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/*
*
* Copyright 2014, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
var _ = require('underscore');
var client = require('./client.js');
var common = require('./common.js');
var EventEmitter = require('events').EventEmitter;
var stream = require('stream');
var Readable = stream.Readable;
var Writable = stream.Writable;
var Duplex = stream.Duplex;
var util = require('util');
function forwardEvent(fromEmitter, toEmitter, event) {
fromEmitter.on(event, function forward() {
_.partial(toEmitter.emit, event).apply(toEmitter, arguments);
});
}
util.inherits(ClientReadableObjectStream, Readable);
/**
* Class for representing a gRPC server streaming call as a Node stream on the
* client side. Extends from stream.Readable.
* @constructor
* @param {stream} stream Underlying binary Duplex stream for the call
* @param {function(Buffer)} deserialize Function for deserializing binary data
* @param {object} options Stream options
*/
function ClientReadableObjectStream(stream, deserialize, options) {
options = _.extend(options, {objectMode: true});
Readable.call(this, options);
this._stream = stream;
var self = this;
forwardEvent(stream, this, 'status');
forwardEvent(stream, this, 'metadata');
this._stream.on('data', function forwardData(chunk) {
if (!self.push(deserialize(chunk))) {
self._stream.pause();
}
});
this._stream.pause();
}
util.inherits(ClientWritableObjectStream, Writable);
/**
* Class for representing a gRPC client streaming call as a Node stream on the
* client side. Extends from stream.Writable.
* @constructor
* @param {stream} stream Underlying binary Duplex stream for the call
* @param {function(*):Buffer} serialize Function for serializing objects
* @param {object} options Stream options
*/
function ClientWritableObjectStream(stream, serialize, options) {
options = _.extend(options, {objectMode: true});
Writable.call(this, options);
this._stream = stream;
this._serialize = serialize;
forwardEvent(stream, this, 'status');
forwardEvent(stream, this, 'metadata');
this.on('finish', function() {
this._stream.end();
});
}
util.inherits(ClientBidiObjectStream, Duplex);
/**
* Class for representing a gRPC bidi streaming call as a Node stream on the
* client side. Extends from stream.Duplex.
* @constructor
* @param {stream} stream Underlying binary Duplex stream for the call
* @param {function(*):Buffer} serialize Function for serializing objects
* @param {function(Buffer)} deserialize Function for deserializing binary data
* @param {object} options Stream options
*/
function ClientBidiObjectStream(stream, serialize, deserialize, options) {
options = _.extend(options, {objectMode: true});
Duplex.call(this, options);
this._stream = stream;
this._serialize = serialize;
var self = this;
forwardEvent(stream, this, 'status');
forwardEvent(stream, this, 'metadata');
this._stream.on('data', function forwardData(chunk) {
if (!self.push(deserialize(chunk))) {
self._stream.pause();
}
});
this._stream.pause();
this.on('finish', function() {
this._stream.end();
});
}
/**
* _read implementation for both types of streams that allow reading.
* @this {ClientReadableObjectStream|ClientBidiObjectStream}
* @param {number} size Ignored
*/
function _read(size) {
this._stream.resume();
}
/**
* See docs for _read
*/
ClientReadableObjectStream.prototype._read = _read;
/**
* See docs for _read
*/
ClientBidiObjectStream.prototype._read = _read;
/**
* _write implementation for both types of streams that allow writing
* @this {ClientWritableObjectStream|ClientBidiObjectStream}
* @param {*} chunk The value to write to the stream
* @param {string} encoding Ignored
* @param {function(Error)} callback Callback to call when finished writing
*/
function _write(chunk, encoding, callback) {
this._stream.write(this._serialize(chunk), encoding, callback);
}
/**
* See docs for _write
*/
ClientWritableObjectStream.prototype._write = _write;
/**
* See docs for _write
*/
ClientBidiObjectStream.prototype._write = _write;
/**
* Get a function that can make unary requests to the specified method.
* @param {string} method The name of the method to request
* @param {function(*):Buffer} serialize The serialization function for inputs
* @param {function(Buffer)} deserialize The deserialization function for
* outputs
* @return {Function} makeUnaryRequest
*/
function makeUnaryRequestFunction(method, serialize, deserialize) {
/**
* Make a unary request with this method on the given channel with the given
* argument, callback, etc.
* @this {SurfaceClient} Client object. Must have a channel member.
* @param {*} argument The argument to the call. Should be serializable with
* serialize
* @param {function(?Error, value=)} callback The callback to for when the
* response is received
* @param {array=} metadata Array of metadata key/value pairs to add to the
* call
* @param {(number|Date)=} deadline The deadline for processing this request.
* Defaults to infinite future
* @return {EventEmitter} An event emitter for stream related events
*/
function makeUnaryRequest(argument, callback, metadata, deadline) {
var stream = client.makeRequest(this.channel, method, metadata, deadline);
var emitter = new EventEmitter();
forwardEvent(stream, emitter, 'status');
forwardEvent(stream, emitter, 'metadata');
stream.write(serialize(argument));
stream.end();
stream.on('data', function forwardData(chunk) {
try {
callback(null, deserialize(chunk));
} catch (e) {
callback(e);
}
});
return emitter;
}
return makeUnaryRequest;
}
/**
* Get a function that can make client stream requests to the specified method.
