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parse.go
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parse.go
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package data
import (
"encoding"
"encoding/base64"
"fmt"
"reflect"
"github.com/ipfs/go-cid"
)
func parseFloat(f float64) (int64, error) {
if f != float64(int64(f)) {
return 0, fmt.Errorf("number was is not a safe integer: %f", f)
}
return int64(f), nil
}
func parseAtom(atom any) (any, error) {
switch v := atom.(type) {
case nil:
return v, nil
case bool:
return v, nil
case *bool:
return *v, nil
case int64:
return v, nil
case *int64:
return *v, nil
case int:
return int64(v), nil
case *int:
return int64(*v), nil
case float64:
return parseFloat(v)
case *float64:
return parseFloat(*v)
case string:
if len(v) > MAX_RECORD_STRING_LEN {
return nil, fmt.Errorf("string too long: %d", len(v))
}
return v, nil
case *string:
return parseAtom(*v)
case cid.Cid:
return CIDLink(v), nil
case *cid.Cid:
return CIDLink(*v), nil
case []byte:
return Bytes(v), nil
case *[]byte:
return Bytes(*v), nil
case []any:
return parseArray(v)
case *[]any:
return parseArray(*v)
case map[string]any:
return parseMap(v)
case *map[string]any:
return parseMap(*v)
case encoding.TextMarshaler:
s, err := v.MarshalText()
if err != nil {
return nil, fmt.Errorf("failed to marshal text (%s): %w", reflect.TypeOf(v), err)
}
return s, nil
default:
return nil, fmt.Errorf("unexpected type: %s", reflect.TypeOf(v))
}
}
func parseArray(l []any) ([]any, error) {
if len(l) > MAX_CBOR_CONTAINER_LEN {
return nil, fmt.Errorf("data array length too long: %d", len(l))
}
out := make([]any, len(l))
for i, v := range l {
p, err := parseAtom(v)
if err != nil {
return nil, err
}
out[i] = p
}
return out, nil
}
func parseMap(obj map[string]any) (any, error) {
if len(obj) > MAX_CBOR_CONTAINER_LEN {
return nil, fmt.Errorf("data object has too many fields: %d", len(obj))
}
if _, ok := obj["$link"]; ok {
return parseLink(obj)
}
if _, ok := obj["$bytes"]; ok {
return parseBytes(obj)
}
if typeVal, ok := obj["$type"]; ok {
if typeStr, ok := typeVal.(string); ok {
if typeStr == "blob" {
b, err := parseBlob(obj)
if err != nil {
return nil, err
}
return *b, nil
}
if len(typeStr) == 0 {
return nil, fmt.Errorf("$type field must contain a non-empty string")
}
} else {
return nil, fmt.Errorf("$type field must contain a non-empty string")
}
}
out := make(map[string]any, len(obj))
for k, val := range obj {
if len(k) > MAX_OBJECT_KEY_LEN {
return nil, fmt.Errorf("data object key too long: %d", len(k))
}
atom, err := parseAtom(val)
if err != nil {
return nil, err
}
out[k] = atom
}
return out, nil
}
func parseLink(obj map[string]any) (CIDLink, error) {
var zero CIDLink
if len(obj) != 1 {
return zero, fmt.Errorf("$link objects must have a single field")
}
v, ok := obj["$link"].(string)
if !ok {
return zero, fmt.Errorf("$link field missing or not a string")
}
c, err := cid.Parse(v)
if err != nil {
return zero, fmt.Errorf("invalid $link CID: %w", err)
}
if !c.Defined() {
return zero, fmt.Errorf("undefined (null) CID in $link")
}
return CIDLink(c), nil
}
func parseBytes(obj map[string]any) (Bytes, error) {
if len(obj) != 1 {
return nil, fmt.Errorf("$bytes objects must have a single field")
}
v, ok := obj["$bytes"].(string)
if !ok {
return nil, fmt.Errorf("$bytes field missing or not a string")
}
b, err := base64.RawStdEncoding.DecodeString(v)
if err != nil {
return nil, fmt.Errorf("decoding $byte value: %w", err)
}
return Bytes(b), nil
}
// NOTE: doesn't handle legacy blobs yet!
func parseBlob(obj map[string]any) (*Blob, error) {
if len(obj) != 4 {
return nil, fmt.Errorf("blobs expected to have 4 fields")
}
if obj["$type"] != "blob" {
return nil, fmt.Errorf("blobs expected to have $type=blob")
}
var size int64
var err error
switch v := obj["size"].(type) {
case int:
size = int64(v)
case int64:
size = v
case float64:
size, err = parseFloat(v)
if err != nil {
return nil, err
}
default:
return nil, fmt.Errorf("blob 'size' missing or not a number")
}
mimeType, ok := obj["mimeType"].(string)
if !ok {
return nil, fmt.Errorf("blob 'mimeType' missing or not a string")
}
rawRef, ok := obj["ref"]
if !ok {
return nil, fmt.Errorf("blob 'ref' missing")
}
var ref CIDLink
switch v := rawRef.(type) {
case map[string]any:
cl, err := parseLink(v)
if err != nil {
return nil, err
}
ref = cl
case cid.Cid:
ref = CIDLink(v)
case CIDLink:
ref = v
default:
return nil, fmt.Errorf("blob 'ref' unexpected type")
}
return &Blob{
Size: size,
MimeType: mimeType,
Ref: ref,
}, nil
}
func parseObject(obj map[string]any) (map[string]any, error) {
out, err := parseMap(obj)
if err != nil {
return nil, err
}
if outObj, ok := out.(map[string]any); ok {
return outObj, nil
}
return nil, fmt.Errorf("top-level datum was not an object")
}