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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at
http://mozilla.org/MPL/2.0/. */
/**
* PRIVACY WARNING
* ===============
*
* Database file names can be exposed through telemetry and in crash reports on
* the
https://crash-stats.mozilla.org site, to allow recognizing the affected
* database.
* if your database name may contain privacy sensitive information, e.g. an
* URL origin, you should use openDatabaseWithFileURL and pass an explicit
* TelemetryFilename to it. That name will be used both for telemetry and for
* thread names in crash reports.
* If you have different needs (e.g. using the javascript module or an async
* connection from the main thread) please coordinate with the mozStorage peers.
*/
import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
import { setTimeout } from "resource://gre/modules/Timer.sys.mjs";
const lazy = {};
ChromeUtils.defineESModuleGetters(
lazy,
{
AsyncShutdown: "resource://gre/modules/AsyncShutdown.sys.mjs",
FileUtils: "resource://gre/modules/FileUtils.sys.mjs",
},
{ global: "contextual" }
);
XPCOMUtils.defineLazyServiceGetter(
lazy,
"FinalizationWitnessService",
"@mozilla.org/toolkit/finalizationwitness;1",
"nsIFinalizationWitnessService"
);
// Regular expression used by isInvalidBoundLikeQuery
var likeSqlRegex = /\bLIKE\b\s(?![@:?])/i;
// Counts the number of created connections per database basename(). This is
// used for logging to distinguish connection instances.
var connectionCounters = new Map();
// Tracks identifiers of wrapped connections, that are Storage connections
// opened through mozStorage and then wrapped by Sqlite.sys.mjs to use its syntactic
// sugar API. Since these connections have an unknown origin, we use this set
// to differentiate their behavior.
var wrappedConnections = new Set();
/**
* Once `true`, reject any attempt to open or close a database.
*/
function isClosed() {
// If Barriers have not been initialized yet, just trust AppStartup.
if (
typeof Object.getOwnPropertyDescriptor(lazy, "Barriers").get == "function"
) {
// It's still possible to open new connections at profile-before-change, so
// use the next phase here, as a fallback.
return Services.startup.isInOrBeyondShutdownPhase(
Ci.nsIAppStartup.SHUTDOWN_PHASE_XPCOMWILLSHUTDOWN
);
}
return lazy.Barriers.shutdown.client.isClosed;
}
var Debugging = {
// Tests should fail if a connection auto closes. The exception is
// when finalization itself is tested, in which case this flag
// should be set to false.
failTestsOnAutoClose: true,
};
/**
* Helper function to check whether LIKE is implemented using proper bindings.
*
* @param sql
* (string) The SQL query to be verified.
* @return boolean value telling us whether query was correct or not
*/
function isInvalidBoundLikeQuery(sql) {
return likeSqlRegex.test(sql);
}
// Displays a script error message
function logScriptError(message) {
let consoleMessage = Cc["@mozilla.org/scripterror;1"].createInstance(
Ci.nsIScriptError
);
let stack = new Error();
consoleMessage.init(
message,
stack.fileName,
stack.lineNumber,
0,
Ci.nsIScriptError.errorFlag,
"component javascript"
);
Services.console.logMessage(consoleMessage);
// This `Promise.reject` will cause tests to fail. The debugging
// flag can be used to suppress this for tests that explicitly
// test auto closes.
if (Debugging.failTestsOnAutoClose) {
Promise.reject(new Error(message));
}
}
/**
* Gets connection identifier from its database file name.
*
* @param fileName
* A database file string name.
* @return the connection identifier.
*/
function getIdentifierByFileName(fileName) {
let number = connectionCounters.get(fileName) || 0;
connectionCounters.set(fileName, number + 1);
return fileName + "#" + number;
}
/**
* Convert mozIStorageError to common NS_ERROR_*
* The conversion is mostly based on the one in
* mozStoragePrivateHelpers::ConvertResultCode, plus a few additions.
*
* @param {integer} result a mozIStorageError result code.
* @returns {integer} an NS_ERROR_* result code.
*/
function convertStorageErrorResult(result) {
switch (result) {
case Ci.mozIStorageError.PERM:
case Ci.mozIStorageError.AUTH:
case Ci.mozIStorageError.CANTOPEN:
return Cr.NS_ERROR_FILE_ACCESS_DENIED;
case Ci.mozIStorageError.LOCKED:
return Cr.NS_ERROR_FILE_IS_LOCKED;
case Ci.mozIStorageError.READONLY:
return Cr.NS_ERROR_FILE_READ_ONLY;
case Ci.mozIStorageError.ABORT:
case Ci.mozIStorageError.INTERRUPT:
return Cr.NS_ERROR_ABORT;
case Ci.mozIStorageError.TOOBIG:
case Ci.mozIStorageError.FULL:
return Cr.NS_ERROR_FILE_NO_DEVICE_SPACE;
case Ci.mozIStorageError.NOMEM:
return Cr.NS_ERROR_OUT_OF_MEMORY;
case Ci.mozIStorageError.BUSY:
return Cr.NS_ERROR_STORAGE_BUSY;
case Ci.mozIStorageError.CONSTRAINT:
return Cr.NS_ERROR_STORAGE_CONSTRAINT;
case Ci.mozIStorageError.NOLFS:
case Ci.mozIStorageError.IOERR:
return Cr.NS_ERROR_STORAGE_IOERR;
case Ci.mozIStorageError.SCHEMA:
case Ci.mozIStorageError.MISMATCH:
case Ci.mozIStorageError.MISUSE:
case Ci.mozIStorageError.RANGE:
return Ci.NS_ERROR_UNEXPECTED;
case Ci.mozIStorageError.CORRUPT:
case Ci.mozIStorageError.EMPTY:
case Ci.mozIStorageError.FORMAT:
case Ci.mozIStorageError.NOTADB:
return Cr.NS_ERROR_FILE_CORRUPTED;
default:
return Cr.NS_ERROR_FAILURE;
}
}
/**
* Barriers used to ensure that Sqlite.sys.mjs is shutdown after all
* its clients.
*/
ChromeUtils.defineLazyGetter(lazy, "Barriers", () => {
let Barriers = {
/**
* Public barrier that clients may use to add blockers to the
* shutdown of Sqlite.sys.mjs. Triggered by profile-before-change.
* Once all blockers of this barrier are lifted, we close the
* ability to open new connections.
*/
shutdown: new lazy.AsyncShutdown.Barrier(
"Sqlite.sys.mjs: wait until all clients have completed their task"
),
/**
* Private barrier blocked by connections that are still open.
* Triggered after Barriers.shutdown is lifted and `isClosed()` returns
* `true`.
*/
connections: new lazy.AsyncShutdown.Barrier(
"Sqlite.sys.mjs: wait until all connections are closed"
),
};
/**
* Observer for the event which is broadcasted when the finalization
* witness `_witness` of `OpenedConnection` is garbage collected.
*
* The observer is passed the connection identifier of the database
* connection that is being finalized.
