pulumi/sdk/nodejs/runtime/closure/serializeClosure.ts

652 lines
26 KiB
TypeScript

// Copyright 2016-2018, Pulumi Corporation.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import { log } from "../..";
import { Resource } from "../../resource";
import * as closure from "./createClosure";
import * as utils from "./utils";
/**
* {@link SerializeFunctionArgs} are arguments used to serialize a JavaScript
* function.
*/
export interface SerializeFunctionArgs {
/**
* The name to export from the module defined by the generated module text.
* Defaults to `handler`.
*/
exportName?: string;
/**
* A function to prevent serialization of certain objects captured during
* the serialization. Primarily used to prevent potential cycles.
*/
serialize?: (o: any) => boolean;
/**
* True if this is a function which, when invoked, will produce the actual
* entrypoint function. Useful for when serializing a function that has high
* startup cost that we'd ideally only run once. The signature of this
* function should be `() => (provider_handler_args...) => provider_result`.
*
* This will then be emitted as `exports.[exportName] =
* serialized_func_name();`
*
* In other words, the function will be invoked (once) and the resulting
* inner function will be what is exported.
*/
isFactoryFunction?: boolean;
/**
* The resource to log any errors we encounter against.
*/
logResource?: Resource;
/**
* If true, allow secrets to be serialized into the function. This should
* only be set to true if the calling code will handle this and propoerly
* wrap the resulting text in a secret before passing it into any resources
* or serializing it to any other output format. If set, the
* `containsSecrets` property on the returned {@link SerializedFunction}
* object will indicate whether secrets were serialized into the function
* text.
*/
allowSecrets?: boolean;
}
/**
* {@link SerializedFunction} is a representation of a serialized JavaScript
* function.
*/
export interface SerializedFunction {
/**
* The text of a JavaScript module which exports a single name bound to an
* appropriate value. In the case of a normal function, this value will just
* be serialized function. In the case of a factory function this value
* will be the result of invoking the factory function.
*/
text: string;
/**
* The name of the exported module member.
*/
exportName: string;
/**
* True if the serialized function text includes serialized secrets.
*/
containsSecrets: boolean;
}
/**
* Serializes a JavaScript function into a text form that can be loaded in
* another execution context, for example as part of a function callback
* associated with an AWS Lambda. The function serialization captures any
* variables captured by the function body and serializes those values into the
* generated text along with the function body. This process is recursive, so
* that functions referenced by the body of the serialized function will
* themselves be serialized as well. This process also deeply serializes
* captured object values, including prototype chains and property descriptors,
* such that the semantics of the function when deserialized should match the
* original function.
*
* There are several known limitations:
*
* - If a native function is captured either directly or indirectly, closure
* serialization will return an error.
*
* - Captured values will be serialized based on their values at the time that
* `serializeFunction` is called. Mutations to these values after that (but
* before the deserialized function is used) will not be observed by the
* deserialized function.
*
* @param func
* The JavaScript function to serialize.
* @param args
* Arguments to use to control the serialization of the JavaScript function.
*/
export async function serializeFunction(func: Function, args: SerializeFunctionArgs = {}): Promise<SerializedFunction> {
const exportName = args.exportName || "handler";
const serialize = args.serialize || ((_) => true);
const isFactoryFunction = args.isFactoryFunction === undefined ? false : args.isFactoryFunction;
const closureInfo = await closure.createClosureInfoAsync(func, serialize, args.logResource);
if (!args.allowSecrets && closureInfo.containsSecrets) {
throw new Error("Secret outputs cannot be captured by a closure.");
}
return serializeJavaScriptText(closureInfo, exportName, isFactoryFunction);
}
/**
* @deprecated
* Please use {@link serializeFunction} instead.
*/
export async function serializeFunctionAsync(func: Function, serialize?: (o: any) => boolean): Promise<string> {
log.warn("'function serializeFunctionAsync' is deprecated. Please use 'serializeFunction' instead.");
serialize = serialize || ((_) => true);
const closureInfo = await closure.createClosureInfoAsync(func, serialize, /*logResource:*/ undefined);
if (closureInfo.containsSecrets) {
throw new Error("Secret outputs cannot be captured by a closure.");
}
return serializeJavaScriptText(closureInfo, "handler", /*isFactoryFunction*/ false).text;
}
/**
* Converts a {@link FunctionInfo} object into a string representation of a
* NodeJS module body which exposes a single function `exports.handler`
* representing the serialized function.
