@electric-sql/pglite/dist/live/index.cjs.map

PGlite is a WASM Postgres build packaged into a TypeScript client library that enables you to run Postgres in the browser, Node.js and Bun, with no need to install any other dependencies. It is only 3.7mb gzipped.

{"version":3,"sources":["../../src/live/index.ts","../../../pg-protocol/src/string-utils.ts","../../../pg-protocol/src/buffer-writer.ts","../../../pg-protocol/src/serializer.ts","../../../pg-protocol/src/buffer-reader.ts","../../../pg-protocol/src/parser.ts","../../src/types.ts","../../src/parse.ts","../../src/utils.ts"],"sourcesContent":["import type {\n  Extension,\n  PGliteInterface,\n  Results,\n  Transaction,\n} from '../interface'\nimport type {\n  LiveQueryOptions,\n  LiveIncrementalQueryOptions,\n  LiveChangesOptions,\n  LiveNamespace,\n  LiveQuery,\n  LiveChanges,\n  Change,\n  LiveQueryResults,\n} from './interface'\nimport { uuid, formatQuery, debounceMutex } from '../utils.js'\n\nexport type {\n  LiveNamespace,\n  LiveQuery,\n  LiveChanges,\n  Change,\n  LiveQueryResults,\n} from './interface.js'\n\nconst MAX_RETRIES = 5\n\nconst setup = async (pg: PGliteInterface, _emscriptenOpts: any) => {\n  // The notify triggers are only ever added and never removed\n  // Keep track of which triggers have been added to avoid adding them multiple times\n  const tableNotifyTriggersAdded = new Set<string>()\n\n  const namespaceObj: LiveNamespace = {\n    async query<T>(\n      query: string | LiveQueryOptions<T>,\n      params?: any[] | null,\n      callback?: (results: Results<T>) => void,\n    ) {\n      let signal: AbortSignal | undefined\n      let offset: number | undefined\n      let limit: number | undefined\n      if (typeof query !== 'string') {\n        signal = query.signal\n        params = query.params\n        callback = query.callback\n        offset = query.offset\n        limit = query.limit\n        query = query.query\n      }\n\n      // Offset and limit must be provided together\n      if ((offset === undefined) !== (limit === undefined)) {\n        throw new Error('offset and limit must be provided together')\n      }\n\n      const isWindowed = offset !== undefined && limit !== undefined\n      let totalCount: number | undefined = undefined\n\n      if (\n        isWindowed &&\n        (typeof offset !== 'number' ||\n          isNaN(offset) ||\n          typeof limit !== 'number' ||\n          isNaN(limit))\n      ) {\n        throw new Error('offset and limit must be numbers')\n      }\n\n      let callbacks: Array<(results: Results<T>) => void> = callback\n        ? [callback]\n        : []\n      const id = uuid().replace(/-/g, '')\n      let dead = false\n\n      let results: LiveQueryResults<T>\n      let tables: { table_name: string; schema_name: string }[]\n\n      let unsubList: Array<(tx?: Transaction) => Promise<void>>\n      const init = async () => {\n        await pg.transaction(async (tx) => {\n          // Create a temporary view with the query\n          const formattedQuery =\n            params && params.length > 0\n              ? await formatQuery(pg, query, params, tx)\n              : query\n          await tx.exec(\n            `CREATE OR REPLACE TEMP VIEW live_query_${id}_view AS ${formattedQuery}`,\n          )\n\n          // Get the tables used in the view and add triggers to notify when they change\n          tables = await getTablesForView(tx, `live_query_${id}_view`)\n          await addNotifyTriggersToTables(tx, tables, tableNotifyTriggersAdded)\n\n          if (isWindowed) {\n            await tx.exec(`\n              PREPARE live_query_${id}_get(int, int) AS\n              SELECT * FROM live_query_${id}_view\n              LIMIT $1 OFFSET $2;\n            `)\n            await tx.exec(`\n              PREPARE live_query_${id}_get_total_count AS\n              SELECT COUNT(*) FROM live_query_${id}_view;\n            `)\n            totalCount = (\n              await tx.query<{ count: number }>(\n                `EXECUTE live_query_${id}_get_total_count;`,\n              )\n            ).rows[0].count\n            results = {\n              ...(await tx.query<T>(\n                `EXECUTE live_query_${id}_get(${limit}, ${offset});`,\n              )),\n              offset,\n              limit,\n              totalCount,\n            }\n          } else {\n            await tx.exec(`\n              PREPARE live_query_${id}_get AS\n              SELECT * FROM live_query_${id}_view;\n            `)\n            results = await tx.query<T>(`EXECUTE live_query_${id}_get;`)\n          }\n          // Setup the listeners\n          unsubList = await Promise.all(\n            tables!.map((table) =>\n              tx.listen(\n                `\"table_change__${table.schema_name}__${table.table_name}\"`,\n                async () => {\n                  refresh()\n                },\n              ),\n            ),\n          )\n        })\n      }\n      await init()\n\n      // Function to refresh the query\n      const refresh = debounceMutex(\n        async ({\n          offset: newOffset,\n          limit: newLimit,\n        }: {\n          offset?: number\n          limit?: number\n        } = {}) => {\n          // We can optionally provide new offset and limit values to refresh with\n          if (\n            !isWindowed &&\n            (newOffset !== undefined || newLimit !== undefined)\n          ) {\n            throw new Error(\n              'offset and limit cannot be provided for non-windowed queries',\n            )\n          }\n          if (\n            (newOffset &&\n              (typeof newOffset !== 'number' || isNaN(newOffset))) ||\n            (newLimit && (typeof newLimit !== 'number' || isNaN(newLimit)))\n          ) {\n            throw new Error('offset and limit must be numbers')\n          }\n          offset = newOffset ?? offset\n          limit = newLimit ?? limit\n\n          const run = async (count = 0) => {\n            if (callbacks.length === 0) {\n              return\n            }\n            try {\n              if (isWindowed) {\n                // For a windowed query we defer the refresh of the total count until\n                // after we have returned the results with the old total count. This\n                // is due to a count(*) being a fairly slow query and we want to update\n                // the rows on screen as quickly as possible.