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JavaScript

'use strict';
var crypto = require('crypto');
/**
* Exported function
*
* Options:
*
* - `algorithm` hash algo to be used by this instance: *'sha1', 'md5'
* - `excludeValues` {true|*false} hash object keys, values ignored
* - `encoding` hash encoding, supports 'buffer', '*hex', 'binary', 'base64'
* - `ignoreUnknown` {true|*false} ignore unknown object types
* - `replacer` optional function that replaces values before hashing
* - `respectFunctionProperties` {*true|false} consider function properties when hashing
* - `respectFunctionNames` {*true|false} consider 'name' property of functions for hashing
* - `respectType` {*true|false} Respect special properties (prototype, constructor)
* when hashing to distinguish between types
* - `unorderedArrays` {true|*false} Sort all arrays before hashing
* - `unorderedSets` {*true|false} Sort `Set` and `Map` instances before hashing
* * = default
*
* @param {object} object value to hash
* @param {object} options hashing options
* @return {string} hash value
* @api public
*/
exports = module.exports = objectHash;
function objectHash(object, options){
options = applyDefaults(object, options);
return hash(object, options);
}
/**
* Exported sugar methods
*
* @param {object} object value to hash
* @return {string} hash value
* @api public
*/
exports.sha1 = function(object){
return objectHash(object);
};
exports.keys = function(object){
return objectHash(object, {excludeValues: true, algorithm: 'sha1', encoding: 'hex'});
};
exports.MD5 = function(object){
return objectHash(object, {algorithm: 'md5', encoding: 'hex'});
};
exports.keysMD5 = function(object){
return objectHash(object, {algorithm: 'md5', encoding: 'hex', excludeValues: true});
};
// Internals
var hashes = crypto.getHashes ? crypto.getHashes().slice() : ['sha1', 'md5'];
hashes.push('passthrough');
var encodings = ['buffer', 'hex', 'binary', 'base64'];
function applyDefaults(object, sourceOptions){
sourceOptions = sourceOptions || {};
// create a copy rather than mutating
var options = {};
options.algorithm = sourceOptions.algorithm || 'sha1';
options.encoding = sourceOptions.encoding || 'hex';
options.excludeValues = sourceOptions.excludeValues ? true : false;
options.algorithm = options.algorithm.toLowerCase();
options.encoding = options.encoding.toLowerCase();
options.ignoreUnknown = sourceOptions.ignoreUnknown !== true ? false : true; // default to false
options.respectType = sourceOptions.respectType === false ? false : true; // default to true
options.respectFunctionNames = sourceOptions.respectFunctionNames === false ? false : true;
options.respectFunctionProperties = sourceOptions.respectFunctionProperties === false ? false : true;
options.unorderedArrays = sourceOptions.unorderedArrays !== true ? false : true; // default to false
options.unorderedSets = sourceOptions.unorderedSets === false ? false : true; // default to false
options.unorderedObjects = sourceOptions.unorderedObjects === false ? false : true; // default to true
options.replacer = sourceOptions.replacer || undefined;
options.excludeKeys = sourceOptions.excludeKeys || undefined;
if(typeof object === 'undefined') {
throw new Error('Object argument required.');
}
// if there is a case-insensitive match in the hashes list, accept it
// (i.e. SHA256 for sha256)
for (var i = 0; i < hashes.length; ++i) {
if (hashes[i].toLowerCase() === options.algorithm.toLowerCase()) {
options.algorithm = hashes[i];
}
}
if(hashes.indexOf(options.algorithm) === -1){
throw new Error('Algorithm "' + options.algorithm + '" not supported. ' +
'supported values: ' + hashes.join(', '));
}
if(encodings.indexOf(options.encoding) === -1 &&
options.algorithm !== 'passthrough'){
throw new Error('Encoding "' + options.encoding + '" not supported. ' +
'supported values: ' + encodings.join(', '));
}
return options;
}
/** Check if the given function is a native function */
function isNativeFunction(f) {
if ((typeof f) !== 'function') {
return false;
}
