| /* |
| * Copyright 2017-2018 IBM 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. |
| */ |
| |
| function main() { |
| 'use strict' |
| |
| const fs = require('fs') |
| const os = require('os') |
| const path = require('path') |
| const semver = require('semver') |
| const util = require('util') |
| |
| // read composer version number |
| const version = require('./package.json').version |
| |
| const isObject = obj => typeof obj === 'object' && obj !== null && !Array.isArray(obj) |
| |
| // combinator signatures |
| const combinators = {} |
| |
| // error class |
| class ComposerError extends Error { |
| constructor(message, argument) { |
| super(message + (argument !== undefined ? '\nArgument: ' + util.inspect(argument) : '')) |
| } |
| } |
| |
| // registered plugins |
| const plugins = [] |
| |
| const composer = {} |
| Object.assign(composer, { |
| // detect task type and create corresponding composition object |
| task(task) { |
| if (arguments.length > 1) throw new ComposerError('Too many arguments') |
| if (task === null) return composer.empty() |
| if (task instanceof Composition) return task |
| if (typeof task === 'function') return composer.function(task) |
| if (typeof task === 'string') return composer.action(task) |
| throw new ComposerError('Invalid argument', task) |
| }, |
| |
| // function combinator: stringify function code |
| function(fun) { |
| if (arguments.length > 1) throw new ComposerError('Too many arguments') |
| if (typeof fun === 'function') { |
| fun = `${fun}` |
| if (fun.indexOf('[native code]') !== -1) throw new ComposerError('Cannot capture native function', fun) |
| } |
| if (typeof fun === 'string') { |
| fun = { kind: 'nodejs:default', code: fun } |
| } |
| if (!isObject(fun)) throw new ComposerError('Invalid argument', fun) |
| return new Composition({ type: 'function', function: { exec: fun } }) |
| }, |
| |
| // action combinator |
| action(name, options = {}) { |
| if (arguments.length > 2) throw new ComposerError('Too many arguments') |
| if (!isObject(options)) throw new ComposerError('Invalid argument', options) |
| name = composer.util.canonical(name) // throws ComposerError if name is not valid |
| let exec |
| if (Array.isArray(options.sequence)) { // native sequence |
| exec = { kind: 'sequence', components: options.sequence.map(canonical) } |
| } else if (typeof options.filename === 'string') { // read action code from file |
| exec = fs.readFileSync(options.filename, { encoding: 'utf8' }) |
| } else if (typeof options.action === 'function') { // capture function |
| exec = `const main = ${options.action}` |
| if (exec.indexOf('[native code]') !== -1) throw new ComposerError('Cannot capture native function', options.action) |
| } else if (typeof options.action === 'string' || isObject(options.action)) { |
| exec = options.action |
| } |
| if (typeof exec === 'string') { |
| exec = { kind: 'nodejs:default', code: exec } |
| } |
| const composition = { type: 'action', name } |
| if (exec) composition.action = { exec } |
| return new Composition(composition) |
| }, |
| }) |
| |
| const lowerer = { |
| empty() { |
| return composer.sequence() |
| }, |
| |
| seq({ components }) { |
| return composer.sequence(...components) |
| }, |
| |
| value({ value }) { |
| return composer.literal(value) |
| }, |
| |
| literal({ value }) { |
| return composer.let({ value }, composer.function('() => value')) |
| }, |
| |
| retain({ components }) { |
| return composer.let( |
| { params: null }, |
| composer.finally( |
| args => { params = args }, |
| composer.seq(composer.mask(...components), |
| result => ({ params, result })))) |
| }, |
| |
| retain_catch({ components }) { |
| return composer.seq( |
| composer.retain( |
| composer.finally( |
| composer.seq(...components), |
