File size: 2,565 Bytes
e089492 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 | package shellconfig
import (
"context"
"encoding/json"
"fmt"
)
// ConfigBuilder accumulates config state as config builtins execute during a
// crushrc load. Builtins mutate the nested map directly, in execution order,
// so imperative operations (append, set, remove, reset) resolve exactly as the
// script intends. The builder is stored on the shell context so builtins can
// reach it; it is absent during normal bash tool execution, which makes the
// config builtins no-ops there.
//
// At the end of a script the builder marshals to a single JSON object, which
// the config loader merges with any other config files.
type ConfigBuilder struct {
root map[string]any
}
// newConfigBuilder returns an empty builder.
func newConfigBuilder() *ConfigBuilder {
return &ConfigBuilder{root: make(map[string]any)}
}
// section returns the top-level object stored at key, creating it if absent.
// Panics if the existing value is non-nil and not a map: that invariant
// violation indicates a bug in a builtin handler, not user error.
func (b *ConfigBuilder) section(key string) map[string]any {
m, ok := b.root[key].(map[string]any)
if !ok {
if b.root[key] != nil {
panic(fmt.Sprintf("shellconfig: section(%q) overwrites non-map value %T", key, b.root[key]))
}
m = make(map[string]any)
b.root[key] = m
}
return m
}
// empty reports whether the builder holds no config.
func (b *ConfigBuilder) empty() bool {
return len(b.root) == 0
}
// JSON marshals the accumulated config to a single JSON object.
func (b *ConfigBuilder) JSON() ([]byte, error) {
return json.Marshal(b.root)
}
// childMap returns/creates the nested object parent[key].
// Panics if the existing value is non-nil and not a map, same invariant as
// section().
func childMap(parent map[string]any, key string) map[string]any {
m, ok := parent[key].(map[string]any)
if !ok {
if parent[key] != nil {
panic(fmt.Sprintf("shellconfig: childMap(%q) overwrites non-map value %T", key, parent[key]))
}
m = make(map[string]any)
parent[key] = m
}
return m
}
type configBuilderCtxKey struct{}
// configBuilderFromCtx returns the ConfigBuilder on the context, or nil if
// none is present (normal bash tool execution).
func configBuilderFromCtx(ctx context.Context) *ConfigBuilder {
v, _ := ctx.Value(configBuilderCtxKey{}).(*ConfigBuilder)
return v
}
// withConfigBuilder returns a context carrying the given ConfigBuilder.
func withConfigBuilder(ctx context.Context, b *ConfigBuilder) context.Context {
return context.WithValue(ctx, configBuilderCtxKey{}, b)
}
|