зеркало из https://github.com/golang/pkgsite.git
65 строки
2.3 KiB
PL/PgSQL
65 строки
2.3 KiB
PL/PgSQL
-- Copyright 2020 The Go Authors. All rights reserved.
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-- Use of this source code is governed by a BSD-style
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-- license that can be found in the LICENSE file.
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BEGIN;
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-- Redefine the popular_search function, which is currently unused,
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-- to be the same as popular_search_go_mod but with a B weight of 1.
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CREATE OR REPLACE FUNCTION popular_search(rawquery text, lim integer, off integer, redist_factor real, go_mod_factor real) RETURNS SETOF search_result
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LANGUAGE plpgsql
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AS $$
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DECLARE cur CURSOR(query TSQUERY) FOR
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SELECT
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package_path,
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module_path,
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version,
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commit_time,
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imported_by_count,
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(
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-- default D, C, B, A weights are {0.1, 0.2, 0.4, 1.0}
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ts_rank('{0.1, 0.2, 1.0, 1.0}', tsv_search_tokens, query) *
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ln(exp(1)+imported_by_count) *
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CASE WHEN redistributable THEN 1 ELSE redist_factor END *
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CASE WHEN COALESCE(has_go_mod, true) THEN 1 ELSE go_mod_factor END *
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CASE WHEN tsv_search_tokens @@ query THEN 1 ELSE 0 END
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) score
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FROM search_documents
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ORDER BY imported_by_count DESC;
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top search_result[];
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res search_result;
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last_idx INT;
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BEGIN
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last_idx := lim+off;
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top := array_fill(NULL::search_result, array[last_idx]);
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OPEN cur(query := websearch_to_tsquery(rawquery));
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FETCH cur INTO res;
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WHILE found LOOP
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IF top[last_idx] IS NULL OR res.score >= top[last_idx].score THEN
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FOR i IN 1..last_idx LOOP
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IF top[i] IS NULL OR
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(res.score > top[i].score) OR
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(res.score = top[i].score AND res.commit_time > top[i].commit_time) OR
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(res.score = top[i].score AND res.commit_time = top[i].commit_time AND
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res.package_path < top[i].package_path) THEN
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top := (top[1:i-1] || res) || top[i:last_idx-1];
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EXIT;
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END IF;
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END LOOP;
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END IF;
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IF top[last_idx].score > ln(exp(1)+res.imported_by_count) THEN
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EXIT;
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END IF;
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FETCH cur INTO res;
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END LOOP;
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CLOSE cur;
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RETURN QUERY SELECT * FROM UNNEST(top[off+1:last_idx])
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WHERE package_path IS NOT NULL AND score > 0.1;
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END; $$;
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COMMENT ON FUNCTION popular_search(rawquery text, lim integer, off integer, redist_factor real, go_mod_factor real) IS
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'FUNCTION popular_search is used to generate results for search. It is implemented as a stored function, so that we can use a cursor to scan search documents procedurally, and stop scanning early, whenever our search results are provably correct.';
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END;
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