commands/orm.go - cordctl - Gitiles

 /*
  * Portions copyright 2019-present Open Networking Foundation
  * Original copyright 2019-present Ciena Corporation
  *
  * 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.
  */
 package commands

 import (
 	"context"
 	"errors"
 	"fmt"
 	"github.com/fullstorydev/grpcurl"
 	"github.com/golang/protobuf/proto"
 	"github.com/golang/protobuf/protoc-gen-go/descriptor"
 	"github.com/jhump/protoreflect/desc"
 	"github.com/jhump/protoreflect/dynamic"
 	"google.golang.org/grpc"
 	"io"
 	"strconv"
 	"strings"
 	"time"
 )

 // Flags for calling the *WithRetry methods
 const (
 	GM_QUIET         = 1
 	GM_UNTIL_FOUND   = 2
 	GM_UNTIL_ENACTED = 4
 	GM_UNTIL_STATUS  = 8
 )

 // Valid choices for FilterModels `Kind` argument
 const (
 	FILTER_DEFAULT    = "DEFAULT"
 	FILTER_ALL        = "ALL"
 	FILTER_DIRTY      = "SYNCHRONIZER_DIRTY_OBJECTS"
 	FILTER_DELETED    = "SYNCHRONIZER_DELETED_OBJECTS"
 	FILTER_DIRTYPOL   = "SYNCHRONIZER_DIRTY_POLICIES"
 	FILTER_DELETEDPOL = "SYNCHRONIZER_DELETED_POLICIES"
 )

 type QueryEventHandler struct {
 	RpcEventHandler
 	Elements map[string]string
 	Model    *desc.MessageDescriptor
 	Kind     string
 	EOF      bool
 }

 // Separate the operator from the query value.
 // For example,
 //    "==foo"  --> "EQUAL", "foo"
 func DecodeOperator(query string) (string, string, bool, error) {
 	if strings.HasPrefix(query, "!=") {
 		return strings.TrimSpace(query[2:]), "EQUAL", true, nil
 	} else if strings.HasPrefix(query, "==") {
 		return "", "", false, errors.New("Operator == is now allowed. Suggest using = instead.")
 	} else if strings.HasPrefix(query, "=") {
 		return strings.TrimSpace(query[1:]), "EQUAL", false, nil
 	} else if strings.HasPrefix(query, ">=") {
 		return strings.TrimSpace(query[2:]), "GREATER_THAN_OR_EQUAL", false, nil
 	} else if strings.HasPrefix(query, ">") {
 		return strings.TrimSpace(query[1:]), "GREATER_THAN", false, nil
 	} else if strings.HasPrefix(query, "<=") {
 		return strings.TrimSpace(query[2:]), "LESS_THAN_OR_EQUAL", false, nil
 	} else if strings.HasPrefix(query, "<") {
 		return strings.TrimSpace(query[1:]), "LESS_THAN", false, nil
 	} else {
 		return strings.TrimSpace(query), "EQUAL", false, nil
 	}
 }

 // Generate the parameters for Query messages.
 func (h *QueryEventHandler) GetParams(msg proto.Message) error {
 	dmsg, err := dynamic.AsDynamicMessage(msg)
 	if err != nil {
 		return err
 	}

 	//fmt.Printf("MessageName: %s\n", dmsg.XXX_MessageName())

 	if h.EOF {
 		return io.EOF
 	}

 	// Get the MessageType for the `elements` field
 	md := dmsg.GetMessageDescriptor()
 	elements_fld := md.FindFieldByName("elements")
 	elements_mt := elements_fld.GetMessageType()

 	for field_name, element := range h.Elements {
 		value, operator, invert, err := DecodeOperator(element)
 		if err != nil {
 			return err
 		}

 		nm := dynamic.NewMessage(elements_mt)

 		field_descriptor := h.Model.FindFieldByName(field_name)
 		if field_descriptor == nil {
 			return fmt.Errorf("Field %s does not exist", field_name)
 		}

 		field_type := field_descriptor.GetType()
 		switch field_type {
 		case descriptor.FieldDescriptorProto_TYPE_INT32:
 			var i int64
 			i, err = strconv.ParseInt(value, 10, 32)
 			nm.SetFieldByName("iValue", int32(i))
 		case descriptor.FieldDescriptorProto_TYPE_UINT32:
 			var i int64
 			i, err = strconv.ParseInt(value, 10, 32)
 			nm.SetFieldByName("iValue", uint32(i))
 		case descriptor.FieldDescriptorProto_TYPE_FLOAT:
 			err = errors.New("Floating point filters are unsupported")
 		case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
 			err = errors.New("Floating point filters are unsupported")
 		default:
 			nm.SetFieldByName("sValue", value)
 			err = nil
 		}

 		if err != nil {
 			return err
 		}

 		nm.SetFieldByName("name", field_name)
 		nm.SetFieldByName("invert", invert)
 		SetEnumValue(nm, "operator", operator)
 		dmsg.AddRepeatedFieldByName("elements", nm)
 	}

