contextor - npm Package Compare versions

Comparing version 0.5.0 to 0.6.0

index.js

 'use strict';
 
 const asyncHooks = require('async_hooks');
-const v8 = require('v8');
-const vm = require('vm');
 
-let gc = global.gc;
-
-if (!gc) {
-  v8.setFlagsFromString('--expose_gc');
-  gc = vm.runInNewContext('gc');
-}
-
 // Module global variables.
 const resourceTree = {};
 const contexts = {};
+const contextAges = {};
 const childResources = {};
@@ -21,3 +13,49 @@ const parentResources = {};
 
+let createdContextNumberSinceLastCleanCheck = 0;
+
+const CLEAN_CHECK_CONTEXT_SIZE = process.env.CONTEXTOR_CLEAN_CHECK_CONTEXT_SIZE || 100;
+const CONTEXT_TTL = process.env.CONTEXTOR_CONTEXT_TTL || 6e4;
+
 /**
+ * Retrieve context id for an async resource.
+ * @param {number} asyncId - The resource id.
+ * @returns {number|undefined} The context id or undefined if not in a context.
+ */
+function retrieveContextId(asyncId) {
+  let contextId = asyncId;
+
+  while (contextId !== undefined && !(contextId in contexts)) {
+    contextId = resourceTree[contextId];
+  }
+
+  return contextId;
+}
+
+/**
+ * Retrieve current context id.
+ * @returns {number|undefined} The current context id or undefined if not in a context.
+ */
+function retrieveCurrentContextId() {
+  return retrieveContextId(asyncHooks.executionAsyncId());
+}
+
+/**
+ * Retrieve current context.
+ * @returns {Object} The current context.
+ * @throws {ReferenceError} On missing current context.
+ */
+function retrieveCurrentContext() {
+  const asyncId = retrieveCurrentContextId();
+  const exists = asyncId in contexts;
+
+  if (!exists) {
+    throw new ReferenceError(
+      'No current context found; use \'create\' method to create one'
+    );
+  }
+
+  return contexts[asyncId];
+}
+
+/**
  * Async hook init callback.
@@ -29,6 +67,2 @@ * - build resource tree allowing to resolve current context
 function init(asyncId, type, triggerAsyncId) {
-  if (!triggerAsyncId) {
-    return;
-  }
-
   resourceTree[asyncId] = triggerAsyncId;
@@ -57,3 +91,3 @@
 
-  // Clean memory.
+  // Clean memory references.
   const resources = [asyncId].concat(parentResources[asyncId]);
@@ -78,6 +112,8 @@
     const destroyed = parentAsyncId in destroyedResources;
+    const hasContext = !!retrieveContextId(parentAsyncId);
 
-    if (!hasChildren && destroyed) {
+    if ((!hasChildren && destroyed) || !hasContext) {
       delete resourceTree[parentAsyncId];
       delete contexts[parentAsyncId];
+      delete contextAges[parentAsyncId];
       delete childResources[parentAsyncId];
@@ -98,38 +134,26 @@ delete parentResources[parentAsyncId];
 /**
- * Retrieve current context id.
- * @returns {number|undefined} The current context id.
+ * Clean deprecated and useless resources.
  */
-function retrieveCurrentContextId() {
-  let asyncId = asyncHooks.executionAsyncId();
+function cleanResources() {
+  const now = Date.now();
 
-  while (asyncId !== undefined && !(asyncId in contexts)) {
-    asyncId = resourceTree[asyncId];
+  // Clean expired contexts (in case a destroy has not been fired).
+  if (CONTEXT_TTL) {
+    Object.getOwnPropertyNames(contexts).forEach((asyncId) => {
+      if (now - contextAges[asyncId] >= CONTEXT_TTL) {
+        delete contexts[asyncId];
+        delete contextAges[asyncId];
+      }
+    });
   }
 
-  return asyncId;
+  // Clean resources not attached to a context.
+  Object.getOwnPropertyNames(resourceTree).forEach((asyncId) => {
+    if (!retrieveContextId(asyncId)) {
+      destroy(asyncId);
+    }
+  });
 }
 
 /**
- * Retrieve current context.
- * @returns {Object} The current context.
- * @throws {ReferenceError} On missing current context.
- */
-function retrieveCurrentContext() {
-  const asyncId = retrieveCurrentContextId();
-  const exists = asyncId in contexts;
-
-  if (!exists) {
-    throw new ReferenceError(
-      'No current context found; use \'create\' method to create one'
-    );
-  }
-
-  return contexts[asyncId];
-}
-
-let createdContextNumberSinceLastCleanCheck = 0;
-const CLEAN_CHECK_CONTEXT_SIZE = process.env.CONTEXTOR_CLEAN_CHECK_CONTEXT_SIZE || 100;
-const DESTROY_STACK_SIZE = process.env.CONTEXTOR_DESTROY_STACK_SIZE || 1000;
-
-/**
  * Create a new context.
@@ -141,11 +165,7 @@ * @returns {self}
   contexts[asyncId] = {};
+  contextAges[asyncId] = Date.now();
 
