
+    LANGUAGE plpgsql
+    VOLATILE
+    LEAKPROOF
+    PARALLEL SAFE
+AS
+$$
+DECLARE
+    idBuilder      text := '';
+    counter        int  := 0;
+    bytes          bytea;
+    alphabetIndex  int;
+    alphabetArray  text[];
+    alphabetLength int  := 64;
+BEGIN
+    alphabetArray := regexp_split_to_array(alphabet, '');
+    alphabetLength := array_length(alphabetArray, 1);
+
+    LOOP
+        bytes := gen_random_bytes(step);
+        FOR counter IN 0..step - 1
+            LOOP
+                alphabetIndex := (get_byte(bytes, counter) & mask) + 1;
+                IF alphabetIndex <= alphabetLength THEN
+                    idBuilder := idBuilder || alphabetArray[alphabetIndex];
+                    IF length(idBuilder) = size THEN
+                        RETURN idBuilder;
+                    END IF;
+                END IF;
+            END LOOP;
+    END LOOP;
+END
+$$;