 	SetEnumValue(dmsg, "kind", h.Kind)

 	h.EOF = true

 	return nil
 }

 // Take a string list of queries and turns it into a map of queries
 func QueryStringsToMap(query_args []string, allow_inequality bool) (map[string]string, error) {
 	queries := make(map[string]string)
 	for _, query_str := range query_args {
 		query_str := strings.TrimSpace(query_str)
 		operator_pos := -1
 		for i, ch := range query_str {
 			if allow_inequality {
 				if (ch == '!') || (ch == '=') || (ch == '>') || (ch == '<') {
 					operator_pos = i
 					break
 				}
 			} else {
 				if ch == '=' {
 					operator_pos = i
 					break
 				}
 			}
 		}
 		if operator_pos == -1 {
 			return nil, fmt.Errorf("Illegal operator/value string %s", query_str)
 		}
 		queries[strings.TrimSpace(query_str[:operator_pos])] = query_str[operator_pos:]
 	}
 	return queries, nil
 }

 // Take a string of comma-separated queries and turn it into a map of queries
 func CommaSeparatedQueryToMap(query_str string, allow_inequality bool) (map[string]string, error) {
 	if query_str == "" {
 		return nil, nil
 	}

 	query_strings := strings.Split(query_str, ",")
 	return QueryStringsToMap(query_strings, allow_inequality)
 }

 // Convert a string into the appropriate gRPC type for a given field
 func TypeConvert(source grpcurl.DescriptorSource, modelName string, field_name string, v string) (interface{}, error) {
 	model_descriptor, err := source.FindSymbol("xos." + modelName)
 	if err != nil {
 		return nil, err
 	}
 	model_md, ok := model_descriptor.(*desc.MessageDescriptor)
 	if !ok {
 		return nil, fmt.Errorf("Failed to convert model %s to a messagedescriptor", modelName)
 	}
 	field_descriptor := model_md.FindFieldByName(field_name)
 	if field_descriptor == nil {
 		return nil, fmt.Errorf("Field %s does not exist in model %s", field_name, modelName)
 	}
 	field_type := field_descriptor.GetType()

 	var result interface{}

 	switch field_type {
 	case descriptor.FieldDescriptorProto_TYPE_INT32:
 		var i int64
 		i, err = strconv.ParseInt(v, 10, 32)
 		result = int32(i)
 	case descriptor.FieldDescriptorProto_TYPE_UINT32:
 		var i int64
 		i, err = strconv.ParseInt(v, 10, 32)
 		result = uint32(i)
 	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
 		var f float64
 		f, err = strconv.ParseFloat(v, 32)
 		result = float32(f)
 	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
 		var f float64
 		f, err = strconv.ParseFloat(v, 64)
 		result = f
 	default:
 		result = v
 		err = nil
 	}

 	return result, err
 }

 // Return a list of all available model names
 func GetModelNames(source grpcurl.DescriptorSource) (map[string]bool, error) {
 	models := make(map[string]bool)
 	methods, err := grpcurl.ListMethods(source, "xos.xos")

 	if err != nil {
 		return nil, err
 	}

 	for _, method := range methods {
 		if strings.HasPrefix(method, "xos.xos.Get") {
 			models[method[11:]] = true
 		}
 	}

 	return models, nil
 }

 // Check to see if a model name is valid
 func CheckModelName(source grpcurl.DescriptorSource, name string) error {
 	models, err := GetModelNames(source)
 	if err != nil {
 		return err
 	}
 	_, present := models[name]
 	if !present {
 		return errors.New("Model " + name + " does not exist. Use `cordctl models available` to get a list of available models")
 	}
 	return nil
 }

 // Create a model in XOS given a map of fields
 func CreateModel(conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, fields map[string]interface{}) error {
 	ctx, cancel := context.WithTimeout(context.Background(), GlobalConfig.Grpc.Timeout)
 	defer cancel()

 	headers := GenerateHeaders()

 	h := &RpcEventHandler{
 		Fields: map[string]map[string]interface{}{"xos." + modelName: fields},
 	}
 	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Create"+modelName, headers, h, h.GetParams)
 	if err != nil {
 		return err
 	} else if h.Status != nil && h.Status.Err() != nil {
 		return h.Status.Err()
 	}

 	resp, err := dynamic.AsDynamicMessage(h.Response)
 	if err != nil {
 		return err
 	}

 	fields["id"] = resp.GetFieldByName("id").(int32)

 	if resp.HasFieldName("uuid") {
 		fields["uuid"] = resp.GetFieldByName("uuid").(string)
 	}

 	return nil
 }

 // Update a model in XOS given a map of fields
 func UpdateModel(conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, fields map[string]interface{}) error {
 	ctx, cancel := context.WithTimeout(context.Background(), GlobalConfig.Grpc.Timeout)
 	defer cancel()

 	headers := GenerateHeaders()

 	h := &RpcEventHandler{
 		Fields: map[string]map[string]interface{}{"xos." + modelName: fields},
 	}
 	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Update"+modelName, headers, h, h.GetParams)
 	if err != nil {
 		return err
 	} else if h.Status != nil && h.Status.Err() != nil {
 		return h.Status.Err()
 	}

 	resp, err := dynamic.AsDynamicMessage(h.Response)
 	if err != nil {
 		return err
 	}