var exp = /^function\s+\w*\s*\(\s*\)\s*{\s+\[native code\]\s+}$/i;
return exp.exec(Function.prototype.toString.call(f)) != null;
}
function hash(object, options) {
var hashingStream;
if (options.algorithm !== 'passthrough') {
hashingStream = crypto.createHash(options.algorithm);
} else {
hashingStream = new PassThrough();
}
if (typeof hashingStream.write === 'undefined') {
hashingStream.write = hashingStream.update;
hashingStream.end = hashingStream.update;
}
var hasher = typeHasher(options, hashingStream);
hasher.dispatch(object);
if (!hashingStream.update) {
hashingStream.end('');
}
if (hashingStream.digest) {
return hashingStream.digest(options.encoding === 'buffer' ? undefined : options.encoding);
}
var buf = hashingStream.read();
if (options.encoding === 'buffer') {
return buf;
}
return buf.toString(options.encoding);
}
/**
* Expose streaming API
*
* @param {object} object Value to serialize
* @param {object} options Options, as for hash()
* @param {object} stream A stream to write the serializiation to
* @api public
*/
exports.writeToStream = function(object, options, stream) {
if (typeof stream === 'undefined') {
stream = options;
options = {};
}
options = applyDefaults(object, options);
return typeHasher(options, stream).dispatch(object);
};
function typeHasher(options, writeTo, context){
context = context || [];
var write = function(str) {
if (writeTo.update) {
return writeTo.update(str, 'utf8');
} else {
return writeTo.write(str, 'utf8');
}
};
return {
dispatch: function(value){
if (options.replacer) {
value = options.replacer(value);
}
var type = typeof value;
if (value === null) {
type = 'null';
}
//console.log("[DEBUG] Dispatch: ", value, "->", type, " -> ", "_" + type);
return this['_' + type](value);
},
_object: function(object) {
var pattern = (/\[object (.*)\]/i);
var objString = Object.prototype.toString.call(object);
var objType = pattern.exec(objString);
if (!objType) { // object type did not match [object ...]
objType = 'unknown:[' + objString + ']';
} else {
objType = objType[1]; // take only the class name
}
objType = objType.toLowerCase();
var objectNumber = null;
if ((objectNumber = context.indexOf(object)) >= 0) {
return this.dispatch('[CIRCULAR:' + objectNumber + ']');
} else {
context.push(object);
}
if (typeof Buffer !== 'undefined' && Buffer.isBuffer && Buffer.isBuffer(object)) {
write('buffer:');
return write(object);
}
if(objType !== 'object' && objType !== 'function' && objType !== 'asyncfunction') {
if(this['_' + objType]) {
this['_' + objType](object);
} else if (options.ignoreUnknown) {
return write('[' + objType + ']');
} else {
throw new Error('Unknown object type "' + objType + '"');
}
}else{
var keys = Object.keys(object);
if (options.unorderedObjects) {
keys = keys.sort();
}
// Make sure to incorporate special properties, so
// Types with different prototypes will produce
// a different hash and objects derived from
// different functions (`new Foo`, `new Bar`) will
// produce different hashes.
// We never do this for native functions since some
// seem to break because of that.
if (options.respectType !== false && !isNativeFunction(object)) {
keys.splice(0, 0, 'prototype', '__proto__', 'constructor');
}
if (options.excludeKeys) {
keys = keys.filter(function(key) { return !options.excludeKeys(key); });
}
write('object:' + keys.length + ':');
var self = this;
return keys.forEach(function(key){
self.dispatch(key);
write(':');
if(!options.excludeValues) {
self.dispatch(object[key]);
}
write(',');
});
}
},
_array: function(arr, unordered){
unordered = typeof unordered !== 'undefined' ? unordered :
options.unorderedArrays !== false; // default to options.unorderedArrays
var self = this;
write('array:' + arr.length + ':');
if (!unordered || arr.length <= 1) {
return arr.forEach(function(entry) {
return self.dispatch(entry);
});
}
// the unordered case is a little more complicated:
// since there is no canonical ordering on objects,
// i.e. {a:1} < {a:2} and {a:1} > {a:2} are both false,
// we first serialize each entry using a PassThrough stream
// before sorting.