\n                results = {\n                  ...(await pg.query<T>(\n                    `EXECUTE live_query_${id}_get(${limit}, ${offset});`,\n                  )),\n                  offset,\n                  limit,\n                  totalCount, // This is the old total count\n                }\n              } else {\n                results = await pg.query<T>(`EXECUTE live_query_${id}_get;`)\n              }\n            } catch (e) {\n              const msg = (e as Error).message\n              if (\n                msg.startsWith(`prepared statement \"live_query_${id}`) &&\n                msg.endsWith('does not exist')\n              ) {\n                // If the prepared statement does not exist, reset and try again\n                // This can happen if using the multi-tab worker\n                if (count > MAX_RETRIES) {\n                  throw e\n                }\n                await init()\n                run(count + 1)\n              } else {\n                throw e\n              }\n            }\n\n            runResultCallbacks(callbacks, results)\n\n            // Update the total count\n            // If the total count has changed, refresh the query\n            if (isWindowed) {\n              const newTotalCount = (\n                await pg.query<{ count: number }>(\n                  `EXECUTE live_query_${id}_get_total_count;`,\n                )\n              ).rows[0].count\n              if (newTotalCount !== totalCount) {\n                // The total count has changed, refresh the query\n                totalCount = newTotalCount\n                refresh()\n              }\n            }\n          }\n          await run()\n        },\n      )\n\n      // Function to subscribe to the query\n      const subscribe = (callback: (results: Results<T>) => void) => {\n        if (dead) {\n          throw new Error(\n            'Live query is no longer active and cannot be subscribed to',\n          )\n        }\n        callbacks.push(callback)\n      }\n\n      // Function to unsubscribe from the query\n      // If no function is provided, unsubscribe all callbacks\n      // If there are no callbacks, unsubscribe from the notify triggers\n      const unsubscribe = async (callback?: (results: Results<T>) => void) => {\n        if (callback) {\n          callbacks = callbacks.filter((callback) => callback !== callback)\n        } else {\n          callbacks = []\n        }\n        if (callbacks.length === 0 && !dead) {\n          dead = true\n          await pg.transaction(async (tx) => {\n            await Promise.all(unsubList.map((unsub) => unsub(tx)))\n            await tx.exec(`\n              DROP VIEW IF EXISTS live_query_${id}_view;\n              DEALLOCATE live_query_${id}_get;\n            `)\n          })\n        }\n      }\n\n      // If the signal has already been aborted, unsubscribe\n      if (signal?.aborted) {\n        await unsubscribe()\n      } else {\n        // Add an event listener to unsubscribe if the signal is aborted\n        signal?.addEventListener(\n          'abort',\n          () => {\n            unsubscribe()\n          },\n          { once: true },\n        )\n      }\n\n      // Run the callback with the initial results\n      runResultCallbacks(callbacks, results!)\n\n      // Return the initial results\n      return {\n        initialResults: results!,\n        subscribe,\n        unsubscribe,\n        refresh,\n      } satisfies LiveQuery<T>\n    },\n\n    async changes<T>(\n      query: string | LiveChangesOptions<T>,\n      params?: any[] | null,\n      key?: string,\n      callback?: (changes: Array<Change<T>>) => void,\n    ) {\n      let signal: AbortSignal | undefined\n      if (typeof query !== 'string') {\n        signal = query.signal\n        params = query.params\n        key = query.key\n        callback = query.callback\n        query = query.query\n      }\n      if (!key) {\n        throw new Error('key is required for changes queries')\n      }\n      let callbacks: Array<(changes: Array<Change<T>>) => void> = callback\n        ? [callback]\n        : []\n      const id = uuid().replace(/-/g, '')\n      let dead = false\n\n      let tables: { table_name: string; schema_name: string }[]\n      let stateSwitch: 1 | 2 = 1\n      let changes: Results<Change<T>>\n\n      let unsubList: Array<(tx?: Transaction) => Promise<void>>\n\n      const init = async () => {\n        await pg.transaction(async (tx) => {\n          // Create a temporary view with the query\n          const formattedQuery = await formatQuery(pg, query, params, tx)\n          await tx.query(\n            `CREATE OR REPLACE TEMP VIEW live_query_${id}_view AS ${formattedQuery}`,\n          )\n\n          // Get the tables used in the view and add triggers to notify when they change\n          tables = await getTablesForView(tx, `live_query_${id}_view`)\n          await addNotifyTriggersToTables(tx, tables, tableNotifyTriggersAdded)\n\n          // Get the columns of the view\n          const columns = [\n            ...(\n              await tx.query<any>(`\n                SELECT column_name, data_type, udt_name\n                FROM information_schema.columns \n                WHERE table_name = 'live_query_${id}_view'\n              `)\n            ).rows,\n            { column_name: '__after__', data_type: 'integer' },\n          ]\n\n          // Init state tables as empty temp table\n          await tx.exec(`\n            CREATE TEMP TABLE live_query_${id}_state1 (LIKE live_query_${id}_view INCLUDING ALL);\n            CREATE TEMP TABLE live_query_${id}_state2 (LIKE live_query_${id}_view INCLUDING ALL);\n          `)\n\n          // Create Diff views and prepared statements\n          for (const curr of [1, 2]) {\n            const prev = curr === 1 ? 2 : 1\n            await tx.exec(`\n              PREPARE live_query_${id}_diff${curr} AS\n              WITH\n                prev AS (SELECT LAG(\"${key}\") OVER () as __after__, * FROM live_query_${id}_state${prev}),\n                curr AS (SELECT LAG(\"${key}\") OVER () as __after__, * FROM live_query_${id}_state${curr}),\n                data_diff AS (\n                  -- INSERT operations: Include all columns\n                  SELECT \n                    'INSERT' AS __op__,\n                    ${columns\n                      .map(\n                        ({ column_name }) =>\n                          `curr.