| result => ({ result }))), |
| ({ params, result }) => ({ params, result: result.result })) |
| }, |
| |
| if({ test, consequent, alternate }) { |
| return composer.let( |
| { params: null }, |
| composer.finally( |
| args => { params = args }, |
| composer.if_nosave( |
| composer.mask(test), |
| composer.finally(() => params, composer.mask(consequent)), |
| composer.finally(() => params, composer.mask(alternate))))) |
| }, |
| |
| while({ test, body }) { |
| return composer.let( |
| { params: null }, |
| composer.finally( |
| args => { params = args }, |
| composer.seq(composer.while_nosave( |
| composer.mask(test), |
| composer.finally(() => params, composer.seq(composer.mask(body), args => { params = args }))), |
| () => params))) |
| }, |
| |
| dowhile({ body, test }) { |
| return composer.let( |
| { params: null }, |
| composer.finally( |
| args => { params = args }, |
| composer.seq(composer.dowhile_nosave( |
| composer.finally(() => params, composer.seq(composer.mask(body), args => { params = args })), |
| composer.mask(test)), |
| () => params))) |
| }, |
| |
| repeat({ count, components }) { |
| return composer.let( |
| { count }, |
| composer.while( |
| composer.function('() => count-- > 0'), |
| composer.mask(...components))) |
| }, |
| |
| retry({ count, components }) { |
| return composer.let( |
| { count }, |
| params => ({ params }), |
| composer.dowhile( |
| composer.finally(({ params }) => params, composer.mask(composer.retain_catch(...components))), |
| composer.function('({ result }) => result.error !== undefined && count-- > 0')), |
| ({ result }) => result) |
| }, |
| } |
| |
| // recursively flatten composition into { composition, actions } by extracting embedded action definitions |
| function flatten(composition) { |
| if (arguments.length > 1) throw new ComposerError('Too many arguments') |
| if (!(composition instanceof Composition)) throw new ComposerError('Invalid argument', composition) |
| |
| const actions = [] |
| |
| const flatten = composition => { |
| composition = new Composition(composition) // copy |
| composition.visit(flatten) |
| if (composition.type === 'action' && composition.action) { |
| actions.push({ name: composition.name, action: composition.action }) |
| delete composition.action |
| } |
| return composition |
| } |
| |
| composition = flatten(composition) |
| return { composition, actions } |
| } |
| |
| // synthesize composition code |
| function synthesize(composition) { |
| if (arguments.length > 1) throw new ComposerError('Too many arguments') |
| if (!(composition instanceof Composition)) throw new ComposerError('Invalid argument', composition) |
| let code = `const main=(${main})().runtime(` |
| for (let plugin of plugins) { |
| code += `{plugin:new(${plugin.constructor})()` |
| if (plugin.configure) code += `,config:${JSON.stringify(plugin.configure())}` |
| code += '},' |
| } |
| code = require('uglify-es').minify(`${code})`, { output: { max_line_len: 127 } }).code |
| code = `// generated by composer v${version}\n\nconst composition = ${JSON.stringify(composition, null, 4)}\n\n// do not edit below this point\n\n${code}` // invoke conductor on composition |
| return { exec: { kind: 'nodejs:default', code }, annotations: [{ key: 'conductor', value: composition }, { key: 'composer', value: version }] } |
| } |
| |
| composer.util = { |
| // return the signatures of the combinators |
| get combinators() { |
| return combinators |
| }, |
| |
| // recursively deserialize composition |
| deserialize(composition) { |
| if (arguments.length > 1) throw new ComposerError('Too many arguments') |
| composition = new Composition(composition) // copy |
| composition.visit(composition => composer.util.deserialize(composition)) |
| return composition |