* @param {string} method The name of the method to request
* @param {function(*):Buffer} serialize The serialization function for inputs
* @param {function(Buffer)} deserialize The deserialization function for
* outputs
* @return {Function} makeClientStreamRequest
*/
function makeClientStreamRequestFunction(method, serialize, deserialize) {
/**
* Make a client stream request with this method on the given channel with the
* given callback, etc.
* @this {SurfaceClient} Client object. Must have a channel member.
* @param {function(?Error, value=)} callback The callback to for when the
* response is received
* @param {array=} metadata Array of metadata key/value pairs to add to the
* call
* @param {(number|Date)=} deadline The deadline for processing this request.
* Defaults to infinite future
* @return {EventEmitter} An event emitter for stream related events
*/
function makeClientStreamRequest(callback, metadata, deadline) {
var stream = client.makeRequest(this.channel, method, metadata, deadline);
var obj_stream = new ClientWritableObjectStream(stream, serialize, {});
stream.on('data', function forwardData(chunk) {
try {
callback(null, deserialize(chunk));
} catch (e) {
callback(e);
}
});
return obj_stream;
}
return makeClientStreamRequest;
}
/**
* Get a function that can make server stream requests to the specified method.
* @param {string} method The name of the method to request
* @param {function(*):Buffer} serialize The serialization function for inputs
* @param {function(Buffer)} deserialize The deserialization function for
* outputs
* @return {Function} makeServerStreamRequest
*/
function makeServerStreamRequestFunction(method, serialize, deserialize) {
/**
* Make a server stream request with this method on the given channel with the
* given argument, etc.
* @this {SurfaceClient} Client object. Must have a channel member.
* @param {*} argument The argument to the call. Should be serializable with
* serialize
* @param {array=} metadata Array of metadata key/value pairs to add to the
* call
* @param {(number|Date)=} deadline The deadline for processing this request.
* Defaults to infinite future
* @return {EventEmitter} An event emitter for stream related events
*/
function makeServerStreamRequest(argument, metadata, deadline) {
var stream = client.makeRequest(this.channel, method, metadata, deadline);
var obj_stream = new ClientReadableObjectStream(stream, deserialize, {});
stream.write(serialize(argument));
stream.end();
return obj_stream;
}
return makeServerStreamRequest;
}
/**
* Get a function that can make bidirectional stream requests to the specified
* method.
* @param {string} method The name of the method to request
* @param {function(*):Buffer} serialize The serialization function for inputs
* @param {function(Buffer)} deserialize The deserialization function for
* outputs
* @return {Function} makeBidiStreamRequest
*/
function makeBidiStreamRequestFunction(method, serialize, deserialize) {
/**
* Make a bidirectional stream request with this method on the given channel.
* @this {SurfaceClient} Client object. Must have a channel member.
* @param {array=} metadata Array of metadata key/value pairs to add to the
* call
* @param {(number|Date)=} deadline The deadline for processing this request.
* Defaults to infinite future
* @return {EventEmitter} An event emitter for stream related events
*/
function makeBidiStreamRequest(metadata, deadline) {
var stream = client.makeRequest(this.channel, method, metadata, deadline);
var obj_stream = new ClientBidiObjectStream(stream,
serialize,
deserialize,
{});
return obj_stream;
}
return makeBidiStreamRequest;
}
/**
* Map with short names for each of the requester maker functions. Used in
* makeClientConstructor
*/
var requester_makers = {
unary: makeUnaryRequestFunction,
server_stream: makeServerStreamRequestFunction,
client_stream: makeClientStreamRequestFunction,
bidi: makeBidiStreamRequestFunction
}
/**
* Creates a constructor for clients for the given service
* @param {ProtoBuf.Reflect.Service} service The service to generate a client
* for
* @return {function(string, Object)} New client constructor
*/
function makeClientConstructor(service) {
var prefix = '/' + common.fullyQualifiedName(service) + '/';
/**
* Create a client with the given methods
* @constructor
* @param {string} address The address of the server to connect to
* @param {Object} options Options to pass to the underlying channel
*/
function SurfaceClient(address, options) {
this.channel = new client.Channel(address, options);
}
_.each(service.children, function(method) {
var method_type;
if (method.requestStream) {
if (method.responseStream) {
method_type = 'bidi';
} else {
method_type = 'client_stream';
}
} else {
if (method.responseStream) {
method_type = 'server_stream';
} else {
method_type = 'unary';
}
}
SurfaceClient.prototype[method.name] = requester_makers[method_type](
prefix + method.name,
common.serializeCls(method.resolvedRequestType.build()),
common.deserializeCls(method.resolvedResponseType.build()));
});
SurfaceClient.service = service;
return SurfaceClient;
}
exports.makeClientConstructor = makeClientConstructor;
/**
* See docs for client.status
*/
exports.status = client.status;
/**
* See docs for client.callError
*/
exports.callError = client.callError;
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