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GENERATE_RANJID_SQL

Constant GENERATE_RANJID_SQL 

Source
pub const GENERATE_RANJID_SQL: &str = "DO $install$\nDECLARE\n    _sch text := COALESCE(current_schema(), \'public\');\nBEGIN\n    EXECUTE format($sql$\nCREATE OR REPLACE FUNCTION generate_ranjids(\n    in_node_id INTEGER,\n    requested_count INTEGER,\n    allow_spanning BOOLEAN DEFAULT true\n)\nRETURNS TABLE(id UUID)\nLANGUAGE plpgsql\nSET search_path = %I, pg_catalog\nAS $func$\nDECLARE\n    epoch_us NUMERIC(30,0);\n    epoch_offset NUMERIC(30,0);\n    now_us NUMERIC(30,0);\n    last_time NUMERIC(30,0);\n    last_seq INTEGER;\n    current_tick NUMERIC(30,0);\n    next_seq INTEGER;\n    remaining INTEGER;\n    available_this_tick INTEGER;\n    emit_count INTEGER;\n    last_emitted_time NUMERIC(30,0);\n    last_emitted_seq INTEGER;\n    rollback_us NUMERIC(30,0);\n\n    ts_high BIGINT;\n    ts_mid BIGINT;\n    ts_low BIGINT;\n    hi BIGINT;\n    lo BIGINT;\n    precision_bits INTEGER := 0; -- microseconds (matches actual computation)\nBEGIN\n    IF requested_count IS NULL OR requested_count <= 0 THEN\n        RAISE EXCEPTION \'requested_count must be greater than zero\';\n    END IF;\n\n    IF in_node_id IS NULL OR in_node_id < 0 OR in_node_id > 32767 THEN\n        RAISE EXCEPTION \'node_id %% is out of range for RanjId (0..32767)\', in_node_id;\n    END IF;\n\n    IF NOT EXISTS (\n        SELECT 1 FROM heer_nodes WHERE node_id = in_node_id AND is_active = true\n    ) THEN\n        RAISE EXCEPTION \'node_id %% is not registered as an active Heer node\', in_node_id;\n    END IF;\n\n    SELECT FLOOR(EXTRACT(EPOCH FROM c.epoch) * 1000000)::NUMERIC(30,0),\n           c.ranj_epoch_offset\n    INTO epoch_us, epoch_offset\n    FROM heer_config AS c\n    WHERE c.id = 1;\n\n    IF epoch_us IS NULL THEN\n        RAISE EXCEPTION \'heer_config row id=1 must exist before generating IDs\';\n    END IF;\n\n    INSERT INTO heer_ranj_node_state (node_id)\n    VALUES (in_node_id)\n    ON CONFLICT (node_id) DO NOTHING;\n\n    SELECT s.last_id_time, s.last_sequence\n    INTO last_time, last_seq\n    FROM heer_ranj_node_state AS s\n    WHERE s.node_id = in_node_id\n    FOR UPDATE;\n\n    -- Calculate current time AFTER acquiring the lock to avoid false clock rollback\n    -- under concurrency (another thread may have advanced last_id_time while we waited)\n    -- current_tick = (now - epoch_timestamp) + ranj_epoch_offset\n    -- The offset extends the epoch beyond TIMESTAMP range (e.g. Big Bang).\n    -- When offset is 0 (default), this reduces to simple (now - epoch).\n    now_us := FLOOR(EXTRACT(EPOCH FROM clock_timestamp()) * 1000000)::NUMERIC(30,0)\n              - epoch_us\n              + epoch_offset;\n\n    rollback_us := last_time - now_us;\n    IF rollback_us > 0 THEN\n        IF rollback_us < 2000 THEN\n            RAISE EXCEPTION \'logical future drift for ranj node %% (%% us) \u{2014} likely batch-induced, check batch sizing\', in_node_id, rollback_us\n                USING ERRCODE = \'50021\';\n        ELSIF rollback_us < 50000 THEN\n            RAISE EXCEPTION \'clock rollback detected for ranj node %% (%% us)\', in_node_id, rollback_us\n                USING ERRCODE = \'50020\';\n        ELSE\n            RAISE EXCEPTION \'hard clock rollback detected for ranj node %% (%% us)\', in_node_id, rollback_us\n                