storage

type Engine interface {
	// Opens or creates a database at the resource path
	Open(resource string) error

	// Closes and releases the database resource
	Close() error

	// Lists tables
	Tables() (tables map[string]int32)

	// Make/Get a handle for a table.
	CreateTable(table string) int32

	// Records the table schema for named table
	// Restructuring existing data
	SyncTable(table int32, schema *TableSchemaStructure) error

	Schema(table int32) *TableSchemaStructure

	NewTransaction() (Transaction, error)

	// Release transaction without committing
	Release(transaction Transaction) error

	// Persists the modified state in Transaction to the engine's storage.
	Commit(transaction Transaction) error

	// Transactionless insertion of records
	Insert(table int32, records []Record) error

	// Transactionless count, returning number of records matched
	Count(table int32, expr *query.Expression) (count uint64, err error)

	// Transactionless query, returning matched records
	Query(table int32, expr *query.Expression) (records []Record, err error)

	// Transactionless update, modifying all matched records to have contents of Record
	Update(table int32, expr *query.Expression, columns []int, values []any) (affected_rows uint64, err error)

	// Transactionless delete, returning number of affected rows
	Delete(table int32, expr *query.Expression) (uint64, error)

	// Transactionless iteration through entire table
	Iterate(table int32, iteration Iteration) (err error)
}

type Iteration func(record Record) (continue_iterating bool)

type NewEngineFunc func() Engine

type Record []any

type TableSchemaColumn struct {
	Index         bool                  `json:"index"`          // Index may or may not speed up lookups.
	Exclusive     bool                  `json:"exclusive"`      // When used with Index, Exclusive means that there can only be one index per instance of this column's value
	AutoIncrement bool                  `json:"auto_increment"` // Means that the column is an integer that increases
	Name          string                `json:"name"`
	Tag           uint32                `json:"tag"`
	Size          int32                 `json:"size"`
	Kind          TableSchemaColumnKind `json:"kind"`
	Members       []TableSchemaColumn   `json:"members"`
}

type TableSchemaColumnKind uint8

type TableSchemaRow []TableSchemaColumn

type TableSchemaStructure struct {
	Columns []TableSchemaColumn `json:"columns"`
}

type Transaction interface {
	Count(table int32, expr *query.Expression) (count uint64, err error)
	Query(table int32, expr *query.Expression) (records []Record, err error)
	Insert(table int32, records []Record) error
	Update(table int32, expr *query.Expression, columns []int, values []any) (affected_rows uint64, err error)
	Delete(table int32, expr *query.Expression) (deleted uint64, err error)
	Iterate(table int32, iteration Iteration) (err error)
}