Documentation
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Overview ¶
Package postgresql implements the provider.Provider interface for PostgreSQL configuration backends. It polls a database table at a configurable interval to sync dynamic configuration values. Supports custom Repository implementations for non-standard table schemas. All keys are fetched in a single query per poll cycle for efficiency.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Config ¶
type Config struct {
// Repository is the data access layer. If nil, a DefaultRepository
// must be provided via the DB/Table/KeyColumn/ValueColumn fields.
Repository Repository
// DB is an existing [*sql.DB] connection. Users manage the lifecycle
// (open, close, connection pooling) themselves.
// Only used when Repository is nil.
DB *sql.DB
// TableName is the table to query. Default: "config".
// Only used when Repository is nil.
TableName string
// KeyColumn is the column name for config keys. Default: "config_key".
// Only used when Repository is nil.
KeyColumn string
// ValueColumn is the column name for config values. Default: "config_value".
// Only used when Repository is nil.
ValueColumn string
// PollInterval is how often to check for changes. Default: 5s.
PollInterval time.Duration
}
Config holds PostgreSQL-specific configuration.
type DefaultRepository ¶
type DefaultRepository struct {
// contains filtered or unexported fields
}
DefaultRepository provides a simple key-value query against a PostgreSQL table.
func NewDefaultRepository ¶
func NewDefaultRepository(db *sql.DB, table, keyColumn, valueColumn string) *DefaultRepository
NewDefaultRepository creates the default repository that queries a key-value table. The table is expected to have at least a key column and a value column. Example schema:
CREATE TABLE config (
config_key VARCHAR(255) PRIMARY KEY,
config_value TEXT
);
type Provider ¶
type Provider struct {
// contains filtered or unexported fields
}
Provider implements the poya Provider interface using polling against PostgreSQL. All keys are fetched in a single query per poll cycle.
func New ¶
New creates a new PostgreSQL provider. Pass a Config with either a custom Repository or a pre-configured *sql.DB.
Using the default repository:
provider, err := postgresql.New(postgresql.Config{
DB: db,
TableName: "config",
KeyColumn: "config_key",
ValueColumn: "config_value",
PollInterval: 5 * time.Second,
})
Using a custom repository:
provider, err := postgresql.New(postgresql.Config{
Repository: myCustomRepo,
PollInterval: 5 * time.Second,
})
func (*Provider) Close ¶
Close releases PostgreSQL provider resources. Note: the *sql.DB is managed by the caller and is not closed here.
func (*Provider) Watch ¶
func (p *Provider) Watch(ctx context.Context, keys []string, onChange func(key string, value string), onDelete func(key string)) error
Watch polls all keys at the configured interval using a single query. When any value changes, onChange is called with the key and new value. When a key is deleted from the table, onDelete is called so the SDK reverts it to its default.
type Repository ¶
type Repository interface {
Get(ctx context.Context, key string) (string, error)
GetAll(ctx context.Context, keys []string) (map[string]string, error)
}
Repository defines how config values are read from PostgreSQL. Users can implement this interface for custom table schemas, or use the DefaultRepository for a simple key-value table.
Source Files