read-gedcom
Version:
Gedcom file reader
128 lines • 5.51 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.parseGedcom = void 0;
const decoder_1 = require("./decoder");
const decoding_1 = require("./decoding");
const error_1 = require("./error");
const indexer_1 = require("./indexer");
const structurer_1 = require("./structurer");
const tokenizer_1 = require("./tokenizer");
/**
* Reads a Gedcom file and returns it as a tree representation.
* @param buffer The content of the file
* @param options Optional parameters
* @throws ErrorParse If the file cannot be interpreted correctly
* @category Gedcom parser
*/
const parseGedcom = (buffer, options = {}) => {
checkMagicHeader(buffer);
const charset = options.forcedCharset == null ? (0, decoder_1.detectCharset)(buffer) : options.forcedCharset;
const callback = options.progressCallback;
const totalBytes = buffer.byteLength;
const decodingCallback = callback ? (bytesRead) => callback(0 /* GedcomReadingPhase.Decoding */, bytesRead / totalBytes) : undefined;
let input;
if (charset === "UTF-8" /* FileEncoding.Utf8 */ || charset === "UTF-16be" /* FileEncoding.Utf16be */ || charset === "UTF-16le" /* FileEncoding.Utf16le */) {
input = (0, decoding_1.decodeUtf)(buffer, decodingCallback);
}
else if (charset === "Cp1252" /* FileEncoding.Cp1252 */) {
input = (0, decoding_1.decodeCp1252)(buffer, decodingCallback);
}
else if (charset === "ANSEL" /* FileEncoding.Ansel */) {
input = (0, decoding_1.decodeAnsel)(buffer, decodingCallback, !!options.doStrictDecoding);
}
else if (charset === "Macintosh" /* FileEncoding.Macintosh */) {
input = (0, decoding_1.decodeMacintosh)(buffer, decodingCallback);
}
else if (charset === "Cp850" /* FileEncoding.Cp850 */) {
input = (0, decoding_1.decodeCp850)(buffer, decodingCallback);
}
else {
throw new error_1.ErrorUnsupportedCharset(`Unsupported charset: ${charset}`, charset);
}
const totalChars = input.length;
const tokensIterator = (0, tokenizer_1.tokenize)(input);
const rootNode = (0, structurer_1.buildTree)(tokensIterator, !!options.noInlineContinuations, callback ? charsRead => callback(1 /* GedcomReadingPhase.TokenizationAndStructuring */, charsRead / totalChars) : null);
checkTreeStructure(rootNode);
if (!options.noIndex) {
(0, indexer_1.indexTree)(rootNode, !!options.noBackwardsReferencesIndex, !!options.doHideIndex, callback ? () => callback(2 /* GedcomReadingPhase.Indexing */, null) : null);
}
if (options.doFreeze) {
if (callback) {
callback(3 /* GedcomReadingPhase.Freezing */, 0);
}
deepFreeze(rootNode);
if (callback) {
callback(3 /* GedcomReadingPhase.Freezing */, 1);
}
}
return rootNode;
};
exports.parseGedcom = parseGedcom;
/**
* A simple and fast testing procedure to eliminate files that are clearly not Gedcoms.
* @param buffer The content of the file
*/
const checkMagicHeader = (buffer) => {
const headStr = '0 HEAD';
const head = [];
for (let i = 0; i < headStr.length; i++) {
head.push(headStr.charCodeAt(i));
}
const byteBuffer = new Uint8Array(buffer);
const startsWith = (bytes) => {
if (byteBuffer.byteLength < bytes.length) {
return false;
}
for (let i = 0; i < bytes.length; i++) {
if (bytes[i] !== byteBuffer[i]) {
return false;
}
}
return true;
};
if (!startsWith(head) && !startsWith(decoding_1.BOM_UTF8.concat(head))) { // Not ASCII nor any of its extensions, including UTF-8
const headUtf16 = head.map(b => [0, b]);
if (!startsWith(decoding_1.BOM_UTF16_BE.concat(headUtf16.flat())) &&
!startsWith(decoding_1.BOM_UTF16_LE.concat(headUtf16.map(bs => bs.slice().reverse()).flat()))) { // Not UTF-16
const headUtf32 = head.map(b => [0, 0, 0, b]);
if (!startsWith(decoding_1.BOM_UTF32_BE.concat(headUtf32.flat())) &&
!startsWith(decoding_1.BOM_UTF32_LE.concat(headUtf32.map(bs => bs.slice().reverse()).flat()))) { // Not UTF-32
throw new error_1.ErrorInvalidFileType('Probably not a Gedcom file');
}
}
}
};
/**
* A simple procedure verifying that the root node starts with a {@link Tag.Header} and ends with a {@link Tag.Trailer}.
* @param rootNode The root node
*/
const checkTreeStructure = (rootNode) => {
const root = rootNode.children;
// Assumes that `root.length > 0`
const header = root[0];
if (header.tag !== "HEAD" /* Tag.Header */) {
throw new error_1.ErrorTreeStructure(`First node is not a header (got ${header.tag})`);
}
const trailer = root[root.length - 1];
if (trailer.tag !== "TRLR" /* Tag.Trailer */) {
throw new error_1.ErrorTreeStructure(`Last node is not a trailer (got ${trailer.tag})`);
}
};
/**
* Freezes this object to prevent further modifications.
* @param object The object to be frozen
*/
const deepFreeze = (object) => {
let queue = [object];
while (queue.length > 0) {
const next = [];
queue.forEach(obj => {
if (obj != null && typeof obj === 'object' && !Object.isFrozen(obj)) {
Object.freeze(obj);
Object.getOwnPropertyNames(obj).forEach(property => next.push(obj[property]));
}
});
queue = next;
}
};
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