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schemas.js
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schemas.js
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/* jshint node: true */
// TODO: Add schema inference capabilities (as writable stream?).
// TODO: Use toFastProperties on type reverse indices.
// TODO: Allow configuring when to write the size when writing arrays and maps,
// and customizing their block size.
// TODO: Code-generate `compare` and `clone` record and union methods.
'use strict';
var utils = require('./utils'),
buffer = require('buffer'), // For `SlowBuffer`.
crypto = require('crypto'),
util = require('util');
// Convenience imports.
var Tap = utils.Tap;
var f = util.format;
// All Avro types.
var TYPES = {
'array': ArrayType,
'boolean': BooleanType,
'bytes': BytesType,
'double': DoubleType,
'enum': EnumType,
'error': RecordType,
'fixed': FixedType,
'float': FloatType,
'int': IntType,
'long': LongType,
'map': MapType,
'null': NullType,
'record': RecordType,
'string': StringType,
'union': UnionType
};
// Valid (field, type, and symbol) name regex.
var NAME_PATTERN = /^[A-Za-z_][A-Za-z0-9_]*$/;
// Random generator.
var RANDOM = new utils.Lcg();
// Encoding tap (shared for performance).
var TAP = new Tap(new buffer.SlowBuffer(1024));
// Path prefix for validity checks (shared for performance).
var PATH = [];
// Currently active logical type, used for name redirection.
var LOGICAL_TYPE = null;
/**
* Schema parsing entry point.
*
* It isn't exposed directly but called from `parse` inside `index.js` (node)
* or `avsc.js` (browserify) which each add convenience functionality.
*
*/
function createType(attrs, opts) {
if (attrs instanceof Type) {
return attrs;
}
opts = getOpts(attrs, opts);
var type;
if (typeof attrs == 'string') { // Type reference.
if (opts.namespace && !~attrs.indexOf('.') && !isPrimitive(attrs)) {
attrs = opts.namespace + '.' + attrs;
}
type = opts.registry[attrs];
if (type) {
// Type was already defined, return it.
return type;
}
if (isPrimitive(attrs)) {
// Reference to a primitive type. These are also defined names by default
// so we create the appropriate type and it to the registry for future
// reference.
return opts.registry[attrs] = createType({type: attrs}, opts);
}
throw new Error(f('undefined type name: %s', attrs));
}
if (opts.typeHook && (type = opts.typeHook(attrs, opts))) {
if (!(type instanceof Type)) {
throw new Error(f('invalid typehook return value: %j', type));
}
return type;
}
if (attrs.logicalType && !LOGICAL_TYPE) {
var DerivedType = opts.logicalTypes[attrs.logicalType];
if (DerivedType) {
var registry = {};
Object.keys(opts.registry).map(function (key) {
registry[key] = opts.registry[key];
});
try {
return new DerivedType(attrs, opts);
} catch (err) {
if (opts.assertLogicalType) {
// The spec mandates that we fall through to the underlying type if
// the logical type is invalid. We provide this option to ease
// debugging.
throw err;
}
LOGICAL_TYPE = null;
opts.registry = registry; // In case any names were registered.
}
}
}
if (attrs instanceof Array) { // Union.
type = new UnionType(attrs, opts);
} else { // New type definition.
type = (function (typeName) {
var Type = TYPES[attrs.type];
if (Type === undefined) {
throw new Error(f('unknown type: %j', typeName));
}
return new Type(attrs, opts);
})(attrs.type);
}
return type;
}
/**
* "Abstract" base Avro type class.
*
* This class' constructor will register any named types to support
* recursive schemas.
*
* All type values are represented in memory similarly to their JSON
* representation, except for `bytes` and `fixed` which are represented as
* `Buffer`s. See individual subclasses for details.