\"${column_name}\" AS \"${column_name}\"`,\n                      )\n                      .join(',\\n')},\n                    ARRAY[]::text[] AS __changed_columns__\n                  FROM curr\n                  LEFT JOIN prev ON curr.${key} = prev.${key}\n                  WHERE prev.${key} IS NULL\n                UNION ALL\n                  -- DELETE operations: Include only the primary key\n                  SELECT \n                    'DELETE' AS __op__,\n                    ${columns\n                      .map(({ column_name, data_type, udt_name }) => {\n                        if (column_name === key) {\n                          return `prev.\"${column_name}\" AS \"${column_name}\"`\n                        } else {\n                          return `NULL${data_type === 'USER-DEFINED' ? `::${udt_name}` : ``} AS \"${column_name}\"`\n                        }\n                      })\n                      .join(',\\n')},\n                      ARRAY[]::text[] AS __changed_columns__\n                  FROM prev\n                  LEFT JOIN curr ON prev.${key} = curr.${key}\n                  WHERE curr.${key} IS NULL\n                UNION ALL\n                  -- UPDATE operations: Include only changed columns\n                  SELECT \n                    'UPDATE' AS __op__,\n                    ${columns\n                      .map(({ column_name, data_type, udt_name }) =>\n                        column_name === key\n                          ? `curr.\"${column_name}\" AS \"${column_name}\"`\n                          : `CASE \n                              WHEN curr.\"${column_name}\" IS DISTINCT FROM prev.\"${column_name}\" \n                              THEN curr.\"${column_name}\"\n                              ELSE NULL${data_type === 'USER-DEFINED' ? `::${udt_name}` : ``}\n                              END AS \"${column_name}\"`,\n                      )\n                      .join(',\\n')},\n                      ARRAY(SELECT unnest FROM unnest(ARRAY[${columns\n                        .filter(({ column_name }) => column_name !== key)\n                        .map(\n                          ({ column_name }) =>\n                            `CASE\n                              WHEN curr.\"${column_name}\" IS DISTINCT FROM prev.\"${column_name}\" \n                              THEN '${column_name}' \n                              ELSE NULL \n                              END`,\n                        )\n                        .join(\n                          ', ',\n                        )}]) WHERE unnest IS NOT NULL) AS __changed_columns__\n                  FROM curr\n                  INNER JOIN prev ON curr.${key} = prev.${key}\n                  WHERE NOT (curr IS NOT DISTINCT FROM prev)\n                )\n              SELECT * FROM data_diff;\n            `)\n          }\n\n          // Setup the listeners\n          unsubList = await Promise.all(\n            tables!.map((table) =>\n              tx.listen(\n                `\"table_change__${table.schema_name}__${table.table_name}\"`,\n                async () => {\n                  refresh()\n                },\n              ),\n            ),\n          )\n        })\n      }\n\n      await init()\n\n      const refresh = debounceMutex(async () => {\n        if (callbacks.length === 0 && changes) {\n          return\n        }\n        let reset = false\n        for (let i = 0; i < 5; i++) {\n          try {\n            await pg.transaction(async (tx) => {\n              // Populate the state table\n              await tx.exec(`\n                INSERT INTO live_query_${id}_state${stateSwitch} \n                  SELECT * FROM live_query_${id}_view;\n              `)\n\n              // Get the changes\n              changes = await tx.query<any>(\n                `EXECUTE live_query_${id}_diff${stateSwitch};`,\n              )\n\n              // Switch state\n              stateSwitch = stateSwitch === 1 ? 2 : 1\n\n              // Truncate the old state table\n              await tx.exec(`\n                TRUNCATE live_query_${id}_state${stateSwitch};\n              `)\n            })\n            break\n          } catch (e) {\n            const msg = (e as Error).message\n            if (\n              msg ===\n              `relation \"live_query_${id}_state${stateSwitch}\" does not exist`\n            ) {\n              // If the state table does not exist, reset and try again\n              // This can happen if using the multi-tab worker\n              reset = true\n              await init()\n              continue\n            } else {\n              throw e\n            }\n          }\n        }\n\n        runChangeCallbacks(callbacks, [\n          ...(reset\n            ? [\n                {\n                  __op__: 'RESET' as const,\n                },\n              ]\n            : []),\n          ...changes!.rows,\n        ])\n      })\n\n      // Function to subscribe to the query\n      const subscribe = (callback: (changes: Array<Change<T>>) => void) => {\n        if (dead) {\n          throw new Error(\n            'Live query is no longer active and cannot be subscribed to',\n          )\n        }\n        callbacks.push(callback)\n      }\n\n      // Function to unsubscribe from the query\n      const unsubscribe = async (\n        callback?: (changes: Array<Change<T>>) => void,\n      ) => {\n        if (callback) {\n          callbacks = callbacks.filter((callback) => callback !