*/
let finalizationObserver = function (subject, topic, identifier) {
let connectionData = ConnectionData.byId.get(identifier);
if (connectionData === undefined) {
logScriptError(
"Error: Attempt to finalize unknown Sqlite connection: " +
identifier +
"\n"
);
return;
}
ConnectionData.byId.delete(identifier);
logScriptError(
"Warning: Sqlite connection '" +
identifier +
"' was not properly closed. Auto-close triggered by garbage collection.\n"
);
connectionData.close();
};
Services.obs.addObserver(finalizationObserver, "sqlite-finalization-witness");
/**
* Ensure that Sqlite.sys.mjs:
* - informs its clients before shutting down;
* - lets clients open connections during shutdown, if necessary;
* - waits for all connections to be closed before shutdown.
*/
lazy.AsyncShutdown.profileBeforeChange.addBlocker(
"Sqlite.sys.mjs shutdown blocker",
async function () {
await Barriers.shutdown.wait();
// At this stage, all clients have had a chance to open (and close)
// their databases. Some previous close operations may still be pending,
// so we need to wait until they are complete before proceeding.
await Barriers.connections.wait();
// Everything closed, no finalization events to catch
Services.obs.removeObserver(
finalizationObserver,
"sqlite-finalization-witness"
);
},
function status() {
if (isClosed()) {
// We are waiting for the connections to close. The interesting
// status is therefore the list of connections still pending.
return {
description: "Waiting for connections to close",
state: Barriers.connections.state,
};
}
// We are still in the first stage: waiting for the barrier
// to be lifted. The interesting status is therefore that of
// the barrier.
return {
description: "Waiting for the barrier to be lifted",
state: Barriers.shutdown.state,
};
}
);
return Barriers;
});
const VACUUM_CATEGORY = "vacuum-participant";
const VACUUM_CONTRACTID = "@sqlite.module.js/vacuum-participant;";
var registeredVacuumParticipants = new Map();
function registerVacuumParticipant(connectionData) {
let contractId = VACUUM_CONTRACTID + connectionData._identifier;
let factory = {
createInstance(iid) {
return connectionData.QueryInterface(iid);
},
QueryInterface: ChromeUtils.generateQI(["nsIFactory"]),
};
let cid = Services.uuid.generateUUID();
Components.manager
.QueryInterface(Ci.nsIComponentRegistrar)
.registerFactory(cid, contractId, contractId, factory);
Services.catMan.addCategoryEntry(
VACUUM_CATEGORY,
contractId,
contractId,
false,
false
);
registeredVacuumParticipants.set(contractId, { cid, factory });
}
function unregisterVacuumParticipant(connectionData) {
let contractId = VACUUM_CONTRACTID + connectionData._identifier;
let component = registeredVacuumParticipants.get(contractId);
if (component) {
Components.manager
.QueryInterface(Ci.nsIComponentRegistrar)
.unregisterFactory(component.cid, component.factory);
Services.catMan.deleteCategoryEntry(VACUUM_CATEGORY, contractId, false);
}
}
/**
* Create a ConsoleInstance logger with a given prefix.
* @param {string} prefix The prefix to use when logging.
* @returns {ConsoleInstance} a console logger.
*/
function createLoggerWithPrefix(prefix) {
return console.createInstance({
prefix: `SQLite JSM (${prefix})`,
maxLogLevelPref: "toolkit.sqlitejsm.loglevel",
});
}
/**
* Connection data with methods necessary for closing the connection.
*
* To support auto-closing in the event of garbage collection, this
* data structure contains all the connection data of an opened
* connection and all of the methods needed for sucessfully closing
* it.
*
* By putting this information in its own separate object, it is
* possible to store an additional reference to it without preventing
* a garbage collection of a finalization witness in
* OpenedConnection. When the witness detects a garbage collection,
* this object can be used to close the connection.
*
* This object contains more methods than just `close`. When
* OpenedConnection needs to use the methods in this object, it will
* dispatch its method calls here.
*/
function ConnectionData(connection, identifier, options = {}) {
this._logger = createLoggerWithPrefix(`Connection ${identifier}`);
this._logger.debug("Opened");
this._dbConn = connection;
// This is a unique identifier for the connection, generated through
// getIdentifierByFileName. It may be used for logging or as a key in Maps.
this._identifier = identifier;
this._open = true;
this._cachedStatements = new Map();
this._anonymousStatements = new Map();
this._anonymousCounter = 0;
// A map from statement index to mozIStoragePendingStatement, to allow for
// canceling prior to finalizing the mozIStorageStatements.
this._pendingStatements = new Map();
// Increments for each executed statement for the life of the connection.
this._statementCounter = 0;
// Increments whenever we request a unique operation id.
this._operationsCounter = 0;
if ("defaultTransactionType" in options) {
this.defaultTransactionType = options.defaultTransactionType;
} else {
this.defaultTransactionType = convertStorageTransactionType(
this._dbConn.defaultTransactionType
);
}
// Tracks whether this instance initiated a transaction.
this._initiatedTransaction = false;
// Manages a chain of transactions promises, so that new transactions
// always happen in queue to the previous ones. It never rejects.
this._transactionQueue = Promise.resolve();
this._idleShrinkMS = options.shrinkMemoryOnConnectionIdleMS;
if (this._idleShrinkMS) {
this._idleShrinkTimer = Cc["@mozilla.org/timer;1"].createInstance(
Ci.nsITimer
);
// We wait for the first statement execute to start the timer because
// shrinking now would not do anything.
}
// Deferred whose promise is resolved when the connection closing procedure
// is complete.
this._deferredClose = Promise.withResolvers();
this._closeRequested = false;
// An AsyncShutdown barrier used to make sure that we wait until clients
// are done before shutting down the connection.
this._barrier = new lazy.AsyncShutdown.Barrier(
`${this._identifier}: waiting for clients`
);
lazy.Barriers.connections.client.addBlocker(
this._identifier + ": waiting for shutdown",
this._deferredClose.promise,
() => ({
identifier: this._identifier,
isCloseRequested: this._closeRequested,
hasDbConn: !!this._dbConn,
initiatedTransaction: this._initiatedTransaction,
pendingStatements: this._pendingStatements.size,
statementCounter: this._statementCounter,
})
);
// We avoid creating a timer for every transaction, because in most cases they
// are not canceled and they are only used as a timeout.
// Instead the timer is reused when it's sufficiently close to the previous
// creation time (see `_getTimeoutPromise` for more info).
this._timeoutPromise = null;
// The last timestamp when we should consider using `this._timeoutPromise`.
this._timeoutPromiseExpires = 0;
this._useIncrementalVacuum = !!options.incrementalVacuum;
if (this._useIncrementalVacuum) {
this._logger.debug("Set auto_vacuum INCREMENTAL");
this.execute("PRAGMA auto_vacuum = 2").catch(ex => {
this._logger.error("Setting auto_vacuum to INCREMENTAL failed.");
console.error(ex);
});
}
this._expectedPageSize = options.pageSize ?? 0;
if (this._expectedPageSize) {
this._logger.debug("Set page_size to " + this._expectedPageSize);
this.execute("PRAGMA page_size = " + this._expectedPageSize).catch(ex => {
this._logger.error(
`Setting page_size to ${this._expectedPageSize} failed.`
);
console.error(ex);
});
}
this._vacuumOnIdle = options.vacuumOnIdle;
if (this._vacuumOnIdle) {
this._logger.debug("Register as vacuum participant");
this.QueryInterface = ChromeUtils.generateQI([
Ci.mozIStorageVacuumParticipant,
]);
registerVacuumParticipant(this);
}
}
/**
* Map of connection identifiers to ConnectionData objects
*
* The connection identifier is a human-readable name of the
* database. Used by finalization witnesses to be able to close opened
* connections on garbage collection.
