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// Copyright 2015 xeipuuv ( https://github.com/xeipuuv )
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// author xeipuuv
// author-github https://github.com/xeipuuv
// author-mail xeipuuv@gmail.com
//
// repository-name gojsonschema
// repository-desc An implementation of JSON Schema, based on IETF's draft v4 - Go language.
//
// description Defines resources pooling.
// Eases referencing and avoids downloading the same resource twice.
//
// created 26-02-2013
package gojsonschema
import (
"errors"
"fmt"
"reflect"
"github.com/xeipuuv/gojsonreference"
)
type schemaPoolDocument struct {
Document interface{}
Draft *Draft
}
type schemaPool struct {
schemaPoolDocuments map[string]*schemaPoolDocument
jsonLoaderFactory JSONLoaderFactory
autoDetect *bool
}
func (p *schemaPool) parseReferences(document interface{}, ref gojsonreference.JsonReference, pooled bool) error {
var (
draft *Draft
err error
reference = ref.String()
)
// Only the root document should be added to the schema pool if pooled is true
if _, ok := p.schemaPoolDocuments[reference]; pooled && ok {
return fmt.Errorf("Reference already exists: \"%s\"", reference)
}
if *p.autoDetect {
_, draft, err = parseSchemaURL(document)
if err != nil {
return err
}
}
err = p.parseReferencesRecursive(document, ref, draft)
if pooled {
p.schemaPoolDocuments[reference] = &schemaPoolDocument{Document: document, Draft: draft}
}
return err
}
func (p *schemaPool) parseReferencesRecursive(document interface{}, ref gojsonreference.JsonReference, draft *Draft) error {
// parseReferencesRecursive parses a JSON document and resolves all $id and $ref references.
// For $ref references it takes into account the $id scope it is in and replaces
// the reference by the absolute resolved reference
// When encountering errors it fails silently. Error handling is done when the schema
// is syntactically parsed and any error encountered here should also come up there.
switch m := document.(type) {
case []interface{}:
for _, v := range m {
p.parseReferencesRecursive(v, ref, draft)
}
case map[string]interface{}:
localRef := &ref
keyID := KEY_ID_NEW
if existsMapKey(m, KEY_ID) {
keyID = KEY_ID
}
if existsMapKey(m, keyID) && isKind(m[keyID], reflect.String) {
jsonReference, err := gojsonreference.NewJsonReference(m[keyID].(string))
if err == nil {
localRef, err = ref.Inherits(jsonReference)
if err == nil {
if _, ok := p.schemaPoolDocuments[localRef.String()]; ok {
return fmt.Errorf("Reference already exists: \"%s\"", localRef.String())
}
p.schemaPoolDocuments[localRef.String()] = &schemaPoolDocument{Document: document, Draft: draft}
}
}
}
if existsMapKey(m, KEY_REF) && isKind(m[KEY_REF], reflect.String) {
jsonReference, err := gojsonreference.NewJsonReference(m[KEY_REF].(string))
if err == nil {
absoluteRef, err := localRef.Inherits(jsonReference)
if err == nil {
m[KEY_REF] = absoluteRef.String()
}
}
}
for k, v := range m {
// const and enums should be interpreted literally, so ignore them
if k == KEY_CONST || k == KEY_ENUM {
continue
}
// Something like a property or a dependency is not a valid schema, as it might describe properties named "$ref", "$id" or "const", etc
// Therefore don't treat it like a schema.
if k == KEY_PROPERTIES || k == KEY_DEPENDENCIES || k == KEY_PATTERN_PROPERTIES {
if child, ok := v.(map[string]interface{}); ok {
for _, v := range child {
p.parseReferencesRecursive(v, *localRef, draft)
}
}
} else {
p.parseReferencesRecursive(v, *localRef, draft)
}
}
}
return nil
}
func (p *schemaPool) GetDocument(reference gojsonreference.JsonReference) (*schemaPoolDocument, error) {
var (
spd *schemaPoolDocument
draft *Draft
ok bool
err error
)
if internalLogEnabled {
internalLog("Get Document ( %s )", reference.String())
}
// Create a deep copy, so we can remove the fragment part later on without altering the original
refToURL, _ := gojsonreference.NewJsonReference(reference.String())
// First check if the given fragment is a location independent identifier
// http://json-schema.org/latest/json-schema-core.html#rfc.section.8.2.3
if spd, ok = p.schemaPoolDocuments[refToURL.String()]; ok {
if internalLogEnabled {
internalLog(" From pool")
}
return spd, nil
}
// If the given reference is not a location independent identifier,
// strip the fragment and look for a document with it's base URI
refToURL.GetUrl().Fragment = ""
if cachedSpd, ok := p.schemaPoolDocuments[refToURL.String()]; ok {
document, _, err := reference.GetPointer().Get(cachedSpd.Document)
if err != nil {
return nil, err
}
if internalLogEnabled {
internalLog(" From pool")
}
spd = &schemaPoolDocument{Document: document, Draft: cachedSpd.Draft}
p.schemaPoolDocuments[reference.String()] = spd
return spd, nil
}
// It is not possible to load anything remotely that is not canonical...
if !reference.IsCanonical() {
return nil, errors.New(formatErrorDescription(
Locale.ReferenceMustBeCanonical(),
ErrorDetails{"reference": reference.String()},
))
}
jsonReferenceLoader := p.jsonLoaderFactory.New(reference.String())
document, err := jsonReferenceLoader.LoadJSON()
if err != nil {
return nil, err
}
// add the whole document to the pool for potential re-use
p.parseReferences(document, refToURL, true)
_, draft, _ = parseSchemaURL(document)
// resolve the potential fragment and also cache it
document, _, err = reference.GetPointer().Get(document)
if err != nil {
return nil, err
}
return &schemaPoolDocument{Document: document, Draft: draft}, nil
}