*/
function serializeJavaScriptText(
outerClosure: closure.ClosureInfo,
exportName: string,
isFactoryFunction: boolean,
): SerializedFunction {
// Now produce a textual representation of the closure and its serialized captured environment.
// State used to build up the environment variables for all the funcs we generate.
// In general, we try to create idiomatic code to make the generated code not too
// hideous. For example, we will try to generate code like:
//
// var __e1 = [1, 2, 3] // or
// var __e2 = { a: 1, b: 2, c: 3 }
//
// However, for non-common cases (i.e. sparse arrays, objects with configured properties,
// etc. etc.) we will spit things out in a much more verbose fashion that eschews
// prettyness for correct semantics.
const envEntryToEnvVar = new Map<closure.Entry, string>();
const envVarNames = new Set<string>();
const functionInfoToEnvVar = new Map<closure.FunctionInfo, string>();
let environmentText = "";
let functionText = "";
const importedIdentifiers = new Map<string, ImportedIdentifier>();
const outerFunctionName = emitFunctionAndGetName(outerClosure.func);
if (environmentText) {
environmentText = "\n" + environmentText;
}
// Export the appropriate value. For a normal function, this will just be exporting the name of
// the module function we created by serializing it. For a factory function this will export
// the function produced by invoking the factory function once.
let text: string;
const exportText = `exports.${exportName} = ${outerFunctionName}${isFactoryFunction ? "()" : ""};`;
if (isFactoryFunction) {
// for a factory function, we need to call the function at the end. That way all the logic
// to set up the environment has run.
text = environmentText + functionText + "\n" + exportText;
} else {
text = exportText + "\n" + environmentText + functionText;
}
return { text, exportName, containsSecrets: outerClosure.containsSecrets };
function emitFunctionAndGetName(functionInfo: closure.FunctionInfo): string {
// If this is the first time seeing this function, then actually emit the function code for
// it. Otherwise, just return the name of the emitted function for anyone that wants to
// reference it from their own code.
let functionName = functionInfoToEnvVar.get(functionInfo);
if (!functionName) {
functionName = functionInfo.name
? createEnvVarName(functionInfo.name, /*addIndexAtEnd:*/ false)
: createEnvVarName("f", /*addIndexAtEnd:*/ true);
functionInfoToEnvVar.set(functionInfo, functionName);
emitFunctionWorker(functionInfo, functionName);
}
return functionName;
}
function emitFunctionWorker(functionInfo: closure.FunctionInfo, varName: string) {
const capturedValues = envFromEnvObj(functionInfo.capturedValues);
const thisCapture = capturedValues.this;
const argumentsCapture = capturedValues.arguments;
capturedValues.this = undefined as unknown as string;
capturedValues.arguments = undefined as unknown as string;
const parameters = [...Array(functionInfo.paramCount)].map((_, index) => `__${index}`).join(", ");
for (const [keyEntry, { entry: valEntry }] of functionInfo.capturedValues) {
if (valEntry.module === undefined) {
continue;
}
let imported = importedIdentifiers.get(keyEntry.json);
// If we haven't imported this identifier yet, we'll do so now. If
// the identifier isn't reserved, importIdentifier will instruct us
// to import it "as-is". We can thus remove it from the list of
// captured values and have it available inside the scope of the
// function (and all subsequent functions). If the identifier is
// reserved, importIdentifier will generate a suitable alias for it.
// We'll declare this now, but we'll not remove the identifier from
// the list of captures. This means that we can safely alias it as
// the reserved identifier inside relevant function scopes.
//
// As an example, consider the identifiers "foo" (not reserved) and
// "exports" (reserved).
//
// For "foo", we'll generate code like:
//
// const foo = require("some/module/foo");
//
// function x() {
// return (function () {
// with({ ... }) {
// // foo used directly
// }
// }).apply(...)
// }
//
// For "exports", importIdentifier will give us an identifier like
// "__pulumi_closure_import_exports" and we'll generate code like:
//
// const __pulumi_closure_import_exports = require("some/module/foo");
//
// function x() {
// return (function () {
// with({ exports: __pulumi_closure_import_exports, ... }) {
// // exports now available by virtue of the with()
// }
// }).apply(...)