USING ERRCODE = \'50022\';\n        END IF;\n    END IF;\n\n    current_tick := GREATEST(now_us, last_time);\n    next_seq := CASE\n        WHEN current_tick = last_time THEN last_seq + 1\n        ELSE 0\n    END;\n\n    available_this_tick := 65536 - next_seq;\n    IF NOT allow_spanning AND requested_count > available_this_tick THEN\n        RAISE EXCEPTION\n            \'requested %% IDs but only %% remain in microsecond %% for ranj node %%\',\n            requested_count,\n            available_this_tick,\n            current_tick,\n            in_node_id;\n    END IF;\n\n    remaining := requested_count;\n\n    WHILE remaining > 0 LOOP\n        available_this_tick := 65536 - next_seq;\n        emit_count := LEAST(remaining, available_this_tick);\n\n        IF current_tick > (2::NUMERIC ^ 89) - 1 THEN\n            RAISE EXCEPTION \'RanjId timestamp %% exceeds 89-bit range (2^89 - 1)\', current_tick\n                USING ERRCODE = \'50030\';\n        END IF;\n\n        -- Decompose the 89-bit NUMERIC timestamp using division/modulo\n        -- so we never truncate at BIGINT\'s 2^63 limit. Each component\n        -- fits safely in a BIGINT after extraction.\n        -- Full range: 2^89 microseconds \u{2248} 19.62 billion years.\n        ts_high := (floor(current_tick / (2::NUMERIC ^ 41)) %% (2::NUMERIC ^ 48))::BIGINT;\n        ts_mid  := (floor(current_tick / (2::NUMERIC ^ 29)) %% (2::NUMERIC ^ 12))::BIGINT;\n        ts_low  := (current_tick %% (2::NUMERIC ^ 29))::BIGINT;\n\n        hi := (ts_high << 16)\n            | (8::BIGINT << 12)\n            | ts_mid;\n\n        RETURN QUERY\n        SELECT (\n            lpad(to_hex(hi), 16, \'0\')\n            || lpad(to_hex(\n                ((-9223372036854775808)::BIGINT  -- 0x8000000000000000 (sets variant bit 1)\n                | (precision_bits::BIGINT << 60)\n                | (ts_low << 31)\n                | (in_node_id::BIGINT << 16)\n                | seq.s::BIGINT)\n            ), 16, \'0\')\n        )::UUID AS id\n        FROM generate_series(next_seq, next_seq + emit_count - 1) AS seq(s);\n\n        last_emitted_time := current_tick;\n        last_emitted_seq := next_seq + emit_count - 1;\n        remaining := remaining - emit_count;\n        current_tick := current_tick + 1;\n        next_seq := 0;\n    END LOOP;\n\n    UPDATE heer_ranj_node_state\n    SET last_id_time = last_emitted_time,\n        last_sequence = last_emitted_seq,\n        updated_at = CURRENT_TIMESTAMP\n    WHERE node_id = in_node_id;\nEND;\n$func$;\n$sql$, _sch);\nEND;\n$install$;\n\nCREATE OR REPLACE FUNCTION generate_ranjids(\n    requested_count INTEGER,\n    allow_spanning BOOLEAN\n)\nRETURNS TABLE(id UUID)\nLANGUAGE sql\nAS $$\n    SELECT id\n    FROM generate_ranjids(current_heer_ranj_node_id(), requested_count, allow_spanning);\n$$;\n\nCREATE OR REPLACE FUNCTION generate_ranjids(requested_count INTEGER)\nRETURNS TABLE(id UUID)\nLANGUAGE sql\nAS $$\n    SELECT id\n    FROM generate_ranjids(current_heer_ranj_node_id(), requested_count, true);\n$$;\n\nCREATE OR REPLACE FUNCTION generate_ranjid(in_node_id INTEGER)\nRETURNS UUID\nLANGUAGE sql\nAS $$\n    SELECT id\n    FROM generate_ranjids(in_node_id, 1, true);\n$$;\n\nCREATE OR REPLACE FUNCTION generate_ranjid()\nRETURNS UUID\nLANGUAGE sql\nAS $$\n    SELECT id\n    FROM generate_ranjids(current_heer_ranj_node_id(), 1, true);\n$$;\n";