// also: we cant use the same context array for all entries
// since the order of hashing should *not* matter. instead,
// we keep track of the additions to a copy of the context array
// and add all of them to the global context array when were done
var contextAdditions = [];
var entries = arr.map(function(entry) {
var strm = new PassThrough();
var localContext = context.slice(); // make copy
var hasher = typeHasher(options, strm, localContext);
hasher.dispatch(entry);
// take only what was added to localContext and append it to contextAdditions
contextAdditions = contextAdditions.concat(localContext.slice(context.length));
return strm.read().toString();
});
context = context.concat(contextAdditions);
entries.sort();
return this._array(entries, false);
},
_date: function(date){
return write('date:' + date.toJSON());
},
_symbol: function(sym){
return write('symbol:' + sym.toString());
},
_error: function(err){
return write('error:' + err.toString());
},
_boolean: function(bool){
return write('bool:' + bool.toString());
},
_string: function(string){
write('string:' + string.length + ':');
write(string.toString());
},
_function: function(fn){
write('fn:');
if (isNativeFunction(fn)) {
this.dispatch('[native]');
} else {
this.dispatch(fn.toString());
}
if (options.respectFunctionNames !== false) {
// Make sure we can still distinguish native functions
// by their name, otherwise String and Function will
// have the same hash
this.dispatch("function-name:" + String(fn.name));
}
if (options.respectFunctionProperties) {
this._object(fn);
}
},
_number: function(number){
return write('number:' + number.toString());
},
_xml: function(xml){
return write('xml:' + xml.toString());
},
_null: function() {
return write('Null');
},
_undefined: function() {
return write('Undefined');
},
_regexp: function(regex){
return write('regex:' + regex.toString());
},
_uint8array: function(arr){
write('uint8array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_uint8clampedarray: function(arr){
write('uint8clampedarray:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_int8array: function(arr){
write('int8array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_uint16array: function(arr){
write('uint16array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_int16array: function(arr){
write('int16array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_uint32array: function(arr){
write('uint32array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_int32array: function(arr){
write('int32array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_float32array: function(arr){
write('float32array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_float64array: function(arr){
write('float64array:');
return this.dispatch(Array.prototype.slice.call(arr));
},
_arraybuffer: function(arr){
write('arraybuffer:');
return this.dispatch(new Uint8Array(arr));
},
_url: function(url) {
return write('url:' + url.toString(), 'utf8');
},
_map: function(map) {
write('map:');
var arr = Array.from(map);
return this._array(arr, options.unorderedSets !== false);
},
_set: function(set) {
write('set:');
var arr = Array.from(set);
return this._array(arr, options.unorderedSets !== false);
},
_file: function(file) {
write('file:');
return this.dispatch([file.name, file.size, file.type, file.lastModfied]);
},
_blob: function() {
if (options.ignoreUnknown) {
return write('[blob]');
}
throw Error('Hashing Blob objects is currently not supported\n' +
'(see https://github.com/puleos/object-hash/issues/26)\n' +
'Use "options.replacer" or "options.ignoreUnknown"\n');
},
_domwindow: function() { return write('domwindow'); },
_bigint: function(number){
return write('bigint:' + number.toString());
},
/* Node.js standard native objects */
_process: function() { return write('process'); },
_timer: function() { return write('timer'); },
_pipe: function() { return write('pipe'); },
_tcp: function() { return write('tcp'); },
_udp: function() { return write('udp'); },
_tty: function() { return write('tty'); },
_statwatcher: function() { return write('statwatcher'); },
_securecontext: function() { return write('securecontext'); },
_connection: function() { return write('connection'); },
_zlib: function() { return write('zlib'); },
_context: function() { return write('context'); },
_nodescript: function() { return write('nodescript'); },
_httpparser: function() { return write('httpparser'); },
_dataview: function() { return write('dataview'); },
_signal: function() { return write('signal'); },
_fsevent: function() { return write('fsevent'); },
_tlswrap: function() { return write('tlswrap'); },
};
}
// Mini-implementation of stream.PassThrough
// We are far from having need for the full implementation, and we can
// make assumptions like "many writes, then only one final read"
// and we can ignore encoding specifics
function PassThrough() {
return {
buf: '',
write: function(b) {
this.buf += b;
},
end: function(b) {
this.buf += b;
},
read: function() {
return this.buf;
}
};
}