sqlite: add limits property to DatabaseSync · nodejs/node@4c181e2

language features that allow ordinary SQL to deliberately corrupt the database file are disabled.

The defensive flag can also be set using `enableDefensive()`.

**Default:** `true`.

* `limits` {Object} Configuration for various SQLite limits. These limits

can be used to prevent excessive resource consumption when handling

potentially malicious input. See [Run-Time Limits][] and [Limit Constants][]

in the SQLite documentation for details. Default values are determined by

SQLite's compile-time defaults and may vary depending on how SQLite was

built. The following properties are supported:

* `length` {number} Maximum length of a string or BLOB.

* `sqlLength` {number} Maximum length of an SQL statement.

* `column` {number} Maximum number of columns.

* `exprDepth` {number} Maximum depth of an expression tree.

* `compoundSelect` {number} Maximum number of terms in a compound SELECT.

* `vdbeOp` {number} Maximum number of VDBE instructions.

* `functionArg` {number} Maximum number of function arguments.

* `attach` {number} Maximum number of attached databases.

* `likePatternLength` {number} Maximum length of a LIKE pattern.

* `variableNumber` {number} Maximum number of SQL variables.

* `triggerDepth` {number} Maximum trigger recursion depth.

Constructs a new `DatabaseSync` instance.

* Type: {boolean} Whether the database is currently within a transaction. This method

is a wrapper around [`sqlite3_get_autocommit()`][].

### `database.limits`

<!-- YAML

added: REPLACEME

-->

* Type: {Object}

An object for getting and setting SQLite database limits at runtime.

Each property corresponds to an SQLite limit and can be read or written.

```js

const db = new DatabaseSync(':memory:');

// Read current limit

console.log(db.limits.length);

// Set a new limit

db.limits.sqlLength = 100000;

// Reset a limit to its compile-time maximum

db.limits.sqlLength = Infinity;

```

Available properties: `length`, `sqlLength`, `column`, `exprDepth`,

`compoundSelect`, `vdbeOp`, `functionArg`, `attach`, `likePatternLength`,

`variableNumber`, `triggerDepth`.

Setting a property to `Infinity` resets the limit to its compile-time maximum value.

### `database.open()`

<!-- YAML

[Changesets and Patchsets]: https://www.sqlite.org/sessionintro.html#changesets_and_patchsets

[Constants Passed To The Conflict Handler]: https://www.sqlite.org/session/c_changeset_conflict.html

[Constants Returned From The Conflict Handler]: https://www.sqlite.org/session/c_changeset_abort.html

[Limit Constants]: https://www.sqlite.org/c3ref/c_limit_attached.html

[Run-Time Limits]: https://www.sqlite.org/c3ref/limit.html

[SQL injection]: https://en.wikipedia.org/wiki/SQL_injection

[Type conversion between JavaScript and SQLite]: #type-conversion-between-javascript-and-sqlite

[`ATTACH DATABASE`]: https://www.sqlite.org/lang_attach.html