*
* Key: _identifier of ConnectionData
* Value: ConnectionData object
*/
ConnectionData.byId = new Map();
ConnectionData.prototype = Object.freeze({
get expectedDatabasePageSize() {
return this._expectedPageSize;
},
get useIncrementalVacuum() {
return this._useIncrementalVacuum;
},
/**
* This should only be used by the VacuumManager component.
* @see unsafeRawConnection for an official (but still unsafe) API.
*/
get databaseConnection() {
if (this._vacuumOnIdle) {
return this._dbConn;
}
return null;
},
onBeginVacuum() {
let granted = !this.transactionInProgress;
this._logger.debug("Begin Vacuum - " + granted ? "granted" : "denied");
return granted;
},
onEndVacuum(succeeded) {
this._logger.debug("End Vacuum - " + succeeded ? "success" : "failure");
},
/**
* Run a task, ensuring that its execution will not be interrupted by shutdown.
*
* As the operations of this module are asynchronous, a sequence of operations,
* or even an individual operation, can still be pending when the process shuts
* down. If any of this operations is a write, this can cause data loss, simply
* because the write has not been completed (or even started) by shutdown.
*
* To avoid this risk, clients are encouraged to use `executeBeforeShutdown` for
* any write operation, as follows:
*
* myConnection.executeBeforeShutdown("Bookmarks: Removing a bookmark",
* async function(db) {
* // The connection will not be closed and shutdown will not proceed
* // until this task has completed.
*
* // `db` exposes the same API as `myConnection` but provides additional
* // logging support to help debug hard-to-catch shutdown timeouts.
*
* await db.execute(...);
* }));
*
* @param {string} name A human-readable name for the ongoing operation, used
* for logging and debugging purposes.
* @param {function(db)} task A function that takes as argument a Sqlite.sys.mjs
* db and returns a Promise.
*/
executeBeforeShutdown(parent, name, task) {
if (!name) {
throw new TypeError("Expected a human-readable name as first argument");
}
if (typeof task != "function") {
throw new TypeError("Expected a function as second argument");
}
if (this._closeRequested) {
throw new Error(
`${this._identifier}: cannot execute operation ${name}, the connection is already closing
`
);
}
// Status, used for AsyncShutdown crash reports.
let status = {
// The latest command started by `task`, either as a
// sql string, or as one of "<not started>" or "<closing>".
command: "<not started>",
// `true` if `command` was started but not completed yet.
isPending: false,
};
// An object with the same API as `this` but with
// additional logging. To keep logging simple, we
// assume that `task` is not running several queries
// concurrently.
let loggedDb = Object.create(parent, {
execute: {
value: async (sql, ...rest) => {
status.isPending = true;
status.command = sql;
try {
return await this.execute(sql, ...rest);
} finally {
status.isPending = false;
}
},
},
close: {
value: async () => {
status.isPending = true;
status.command = "<close>";
try {
return await this.close();
} finally {
status.isPending = false;
}
},
},
executeCached: {
value: async (sql, ...rest) => {
status.isPending = true;
status.command = "cached: " + sql;
try {
return await this.executeCached(sql, ...rest);
} finally {
status.isPending = false;
}
},
},
});
let promiseResult = task(loggedDb);
if (
!promiseResult ||
typeof promiseResult != "object" ||
!("then" in promiseResult)
) {
throw new TypeError("Expected a Promise");
}
let key = `${this._identifier}: ${name} (${this._getOperationId()})`;
let promiseComplete = promiseResult.catch(() => {});
this._barrier.client.addBlocker(key, promiseComplete, {
fetchState: () => status,
});
return (async () => {
try {
return await promiseResult;
} finally {
this._barrier.client.removeBlocker(key, promiseComplete);
}
})();
},
close() {
this._closeRequested = true;
if (!this._dbConn) {
return this._deferredClose.promise;
}
this._logger.debug("Request to close connection.");
this._clearIdleShrinkTimer();
if (this._vacuumOnIdle) {
this._logger.debug("Unregister as vacuum participant");
unregisterVacuumParticipant(this);
}
return this._barrier.wait().then(() => {
if (!this._dbConn) {
return undefined;
}
return this._finalize();
});
},
clone(readOnly = false) {
this.ensureOpen();
this._logger.debug("Request to clone connection.");
let options = {
connection: this._dbConn,
readOnly,
};
if (this._idleShrinkMS) {
options.shrinkMemoryOnConnectionIdleMS = this._idleShrinkMS;
}
return cloneStorageConnection(options);
},
_getOperationId() {
return this._operationsCounter++;
},
_finalize() {
this._logger.debug("Finalizing connection.");
// Cancel any pending statements.
for (let [, /* k */ statement] of this._pendingStatements) {
statement.cancel();
}
this._pendingStatements.clear();
// We no longer need to track these.
this._statementCounter = 0;
// Next we finalize all active statements.
for (let [, /* k */ statement] of this._anonymousStatements) {
statement.finalize();
}
this._anonymousStatements.clear();
for (let [, /* k */ statement] of this._cachedStatements) {
statement.finalize();
}
this._cachedStatements.clear();
// This guards against operations performed between the call to this
// function and asyncClose() finishing. See also bug 726990.
this._open = false;
// We must always close the connection at the Sqlite.sys.mjs-level, not
// necessarily at the mozStorage-level.
let markAsClosed = () => {
this._logger.debug("Closed");
// Now that the connection is closed, no need to keep
// a blocker for Barriers.connections.
lazy.Barriers.connections.client.removeBlocker(
this._deferredClose.promise
);
this._deferredClose.resolve();
};
if (wrappedConnections.has(this._identifier)) {
wrappedConnections.delete(this._identifier);
this._dbConn = null;
markAsClosed();
} else {
this._logger.debug("Calling asyncClose().");
try {
this._dbConn.asyncClose(markAsClosed);
} catch (ex) {
// If for any reason asyncClose fails, we must still remove the
// shutdown blockers and resolve _deferredClose.
