iceberg: switch to string_view

Switches serialization interfaces to use std::string_view instead of
const sstring&, as it's more generic.

src/v/iceberg/manifest_avro.cc

@@ -35,9 +35,9 @@
 namespace iceberg {
 
 namespace {
-schema schema_from_str(const std::string& s) {
+schema schema_from_str(std::string_view s) {
     json::Document parsed_schema;
-    parsed_schema.Parse(s);
+    parsed_schema.Parse(s.data(), s.size());
     return parse_schema(parsed_schema);
 }
 

src/v/iceberg/schema_avro.cc

@@ -188,8 +188,8 @@ avro::Schema field_to_avro(const nested_field& field) {
 }
 
 avro::Schema
-struct_type_to_avro(const struct_type& type, const ss::sstring& name) {
-    avro::RecordSchema avro_schema(name);
+struct_type_to_avro(const struct_type& type, std::string_view name) {
+    avro::RecordSchema avro_schema(std::string{name});
     const auto& fields = type.fields;
     for (const auto& field_ptr : fields) {
         const auto child_schema = field_to_avro(*field_ptr);

src/v/iceberg/schema_avro.h

@@ -20,7 +20,7 @@ namespace iceberg {
 // The resulting schema is annotated with Iceberg attributes (e.g. 'field-id',
 // 'element-id').
 avro::Schema field_to_avro(const nested_field& field);
-avro::Schema struct_type_to_avro(const struct_type&, const ss::sstring& name);
+avro::Schema struct_type_to_avro(const struct_type&, std::string_view name);
 
 // Translates the given Avro schema into its corresponding field/type, throwing
 // an exception if the schema is not a valid Iceberg schema (e.g. missing

src/v/iceberg/snapshot_json.cc

@@ -34,7 +34,7 @@ constexpr std::string_view operation_to_str(snapshot_operation o) {
     }
 }
 
-snapshot_operation operation_from_str(const ss::sstring& operation_str) {
+snapshot_operation operation_from_str(std::string_view operation_str) {
     using enum snapshot_operation;
     return string_switch<snapshot_operation>(operation_str)
       .match(operation_to_str(append), append)
@@ -53,7 +53,7 @@ constexpr std::string_view ref_type_to_str(snapshot_ref_type t) {
     }
 }
 
-snapshot_ref_type ref_type_from_str(const ss::sstring& ref_type_str) {
+snapshot_ref_type ref_type_from_str(std::string_view ref_type_str) {
     using enum snapshot_ref_type;
     return string_switch<snapshot_ref_type>(ref_type_str)
       .match(ref_type_to_str(tag), tag)

src/v/iceberg/transform_json.cc

@@ -39,7 +39,7 @@ ss::sstring transform_to_str(const transform& t) {
     return std::visit(transform_str_visitor{}, t);
 }
 
-transform transform_from_str(const ss::sstring& s) {
+transform transform_from_str(std::string_view s) {
     if (s.starts_with("bucket")) {
         auto n_str = extract_between('[', ']', s);
         auto n = std::stoul(ss::sstring(n_str));

src/v/iceberg/transform_json.h

@@ -18,6 +18,6 @@ namespace iceberg {
 // NOTE: while there are no complex JSON types here, the transforms are
 // expected to be serialized as a part of JSON files (e.g. table metadata).
 ss::sstring transform_to_str(const transform&);
-transform transform_from_str(const ss::sstring&);
+transform transform_from_str(std::string_view);
 
 } // namespace iceberg