feat: info functions

1 files changed, 96 insertions, 0 deletions

diff --git a/src/helpers/memorySize.js b/src/helpers/memorySize.js
new file mode 100644
index 0000000..044681a
--- /dev/null
+++ b/src/helpers/memorySize.js
@@ -0,0 +1,96 @@
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const Buffer = require('buffer/').Buffer;
+
+const ECMA_SIZES = {
+  STRING: 2,
+  BOOLEAN: 4,
+  NUMBER: 8
+};
+
+function allProperties(obj) {
+  const stringProperties = [];
+  for (var prop in obj) {
+    stringProperties.push(prop);
+  }
+  if (Object.getOwnPropertySymbols) {
+    var symbolProperties = Object.getOwnPropertySymbols(obj);
+    Array.prototype.push.apply(stringProperties, symbolProperties);
+  }
+  return stringProperties;
+}
+
+function sizeOfObject(seen, object) {
+  if (object == null) {
+    return 0;
+  }
+
+  var bytes = 0;
+  var properties = allProperties(object);
+  for (var i = 0; i < properties.length; i++) {
+    var key = properties[i];
+    // Do not recalculate circular references
+    if (typeof object[key] === 'object' && object[key] !== null) {
+      if (seen.has(object[key])) {
+        continue;
+      }
+      seen.add(object[key]);
+    }
+
+    bytes += getCalculator(seen)(key);
+    try {
+      bytes += getCalculator(seen)(object[key]);
+    } catch (ex) {
+      if (ex instanceof RangeError) {
+        // circular reference detected, final result might be incorrect
+        // let's be nice and not throw an exception
+        bytes = 0;
+      }
+    }
+  }
+
+  return bytes;
+}
+
+function getCalculator(seen) {
+  return function calculator(object) {
+    if (Buffer.isBuffer(object)) {
+      return object.length;
+    }
+
+    var objectType = typeof object;
+    switch (objectType) {
+      case 'string':
+        return object.length * ECMA_SIZES.STRING;
+      case 'boolean':
+        return ECMA_SIZES.BOOLEAN;
+      case 'number':
+        return ECMA_SIZES.NUMBER;
+      case 'symbol':
+        // eslint-disable-next-line no-case-declarations
+        const isGlobalSymbol = Symbol.keyFor && Symbol.keyFor(object);
+        return isGlobalSymbol
+          ? Symbol.keyFor(object).length * ECMA_SIZES.STRING
+          : (object.toString().length - 8) * ECMA_SIZES.STRING;
+      case 'object':
+        if (Array.isArray(object)) {
+          return object.map(getCalculator(seen)).reduce(function (acc, curr) {
+            return acc + curr;
+          }, 0);
+        } else {
+          return sizeOfObject(seen, object);
+        }
+      default:
+        return 0;
+    }
+  };
+}
+
+/**
+ * Main module's entry point
+ * Calculates Bytes for the provided parameter
+ * @param object - handles object/string/boolean/buffer
+ * @returns {*}
+ */
+export function sizeof(object) {
+  return getCalculator(new WeakSet())(object);
+}