src/com/cognitect/transit/impl/writer.js
// Copyright 2014 Cognitect. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
goog.provide("com.cognitect.transit.impl.writer");
goog.require("com.cognitect.transit.util");
goog.require("com.cognitect.transit.caching");
goog.require("com.cognitect.transit.handlers");
goog.require("com.cognitect.transit.types");
goog.require("com.cognitect.transit.delimiters");
goog.require("goog.math.Long");
goog.scope(function() {
var writer = com.cognitect.transit.impl.writer,
util = com.cognitect.transit.util,
caching = com.cognitect.transit.caching,
handlers = com.cognitect.transit.handlers,
types = com.cognitect.transit.types,
d = com.cognitect.transit.delimiters,
Long = goog.math.Long;
writer.escape = function(string) {
if(string.length > 0) {
var c = string.charAt(0);
if(c === d.ESC || c === d.SUB || c === d.RES) {
return d.ESC+string;
} else {
return string;
}
} else {
return string;
}
};
/**
* @constructor
*/
writer.JSONMarshaller = function(opts) {
this.opts = opts || {};
this.preferStrings = this.opts["preferStrings"] != null ? this.opts["preferStrings"] : true;
this.objectBuilder = this.opts["objectBuilder"] || null;
this.handlers = new handlers.Handlers();
var optsHandlers = this.opts["handlers"];
if(optsHandlers) {
if(util.isArray(optsHandlers) || !optsHandlers.forEach) {
throw new Error("transit writer \"handlers\" option must be a map");
}
var self = this;
optsHandlers.forEach(function(v, k) {
if(k !== undefined) {
self.handlers.set(k, v);
} else {
throw new Error("Cannot create handler for JavaScript undefined");
}
});
}
// Multiple JS context helper
this.handlerForForeign = this.opts["handlerForForeign"];
this.unpack = this.opts["unpack"] || function(x) {
if(types.isArrayMap(x) && x.backingMap === null) {
return x._entries;
} else {
return false;
}
};
this.verbose = (this.opts && this.opts["verbose"]) || false;
};
writer.JSONMarshaller.prototype.handler = function(obj) {
var h = this.handlers.get(handlers.constructor(obj));
if(h != null) {
return h;
} else {
var tag = obj && obj["transitTag"];
if(tag) {
return this.handlers.get(tag)
} else {
return null;
}
}
};
writer.JSONMarshaller.prototype.registerHandler = function(ctor, handler) {
this.handlers.set(ctor, handler);
};
writer.JSONMarshaller.prototype.emitNil = function(asMapKey, cache) {
if(asMapKey) {
return this.emitString(d.ESC, "_", "", asMapKey, cache);
} else {
return null;
}
};
writer.JSONMarshaller.prototype.emitString = function(prefix, tag, s, asMapKey, cache) {
var string = prefix+tag+s;
if(cache) {
return cache.write(string, asMapKey);
} else {
return string;
}
};
writer.JSONMarshaller.prototype.emitBoolean = function(b, asMapKey, cache) {
if(asMapKey) {
var s = b.toString();
return this.emitString(d.ESC, "?", s[0], asMapKey, cache);
} else {
return b;
}
};
writer.JSONMarshaller.prototype.emitInteger = function(i, asMapKey, cache) {
if(i === Infinity) {
return this.emitString(d.ESC, "z", "INF", asMapKey, cache);
} else if(i === -Infinity) {
return this.emitString(d.ESC, "z", "-INF", asMapKey, cache);
} else if(isNaN(i)) {
return this.emitString(d.ESC, "z", "NaN", asMapKey, cache);
} else if(asMapKey || (typeof i === "string") || (i instanceof Long)) {
return this.emitString(d.ESC, "i", i.toString(), asMapKey, cache);
} else {
return i;
}
};
writer.JSONMarshaller.prototype.emitDouble = function(d, asMapKey, cache) {
if(asMapKey) {
return this.emitString(d.ESC, "d", d, asMapKey, cache);
} else {
return d;
}
};
writer.JSONMarshaller.prototype.emitBinary = function(b, asMapKey, cache) {
return this.emitString(d.ESC, "b", b, asMapKey, cache);
};
writer.JSONMarshaller.prototype.emitQuoted = function(em, obj, cache) {
if(em.verbose) {
var ret = {},
k = this.emitString(d.ESC_TAG, "'", "", true, cache);
ret[k] = writer.marshal(this, obj, false, cache);
return ret;
} else {
return [this.emitString(d.ESC_TAG, "'", "", true, cache), writer.marshal(this, obj, false, cache)];
}
};
