/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
class HookCodeFactory {
constructor(config) {
this.config = config;
this.options = undefined;
this._args = undefined;
}
create(options) {
this.init(options);
let fn;
switch (this.options.type) {
case "sync":
fn = new Function(
this.args(),
'"use strict";\n' +
this.header() +
this.contentWithInterceptors({
onError: err => `throw ${err};\n`,
onResult: result => `return ${result};\n`,
resultReturns: true,
onDone: () => "",
rethrowIfPossible: true
})
);
break;
case "async":
fn = new Function(
this.args({
after: "_callback"
}),
'"use strict";\n' +
this.header() +
this.contentWithInterceptors({
onError: err => `_callback(${err});\n`,
onResult: result => `_callback(null, ${result});\n`,
onDone: () => "_callback();\n"
})
);
break;
case "promise":
let errorHelperUsed = false;
const content = this.contentWithInterceptors({
onError: err => {
errorHelperUsed = true;
return `_error(${err});\n`;
},
onResult: result => `_resolve(${result});\n`,
onDone: () => "_resolve();\n"
});
let code = "";
code += '"use strict";\n';
code += this.header();
code += "return new Promise((function(_resolve, _reject) {\n";
if (errorHelperUsed) {
code += "var _sync = true;\n";
code += "function _error(_err) {\n";
code += "if(_sync)\n";
code +=
"_resolve(Promise.resolve().then((function() { throw _err; })));\n";
code += "else\n";
code += "_reject(_err);\n";
code += "};\n";
}
code += content;
if (errorHelperUsed) {
code += "_sync = false;\n";
}
code += "}));\n";
fn = new Function(this.args(), code);
break;
}
this.deinit();
return fn;
}
setup(instance, options) {
instance._x = options.taps.map(t => t.fn);
}
/**
* @param {{ type: "sync" | "promise" | "async", taps: Array<Tap>, interceptors: Array<Interceptor> }} options
*/
init(options) {
this.options = options;
this._args = options.args.slice();
}
deinit() {
this.options = undefined;
this._args = undefined;
}
contentWithInterceptors(options) {
if (this.options.interceptors.length > 0) {
const onError = options.onError;
const onResult = options.onResult;
const onDone = options.onDone;
let code = "";
for (let i = 0; i < this.options.interceptors.length; i++) {
const interceptor = this.options.interceptors[i];
if (interceptor.call) {
code += `${this.getInterceptor(i)}.call(${this.args({
before: interceptor.context ? "_context" : undefined
})});\n`;
}
}
code += this.content(
Object.assign(options, {
onError:
onError &&
(err => {
let code = "";
for (let i = 0; i < this.options.interceptors.length; i++) {
const interceptor = this.options.interceptors[i];
if (interceptor.error) {
code += `${this.getInterceptor(i)}.error(${err});\n`;
}
}
code += onError(err);
return code;
}),
onResult:
onResult &&
(result => {
let code = "";
for (let i = 0; i < this.options.interceptors.length; i++) {
const interceptor = this.options.interceptors[i];
if (interceptor.result) {
code += `${this.getInterceptor(i)}.result(${result});\n`;
}
}
code += onResult(result);
return code;
}),
onDone:
onDone &&
(() => {
let code = "";
for (let i = 0; i < this.options.interceptors.length; i++) {
const interceptor = this.options.interceptors[i];
if (interceptor.done) {
code += `${this.getInterceptor(i)}.done();\n`;
}
}
code += onDone();
return code;
})
})
);
return code;
} else {
return this.content(options);
}
}
header() {
let code = "";
if (this.needContext()) {
code += "var _context = {};\n";
} else {
