terraform/internal/legacy/helper/schema/field_writer_map.go

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package schema
import (
"fmt"
"reflect"
"strconv"
"strings"
"sync"
"github.com/mitchellh/mapstructure"
)
// MapFieldWriter writes data into a single map[string]string structure.
type MapFieldWriter struct {
Schema map[string]*Schema
lock sync.Mutex
result map[string]string
}
// Map returns the underlying map that is being written to.
func (w *MapFieldWriter) Map() map[string]string {
w.lock.Lock()
defer w.lock.Unlock()
if w.result == nil {
w.result = make(map[string]string)
}
return w.result
}
func (w *MapFieldWriter) unsafeWriteField(addr string, value string) {
w.lock.Lock()
defer w.lock.Unlock()
if w.result == nil {
w.result = make(map[string]string)
}
w.result[addr] = value
}
// clearTree clears a field and any sub-fields of the given address out of the
// map. This should be used to reset some kind of complex structures (namely
// sets) before writing to make sure that any conflicting data is removed (for
// example, if the set was previously written to the writer's layer).
func (w *MapFieldWriter) clearTree(addr []string) {
prefix := strings.Join(addr, ".") + "."
for k := range w.result {
if strings.HasPrefix(k, prefix) {
delete(w.result, k)
}
}
}
func (w *MapFieldWriter) WriteField(addr []string, value interface{}) error {
w.lock.Lock()
defer w.lock.Unlock()
if w.result == nil {
w.result = make(map[string]string)
}
schemaList := addrToSchema(addr, w.Schema)
if len(schemaList) == 0 {
return fmt.Errorf("Invalid address to set: %#v", addr)
}
// If we're setting anything other than a list root or set root,
// then disallow it.
for _, schema := range schemaList[:len(schemaList)-1] {
if schema.Type == TypeList {
return fmt.Errorf(
"%s: can only set full list",
strings.Join(addr, "."))
}
if schema.Type == TypeMap {
return fmt.Errorf(
"%s: can only set full map",
strings.Join(addr, "."))
}
if schema.Type == TypeSet {
return fmt.Errorf(
"%s: can only set full set",
strings.Join(addr, "."))
}
}
return w.set(addr, value)
}
func (w *MapFieldWriter) set(addr []string, value interface{}) error {
schemaList := addrToSchema(addr, w.Schema)
if len(schemaList) == 0 {
return fmt.Errorf("Invalid address to set: %#v", addr)
}
schema := schemaList[len(schemaList)-1]
switch schema.Type {
case TypeBool, TypeInt, TypeFloat, TypeString:
return w.setPrimitive(addr, value, schema)
case TypeList:
return w.setList(addr, value, schema)
case TypeMap:
return w.setMap(addr, value, schema)
case TypeSet:
return w.setSet(addr, value, schema)
case typeObject:
return w.setObject(addr, value, schema)
default:
panic(fmt.Sprintf("Unknown type: %#v", schema.Type))
}
}
func (w *MapFieldWriter) setList(
addr []string,
v interface{},
schema *Schema) error {
k := strings.Join(addr, ".")
setElement := func(idx string, value interface{}) error {
addrCopy := make([]string, len(addr), len(addr)+1)
copy(addrCopy, addr)
return w.set(append(addrCopy, idx), value)
}
var vs []interface{}
if err := mapstructure.Decode(v, &vs); err != nil {
return fmt.Errorf("%s: %s", k, err)
}
// Wipe the set from the current writer prior to writing if it exists.
// Multiple writes to the same layer is a lot safer for lists than sets due
// to the fact that indexes are always deterministic and the length will
// always be updated with the current length on the last write, but making
// sure we have a clean namespace removes any chance for edge cases to pop up
// and ensures that the last write to the set is the correct value.
w.clearTree(addr)
// Set the entire list.
var err error
for i, elem := range vs {
is := strconv.FormatInt(int64(i), 10)
err = setElement(is, elem)
if err != nil {
break
}
}
if err != nil {
for i, _ := range vs {
is := strconv.FormatInt(int64(i), 10)
setElement(is, nil)
}
return err
}
w.result[k+".#"] = strconv.FormatInt(int64(len(vs)), 10)
return nil
}
func (w *MapFieldWriter) setMap(
addr []string,
value interface{},
schema *Schema) error {
k := strings.Join(addr, ".")
v := reflect.ValueOf(value)
vs := make(map[string]interface{})
if value == nil {
// The empty string here means the map is removed.
