76 lines
2.6 KiB
JavaScript
76 lines
2.6 KiB
JavaScript
'use strict';
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const { cppdb } = require('../util');
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const controllers = new WeakMap();
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module.exports = function transaction(fn) {
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if (typeof fn !== 'function') throw new TypeError('Expected first argument to be a function');
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const db = this[cppdb];
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const controller = getController(db, this);
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const { apply } = Function.prototype;
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// Each version of the transaction function has these same properties
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const properties = {
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default: { value: wrapTransaction(apply, fn, db, controller.default) },
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deferred: { value: wrapTransaction(apply, fn, db, controller.deferred) },
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immediate: { value: wrapTransaction(apply, fn, db, controller.immediate) },
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exclusive: { value: wrapTransaction(apply, fn, db, controller.exclusive) },
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database: { value: this, enumerable: true },
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};
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Object.defineProperties(properties.default.value, properties);
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Object.defineProperties(properties.deferred.value, properties);
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Object.defineProperties(properties.immediate.value, properties);
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Object.defineProperties(properties.exclusive.value, properties);
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// Return the default version of the transaction function
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return properties.default.value;
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};
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// Return the database's cached transaction controller, or create a new one
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const getController = (db, self) => {
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let controller = controllers.get(db);
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if (!controller) {
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const shared = {
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commit: db.prepare('COMMIT', self, false),
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rollback: db.prepare('ROLLBACK', self, false),
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savepoint: db.prepare('SAVEPOINT `\t_bs3.\t`', self, false),
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release: db.prepare('RELEASE `\t_bs3.\t`', self, false),
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rollbackTo: db.prepare('ROLLBACK TO `\t_bs3.\t`', self, false),
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};
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controllers.set(db, controller = {
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default: Object.assign({ begin: db.prepare('BEGIN', self, false) }, shared),
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deferred: Object.assign({ begin: db.prepare('BEGIN DEFERRED', self, false) }, shared),
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immediate: Object.assign({ begin: db.prepare('BEGIN IMMEDIATE', self, false) }, shared),
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exclusive: Object.assign({ begin: db.prepare('BEGIN EXCLUSIVE', self, false) }, shared),
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});
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}
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return controller;
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};
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// Return a new transaction function by wrapping the given function
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const wrapTransaction = (apply, fn, db, { begin, commit, rollback, savepoint, release, rollbackTo }) => function sqliteTransaction() {
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let before, after, undo;
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if (db.inTransaction) {
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before = savepoint;
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after = release;
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undo = rollbackTo;
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} else {
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before = begin;
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after = commit;
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undo = rollback;
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}
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before.run();
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try {
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const result = apply.call(fn, this, arguments);
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after.run();
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return result;
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} catch (ex) {
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if (db.inTransaction) {
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undo.run();
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if (undo !== rollback) after.run();
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}
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throw ex;
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}
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};
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