writer.emitObjects = function(em, iterable, cache) {
var ret = [];
if(util.isArray(iterable)) {
for(var i = 0; i < iterable.length; i++) {
ret.push(writer.marshal(em, iterable[i], false, cache));
}
} else {
iterable.forEach(function(v, i) {
ret.push(writer.marshal(em, v, false, cache));
});
}
return ret;
};
writer.emitArray = function(em, iterable, skip, cache) {
return writer.emitObjects(em, iterable, cache);
};
writer.isStringableKey = function(em, k) {
if(typeof k !== "string") {
var h = em.handler(k);
return h && h.tag(k).length === 1;
} else {
return true;
}
};
writer.stringableKeys = function(em, obj) {
var arr = em.unpack(obj),
stringableKeys = true;
if(arr) {
for(var i = 0; i < arr.length; i+=2) {
stringableKeys = writer.isStringableKey(em, arr[i]);
if(!stringableKeys) {
break;
}
}
return stringableKeys;
} else if(obj.keys) {
var iter = obj.keys(),
step = null;
if(iter.next) {
step = iter.next();
while(!step.done) {
stringableKeys = writer.isStringableKey(em, step.value);
if(!stringableKeys) {
break;
}
step = iter.next();
}
return stringableKeys;
}
}
if(obj.forEach) {
obj.forEach(function(v, k) {
stringableKeys = stringableKeys && writer.isStringableKey(em, k);
});
return stringableKeys;
} else {
throw new Error("Cannot walk keys of object type " + handlers.constructor(obj).name);
}
};
writer.isForeignObject = function(x) {
if(x.constructor["transit$isObject"]) {
return true;
}
var ret = x.constructor.toString(),
ret = ret.substr('function '.length),
ret = ret.substr(0, ret.indexOf('(')),
isObject = ret == "Object";
if(typeof Object.defineProperty != "undefined") {
Object.defineProperty(x.constructor, "transit$isObject", {
value: isObject,
enumerable: false
});
} else {
x.constructor["transit$isObject"] = isObject;
}
return isObject;
};
writer.emitMap = function(em, obj, skip, cache) {
if((obj.constructor === Object) ||
(obj.forEach != null) ||
(em.handlerForForeign && writer.isForeignObject(obj))) {
if(em.verbose) {
if(obj.forEach != null) {
if(writer.stringableKeys(em, obj)) {
var ret = {};
obj.forEach(function(v, k) {
ret[writer.marshal(em, k, true, false)] = writer.marshal(em, v, false, cache);
});
return ret;
} else {
var arr = em.unpack(obj),
rep = [],
tag = em.emitString(d.ESC_TAG, "cmap", "", true, cache);
if(arr) {
for(var i = 0; i < arr.length; i+=2) {
rep.push(writer.marshal(em, arr[i], true, false));
rep.push(writer.marshal(em, arr[i+1], false, cache));
}
} else {
obj.forEach(function(v, k) {
rep.push(writer.marshal(em, k, true, false));
rep.push(writer.marshal(em, v, false, cache));
});
}
var ret = {};
ret[tag] = rep;
return ret;
}
} else {
var ret = {},
ks = util.objectKeys(obj);
for(var i = 0; i < ks.length; i++) {
ret[writer.marshal(em, ks[i], true, false)] = writer.marshal(em, obj[ks[i]], false, cache);
}
return ret;
}
} else {
if(obj.forEach != null) {
if(writer.stringableKeys(em, obj)) {
var arr = em.unpack(obj),
ret = ["^ "];
if(arr) {
for(var i = 0; i < arr.length; i+=2) {
ret.push(writer.marshal(em, arr[i], true, cache));
ret.push(writer.marshal(em, arr[i+1], false, cache));
}
} else {
obj.forEach(function(v, k) {
ret.push(writer.marshal(em, k, true, cache));
ret.push(writer.marshal(em, v, false, cache));
});
}
return ret;
} else {
var arr = em.unpack(obj),
rep = [],
tag = em.emitString(d.ESC_TAG, "cmap", "", true, cache);
if(arr) {
for(var i = 0; i < arr.length; i+=2) {
rep.push(writer.marshal(em, arr[i], true, cache));
rep.push(writer.marshal(em, arr[i+1], false, cache));
}
} else {
obj.forEach(function(v, k) {
rep.push(writer.marshal(em, k, true, cache));
rep.push(writer.marshal(em, v, false, cache));
});
}
return [tag, rep];
}
} else {
var ret = ["^ "],
ks = util.objectKeys(obj);
for(var i = 0; i < ks.length; i++) {
ret.push(writer.marshal(em, ks[i], true, cache));
ret.push(writer.marshal(em, obj[ks[i]], false, cache));
}
return ret;
}
}
} else if(em.objectBuilder != null) {
return em.objectBuilder(obj, function(k) { return writer.marshal(em, k, true, cache); },