markAsClosed();
} finally {
this._dbConn = null;
}
}
return this._deferredClose.promise;
},
executeCached(sql, params = null, onRow = null) {
this.ensureOpen();
if (!sql) {
throw new Error("sql argument is empty.");
}
let statement = this._cachedStatements.get(sql);
if (!statement) {
statement = this._dbConn.createAsyncStatement(sql);
this._cachedStatements.set(sql, statement);
}
this._clearIdleShrinkTimer();
return new Promise((resolve, reject) => {
try {
this._executeStatement(sql, statement, params, onRow).then(
result => {
this._startIdleShrinkTimer();
resolve(result);
},
error => {
this._startIdleShrinkTimer();
reject(error);
}
);
} catch (ex) {
this._startIdleShrinkTimer();
throw ex;
}
});
},
execute(sql, params = null, onRow = null) {
if (typeof sql != "string") {
throw new Error("Must define SQL to execute as a string: " + sql);
}
this.ensureOpen();
let statement = this._dbConn.createAsyncStatement(sql);
let index = this._anonymousCounter++;
this._anonymousStatements.set(index, statement);
this._clearIdleShrinkTimer();
let onFinished = () => {
this._anonymousStatements.delete(index);
statement.finalize();
this._startIdleShrinkTimer();
};
return new Promise((resolve, reject) => {
try {
this._executeStatement(sql, statement, params, onRow).then(
rows => {
onFinished();
resolve(rows);
},
error => {
onFinished();
reject(error);
}
);
} catch (ex) {
onFinished();
throw ex;
}
});
},
get transactionInProgress() {
return this._open && this._dbConn.transactionInProgress;
},
executeTransaction(func, type) {
// Identify the caller for debugging purposes.
let caller = new Error().stack
.split("\n", 3)
.pop()
.match(/^([^@]*@).*\/([^\/:]+)[:0-9]*$/);
caller = caller[1] + caller[2];
this._logger.debug(`Transaction (type ${type}) requested by: ${caller}`);
if (type == OpenedConnection.prototype.TRANSACTION_DEFAULT) {
type = this.defaultTransactionType;
} else if (!OpenedConnection.TRANSACTION_TYPES.includes(type)) {
throw new Error("Unknown transaction type: " + type);
}
this.ensureOpen();
// If a transaction yields on a never resolved promise, or is mistakenly
// nested, it could hang the transactions queue forever. Thus we timeout
// the execution after a meaningful amount of time, to ensure in any case
// we'll proceed after a while.
let timeoutPromise = this._getTimeoutPromise();
let promise = this._transactionQueue.then(() => {
if (this._closeRequested) {
throw new Error("Transaction canceled due to a closed connection.");
}
let transactionPromise = (async () => {
// At this point we should never have an in progress transaction, since
// they are enqueued.
if (this._initiatedTransaction) {
this._logger.error(
"Unexpected transaction in progress when trying to start a new one."
);
}
try {
// We catch errors in statement execution to detect nested transactions.
try {
await this.execute("BEGIN " + type + " TRANSACTION");
this._logger.debug(`Begin transaction`);
this._initiatedTransaction = true;
} catch (ex) {
// Unfortunately, if we are wrapping an existing connection, a
// transaction could have been started by a client of the same
// connection that doesn't use Sqlite.sys.mjs (e.g. C++ consumer).
// The best we can do is proceed without a transaction and hope
// things won't break.
if (wrappedConnections.has(this._identifier)) {
this._logger.warn(
"A new transaction could not be started cause the wrapped connection had one in progress",
ex
);
} else {
this._logger.warn(
"A transaction was already in progress, likely a nested transaction",
ex
);
throw ex;
}
}
let result;
try {
result = await Promise.race([func(), timeoutPromise]);
} catch (ex) {
// It's possible that the exception has been caused by trying to
// close the connection in the middle of a transaction.
if (this._closeRequested) {
this._logger.warn(
"Connection closed while performing a transaction",
ex
);
} else {
// Otherwise the function didn't resolve before the timeout, or
// generated an unexpected error. Then we rollback.
if (ex.becauseTimedOut) {
let caller_module = caller.split(":", 1)[0];
Glean.mozstorage.sqlitejsmTransactionTimeout[caller_module].add(
1
);
this._logger.error(
`The transaction requested by ${caller} timed out. Rolling back`,
ex
);
} else {
this._logger.error(
`Error during transaction requested by ${caller}. Rolling back`,
ex
);
}
// If we began a transaction, we must rollback it.
if (this._initiatedTransaction) {
try {
await this.execute("ROLLBACK TRANSACTION");
this._initiatedTransaction = false;
this._logger.debug(`Roll back transaction`);
} catch (inner) {
this._logger.error("Could not roll back transaction", inner);
}
}
}
// Rethrow the exception.
throw ex;
}
// See comment above about connection being closed during transaction.
if (this._closeRequested) {
this._logger.warn(
"Connection closed before committing the transaction."
);
throw new Error(
"Connection closed before committing the transaction."
);
}
// If we began a transaction, we must commit it.
if (this._initiatedTransaction) {
try {
await this.execute("COMMIT TRANSACTION");
this._logger.debug(`Commit transaction`);
} catch (ex) {
this._logger.warn("Error committing transaction", ex);
throw ex;
}
}
return result;
} finally {
this._initiatedTransaction = false;
}
})();
return Promise.race([transactionPromise, timeoutPromise]);
});
// Atomically update the queue before anyone else has a chance to enqueue
// further transactions.
this._transactionQueue = promise.catch(ex => {
this._logger.error(ex);
});
// Make sure that we do not shutdown the connection during a transaction.
this._barrier.client.addBlocker(
`Transaction (${this._getOperationId()})`,
this._transactionQueue
);
return promise;
},
shrinkMemory() {
this._logger.debug("Shrinking memory usage.");
return this.execute("PRAGMA shrink_memory").finally(() => {
this._clearIdleShrinkTimer();
});
},
discardCachedStatements() {
let count = 0;
for (let [, /* k */ statement] of this._cachedStatements) {
++count;
statement.finalize();
}
this._cachedStatements.clear();
this._logger.debug("Discarded " + count + " cached statements.");
return count;
},
interrupt() {
this._logger.debug("Trying to interrupt.");
this.ensureOpen();
this._dbConn.interrupt();
},
/**
* Helper method to bind parameters of various kinds through
* reflection.
*/
_bindParameters(statement, params) {
if (!params) {
return;
}
function bindParam(obj, key, val) {
let isBlob =
val &&
typeof val == "object" &&
["Uint8Array", "Uint8ClampedArray"].includes(val.constructor.name);
let args = [key, val];
if (isBlob) {
args.push(val.length);
}
let methodName = `bind${isBlob ? "Blob" : ""}By${
typeof key == "number" ? "Index" : "Name"
}`;
obj[methodName](...args);
}
if (Array.isArray(params)) {
// It's an array of separate params.
if (params.length && typeof params[0] == "object" && params[0] !== null) {
let paramsArray = statement.newBindingParamsArray();
for (let p of params) {
let bindings = paramsArray.newBindingParams();
for (let [key, value] of Object.entries(p)) {
bindParam(bindings, key, value);
}
paramsArray.addParams(bindings);
}
statement.bindParameters(paramsArray);
return;
}
// Indexed params.
for (let i = 0; i < params.length; i++) {
bindParam(statement, i, params[i]);
}
return;
}
// Named params.