code += "var _context;\n";
}
code += "var _x = this._x;\n";
if (this.options.interceptors.length > 0) {
code += "var _taps = this.taps;\n";
code += "var _interceptors = this.interceptors;\n";
}
return code;
}
needContext() {
for (const tap of this.options.taps) if (tap.context) return true;
return false;
}
callTap(tapIndex, { onError, onResult, onDone, rethrowIfPossible }) {
let code = "";
let hasTapCached = false;
for (let i = 0; i < this.options.interceptors.length; i++) {
const interceptor = this.options.interceptors[i];
if (interceptor.tap) {
if (!hasTapCached) {
code += `var _tap${tapIndex} = ${this.getTap(tapIndex)};\n`;
hasTapCached = true;
}
code += `${this.getInterceptor(i)}.tap(${
interceptor.context ? "_context, " : ""
}_tap${tapIndex});\n`;
}
}
code += `var _fn${tapIndex} = ${this.getTapFn(tapIndex)};\n`;
const tap = this.options.taps[tapIndex];
switch (tap.type) {
case "sync":
if (!rethrowIfPossible) {
code += `var _hasError${tapIndex} = false;\n`;
code += "try {\n";
}
if (onResult) {
code += `var _result${tapIndex} = _fn${tapIndex}(${this.args({
before: tap.context ? "_context" : undefined
})});\n`;
} else {
code += `_fn${tapIndex}(${this.args({
before: tap.context ? "_context" : undefined
})});\n`;
}
if (!rethrowIfPossible) {
code += "} catch(_err) {\n";
code += `_hasError${tapIndex} = true;\n`;
code += onError("_err");
code += "}\n";
code += `if(!_hasError${tapIndex}) {\n`;
}
if (onResult) {
code += onResult(`_result${tapIndex}`);
}
if (onDone) {
code += onDone();
}
if (!rethrowIfPossible) {
code += "}\n";
}
break;
case "async":
let cbCode = "";
if (onResult)
cbCode += `(function(_err${tapIndex}, _result${tapIndex}) {\n`;
else cbCode += `(function(_err${tapIndex}) {\n`;
cbCode += `if(_err${tapIndex}) {\n`;
cbCode += onError(`_err${tapIndex}`);
cbCode += "} else {\n";
if (onResult) {
cbCode += onResult(`_result${tapIndex}`);
}
if (onDone) {
cbCode += onDone();
}
cbCode += "}\n";
cbCode += "})";
code += `_fn${tapIndex}(${this.args({
before: tap.context ? "_context" : undefined,
after: cbCode
})});\n`;
break;
case "promise":
code += `var _hasResult${tapIndex} = false;\n`;
code += `var _promise${tapIndex} = _fn${tapIndex}(${this.args({
before: tap.context ? "_context" : undefined
})});\n`;
code += `if (!_promise${tapIndex} || !_promise${tapIndex}.then)\n`;
code += ` throw new Error('Tap function (tapPromise) did not return promise (returned ' + _promise${tapIndex} + ')');\n`;
code += `_promise${tapIndex}.then((function(_result${tapIndex}) {\n`;
code += `_hasResult${tapIndex} = true;\n`;
if (onResult) {
code += onResult(`_result${tapIndex}`);
}
if (onDone) {
code += onDone();
}
code += `}), function(_err${tapIndex}) {\n`;
code += `if(_hasResult${tapIndex}) throw _err${tapIndex};\n`;
code += onError(`_err${tapIndex}`);
code += "});\n";
break;
}
return code;
}
callTapsSeries({
onError,
onResult,
resultReturns,
onDone,
doneReturns,
rethrowIfPossible
}) {
if (this.options.taps.length === 0) return onDone();
const firstAsync = this.options.taps.findIndex(t => t.type !== "sync");
const somethingReturns = resultReturns || doneReturns;
let code = "";
let current = onDone;
let unrollCounter = 0;
for (let j = this.options.taps.length - 1; j >= 0; j--) {
const i = j;
const unroll =
current !== onDone &&
(this.options.taps[i].type !== "sync" || unrollCounter++ > 20);
if (unroll) {
unrollCounter = 0;
code += `function _next${i}() {\n`;