== callback)\n        } else {\n          callbacks = []\n        }\n        if (callbacks.length === 0 && !dead) {\n          dead = true\n          await pg.transaction(async (tx) => {\n            await Promise.all(unsubList.map((unsub) => unsub(tx)))\n            await tx.exec(`\n              DROP VIEW IF EXISTS live_query_${id}_view;\n              DROP TABLE IF EXISTS live_query_${id}_state1;\n              DROP TABLE IF EXISTS live_query_${id}_state2;\n              DEALLOCATE live_query_${id}_diff1;\n              DEALLOCATE live_query_${id}_diff2;\n            `)\n          })\n        }\n      }\n\n      // If the signal has already been aborted, unsubscribe\n      if (signal?.aborted) {\n        await unsubscribe()\n      } else {\n        // Add an event listener to unsubscribe if the signal is aborted\n        signal?.addEventListener(\n          'abort',\n          () => {\n            unsubscribe()\n          },\n          { once: true },\n        )\n      }\n\n      // Run the callback with the initial changes\n      await refresh()\n\n      // Fields\n      const fields = changes!.fields.filter(\n        (field) =>\n          !['__after__', '__op__', '__changed_columns__'].includes(field.name),\n      )\n\n      // Return the initial results\n      return {\n        fields,\n        initialChanges: changes!.rows,\n        subscribe,\n        unsubscribe,\n        refresh,\n      } satisfies LiveChanges<T>\n    },\n\n    async incrementalQuery<T>(\n      query: string | LiveIncrementalQueryOptions<T>,\n      params?: any[] | null,\n      key?: string,\n      callback?: (results: Results<T>) => void,\n    ) {\n      let signal: AbortSignal | undefined\n      if (typeof query !== 'string') {\n        signal = query.signal\n        params = query.params\n        key = query.key\n        callback = query.callback\n        query = query.query\n      }\n      if (!key) {\n        throw new Error('key is required for incremental queries')\n      }\n      let callbacks: Array<(results: Results<T>) => void> = callback\n        ? [callback]\n        : []\n      const rowsMap: Map<any, any> = new Map()\n      const afterMap: Map<any, any> = new Map()\n      let lastRows: T[] = []\n      let firstRun = true\n\n      const {\n        fields,\n        unsubscribe: unsubscribeChanges,\n        refresh,\n      } = await namespaceObj.changes<T>(query, params, key, (changes) => {\n        // Process the changes\n        for (const change of changes) {\n          const {\n            __op__: op,\n            __changed_columns__: changedColumns,\n            ...obj\n          } = change as typeof change & { [key: string]: any }\n          switch (op) {\n            case 'RESET':\n              rowsMap.clear()\n              afterMap.clear()\n              break\n            case 'INSERT':\n              rowsMap.set(obj[key], obj)\n              afterMap.set(obj.__after__, obj[key])\n              break\n            case 'DELETE': {\n              const oldObj = rowsMap.get(obj[key])\n              rowsMap.delete(obj[key])\n              // null is the starting point, we don't delete it as another insert\n              // may have happened thats replacing it\n              if (oldObj.__after__ !== null) {\n                afterMap.delete(oldObj.__after__)\n              }\n              break\n            }\n            case 'UPDATE': {\n              const newObj = { ...(rowsMap.get(obj[key]) ?? {}) }\n              for (const columnName of changedColumns) {\n                newObj[columnName] = obj[columnName]\n                if (columnName === '__after__') {\n                  afterMap.set(obj.__after__, obj[key])\n                }\n              }\n              rowsMap.set(obj[key], newObj)\n              break\n            }\n          }\n        }\n\n        // Get the rows in order\n        const rows: T[] = []\n        let lastKey: any = null\n        for (let i = 0; i < rowsMap.size; i++) {\n          const nextKey = afterMap.get(lastKey)\n          const obj = rowsMap.get(nextKey)\n          if (!obj) {\n            break\n          }\n          // Remove the __after__ key from the exposed row\n          const cleanObj = { ...obj }\n          delete cleanObj.__after__\n          rows.push(cleanObj)\n          lastKey = nextKey\n        }\n        lastRows = rows\n\n        // Run the callbacks\n        if (!firstRun) {\n          runResultCallbacks(callbacks, {\n            rows,\n            fields,\n          })\n        }\n      })\n\n      firstRun = false\n      runResultCallbacks(callbacks, {\n        rows: lastRows,\n        fields,\n      })\n\n      const subscribe = (callback: (results: Results<T>) => void) => {\n        callbacks.push(callback)\n      }\n\n      const unsubscribe = async (callback?: (results: Results<T>) => void) => {\n        if (callback) {\n          callbacks = callbacks.filter((callback) => callback !== callback)\n        } else {\n          callbacks = []\n        }\n        if (callbacks.length === 0) {\n          await unsubscribeChanges()\n        }\n      }\n\n      if (signal?.aborted) {\n        await unsubscribe()\n      } else {\n        signal?.addEventListener(\n          'abort',\n          () => {\n            unsubscribe()\n          },\n          { once: true },\n        )\n      }\n\n      return {\n        initialResults: {\n          rows: lastRows,\n          fields,\n        },\n        subscribe,\n        unsubscribe,\n        refresh,\n      } satisfies LiveQuery<T>\n    },\n  }\n\n  return {\n    namespaceObj,\n  }\n}\n\nexport const live = {\n  name: 'Live Queries',\n  setup,\n} satisfies Extension\n\nexport type PGliteWithLive = PGliteInterface & {\n  live: LiveNamespace\n}\n\n/**\n * Get a list of all the tables used in a view, recursively\n * @param tx a transaction or PGlite instance\n * @param viewName the name of the view\n * @returns list of tables used in the view\n */\nasync function getTablesForView(\n  tx: Transaction | PGliteInterface,\n  viewName: string,\n): Promise<{ table_name: string; schema_name: string }[]> {\n  const result = await tx.query<{\n    table_name: string\n    schema_name: string\n  }>(\n    `\n      WITH RECURSIVE view_dependencies AS (\n        -- Base case: Get the initial view's dependencies\n        SELECT DISTINCT\n          cl.relname AS dependent_name,\n          n.nspname AS schema_name,\n          cl.relkind = 'v' AS is_view\n        FROM pg_rewrite r\n        JOIN pg_depend d ON r.oid = d.objid\n        JOIN pg_class cl ON d.refobjid = cl.oid\n        JOIN pg_namespace n ON cl.relnamespace = n.oid\n        WHERE\n          r.ev_class = (\n              SELECT oid FROM pg_class WHERE relname = $1 AND relkind = 'v'\n          )\n          AND d.deptype = 'n'\n\n        UNION ALL\n\n        -- Recursive case: Traverse dependencies for views\n        SELECT DISTINCT\n          cl.relname AS dependent_name,\n          n.nspname AS schema_name,\n          cl.relkind = 'v' AS is_view\n        FROM view_dependencies vd\n        JOIN pg_rewrite r ON vd.dependent_name = (\n          SELECT relname FROM pg_class WHERE oid = r.ev_class AND relkind = 'v'\n        )\n        JOIN pg_depend d ON r.oid = d.objid\n        JOIN pg_class cl ON d.refobjid = cl.oid\n        JOIN pg_namespace n ON cl.relnamespace = n.oid\n        WHERE d.deptype = 'n'\n      )\n      SELECT DISTINCT\n        dependent_name AS table_name,\n        schema_name\n      FROM view_dependencies\n      WHERE NOT is_view; -- Exclude intermediate views\n    `,\n    [viewName],\n  )\n\n  return result.rows.map((row) => ({\n    table_name: row.table_name,\n    schema_name: row.schema_name,\n  }))\n}\n\n/**\n * Add triggers to tables to notify when they change\n * @param tx a transaction or PGlite instance\n * @param tables list of tables to add triggers to\n */\nasync function addNotifyTriggersToTables(\n  tx: Transaction | PGliteInterface,\n  tables: { table_name: string; schema_name: string }[],\n  tableNotifyTriggersAdded: Set<string>,\n) {\n  const triggers = tables\n    .filter(\n      (table) =>\n        !tableNotifyTriggersAdded.has(\n          `${table.schema_name}_${table.table_name}`,\n        ),\n    )\n    .map((table) => {\n      return `\n      CREATE OR REPLACE FUNCTION \"_notify_${table.schema_name}_${table.table_name}\"() RETURNS TRIGGER AS $$\n      BEGIN\n        PERFORM pg_notify('table_change__${table.schema_name}__${table.table_name}', '');\n        RETURN NULL;\n      END;\n      $$ LANGUAGE plpgsql;\n      CREATE OR REPLACE TRIGGER \"_notify_trigger_${table.schema_name}_${table.table_name}\"\n      AFTER INSERT OR UPDATE OR DELETE ON \"${table.schema_name}\".\"${table.table_name}\"\n      FOR EACH STATEMENT EXECUTE FUNCTION \"_notify_${table.schema_name}_${table.table_name}\"();\n      `\n    })\n    .join('\\n')\n  if (triggers.trim() !== '') {\n    await tx.exec(triggers)\n  }\n  tables.map((table) =>\n    tableNotifyTriggersAdded.add(`${table.schema_name}_${table.table_name}`),\n  )\n}\n\nconst runResultCallbacks = <T>(\n  callbacks: Array<(results: Results<T>) => void>,\n  results: Results<T>,\n) => {\n  for (const callback of callbacks) {\n    callback(results)\n  }\n}\n\nconst runChangeCallbacks = <T>(\n  callbacks: Array<(changes: Array<Change<T>>) => void>,\n  changes: Array<Change<T>>,\n) => {\n  for (const callback of callbacks) {\n    callback(changes)\n  }\n}\n","/**\n * Calculates the byte length of a UTF-8 encoded string\n * Adapted from https://stackoverflow.com/a/23329386\n * @param str - UTF-8 encoded string\n * @returns byte length of string\n */\nfunction byteLengthUtf8(str: string): number {\n  let byteLength = str.length\n  for (let i = str.length - 1; i >= 0; i--) {\n    const code = str.charCodeAt(i)\n    if (code > 0x7f && code <= 0x7ff) byteLength++\n    else if (code > 0x7ff && code <= 0xffff) byteLength += 2\n    if (code >= 0xdc00 && code <= 0xdfff) i-- // trail surrogate\n  }\n  return byteLength\n}\n\nexport { byteLengthUtf8 }\n","import { byteLengthUtf8 } from './string-utils'\n\nexport class Writer {\n  #bufferView: DataView\n  #offset: number = 5\n\n  readonly #littleEndian = false as const\n  readonly #encoder = new TextEncoder()\n  readonly #headerPosition: number = 0\n  constructor(private size = 256) {\n    this.#bufferView = this.#allocateBuffer(size)\n  }\n\n  #allocateBuffer(size: number): DataView {\n    return new DataView(new ArrayBuffer(size))\n  }\n\n  #ensure(size: number): void {\n    const remaining = this.#bufferView.byteLength - this.#offset\n    if (remaining < size) {\n      const oldBuffer = this.#bufferView.buffer\n      // exponential growth factor of around ~ 1.5\n      // https://stackoverflow.com/questions/2269063/buffer-growth-strategy\n      const newSize = oldBuffer.byteLength + (oldBuffer.byteLength >> 1) + size\n      this.#bufferView = this.#allocateBuffer(newSize)\n      new Uint8Array(this.#bufferView.buffer).set(new Uint8Array(oldBuffer))\n    }\n  }\n\n  public addInt32(num: number): Writer {\n    this.#ensure(4)\n    this.#bufferView.setInt32(this.#offset, num, this.#littleEndian)\n    this.#offset += 4\n    return this\n  }\n\n  public addInt16(num: number): Writer {\n    this.#ensure(2)\n    this.#bufferView.setInt16(this.#offset, num, this.#littleEndian)\n    this.#offset += 2\n    return this\n  }\n\n  public addCString(string: string): Writer {\n    if (string) {\n      // TODO(msfstef): might be faster to extract `addString` code and\n      // ensure length + 1 once rather than length and then +1?\n      this.addString(string)\n    }\n\n    // set null terminator\n    this.#ensure(1)\n    this.#bufferView.setUint8(this.#offset, 0)\n    this.#offset++\n    return this\n  }\n\n  public addString(string: string = ''): Writer {\n    const length = byteLengthUtf8(string)\n    this.#ensure(length)\n    this.#encoder.encodeInto(\n      string,\n      new Uint8Array(this.#bufferView.buffer, this.#offset),\n    )\n    this.#offset += length\n    return this\n  }\n\n  public add(otherBuffer: ArrayBuffer): Writer {\n    this.#ensure(otherBuffer.byteLength)\n    new Uint8Array(this.#bufferView.buffer).set(\n      new Uint8Array(otherBuffer),\n      this.#offset,\n    )\n\n    this.#offset += otherBuffer.byteLength\n    return this\n  }\n\n  #join(code?: number): ArrayBuffer {\n    if (code) {\n      this.#bufferView.setUint8(this.#headerPosition, code)\n      // length is everything in this packet minus the code\n      const length = this.#offset - (this.#headerPosition + 1)\n      this.#bufferView.setInt32(\n        this.#headerPosition + 1,\n        length,\n        this.#littleEndian,\n      )\n    }\n    return this.#bufferView.buffer.slice(code ? 0 : 5, this.#offset)\n  }\n\n  public flush(code?: number): Uint8Array {\n    const result = this.#join(code)\n    this.#offset = 5\n    this.#bufferView = this.