 	// TODO: Do we need to do anything with the response?
 	_ = resp

 	return nil
 }

 // Get a model from XOS given its ID
 func GetModel(ctx context.Context, conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, id int32) (*dynamic.Message, error) {
 	ctx, cancel := context.WithTimeout(ctx, GlobalConfig.Grpc.Timeout)
 	defer cancel()

 	headers := GenerateHeaders()

 	h := &RpcEventHandler{
 		Fields: map[string]map[string]interface{}{"xos.ID": map[string]interface{}{"id": id}},
 	}
 	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Get"+modelName, headers, h, h.GetParams)
 	if err != nil {
 		return nil, err
 	}

 	if h.Status != nil && h.Status.Err() != nil {
 		return nil, h.Status.Err()
 	}

 	d, err := dynamic.AsDynamicMessage(h.Response)
 	if err != nil {
 		return nil, err
 	}

 	return d, nil
 }

 // Get a model, but retry under a variety of circumstances
 func GetModelWithRetry(ctx context.Context, conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, id int32, flags uint32) (*grpc.ClientConn, *dynamic.Message, error) {
 	quiet := (flags & GM_QUIET) != 0
 	until_found := (flags & GM_UNTIL_FOUND) != 0
 	until_enacted := (flags & GM_UNTIL_ENACTED) != 0
 	until_status := (flags & GM_UNTIL_STATUS) != 0

 	for {
 		var err error

 		if conn == nil {
 			conn, err = NewConnection()
 			if err != nil {
 				return nil, nil, err
 			}
 		}

 		model, err := GetModel(ctx, conn, descriptor, modelName, id)
 		if err != nil {
 			if strings.Contains(err.Error(), "rpc error: code = Unavailable") ||
 				strings.Contains(err.Error(), "rpc error: code = Internal desc = stream terminated by RST_STREAM") {
 				if !quiet {
 					fmt.Print(".")
 				}
 				select {
 				case <-time.After(100 * time.Millisecond):
 				case <-ctx.Done():
 					return nil, nil, ctx.Err()
 				}
 				conn.Close()
 				conn = nil
 				continue
 			}

 			if until_found && strings.Contains(err.Error(), "rpc error: code = NotFound") {
 				if !quiet {
 					fmt.Print("x")
 				}
 				select {
 				case <-time.After(100 * time.Millisecond):
 				case <-ctx.Done():
 					return nil, nil, ctx.Err()
 				}
 				continue
 			}
 			return nil, nil, err
 		}

 		if until_enacted && !IsEnacted(model) {
 			if !quiet {
 				fmt.Print("o")
 			}
 			select {
 			case <-time.After(100 * time.Millisecond):
 			case <-ctx.Done():
 				return nil, nil, ctx.Err()
 			}
 			continue
 		}

 		if until_status && model.GetFieldByName("status") == nil {
 			if !quiet {
 				fmt.Print("O")
 			}
 			select {
 			case <-time.After(100 * time.Millisecond):
 			case <-ctx.Done():
 				return nil, nil, ctx.Err()
 			}
 			continue
 		}

 		return conn, model, nil
 	}
 }

 func ItemsToDynamicMessageList(items interface{}) []*dynamic.Message {
 	result := make([]*dynamic.Message, len(items.([]interface{})))
 	for i, item := range items.([]interface{}) {
 		result[i] = item.(*dynamic.Message)
 	}
 	return result
 }

 // List all objects of a given model
 func ListModels(ctx context.Context, conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string) ([]*dynamic.Message, error) {
 	ctx, cancel := context.WithTimeout(ctx, GlobalConfig.Grpc.Timeout)
 	defer cancel()

 	headers := GenerateHeaders()

 	h := &RpcEventHandler{}
 	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.List"+modelName, headers, h, h.GetParams)
 	if err != nil {
 		return nil, err
 	}

 	if h.Status != nil && h.Status.Err() != nil {
 		return nil, h.Status.Err()
 	}

 	d, err := dynamic.AsDynamicMessage(h.Response)
 	if err != nil {
 		return nil, err
 	}

 	items, err := d.TryGetFieldByName("items")
 	if err != nil {
 		return nil, err
 	}

 	return ItemsToDynamicMessageList(items), nil
 }

 // Filter models based on field values
 //   queries is a map of <field_name> to <operator><query>
 //   For example,
 //     map[string]string{"name": "==mysite"}
 func FilterModels(ctx context.Context, conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, kind string, queries map[string]string) ([]*dynamic.Message, error) {
 	ctx, cancel := context.WithTimeout(ctx, GlobalConfig.Grpc.Timeout)
 	defer cancel()

