getValue() — gin Function Reference

Source Code

tree.go lines 418–665

func (n *node) getValue(path string, params *Params, skippedNodes *[]skippedNode, unescape bool) (value nodeValue) {
	var globalParamsCount int16

walk: // Outer loop for walking the tree
	for {
		prefix := n.path
		if len(path) > len(prefix) {
			if path[:len(prefix)] == prefix {
				path = path[len(prefix):]

				// Try all the non-wildcard children first by matching the indices
				idxc := path[0]
				for i, c := range []byte(n.indices) {
					if c == idxc {
						//  strings.HasPrefix(n.children[len(n.children)-1].path, ":") == n.wildChild
						if n.wildChild {
							index := len(*skippedNodes)
							*skippedNodes = (*skippedNodes)[:index+1]
							(*skippedNodes)[index] = skippedNode{
								path: prefix + path,
								node: &node{
									path:      n.path,
									wildChild: n.wildChild,
									nType:     n.nType,
									priority:  n.priority,
									children:  n.children,
									handlers:  n.handlers,
									fullPath:  n.fullPath,
								},
								paramsCount: globalParamsCount,
							}
						}

						n = n.children[i]
						continue walk
					}
				}

				if !n.wildChild {
					// If the path at the end of the loop is not equal to '/' and the current node has no child nodes
					// the current node needs to roll back to last valid skippedNode
					if path != "/" {
						for length := len(*skippedNodes); length > 0; length-- {
							skippedNode := (*skippedNodes)[length-1]
							*skippedNodes = (*skippedNodes)[:length-1]
							if strings.HasSuffix(skippedNode.path, path) {
								path = skippedNode.path
								n = skippedNode.node
								if value.params != nil {
									*value.params = (*value.params)[:skippedNode.paramsCount]
								}
								globalParamsCount = skippedNode.paramsCount
								continue walk
							}
						}
					}

					// Nothing found.
					// We can recommend to redirect to the same URL without a
					// trailing slash if a leaf exists for that path.
					value.tsr = path == "/" && n.handlers != nil
					return value
				}

				// Handle wildcard child, which is always at the end of the array
				n = n.children[len(n.children)-1]
				globalParamsCount++

				switch n.nType {
				case param:
					// fix truncate the parameter
					// tree_test.go  line: 204

					// Find param end (either '/' or path end)
					end := 0
					for end < len(path) && path[end] != '/' {
						end++
					}

					// Save param value
					if params != nil {
						// Preallocate capacity if necessary
						if cap(*params) < int(globalParamsCount) {
							newParams := make(Params, len(*params), globalParamsCount)
							copy(newParams, *params)
							*params = newParams
						}

						if value.params == nil {
							value.params = params
						}
						// Expand slice within preallocated capacity
						i := len(*value.params)
						*value.params = (*value.params)[:i+1]
						val := path[:end]
						if unescape {
							if v, err := url.QueryUnescape(val); err == nil {
								val = v
							}
						}
						(*value.params)[i] = Param{
							Key:   n.path[1:],
							Value: val,
						}
					}

					// we need to go deeper!
					if end < len(path) {
						if len(n.children) > 0 {
							path = path[end:]
							n = n.children[0]
							continue walk
						}

						// ... but we can't
						value.tsr = len(path) == end+1
						return value
					}

					if value.handlers = n.handlers; value.handlers != nil {
						value.fullPath = n.fullPath
						return value
					}
					if len(n.children) == 1 {
						// No handle found. Check if a handle for this path + a
						// trailing slash exists for TSR recommendation
						n = n.children[0]
						value.tsr = (n.path == "/" && n.handlers != nil) || (n.path == "" && n.indices == "/")
					}
					return value

				case catchAll:
					// Save param value
					if params != nil {
						// Preallocate capacity if necessary
						if cap(*params) < int(globalParamsCount) {
							newParams := make(Params, len(*params), globalParamsCount)
							copy(newParams, *params)
							*params = newParams
						}

						if value.params == nil {
							value.params = params
						}
						// Expand slice within preallocated capacity
						i := len(*value.params)
						*value.params = (*value.params)[:i+1]
						val := path
						if unescape {
							if v, err := url.QueryUnescape(path); err == nil {
								val = v
							}
						}
						(*value.params)[i] = Param{
							Key:   n.path[2:],
							Value: val,
						}
					}

					value.handlers = n.handlers
					value.fullPath = n.fullPath
					return value

				default:
					panic("invalid node type")
				}
			}
		}

		if path == prefix {
			// If the current path does not equal '/' and the node does not have a registered handle and the most recently matched node has a child node
			// the current node needs to roll back to last valid skippedNode
			if n.handlers == nil && path != "/" {
				for length := len(*skippedNodes); length > 0; length-- {
					skippedNode := (*skippedNodes)[length-1]
					*skippedNodes = (*skippedNodes)[:length-1]
					if strings.HasSuffix(skippedNode.path, path) {
						path = skippedNode.path
						n = skippedNode.node
						if value.params != nil {
							*value.params = (*value.params)[:skippedNode.paramsCount]
						}
						globalParamsCount = skippedNode.paramsCount
						continue walk
					}
				}
				//	n = latestNode.children[len(latestNode.children)-1]
			}
			// We should have reached the node containing the handle.
			// Check if this node has a handle registered.
			if value.handlers = n.handlers; value.handlers != nil {
				value.fullPath = n.fullPath
				return value
			}

			// If there is no handle for this route, but this route has a
			// wildcard child, there must be a handle for this path with an
			// additional trailing slash
			if path == "/" && n.wildChild && n.nType != root {
				value.tsr = true
				return value
			}

			if path == "/" && n.nType == static {
				value.tsr = true
				return value
			}

			// No handle found. Check if a handle for this path + a
			// trailing slash exists for trailing slash recommendation
			for i, c := range []byte(n.indices) {
				if c == '/' {
					n = n.children[i]
					value.tsr = (len(n.path) == 1 && n.handlers != nil) ||
						(n.nType == catchAll && n.children[0].handlers != nil)
					return value
				}
			}

			return value
		}

		// Nothing found. We can recommend to redirect to the same URL with an
		// extra trailing slash if a leaf exists for that path
		value.tsr = path == "/" ||
			(len(prefix) == len(path)+1 && prefix[len(path)] == '/' &&
				path == prefix[:len(prefix)-1] && n.handlers != nil)

		// roll back to last valid skippedNode
		if !value.tsr && path != "/" {
			for length := len(*skippedNodes); length > 0; length-- {
				skippedNode := (*skippedNodes)[length-1]
				*skippedNodes = (*skippedNodes)[:length-1]
				if strings.HasSuffix(skippedNode.path, path) {
					path = skippedNode.path
					n = skippedNode.node
					if value.params != nil {
						*value.params = (*value.params)[:skippedNode.paramsCount]
					}
					globalParamsCount = skippedNode.paramsCount
					continue walk
				}
			}
		}

		return value
	}
}