Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Optimize SQL rewriting by skipping unchanged AST nodes #30

Merged
merged 2 commits into from
May 9, 2024
Merged

Optimize SQL rewriting by skipping unchanged AST nodes #30

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
5a7f635
Optimize query rewrite
crisptrutski May 9, 2024
9e7838a
Neaten up
crisptrutski May 9, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
42 changes: 26 additions & 16 deletions src/macaw/rewrite.clj
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,14 +50,17 @@

(defn- update-query
"Emit a SQL string for an updated AST, preserving the comments and whitespace from the original SQL."
[updated-ast sql]
(let [replace-name (fn [->s]
(fn [acc ^ASTNodeAccess visitable _ctx]
(let [node (.getASTNode visitable)]
;; not sure why sometimes we get a phantom visitable without an underlying node
(if (nil? node)
acc
(conj acc [(node->idx-range node sql) (->s visitable)])))))]
[updated-ast updated-node? sql]
(let [replacement (fn [->text visitable]
(let [ast-node (.getASTNode ^ASTNodeAccess visitable)
idx-range (node->idx-range ast-node sql)
node-text (->text visitable)]
[idx-range node-text]))
replace-name (fn [->text]
(fn [acc visitable _ctx]
(cond-> acc
(updated-node? visitable)
(conj (replacement ->text visitable)))))]
(splice-replacements
sql
(mw/fold-query
Expand All @@ -67,21 +70,28 @@
[]))))

(defn- rename-table
[table-renames schema-renames ^Table table _ctx]
[updated-nodes table-renames schema-renames ^Table table _ctx]
(when-let [name' (get table-renames (.getName table))]
(vswap! updated-nodes conj table)
(.setName table name'))
(when-let [new-schema-name (get schema-renames (.getSchemaName table))]
(.setSchemaName table new-schema-name)))

(defn- rename-column
[updated-nodes column-renames ^Column column _ctx]
(when-let [name' (get column-renames (.getColumnName column))]
(vswap! updated-nodes conj column)
(.setColumnName column name')))

(defn replace-names
"Given a SQL query and its corresponding (untransformed) AST, apply the given table and column renames."
[sql parsed-ast {schema-renames :schemas
table-renames :tables
column-renames :columns}]
(-> parsed-ast
(mw/walk-query
{:table (partial rename-table table-renames schema-renames)
:column-qualifier (partial rename-table table-renames schema-renames)
:column (fn [^Column column _ctx] (when-let [name' (get column-renames (.getColumnName column))]
(.setColumnName column name')))})
(update-query sql)))
(let [updated-nodes (volatile! #{})]
(-> parsed-ast
(mw/walk-query
{:table (partial rename-table updated-nodes table-renames schema-renames)
:column-qualifier (partial rename-table updated-nodes table-renames schema-renames)
:column (partial rename-column updated-nodes column-renames)})
(update-query @updated-nodes sql))))
Loading