-  // Call manual garbage collector execution on garbage stacking.
-  if (createdContextNumberSinceLastCleanCheck >= CLEAN_CHECK_CONTEXT_SIZE) {
-    if (Object.getOwnPropertyNames(destroyedResources).length >= DESTROY_STACK_SIZE) {
-      gc();
-    }
+  if (++createdContextNumberSinceLastCleanCheck >= CLEAN_CHECK_CONTEXT_SIZE) {
+    cleanResources();
     createdContextNumberSinceLastCleanCheck = 0;
-  } else {
-    createdContextNumberSinceLastCleanCheck++;
   }
@@ -152,0 +172,0 @@

package.json

 {
   "name": "contextor",
   "description": "Package allowing to pass a context along an asynchronous process",
-  "version": "0.5.0",
+  "version": "0.6.0",
   "author": "Thomas Prelot <[e-mail]> (https://github.com/Gnucki)",
@@ -28,7 +28,7 @@ "contributors": [],
     "lint-fix": "gnodi-lint --fix",
-    "test": "NODE_ENV='test' mocha --recursive index.js test.js",
+    "test": "NODE_ENV=test CONTEXTOR_CLEAN_CHECK_CONTEXT_SIZE=2 CONTEXTOR_CONTEXT_TTL=200 mocha --recursive index.js test.js",
     "test-coverage": "nyc npm test && nyc report --reporter text-summary",
     "test-coveralls": "nyc npm test && nyc report --reporter text-lcov | coveralls",
-    "test-debug": "NODE_ENV='test' mocha --recursive --full-trace --check-leaks index.js test.js",
-    "test-watch": "NODE_ENV='test' mocha -w -b --recursive index.js test.js",
+    "test-debug": "NODE_ENV=test CONTEXTOR_CLEAN_CHECK_CONTEXT_SIZE=2 CONTEXTOR_CONTEXT_TTL=200 mocha --recursive --full-trace --check-leaks index.js test.js",
+    "test-watch": "NODE_ENV=test CONTEXTOR_CLEAN_CHECK_CONTEXT_SIZE=2 CONTEXTOR_CONTEXT_TTL=200 mocha -w -b --recursive index.js test.js",
     "preversion": "npm run check",
@@ -35,0 +35,0 @@ "postversion": "git push && git push --tags"

README.md

@@ -65,2 +65,3 @@ # contextor
   - [Get a value in the current context](#get-a-value-in-the-current-context)
+  - [Customize cleaning](#customize-cleaning)
 - [Debugging](#debugging)
@@ -111,2 +112,7 @@ - [Testing](#testing)
 
+### Customize cleaning
+Some environment variables are available in order to customize context cleaning:
+- `CONTEXTOR_CLEAN_CHECK_CONTEXT_SIZE`: number of created contexts before a cleaning is executed (default: 100)
+- `CONTEXTOR_CONTEXT_TTL`: TTL of contexts in ms; set to 0 to make it infinite (default: 6e4)
+
 ### Debugging
@@ -113,0 +119,0 @@ Contextor create context for async hooks. A bad usage can lead to memory leaks.<br>

test.js

@@ -138,2 +138,34 @@ 'use strict';
   });
+
+  it('should clean expired contexts', (done) => {
+    let memoryUsage = contextor.getMemoryUsage();
+
+    expect(memoryUsage.sizes.contexts).to.be.greaterThan(1);
+
+    setTimeout(() => {
+      contextor.create();
+      contextor.create();
+      memoryUsage = contextor.getMemoryUsage();
+
+      expect(memoryUsage.sizes.contexts).equal(1);
+
+      setTimeout(() => {
+        contextor.create();
+        contextor.create();
+        memoryUsage = contextor.getMemoryUsage();
+
+        expect(memoryUsage.sizes.contexts).equal(1);
+
+        done();
+      }, 400);
+    }, 400);
+
+    setTimeout(() => {
+      contextor.create();
+      contextor.create();
+      memoryUsage = contextor.getMemoryUsage();
+
+      expect(memoryUsage.sizes.contexts).equal(2);
+    }, 500);
+  });
 });

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Package accesses environment variables, which may be a sign of credential stuffing or data theft.

Found 1 instance in 1 package

Fixed alerts

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Debug access

Supply chain risk

Uses debug, reflection and dynamic code execution features.

Found 2 instances in 1 package

Environment variable access

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Package accesses environment variables, which may be a sign of credential stuffing or data theft.

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Improved metrics

Total package byte prevSize

21785

increased by9.96%

Lines of code

394

increased by11.61%

Number of lines in readme file

171

increased by3.64%

Number of low supply chain risk alerts

3

decreased by-40%

No dependency changes