// }
//
// This hack saves us having to rewrite the function's code while
// helping us avoid importing modules over and over again (which
// might have unintended side effects).
if (!imported) {
imported = importIdentifier(keyEntry.json);
importedIdentifiers.set(keyEntry.json, imported);
functionText += `const ${imported.as} = require("${valEntry.module}");\n`;
}
if (imported.reserved) {
capturedValues[imported.identifier] = imported.as;
} else {
delete capturedValues[keyEntry.json];
}
}
functionText +=
"\n" +
"function " +
varName +
"(" +
parameters +
") {\n" +
" return (function() {\n" +
" with(" +
envObjToString(capturedValues) +
") {\n\n" +
"return " +
functionInfo.code +
";\n\n" +
" }\n" +
" }).apply(" +
thisCapture +
", " +
argumentsCapture +
").apply(this, arguments);\n" +
"}\n";
// If this function is complex (i.e. non-default __proto__, or has properties, etc.)
// then emit those as well.
emitComplexObjectProperties(varName, varName, functionInfo);
if (functionInfo.proto !== undefined) {
const protoVar = envEntryToString(functionInfo.proto, `${varName}_proto`);
environmentText += `Object.setPrototypeOf(${varName}, ${protoVar});\n`;
}
}
function envFromEnvObj(env: closure.PropertyMap): Record<string, string> {
const envObj: Record<string, string> = {};
for (const [keyEntry, { entry: valEntry }] of env) {
if (typeof keyEntry.json !== "string") {
throw new Error("PropertyMap key was not a string.");
}
const key = keyEntry.json;
const val = envEntryToString(valEntry, key);
envObj[key] = val;
}
return envObj;
}
function envEntryToString(envEntry: closure.Entry, varName: string): string {
const envVar = envEntryToEnvVar.get(envEntry);
if (envVar !== undefined) {
return envVar;
}
// Complex objects may also be referenced from multiple functions. As such, we have to
// create variables for them in the environment so that all references to them unify to the
// same reference to the env variable. Effectively, we need to do this for any object that
// could be compared for reference-identity. Basic types (strings, numbers, etc.) have
// value semantics and this can be emitted directly into the code where they are used as
// there is no way to observe that you are getting a different copy.
if (isObjOrArrayOrRegExp(envEntry)) {
return complexEnvEntryToString(envEntry, varName);
} else {
// Other values (like strings, bools, etc.) can just be emitted inline.
return simpleEnvEntryToString(envEntry, varName);
}
}
function simpleEnvEntryToString(envEntry: closure.Entry, varName: string): string {
if (envEntry.hasOwnProperty("json")) {
return JSON.stringify(envEntry.json);
} else if (envEntry.function !== undefined) {
return emitFunctionAndGetName(envEntry.function);
} else if (envEntry.module !== undefined) {
return `require("${envEntry.module}")`;
} else if (envEntry.output !== undefined) {
return envEntryToString(envEntry.output, varName);
} else if (envEntry.expr) {
// Entry specifies exactly how it should be emitted. So just use whatever
// it wanted.
return envEntry.expr;
} else if (envEntry.promise) {
return `Promise.resolve(${envEntryToString(envEntry.promise, varName)})`;
} else {
throw new Error("Malformed: " + JSON.stringify(envEntry));
}
}
function complexEnvEntryToString(envEntry: closure.Entry, varName: string): string {
// Call all environment variables __e<num> to make them unique. But suffix
// them with the original name of the property to help provide context when
// looking at the source.
