refactor: Deprecate CollectionDescription.Schema (sourcenetwork#1939)

## Relevant issue(s)

Resolves sourcenetwork#1955

## Description

Deprecate CollectionDescription.Schema. Schema is not a sub-property of
collection.

Removes as many references to CollectionDescription.Schema as possible
without making any breaking changes. Breaking changes will be made in a
later PR. An exception has been made to the http API, which does have a
breaking change in this PR.

cli/collection_describe.go

@@ -39,16 +39,16 @@ Example: view collection by version id
 
 			col, ok := tryGetCollectionContext(cmd)
 			if ok {
-				return writeJSON(cmd, col.Description())
+				return writeJSON(cmd, col.Definition())
 			}
 			// if no collection specified list all collections
 			cols, err := store.GetAllCollections(cmd.Context())
 			if err != nil {
 				return err
 			}
-			colDesc := make([]client.CollectionDescription, len(cols))
+			colDesc := make([]client.CollectionDefinition, len(cols))
 			for i, col := range cols {
-				colDesc[i] = col.Description()
+				colDesc[i] = col.Definition()
 			}
 			return writeJSON(cmd, colDesc)
 		},

client/collection.go

@@ -16,24 +16,35 @@ import (
 	"github.com/sourcenetwork/defradb/datastore"
 )
 
+// CollectionDefinition contains the metadata defining what a Collection is.
+type CollectionDefinition struct {
+	// Description returns the CollectionDescription of this Collection.
+	Description CollectionDescription `json:"description"`
+	// Schema returns the SchemaDescription used to define this Collection.
+	Schema SchemaDescription `json:"schema"`
+}
+
 // Collection represents a defradb collection.
 //
 // A Collection is mostly analogous to a SQL table, however a collection is specific to its
 // host, and many collections may share the same schema.
 //
 // Many functions on this object will interact with the underlying datastores.
 type Collection interface {
-	// Description returns the CollectionDescription of this Collection.
-	Description() CollectionDescription
 	// Name returns the name of this collection.
 	Name() string
-	// Schema returns the SchemaDescription used to define this Collection.
-	Schema() SchemaDescription
 	// ID returns the ID of this Collection.
 	ID() uint32
 	// SchemaID returns the ID of the Schema used to define this Collection.
 	SchemaID() string
 
+	// Definition contains the metadata defining what a Collection is.
+	Definition() CollectionDefinition
+	// Schema returns the SchemaDescription used to define this Collection.
+	Schema() SchemaDescription
+	// Description returns the CollectionDescription of this Collection.
+	Description() CollectionDescription
+
 	// Create a new document.
 	//
 	// Will verify the DocKey/CID to ensure that the new document is correctly formatted.

client/descriptions.go

@@ -28,6 +28,8 @@ type CollectionDescription struct {
 	ID uint32
 
 	// Schema contains the data type information that this Collection uses.
+	//
+	// This property is deprecated and should not be used.
 	Schema SchemaDescription
 
 	// Indexes contains the secondary indexes that this Collection has.
@@ -41,12 +43,21 @@ func (col CollectionDescription) IDString() string {
 
 // GetFieldByID searches for a field with the given ID. If such a field is found it
 // will return it and true, if it is not found it will return false.
-func (col CollectionDescription) GetFieldByID(id FieldID) (FieldDescription, bool) {
-	if !col.Schema.IsEmpty() {
-		for _, field := range col.Schema.Fields {
-			if field.ID == id {
-				return field, true
-			}
+func (col CollectionDescription) GetFieldByID(id FieldID, schema *SchemaDescription) (FieldDescription, bool) {
+	for _, field := range schema.Fields {
+		if field.ID == id {
+			return field, true
+		}
+	}
+	return FieldDescription{}, false
+}
+
+// GetFieldByName returns the field for the given field name. If such a field is found it
+// will return it and true, if it is not found it will return false.
+func (col CollectionDescription) GetFieldByName(fieldName string, schema *SchemaDescription) (FieldDescription, bool) {
+	for _, field := range schema.Fields {
+		if field.Name == fieldName {
+			return field, true
 		}
 	}
 	return FieldDescription{}, false
@@ -57,8 +68,9 @@ func (col CollectionDescription) GetFieldByRelation(
 	relationName string,
 	otherCollectionName string,
 	otherFieldName string,
+	schema *SchemaDescription,
 ) (FieldDescription, bool) {
-	for _, field := range col.Schema.Fields {
+	for _, field := range schema.Fields {
 		if field.RelationName == relationName && !(col.Name == otherCollectionName && otherFieldName == field.Name) {
 			return field, true
 		}
@@ -93,28 +105,11 @@ type SchemaDescription struct {
 	Fields []FieldDescription
 }
 
