gotosocial/vendor/github.com/uptrace/bun/migrate/sqlschema/inspector.go

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package sqlschema
import (
"context"
"fmt"
"strconv"
"strings"
"github.com/uptrace/bun"
"github.com/uptrace/bun/schema"
orderedmap "github.com/wk8/go-ordered-map/v2"
)
type InspectorDialect interface {
schema.Dialect
// Inspector returns a new instance of Inspector for the dialect.
// Dialects MAY set their default InspectorConfig values in constructor
// but MUST apply InspectorOptions to ensure they can be overriden.
//
// Use ApplyInspectorOptions to reduce boilerplate.
NewInspector(db *bun.DB, options ...InspectorOption) Inspector
// CompareType returns true if col1 and co2 SQL types are equivalent,
// i.e. they might use dialect-specifc type aliases (SERIAL ~ SMALLINT)
// or specify the same VARCHAR length differently (VARCHAR(255) ~ VARCHAR).
CompareType(Column, Column) bool
}
// InspectorConfig controls the scope of migration by limiting the objects Inspector should return.
// Inspectors SHOULD use the configuration directly instead of copying it, or MAY choose to embed it,
// to make sure options are always applied correctly.
type InspectorConfig struct {
// SchemaName limits inspection to tables in a particular schema.
SchemaName string
// ExcludeTables from inspection.
ExcludeTables []string
}
// Inspector reads schema state.
type Inspector interface {
Inspect(ctx context.Context) (Database, error)
}
func WithSchemaName(schemaName string) InspectorOption {
return func(cfg *InspectorConfig) {
cfg.SchemaName = schemaName
}
}
// WithExcludeTables works in append-only mode, i.e. tables cannot be re-included.
func WithExcludeTables(tables ...string) InspectorOption {
return func(cfg *InspectorConfig) {
cfg.ExcludeTables = append(cfg.ExcludeTables, tables...)
}
}
// NewInspector creates a new database inspector, if the dialect supports it.
func NewInspector(db *bun.DB, options ...InspectorOption) (Inspector, error) {
dialect, ok := (db.Dialect()).(InspectorDialect)
if !ok {
return nil, fmt.Errorf("%s does not implement sqlschema.Inspector", db.Dialect().Name())
}
return &inspector{
Inspector: dialect.NewInspector(db, options...),
}, nil
}
func NewBunModelInspector(tables *schema.Tables, options ...InspectorOption) *BunModelInspector {
bmi := &BunModelInspector{
tables: tables,
}
ApplyInspectorOptions(&bmi.InspectorConfig, options...)
return bmi
}
type InspectorOption func(*InspectorConfig)
func ApplyInspectorOptions(cfg *InspectorConfig, options ...InspectorOption) {
for _, opt := range options {
opt(cfg)
}
}
// inspector is opaque pointer to a database inspector.
type inspector struct {
Inspector
}
// BunModelInspector creates the current project state from the passed bun.Models.
// Do not recycle BunModelInspector for different sets of models, as older models will not be de-registerred before the next run.
type BunModelInspector struct {
InspectorConfig
tables *schema.Tables
}
var _ Inspector = (*BunModelInspector)(nil)
func (bmi *BunModelInspector) Inspect(ctx context.Context) (Database, error) {
state := BunModelSchema{
BaseDatabase: BaseDatabase{
ForeignKeys: make(map[ForeignKey]string),
},
Tables: orderedmap.New[string, Table](),
}
for _, t := range bmi.tables.All() {
if t.Schema != bmi.SchemaName {
continue
}
columns := orderedmap.New[string, Column]()
for _, f := range t.Fields {
sqlType, length, err := parseLen(f.CreateTableSQLType)
if err != nil {
return nil, fmt.Errorf("parse length in %q: %w", f.CreateTableSQLType, err)
}
columns.Set(f.Name, &BaseColumn{
Name: f.Name,
SQLType: strings.ToLower(sqlType), // TODO(dyma): maybe this is not necessary after Column.Eq()
VarcharLen: length,
DefaultValue: exprToLower(f.SQLDefault),
IsNullable: !f.NotNull,
IsAutoIncrement: f.AutoIncrement,
IsIdentity: f.Identity,
})
}
var unique []Unique
for name, group := range t.Unique {
// Create a separate unique index for single-column unique constraints
// let each dialect apply the default naming convention.
if name == "" {
for _, f := range group {
unique = append(unique, Unique{Columns: NewColumns(f.Name)})
}
continue
}
// Set the name if it is a "unique group", in which case the user has provided the name.
var columns []string
for _, f := range group {
columns = append(columns, f.Name)
}
unique = append(unique, Unique{Name: name, Columns: NewColumns(columns...)})
}
var pk *PrimaryKey
if len(t.PKs) > 0 {
var columns []string
for _, f := range t.PKs {
columns = append(columns, f.Name)
}
pk = &PrimaryKey{Columns: NewColumns(columns...)}
}
// In cases where a table is defined in a non-default schema in the `bun:table` tag,
// schema.Table only extracts the name of the schema, but passes the entire tag value to t.Name
// for backwads-compatibility. For example, a bun model like this:
// type Model struct { bun.BaseModel `bun:"table:favourite.books` }
// produces
// schema.Table{ Schema: "favourite", Name: "favourite.books" }
tableName := strings.TrimPrefix(t.Name, t.Schema+".")
state.Tables.Set(tableName, &BunTable{
BaseTable: BaseTable{
Schema: t.Schema,
Name: tableName,
Columns: columns,
UniqueConstraints: unique,
PrimaryKey: pk,
},
Model: t.ZeroIface,
})
for _, rel := range t.Relations {
// These relations are nominal and do not need a foreign key to be declared in the current table.
// They will be either expressed as N:1 relations in an m2m mapping table, or will be referenced by the other table if it's a 1:N.
if rel.Type == schema.ManyToManyRelation ||
rel.Type == schema.HasManyRelation {
continue
}
var fromCols, toCols []string
for _, f := range rel.BasePKs {
fromCols = append(fromCols, f.Name)
}
for _, f := range rel.JoinPKs {
toCols = append(toCols, f.Name)
}
target := rel.JoinTable
state.ForeignKeys[ForeignKey{
From: NewColumnReference(t.Name, fromCols...),
To: NewColumnReference(target.Name, toCols...),
}] = ""
}
}
return state, nil
}
func parseLen(typ string) (string, int, error) {
paren := strings.Index(typ, "(")
if paren == -1 {
return typ, 0, nil
}
length, err := strconv.Atoi(typ[paren+1 : len(typ)-1])
if err != nil {
return typ, 0, err
}
return typ[:paren], length, nil
}
// exprToLower converts string to lowercase, if it does not contain a string literal 'lit'.
// Use it to ensure that user-defined default values in the models are always comparable
// to those returned by the database inspector, regardless of the case convention in individual drivers.
func exprToLower(s string) string {
if strings.HasPrefix(s, "'") && strings.HasSuffix(s, "'") {
return s
}
return strings.ToLower(s)
}
// BunModelSchema is the schema state derived from bun table models.
type BunModelSchema struct {
BaseDatabase
Tables *orderedmap.OrderedMap[string, Table]
}
func (ms BunModelSchema) GetTables() *orderedmap.OrderedMap[string, Table] {
return ms.Tables
}
// BunTable provides additional table metadata that is only accessible from scanning bun models.
type BunTable struct {
BaseTable
// Model stores the zero interface to the underlying Go struct.
Model interface{}
}