 	headers := GenerateHeaders()

 	model_descriptor, err := descriptor.FindSymbol("xos." + modelName)
 	if err != nil {
 		return nil, err
 	}
 	model_md, ok := model_descriptor.(*desc.MessageDescriptor)
 	if !ok {
 		return nil, errors.New("Failed to convert model to a messagedescriptor")
 	}

 	h := &QueryEventHandler{
 		RpcEventHandler: RpcEventHandler{
 			Fields: map[string]map[string]interface{}{"xos.Query": map[string]interface{}{"kind": 0}},
 		},
 		Elements: queries,
 		Model:    model_md,
 		Kind:     kind,
 	}
 	err = grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Filter"+modelName, headers, h, h.GetParams)
 	if err != nil {
 		return nil, err
 	}

 	if h.Status != nil && h.Status.Err() != nil {
 		return nil, h.Status.Err()
 	}

 	d, err := dynamic.AsDynamicMessage(h.Response)
 	if err != nil {
 		return nil, err
 	}

 	items, err := d.TryGetFieldByName("items")
 	if err != nil {
 		return nil, err
 	}

 	return ItemsToDynamicMessageList(items), nil
 }

 // Call ListModels or FilterModels as appropriate
 func ListOrFilterModels(ctx context.Context, conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, kind string, queries map[string]string) ([]*dynamic.Message, error) {
 	if (len(queries) == 0) && (kind == FILTER_DEFAULT) {
 		return ListModels(ctx, conn, descriptor, modelName)
 	} else {
 		return FilterModels(ctx, conn, descriptor, modelName, kind, queries)
 	}
 }

 // Get a model from XOS given a fieldName/fieldValue
 func FindModel(ctx context.Context, conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, queries map[string]string) (*dynamic.Message, error) {
 	models, err := FilterModels(ctx, conn, descriptor, modelName, FILTER_DEFAULT, queries)
 	if err != nil {
 		return nil, err
 	}

 	if len(models) == 0 {
 		return nil, errors.New("rpc error: code = NotFound")
 	}

 	return models[0], nil
 }

 // Find a model, but retry under a variety of circumstances
 func FindModelWithRetry(ctx context.Context, conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, queries map[string]string, flags uint32) (*grpc.ClientConn, *dynamic.Message, error) {
 	quiet := (flags & GM_QUIET) != 0
 	until_found := (flags & GM_UNTIL_FOUND) != 0
 	until_enacted := (flags & GM_UNTIL_ENACTED) != 0
 	until_status := (flags & GM_UNTIL_STATUS) != 0

 	for {
 		var err error

 		if conn == nil {
 			conn, err = NewConnection()
 			if err != nil {
 				return nil, nil, err
 			}
 		}

 		model, err := FindModel(ctx, conn, descriptor, modelName, queries)
 		if err != nil {
 			if strings.Contains(err.Error(), "rpc error: code = Unavailable") ||
 				strings.Contains(err.Error(), "rpc error: code = Internal desc = stream terminated by RST_STREAM") {
 				if !quiet {
 					fmt.Print(".")
 				}
 				select {
 				case <-time.After(100 * time.Millisecond):
 				case <-ctx.Done():
 					return nil, nil, ctx.Err()
 				}
 				conn.Close()
 				conn = nil
 				continue
 			}

 			if until_found && strings.Contains(err.Error(), "rpc error: code = NotFound") {
 				if !quiet {
 					fmt.Print("x")
 				}
 				select {
 				case <-time.After(100 * time.Millisecond):
 				case <-ctx.Done():
 					return nil, nil, ctx.Err()
 				}
 				continue
 			}
 			return nil, nil, err
 		}

 		if until_enacted && !IsEnacted(model) {
 			if !quiet {
 				fmt.Print("o")
 			}
 			select {
 			case <-time.After(100 * time.Millisecond):
 			case <-ctx.Done():
 				return nil, nil, ctx.Err()
 			}
 			continue
 		}

 		if until_status && model.GetFieldByName("status") == nil {
 			if !quiet {
 				fmt.Print("O")
 			}
 			select {
 			case <-time.After(100 * time.Millisecond):
 			case <-ctx.Done():
 				return nil, nil, ctx.Err()
 			}
 			continue
 		}

 		return conn, model, nil
 	}
 }

 // Get a model from XOS given its ID
 func DeleteModel(conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, id int32) error {
 	ctx, cancel := context.WithTimeout(context.Background(), GlobalConfig.Grpc.Timeout)
 	defer cancel()

 	headers := GenerateHeaders()

 	h := &RpcEventHandler{
 		Fields: map[string]map[string]interface{}{"xos.ID": map[string]interface{}{"id": id}},
 	}
 	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Delete"+modelName, headers, h, h.GetParams)
 	if err != nil {
 		return err
 	}

