@syncfusion/ej2-pdf/src/pdf/core/compression/ascii-85-stream.js

Feature-rich JavaScript PDF library with built-in support for loading and manipulating PDF document.

var __extends = (this && this.__extends) || (function () {
    var extendStatics = function (d, b) {
        extendStatics = Object.setPrototypeOf ||
            ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
            function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
        return extendStatics(d, b);
    };
    return function (d, b) {
        extendStatics(d, b);
        function __() { this.constructor = d; }
        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
    };
})();
import { _PdfDecodeStream } from '../decode-stream';
import { _isWhiteSpace } from '../utils';
/**
 * Decodes ASCII85 encoded data from an underlying byte stream into binary content.
 *
 * @private
 */
var _PdfAscii85Stream = /** @class */ (function (_super) {
    __extends(_PdfAscii85Stream, _super);
    function _PdfAscii85Stream(str, maybeLength) {
        var _this = this;
        if (maybeLength) {
            maybeLength *= 0.8;
        }
        _this = _super.call(this, maybeLength) || this;
        _this.stream = str;
        _this.input = new Uint8Array(5);
        return _this;
    }
    _PdfAscii85Stream.prototype.readBlock = function () {
        var tildaCharacter = 0x7e;
        var lowerCharacter = 0x7a;
        var eof = -1;
        var str = this.stream; // eslint-disable-line
        var c = str.getByte(); // eslint-disable-line
        while (_isWhiteSpace(c)) {
            c = str.getByte();
        }
        if (c === eof || c === tildaCharacter) {
            this.eof = true;
            return;
        }
        var bufferLength = this.bufferLength;
        var buffer; // eslint-disable-line
        var i;
        if (c === lowerCharacter) {
            buffer = this.ensureBuffer(bufferLength + 4);
            for (i = 0; i < 4; ++i) {
                buffer[bufferLength + i] = 0;
            }
            this.bufferLength += 4;
        }
        else {
            var input = this.input; // eslint-disable-line
            input[0] = c;
            for (i = 1; i < 5; ++i) {
                c = str.getByte();
                while (_isWhiteSpace(c)) {
                    c = str.getByte();
                }
                input[Number.parseInt(i.toString(), 10)] = c;
                if (c === eof || c === tildaCharacter) {
                    break;
                }
            }
            buffer = this.ensureBuffer(bufferLength + i - 1);
            this.bufferLength += i - 1;
            if (i < 5) {
                for (; i < 5; ++i) {
                    input[Number.parseInt(i.toString(), 10)] = 0x21 + 84;
                }
                this.eof = true;
            }
            var t = 0;
            for (i = 0; i < 5; ++i) {
                t = t * 85 + (input[Number.parseInt(i.toString(), 10)] - 0x21);
            }
            for (i = 3; i >= 0; --i) {
                buffer[bufferLength + i] = t & 0xff;
                t >>= 8;
            }
        }
    };
    return _PdfAscii85Stream;
}(_PdfDecodeStream));
export { _PdfAscii85Stream };