| }, |
| |
| // recursively lower combinators to the desired set of combinators (including primitive combinators) |
| lower(composition, combinators = []) { |
| if (arguments.length > 2) throw new ComposerError('Too many arguments') |
| if (!(composition instanceof Composition)) throw new ComposerError('Invalid argument', composition) |
| if (typeof combinators === 'string') { // lower to combinators of specific composer version |
| combinators = Object.keys(composer.util.combinators).filter(key => semver.gte(combinators, composer.util.combinators[key].since)) |
| } |
| if (!Array.isArray(combinators)) throw new ComposerError('Invalid argument', combinators) |
| |
| const lower = composition => { |
| composition = new Composition(composition) // copy |
| // repeatedly lower root combinator |
| while (combinators.indexOf(composition.type) < 0 && lowerer[composition.type]) { |
| const path = composition.path |
| composition = lowerer[composition.type](composition) |
| if (path !== undefined) composition.path = path // preserve path |
| } |
| // lower nested combinators |
| composition.visit(lower) |
| return composition |
| } |
| |
| return lower(composition) |
| }, |
| |
| // register plugin |
| register(plugin) { |
| if (plugin.combinators) init(plugin.combinators()) |
| if (plugin.composer) Object.assign(composer, plugin.composer({ composer, ComposerError, Composition })) |
| if (plugin.lowerer) Object.assign(lowerer, plugin.lowerer({ composer, ComposerError, Composition })) |
| plugins.push(plugin) |
| return composer |
| }, |
| |
| /** |
| * Parses a (possibly fully qualified) resource name and validates it. If it's not a fully qualified name, |
| * then attempts to qualify it. |
| * |
| * Examples string to namespace, [package/]action name |
| * foo => /_/foo |
| * pkg/foo => /_/pkg/foo |
| * /ns/foo => /ns/foo |
| * /ns/pkg/foo => /ns/pkg/foo |
| */ |
| canonical(name) { |
| if (typeof name !== 'string') throw new ComposerError('Name must be a string') |
| if (name.trim().length == 0) throw new ComposerError('Name is not valid') |
| name = name.trim() |
| const delimiter = '/' |
| const parts = name.split(delimiter) |
| const n = parts.length |
| const leadingSlash = name[0] == delimiter |
| // no more than /ns/p/a |
| if (n < 1 || n > 4 || (leadingSlash && n == 2) || (!leadingSlash && n == 4)) throw new ComposerError('Name is not valid') |
| // skip leading slash, all parts must be non empty (could tighten this check to match EntityName regex) |
| parts.forEach(function (part, i) { if (i > 0 && part.trim().length == 0) throw new ComposerError('Name is not valid') }) |
| const newName = parts.join(delimiter) |
| if (leadingSlash) return newName |
| else if (n < 3) return `${delimiter}_${delimiter}${newName}` |
| else return `${delimiter}${newName}` |
| }, |
| |
| // encode composition as an action table |
| encode(name, composition, combinators) { |
| if (arguments.length > 3) throw new ComposerError('Too many arguments') |
| name = composer.util.canonical(name) // throws ComposerError if name is not valid |
| if (!(composition instanceof Composition)) throw new ComposerError('Invalid argument', composition) |
| if (combinators) composition = composer.util.lower(composition, combinators) |
| const table = flatten(composition) |
| table.actions.push({ name, action: synthesize(table.composition) }) |
| return table.actions |
| }, |
| |
| // return composer version |
| get version() { |
| return version |
| }, |
| |
| // return enhanced openwhisk client capable of deploying compositions |
| openwhisk(options) { |
| // try to extract apihost and key first from whisk property file file and then from process.env |
| let apihost |
| let api_key |
| |
| try { |
| const wskpropsPath = process.env.WSK_CONFIG_FILE || path.join(os.homedir(), '.wskprops') |