 	if h.Status != nil && h.Status.Err() != nil {
 		return h.Status.Err()
 	}

 	_, err = dynamic.AsDynamicMessage(h.Response)
 	if err != nil {
 		return err
 	}

 	return nil
 }

 // Takes a *dynamic.Message and turns it into a map of fields to interfaces
 //    TODO: Might be more useful to convert the values to strings and ints
 func MessageToMap(d *dynamic.Message) map[string]interface{} {
 	fields := make(map[string]interface{})
 	for _, field_desc := range d.GetKnownFields() {
 		field_name := field_desc.GetName()
 		fields[field_name] = d.GetFieldByName(field_name)
 	}
 	return fields
 }

 // Returns True if a message has been enacted
 func IsEnacted(d *dynamic.Message) bool {
 	enacted := d.GetFieldByName("enacted").(float64)
 	updated := d.GetFieldByName("updated").(float64)

 	return (enacted >= updated)
 }
	/*
	* Portions copyright 2019-present Open Networking Foundation
	* Original copyright 2019-present Ciena Corporation
	*
	* 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.
	*/
	package commands

	import (
	"context"
	"errors"
	"fmt"
	"github.com/fullstorydev/grpcurl"
	"github.com/golang/protobuf/proto"
	"github.com/golang/protobuf/protoc-gen-go/descriptor"
	"github.com/jhump/protoreflect/desc"
	"github.com/jhump/protoreflect/dynamic"
	"google.golang.org/grpc"
	"io"
	"strconv"
	"strings"
	"time"
	)

	// Flags for calling the *WithRetry methods
	const (
	GM_QUIET = 1
	GM_UNTIL_FOUND = 2
	GM_UNTIL_ENACTED = 4
	GM_UNTIL_STATUS = 8
	)

	// Valid choices for FilterModels `Kind` argument
	const (
	FILTER_DEFAULT = "DEFAULT"
	FILTER_ALL = "ALL"
	FILTER_DIRTY = "SYNCHRONIZER_DIRTY_OBJECTS"
	FILTER_DELETED = "SYNCHRONIZER_DELETED_OBJECTS"
	FILTER_DIRTYPOL = "SYNCHRONIZER_DIRTY_POLICIES"
	FILTER_DELETEDPOL = "SYNCHRONIZER_DELETED_POLICIES"
	)

	type QueryEventHandler struct {
	RpcEventHandler
	Elements map[string]string
	Model *desc.MessageDescriptor
	Kind string
	EOF bool
	}

	// Separate the operator from the query value.
	// For example,
	// "==foo" --> "EQUAL", "foo"
	func DecodeOperator(query string) (string, string, bool, error) {
	if strings.HasPrefix(query, "!=") {
	return strings.TrimSpace(query[2:]), "EQUAL", true, nil
	} else if strings.HasPrefix(query, "==") {
	return "", "", false, errors.New("Operator == is now allowed. Suggest using = instead.")
	} else if strings.HasPrefix(query, "=") {
	return strings.TrimSpace(query[1:]), "EQUAL", false, nil
	} else if strings.HasPrefix(query, ">=") {
	return strings.TrimSpace(query[2:]), "GREATER_THAN_OR_EQUAL", false, nil
	} else if strings.HasPrefix(query, ">") {
	return strings.TrimSpace(query[1:]), "GREATER_THAN", false, nil
	} else if strings.HasPrefix(query, "<=") {
	return strings.TrimSpace(query[2:]), "LESS_THAN_OR_EQUAL", false, nil
	} else if strings.HasPrefix(query, "<") {
	return strings.TrimSpace(query[1:]), "LESS_THAN", false, nil
	} else {
	return strings.TrimSpace(query), "EQUAL", false, nil
	}
	}

	// Generate the parameters for Query messages.
	func (h *QueryEventHandler) GetParams(msg proto.Message) error {
	dmsg, err := dynamic.AsDynamicMessage(msg)
	if err != nil {
	return err
	}

	//fmt.Printf("MessageName: %s\n", dmsg.XXX_MessageName())

	if h.EOF {
	return io.EOF
	}

	// Get the MessageType for the `elements` field
	md := dmsg.GetMessageDescriptor()
	elements_fld := md.FindFieldByName("elements")
	elements_mt := elements_fld.GetMessageType()

	for field_name, element := range h.Elements {
	value, operator, invert, err := DecodeOperator(element)
	if err != nil {
	return err
	}

	nm := dynamic.NewMessage(elements_mt)

	field_descriptor := h.Model.FindFieldByName(field_name)
	if field_descriptor == nil {
	return fmt.Errorf("Field %s does not exist", field_name)
	}