if (params && typeof params == "object") {
for (let k in params) {
bindParam(statement, k, params[k]);
}
return;
}
throw new Error(
"Invalid type for bound parameters. Expected Array or " +
"object. Got: " +
params
);
},
_executeStatement(sql, statement, params, onRow) {
if (statement.state != statement.MOZ_STORAGE_STATEMENT_READY) {
throw new Error("Statement is not ready for execution.");
}
if (onRow && typeof onRow != "function") {
throw new Error("onRow must be a function. Got: " + onRow);
}
this._bindParameters(statement, params);
let index = this._statementCounter++;
let deferred = Promise.withResolvers();
let userCancelled = false;
let errors = [];
let rows = [];
let handledRow = false;
// Don't incur overhead for serializing params unless the messages go
// somewhere.
if (this._logger.shouldLog("Trace")) {
let msg = "Stmt #" + index + " " + sql;
if (params) {
msg += " - " + JSON.stringify(params);
}
this._logger.trace(msg);
} else {
this._logger.debug("Stmt #" + index + " starting");
}
let self = this;
let pending = statement.executeAsync({
handleResult(resultSet) {
// .cancel() may not be immediate and handleResult() could be called
// after a .cancel().
for (
let row = resultSet.getNextRow();
row && !userCancelled;
row = resultSet.getNextRow()
) {
if (!onRow) {
rows.push(row);
continue;
}
handledRow = true;
try {
onRow(row, () => {
userCancelled = true;
pending.cancel();
});
} catch (e) {
self._logger.warn("Exception when calling onRow callback", e);
}
}
},
handleError(error) {
self._logger.warn(
"Error when executing SQL (" + error.result + "): " + error.message
);
errors.push(error);
},
handleCompletion(reason) {
self._logger.debug("Stmt #" + index + " finished.");
self._pendingStatements.delete(index);
switch (reason) {
case Ci.mozIStorageStatementCallback.REASON_FINISHED:
case Ci.mozIStorageStatementCallback.REASON_CANCELED: {
// If there is an onRow handler, we always instead resolve to a
// boolean indicating whether the onRow handler was called or not.
let result = onRow ? handledRow : rows;
deferred.resolve(result);
break;
}
case Ci.mozIStorageStatementCallback.REASON_ERROR: {
let error = new Error(
"Error(s) encountered during statement execution: " +
errors.map(e => e.message).join(", ")
);
error.errors = errors;
// Forward the error result.
// Corruption is the most critical one so it's handled apart.
if (errors.some(e => e.result == Ci.mozIStorageError.CORRUPT)) {
error.result = Cr.NS_ERROR_FILE_CORRUPTED;
} else {
// Just use the first error result in the other cases.
error.result = convertStorageErrorResult(errors[0]?.result);
}
deferred.reject(error);
break;
}
default:
deferred.reject(
new Error("Unknown completion reason code: " + reason)
);
break;
}
},
});
this._pendingStatements.set(index, pending);
return deferred.promise;
},
ensureOpen() {
if (!this._open) {
throw new Error("Connection is not open.");
}
},
_clearIdleShrinkTimer() {
if (!this._idleShrinkTimer) {
return;
}
this._idleShrinkTimer.cancel();
},
_startIdleShrinkTimer() {
if (!this._idleShrinkTimer) {
return;
}
this._idleShrinkTimer.initWithCallback(
this.shrinkMemory.bind(this),
this._idleShrinkMS,
this._idleShrinkTimer.TYPE_ONE_SHOT
);
},
/**
* Returns a promise that will resolve after a time comprised between 80% of
* `TRANSACTIONS_TIMEOUT_MS` and `TRANSACTIONS_TIMEOUT_MS`. Use
* this method instead of creating several individual timers that may survive
* longer than necessary.
*/
_getTimeoutPromise() {
if (this._timeoutPromise && Cu.now() <= this._timeoutPromiseExpires) {
return this._timeoutPromise;
}
let timeoutPromise = new Promise((resolve, reject) => {
setTimeout(() => {
// Clear out this._timeoutPromise if it hasn't changed since we set it.
if (this._timeoutPromise == timeoutPromise) {
this._timeoutPromise = null;
}
let e = new Error(
"Transaction timeout, most likely caused by unresolved pending work."
);
e.becauseTimedOut = true;
reject(e);
}, Sqlite.TRANSACTIONS_TIMEOUT_MS);
});
this._timeoutPromise = timeoutPromise;
this._timeoutPromiseExpires =
Cu.now() + Sqlite.TRANSACTIONS_TIMEOUT_MS * 0.2;
return this._timeoutPromise;
},
/**
* Asynchronously makes a copy of the SQLite database while there may still be
* open connections on it.
*
* @param {string} destFilePath
* The path on the local filesystem to write the database copy. Any existing
* file at this path will be overwritten.
* @param {number} [pagesPerStep=0]
* The number of pages to copy per step. If not supplied or is 0, falls back
* to the platform default which is currently 5.
* @param {number} [stepDelayMs=0]
* The number of milliseconds to wait between copying step. If not supplied
* or is 0, falls back to the platform default which is currently 250.
* @return Promise<undefined, nsresult>
*/
async backupToFile(destFilePath, pagesPerStep = 0, stepDelayMs = 0) {
if (!this._dbConn) {
return Promise.reject(
new Error("No opened database connection to create a backup from.")
);
}
let destFile = await IOUtils.getFile(destFilePath);
return new Promise((resolve, reject) => {
this._dbConn.backupToFileAsync(
destFile,
result => {
if (Components.isSuccessCode(result)) {
resolve();
} else {
reject(result);
}
},
pagesPerStep,
stepDelayMs
);
});
},
});
/**
* Opens a connection to a SQLite database.
*
* The following parameters can control the connection:
*
* path -- (string) The filesystem path of the database file to open. If the
* file does not exist, a new database will be created.
*
* sharedMemoryCache -- (bool) Whether multiple connections to the database
* share the same memory cache. Sharing the memory cache likely results
* in less memory utilization. However, sharing also requires connections
* to obtain a lock, possibly making database access slower. Defaults to
* true.
*
* shrinkMemoryOnConnectionIdleMS -- (integer) If defined, the connection
* will attempt to minimize its memory usage after this many
* milliseconds of connection idle. The connection is idle when no
* statements are executing. There is no default value which means no
* automatic memory minimization will occur. Please note that this is
* *not* a timer on the idle service and this could fire while the
* application is active.
*
* readOnly -- (bool) Whether to open the database with SQLITE_OPEN_READONLY
* set. If used, writing to the database will fail. Defaults to false.
*
* ignoreLockingMode -- (bool) Whether to ignore locks on the database held
* by other connections. If used, implies readOnly. Defaults to false.
* USE WITH EXTREME CAUTION. This mode WILL produce incorrect results or
* return "false positive" corruption errors if other connections write
* to the DB at the same time.
*
* openNotExclusive -- (bool) Whether to open the database without an exclusive
* lock so the database can be accessed from multiple processes.
*
* vacuumOnIdle -- (bool) Whether to register this connection to be vacuumed
* on idle by the VacuumManager component.
* If you're vacuum-ing an incremental vacuum database, ensure to also
* set incrementalVacuum to true, otherwise this will try to change it
* to full vacuum mode.
*
* incrementalVacuum -- (bool) if set to true auto_vacuum = INCREMENTAL will
* be enabled for the database.
* Changing auto vacuum of an already populated database requires a full
* VACUUM. You can evaluate to enable vacuumOnIdle for that.
