global secondary indexes

dynamodb/gsi_metadata.odin

@@ -0,0 +1,187 @@
+// gsi_metadata.odin — GSI metadata parsing for serialize/deserialize_table_metadata
+//
+// Parses GSI definitions from the embedded JSON string stored in table metadata.
+// This file lives in the dynamodb/ package.
+package dynamodb
+
+import "core:encoding/json"
+import "core:mem"
+import "core:strings"
+
+// Parse GlobalSecondaryIndexes from a JSON string like:
+// [{"IndexName":"email-index","KeySchema":[{"AttributeName":"email","KeyType":"HASH"}],
+//   "Projection":{"ProjectionType":"ALL"}}]
+//
+// Allocates all strings with the given allocator (engine.allocator for long-lived data).
+parse_gsis_json :: proc(json_str: string, allocator: mem.Allocator) -> ([]Global_Secondary_Index, bool) {
+	data, parse_err := json.parse(transmute([]byte)json_str, allocator = context.temp_allocator)
+	if parse_err != nil {
+		return nil, false
+	}
+	defer json.destroy_value(data)
+
+	arr, ok := data.(json.Array)
+	if !ok {
+		return nil, false
+	}
+
+	if len(arr) == 0 {
+		return nil, true // Empty is valid
+	}
+
+	result := make([]Global_Secondary_Index, len(arr), allocator)
+
+	for elem, i in arr {
+		obj, obj_ok := elem.(json.Object)
+		if !obj_ok {
+			cleanup_gsis(result[:i], allocator)
+			delete(result, allocator)
+			return nil, false
+		}
+
+		gsi, gsi_ok := parse_single_gsi_json(obj, allocator)
+		if !gsi_ok {
+			cleanup_gsis(result[:i], allocator)
+			delete(result, allocator)
+			return nil, false
+		}
+
+		result[i] = gsi
+	}
+
+	return result, true
+}
+
+// Parse a single GSI object from JSON
+@(private = "file")
+parse_single_gsi_json :: proc(obj: json.Object, allocator: mem.Allocator) -> (Global_Secondary_Index, bool) {
+	gsi: Global_Secondary_Index
+
+	// IndexName
+	idx_val, idx_found := obj["IndexName"]
+	if !idx_found {
+		return {}, false
+	}
+	idx_str, idx_ok := idx_val.(json.String)
+	if !idx_ok {
+		return {}, false
+	}
+	gsi.index_name = strings.clone(string(idx_str), allocator)
+
+	// KeySchema
+	ks_val, ks_found := obj["KeySchema"]
+	if !ks_found {
+		delete(gsi.index_name, allocator)
+		return {}, false
+	}
+	ks_arr, ks_ok := ks_val.(json.Array)
+	if !ks_ok || len(ks_arr) == 0 || len(ks_arr) > 2 {
+		delete(gsi.index_name, allocator)
+		return {}, false
+	}
+
+	key_schema := make([]Key_Schema_Element, len(ks_arr), allocator)
+	for ks_elem, j in ks_arr {
+		ks_obj, kobj_ok := ks_elem.(json.Object)
+		if !kobj_ok {
+			for k in 0..<j {
+				delete(key_schema[k].attribute_name, allocator)
+			}
+			delete(key_schema, allocator)
+			delete(gsi.index_name, allocator)
+			return {}, false
+		}
+
+		an_val, an_found := ks_obj["AttributeName"]
+		if !an_found {
+			for k in 0..<j { delete(key_schema[k].attribute_name, allocator) }
+			delete(key_schema, allocator)
+			delete(gsi.index_name, allocator)
+			return {}, false
+		}
+		an_str, an_ok := an_val.(json.String)
+		if !an_ok {
+			for k in 0..<j { delete(key_schema[k].attribute_name, allocator) }
+			delete(key_schema, allocator)
+			delete(gsi.index_name, allocator)
+			return {}, false
+		}
+
+		kt_val, kt_found := ks_obj["KeyType"]
+		if !kt_found {
+			for k in 0..<j { delete(key_schema[k].attribute_name, allocator) }
+			delete(key_schema, allocator)
+			delete(gsi.index_name, allocator)
+			return {}, false
+		}
+		kt_str, kt_ok := kt_val.(json.String)
+		if !kt_ok {
+			for k in 0..<j { delete(key_schema[k].attribute_name, allocator) }
+			delete(key_schema, allocator)
+			delete(gsi.index_name, allocator)
+			return {}, false
+		}
+
+		kt, kt_parse_ok := key_type_from_string(string(kt_str))
+		if !kt_parse_ok {
+			for k in 0..<j { delete(key_schema[k].attribute_name, allocator) }
+			delete(key_schema, allocator)
+			delete(gsi.index_name, allocator)
+			return {}, false
+		}
+
+		key_schema[j] = Key_Schema_Element{
+			attribute_name = strings.clone(string(an_str), allocator),
+			key_type = kt,
+		}
+	}
+	gsi.key_schema = key_schema
+
+	// Projection
+	gsi.projection.projection_type = .ALL // default
+	if proj_val, proj_found := obj["Projection"]; proj_found {
+		if proj_obj, proj_ok := proj_val.(json.Object); proj_ok {
+			if pt_val, pt_found := proj_obj["ProjectionType"]; pt_found {
+				if pt_str, pt_ok := pt_val.(json.String); pt_ok {
+					switch string(pt_str) {
+					case "ALL":       gsi.projection.projection_type = .ALL
+					case "KEYS_ONLY": gsi.projection.projection_type = .KEYS_ONLY
+					case "INCLUDE":   gsi.projection.projection_type = .INCLUDE
+					}
+				}
+			}
+
+			// NonKeyAttributes
+			if nka_val, nka_found := proj_obj["NonKeyAttributes"]; nka_found {
+				if nka_arr, nka_ok := nka_val.(json.Array); nka_ok && len(nka_arr) > 0 {
+					nka := make([]string, len(nka_arr), allocator)
+					for attr_val, k in nka_arr {
+						if attr_str, attr_ok := attr_val.(json.String); attr_ok {
+							nka[k] = strings.clone(string(attr_str), allocator)
+						}
+					}
+					gsi.projection.non_key_attributes = nka
+				}
+			}
+		}
+	}
+
+	return gsi, true
+}
+
+// Clean up partially-constructed GSI array
+cleanup_gsis :: proc(gsis: []Global_Secondary_Index, allocator: mem.Allocator) {
+	for gsi in gsis {
+		delete(gsi.index_name, allocator)
+		for ks in gsi.key_schema {
+			delete(ks.attribute_name, allocator)
+		}
+		delete(gsi.key_schema, allocator)
+		if nka, has_nka := gsi.projection.non_key_attributes.?; has_nka {
+			for attr in nka {
+				delete(attr, allocator)
+			}
+			delete(nka, allocator)
+		}
+	}
+}