*
*/
function Type(registry) {
var name = this._name;
var type = LOGICAL_TYPE || this;
LOGICAL_TYPE = null;
if (registry === undefined || name === undefined) {
return;
}
var prev = registry[name];
if (prev !== undefined) {
throw new Error(f('duplicate type name: %s', name));
}
registry[name] = type;
}
Type.__reset = function (size) { TAP.buf = new buffer.SlowBuffer(size); };
Type.prototype.createResolver = function (type, opts) {
if (!(type instanceof Type)) {
// More explicit error message than the "incompatible type" thrown
// otherwise (especially because of the overridden `toJSON` method).
throw new Error(f('not a type: %j', type));
}
if (type instanceof LogicalType && !(this instanceof LogicalType)) {
// Trying to read a logical type as a built-in: unwrap the logical type.
return this.createResolver(type._underlyingType, opts);
}
opts = opts || {};
opts.registry = opts.registry || {};
var resolver, key;
if (this instanceof RecordType && type instanceof RecordType) {
key = this._name + ':' + type._name; // ':' is illegal in Avro type names.
resolver = opts.registry[key];
if (resolver) {
return resolver;
}
}
resolver = new Resolver(this);
if (key) { // Register resolver early for recursive schemas.
opts.registry[key] = resolver;
}
if (type instanceof UnionType) {
var resolvers = type._types.map(function (t) {
return this.createResolver(t, opts);
}, this);
resolver._read = function (tap) {
var index = tap.readLong();
var resolver = resolvers[index];
if (resolver === undefined) {
throw new Error(f('invalid union index: %s', index));
}
return resolvers[index]._read(tap);
};
} else {
this._updateResolver(resolver, type, opts);
}
if (!resolver._read) {
throw new Error(f('cannot read %s as %s', type, this));
}
return resolver;
};
Type.prototype.decode = function (buf, pos, resolver) {
var tap = new Tap(buf);
tap.pos = pos | 0;
var val = readValue(this, tap, resolver);
if (!tap.isValid()) {
return {value: undefined, offset: -1};
}
return {value: val, offset: tap.pos};
};
Type.prototype.encode = function (val, buf, pos) {
var tap = new Tap(buf);
tap.pos = pos | 0;
this._write(tap, val);
if (!tap.isValid()) {
// Don't throw as there is no way to predict this. We also return the
// number of missing bytes to ease resizing.
return buf.length - tap.pos;
}
return tap.pos;
};
Type.prototype.fromBuffer = function (buf, resolver, noCheck) {
var tap = new Tap(buf);
var val = readValue(this, tap, resolver, noCheck);
if (!tap.isValid()) {
throw new Error('truncated buffer');
}
if (!noCheck && tap.pos < buf.length) {
throw new Error('trailing data');
}
return val;
};
Type.prototype.toBuffer = function (val) {
TAP.pos = 0;
this._write(TAP, val);
if (!TAP.isValid()) {
Type.__reset(2 * TAP.pos);
TAP.pos = 0;
this._write(TAP, val);
}
var buf = new Buffer(TAP.pos);
TAP.buf.copy(buf, 0, 0, TAP.pos);
return buf;
};
Type.prototype.fromString = function (str) {
return this._copy(JSON.parse(str), {coerce: 2});
};
Type.prototype.toString = function (val) {
if (val === undefined) {
// Consistent behavior with standard `toString` expectations.
return this.getSchema(true);
}
return JSON.stringify(this._copy(val, {coerce: 3}));
};
Type.prototype.clone = function (val, opts) {
if (opts) {
opts = {
coerce: !!opts.coerceBuffers | 0, // Coerce JSON to Buffer.
fieldHook: opts.fieldHook,
wrap: !!opts.wrapUnions | 0 // Wrap first match into union.
};
}
return this._copy(val, opts);
};
Type.prototype.isValid = function (val, opts) {
while (PATH.length) {
// In case the previous `isValid` call didn't complete successfully (e.g.
// if an exception was thrown, but then caught in client code), `PATH`
// might be non-empty, we must manually clear it.