*
* pageSize -- (integer) This allows to set a custom page size for the
* database. It is usually not necessary to set it, since the default
* value should be good for most consumers.
* Changing the page size of an already populated database requires a full
* VACUUM. You can evaluate to enable vacuumOnIdle for that.
*
* testDelayedOpenPromise -- (promise) Used by tests to delay the open
* callback handling and execute code between asyncOpen and its callback.
*
* extensions -- (array) Array of SQLite extension names that should be
* loaded for the connection. List of approved extensions is hardcoded in
* `mozStorageConnection`, no other extensions can be loaded.
*
* FUTURE options to control:
*
* special named databases
* pragma TEMP STORE = MEMORY
* TRUNCATE JOURNAL
* SYNCHRONOUS = full
*
* @param options
* (Object) Parameters to control connection and open options.
*
* @return Promise<OpenedConnection>
*/
function openConnection(options) {
let logger = createLoggerWithPrefix("ConnectionOpener");
if (!options.path) {
throw new Error("path not specified in connection options.");
}
if (isClosed()) {
throw new Error(
"Sqlite.sys.mjs has been shutdown. Cannot open connection to: " +
options.path
);
}
// Retains absolute paths and normalizes relative as relative to profile.
let path = options.path;
let file;
try {
file = lazy.FileUtils.File(path);
} catch (ex) {
// For relative paths, we will get an exception from trying to initialize
// the file. We must then join this path to the profile directory.
if (ex.result == Cr.NS_ERROR_FILE_UNRECOGNIZED_PATH) {
path = PathUtils.joinRelative(
Services.dirsvc.get("ProfD", Ci.nsIFile).path,
options.path
);
file = lazy.FileUtils.File(path);
} else {
throw ex;
}
}
let sharedMemoryCache =
"sharedMemoryCache" in options ? options.sharedMemoryCache : true;
let openedOptions = {};
if ("shrinkMemoryOnConnectionIdleMS" in options) {
if (!Number.isInteger(options.shrinkMemoryOnConnectionIdleMS)) {
throw new Error(
"shrinkMemoryOnConnectionIdleMS must be an integer. " +
"Got: " +
options.shrinkMemoryOnConnectionIdleMS
);
}
openedOptions.shrinkMemoryOnConnectionIdleMS =
options.shrinkMemoryOnConnectionIdleMS;
}
if ("defaultTransactionType" in options) {
let defaultTransactionType = options.defaultTransactionType;
if (!OpenedConnection.TRANSACTION_TYPES.includes(defaultTransactionType)) {
throw new Error(
"Unknown default transaction type: " + defaultTransactionType
);
}
openedOptions.defaultTransactionType = defaultTransactionType;
}
if ("vacuumOnIdle" in options) {
if (typeof options.vacuumOnIdle != "boolean") {
throw new Error("Invalid vacuumOnIdle: " + options.vacuumOnIdle);
}
openedOptions.vacuumOnIdle = options.vacuumOnIdle;
}
if ("incrementalVacuum" in options) {
if (typeof options.incrementalVacuum != "boolean") {
throw new Error(
"Invalid incrementalVacuum: " + options.incrementalVacuum
);
}
openedOptions.incrementalVacuum = options.incrementalVacuum;
}
if ("pageSize" in options) {
if (
![512, 1024, 2048, 4096, 8192, 16384, 32768, 65536].includes(
options.pageSize
)
) {
throw new Error("Invalid pageSize: " + options.pageSize);
}
openedOptions.pageSize = options.pageSize;
}
let identifier = getIdentifierByFileName(PathUtils.filename(path));
logger.debug("Opening database: " + path + " (" + identifier + ")");
return new Promise((resolve, reject) => {
let dbOpenOptions = Ci.mozIStorageService.OPEN_DEFAULT;
if (sharedMemoryCache) {
dbOpenOptions |= Ci.mozIStorageService.OPEN_SHARED;
}
if (options.readOnly) {
dbOpenOptions |= Ci.mozIStorageService.OPEN_READONLY;
}
if (options.ignoreLockingMode) {
dbOpenOptions |= Ci.mozIStorageService.OPEN_IGNORE_LOCKING_MODE;
dbOpenOptions |= Ci.mozIStorageService.OPEN_READONLY;
}
if (options.openNotExclusive) {
dbOpenOptions |= Ci.mozIStorageService.OPEN_NOT_EXCLUSIVE;
}
let dbConnectionOptions = Ci.mozIStorageService.CONNECTION_DEFAULT;
Services.storage.openAsyncDatabase(
file,
dbOpenOptions,
dbConnectionOptions,
async (status, connection) => {
if (!connection) {
logger.error(`Could not open connection to ${path}: ${status}`);
let error = new Components.Exception(
`Could not open connection to ${path}: ${status}`,
status
);
reject(error);
return;
}
logger.debug("Connection opened");
connection.QueryInterface(Ci.mozIStorageAsyncConnection);
if (options.testDelayedOpenPromise) {
await options.testDelayedOpenPromise;
}
if (options.extensions) {
for (let extension of options.extensions) {
try {
await new Promise((resolve2, reject2) =>
connection.loadExtension(extension, rv => {
if (Components.isSuccessCode(rv)) {
resolve2();
} else {
reject2(rv);
}
})
);
} catch (ex) {
logger.error(`Could not load extension '${extension}'`, ex);
connection.asyncClose();
reject(
new Error(`Could not load extension '${extension}'`, {
cause: ex,
})
);
return;
}
}
}
if (isClosed()) {
connection.asyncClose();
reject(
new Error(
"Sqlite.sys.mjs has been shutdown. Cannot open connection to: " +
options.path
)
);
return;
}
try {
resolve(new OpenedConnection(connection, identifier, openedOptions));
} catch (ex) {
logger.error("Could not open database", ex);
connection.asyncClose();
reject(ex);
}
}
);
});
}
/**
* Creates a clone of an existing and open Storage connection. The clone has
* the same underlying characteristics of the original connection and is
* returned in form of an OpenedConnection handle.
*
* The following parameters can control the cloned connection:
*
* connection -- (mozIStorageAsyncConnection) The original Storage connection
* to clone. It's not possible to clone connections to memory databases.
*
* readOnly -- (boolean) - If true the clone will be read-only. If the
* original connection is already read-only, the clone will be, regardless
* of this option. If the original connection is using the shared cache,
* this parameter will be ignored and the clone will be as privileged as
* the original connection.
* shrinkMemoryOnConnectionIdleMS -- (integer) If defined, the connection
* will attempt to minimize its memory usage after this many
* milliseconds of connection idle. The connection is idle when no
* statements are executing. There is no default value which means no
* automatic memory minimization will occur. Please note that this is
* *not* a timer on the idle service and this could fire while the
* application is active.
*
*
* @param options
* (Object) Parameters to control connection and clone options.