function(v) { return writer.marshal(em, v, false, cache); });
} else {
var name = handlers.constructor(obj).name,
err = new Error("Cannot write " + name);
err.data = {obj: obj, type: name};
throw err;
}
};
writer.emitTaggedMap = function(em, tag, rep, skip, cache) {
if(em.verbose) {
var ret = {};
ret[em.emitString(d.ESC_TAG, tag, "", true, cache)] = writer.marshal(em, rep, false, cache);
return ret;
} else {
return [em.emitString(d.ESC_TAG, tag, "", true, cache), writer.marshal(em, rep, false, cache)];
}
};
writer.emitEncoded = function(em, h, tag, rep, obj, asMapKey, cache) {
if(tag.length === 1) {
if(typeof rep === "string") {
return em.emitString(d.ESC, tag, rep, asMapKey, cache);
} else if(asMapKey || em.preferStrings) {
var vh = em.verbose && h.getVerboseHandler();
if(vh) {
tag = vh.tag(obj);
rep = vh.stringRep(obj, vh);
} else {
rep = h.stringRep(obj, h);
}
if(rep !== null) {
return em.emitString(d.ESC, tag, rep, asMapKey, cache);
} else {
var err = new Error("Tag \""+tag+"\" cannot be encoded as string");
err.data = {tag: tag, rep: rep, obj: obj};
throw err;
}
} else {
return writer.emitTaggedMap(em, tag, rep, asMapKey, cache);
}
} else {
return writer.emitTaggedMap(em, tag, rep, asMapKey, cache);
}
}
writer.marshal = function(em, obj, asMapKey, cache) {
var h = em.handler(obj) || (em.handlerForForeign ? em.handlerForForeign(obj, em.handlers) : null),
tag = h ? h.tag(obj) : null,
rep = h ? h.rep(obj) : null;
if(h != null && tag != null) {
switch(tag) {
case "_":
return em.emitNil(asMapKey, cache);
break;
case "s":
return em.emitString("", "", writer.escape(rep), asMapKey, cache);
break;
case "?":
return em.emitBoolean(rep, asMapKey, cache);
break;
case "i":
return em.emitInteger(rep, asMapKey, cache);
break;
case "d":
return em.emitDouble(rep, asMapKey, cache);
break;
case "b":
return em.emitBinary(rep, asMapKey, cache);
break;
case "'":
return em.emitQuoted(em, rep, cache);
break;
case "array":
return writer.emitArray(em, rep, asMapKey, cache);
break;
case "map":
return writer.emitMap(em, rep, asMapKey, cache);
break;
default:
return writer.emitEncoded(em, h, tag, rep, obj, asMapKey, cache);
break;
}
} else {
var name = handlers.constructor(obj).name,
err = new Error("Cannot write " + name);
err.data = {obj: obj, type: name};
throw err;
}
};
writer.maybeQuoted = function(em, obj) {
var h = em.handler(obj) || (em.handlerForForeign ? em.handlerForForeign(obj, em.handlers) : null);
if(h != null) {
if(h.tag(obj).length === 1) {
return types.quoted(obj);
} else {
return obj;
}
} else {
var name = handlers.constructor(obj).name,
err = new Error("Cannot write " + name);
err.data = {obj: obj, type: name};
throw err;
}
};
writer.marshalTop = function(em, obj, asMapKey, cache) {
return JSON.stringify(writer.marshal(em, writer.maybeQuoted(em, obj), asMapKey, cache));
};
/**
* @constructor
*/
writer.Writer = function(marshaller, options) {
this._marshaller = marshaller;
this.options = options || {};
if(this.options["cache"] === false) {
this.cache = null;
} else {
this.cache = this.options["cache"] ? this.options["cache"] : new caching.WriteCache();
}
};
writer.Writer.prototype.marshaller = function() {
return this._marshaller;
};
writer.Writer.prototype["marshaller"] = writer.Writer.prototype.marshaller;
writer.Writer.prototype.write = function(obj, opts) {
var ret = null,
ropts = opts || {},
asMapKey = ropts["asMapKey"] || false,
cache = this._marshaller.verbose ? false : this.cache;
if(ropts["marshalTop"] === false) {
ret = writer.marshal(this._marshaller, obj, asMapKey, cache)
} else {
ret = writer.marshalTop(this._marshaller, obj, asMapKey, cache)
}
if(this.cache != null) {
this.cache.clear();
}
return ret;
};
writer.Writer.prototype["write"] = writer.Writer.prototype.write;
writer.Writer.prototype.register = function(type, handler) {
this._marshaller.registerHandler(type, handler);
};
writer.Writer.prototype["register"] = writer.Writer.prototype.register;
});
transit-js: src/com/cognitect/transit/impl/writer.js