const envVar = createEnvVarName(varName, /*addIndexAtEnd:*/ false);
envEntryToEnvVar.set(envEntry, envVar);
if (envEntry.object) {
emitObject(envVar, envEntry.object, varName);
} else if (envEntry.array) {
emitArray(envVar, envEntry.array, varName);
} else if (envEntry.regexp) {
const { source, flags } = envEntry.regexp;
const regexVal = `new RegExp(${JSON.stringify(source)}, ${JSON.stringify(flags)})`;
const entryString = `var ${envVar} = ${regexVal};\n`;
environmentText += entryString;
}
return envVar;
}
function createEnvVarName(baseName: string, addIndexAtEnd: boolean): string {
const trimLeadingUnderscoreRegex = /^_*/g;
const legalName = makeLegalJSName(baseName).replace(trimLeadingUnderscoreRegex, "");
let index = 0;
let currentName = addIndexAtEnd ? "__" + legalName + index : "__" + legalName;
while (envVarNames.has(currentName)) {
currentName = addIndexAtEnd ? "__" + legalName + index : "__" + index + "_" + legalName;
index++;
}
envVarNames.add(currentName);
return currentName;
}
function emitObject(envVar: string, obj: closure.ObjectInfo, varName: string): void {
const complex = isComplex(obj);
if (complex) {
// we have a complex child. Because of the possibility of recursion in
// the object graph, we have to spit out this variable uninitialized first.
// Then we can walk our children, creating a single assignment per child.
// This way, if the child ends up referencing us, we'll have already emitted
// the **initialized** variable for them to reference.
if (obj.proto) {
const protoVar = envEntryToString(obj.proto, `${varName}_proto`);
environmentText += `var ${envVar} = Object.create(${protoVar});\n`;
} else {
environmentText += `var ${envVar} = {};\n`;
}
emitComplexObjectProperties(envVar, varName, obj);
} else {
// All values inside this obj are simple. We can just emit the object
// directly as an object literal with all children embedded in the literal.
const props: string[] = [];
for (const [keyEntry, { entry: valEntry }] of obj.env) {
const keyName = typeof keyEntry.json === "string" ? keyEntry.json : "sym";
const propName = envEntryToString(keyEntry, keyName);
const propVal = simpleEnvEntryToString(valEntry, keyName);
if (typeof keyEntry.json === "string" && utils.isLegalMemberName(keyEntry.json)) {
props.push(`${keyEntry.json}: ${propVal}`);
} else {
props.push(`[${propName}]: ${propVal}`);
}
}
const allProps = props.join(", ");
const entryString = `var ${envVar} = {${allProps}};\n`;
environmentText += entryString;
}
function isComplex(o: closure.ObjectInfo) {
if (obj.proto !== undefined) {
return true;
}
for (const v of o.env.values()) {
if (entryIsComplex(v)) {
return true;
}
}
return false;
}
function entryIsComplex(v: closure.PropertyInfoAndValue) {
return !isSimplePropertyInfo(v.info) || deepContainsObjOrArrayOrRegExp(v.entry);
}
}
function isSimplePropertyInfo(info: closure.PropertyInfo | undefined): boolean {
if (!info) {
return true;
}
return (
info.enumerable === true && info.writable === true && info.configurable === true && !info.get && !info.set
);
}
function emitComplexObjectProperties(envVar: string, varName: string, objEntry: closure.ObjectInfo): void {
for (const [keyEntry, { info, entry: valEntry }] of objEntry.env) {
const subName = typeof keyEntry.json === "string" ? keyEntry.json : "sym";
const keyString = envEntryToString(keyEntry, varName + "_" + subName);
const valString = envEntryToString(valEntry, varName + "_" + subName);
if (isSimplePropertyInfo(info)) {
// normal property. Just emit simply as a direct assignment.
if (typeof keyEntry.json === "string" && utils.isLegalMemberName(keyEntry.json)) {
environmentText += `${envVar}.${keyEntry.json} = ${valString};\n`;
} else {
environmentText += `${envVar}${`[${keyString}]`} = ${valString};\n`;
}
} else {
// complex property. emit as Object.defineProperty
emitDefineProperty(info!, valString, keyString);
}
}
function emitDefineProperty(desc: closure.PropertyInfo, entryValue: string, propName: string) {
const copy: any = {};
if (desc.configurable) {
copy.configurable = desc.configurable;
}
if (desc.enumerable) {
copy.enumerable = desc.enumerable;
}
if (desc.writable) {
copy.writable = desc.writable;
}
if (desc.get) {
copy.get = envEntryToString(desc.get, `${varName}_get`);
}
if (desc.set) {
copy.set = envEntryToString(desc.set, `${varName}_set`);
}
if (desc.hasValue) {
copy.value = entryValue;
}
const line = `Object.defineProperty(${envVar}, ${propName}, ${envObjToString(copy)});\n`;
environmentText += line;
}
}
function emitArray(envVar: string, arr: closure.Entry[], varName: string): void {
if (arr.some(deepContainsObjOrArrayOrRegExp) || isSparse(arr) || hasNonNumericIndices(arr)) {
// we have a complex child. Because of the possibility of recursion in the object
// graph, we have to spit out this variable initialized (but empty) first. Then we can
// walk our children, knowing we'll be able to find this variable if they reference it.
