- Rename Mastodon::TimestampIds into Mastodon::Snowflake for clarity
- Skip for statuses coming from inbox, aka delivered in real-time
- Skip for statuses that claim to be from the future
"code": "connection.execute(\" CREATE OR REPLACE FUNCTION timestamp_id(table_name text)\\n RETURNS bigint AS\\n $$\\n DECLARE\\n time_part bigint;\\n sequence_base bigint;\\n tail bigint;\\n BEGIN\\n time_part := (\\n -- Get the time in milliseconds\\n ((date_part('epoch', now()) * 1000))::bigint\\n -- And shift it over two bytes\\n << 16);\\n\\n sequence_base := (\\n 'x' ||\\n -- Take the first two bytes (four hex characters)\\n substr(\\n -- Of the MD5 hash of the data we documented\\n md5(table_name ||\\n '#{SecureRandom.hex(16)}' ||\\n time_part::text\\n ),\\n 1, 4\\n )\\n -- And turn it into a bigint\\n )::bit(16)::bigint;\\n\\n -- Finally, add our sequence number to our base, and chop\\n -- it to the last two bytes\\n tail := (\\n (sequence_base + nextval(table_name || '_id_seq'))\\n & 65535);\\n\\n -- Return the time part and the sequence part. OR appears\\n -- faster here than addition, but they're equivalent:\\n -- time_part has no trailing two bytes, and tail is only\\n -- the last two bytes.\\n RETURN time_part | tail;\\n END\\n $$ LANGUAGE plpgsql VOLATILE;\\n\")",
"code": "connection.execute(\" CREATE OR REPLACE FUNCTION timestamp_id(table_name text)\\n RETURNS bigint AS\\n $$\\n DECLARE\\n time_part bigint;\\n sequence_base bigint;\\n tail bigint;\\n BEGIN\\n time_part := (\\n -- Get the time in milliseconds\\n ((date_part('epoch', now()) * 1000))::bigint\\n -- And shift it over two bytes\\n << 16);\\n\\n sequence_base := (\\n 'x' ||\\n -- Take the first two bytes (four hex characters)\\n substr(\\n -- Of the MD5 hash of the data we documented\\n md5(table_name ||\\n '#{SecureRandom.hex(16)}' ||\\n time_part::text\\n ),\\n 1, 4\\n )\\n -- And turn it into a bigint\\n )::bit(16)::bigint;\\n\\n -- Finally, add our sequence number to our base, and chop\\n -- it to the last two bytes\\n tail := (\\n (sequence_base + nextval(table_name || '_id_seq'))\\n & 65535);\\n\\n -- Return the time part and the sequence part. OR appears\\n -- faster here than addition, but they're equivalent:\\n -- time_part has no trailing two bytes, and tail is only\\n -- the last two bytes.\\n RETURN time_part | tail;\\n END\\n $$ LANGUAGE plpgsql VOLATILE;\\n\")",
Eugen Rochko
7 years ago
committed by