| const lines = fs.readFileSync(wskpropsPath, { encoding: 'utf8' }).split('\n') |
| |
| for (let line of lines) { |
| let parts = line.trim().split('=') |
| if (parts.length === 2) { |
| if (parts[0] === 'APIHOST') { |
| apihost = parts[1] |
| } else if (parts[0] === 'AUTH') { |
| api_key = parts[1] |
| } |
| } |
| } |
| } catch (error) { } |
| |
| if (process.env.__OW_API_HOST) apihost = process.env.__OW_API_HOST |
| if (process.env.__OW_API_KEY) api_key = process.env.__OW_API_KEY |
| |
| const wsk = require('openwhisk')(Object.assign({ apihost, api_key }, options)) |
| wsk.compositions = new Compositions(wsk) |
| return wsk |
| }, |
| } |
| |
| // composition class |
| class Composition { |
| // weaker instanceof to tolerate multiple instances of this class |
| static [Symbol.hasInstance](instance) { |
| return instance.constructor && instance.constructor.name === Composition.name |
| } |
| |
| // construct a composition object with the specified fields |
| constructor(composition) { |
| if (!isObject(composition) || composer.util.combinators[composition.type] === undefined) throw new ComposerError('Invalid argument', composition) |
| const combinator = composer.util.combinators[composition.type] |
| if (combinator.components && composition.components === undefined)throw new ComposerError('Invalid argument', composition) |
| for (let arg of combinator.args || []) { |
| if (!arg.optional && composition[arg._] === undefined) throw new ComposerError('Invalid argument', composition) |
| } |
| return Object.assign(this, composition) |
| } |
| |
| // apply f to all fields of type composition |
| visit(f) { |
| const combinator = composer.util.combinators[this.type] |
| if (combinator.components) { |
| this.components = this.components.map(f) |
| } |
| for (let arg of combinator.args || []) { |
| if (arg.type === undefined && this[arg._] !== undefined) { |
| this[arg._] = f(this[arg._], arg._) |
| } |
| } |
| } |
| } |
| |
| // derive combinator methods from combinator table |
| function init(combinators) { |
| Object.assign(composer.util.combinators, combinators) |
| for (let type in combinators) { |
| const combinator = combinators[type] |
| // do not overwrite existing combinators |
| composer[type] = composer[type] || function () { |
| const composition = { type } |
| const skip = combinator.args && combinator.args.length || 0 |
| if (!combinator.components && (arguments.length > skip)) { |
| throw new ComposerError('Too many arguments') |
| } |
| for (let i = 0; i < skip; ++i) { |
| const arg = combinator.args[i] |
| const argument = arguments[i] |
| if (argument === undefined && arg.optional && arg.type !== undefined) continue |
| switch (arg.type) { |
| case undefined: |
| composition[arg._] = composer.task(arg.optional ? argument || null : argument) |
| continue |
| case 'value': |
| if (typeof argument === 'function') throw new ComposerError('Invalid argument', argument) |
| composition[arg._] = argument === undefined ? {} : argument |
| continue |
| case 'object': |
| if (argument === null || Array.isArray(argument)) throw new ComposerError('Invalid argument', argument) |
| default: |
| if (typeof argument !== arg.type) throw new ComposerError('Invalid argument', argument) |
| composition[arg._] = argument |
| } |
| } |
| if (combinator.components) { |
| composition.components = Array.prototype.slice.call(arguments, skip).map(obj => composer.task(obj)) |
| } |
| return new Composition(composition) |
| } |
| } |
| } |
| |
| init({ |
| empty: { since: '0.4.0' }, |
| seq: { components: true, since: '0.4.0' }, |
| sequence: { components: true, since: '0.4.0' }, |
| if: { args: [{ _: 'test' }, { _: 'consequent' }, { _: 'alternate', optional: true }], since: '0.4.0' }, |
