view vamp-server/convert.cpp @ 116:d15cb1151d76

Add JSON support directly to the server. Had hoped to avoid this (using Capnp as canonical in the server and then converting externally as necessary) but it's just too useful for debugging purposes when bundled with client app

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

#include "vamp-json/VampJson.h"
#include "vamp-capnp/VampnProto.h"
#include "vamp-support/RequestOrResponse.h"
#include "vamp-support/PreservingPluginHandleMapper.h"

#include <iostream>
#include <sstream>
#include <stdexcept>

#include <capnp/serialize.h>

using namespace std;
using namespace json11;
using namespace piper_vamp;

void usage()
{
    string myname = "piper-convert";
    cerr << "\n" << myname <<
        ": Validate and convert Piper request and response messages\n\n"
        "    Usage: " << myname << " [-i <informat>] [-o <outformat>] request\n"
        "           " << myname << " [-i <informat>] [-o <outformat>] response\n\n"
        "    where\n"
        "       <informat>: the format to read from stdin\n"
        "           (\"json\" or \"capnp\", default is \"json\")\n"
        "       <outformat>: the format to convert to and write to stdout\n"
        "           (\"json\", \"json-b64\" or \"capnp\", default is \"json\")\n"
        "       request|response: whether messages are Vamp request or response type\n\n"
        "If <informat> and <outformat> differ, convert from <informat> to <outformat>.\n"
        "If <informat> and <outformat> are the same, just check validity of incoming\n"
        "messages and pass them to output.\n\n"
        "Specifying \"json-b64\" as output format forces base64 encoding for process and\n"
        "feature blocks, unlike the \"json\" output format which uses text encoding.\n"
        "The \"json\" input format accepts either.\n\n";

    exit(2);
}

Json
convertRequestJson(string input, string &err)
{
    Json j = Json::parse(input, err);
    if (err != "") {
        err = "invalid json: " + err;
        return {};
    }
    if (!j.is_object()) {
        err = "object expected at top level";
    } else if (!j["method"].is_string()) {
        err = "string expected for method field";
    } else if (!j["params"].is_null() && !j["params"].is_object()) {
        err = "object expected for params field";
    }
    return j;
}

Json
convertResponseJson(string input, string &err)
{
    Json j = Json::parse(input, err);
    if (err != "") {
        err = "invalid json: " + err;
        return {};
    }
    if (!j.is_object()) {
        err = "object expected at top level";
    } else {
        if (!j["result"].is_object()) {
            if (!j["error"].is_object()) {
                err = "expected either result or error object";
            }
        }
    }
    return j;
}

//!!! Lots of potential for refactoring the conversion classes based
//!!! on the common matter in the following eight functions...

PreservingPluginHandleMapper mapper;

static RequestOrResponse::RpcId
readJsonId(const Json &j)
{
    RequestOrResponse::RpcId id;

    if (j["id"].is_number()) {
        id.type = RequestOrResponse::RpcId::Number;
        id.number = j["id"].number_value();
    } else if (j["id"].is_string()) {
        id.type = RequestOrResponse::RpcId::Tag;
        id.tag = j["id"].string_value();
    } else {
        id.type = RequestOrResponse::RpcId::Absent;
    }

    return id;
}

static Json
writeJsonId(const RequestOrResponse::RpcId &id)
{
    if (id.type == RequestOrResponse::RpcId::Number) {
        return id.number;
    } else if (id.type == RequestOrResponse::RpcId::Tag) {
        return id.tag;
    } else {
        return Json();
    }
}

template <typename Reader>
static RequestOrResponse::RpcId
readCapnpId(const Reader &r)
{
    int number;
    string tag;
    switch (r.getId().which()) {
    case piper::RpcRequest::Id::Which::NUMBER:
        number = r.getId().getNumber();
        return { RequestOrResponse::RpcId::Number, number, "" };
    case piper::RpcRequest::Id::Which::TAG:
        tag = r.getId().getTag();
        return { RequestOrResponse::RpcId::Tag, 0, tag };
    case piper::RpcRequest::Id::Which::NONE:
        return { RequestOrResponse::RpcId::Absent, 0, "" };
    }
    return {};
}

template <typename Builder>
static void
buildCapnpId(Builder &b, const RequestOrResponse::RpcId &id)
{
    switch (id.type) {
    case RequestOrResponse::RpcId::Number:
        b.getId().setNumber(id.number);
        break;
    case RequestOrResponse::RpcId::Tag:
        b.getId().setTag(id.tag);
        break;
    case RequestOrResponse::RpcId::Absent:
        b.getId().setNone();
        break;
    }
}