	field_type := field_descriptor.GetType()
	switch field_type {
	case descriptor.FieldDescriptorProto_TYPE_INT32:
	var i int64
	i, err = strconv.ParseInt(value, 10, 32)
	nm.SetFieldByName("iValue", int32(i))
	case descriptor.FieldDescriptorProto_TYPE_UINT32:
	var i int64
	i, err = strconv.ParseInt(value, 10, 32)
	nm.SetFieldByName("iValue", uint32(i))
	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
	err = errors.New("Floating point filters are unsupported")
	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
	err = errors.New("Floating point filters are unsupported")
	default:
	nm.SetFieldByName("sValue", value)
	err = nil
	}

	if err != nil {
	return err
	}

	nm.SetFieldByName("name", field_name)
	nm.SetFieldByName("invert", invert)
	SetEnumValue(nm, "operator", operator)
	dmsg.AddRepeatedFieldByName("elements", nm)
	}

	SetEnumValue(dmsg, "kind", h.Kind)

	h.EOF = true

	return nil
	}

	// Take a string list of queries and turns it into a map of queries
	func QueryStringsToMap(query_args []string, allow_inequality bool) (map[string]string, error) {
	queries := make(map[string]string)
	for _, query_str := range query_args {
	query_str := strings.TrimSpace(query_str)
	operator_pos := -1
	for i, ch := range query_str {
	if allow_inequality {
	if (ch == '!') \|\| (ch == '=') \|\| (ch == '>') \|\| (ch == '<') {
	operator_pos = i
	break
	}
	} else {
	if ch == '=' {
	operator_pos = i
	break
	}
	}
	}
	if operator_pos == -1 {
	return nil, fmt.Errorf("Illegal operator/value string %s", query_str)
	}
	queries[strings.TrimSpace(query_str[:operator_pos])] = query_str[operator_pos:]
	}
	return queries, nil
	}

	// Take a string of comma-separated queries and turn it into a map of queries
	func CommaSeparatedQueryToMap(query_str string, allow_inequality bool) (map[string]string, error) {
	if query_str == "" {
	return nil, nil
	}

	query_strings := strings.Split(query_str, ",")
	return QueryStringsToMap(query_strings, allow_inequality)
	}

	// Convert a string into the appropriate gRPC type for a given field
	func TypeConvert(source grpcurl.DescriptorSource, modelName string, field_name string, v string) (interface{}, error) {
	model_descriptor, err := source.FindSymbol("xos." + modelName)
	if err != nil {
	return nil, err
	}
	model_md, ok := model_descriptor.(*desc.MessageDescriptor)
	if !ok {
	return nil, fmt.Errorf("Failed to convert model %s to a messagedescriptor", modelName)
	}
	field_descriptor := model_md.FindFieldByName(field_name)
	if field_descriptor == nil {
	return nil, fmt.Errorf("Field %s does not exist in model %s", field_name, modelName)
	}
	field_type := field_descriptor.GetType()

	var result interface{}

	switch field_type {
	case descriptor.FieldDescriptorProto_TYPE_INT32:
	var i int64
	i, err = strconv.ParseInt(v, 10, 32)
	result = int32(i)
	case descriptor.FieldDescriptorProto_TYPE_UINT32:
	var i int64
	i, err = strconv.ParseInt(v, 10, 32)
	result = uint32(i)
	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
	var f float64
	f, err = strconv.ParseFloat(v, 32)
	result = float32(f)
	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
	var f float64
	f, err = strconv.ParseFloat(v, 64)
	result = f
	default:
	result = v
	err = nil
	}

	return result, err
	}

	// Return a list of all available model names
	func GetModelNames(source grpcurl.DescriptorSource) (map[string]bool, error) {
	models := make(map[string]bool)
	methods, err := grpcurl.ListMethods(source, "xos.xos")

	if err != nil {
	return nil, err
	}

	for _, method := range methods {
	if strings.HasPrefix(method, "xos.xos.Get") {
	models[method[11:]] = true
	}
	}

	return models, nil
	}

	// Check to see if a model name is valid
	func CheckModelName(source grpcurl.DescriptorSource, name string) error {
	models, err := GetModelNames(source)
	if err != nil {
	return err
	}
	_, present := models[name]
	if !present {
	return errors.New("Model " + name + " does not exist. Use `cordctl models available` to get a list of available models")
	}
	return nil
	}