#allocateBuffer(this.size)\n    return new Uint8Array(result)\n  }\n}\n","import { Writer } from './buffer-writer'\nimport { byteLengthUtf8 } from './string-utils'\n\nconst enum code {\n  startup = 0x70,\n  query = 0x51,\n  parse = 0x50,\n  bind = 0x42,\n  execute = 0x45,\n  flush = 0x48,\n  sync = 0x53,\n  end = 0x58,\n  close = 0x43,\n  describe = 0x44,\n  copyFromChunk = 0x64,\n  copyDone = 0x63,\n  copyFail = 0x66,\n}\n\ntype LegalValue = string | ArrayBuffer | ArrayBufferView | null\n\nconst writer = new Writer()\n\nconst startup = (opts: Record<string, string>): Uint8Array => {\n  // protocol version\n  writer.addInt16(3).addInt16(0)\n  for (const key of Object.keys(opts)) {\n    writer.addCString(key).addCString(opts[key])\n  }\n\n  writer.addCString('client_encoding').addCString('UTF8')\n\n  const bodyBuffer = writer.addCString('').flush()\n  // this message is sent without a code\n\n  const length = bodyBuffer.byteLength + 4\n\n  return new Writer().addInt32(length).add(bodyBuffer).flush()\n}\n\nconst requestSsl = (): Uint8Array => {\n  const bufferView = new DataView(new ArrayBuffer(8))\n  bufferView.setInt32(0, 8, false)\n  bufferView.setInt32(4, 80877103, false)\n  return new Uint8Array(bufferView.buffer)\n}\n\nconst password = (password: string): Uint8Array => {\n  return writer.addCString(password).flush(code.startup)\n}\n\nconst sendSASLInitialResponseMessage = (\n  mechanism: string,\n  initialResponse: string,\n): Uint8Array => {\n  // 0x70 = 'p'\n  writer\n    .addCString(mechanism)\n    .addInt32(byteLengthUtf8(initialResponse))\n    .addString(initialResponse)\n\n  return writer.flush(code.startup)\n}\n\nconst sendSCRAMClientFinalMessage = (additionalData: string): Uint8Array => {\n  return writer.addString(additionalData).flush(code.startup)\n}\n\nconst query = (text: string): Uint8Array => {\n  return writer.addCString(text).flush(code.query)\n}\n\ntype ParseOpts = {\n  name?: string\n  types?: number[]\n  text: string\n}\n\nconst emptyValueArray: LegalValue[] = []\n\nconst parse = (query: ParseOpts): Uint8Array => {\n  // expect something like this:\n  // { name: 'queryName',\n  //   text: 'select * from blah',\n  //   types: ['int8', 'bool'] }\n\n  // normalize missing query names to allow for null\n  const name = query.name ?? ''\n  if (name.length > 63) {\n    /* eslint-disable no-console */\n    console.error(\n      'Warning! Postgres only supports 63 characters for query names.',\n    )\n    console.error('You supplied %s (%s)', name, name.length)\n    console.error(\n      'This can cause conflicts and silent errors executing queries',\n    )\n    /* eslint-enable no-console */\n  }\n\n  const buffer = writer\n    .addCString(name) // name of query\n    .addCString(query.text) // actual query text\n    .addInt16(query.types?.length ?? 0)\n\n  query.types?.forEach((type) => buffer.addInt32(type))\n\n  return writer.flush(code.parse)\n}\n\ntype ValueMapper = (param: unknown, index: number) => LegalValue\n\ntype BindOpts = {\n  portal?: string\n  binary?: boolean\n  statement?: string\n  values?: LegalValue[]\n  // optional map from JS value to postgres value per parameter\n  valueMapper?: ValueMapper\n}\n\nconst paramWriter = new Writer()\n\n// make this a const enum so typescript will inline the value\nconst enum ParamType {\n  STRING = 0,\n  BINARY = 1,\n}\n\nconst writeValues = (values: LegalValue[], valueMapper?: ValueMapper): void => {\n  for (let i = 0; i < values.length; i++) {\n    const mappedVal = valueMapper ? valueMapper(values[i], i) : values[i]\n    if (mappedVal === null) {\n      // add the param type (string) to the writer\n      writer.addInt16(ParamType.STRING)\n      // write -1 to the param writer to indicate null\n      paramWriter.addInt32(-1)\n    } else if (\n      mappedVal instanceof ArrayBuffer ||\n      ArrayBuffer.isView(mappedVal)\n    ) {\n      const buffer = ArrayBuffer.isView(mappedVal)\n        ? mappedVal.buffer.slice(\n            mappedVal.byteOffset,\n            mappedVal.byteOffset + mappedVal.byteLength,\n          )\n        : mappedVal\n      // add the param type (binary) to the writer\n      writer.addInt16(ParamType.BINARY)\n      // add the buffer to the param writer\n      paramWriter.addInt32(buffer.byteLength)\n      paramWriter.add(buffer)\n    } else {\n      // add the param type (string) to the writer\n      writer.addInt16(ParamType.STRING)\n      paramWriter.addInt32(byteLengthUtf8(mappedVal))\n      paramWriter.addString(mappedVal)\n    }\n  }\n}\n\nconst bind = (config: BindOpts = {}): Uint8Array => {\n  // normalize config\n  const portal = config.portal ?? ''\n  const statement = config.statement ?? ''\n  const binary = config.binary ?? false\n  const values = config.values ?? emptyValueArray\n  const len = values.length\n\n  writer.addCString(portal).addCString(statement)\n  writer.addInt16(len)\n\n  writeValues(values, config.valueMapper)\n\n  writer.addInt16(len)\n  writer.add(paramWriter.flush())\n\n  // format code\n  writer.addInt16(binary ? ParamType.BINARY : ParamType.STRING)\n  return writer.flush(code.bind)\n}\n\ntype ExecOpts = {\n  portal?: string\n  rows?: number\n}\n\nconst emptyExecute = new Uint8Array([\n  code.execute,\n  0x00,\n  0x00,\n  0x00,\n  0x09,\n  0x00,\n  0x00,\n  0x00,\n  0x00,\n  0x00,\n])\n\nconst execute = (config?: ExecOpts): Uint8Array => {\n  // this is the happy path for most queries\n  if (!config || (!config.portal && !config.rows)) {\n    return emptyExecute\n  }\n\n  const portal = config.portal ?? ''\n  const rows = config.rows ?? 