-// IsEmpty returns true if the SchemaDescription is empty and uninitialized
-func (sd SchemaDescription) IsEmpty() bool {
-	return len(sd.Fields) == 0
-}
-
-// GetFieldKey returns the field ID for the given field name.
-func (sd SchemaDescription) GetFieldKey(fieldName string) uint32 {
-	for _, field := range sd.Fields {
-		if field.Name == fieldName {
-			return uint32(field.ID)
-		}
-	}
-	return uint32(0)
-}
-
 // GetField returns the field of the given name.
 func (sd SchemaDescription) GetField(name string) (FieldDescription, bool) {
-	if !sd.IsEmpty() {
-		for _, field := range sd.Fields {
-			if field.Name == name {
-				return field, true
-			}
+	for _, field := range sd.Fields {
+		if field.Name == name {
+			return field, true
 		}
 	}
 	return FieldDescription{}, false

core/parser.go

@@ -51,8 +51,8 @@ type Parser interface {
 	NewFilterFromString(collectionType string, body string) (immutable.Option[request.Filter], error)
 
 	// ParseSDL parses an SDL string into a set of collection descriptions.
-	ParseSDL(ctx context.Context, schemaString string) ([]client.CollectionDescription, error)
+	ParseSDL(ctx context.Context, schemaString string) ([]client.CollectionDefinition, error)
 
 	// Adds the given schema to this parser's model.
-	SetSchema(ctx context.Context, txn datastore.Txn, collections []client.CollectionDescription) error
+	SetSchema(ctx context.Context, txn datastore.Txn, collections []client.CollectionDefinition) error
 }

db/base/collection_keys.go

@@ -34,6 +34,7 @@ func MakeDocKey(col client.CollectionDescription, docKey string) core.DataStoreK
 
 func MakePrimaryIndexKeyForCRDT(
 	c client.CollectionDescription,
+	schema client.SchemaDescription,
 	ctype client.CType,
 	key core.DataStoreKey,
 	fieldName string,
@@ -42,19 +43,12 @@ func MakePrimaryIndexKeyForCRDT(
 	case client.COMPOSITE:
 		return MakeCollectionKey(c).WithInstanceInfo(key).WithFieldId(core.COMPOSITE_NAMESPACE), nil
 	case client.LWW_REGISTER:
-		fieldKey := getFieldKey(c, key, fieldName)
-		return MakeCollectionKey(c).WithInstanceInfo(fieldKey), nil
-	}
-	return core.DataStoreKey{}, ErrInvalidCrdtType
-}
+		field, ok := c.GetFieldByName(fieldName, &schema)
+		if !ok {
+			return core.DataStoreKey{}, client.NewErrFieldNotExist(fieldName)
+		}
 
-func getFieldKey(
-	c client.CollectionDescription,
-	key core.DataStoreKey,
-	fieldName string,
-) core.DataStoreKey {
-	if !c.Schema.IsEmpty() {
-		return key.WithFieldId(fmt.Sprint(c.Schema.GetFieldKey(fieldName)))
+		return MakeCollectionKey(c).WithInstanceInfo(key).WithFieldId(fmt.Sprint(field.ID)), nil
 	}
-	return key.WithFieldId(fieldName)
+	return core.DataStoreKey{}, ErrInvalidCrdtType
 }