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fix: memory leak introduced in [email protected] #13

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fix: memory leak introduced in [email protected] #13

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0163764
fix: memory leak introduced in [email protected]
analog-nico Oct 27, 2025
5f4fead
fix: memory leak introduced in [email protected]
analog-nico Oct 28, 2025
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270 changes: 143 additions & 127 deletions index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -1248,6 +1248,23 @@ class Tangerine extends dns.promises.Resolver {
}
}

// #createAbortController and #releaseAbortController manage all AbortController instances created by this resolver
// - to support cancel() and
// - to avoid keeping references in this.abortControllers after a query is finished (which would create a memory leak)
#createAbortController() {
const abortController = new AbortController();
this.abortControllers.add(abortController);
return abortController;
}

#releaseAbortController(abortController) {
try {
this.abortControllers.delete(abortController);
} catch (err) {
this.options.logger.debug(err);
}
}

// Cancel all outstanding DNS queries made by this resolver
// NOTE: callbacks not currently called with ECANCELLED (prob need to alter got options)
// (instead they are called with "ABORT_ERR"; see ABORT_ERROR_CODES)
Expand All @@ -1265,120 +1282,116 @@ class Tangerine extends dns.promises.Resolver {

#resolveByType(name, options = {}, parentAbortController) {
return async (type) => {
const abortController = new AbortController();
this.abortControllers.add(abortController);
abortController.signal.addEventListener(
'abort',
() => {
this.abortControllers.delete(abortController);
},
{ once: true }
);
parentAbortController.signal.addEventListener(
'abort',
() => {
try {
abortController.abort('Parent abort controller aborted');
} catch (err) {
this.options.logger.debug(err);
}
},
{ once: true }
);
// wrap with try/catch because ENODATA shouldn't cause errors
const abortController = this.#createAbortController();
try {
switch (type) {
case 'A': {
const result = await this.resolve4(
name,
{ ...options, ttl: true },
abortController
);
return result.map((r) => ({ type, ...r }));
}
parentAbortController.signal.addEventListener(
'abort',
() => {
try {
abortController.abort('Parent abort controller aborted');
} catch (err) {
this.options.logger.debug(err);
}
},
{ once: true }
);
// wrap with try/catch because ENODATA shouldn't cause errors
try {
switch (type) {
case 'A': {
const result = await this.resolve4(
name,
{ ...options, ttl: true },
abortController
);
return result.map((r) => ({ type, ...r }));
}

case 'AAAA': {
const result = await this.resolve6(
name,
{ ...options, ttl: true },
abortController
);
return result.map((r) => ({ type, ...r }));
}
case 'AAAA': {
const result = await this.resolve6(
name,
{ ...options, ttl: true },
abortController
);
return result.map((r) => ({ type, ...r }));
}

case 'CNAME': {
const result = await this.resolveCname(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}
case 'CNAME': {
const result = await this.resolveCname(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}

case 'MX': {
const result = await this.resolveMx(name, options, abortController);
return result.map((r) => ({ type, ...r }));
}
case 'MX': {
const result = await this.resolveMx(name, options, abortController);
return result.map((r) => ({ type, ...r }));
}

case 'NAPTR': {
const result = await this.resolveNaptr(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}
case 'NAPTR': {
const result = await this.resolveNaptr(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}

case 'NS': {
const result = await this.resolveNs(name, options, abortController);
return result.map((value) => ({ type, value }));
}
case 'NS': {
const result = await this.resolveNs(name, options, abortController);
return result.map((value) => ({ type, value }));
}

case 'PTR': {
const result = await this.resolvePtr(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}
case 'PTR': {
const result = await this.resolvePtr(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}

case 'SOA': {
const result = await this.resolveSoa(
name,
options,
abortController
);
return { type, ...result };
}
case 'SOA': {
const result = await this.resolveSoa(
name,
options,
abortController
);
return { type, ...result };
}

case 'SRV': {
const result = await this.resolveSrv(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}
case 'SRV': {
const result = await this.resolveSrv(
name,
options,
abortController
);
return result.map((value) => ({ type, value }));
}

case 'TXT': {
const result = await this.resolveTxt(
name,
options,
abortController
);
return result.map((entries) => ({ type, entries }));
}
case 'TXT': {
const result = await this.resolveTxt(
name,
options,
abortController
);
return result.map((entries) => ({ type, entries }));
}

default: {
break;
default: {
break;
}
}
}
} catch (err) {
debug(err);
} catch (err) {
debug(err);

if (err.code === dns.NODATA) return;
throw err;
if (err.code === dns.NODATA) return;
throw err;
}
} finally {
this.#releaseAbortController(abortController);
}
};
}
Expand All @@ -1394,23 +1407,22 @@ class Tangerine extends dns.promises.Resolver {
// <https://gist.github.com/andrewcourtice/ef1b8f14935b409cfe94901558ba5594#file-task-ts-L37>
// <https://github.com/nodejs/undici/blob/0badd390ad5aa531a66aacee54da664468aa1577/lib/api/api-fetch/request.js#L280-L295>
// <https://github.com/nodejs/node/issues/40849>
let mustReleaseAbortController = false;
if (!abortController) {
abortController = new AbortController();
this.abortControllers.add(abortController);
abortController.signal.addEventListener(
'abort',
() => {
this.abortControllers.delete(abortController);
},
{ once: true }
);
abortController = this.#createAbortController();
mustReleaseAbortController = true;

// <https://github.com/nodejs/undici/pull/1910/commits/7615308a92d3c8c90081fb99c55ab8bd59212396>
setMaxListeners(
getEventListeners(abortController.signal, 'abort').length +
this.constructor.ANY_TYPES.length,
abortController.signal
);
try {
// <https://github.com/nodejs/undici/pull/1910/commits/7615308a92d3c8c90081fb99c55ab8bd59212396>
setMaxListeners(
getEventListeners(abortController.signal, 'abort').length +
this.constructor.ANY_TYPES.length,
abortController.signal
);
} catch (err) {
this.#releaseAbortController(abortController);
throw err;
}
}

try {
Expand All @@ -1428,6 +1440,10 @@ class Tangerine extends dns.promises.Resolver {
err.syscall = 'queryAny';
err.message = `queryAny ${err.code} ${name}`;
throw err;
} finally {
if (mustReleaseAbortController) {
this.#releaseAbortController(abortController);
}
}
}

Expand Down Expand Up @@ -1674,20 +1690,20 @@ class Tangerine extends dns.promises.Resolver {
if (this.options.cache && result) {
debug(`cached result found for "${key}"`);
} else {
let mustReleaseAbortController = false;
if (!abortController) {
abortController = new AbortController();
this.abortControllers.add(abortController);
abortController.signal.addEventListener(
'abort',
() => {
this.abortControllers.delete(abortController);
},
{ once: true }
);
abortController = this.#createAbortController();
mustReleaseAbortController = true;
}

// setImmediate(() => this.cancel());
result = await this.#query(name, rrtype, ecsSubnet, abortController);
try {
// setImmediate(() => this.cancel());
result = await this.#query(name, rrtype, ecsSubnet, abortController);
} finally {
if (mustReleaseAbortController) {
this.#releaseAbortController(abortController);
}
}
}

// <https://github.com/m13253/dns-over-https/blob/2e36b4ebcdb8a1a102ea86370d7f8b1f1e72380a/json-dns/response.go#L50-L74>
Expand Down