@prisma/engine-core/dist/byline.js

"use strict";
// Copyright (C) 2011-2015 John Hewson
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
Object.defineProperty(exports, "__esModule", { value: true });
var stream = require('stream'), util = require('util');
// convinience API
function byline(readStream, options) {
    return module.exports.createStream(readStream, options);
}
exports.default = byline;
// basic API
module.exports.createStream = function (readStream, options) {
    if (readStream) {
        return createLineStream(readStream, options);
    }
    else {
        return new LineStream(options);
    }
};
function createLineStream(readStream, options) {
    if (!readStream) {
        throw new Error('expected readStream');
    }
    if (!readStream.readable) {
        throw new Error('readStream must be readable');
    }
    var ls = new LineStream(options);
    readStream.pipe(ls);
    return ls;
}
exports.createLineStream = createLineStream;
//
// using the new node v0.10 "streams2" API
//
module.exports.LineStream = LineStream;
function LineStream(options) {
    stream.Transform.call(this, options);
    options = options || {};
    // use objectMode to stop the output from being buffered
    // which re-concatanates the lines, just without newlines.
    this._readableState.objectMode = true;
    this._lineBuffer = [];
    this._keepEmptyLines = options.keepEmptyLines || false;
    this._lastChunkEndedWithCR = false;
    // take the source's encoding if we don't have one
    this.on('pipe', function (src) {
        if (!this.encoding) {
            // but we can't do this for old-style streams
            if (src instanceof stream.Readable) {
                this.encoding = src._readableState.encoding;
            }
        }
    });
}
util.inherits(LineStream, stream.Transform);
LineStream.prototype._transform = function (chunk, encoding, done) {
    // decode binary chunks as UTF-8
    encoding = encoding || 'utf8';
    if (Buffer.isBuffer(chunk)) {
        if (encoding == 'buffer') {
            chunk = chunk.toString(); // utf8
            encoding = 'utf8';
        }
        else {
            chunk = chunk.toString(encoding);
        }
    }
    this._chunkEncoding = encoding;
    var lines = chunk.split(/\r\n|\r|\n/g);
    // don't split CRLF which spans chunks
    if (this._lastChunkEndedWithCR && chunk[0] == '\n') {
        lines.shift();
    }
    if (this._lineBuffer.length > 0) {
        this._lineBuffer[this._lineBuffer.length - 1] += lines[0];
        lines.shift();
    }
    this._lastChunkEndedWithCR = chunk[chunk.length - 1] == '\r';
    this._lineBuffer = this._lineBuffer.concat(lines);
    this._pushBuffer(encoding, 1, done);
};
LineStream.prototype._pushBuffer = function (encoding, keep, done) {
    // always buffer the last (possibly partial) line
    while (this._lineBuffer.length > keep) {
        var line = this._lineBuffer.shift();
        // skip empty lines
        if (this._keepEmptyLines || line.length > 0) {
            if (!this.push(this._reencode(line, encoding))) {
                // when the high-water mark is reached, defer pushes until the next tick
                var self = this;
                setImmediate(function () {
                    self._pushBuffer(encoding, keep, done);
                });
                return;
            }
        }
    }
    done();
};
LineStream.prototype._flush = function (done) {
    this._pushBuffer(this._chunkEncoding, 0, done);
};
// see Readable::push
LineStream.prototype._reencode = function (line, chunkEncoding) {
    if (this.encoding && this.encoding != chunkEncoding) {
        return Buffer.from(line, chunkEncoding).toString(this.encoding);
    }
    else if (this.encoding) {
        // this should be the most common case, i.e. we're using an encoded source stream
        return line;
    }
    else {
        return Buffer.from(line, chunkEncoding);
    }
};
//# sourceMappingURL=byline.js.map