| if_nosave: { args: [{ _: 'test' }, { _: 'consequent' }, { _: 'alternate', optional: true }], since: '0.4.0' }, |
| while: { args: [{ _: 'test' }, { _: 'body' }], since: '0.4.0' }, |
| while_nosave: { args: [{ _: 'test' }, { _: 'body' }], since: '0.4.0' }, |
| dowhile: { args: [{ _: 'body' }, { _: 'test' }], since: '0.4.0' }, |
| dowhile_nosave: { args: [{ _: 'body' }, { _: 'test' }], since: '0.4.0' }, |
| try: { args: [{ _: 'body' }, { _: 'handler' }], since: '0.4.0' }, |
| finally: { args: [{ _: 'body' }, { _: 'finalizer' }], since: '0.4.0' }, |
| retain: { components: true, since: '0.4.0' }, |
| retain_catch: { components: true, since: '0.4.0' }, |
| let: { args: [{ _: 'declarations', type: 'object' }], components: true, since: '0.4.0' }, |
| mask: { components: true, since: '0.4.0' }, |
| action: { args: [{ _: 'name', type: 'string' }, { _: 'action', type: 'object', optional: true }], since: '0.4.0' }, |
| repeat: { args: [{ _: 'count', type: 'number' }], components: true, since: '0.4.0' }, |
| retry: { args: [{ _: 'count', type: 'number' }], components: true, since: '0.4.0' }, |
| value: { args: [{ _: 'value', type: 'value' }], since: '0.4.0' }, |
| literal: { args: [{ _: 'value', type: 'value' }], since: '0.4.0' }, |
| function: { args: [{ _: 'function', type: 'object' }], since: '0.4.0' }, |
| async: { args: [{ _: 'body' }], since: '0.6.0' }, |
| }) |
| |
| // management class for compositions |
| class Compositions { |
| constructor(wsk) { |
| this.actions = wsk.actions |
| } |
| |
| deploy(name, composition, combinators) { |
| const actions = composer.util.encode(name, composition, combinators) |
| return actions.reduce((promise, action) => promise.then(() => this.actions.delete(action).catch(() => { })) |
| .then(() => this.actions.update(action)), Promise.resolve()) |
| .then(() => actions) |
| } |
| } |
| |
| // runtime stuff |
| function runtime() { |
| // recursively label combinators with the json path |
| function label(composition) { |
| if (arguments.length > 1) throw new ComposerError('Too many arguments') |
| if (!(composition instanceof Composition)) throw new ComposerError('Invalid argument', composition) |
| |
| const label = path => (composition, name, array) => { |
| composition = new Composition(composition) // copy |
| composition.path = path + (name !== undefined ? (array === undefined ? `.${name}` : `[${name}]`) : '') |
| // label nested combinators |
| composition.visit(label(composition.path)) |
| return composition |
| } |
| |
| return label('')(composition) |
| } |
| |
| // compile ast to fsm |
| const compiler = { |
| sequence(node) { |
| return [{ type: 'pass', path: node.path }, ...compile(...node.components)] |
| }, |
| |
| action(node) { |
| return [{ type: 'action', name: node.name, path: node.path }] |
| }, |
| |
| async(node) { |
| const body = compile(node.body) |
| return [{ type: 'async', path: node.path, return: body.length + 2 }, ...body, { type: 'stop' }, { type: 'pass' }] |
| }, |
| |
| function(node) { |
| return [{ type: 'function', exec: node.function.exec, path: node.path }] |
| }, |
| |
| finally(node) { |
| const finalizer = compile(node.finalizer) |
| const fsm = [{ type: 'try', path: node.path }, ...compile(node.body), { type: 'exit' }, ...finalizer] |
| fsm[0].catch = fsm.length - finalizer.length |
| return fsm |
| }, |
| |
| let(node) { |
| return [{ type: 'let', let: node.declarations, path: node.path }, ...compile(...node.components), { type: 'exit' }] |
| }, |
| |
| mask(node) { |
| return [{ type: 'let', let: null, path: node.path }, ...compile(...node.components), { type: 'exit' }] |
| }, |
| |
| try(node) { |
| const handler = [...compile(node.handler), { type: 'pass' }] |
| const fsm = [{ type: 'try', path: node.path }, ...compile(node.body), { type: 'exit' }, ...handler] |