RequestOrResponse
readRequestJson(string &err)
{
    RequestOrResponse rr;
    rr.direction = RequestOrResponse::Request;

    string input;
    if (!getline(cin, input)) {
        // the EOF case, not actually an error
        rr.type = RRType::NotValid;
        return rr;
    }
    
    Json j = convertRequestJson(input, err);
    if (err != "") return {};

    rr.type = VampJson::getRequestResponseType(j, err);
    if (err != "") return {};

    rr.id = readJsonId(j);

    VampJson::BufferSerialisation serialisation =
        VampJson::BufferSerialisation::Array;

    switch (rr.type) {

    case RRType::List:
        VampJson::toRpcRequest_List(j, err); // type check only
        break;
    case RRType::Load:
        rr.loadRequest = VampJson::toRpcRequest_Load(j, err);
        break;
    case RRType::Configure:
        rr.configurationRequest = VampJson::toRpcRequest_Configure(j, mapper, err);
        break;
    case RRType::Process:
        rr.processRequest = VampJson::toRpcRequest_Process(j, mapper, serialisation, err);
        break;
    case RRType::Finish:
        rr.finishRequest = VampJson::toRpcRequest_Finish(j, mapper, err);
        break;
    case RRType::NotValid:
        break;
    }

    return rr;
}

void
writeRequestJson(RequestOrResponse &rr, bool useBase64)
{
    Json j;

    VampJson::BufferSerialisation serialisation =
        (useBase64 ?
         VampJson::BufferSerialisation::Base64 :
         VampJson::BufferSerialisation::Array);

    Json id = writeJsonId(rr.id);
    
    switch (rr.type) {

    case RRType::List:
        j = VampJson::fromRpcRequest_List(id);
        break;
    case RRType::Load:
        j = VampJson::fromRpcRequest_Load(rr.loadRequest, id);
        break;
    case RRType::Configure:
        j = VampJson::fromRpcRequest_Configure(rr.configurationRequest, mapper, id);
        break;
    case RRType::Process:
        j = VampJson::fromRpcRequest_Process
            (rr.processRequest, mapper, serialisation, id);
        break;
    case RRType::Finish:
        j = VampJson::fromRpcRequest_Finish(rr.finishRequest, mapper, id);
        break;
    case RRType::NotValid:
        break;
    }

    cout << j.dump() << endl;
}

RequestOrResponse
readResponseJson(string &err)
{
    RequestOrResponse rr;
    rr.direction = RequestOrResponse::Response;

    string input;
    if (!getline(cin, input)) {
        // the EOF case, not actually an error
        rr.type = RRType::NotValid;
        return rr;
    }

    Json j = convertResponseJson(input, err);
    if (err != "") return {};

    rr.type = VampJson::getRequestResponseType(j, err);
    if (err != "") return {};

    rr.id = readJsonId(j);
    
    VampJson::BufferSerialisation serialisation =
        VampJson::BufferSerialisation::Array;

    rr.success = j["success"].bool_value();
    rr.errorText = j["errorText"].string_value();

    switch (rr.type) {

    case RRType::List:
        rr.listResponse = VampJson::toRpcResponse_List(j, err);
        break;
    case RRType::Load:
        rr.loadResponse = VampJson::toRpcResponse_Load(j, mapper, err);
        break;
    case RRType::Configure:
        rr.configurationResponse = VampJson::toRpcResponse_Configure(j, mapper, err);
        break;
    case RRType::Process: 
        rr.processResponse = VampJson::toRpcResponse_Process(j, mapper, serialisation, err);
        break;
    case RRType::Finish:
        rr.finishResponse = VampJson::toRpcResponse_Finish(j, mapper, serialisation, err);
        break;
    case RRType::NotValid:
        break;
    }

    return rr;
}

void
writeResponseJson(RequestOrResponse &rr, bool useBase64)
{
    Json j;

    VampJson::BufferSerialisation serialisation =
        (useBase64 ?
         VampJson::BufferSerialisation::Base64 :
         VampJson::BufferSerialisation::Array);