*
* @return Promise<OpenedConnection>
*/
function cloneStorageConnection(options) {
let logger = createLoggerWithPrefix("ConnectionCloner");
let source = options && options.connection;
if (!source) {
throw new TypeError("connection not specified in clone options.");
}
if (!(source instanceof Ci.mozIStorageAsyncConnection)) {
throw new TypeError("Connection must be a valid Storage connection.");
}
if (isClosed()) {
throw new Error(
"Sqlite.sys.mjs has been shutdown. Cannot clone connection to: " +
source.databaseFile.path
);
}
let openedOptions = {};
if ("shrinkMemoryOnConnectionIdleMS" in options) {
if (!Number.isInteger(options.shrinkMemoryOnConnectionIdleMS)) {
throw new TypeError(
"shrinkMemoryOnConnectionIdleMS must be an integer. " +
"Got: " +
options.shrinkMemoryOnConnectionIdleMS
);
}
openedOptions.shrinkMemoryOnConnectionIdleMS =
options.shrinkMemoryOnConnectionIdleMS;
}
let path = source.databaseFile.path;
let identifier = getIdentifierByFileName(PathUtils.filename(path));
logger.debug("Cloning database: " + path + " (" + identifier + ")");
return new Promise((resolve, reject) => {
source.asyncClone(!!options.readOnly, (status, connection) => {
if (!connection) {
logger.error("Could not clone connection: " + status);
reject(new Error("Could not clone connection: " + status));
return;
}
logger.debug("Connection cloned");
if (isClosed()) {
connection.QueryInterface(Ci.mozIStorageAsyncConnection).asyncClose();
reject(
new Error(
"Sqlite.sys.mjs has been shutdown. Cannot open connection to: " +
options.path
)
);
return;
}
try {
let conn = connection.QueryInterface(Ci.mozIStorageAsyncConnection);
resolve(new OpenedConnection(conn, identifier, openedOptions));
} catch (ex) {
logger.error("Could not clone database", ex);
connection.asyncClose();
reject(ex);
}
});
});
}
/**
* Wraps an existing and open Storage connection with Sqlite.sys.mjs API. The
* wrapped connection clone has the same underlying characteristics of the
* original connection and is returned in form of an OpenedConnection handle.
*
* Clients are responsible for closing both the Sqlite.sys.mjs wrapper and the
* underlying mozStorage connection.
*
* The following parameters can control the wrapped connection:
*
* connection -- (mozIStorageAsyncConnection) The original Storage connection
* to wrap.
*
* @param options
* (Object) Parameters to control connection and wrap options.
*
* @return Promise<OpenedConnection>
*/
function wrapStorageConnection(options) {
let logger = createLoggerWithPrefix("ConnectionWrapper");
let connection = options && options.connection;
if (!connection || !(connection instanceof Ci.mozIStorageAsyncConnection)) {
throw new TypeError("connection not specified or invalid.");
}
if (isClosed()) {
throw new Error(
"Sqlite.sys.mjs has been shutdown. Cannot wrap connection to: " +
connection.databaseFile.path
);
}
let identifier = getIdentifierByFileName(connection.databaseFile.leafName);
logger.debug("Wrapping database: " + identifier);
return new Promise(resolve => {
try {
let conn = connection.QueryInterface(Ci.mozIStorageAsyncConnection);
let wrapper = new OpenedConnection(conn, identifier);
// We must not handle shutdown of a wrapped connection, since that is
// already handled by the opener.
wrappedConnections.add(identifier);
resolve(wrapper);
} catch (ex) {
logger.error("Could not wrap database", ex);
throw ex;
}
});
}
/**
* Handle on an opened SQLite database.
*
* This is essentially a glorified wrapper around mozIStorageConnection.
* However, it offers some compelling advantages.
*
* The main functions on this type are `execute` and `executeCached`. These are
* ultimately how all SQL statements are executed. It's worth explaining their
* differences.
*
* `execute` is used to execute one-shot SQL statements. These are SQL
* statements that are executed one time and then thrown away. They are useful
* for dynamically generated SQL statements and clients who don't care about
* performance (either their own or wasting resources in the overall
* application). Because of the performance considerations, it is recommended
* to avoid `execute` unless the statement you are executing will only be
* executed once or seldomly.
*
* `executeCached` is used to execute a statement that will presumably be
* executed multiple times. The statement is parsed once and stuffed away
* inside the connection instance. Subsequent calls to `executeCached` will not
* incur the overhead of creating a new statement object. This should be used
* in preference to `execute` when a specific SQL statement will be executed
* multiple times.
*
* Instances of this type are not meant to be created outside of this file.
* Instead, first open an instance of `UnopenedSqliteConnection` and obtain
* an instance of this type by calling `open`.
*
* FUTURE IMPROVEMENTS
*
* Ability to enqueue operations. Currently there can be race conditions,
* especially as far as transactions are concerned. It would be nice to have
* an enqueueOperation(func) API that serially executes passed functions.
*
* Support for SAVEPOINT (named/nested transactions) might be useful.
*
* @param connection
* (mozIStorageConnection) Underlying SQLite connection.
* @param identifier
* (string) The unique identifier of this database. It may be used for
* logging or as a key in Maps.
* @param options [optional]
* (object) Options to control behavior of connection. See
* `openConnection`.
*/
function OpenedConnection(connection, identifier, options = {}) {
// Store all connection data in a field distinct from the
// witness. This enables us to store an additional reference to this
// field without preventing garbage collection of
// OpenedConnection. On garbage collection, we will still be able to
// close the database using this extra reference.
this._connectionData = new ConnectionData(connection, identifier, options);
// Store the extra reference in a map with connection identifier as
// key.
ConnectionData.byId.set(
this._connectionData._identifier,
this._connectionData
);
// Make a finalization witness. If this object is garbage collected
// before its `forget` method has been called, an event with topic
// "sqlite-finalization-witness" is broadcasted along with the
// connection identifier string of the database.
this._witness = lazy.FinalizationWitnessService.make(
"sqlite-finalization-witness",
this._connectionData._identifier
);
}
OpenedConnection.TRANSACTION_TYPES = ["DEFERRED", "IMMEDIATE", "EXCLUSIVE"];
// Converts a `mozIStorageAsyncConnection::TRANSACTION_*` constant into the
// corresponding `OpenedConnection.TRANSACTION_TYPES` constant.
function convertStorageTransactionType(type) {
if (!(type in OpenedConnection.TRANSACTION_TYPES)) {
throw new Error("Unknown storage transaction type: " + type);
}
return OpenedConnection.TRANSACTION_TYPES[type];
}
OpenedConnection.prototype = Object.freeze({
TRANSACTION_DEFAULT: "DEFAULT",
TRANSACTION_DEFERRED: "DEFERRED",
TRANSACTION_IMMEDIATE: "IMMEDIATE",
TRANSACTION_EXCLUSIVE: "EXCLUSIVE",
/**
* Returns a handle to the underlying `mozIStorageAsyncConnection`. This is
* ⚠️ **extremely unsafe** ⚠️ because `Sqlite.sys.mjs` continues to manage the
* connection's lifecycle, including transactions and shutdown blockers.
* Misusing the raw connection can easily lead to data loss, memory leaks,
* and errors.
*
* Consumers of the raw connection **must not** close or re-wrap it,
* and should not run statements concurrently with `Sqlite.sys.mjs`.