	// Create a model in XOS given a map of fields
	func CreateModel(conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, fields map[string]interface{}) error {
	ctx, cancel := context.WithTimeout(context.Background(), GlobalConfig.Grpc.Timeout)
	defer cancel()

	headers := GenerateHeaders()

	h := &RpcEventHandler{
	Fields: map[string]map[string]interface{}{"xos." + modelName: fields},
	}
	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Create"+modelName, headers, h, h.GetParams)
	if err != nil {
	return err
	} else if h.Status != nil && h.Status.Err() != nil {
	return h.Status.Err()
	}

	resp, err := dynamic.AsDynamicMessage(h.Response)
	if err != nil {
	return err
	}

	fields["id"] = resp.GetFieldByName("id").(int32)

	if resp.HasFieldName("uuid") {
	fields["uuid"] = resp.GetFieldByName("uuid").(string)
	}

	return nil
	}

	// Update a model in XOS given a map of fields
	func UpdateModel(conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, fields map[string]interface{}) error {
	ctx, cancel := context.WithTimeout(context.Background(), GlobalConfig.Grpc.Timeout)
	defer cancel()

	headers := GenerateHeaders()

	h := &RpcEventHandler{
	Fields: map[string]map[string]interface{}{"xos." + modelName: fields},
	}
	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Update"+modelName, headers, h, h.GetParams)
	if err != nil {
	return err
	} else if h.Status != nil && h.Status.Err() != nil {
	return h.Status.Err()
	}

	resp, err := dynamic.AsDynamicMessage(h.Response)
	if err != nil {
	return err
	}

	// TODO: Do we need to do anything with the response?
	_ = resp

	return nil
	}

	// Get a model from XOS given its ID
	func GetModel(ctx context.Context, conn grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, id int32) (dynamic.Message, error) {
	ctx, cancel := context.WithTimeout(ctx, GlobalConfig.Grpc.Timeout)
	defer cancel()

	headers := GenerateHeaders()

	h := &RpcEventHandler{
	Fields: map[string]map[string]interface{}{"xos.ID": map[string]interface{}{"id": id}},
	}
	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Get"+modelName, headers, h, h.GetParams)
	if err != nil {
	return nil, err
	}

	if h.Status != nil && h.Status.Err() != nil {
	return nil, h.Status.Err()
	}

	d, err := dynamic.AsDynamicMessage(h.Response)
	if err != nil {
	return nil, err
	}

	return d, nil
	}

	// Get a model, but retry under a variety of circumstances
	func GetModelWithRetry(ctx context.Context, conn grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, id int32, flags uint32) (grpc.ClientConn, *dynamic.Message, error) {
	quiet := (flags & GM_QUIET) != 0
	until_found := (flags & GM_UNTIL_FOUND) != 0
	until_enacted := (flags & GM_UNTIL_ENACTED) != 0
	until_status := (flags & GM_UNTIL_STATUS) != 0

	for {
	var err error

	if conn == nil {
	conn, err = NewConnection()
	if err != nil {
	return nil, nil, err
	}
	}

	model, err := GetModel(ctx, conn, descriptor, modelName, id)
	if err != nil {
	if strings.Contains(err.Error(), "rpc error: code = Unavailable") \|\|
	strings.Contains(err.Error(), "rpc error: code = Internal desc = stream terminated by RST_STREAM") {
	if !quiet {
	fmt.Print(".")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	conn.Close()
	conn = nil
	continue
	}

	if until_found && strings.Contains(err.Error(), "rpc error: code = NotFound") {
	if !quiet {
	fmt.Print("x")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	continue
	}
	return nil, nil, err
	}

	if until_enacted && !IsEnacted(model) {
	if !quiet {
	fmt.Print("o")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	continue
	}

	if until_status && model.GetFieldByName("status") == nil {
	if !quiet {
	fmt.Print("O")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	continue
	}

	return conn, model, nil
	}
	}

	func ItemsToDynamicMessageList(items interface{}) []*dynamic.Message {
	result := make([]*dynamic.Message, len(items.([]interface{})))
	for i, item := range items.([]interface{}) {
	result[i] = item.(*dynamic.Message)
	}
	return result
	}

	// List all objects of a given model
	func ListModels(ctx context.Context, conn grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string) ([]dynamic.Message, error) {
	ctx, cancel := context.WithTimeout(ctx, GlobalConfig.Grpc.Timeout)
	defer cancel()

	headers := GenerateHeaders()

	h := &RpcEventHandler{}
	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.List"+modelName, headers, h, h.GetParams)
	if err != nil {
	return nil, err
	}

	if h.Status != nil && h.Status.Err() != nil {
	return nil, h.Status.Err()
	}

	d, err := dynamic.AsDynamicMessage(h.Response)
	if err != nil {
	return nil, err
	}

	items, err := d.TryGetFieldByName("items")
	if err != nil {
	return nil, err
	}

	return ItemsToDynamicMessageList(items), nil
	}

	// Filter models based on field values
	// queries is a map of <field_name> to <operator><query>
	// For example,
	// map[string]string{"name": "==mysite"}
	func FilterModels(ctx context.Context, conn grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, kind string, queries map[string]string) ([]dynamic.Message, error) {
	ctx, cancel := context.WithTimeout(ctx, GlobalConfig.Grpc.Timeout)
	defer cancel()

	headers := GenerateHeaders()

	model_descriptor, err := descriptor.FindSymbol("xos." + modelName)
	if err != nil {
	return nil, err
	}
	model_md, ok := model_descriptor.(*desc.MessageDescriptor)
	if !ok {
	return nil, errors.New("Failed to convert model to a messagedescriptor")
	}

