Function decodeArrayBufferByCharset

Pagetual/pagetual.user.js:4193–4235

(buffer, preferredCharset)

            return match && match[1] ? match[1].trim() : "";
        }
        function decodeArrayBufferByCharset(buffer, preferredCharset) {
            let bytes = new Uint8Array(buffer);
            let decoderList = [];
            let normalize = label => String(label || "").trim().toLowerCase();
            let addAlias = (name, aliases) => {
                if (aliases.indexOf(normalizedPreferred) !== -1) {
                    pushDecoder(name);
                    for (let i = 0; i < aliases.length; i++) {
                        pushDecoder(aliases[i]);
                    }
                }
            };
            let pushDecoder = label => {
                let raw = String(label || "").trim();
                if (raw && decoderList.indexOf(raw) === -1) {
                    decoderList.push(raw);
                }
            };
            let normalizedPreferred = normalize(preferredCharset).replace(/["']/g, "");
            pushDecoder(preferredCharset);
            pushDecoder(normalizedPreferred);
            pushDecoder(normalizedPreferred.replace(/_/g, "-"));
            pushDecoder(normalizedPreferred.replace(/-/g, "_"));
            addAlias("shift_jis", ["shiftjis", "shift-jis", "sjis", "ms_kanji", "windows-31j", "cp932", "ms932"]);
            addAlias("euc-jp", ["eucjp"]);
            addAlias("iso-2022-jp", ["iso2022jp", "jis"]);
            addAlias("gb18030", ["gbk", "gb2312", "x-gbk", "cp936", "ms936", "windows-936"]);
            addAlias("big5", ["big-5", "cn-big5", "x-x-big5"]);
            addAlias("euc-kr", ["euckr", "ks_c_5601-1987", "ksc5601", "windows-949", "cp949"]);
            addAlias("windows-1251", ["cp1251"]);
            addAlias("windows-1252", ["cp1252", "iso-8859-1", "latin1", "latin-1"]);
            pushDecoder("utf-8");
            for (let i = 0; i < decoderList.length; i++) {
                try {
                    return new TextDecoder(decoderList[i]).decode(bytes);
                } catch (e) {}
            }
            try {
                return new TextDecoder().decode(bytes);
            } catch (e) {
                return "";
            }
        }
        function detectCharsetFromHtmlHead(buffer) {
            if (!buffer || !buffer.byteLength) return "";
            let scanLen = Math.min(buffer.byteLength, 16384);