    Json id = writeJsonId(rr.id);

    if (!rr.success) {

        j = VampJson::fromError(rr.errorText, rr.type, id);

    } else {
    
        switch (rr.type) {

        case RRType::List:
            j = VampJson::fromRpcResponse_List(rr.listResponse, id);
            break;
        case RRType::Load:
            j = VampJson::fromRpcResponse_Load(rr.loadResponse, mapper, id);
            break;
        case RRType::Configure:
            j = VampJson::fromRpcResponse_Configure(rr.configurationResponse,
                                                    mapper, id);
            break;
        case RRType::Process:
            j = VampJson::fromRpcResponse_Process
                (rr.processResponse, mapper, serialisation, id);
            break;
        case RRType::Finish:
            j = VampJson::fromRpcResponse_Finish
                (rr.finishResponse, mapper, serialisation, id);
            break;
        case RRType::NotValid:
            break;
        }
    }
    
    cout << j.dump() << endl;
}

RequestOrResponse
readRequestCapnp(kj::BufferedInputStreamWrapper &buffered)
{
    RequestOrResponse rr;
    rr.direction = RequestOrResponse::Request;

    capnp::InputStreamMessageReader message(buffered);
    piper::RpcRequest::Reader reader = message.getRoot<piper::RpcRequest>();
    
    rr.type = VampnProto::getRequestResponseType(reader);
    rr.id = readCapnpId(reader);

    switch (rr.type) {

    case RRType::List:
        VampnProto::readRpcRequest_List(reader); // type check only
        break;
    case RRType::Load:
        VampnProto::readRpcRequest_Load(rr.loadRequest, reader);
        break;
    case RRType::Configure:
        VampnProto::readRpcRequest_Configure(rr.configurationRequest,
                                             reader, mapper);
        break;
    case RRType::Process:
        VampnProto::readRpcRequest_Process(rr.processRequest, reader, mapper);
        break;
    case RRType::Finish:
        VampnProto::readRpcRequest_Finish(rr.finishRequest, reader, mapper);
        break;
    case RRType::NotValid:
        break;
    }

    return rr;
}

void
writeRequestCapnp(RequestOrResponse &rr)
{
    capnp::MallocMessageBuilder message;
    piper::RpcRequest::Builder builder = message.initRoot<piper::RpcRequest>();

    buildCapnpId(builder, rr.id);
    
    switch (rr.type) {

    case RRType::List:
        VampnProto::buildRpcRequest_List(builder);
        break;
    case RRType::Load:
        VampnProto::buildRpcRequest_Load(builder, rr.loadRequest);
        break;
    case RRType::Configure:
        VampnProto::buildRpcRequest_Configure(builder,
                                              rr.configurationRequest, mapper);
        break;
    case RRType::Process:
        VampnProto::buildRpcRequest_Process(builder, rr.processRequest, mapper);
        break;
    case RRType::Finish:
        VampnProto::buildRpcRequest_Finish(builder, rr.finishRequest, mapper);
        break;
    case RRType::NotValid:
        break;
    }

    writeMessageToFd(1, message);
}

RequestOrResponse
readResponseCapnp(kj::BufferedInputStreamWrapper &buffered)
{
    RequestOrResponse rr;
    rr.direction = RequestOrResponse::Response;

    capnp::InputStreamMessageReader message(buffered);
    piper::RpcResponse::Reader reader = message.getRoot<piper::RpcResponse>();
    
    rr.type = VampnProto::getRequestResponseType(reader);
    rr.success = true;
    rr.errorText = "";
    rr.id = readCapnpId(reader);
    int errorCode = 0;

    switch (rr.type) {

    case RRType::List:
        VampnProto::readRpcResponse_List(rr.listResponse, reader);
        break;
    case RRType::Load:
        VampnProto::readRpcResponse_Load(rr.loadResponse, reader, mapper);
        break;
    case RRType::Configure:
        VampnProto::readRpcResponse_Configure(rr.configurationResponse,
                                              reader, mapper);
        break;
    case RRType::Process:
        VampnProto::readRpcResponse_Process(rr.processResponse, reader, mapper);
        break;
    case RRType::Finish:
        VampnProto::readRpcResponse_Finish(rr.finishResponse, reader, mapper);
        break;
    case RRType::NotValid:
        // error
        rr.success = false;
        VampnProto::readRpcResponse_Error(errorCode, rr.errorText, reader);
        break;
    }

    return rr;
}

void
writeResponseCapnp(RequestOrResponse &rr)
{
    capnp::MallocMessageBuilder message;
    piper::RpcResponse::Builder builder = message.initRoot<piper::RpcResponse>();

    buildCapnpId(builder, rr.id);

    if (!rr.success) {

        VampnProto::buildRpcResponse_Error(builder, rr.errorText, rr.type);

