61 lines
1.6 KiB
Go
61 lines
1.6 KiB
Go
package jsonpath
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// pathNode is used to construct a trie of paths to be matched
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type pathNode struct {
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matchOn interface{} // string, or integer
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childNodes []pathNode
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action DecodeAction
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}
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// match climbs the trie to find a node that matches the given JSON path.
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func (n *pathNode) match(path JsonPath) *pathNode {
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var node *pathNode = n
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for _, ps := range path {
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found := false
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for i, n := range node.childNodes {
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if n.matchOn == ps {
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node = &node.childNodes[i]
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found = true
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break
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} else if _, ok := ps.(int); ok && n.matchOn == AnyIndex {
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node = &node.childNodes[i]
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found = true
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break
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}
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}
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if !found {
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return nil
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}
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}
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return node
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}
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// PathActions represents a collection of DecodeAction functions that should be called at certain path positions
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// when scanning the JSON stream. PathActions can be created once and used many times in one or more JSON streams.
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type PathActions struct {
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node pathNode
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}
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// DecodeAction handlers are called by the Decoder when scanning objects. See PathActions.Add for more detail.
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type DecodeAction func(d *Decoder) error
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// Add specifies an action to call on the Decoder when the specified path is encountered.
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func (je *PathActions) Add(action DecodeAction, path ...interface{}) {
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var node *pathNode = &je.node
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for _, ps := range path {
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found := false
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for i, n := range node.childNodes {
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if n.matchOn == ps {
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node = &node.childNodes[i]
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found = true
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break
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}
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}
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if !found {
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node.childNodes = append(node.childNodes, pathNode{matchOn: ps})
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node = &node.childNodes[len(node.childNodes)-1]
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}
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}
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node.action = action
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}
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