--- /dev/null
+'use strict';
+
+var _Object$setPrototypeO;
+
+function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
+
+var finished = require('./end-of-stream');
+
+var kLastResolve = Symbol('lastResolve');
+var kLastReject = Symbol('lastReject');
+var kError = Symbol('error');
+var kEnded = Symbol('ended');
+var kLastPromise = Symbol('lastPromise');
+var kHandlePromise = Symbol('handlePromise');
+var kStream = Symbol('stream');
+
+function createIterResult(value, done) {
+ return {
+ value: value,
+ done: done
+ };
+}
+
+function readAndResolve(iter) {
+ var resolve = iter[kLastResolve];
+
+ if (resolve !== null) {
+ var data = iter[kStream].read(); // we defer if data is null
+ // we can be expecting either 'end' or
+ // 'error'
+
+ if (data !== null) {
+ iter[kLastPromise] = null;
+ iter[kLastResolve] = null;
+ iter[kLastReject] = null;
+ resolve(createIterResult(data, false));
+ }
+ }
+}
+
+function onReadable(iter) {
+ // we wait for the next tick, because it might
+ // emit an error with process.nextTick
+ process.nextTick(readAndResolve, iter);
+}
+
+function wrapForNext(lastPromise, iter) {
+ return function (resolve, reject) {
+ lastPromise.then(function () {
+ if (iter[kEnded]) {
+ resolve(createIterResult(undefined, true));
+ return;
+ }
+
+ iter[kHandlePromise](resolve, reject);
+ }, reject);
+ };
+}
+
+var AsyncIteratorPrototype = Object.getPrototypeOf(function () {});
+var ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf((_Object$setPrototypeO = {
+ get stream() {
+ return this[kStream];
+ },
+
+ next: function next() {
+ var _this = this;
+
+ // if we have detected an error in the meanwhile
+ // reject straight away
+ var error = this[kError];
+
+ if (error !== null) {
+ return Promise.reject(error);
+ }
+
+ if (this[kEnded]) {
+ return Promise.resolve(createIterResult(undefined, true));
+ }
+
+ if (this[kStream].destroyed) {
+ // We need to defer via nextTick because if .destroy(err) is
+ // called, the error will be emitted via nextTick, and
+ // we cannot guarantee that there is no error lingering around
+ // waiting to be emitted.
+ return new Promise(function (resolve, reject) {
+ process.nextTick(function () {
+ if (_this[kError]) {
+ reject(_this[kError]);
+ } else {
+ resolve(createIterResult(undefined, true));
+ }
+ });
+ });
+ } // if we have multiple next() calls
+ // we will wait for the previous Promise to finish
+ // this logic is optimized to support for await loops,
+ // where next() is only called once at a time
+
+
+ var lastPromise = this[kLastPromise];
+ var promise;
+
+ if (lastPromise) {
+ promise = new Promise(wrapForNext(lastPromise, this));
+ } else {
+ // fast path needed to support multiple this.push()
+ // without triggering the next() queue
+ var data = this[kStream].read();
+
+ if (data !== null) {
+ return Promise.resolve(createIterResult(data, false));
+ }
+
+ promise = new Promise(this[kHandlePromise]);
+ }
+
+ this[kLastPromise] = promise;
+ return promise;
+ }
+}, _defineProperty(_Object$setPrototypeO, Symbol.asyncIterator, function () {
+ return this;
+}), _defineProperty(_Object$setPrototypeO, "return", function _return() {
+ var _this2 = this;
+
+ // destroy(err, cb) is a private API
+ // we can guarantee we have that here, because we control the
+ // Readable class this is attached to
+ return new Promise(function (resolve, reject) {
+ _this2[kStream].destroy(null, function (err) {
+ if (err) {
+ reject(err);
+ return;
+ }
+
+ resolve(createIterResult(undefined, true));
+ });
+ });
+}), _Object$setPrototypeO), AsyncIteratorPrototype);
+
+var createReadableStreamAsyncIterator = function createReadableStreamAsyncIterator(stream) {
+ var _Object$create;
+
+ var iterator = Object.create(ReadableStreamAsyncIteratorPrototype, (_Object$create = {}, _defineProperty(_Object$create, kStream, {
+ value: stream,
+ writable: true
+ }), _defineProperty(_Object$create, kLastResolve, {
+ value: null,
+ writable: true
+ }), _defineProperty(_Object$create, kLastReject, {
+ value: null,
+ writable: true
+ }), _defineProperty(_Object$create, kError, {
+ value: null,
+ writable: true
+ }), _defineProperty(_Object$create, kEnded, {
+ value: stream._readableState.endEmitted,
+ writable: true
+ }), _defineProperty(_Object$create, kHandlePromise, {
+ value: function value(resolve, reject) {
+ var data = iterator[kStream].read();
+
+ if (data) {
+ iterator[kLastPromise] = null;
+ iterator[kLastResolve] = null;
+ iterator[kLastReject] = null;
+ resolve(createIterResult(data, false));
+ } else {
+ iterator[kLastResolve] = resolve;
+ iterator[kLastReject] = reject;
+ }
+ },
+ writable: true
+ }), _Object$create));
+ iterator[kLastPromise] = null;
+ finished(stream, function (err) {
+ if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
+ var reject = iterator[kLastReject]; // reject if we are waiting for data in the Promise
+ // returned by next() and store the error
+
+ if (reject !== null) {
+ iterator[kLastPromise] = null;
+ iterator[kLastResolve] = null;
+ iterator[kLastReject] = null;
+ reject(err);
+ }
+
+ iterator[kError] = err;
+ return;
+ }
+
+ var resolve = iterator[kLastResolve];
+
+ if (resolve !== null) {
+ iterator[kLastPromise] = null;
+ iterator[kLastResolve] = null;
+ iterator[kLastReject] = null;
+ resolve(createIterResult(undefined, true));
+ }
+
+ iterator[kEnded] = true;
+ });
+ stream.on('readable', onReadable.bind(null, iterator));
+ return iterator;
+};
+
+module.exports = createReadableStreamAsyncIterator;
\ No newline at end of file
projects / dotfiles / .git / blobdiff