w.result[k] = ""
return nil
}
if v.Kind() != reflect.Map {
return fmt.Errorf("%s: must be a map", k)
}
if v.Type().Key().Kind() != reflect.String {
return fmt.Errorf("%s: keys must strings", k)
}
for _, mk := range v.MapKeys() {
mv := v.MapIndex(mk)
vs[mk.String()] = mv.Interface()
}
// Wipe this address tree. The contents of the map should always reflect the
// last write made to it.
w.clearTree(addr)
// Remove the pure key since we're setting the full map value
delete(w.result, k)
// Set each subkey
addrCopy := make([]string, len(addr), len(addr)+1)
copy(addrCopy, addr)
for subKey, v := range vs {
if err := w.set(append(addrCopy, subKey), v); err != nil {
return err
}
}
// Set the count
w.result[k+".%"] = strconv.Itoa(len(vs))
return nil
}
func (w *MapFieldWriter) setObject(
addr []string,
value interface{},
schema *Schema) error {
// Set the entire object. First decode into a proper structure
var v map[string]interface{}
if err := mapstructure.Decode(value, &v); err != nil {
return fmt.Errorf("%s: %s", strings.Join(addr, "."), err)
}
// Make space for additional elements in the address
addrCopy := make([]string, len(addr), len(addr)+1)
copy(addrCopy, addr)
// Set each element in turn
var err error
for k1, v1 := range v {
if err = w.set(append(addrCopy, k1), v1); err != nil {
break
}
}
if err != nil {
for k1, _ := range v {
w.set(append(addrCopy, k1), nil)
}
}
return err
}
func (w *MapFieldWriter) setPrimitive(
addr []string,
v interface{},
schema *Schema) error {
k := strings.Join(addr, ".")
if v == nil {
// The empty string here means the value is removed.
w.result[k] = ""
return nil
}
var set string
switch schema.Type {
case TypeBool:
var b bool
if err := mapstructure.Decode(v, &b); err != nil {
return fmt.Errorf("%s: %s", k, err)
}
set = strconv.FormatBool(b)
case TypeString:
if err := mapstructure.Decode(v, &set); err != nil {
return fmt.Errorf("%s: %s", k, err)
}
case TypeInt:
var n int
if err := mapstructure.Decode(v, &n); err != nil {
return fmt.Errorf("%s: %s", k, err)
}
set = strconv.FormatInt(int64(n), 10)
case TypeFloat:
var n float64
if err := mapstructure.Decode(v, &n); err != nil {
return fmt.Errorf("%s: %s", k, err)
}
set = strconv.FormatFloat(float64(n), 'G', -1, 64)
default:
return fmt.Errorf("Unknown type: %#v", schema.Type)
}
w.result[k] = set
return nil
}
func (w *MapFieldWriter) setSet(
addr []string,
value interface{},
schema *Schema) error {
addrCopy := make([]string, len(addr), len(addr)+1)
copy(addrCopy, addr)
k := strings.Join(addr, ".")
if value == nil {
w.result[k+".#"] = "0"
return nil
}
// If it is a slice, then we have to turn it into a *Set so that
// we get the proper order back based on the hash code.
if v := reflect.ValueOf(value); v.Kind() == reflect.Slice {
// Build a temp *ResourceData to use for the conversion
tempAddr := addr[len(addr)-1:]
tempSchema := *schema
tempSchema.Type = TypeList
tempSchemaMap := map[string]*Schema{tempAddr[0]: &tempSchema}
tempW := &MapFieldWriter{Schema: tempSchemaMap}
// Set the entire list, this lets us get values out of it
if err := tempW.WriteField(tempAddr, value); err != nil {
return err
}
// Build the set by going over the list items in order and
// hashing them into the set. The reason we go over the list and
// not the `value` directly is because this forces all types
// to become []interface{} (generic) instead of []string, which
// most hash functions are expecting.
s := schema.ZeroValue().(*Set)
tempR := &MapFieldReader{
Map: BasicMapReader(tempW.Map()),
Schema: tempSchemaMap,
}
for i := 0; i < v.Len(); i++ {
is := strconv.FormatInt(int64(i), 10)
result, err := tempR.ReadField(append(tempAddr, is))
if err != nil {
return err
}
if !result.Exists {
panic("set item just set doesn't exist")
}
s.Add(result.Value)
}
value = s
}
// Clear any keys that match the set address first. This is necessary because
// it's always possible and sometimes may be necessary to write to a certain
// writer layer more than once with different set data each time, which will
// lead to different keys being inserted, which can lead to determinism
// problems when the old data isn't wiped first.
w.clearTree(addr)
if value.(*Set) == nil {
w.result[k+".#"] = "0"
return nil
}
for code, elem := range value.(*Set).m {
if err := w.set(append(addrCopy, code), elem); err != nil {
return err
}
}
w.result[k+".#"] = strconv.Itoa(value.(*Set).Len())
return nil
}