PATH.pop();
}
return this._check(val, opts && opts.errorHook);
};
Type.prototype.compareBuffers = function (buf1, buf2) {
return this._match(new Tap(buf1), new Tap(buf2));
};
Type.prototype.getName = function () { return this._name; };
Type.prototype.getSchema = function (noDeref) {
// Since JS objects are unordered, this implementation (unfortunately)
// relies on engines returning properties in the same order that they are
// inserted in. This is not in the JS spec, but can be "somewhat" safely
// assumed (more here: http://stackoverflow.com/q/5525795/1062617).
return (function (type, registry) {
return JSON.stringify(type, function (key, value) {
if (value instanceof Field) {
return {name: value._name, type: value._type};
} else if (value && value.name) {
var name = value.name;
if (noDeref || registry[name]) {
return name;
}
registry[name] = true;
}
return value;
});
})(this, {});
};
Type.prototype.getFingerprint = function (algorithm) {
algorithm = algorithm || 'md5';
var hash = crypto.createHash(algorithm);
hash.end(this.getSchema());
return hash.read();
};
Type.prototype.inspect = function () {
if (this instanceof PrimitiveType) {
return f('<%s>', this.constructor.name);
} else {
var obj = JSON.parse(this.getSchema(true)); // Slow, only for debugging.
if (typeof obj == 'object') {
obj.type = undefined; // Would be redundant with constructor name.
}
return f('<%s %j>', this.constructor.name, obj);
}
};
Type.prototype._check = utils.abstractFunction;
Type.prototype._copy = utils.abstractFunction;
Type.prototype._match = utils.abstractFunction;
Type.prototype._read = utils.abstractFunction;
Type.prototype._skip = utils.abstractFunction;
Type.prototype._updateResolver = utils.abstractFunction;
Type.prototype._write = utils.abstractFunction;
Type.prototype.compare = utils.abstractFunction;
Type.prototype.random = utils.abstractFunction;
// Implementations.
/**
* Base primitive Avro type.
*
* Most of the primitive types share the same cloning and resolution
* mechanisms, provided by this class. This class also lets us conveniently
* check whether a type is a primitive using `instanceof`.
*
*/
function PrimitiveType() { Type.call(this); }
util.inherits(PrimitiveType, Type);
PrimitiveType.prototype._updateResolver = function (resolver, type) {
if (type.constructor === this.constructor) {
resolver._read = this._read;
}
};
PrimitiveType.prototype._copy = function (val) {
this._check(val, throwInvalidError);
return val;
};
PrimitiveType.prototype.compare = utils.compare;
/**
* Nulls.
*
*/
function NullType() { PrimitiveType.call(this); }
util.inherits(NullType, PrimitiveType);
NullType.prototype._check = function (val, cb) {
var b = val === null;
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
NullType.prototype._read = function () { return null; };
NullType.prototype._skip = function () {};
NullType.prototype._write = function (tap, val) {
if (val !== null) {
throwInvalidError(null, val, this);
}
};
NullType.prototype._match = function () { return 0; };
NullType.prototype.compare = NullType.prototype._match;
NullType.prototype.random = NullType.prototype._read;
NullType.prototype.toJSON = function () { return 'null'; };
/**
* Booleans.
*
*/
function BooleanType() { PrimitiveType.call(this); }
util.inherits(BooleanType, PrimitiveType);
BooleanType.prototype._check = function (val, cb) {
var b = typeof val == 'boolean';
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
BooleanType.prototype._read = function (tap) { return tap.readBoolean(); };
BooleanType.prototype._skip = function (tap) { tap.skipBoolean(); };
BooleanType.prototype._write = function (tap, val) {
if (typeof val != 'boolean') {
throwInvalidError(null, val, this);
}
tap.writeBoolean(val);
};
BooleanType.prototype._match = function (tap1, tap2) {
return tap1.matchBoolean(tap2);
};
BooleanType.prototype.random = function () { return RANDOM.nextBoolean(); };
BooleanType.prototype.toJSON = function () { return 'boolean'; };
/**
* Integers.