code += current();
code += `}\n`;
current = () => `${somethingReturns ? "return " : ""}_next${i}();\n`;
}
const done = current;
const doneBreak = skipDone => {
if (skipDone) return "";
return onDone();
};
const content = this.callTap(i, {
onError: error => onError(i, error, done, doneBreak),
onResult:
onResult &&
(result => {
return onResult(i, result, done, doneBreak);
}),
onDone: !onResult && done,
rethrowIfPossible:
rethrowIfPossible && (firstAsync < 0 || i < firstAsync)
});
current = () => content;
}
code += current();
return code;
}
callTapsLooping({ onError, onDone, rethrowIfPossible }) {
if (this.options.taps.length === 0) return onDone();
const syncOnly = this.options.taps.every(t => t.type === "sync");
let code = "";
if (!syncOnly) {
code += "var _looper = (function() {\n";
code += "var _loopAsync = false;\n";
}
code += "var _loop;\n";
code += "do {\n";
code += "_loop = false;\n";
for (let i = 0; i < this.options.interceptors.length; i++) {
const interceptor = this.options.interceptors[i];
if (interceptor.loop) {
code += `${this.getInterceptor(i)}.loop(${this.args({
before: interceptor.context ? "_context" : undefined
})});\n`;
}
}
code += this.callTapsSeries({
onError,
onResult: (i, result, next, doneBreak) => {
let code = "";
code += `if(${result} !== undefined) {\n`;
code += "_loop = true;\n";
if (!syncOnly) code += "if(_loopAsync) _looper();\n";
code += doneBreak(true);
code += `} else {\n`;
code += next();
code += `}\n`;
return code;
},
onDone:
onDone &&
(() => {
let code = "";
code += "if(!_loop) {\n";
code += onDone();
code += "}\n";
return code;
}),
rethrowIfPossible: rethrowIfPossible && syncOnly
});
code += "} while(_loop);\n";
if (!syncOnly) {
code += "_loopAsync = true;\n";
code += "});\n";
code += "_looper();\n";
}
return code;
}
callTapsParallel({
onError,
onResult,
onDone,
rethrowIfPossible,
onTap = (i, run) => run()
}) {
if (this.options.taps.length <= 1) {
return this.callTapsSeries({
onError,
onResult,
onDone,
rethrowIfPossible
});
}
let code = "";
code += "do {\n";
code += `var _counter = ${this.options.taps.length};\n`;
if (onDone) {
code += "var _done = (function() {\n";
code += onDone();
code += "});\n";
}
for (let i = 0; i < this.options.taps.length; i++) {
const done = () => {
if (onDone) return "if(--_counter === 0) _done();\n";
else return "--_counter;";
};
const doneBreak = skipDone => {
if (skipDone || !onDone) return "_counter = 0;\n";
else return "_counter = 0;\n_done();\n";
};
code += "if(_counter <= 0) break;\n";
code += onTap(
i,
() =>
this.callTap(i, {
onError: error => {
let code = "";
code += "if(_counter > 0) {\n";
code += onError(i, error, done, doneBreak);
code += "}\n";
return code;
},
onResult:
onResult &&
(result => {
let code = "";
code += "if(_counter > 0) {\n";
code += onResult(i, result, done, doneBreak);
code += "}\n";
return code;
}),
onDone:
!onResult &&
(() => {
return done();
}),
rethrowIfPossible
}),
done,
doneBreak
);
}
code += "} while(false);\n";
return code;
}
args({ before, after } = {}) {
let allArgs = this._args;
if (before) allArgs = [before].concat(allArgs);
if (after) allArgs = allArgs.concat(after);
if (allArgs.length === 0) {
return "";
} else {
return allArgs.join(", ");
}
}
getTapFn(idx) {
return `_x[${idx}]`;
}
getTap(idx) {
return `_taps[${idx}]`;
}
getInterceptor(idx) {
return `_interceptors[${idx}]`;
}
}
module.exports = HookCodeFactory;