0\n\n  const portalLength = byteLengthUtf8(portal)\n  const len = 4 + portalLength + 1 + 4\n  // one extra bit for code\n  const bufferView = new DataView(new ArrayBuffer(1 + len))\n  bufferView.setUint8(0, code.execute)\n  bufferView.setInt32(1, len, false)\n  new TextEncoder().encodeInto(portal, new Uint8Array(bufferView.buffer, 5))\n  bufferView.setUint8(portalLength + 5, 0) // null terminate portal cString\n  bufferView.setUint32(bufferView.byteLength - 4, rows, false)\n  return new Uint8Array(bufferView.buffer)\n}\n\nconst cancel = (processID: number, secretKey: number): Uint8Array => {\n  const bufferView = new DataView(new ArrayBuffer(16))\n  bufferView.setInt32(0, 16, false)\n  bufferView.setInt16(4, 1234, false)\n  bufferView.setInt16(6, 5678, false)\n  bufferView.setInt32(8, processID, false)\n  bufferView.setInt32(12, secretKey, false)\n  return new Uint8Array(bufferView.buffer)\n}\n\ntype PortalOpts = {\n  type: 'S' | 'P'\n  name?: string\n}\n\nconst cstringMessage = (code: code, string: string): Uint8Array => {\n  const writer = new Writer()\n  writer.addCString(string)\n  return writer.flush(code)\n}\n\nconst emptyDescribePortal = writer.addCString('P').flush(code.describe)\nconst emptyDescribeStatement = writer.addCString('S').flush(code.describe)\n\nconst describe = (msg: PortalOpts): Uint8Array => {\n  return msg.name\n    ? cstringMessage(code.describe, `${msg.type}${msg.name ?? ''}`)\n    : msg.type === 'P'\n      ? emptyDescribePortal\n      : emptyDescribeStatement\n}\n\nconst close = (msg: PortalOpts): Uint8Array => {\n  const text = `${msg.type}${msg.name ?? ''}`\n  return cstringMessage(code.close, text)\n}\n\nconst copyData = (chunk: ArrayBuffer): Uint8Array => {\n  return writer.add(chunk).flush(code.copyFromChunk)\n}\n\nconst copyFail = (message: string): Uint8Array => {\n  return cstringMessage(code.copyFail, message)\n}\n\nconst codeOnlyBuffer = (code: code): Uint8Array =>\n  new Uint8Array([code, 0x00, 0x00, 0x00, 0x04])\n\nconst flushBuffer = codeOnlyBuffer(code.flush)\nconst syncBuffer = codeOnlyBuffer(code.sync)\nconst endBuffer = codeOnlyBuffer(code.end)\nconst copyDoneBuffer = codeOnlyBuffer(code.copyDone)\n\nconst serialize = {\n  startup,\n  password,\n  requestSsl,\n  sendSASLInitialResponseMessage,\n  sendSCRAMClientFinalMessage,\n  query,\n  parse,\n  bind,\n  execute,\n  describe,\n  close,\n  flush: () => flushBuffer,\n  sync: () => syncBuffer,\n  end: () => endBuffer,\n  copyData,\n  copyDone: () => copyDoneBuffer,\n  copyFail,\n  cancel,\n}\n\nexport { serialize }\n","const emptyBuffer = new ArrayBuffer(0)\n\nexport class BufferReader {\n  #bufferView: DataView = new DataView(emptyBuffer)\n  #offset: number\n\n  // TODO(bmc): support non-utf8 encoding?\n  readonly #encoding: string = 'utf-8' as const\n  readonly #decoder = new TextDecoder(this.#encoding)\n  readonly #littleEndian: boolean = false as const\n\n  constructor(offset: number = 0) {\n    this.#offset = offset\n  }\n\n  public setBuffer(offset: number, buffer: ArrayBuffer): void {\n    this.#offset = offset\n    this.#bufferView = new DataView(buffer)\n  }\n\n  public int16(): number {\n    // const result = this.buffer.readInt16BE(this.#offset)\n    const result = this.#bufferView.getInt16(this.#offset, this.#littleEndian)\n    this.#offset += 2\n    return result\n  }\n\n  public byte(): number {\n    // const result = this.bufferView[this.#offset]\n    const result = this.#bufferView.getUint8(this.#offset)\n    this.#offset++\n    return result\n  }\n\n  public int32(): number {\n    // const result = this.buffer.readInt32BE(this.#offset)\n    const result = this.#bufferView.getInt32(this.#offset, this.#littleEndian)\n    this.#offset += 4\n    return result\n  }\n\n  public string(length: number): string {\n    // const result = this.#bufferView.toString(\n    //   this.#encoding,\n    //   this.#offset,\n    //   this.#offset + length,\n    // )\n    // this.#offset += length\n\n    const result = this.#decoder.decode(this.bytes(length))\n    return result\n  }\n\n  public cstring(): string {\n    // const start = this.#offset\n    // let end = start\n    // while (this.#bufferView[end++] !== 0) {}\n\n    const start = this.#offset\n    let end = start\n    while (this.#bufferView.getUint8(end++) !== 0) {\n      // no-op - increment until terminator reached\n    }\n    const result = this.string(end - start - 1)\n    this.#offset = end\n    return result\n  }\n\n  public bytes(length: number): Uint8Array {\n    // const result = this.buffer.slice(this.#offset, this.#offset + length)\n    const result = this.#bufferView.buffer.slice(\n      this.#offset,\n      this.#offset + length,\n    )\n    this.#offset += length\n    return new Uint8Array(result)\n  }\n}\n","import {\n  bindComplete,\n  parseComplete,\n  closeComplete,\n  noData,\n  portalSuspended,\n  copyDone,\n  replicationStart,\n  emptyQuery,\n  ReadyForQueryMessage,\n  CommandCompleteMessage,\n  CopyDataMessage,\n  CopyResponse,\n  NotificationResponseMessage,\n  RowDescriptionMessage,\n  ParameterDescriptionMessage,\n  Field,\n  DataRowMessage,\n  ParameterStatusMessage,\n  BackendKeyDataMessage,\n  DatabaseError,\n  BackendMessage,\n  MessageName,\n  NoticeMessage,\n  AuthenticationMessage,\n  AuthenticationOk,\n  AuthenticationCleartextPassword,\n  AuthenticationMD5Password,\n  AuthenticationSASL,\n  AuthenticationSASLContinue,\n  AuthenticationSASLFinal,\n} from './messages'\nimport { BufferParameter, Modes } from './types'\nimport { BufferReader } from './buffer-reader'\n\n// every message is prefixed with a single bye\nconst CODE_LENGTH = 1 as const\n// every message has an int32 length which includes itself but does\n// NOT include the code in the length\nconst LEN_LENGTH = 4 as const\n\nconst HEADER_LENGTH = CODE_LENGTH + LEN_LENGTH\n\nexport type Packet = {\n  code: number\n  packet: ArrayBuffer\n}\n\nconst emptyBuffer = new ArrayBuffer(0)\n\nconst enum MessageCodes {\n  DataRow = 0x44, // D\n  ParseComplete = 0x31, // 1\n  BindComplete = 0x32, // 2\n  CloseComplete = 0x33, // 3\n  CommandComplete = 0x43, // C\n  ReadyForQuery = 0x5a, // Z\n  NoData = 0x6e, // n\n  NotificationResponse = 0x41, // A\n  AuthenticationResponse = 0x52, // R\n  ParameterStatus = 0x53, // S\n  BackendKeyData = 0x4b, // K\n  ErrorMessage = 0x45, // E\n  NoticeMessage = 0x4e, // N\n  RowDescriptionMessage = 0x54, // T\n  ParameterDescriptionMessage = 0x74, // t\n  PortalSuspended = 0x73, // s\n  ReplicationStart = 0x57, // W\n  EmptyQuery = 0x49, // I\n  CopyIn = 0x47, // G\n  CopyOut = 0x48, // H\n  CopyDone = 0x63, // c\n  CopyData = 0x64, // d\n}\n\nexport type MessageCallback = (msg: BackendMessage) => void\n\nexport class Parser {\n  #bufferView: DataView = new DataView(emptyBuffer)\n  #bufferRemainingLength: number = 0\n  #bufferOffset: number = 0\n  #reader = new BufferReader()\n\n  public parse(buffer: BufferParameter, callback: MessageCallback) {\n    this.#mergeBuffer(\n      ArrayBuffer.isView(buffer)\n        ? buffer.buffer.slice(\n            buffer.byteOffset,\n            buffer.byteOffset + buffer.byteLength,\n          )\n        : buffer,\n    )\n    const bufferFullLength = this.