*
*/
function IntType() { PrimitiveType.call(this); }
util.inherits(IntType, PrimitiveType);
IntType.prototype._check = function (val, cb) {
var b = val === (val | 0);
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
IntType.prototype._read = function (tap) { return tap.readInt(); };
IntType.prototype._skip = function (tap) { tap.skipInt(); };
IntType.prototype._write = function (tap, val) {
if (val !== (val | 0)) {
throwInvalidError(null, val, this);
}
tap.writeInt(val);
};
IntType.prototype._match = function (tap1, tap2) {
return tap1.matchInt(tap2);
};
IntType.prototype.random = function () { return RANDOM.nextInt(1000) | 0; };
IntType.prototype.toJSON = function () { return 'int'; };
/**
* Longs.
*
* We can't capture all the range unfortunately since JavaScript represents all
* numbers internally as `double`s, so the default implementation plays safe
* and throws rather than potentially silently change the data. See `using` or
* `AbstractLongType` below for a way to implement a custom long type.
*
*/
function LongType() { PrimitiveType.call(this); }
util.inherits(LongType, PrimitiveType);
LongType.prototype._check = function (val, cb) {
var b = typeof val == 'number' && val % 1 === 0 && isSafeLong(val);
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
LongType.prototype._read = function (tap) {
var n = tap.readLong();
if (!isSafeLong(n)) {
throw new Error('potential precision loss');
}
return n;
};
LongType.prototype._skip = function (tap) { tap.skipLong(); };
LongType.prototype._write = function (tap, val) {
if (typeof val != 'number' || val % 1 || !isSafeLong(val)) {
throwInvalidError(null, val, this);
}
tap.writeLong(val);
};
LongType.prototype._match = function (tap1, tap2) {
return tap1.matchLong(tap2);
};
LongType.prototype._updateResolver = function (resolver, type) {
if (type instanceof LongType || type instanceof IntType) {
resolver._read = type._read;
}
};
LongType.prototype.random = function () { return RANDOM.nextInt(); };
LongType.prototype.toJSON = function () { return 'long'; };
LongType.using = function (methods, noUnpack) {
methods = methods || {}; // Will give a more helpful error message.
// We map some of the methods to a different name to be able to intercept
// their input and output (otherwise we wouldn't be able to perform any
// unpacking logic, and the type wouldn't work when nested).
var mapping = {
toBuffer: '_toBuffer',
fromBuffer: '_fromBuffer',
fromJSON: '_fromJSON',
toJSON: '_toJSON',
isValid: '_isValid',
compare: 'compare'
};
var type = new AbstractLongType(noUnpack);
Object.keys(mapping).forEach(function (name) {
if (methods[name] === undefined) {
throw new Error(f('missing method implementation: %s', name));
}
type[mapping[name]] = methods[name];
});
return type;
};
/**
* Floats.
*
*/
function FloatType() { PrimitiveType.call(this); }
util.inherits(FloatType, PrimitiveType);
FloatType.prototype._check = function (val, cb) {
var b = typeof val == 'number';
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
FloatType.prototype._read = function (tap) { return tap.readFloat(); };
FloatType.prototype._skip = function (tap) { tap.skipFloat(); };
FloatType.prototype._write = function (tap, val) {
if (typeof val != 'number') {
throwInvalidError(null, val, this);
}
tap.writeFloat(val);
};
FloatType.prototype._match = function (tap1, tap2) {
return tap1.matchFloat(tap2);
};
FloatType.prototype._updateResolver = function (resolver, type) {
if (
type instanceof FloatType ||
type instanceof LongType ||
type instanceof IntType
) {
resolver._read = type._read;
}
};
FloatType.prototype.random = function () { return RANDOM.nextFloat(1e3); };
FloatType.prototype.toJSON = function () { return 'float'; };
/**
* Doubles.
*
*/
function DoubleType() { PrimitiveType.call(this); }
util.inherits(DoubleType, PrimitiveType);
DoubleType.prototype._check = function (val, cb) {
var b = typeof val == 'number';
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
DoubleType.prototype._read = function (tap) { return tap.readDouble(); };
DoubleType.prototype._skip = function (tap) { tap.skipDouble(); };
DoubleType.prototype._write = function (tap, val) {
if (typeof val != 'number') {
throwInvalidError(null, val, this);
}
tap.writeDouble(val);
};
DoubleType.prototype._match = function (tap1, tap2) {
return tap1.matchDouble(tap2);
};
DoubleType.prototype._updateResolver = function (resolver, type) {
if (
type instanceof DoubleType ||
type instanceof FloatType ||
type instanceof LongType ||
type instanceof IntType
) {
resolver._read = type._read;
}
};
DoubleType.prototype.random = function () { return RANDOM.nextFloat(); };
DoubleType.prototype.toJSON = function () { return 'double'; };
/**
* Strings.