| fsm[0].catch = fsm.length - handler.length |
| fsm[fsm.length - handler.length - 1].next = handler.length |
| return fsm |
| }, |
| |
| if_nosave(node) { |
| const consequent = compile(node.consequent) |
| const alternate = [...compile(node.alternate), { type: 'pass' }] |
| const fsm = [{ type: 'pass', path: node.path }, ...compile(node.test), { type: 'choice', then: 1, else: consequent.length + 1 }, ...consequent, ...alternate] |
| fsm[fsm.length - alternate.length - 1].next = alternate.length |
| return fsm |
| }, |
| |
| while_nosave(node) { |
| const body = compile(node.body) |
| const fsm = [{ type: 'pass', path: node.path }, ...compile(node.test), { type: 'choice', then: 1, else: body.length + 1 }, ...body, { type: 'pass' }] |
| fsm[fsm.length - 2].next = 2 - fsm.length |
| return fsm |
| }, |
| |
| dowhile_nosave(node) { |
| const fsm = [{ type: 'pass', path: node.path }, ...compile(node.body), ...compile(node.test), { type: 'choice', else: 1 }, { type: 'pass' }] |
| fsm[fsm.length - 2].then = 2 - fsm.length |
| return fsm |
| }, |
| } |
| |
| function compile(node) { |
| if (arguments.length === 0) return [{ type: 'empty' }] |
| if (arguments.length === 1) return compiler[node.type](node) |
| return Array.prototype.reduce.call(arguments, (fsm, node) => { fsm.push(...compile(node)); return fsm }, []) |
| } |
| |
| const openwhisk = require('openwhisk') |
| let wsk |
| |
| const conductor = { |
| choice({ p, node, index }) { |
| p.s.state = index + (p.params.value ? node.then : node.else) |
| }, |
| |
| try({ p, node, index }) { |
| p.s.stack.unshift({ catch: index + node.catch }) |
| }, |
| |
| let({ p, node, index }) { |
| p.s.stack.unshift({ let: JSON.parse(JSON.stringify(node.let)) }) |
| }, |
| |
| exit({ p, node, index }) { |
| if (p.s.stack.length === 0) return internalError(`State ${index} attempted to pop from an empty stack`) |
| p.s.stack.shift() |
| }, |
| |
| action({ p, node, index }) { |
| return { action: node.name, params: p.params, state: { $resume: p.s } } |
| }, |
| |
| function({ p, node, index }) { |
| return Promise.resolve().then(() => run(node.exec.code, p)) |
| .catch(error => { |
| console.error(error) |
| return { error: `An exception was caught at state ${index} (see log for details)` } |
| }) |
| .then(result => { |
| if (typeof result === 'function') result = { error: `State ${index} evaluated to a function` } |
| // if a function has only side effects and no return value, return params |
| p.params = JSON.parse(JSON.stringify(result === undefined ? p.params : result)) |
| inspect(p) |
| return step(p) |
| }) |
| }, |
| |
| empty({ p, node, index }) { |
| inspect(p) |
| }, |
| |
| pass({ p, node, index }) { |
| }, |
| |
| async({ p, node, index, inspect, step }) { |
| if (!wsk) wsk = openwhisk({ ignore_certs: true }) |
| p.params.$resume = { state: p.s.state } |
| p.s.state = index + node.return |
| return wsk.actions.invoke({ name: process.env.__OW_ACTION_NAME, params: p.params }) |
| .catch(error => { |
| console.error(error) |
| return { error: `An exception was caught at state ${index} (see log for details)` } |
| }) |
| .then(result => { |
| p.params = result |
| inspect(p) |
| return step(p) |
| }) |
| }, |
| |
| stop({ p, node, index, inspect, step }) { |
| p.s.state = -1 |
| }, |
| } |
| |
| const finishers = [] |
| |
| for (let { plugin, config } of arguments) { |
| composer.util.register(plugin) |
| if (plugin.compiler) Object.assign(compiler, plugin.compiler({ compile })) |
| if (plugin.conductor) { |
| Object.assign(conductor, plugin.conductor(config)) |
| if (conductor._finish) { |
| finishers.push(conductor._finish) |
| delete conductor._finish |
| } |
| } |
| } |
| |
| const fsm = compile(composer.util.lower(label(composer.util.deserialize(composition)))) |