    } else {
        
        switch (rr.type) {

        case RRType::List:
            VampnProto::buildRpcResponse_List(builder, rr.listResponse);
            break;
        case RRType::Load:
            VampnProto::buildRpcResponse_Load(builder, rr.loadResponse, mapper);
            break;
        case RRType::Configure:
            VampnProto::buildRpcResponse_Configure(builder, rr.configurationResponse, mapper);
            break;
        case RRType::Process:
            VampnProto::buildRpcResponse_Process(builder, rr.processResponse, mapper);
            break;
        case RRType::Finish:
            VampnProto::buildRpcResponse_Finish(builder, rr.finishResponse, mapper);
            break;
        case RRType::NotValid:
            break;
        }
    }
    
    writeMessageToFd(1, message);
}

RequestOrResponse
readInputJson(RequestOrResponse::Direction direction, string &err)
{
    if (direction == RequestOrResponse::Request) {
        return readRequestJson(err);
    } else {
        return readResponseJson(err);
    }
}

RequestOrResponse
readInputCapnp(RequestOrResponse::Direction direction)
{
    static kj::FdInputStream stream(0); // stdin
    static kj::BufferedInputStreamWrapper buffered(stream);

    if (buffered.tryGetReadBuffer() == nullptr) {
        return {};
    }
    
    if (direction == RequestOrResponse::Request) {
        return readRequestCapnp(buffered);
    } else {
        return readResponseCapnp(buffered);
    }
}

RequestOrResponse
readInput(string format, RequestOrResponse::Direction direction)
{
    if (format == "json") {
        string err;
        auto result = readInputJson(direction, err);
        if (err != "") throw runtime_error(err);
        else return result;
    } else if (format == "capnp") {
        return readInputCapnp(direction);
    } else {
        throw runtime_error("unknown input format \"" + format + "\"");
    }
}

void
writeOutput(string format, RequestOrResponse &rr)
{
    if (format == "json") {
        if (rr.direction == RequestOrResponse::Request) {
            writeRequestJson(rr, false);
        } else {
            writeResponseJson(rr, false);
        }
    } else if (format == "json-b64") {
        if (rr.direction == RequestOrResponse::Request) {
            writeRequestJson(rr, true);
        } else {
            writeResponseJson(rr, true);
        }
    } else if (format == "capnp") {
        if (rr.direction == RequestOrResponse::Request) {
            writeRequestCapnp(rr);
        } else {
            writeResponseCapnp(rr);
        }
    } else {
        throw runtime_error("unknown output format \"" + format + "\"");
    }
}

int main(int argc, char **argv)
{
    if (argc < 2) {
        usage();
    }

    string informat = "json", outformat = "json";
    RequestOrResponse::Direction direction = RequestOrResponse::Request;
    bool haveDirection = false;
    
    for (int i = 1; i < argc; ++i) {

        string arg = argv[i];
        bool final = (i + 1 == argc);
        
        if (arg == "-i") {
            if (final) usage();
            else informat = argv[++i];

        } else if (arg == "-o") {
            if (final) usage();
            else outformat = argv[++i];

        } else if (arg == "request") {
            direction = RequestOrResponse::Request;
            haveDirection = true;

        } else if (arg == "response") {
            direction = RequestOrResponse::Response;
            haveDirection = true;
            
        } else {
            usage();
        }
    }

    if (informat == "" || outformat == "" || !haveDirection) {
        usage();
    }

    while (true) {

        try {

            RequestOrResponse rr = readInput(informat, direction);

            // NotValid without an exception indicates EOF:
            if (rr.type == RRType::NotValid) break;

            writeOutput(outformat, rr);
            
        } catch (std::exception &e) {

            cerr << "Error: " << e.what() << endl;
            exit(1);
        }
    }

    exit(0);
}