*
*/
function StringType() { PrimitiveType.call(this); }
util.inherits(StringType, PrimitiveType);
StringType.prototype._check = function (val, cb) {
var b = typeof val == 'string';
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
StringType.prototype._read = function (tap) { return tap.readString(); };
StringType.prototype._skip = function (tap) { tap.skipString(); };
StringType.prototype._write = function (tap, val) {
if (typeof val != 'string') {
throwInvalidError(null, val, this);
}
tap.writeString(val);
};
StringType.prototype._match = function (tap1, tap2) {
return tap1.matchString(tap2);
};
StringType.prototype._updateResolver = function (resolver, type) {
if (type instanceof StringType || type instanceof BytesType) {
resolver._read = this._read;
}
};
StringType.prototype.random = function () {
return RANDOM.nextString(RANDOM.nextInt(32));
};
StringType.prototype.toJSON = function () { return 'string'; };
/**
* Bytes.
*
* These are represented in memory as `Buffer`s rather than binary-encoded
* strings. This is more efficient (when decoding/encoding from bytes, the
* common use-case), idiomatic, and convenient.
*
* Note the coercion in `_copy`.
*
*/
function BytesType() { PrimitiveType.call(this); }
util.inherits(BytesType, PrimitiveType);
BytesType.prototype._check = function (val, cb) {
var b = Buffer.isBuffer(val);
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
BytesType.prototype._read = function (tap) { return tap.readBytes(); };
BytesType.prototype._skip = function (tap) { tap.skipBytes(); };
BytesType.prototype._write = function (tap, val) {
if (!Buffer.isBuffer(val)) {
throwInvalidError(null, val, this);
}
tap.writeBytes(val);
};
BytesType.prototype._match = function (tap1, tap2) {
return tap1.matchBytes(tap2);
};
BytesType.prototype._updateResolver = StringType.prototype._updateResolver;
BytesType.prototype._copy = function (obj, opts) {
var buf;
switch ((opts && opts.coerce) | 0) {
case 3: // Coerce buffers to strings.
this._check(obj, throwInvalidError);
return obj.toString('binary');
case 2: // Coerce strings to buffers.
if (typeof obj != 'string') {
throw new Error(f('cannot coerce to buffer: %j', obj));
}
buf = new Buffer(obj, 'binary');
this._check(buf, throwInvalidError);
return buf;
case 1: // Coerce buffer JSON representation to buffers.
if (!obj || obj.type !== 'Buffer' || !(obj.data instanceof Array)) {
throw new Error(f('cannot coerce to buffer: %j', obj));
}
buf = new Buffer(obj.data);
this._check(buf, throwInvalidError);
return buf;
default: // Copy buffer.
this._check(obj, throwInvalidError);
return new Buffer(obj);
}
};
BytesType.prototype.compare = Buffer.compare;
BytesType.prototype.random = function () {
return RANDOM.nextBuffer(RANDOM.nextInt(32));
};
BytesType.prototype.toJSON = function () { return 'bytes'; };
/**
* Avro unions.
*
* Unions are represented in memory similarly to their JSON representation
* (i.e. inside an object with single key the name of the contained type).
*
* This is not ideal, but is the most efficient way to unambiguously support
* all unions. Here are a few reasons why the wrapping object is necessary:
*
* + Unions with multiple number types would have undefined behavior, unless
* numbers are wrapped (either everywhere, leading to large performance and
* convenience costs; or only when necessary inside unions, making it hard to
* understand when numbers are wrapped or not).
* + Fixed types would have to be wrapped to be distinguished from bytes.