*
* It's _much_ safer to open a `mozIStorage{Async}Connection` yourself,
* and access it from JavaScript via `Sqlite.wrapStorageConnection`.
* `unsafeRawConnection` is an escape hatch for cases where you can't
* do that.
*
* Please do _not_ add new uses of `unsafeRawConnection` without review
* from a storage peer.
*/
get unsafeRawConnection() {
return this._connectionData._dbConn;
},
/**
* Returns the maximum number of bound parameters for statements executed
* on this connection.
*
* @returns {number} The bound parameters limit.
*/
get variableLimit() {
return this.unsafeRawConnection.variableLimit;
},
/**
* Set the the maximum number of bound parameters for statements executed
* on this connection. If the passed-in value is higher than the maximum
* default value, it will be silently truncated.
*
* @param {number} newLimit The bound parameters limit.
*/
set variableLimit(newLimit) {
this.unsafeRawConnection.variableLimit = newLimit;
},
/**
* The integer schema version of the database.
*
* This is 0 if not schema version has been set.
*
* @return Promise<int>
*/
getSchemaVersion(schemaName = "main") {
return this.execute(`PRAGMA ${schemaName}.user_version`).then(result =>
result[0].getInt32(0)
);
},
setSchemaVersion(value, schemaName = "main") {
if (!Number.isInteger(value)) {
// Guarding against accidental SQLi
throw new TypeError("Schema version must be an integer. Got " + value);
}
this._connectionData.ensureOpen();
return this.execute(`PRAGMA ${schemaName}.user_version = ${value}`);
},
/**
* Close the database connection.
*
* This must be performed when you are finished with the database.
*
* Closing the database connection has the side effect of forcefully
* cancelling all active statements. Therefore, callers should ensure that
* all active statements have completed before closing the connection, if
* possible.
*
* The returned promise will be resolved once the connection is closed.
* Successive calls to close() return the same promise.
*
* IMPROVEMENT: Resolve the promise to a closed connection which can be
* reopened.
*
* @return Promise<>
*/
close() {
// Unless cleanup has already been done by a previous call to
// `close`, delete the database entry from map and tell the
// finalization witness to forget.
if (ConnectionData.byId.has(this._connectionData._identifier)) {
ConnectionData.byId.delete(this._connectionData._identifier);
this._witness.forget();
}
return this._connectionData.close();
},
/**
* Clones this connection to a new Sqlite one.
*
* The following parameters can control the cloned connection:
*
* @param readOnly
* (boolean) - If true the clone will be read-only. If the original
* connection is already read-only, the clone will be, regardless of
* this option. If the original connection is using the shared cache,
* this parameter will be ignored and the clone will be as privileged as
* the original connection.
*
* @return Promise<OpenedConnection>
*/
clone(readOnly = false) {
return this._connectionData.clone(readOnly);
},
executeBeforeShutdown(name, task) {
return this._connectionData.executeBeforeShutdown(this, name, task);
},
/**
* Execute a SQL statement and cache the underlying statement object.
*
* This function executes a SQL statement and also caches the underlying
* derived statement object so subsequent executions are faster and use
* less resources.
*
* This function optionally binds parameters to the statement as well as
* optionally invokes a callback for every row retrieved.
*
* By default, no parameters are bound and no callback will be invoked for
* every row.
*
* Bound parameters can be defined as an Array of positional arguments or
* an object mapping named parameters to their values. If there are no bound
* parameters, the caller can pass nothing or null for this argument.
*
* Callers are encouraged to pass objects rather than Arrays for bound
* parameters because they prevent foot guns. With positional arguments, it
* is simple to modify the parameter count or positions without fixing all
* users of the statement. Objects/named parameters are a little safer
* because changes in order alone won't result in bad things happening.
*
* When `onRow` is not specified, all returned rows are buffered before the
* returned promise is resolved. For INSERT or UPDATE statements, this has
* no effect because no rows are returned from these. However, it has
* implications for SELECT statements.
*
* If your SELECT statement could return many rows or rows with large amounts
* of data, for performance reasons it is recommended to pass an `onRow`
* handler. Otherwise, the buffering may consume unacceptable amounts of
* resources.
*
* If the second parameter of an `onRow` handler is called during execution
* of the `onRow` handler, the execution of the statement is immediately
* cancelled. Subsequent rows will not be processed and no more `onRow`
* invocations will be made. The promise is resolved immediately.
*
* If an exception is thrown by the `onRow` handler, the exception is logged
* and processing of subsequent rows occurs as if nothing happened. The
* promise is still resolved (not rejected).
*
* The return value is a promise that will be resolved when the statement
* has completed fully.
*
* The promise will be rejected with an `Error` instance if the statement
* did not finish execution fully. The `Error` may have an `errors` property.
* If defined, it will be an Array of objects describing individual errors.
* Each object has the properties `result` and `message`. `result` is a
* numeric error code and `message` is a string description of the problem.
*
* @param name
* (string) The name of the registered statement to execute.
* @param params optional
* (Array or object) Parameters to bind.
* @param onRow optional
* (function) Callback to receive each row from result.
*/
executeCached(sql, params = null, onRow = null) {
if (isInvalidBoundLikeQuery(sql)) {
throw new Error("Please enter a LIKE clause with bindings");
}
return this._connectionData.executeCached(sql, params, onRow);
},
/**
* Execute a one-shot SQL statement.
*
* If you find yourself feeding the same SQL string in this function, you
* should *not* use this function and instead use `executeCached`.
*
* See `executeCached` for the meaning of the arguments and extended usage info.
*
* @param sql
* (string) SQL to execute.
* @param params optional
* (Array or Object) Parameters to bind to the statement.
* @param onRow optional
* (function) Callback to receive result of a single row.
*/
execute(sql, params = null, onRow = null) {
if (isInvalidBoundLikeQuery(sql)) {
throw new Error("Please enter a LIKE clause with bindings");
}
return this._connectionData.execute(sql, params, onRow);
},
/**
* The default behavior for transactions run on this connection.
*/
get defaultTransactionType() {
return this._connectionData.defaultTransactionType;
},
/**
* Whether a transaction is currently in progress.
*
* Note that this is true if a transaction is active on the connection,
* regardless of whether it was started by `Sqlite.sys.mjs` or another consumer.
* See the explanation above `mozIStorageConnection.transactionInProgress` for
* why this distinction matters.
*/
get transactionInProgress() {
return this._connectionData.transactionInProgress;
},
/**
* Perform a transaction.
*
* *****************************************************************************
* YOU SHOULD _NEVER_ NEST executeTransaction CALLS FOR ANY REASON, NOR
* DIRECTLY, NOR THROUGH OTHER PROMISES.
* FOR EXAMPLE, NEVER DO SOMETHING LIKE:
* await executeTransaction(async function () {
* ...some_code...
* await executeTransaction(async function () { // WRONG!
* ...some_code...
* })
* await someCodeThatExecuteTransaction(); // WRONG!
* await neverResolvedPromise; // WRONG!
* });
* NESTING CALLS WILL BLOCK ANY FUTURE TRANSACTION UNTIL A TIMEOUT KICKS IN.
* *****************************************************************************
*
* A transaction is specified by a user-supplied function that is an
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