	h := &QueryEventHandler{
	RpcEventHandler: RpcEventHandler{
	Fields: map[string]map[string]interface{}{"xos.Query": map[string]interface{}{"kind": 0}},
	},
	Elements: queries,
	Model: model_md,
	Kind: kind,
	}
	err = grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Filter"+modelName, headers, h, h.GetParams)
	if err != nil {
	return nil, err
	}

	if h.Status != nil && h.Status.Err() != nil {
	return nil, h.Status.Err()
	}

	d, err := dynamic.AsDynamicMessage(h.Response)
	if err != nil {
	return nil, err
	}

	items, err := d.TryGetFieldByName("items")
	if err != nil {
	return nil, err
	}

	return ItemsToDynamicMessageList(items), nil
	}

	// Call ListModels or FilterModels as appropriate
	func ListOrFilterModels(ctx context.Context, conn grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, kind string, queries map[string]string) ([]dynamic.Message, error) {
	if (len(queries) == 0) && (kind == FILTER_DEFAULT) {
	return ListModels(ctx, conn, descriptor, modelName)
	} else {
	return FilterModels(ctx, conn, descriptor, modelName, kind, queries)
	}
	}

	// Get a model from XOS given a fieldName/fieldValue
	func FindModel(ctx context.Context, conn grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, queries map[string]string) (dynamic.Message, error) {
	models, err := FilterModels(ctx, conn, descriptor, modelName, FILTER_DEFAULT, queries)
	if err != nil {
	return nil, err
	}

	if len(models) == 0 {
	return nil, errors.New("rpc error: code = NotFound")
	}

	return models[0], nil
	}

	// Find a model, but retry under a variety of circumstances
	func FindModelWithRetry(ctx context.Context, conn grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, queries map[string]string, flags uint32) (grpc.ClientConn, *dynamic.Message, error) {
	quiet := (flags & GM_QUIET) != 0
	until_found := (flags & GM_UNTIL_FOUND) != 0
	until_enacted := (flags & GM_UNTIL_ENACTED) != 0
	until_status := (flags & GM_UNTIL_STATUS) != 0

	for {
	var err error

	if conn == nil {
	conn, err = NewConnection()
	if err != nil {
	return nil, nil, err
	}
	}

	model, err := FindModel(ctx, conn, descriptor, modelName, queries)
	if err != nil {
	if strings.Contains(err.Error(), "rpc error: code = Unavailable") \|\|
	strings.Contains(err.Error(), "rpc error: code = Internal desc = stream terminated by RST_STREAM") {
	if !quiet {
	fmt.Print(".")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	conn.Close()
	conn = nil
	continue
	}

	if until_found && strings.Contains(err.Error(), "rpc error: code = NotFound") {
	if !quiet {
	fmt.Print("x")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	continue
	}
	return nil, nil, err
	}

	if until_enacted && !IsEnacted(model) {
	if !quiet {
	fmt.Print("o")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	continue
	}

	if until_status && model.GetFieldByName("status") == nil {
	if !quiet {
	fmt.Print("O")
	}
	select {
	case <-time.After(100 * time.Millisecond):
	case <-ctx.Done():
	return nil, nil, ctx.Err()
	}
	continue
	}

	return conn, model, nil
	}
	}

	// Get a model from XOS given its ID
	func DeleteModel(conn *grpc.ClientConn, descriptor grpcurl.DescriptorSource, modelName string, id int32) error {
	ctx, cancel := context.WithTimeout(context.Background(), GlobalConfig.Grpc.Timeout)
	defer cancel()

	headers := GenerateHeaders()

	h := &RpcEventHandler{
	Fields: map[string]map[string]interface{}{"xos.ID": map[string]interface{}{"id": id}},
	}
	err := grpcurl.InvokeRPC(ctx, descriptor, conn, "xos.xos.Delete"+modelName, headers, h, h.GetParams)
	if err != nil {
	return err
	}

	if h.Status != nil && h.Status.Err() != nil {
	return h.Status.Err()
	}

	_, err = dynamic.AsDynamicMessage(h.Response)
	if err != nil {
	return err
	}

	return nil
	}

	// Takes a *dynamic.Message and turns it into a map of fields to interfaces
	// TODO: Might be more useful to convert the values to strings and ints
	func MessageToMap(d *dynamic.Message) map[string]interface{} {
	fields := make(map[string]interface{})
	for _, field_desc := range d.GetKnownFields() {
	field_name := field_desc.GetName()
	fields[field_name] = d.GetFieldByName(field_name)
	}
	return fields
	}

	// Returns True if a message has been enacted
	func IsEnacted(d *dynamic.Message) bool {
	enacted := d.GetFieldByName("enacted").(float64)
	updated := d.GetFieldByName("updated").(float64)

	return (enacted >= updated)
	}