* + Using record's constructor names would work (after a slight change to use
* the fully qualified name), but would mean that generic objects could no
* longer be valid records (making it inconvenient to do simple things like
* creating new records).
*
* Lore: In the past (until d304cab), there used to be an "unwrapped union
* type" which directly exposed its values, without the wrapping object
* (similarly to Avro's python implementation). It was removed to keep all
* representations consistent and make this library simpler to understand
* (conversions, e.g. for schema evolution, between representations were
* particularly confusing). Encoding was also much slower (worst case
* complexity linear in the number of types in the union).
*
*/
function UnionType(attrs, opts) {
if (!(attrs instanceof Array)) {
throw new Error(f('non-array union schema: %j', attrs));
}
if (!attrs.length) {
throw new Error('empty union');
}
opts = getOpts(attrs, opts);
Type.call(this);
this._types = attrs.map(function (obj) { return createType(obj, opts); });
this._indices = {};
this._types.forEach(function (type, i) {
if (type instanceof UnionType) {
throw new Error('unions cannot be directly nested');
}
var name = type._name || getTypeName(type);
if (this._indices[name] !== undefined) {
throw new Error(f('duplicate union name: %j', name));
}
this._indices[name] = i;
}, this);
this._constructors = this._types.map(function (type) {
// jshint -W054
var name = type._name || getTypeName(type);
if (name === 'null') {
return null;
}
var body;
if (~name.indexOf('.')) { // Qualified name.
body = 'this[\'' + name + '\'] = val;';
} else {
body = 'this.' + name + ' = val;';
}
return new Function('val', body);
});
}
util.inherits(UnionType, Type);
UnionType.prototype._check = function (val, cb) {
var b = false;
if (val === null) {
// Shortcut type lookup in this case.
b = this._indices['null'] !== undefined;
} else if (typeof val == 'object') {
var keys = Object.keys(val);
if (keys.length === 1) {
// We require a single key here to ensure that writes are correct and
// efficient as soon as a record passes this check.
var name = keys[0];
var index = this._indices[name];
if (index !== undefined) {
PATH.push(name);
b = this._types[index]._check(val[name], cb);
PATH.pop();
return b;
}
}
}
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
UnionType.prototype._read = function (tap) {
var index = tap.readLong();
var Class = this._constructors[index];
if (Class) {
return new Class(this._types[index]._read(tap));
} else if (Class === null) {
return null;
} else {
throw new Error(f('invalid union index: %s', index));
}
};
UnionType.prototype._skip = function (tap) {
this._types[tap.readLong()]._skip(tap);
};
UnionType.prototype._write = function (tap, val) {
var index, keys, name;
if (val === null) {
index = this._indices['null'];
if (index === undefined) {
throwInvalidError(null, val, this);
}
tap.writeLong(index);
} else {
keys = Object.keys(val);
if (keys.length === 1) {
name = keys[0];
index = this._indices[name];
}
if (index === undefined) {
throwInvalidError(null, val, this);
}
tap.writeLong(index);
this._types[index]._write(tap, val[name]);
}
};
UnionType.prototype._match = function (tap1, tap2) {
var n1 = tap1.readLong();
var n2 = tap2.readLong();
if (n1 === n2) {
return this._types[n1]._match(tap1, tap2);
} else {
return n1 < n2 ? -1 : 1;
}
};
UnionType.prototype._updateResolver = function (resolver, type, opts) {
// jshint -W083
// (The loop exits after the first function is created.)
var i, l, typeResolver, Class;
for (i = 0, l = this._types.length; i < l; i++) {
try {
typeResolver = this._types[i].createResolver(type, opts);
} catch (err) {
continue;
}
Class = this._constructors[i];
if (Class) {
resolver._read = function (tap) {
return new Class(typeResolver._read(tap));
};
} else {
resolver._read = function () { return null; };
}
return;
}
};
UnionType.prototype._copy = function (val, opts) {
var wrap = opts && opts.wrap | 0;
if (wrap === 2) {
// Promote into first type (used for schema defaults).
