46 lines
1.1 KiB
JavaScript
46 lines
1.1 KiB
JavaScript
"use strict";
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let SyncReader = (module.exports = function (buffer) {
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this._buffer = buffer;
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this._reads = [];
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});
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SyncReader.prototype.read = function (length, callback) {
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this._reads.push({
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length: Math.abs(length), // if length < 0 then at most this length
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allowLess: length < 0,
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func: callback,
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});
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};
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SyncReader.prototype.process = function () {
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// as long as there is any data and read requests
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while (this._reads.length > 0 && this._buffer.length) {
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let read = this._reads[0];
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if (
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this._buffer.length &&
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(this._buffer.length >= read.length || read.allowLess)
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) {
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// ok there is any data so that we can satisfy this request
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this._reads.shift(); // == read
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let buf = this._buffer;
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this._buffer = buf.slice(read.length);
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read.func.call(this, buf.slice(0, read.length));
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} else {
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break;
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}
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}
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if (this._reads.length > 0) {
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return new Error("There are some read requests waitng on finished stream");
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}
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if (this._buffer.length > 0) {
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return new Error("unrecognised content at end of stream");
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}
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};
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