| |
| // encode error object |
| const encodeError = error => ({ |
| code: typeof error.code === 'number' && error.code || 500, |
| error: (typeof error.error === 'string' && error.error) || error.message || (typeof error === 'string' && error) || 'An internal error occurred' |
| }) |
| |
| // error status codes |
| const badRequest = error => Promise.reject({ code: 400, error }) |
| const internalError = error => Promise.reject(encodeError(error)) |
| |
| // wrap params if not a dictionary, branch to error handler if error |
| function inspect(p) { |
| if (!isObject(p.params)) p.params = { value: p.params } |
| if (p.params.error !== undefined) { |
| p.params = { error: p.params.error } // discard all fields but the error field |
| p.s.state = -1 // abort unless there is a handler in the stack |
| while (p.s.stack.length > 0) { |
| if ((p.s.state = p.s.stack.shift().catch || -1) >= 0) break |
| } |
| } |
| } |
| |
| // run function f on current stack |
| function run(f, p) { |
| // handle let/mask pairs |
| const view = [] |
| let n = 0 |
| for (let frame of p.s.stack) { |
| if (frame.let === null) { |
| n++ |
| } else if (frame.let !== undefined) { |
| if (n === 0) { |
| view.push(frame) |
| } else { |
| n-- |
| } |
| } |
| } |
| |
| // update value of topmost matching symbol on stack if any |
| function set(symbol, value) { |
| const element = view.find(element => element.let !== undefined && element.let[symbol] !== undefined) |
| if (element !== undefined) element.let[symbol] = JSON.parse(JSON.stringify(value)) |
| } |
| |
| // collapse stack for invocation |
| const env = view.reduceRight((acc, cur) => cur.let ? Object.assign(acc, cur.let) : acc, {}) |
| let main = '(function(){try{' |
| for (const name in env) main += `var ${name}=arguments[1]['${name}'];` |
| main += `return eval((${f}))(arguments[0])}finally{` |
| for (const name in env) main += `arguments[1]['${name}']=${name};` |
| main += '}})' |
| try { |
| return (1, eval)(main)(p.params, env) |
| } finally { |
| for (const name in env) set(name, env[name]) |
| } |
| } |
| |
| function step(p) { |
| // final state, return composition result |
| if (p.s.state < 0 || p.s.state >= fsm.length) { |
| console.log(`Entering final state`) |
| console.log(JSON.stringify(p.params)) |
| return finishers.reduce((promise, _finish) => promise.then(() => _finish(p)), Promise.resolve()) |
| .then(() => p.params.error ? p.params : { params: p.params }) |
| } |
| |
| // process one state |
| const node = fsm[p.s.state] // json definition for index state |
| if (node.path !== undefined) console.log(`Entering composition${node.path}`) |
| const index = p.s.state // current state |
| p.s.state = p.s.state + (node.next || 1) // default next state |
| return conductor[node.type]({ p, index, node, inspect, step }) || step(p) |
| } |
| |
| return params => Promise.resolve().then(() => invoke(params)).catch(internalError) |
| |
| // do invocation |
| function invoke(params) { |
| const p = { s: { state: 0, stack: [] }, params } // initial state |
| |
| if (params.$resume !== undefined) { |
| if (!isObject(params.$resume)) return badRequest('The type of optional $resume parameter must be object') |
| const resuming = params.$resume.stack |
| Object.assign(p.s, params.$resume) |
| if (typeof p.s.state !== 'number') return badRequest('The type of optional $resume.state parameter must be number') |
| if (!Array.isArray(p.s.stack)) return badRequest('The type of optional $resume.stack parameter must be an array') |
| delete params.$resume |
| if (resuming) inspect(p) // handle error objects when resuming |
| } |
| |
| return step(p) |
| } |
| } |
| |
| return { composer, runtime } |
| } |
| |
| module.exports = main().composer |