if (val === null && this._constructors[0] === null) {
return null;
}
return new this._constructors[0](this._types[0]._copy(val, opts));
}
if (val === null && this._indices['null'] !== undefined) {
return null;
}
var i, l, obj;
if (wrap === 1) {
// Promote into first match (convenience, slow).
i = 0;
l = this._types.length;
while (i < l && obj === undefined) {
try {
obj = this._types[i]._copy(val, opts);
} catch (err) {
i++;
}
}
} else if (typeof val == 'object') {
var keys = Object.keys(val);
if (keys.length === 1) {
var name = keys[0];
i = this._indices[name];
if (i === undefined) {
// We are a bit more flexible than in `_check` here since we have
// to deal with other serializers being less strict, so we fall
// back to looking up unqualified names.
var j, type;
for (j = 0, l = this._types.length; j < l; j++) {
type = this._types[j];
if (type._name && name === unqualify(type._name)) {
i = j;
break;
}
}
}
if (i !== undefined) {
obj = this._types[i]._copy(val[name], opts);
}
}
}
if (obj !== undefined) {
return new this._constructors[i](obj);
}
throwInvalidError(null, val, this);
};
UnionType.prototype.compare = function (val1, val2) {
var name1 = val1 === null ? 'null' : Object.keys(val1)[0];
var name2 = val2 === null ? 'null' : Object.keys(val2)[0];
var index = this._indices[name1];
if (name1 === name2) {
return name1 === 'null' ?
0 :
this._types[index].compare(val1[name1], val2[name1]);
} else {
return utils.compare(index, this._indices[name2]);
}
};
UnionType.prototype.getTypes = function () { return this._types.slice(); };
UnionType.prototype.random = function () {
var index = RANDOM.nextInt(this._types.length);
var Class = this._constructors[index];
if (!Class) {
return null;
}
return new Class(this._types[index].random());
};
UnionType.prototype.toJSON = function () { return this._types; };
/**
* Avro enum type.
*
* Represented as strings (with allowed values from the set of symbols). Using
* integers would be a reasonable option, but the performance boost is arguably
* offset by the legibility cost and the extra deviation from the JSON encoding
* convention.
*
* An integer representation can still be used (e.g. for compatibility with
* TypeScript `enum`s) by overriding the `EnumType` with a `LongType` (e.g. via
* `parse`'s registry).
*
*/
function EnumType(attrs, opts) {
if (!(attrs.symbols instanceof Array) || !attrs.symbols.length) {
throw new Error(f('invalid %j enum symbols: %j', attrs.name, attrs));
}
opts = getOpts(attrs, opts);
var resolutions = resolveNames(attrs, opts.namespace);
this._name = resolutions.name;
this._symbols = attrs.symbols;
this._aliases = resolutions.aliases;
Type.call(this, opts.registry);
this._indices = {};
this._symbols.forEach(function (symbol, i) {
if (!NAME_PATTERN.test(symbol)) {
throw new Error(f('invalid %s symbol: %j', this, symbol));
}
if (this._indices[symbol] !== undefined) {
throw new Error(f('duplicate %s symbol: %j', this, symbol));
}
this._indices[symbol] = i;
}, this);
}
util.inherits(EnumType, Type);
EnumType.prototype._check = function (val, cb) {
var b = this._indices[val] !== undefined;
if (!b && cb) {
cb(PATH.slice(), val, this);
}
return b;
};
EnumType.prototype._read = function (tap) {
var index = tap.readLong();
var symbol = this._symbols[index];
if (symbol === undefined) {
throw new Error(f('invalid %s enum index: %s', this._name, index));
}
return symbol;
};
EnumType.prototype._skip = function (tap) { tap.skipLong(); };
EnumType.prototype._write = function (tap, val) {
var index = this._indices[val];
if (index === undefined) {
throwInvalidError(null, val, this);
}
tap.writeLong(index);
};
EnumType.prototype._match = function (tap1, tap2) {
return tap1.matchLong(tap2);
};
EnumType.prototype.compare = function (val1, val2) {
return utils.compare(this._indices[val1], this._indices[val2]);
};
EnumType.prototype._updateResolver = function (resolver, type) {