#bufferOffset + this.#bufferRemainingLength\n    let offset = this.#bufferOffset\n    while (offset + HEADER_LENGTH <= bufferFullLength) {\n      // code is 1 byte long - it identifies the message type\n      const code = this.#bufferView.getUint8(offset)\n      // length is 1 Uint32BE - it is the length of the message EXCLUDING the code\n      const length = this.#bufferView.getUint32(offset + CODE_LENGTH, false)\n      const fullMessageLength = CODE_LENGTH + length\n      if (fullMessageLength + offset <= bufferFullLength) {\n        const message = this.#handlePacket(\n          offset + HEADER_LENGTH,\n          code,\n          length,\n          this.#bufferView.buffer,\n        )\n        callback(message)\n        offset += fullMessageLength\n      } else {\n        break\n      }\n    }\n    if (offset === bufferFullLength) {\n      // No more use for the buffer\n      this.#bufferView = new DataView(emptyBuffer)\n      this.#bufferRemainingLength = 0\n      this.#bufferOffset = 0\n    } else {\n      // Adjust the cursors of remainingBuffer\n      this.#bufferRemainingLength = bufferFullLength - offset\n      this.#bufferOffset = offset\n    }\n  }\n\n  #mergeBuffer(buffer: ArrayBuffer): void {\n    if (this.#bufferRemainingLength > 0) {\n      const newLength = this.#bufferRemainingLength + buffer.byteLength\n      const newFullLength = newLength + this.#bufferOffset\n      if (newFullLength > this.#bufferView.byteLength) {\n        // We can't concat the new buffer with the remaining one\n        let newBuffer: ArrayBuffer\n        if (\n          newLength <= this.#bufferView.byteLength &&\n          this.#bufferOffset >= this.#bufferRemainingLength\n        ) {\n          // We can move the relevant part to the beginning of the buffer instead of allocating a new buffer\n          newBuffer = this.#bufferView.buffer\n        } else {\n          // Allocate a new larger buffer\n          let newBufferLength = this.#bufferView.byteLength * 2\n          while (newLength >= newBufferLength) {\n            newBufferLength *= 2\n          }\n          newBuffer = new ArrayBuffer(newBufferLength)\n        }\n        // Move the remaining buffer to the new one\n        new Uint8Array(newBuffer).set(\n          new Uint8Array(\n            this.#bufferView.buffer,\n            this.#bufferOffset,\n            this.#bufferRemainingLength,\n          ),\n        )\n        this.#bufferView = new DataView(newBuffer)\n        this.#bufferOffset = 0\n      }\n\n      // Concat the new buffer with the remaining one\n      new Uint8Array(this.#bufferView.buffer).set(\n        new Uint8Array(buffer),\n        this.#bufferOffset + this.#bufferRemainingLength,\n      )\n      this.#bufferRemainingLength = newLength\n    } else {\n      this.#bufferView = new DataView(buffer)\n      this.#bufferOffset = 0\n      this.#bufferRemainingLength = buffer.byteLength\n    }\n  }\n\n  #handlePacket(\n    offset: number,\n    code: number,\n    length: number,\n    bytes: ArrayBuffer,\n  ): BackendMessage {\n    switch (code) {\n      case MessageCodes.BindComplete:\n        return bindComplete\n      case MessageCodes.ParseComplete:\n        return parseComplete\n      case MessageCodes.CloseComplete:\n        return closeComplete\n      case MessageCodes.NoData:\n        return noData\n      case MessageCodes.PortalSuspended:\n        return portalSuspended\n      case MessageCodes.CopyDone:\n        return copyDone\n      case MessageCodes.ReplicationStart:\n        return replicationStart\n      case MessageCodes.EmptyQuery:\n        return emptyQuery\n      case MessageCodes.DataRow:\n        return this.#parseDataRowMessage(offset, length, bytes)\n      case MessageCodes.CommandComplete:\n        return this.#parseCommandCompleteMessage(offset, length, bytes)\n      case MessageCodes.ReadyForQuery:\n        return this.#parseReadyForQueryMessage(offset, length, bytes)\n      case MessageCodes.NotificationResponse:\n        return this.#parseNotificationMessage(offset, length, bytes)\n      case MessageCodes.AuthenticationResponse:\n        return this.#parseAuthenticationResponse(offset, length, bytes)\n      case MessageCodes.ParameterStatus:\n        return this.#parseParameterStatusMessage(offset, length, bytes)\n      case MessageCodes.BackendKeyData:\n        return this.#parseBackendKeyData(offset, length, bytes)\n      case MessageCodes.ErrorMessage:\n        return this.#parseErrorMessage(offset, length, bytes, 'error')\n      case MessageCodes.NoticeMessage:\n        return this.#parseErrorMessage(offset, length, bytes, 'notice')\n      case MessageCodes.RowDescriptionMessage:\n        return this.#parseRowDescriptionMessage(offset, length, bytes)\n      case MessageCodes.ParameterDescriptionMessage:\n        return this.#parseParameterDescriptionMessage(offset, length, bytes)\n      case MessageCodes.CopyIn:\n        return this.#parseCopyInMessage(offset, length, bytes)\n      case MessageCodes.CopyOut:\n        return this.#parseCopyOutMessage(offset, length, bytes)\n      case MessageCodes.CopyData:\n        return this.#parseCopyData(offset, length, bytes)\n      default:\n        return new DatabaseError(\n          'received invalid response: ' + code.toString(16),\n          length,\n          'error',\n        )\n    }\n  }\n\n  #parseReadyForQueryMessage(\n    offset: number,\n    length: number,\n    bytes: ArrayBuffer,\n  ) {\n    this.#reader.setBuffer(offset, bytes)\n    const status = this.#reader.string(1)\n    return new ReadyForQueryMessage(length, status)\n  }\n\n  #parseCommandCompleteMessage(\n    offset: number,\n    length: number,\n    bytes: ArrayBuffer,\n  ) {\n    this.#reader.setBuffer(offset, bytes)\n    const text = this.#reader.cstring()\n    return new CommandCompleteMessage(length, text)\n  }\n\n  #parseCopyData(offset: number, length: number, bytes: ArrayBuffer) {\n    const chunk = bytes.slice(offset, offset + (length - 4))\n    return new CopyDataMessage(length, new Uint8Array(chunk))\n  }\n\n  #parseCopyInMessage(offset: number, length: number, bytes: ArrayBuffer) {\n    return this.#parseCopyMessage(offset, length, bytes, 'copyInResponse')\n  }\n\n  #parseCopyOutMessage(offset: num