environmentText += `var ${envVar} = [];\n`;
// Walk the names of the array properties directly. This ensures we work efficiently
// with sparse arrays. i.e. if the array has length 1k, but only has one value in it
// set, we can just set htat value, instead of setting 999 undefineds.
for (const key of Object.getOwnPropertyNames(arr)) {
if (key !== "length") {
const entryString = envEntryToString(arr[<any>key], `${varName}_${key}`);
environmentText += `${envVar}${isNumeric(key) ? `[${key}]` : `.${key}`} = ${entryString};\n`;
}
}
} else {
// All values inside this array are simple. We can just emit the array elements in
// place. i.e. we can emit as ``var arr = [1, 2, 3]`` as that's far more preferred than
// having four individual statements to do the same.
const strings: string[] = [];
for (let i = 0, n = arr.length; i < n; i++) {
strings.push(simpleEnvEntryToString(arr[i], `${varName}_${i}`));
}
const entryString = `var ${envVar} = [${strings.join(", ")}];\n`;
environmentText += entryString;
}
}
}
(<any>serializeJavaScriptText).doNotCapture = true;
const makeLegalRegex = /[^0-9a-zA-Z_]/g;
function makeLegalJSName(n: string) {
return n.replace(makeLegalRegex, (x) => "");
}
function isSparse<T>(arr: Array<T>) {
// getOwnPropertyNames for an array returns all the indices as well as 'length'.
// so we subtract one to get all the real indices. If that's not the same as
// the array length, then we must have missing properties and are thus sparse.
return arr.length !== Object.getOwnPropertyNames(arr).length - 1;
}
function hasNonNumericIndices<T>(arr: Array<T>) {
return Object.keys(arr).some((k) => k !== "length" && !isNumeric(k));
}
function isNumeric(n: string) {
return !isNaN(parseFloat(n)) && isFinite(+n);
}
function isObjOrArrayOrRegExp(env: closure.Entry): boolean {
return env.object !== undefined || env.array !== undefined || env.regexp !== undefined;
}
function deepContainsObjOrArrayOrRegExp(env: closure.Entry): boolean {
return (
isObjOrArrayOrRegExp(env) ||
(env.output !== undefined && deepContainsObjOrArrayOrRegExp(env.output)) ||
(env.promise !== undefined && deepContainsObjOrArrayOrRegExp(env.promise))
);
}
/**
* Converts an environment object into a string which can be embedded into a
* serialized function body. Note that this is not JSON serialization, as we
* may have property values which are variable references to other global
* functions. In other words, there can be free variables in the resulting
* object literal.
*
* @param envObj
* The environment object to convert to a string.
*/
function envObjToString(envObj: Record<string, string>): string {
return `{ ${Object.keys(envObj)
.map((k) => `${k}: ${envObj[k]}`)
.join(", ")} }`;
}
/**
* An identifier to be imported into a serialised function.
*/
interface ImportedIdentifier {
/**
* True if and only if the identifier to be imported would shadow a reserved
* identifier (e.g. "exports").
*/
reserved: boolean;
/**
* The identifier required by serialised function code.
*/
identifier: string;
/**
* An alias for the required identifier that doesn't clash with reserved
* identifiers. May be the required identifier itself if it doesn't clash.
*/
as: string;
}
/**
* Computes an appropriate {@link ImportedIdentifier} for a given identifier.
*/
function importIdentifier(identifier: string): ImportedIdentifier {
if (RESERVED_IDENTIFIERS.has(identifier)) {
const as = `__pulumi_closure_import_${identifier}`;
return {
reserved: true,
identifier,
as,
};
}
return {
reserved: false,
identifier,
as: identifier,
};
}
/**
* The set of known reserved identifiers that we might encounter when
* serialising function code.
*
* @internal
*/
const RESERVED_IDENTIFIERS = new Set(["exports"]);