nastra commented on code in PR #11: URL: https://github.com/apache/iceberg-go/pull/11#discussion_r1354295034
########## table/metadata.go: ########## @@ -0,0 +1,401 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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 table + +import ( + "encoding/json" + "errors" + "fmt" + "io" + + "github.com/apache/iceberg-go" + + "github.com/google/uuid" +) + +// Metadata for an iceberg table as specified in the Iceberg spec +// +// https://iceberg.apache.org/spec/#iceberg-table-spec +type Metadata interface { + // Version indicates the version of this metadata, 1 for V1, 2 for V2, etc. + Version() int + // TableUUID returns a UUID that identifies the table, generated when the + // table is created. Implementations must throw an exception if a table's + // UUID does not match the expected UUID after refreshing metadata. + TableUUID() uuid.UUID + // Location is the table's base location. This is used by writers to determine + // where to store data files, manifest files, and table metadata files. + Location() string + // LastUpdatedMillis is the timestamp in milliseconds from the unix epoch when + // the table was last updated. Each table metadata file should update this + // field just before writing. + LastUpdatedMillis() int64 + // LastColumn returns the highest assigned column ID for the table. + // This is used to ensure fields are always assigned an unused ID when + // evolving schemas. + LastColumn() int + // Schemas returns the list of schemas, stored as objects with their + // schema-id. + Schemas() []*iceberg.Schema + // CurrentSchema returns the table's current schema. + CurrentSchema() *iceberg.Schema + // PartitionSpecs returns the list of all partition specs in the table. + PartitionSpecs() []iceberg.PartitionSpec + // PartitionSpec returns the current partition spec that the table is using. + PartitionSpec() iceberg.PartitionSpec + // DefaultPartitionSpec is the ID of the current spec that writers should + // use by default. + DefaultPartitionSpec() int + // LastPartitionSpecID is the highest assigned partition field ID across + // all partition specs for the table. This is used to ensure partition + // fields are always assigned an unused ID when evolving specs. + LastPartitionSpecID() *int + // Snapshots returns the list of valid snapshots. Valid snapshots are + // snapshots for which all data files exist in the file system. A data + // file must not be deleted from the file system until the last snapshot + // in which it was listed is garbage collected. + Snapshots() []Snapshot + // SnapshotByID find and return a specific snapshot by its ID. Returns + // nil if the ID is not found in the list of snapshots. + SnapshotByID(int64) *Snapshot + // SnapshotByName searches the list of snapshots for a snapshot with a given + // ref name. Returns nil if there's no ref with this name for a snapshot. + SnapshotByName(name string) *Snapshot + // CurrentSnapshot returns the table's current snapshot. + CurrentSnapshot() *Snapshot + // SortOrder returns the table's current sort order, ie: the one with the + // ID that matches the default-sort-order-id. + SortOrder() SortOrder + // SortOrders returns the list of sort orders in the table. + SortOrders() []SortOrder + // Properties is a string to string map of table properties. This is used + // to control settings that affect reading and writing and is not intended + // to be used for arbitrary metadata. For example, commit.retry.num-retries + // is used to control the number of commit retries. + Properties() iceberg.Properties +} + +var ( + ErrInvalidMetadataFormatVersion = errors.New("invalid or missing format-version in table metadata") + ErrInvalidMetadata = errors.New("invalid metadata") +) + +// ParseMetadata parses json metadata provided by the passed in reader, +// returning an error if one is encountered. +func ParseMetadata(r io.Reader) (Metadata, error) { + data, err := io.ReadAll(r) + if err != nil { + return nil, err + } + + return ParseMetadataBytes(data) +} + +// ParseMetadataString is like [ParseMetadata], but for a string rather than +// an io.Reader. +func ParseMetadataString(s string) (Metadata, error) { + return ParseMetadataBytes([]byte(s)) +} + +// ParseMetadataBytes is like [ParseMetadataString] but for a byte slice. +func ParseMetadataBytes(b []byte) (Metadata, error) { + ver := struct { + FormatVersion int `json:"format-version"` + }{} + if err := json.Unmarshal(b, &ver); err != nil { + return nil, err + } + + var ret Metadata + switch ver.FormatVersion { + case 1: + ret = &MetadataV1{} + case 2: + ret = &MetadataV2{} + default: + return nil, ErrInvalidMetadataFormatVersion + } + + return ret, json.Unmarshal(b, ret) +} + +// https://iceberg.apache.org/spec/#iceberg-table-spec +type commonMetadata struct { + FormatVersion int `json:"format-version"` + UUID uuid.UUID `json:"table-uuid"` + Loc string `json:"location"` + LastUpdatedMS int64 `json:"last-updated-ms"` + LastColumnID int `json:"last-column-id"` + SchemaList []*iceberg.Schema `json:"schemas"` + CurrentSchemaID int `json:"current-schema-id"` + Specs []iceberg.PartitionSpec `json:"partition-specs"` + DefaultSpecID int `json:"default-spec-id"` + LastPartitionID *int `json:"last-partition-id,omitempty"` + Props iceberg.Properties `json:"properties"` + SnapshotList []Snapshot `json:"snapshots,omitempty"` + CurrentSnapshotID *int64 `json:"current-snapshot-id,omitempty"` + SnapshotLog []SnapshotLogEntry `json:"snapshot-log"` + MetadataLog []MetadataLogEntry `json:"metadata-log"` + SortOrderList []SortOrder `json:"sort-orders"` + DefaultSortOrderID int `json:"default-sort-order-id"` + Refs map[string]SnapshotRef `json:"refs"` +} + +func (c *commonMetadata) TableUUID() uuid.UUID { return c.UUID } +func (c *commonMetadata) Location() string { return c.Loc } +func (c *commonMetadata) LastUpdatedMillis() int64 { return c.LastUpdatedMS } +func (c *commonMetadata) LastColumn() int { return c.LastColumnID } Review Comment: imo this should be named `LastColumnID()` -- This is an automated message from the Apache Git Service. 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