Put the query package into http, since it is for http only

http/query/query.go

@@ -0,0 +1,171 @@
+// Copyright 2014 The Chihaya Authors. All rights reserved.
+// Use of this source code is governed by the BSD 2-Clause license,
+// which can be found in the LICENSE file.
+
+// Package query implements a fast, simple URL Query parser.
+package query
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+// Query represents a parsed URL.Query.
+type Query struct {
+	Infohashes []string
+	Params     map[string]string
+}
+
+// New parses a raw url query.
+func New(query string) (*Query, error) {
+	var (
+		keyStart, keyEnd int
+		valStart, valEnd int
+		firstInfohash    string
+
+		onKey       = true
+		hasInfohash = false
+
+		q = &Query{
+			Infohashes: nil,
+			Params:     make(map[string]string),
+		}
+	)
+
+	for i, length := 0, len(query); i < length; i++ {
+		separator := query[i] == '&' || query[i] == ';' || query[i] == '?'
+		if separator || i == length-1 {
+			if onKey {
+				keyStart = i + 1
+				continue
+			}
+
+			if i == length-1 && !separator {
+				if query[i] == '=' {
+					continue
+				}
+				valEnd = i
+			}
+
+			keyStr, err := url.QueryUnescape(query[keyStart : keyEnd+1])
+			if err != nil {
+				return nil, err
+			}
+
+			valStr, err := url.QueryUnescape(query[valStart : valEnd+1])
+			if err != nil {
+				return nil, err
+			}
+
+			q.Params[strings.ToLower(keyStr)] = valStr
+
+			if keyStr == "info_hash" {
+				if hasInfohash {
+					// Multiple infohashes
+					if q.Infohashes == nil {
+						q.Infohashes = []string{firstInfohash}
+					}
+					q.Infohashes = append(q.Infohashes, valStr)
+				} else {
+					firstInfohash = valStr
+					hasInfohash = true
+				}
+			}
+
+			onKey = true
+			keyStart = i + 1
+
+		} else if query[i] == '=' {
+			onKey = false
+			valStart = i + 1
+		} else if onKey {
+			keyEnd = i
+		} else {
+			valEnd = i
+		}
+	}
+
+	return q, nil
+}
+
+// Uint64 is a helper to obtain a uints of any base from a Query. After being
+// called, you can safely cast the uint64 to your desired base.
+func (q *Query) Uint64(key string) (uint64, error) {
+	str, exists := q.Params[key]
+	if !exists {
+		return 0, errors.New("value does not exist for key: " + key)
+	}
+
+	val, err := strconv.ParseUint(str, 10, 64)
+	if err != nil {
+		return 0, err
+	}
+
+	return val, nil
+}
+
+// RequestedPeerCount returns the request peer count or the provided fallback.
+func (q Query) RequestedPeerCount(fallback int) int {
+	if numWantStr, exists := q.Params["numwant"]; exists {
+		numWant, err := strconv.Atoi(numWantStr)
+		if err != nil {
+			return fallback
+		}
+		return numWant
+	}
+
+	return fallback
+}
+
+// RequestedIP returns the requested IP address from a Query.
+func (q Query) RequestedIP(r *http.Request) (net.IP, error) {
+	if ipstr, ok := q.Params["ip"]; ok {
+		if ip := net.ParseIP(ipstr); ip != nil {
+			return ip, nil
+		}
+	}
+
+	if ipstr, ok := q.Params["ipv4"]; ok {
+		if ip := net.ParseIP(ipstr); ip != nil {
+			return ip, nil
+		}
+	}
+
+	if ipstr, ok := q.Params["ipv6"]; ok {
+		if ip := net.ParseIP(ipstr); ip != nil {
+			return ip, nil
+		}
+	}
+
+	if xRealIPs, ok := q.Params["x-real-ip"]; ok {
+		if ip := net.ParseIP(string(xRealIPs[0])); ip != nil {
+			return ip, nil
+		}
+	}
+
+	if r.RemoteAddr == "" {
+		if ip := net.ParseIP("127.0.0.1"); ip != nil {
+			return ip, nil
+		}
+	}
+
+	portIndex := len(r.RemoteAddr) - 1
+	for ; portIndex >= 0; portIndex-- {
+		if r.RemoteAddr[portIndex] == ':' {
+			break
+		}
+	}
+
+	if portIndex != -1 {
+		ipstr := r.RemoteAddr[0:portIndex]
+		if ip := net.ParseIP(ipstr); ip != nil {
+			return ip, nil
+		}
+	}
+
+	return nil, errors.New("failed to parse IP address")
+}