Implement blocking, fully compatible with rules from version 1
This commit is contained in:
Frank Denis
parent
a8ec0957e8
commit
170e2e816e
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@ -37,6 +37,12 @@
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packages = ["."]
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revision = "855e8d98f1852d48dde521e0522408d1fe7e836a"
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[[projects]]
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branch = "master"
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name = "github.com/hashicorp/go-immutable-radix"
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packages = ["."]
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revision = "59b67882ec612f43b9d4c4fd97cebd507be4b3ee"
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[[projects]]
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branch = "master"
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name = "github.com/hashicorp/golang-lru"
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@ -99,6 +105,6 @@
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[solve-meta]
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analyzer-name = "dep"
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analyzer-version = 1
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inputs-digest = "9946fe30a0b048dbe5b8a10b28e8bffd7ec6dac56380db345cbd868862fe7f08"
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inputs-digest = "01e41ba3f8bb51f155fbca27baa1f94d4bc8e8d21d094b531941d78e01945fe2"
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solver-name = "gps-cdcl"
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solver-version = 1
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@ -37,3 +37,7 @@
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[[constraint]]
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branch = "master"
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name = "golang.org/x/crypto"
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[[constraint]]
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branch = "master"
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name = "github.com/hashicorp/go-immutable-radix"
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@ -72,3 +72,11 @@ func Max(a, b int) int {
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}
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return b
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}
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func StringReverse(s string) string {
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r := []rune(s)
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for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 {
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r[i], r[j] = r[j], r[i]
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}
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return string(r)
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}
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@ -25,6 +25,7 @@ type Config struct {
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CacheMinTTL uint32 `toml:"cache_min_ttl"`
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CacheMaxTTL uint32 `toml:"cache_max_ttl"`
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QueryLog QueryLogConfig `toml:"query_log"`
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BlockName BlockNameConfig `toml:"block_name"`
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ServersConfig map[string]ServerConfig `toml:"servers"`
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SourcesConfig map[string]SourceConfig `toml:"sources"`
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}
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@ -64,6 +65,10 @@ type QueryLogConfig struct {
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Format string
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}
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type BlockNameConfig struct {
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File string
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}
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func ConfigLoad(proxy *Proxy, config_file string) error {
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configFile := flag.String("config", "dnscrypt-proxy.toml", "path to the configuration file")
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flag.Parse()
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@ -98,6 +103,7 @@ func ConfigLoad(proxy *Proxy, config_file string) error {
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}
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proxy.queryLogFile = config.QueryLog.File
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proxy.queryLogFormat = config.QueryLog.Format
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proxy.blockNameFile = config.BlockName.File
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if len(config.ServerNames) == 0 {
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for serverName := range config.ServersConfig {
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config.ServerNames = append(config.ServerNames, serverName)
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@ -54,12 +54,19 @@ block_ipv6 = false
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[query_log]
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### Full path to the query log file
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file = "/tmp/query.log"
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# file = "/tmp/query.log"
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### Query log format (currently supported: tsv and ltsv)
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format = "tsv"
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############## Pattern-based blocking ##############
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[block_name]
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## Full path to the file of blocking rules
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# file = "/tmp/mybase.txt"
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############## DNS Cache ##############
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## Enable a basic DNS cache to reduce outgoing traffic
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@ -1,6 +1,7 @@
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package main
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import (
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"strings"
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"time"
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"github.com/miekg/dns"
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@ -29,6 +30,15 @@ func EmptyResponseFromMessage(srcMsg *dns.Msg) (*dns.Msg, error) {
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return dstMsg, nil
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}
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func RefusedResponseFromMessage(srcMsg *dns.Msg) (*dns.Msg, error) {
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dstMsg, err := EmptyResponseFromMessage(srcMsg)
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if err != nil {
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return dstMsg, err
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}
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dstMsg.Rcode = dns.RcodeRefused
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return dstMsg, nil
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}
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func HasTCFlag(packet []byte) bool {
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return packet[2]&2 == 2
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}
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@ -41,6 +51,13 @@ func NormalizeName(name *[]byte) {
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}
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}
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func StripTrailingDot(str string) string {
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if strings.HasSuffix(str, ".") {
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str = str[:len(str)-1]
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}
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return str
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}
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func getMinTTL(msg *dns.Msg, minTTL uint32, maxTTL uint32, negCacheMinTTL uint32) time.Duration {
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if msg.Rcode != dns.RcodeSuccess || len(msg.Answer) <= 0 {
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return time.Duration(negCacheMinTTL) * time.Second
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@ -30,6 +30,7 @@ type Proxy struct {
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cacheMaxTTL uint32
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queryLogFile string
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queryLogFormat string
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blockNameFile string
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pluginsGlobals PluginsGlobals
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}
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@ -194,6 +195,9 @@ func (proxy *Proxy) processIncomingQuery(serverInfo *ServerInfo, clientProto str
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return
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}
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}
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if pluginsState.action == PluginsActionDrop {
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return
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}
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}
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if len(response) == 0 {
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encryptedQuery, clientNonce, err := proxy.Encrypt(serverInfo, query, serverProto)
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@ -0,0 +1,129 @@
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package main
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import (
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"io/ioutil"
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"strings"
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"github.com/hashicorp/go-immutable-radix"
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"github.com/jedisct1/dlog"
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"github.com/miekg/dns"
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)
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type PluginBlockType int
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const (
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PluginBlockTypeNone = iota
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PluginBlockTypePrefix
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PluginBlockTypeSuffix
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PluginBlockTypeSubstring
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PluginBlockTypePattern
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)
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type PluginBlockName struct {
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blockedPrefixes *iradix.Tree
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blockedSuffixes *iradix.Tree
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blockedSubstrings []string
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blockedPatterns []string
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}
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func (plugin *PluginBlockName) Name() string {
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return "block_name"
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}
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func (plugin *PluginBlockName) Description() string {
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return "Block DNS queries matching name patterns"
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}
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func (plugin *PluginBlockName) Init(proxy *Proxy) error {
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dlog.Noticef("Loading the set of blocking rules from [%s]", proxy.blockNameFile)
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bin, err := ioutil.ReadFile(proxy.blockNameFile)
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if err != nil {
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return err
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}
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plugin.blockedPrefixes = iradix.New()
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plugin.blockedSuffixes = iradix.New()
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for lineNo, line := range strings.Split(string(bin), "\n") {
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line = strings.Trim(line, " \t\r\n")
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if len(line) == 0 || strings.HasPrefix(line, "#") {
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continue
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}
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leadingStar := strings.HasPrefix(line, "*")
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trailingStar := strings.HasSuffix(line, "*")
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blockType := PluginBlockTypeNone
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if leadingStar && trailingStar {
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blockType = PluginBlockTypeSubstring
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if len(line) < 3 {
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dlog.Errorf("Syntax error in block rules at line %d", lineNo)
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continue
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}
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line = line[1 : len(line)-1]
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} else if trailingStar {
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blockType = PluginBlockTypePrefix
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if len(line) < 2 {
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dlog.Errorf("Syntax error in block rules at line %d", lineNo)
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continue
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}
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line = line[:len(line)-1]
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} else {
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blockType = PluginBlockTypeSuffix
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if leadingStar {
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line = line[1:]
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}
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if strings.HasPrefix(line, ".") {
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line = line[1:]
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}
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}
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if len(line) == 0 {
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dlog.Errorf("Syntax error in block rule at line %d", lineNo)
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continue
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}
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line = strings.ToLower(line)
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switch blockType {
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case PluginBlockTypeSubstring:
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plugin.blockedSubstrings = append(plugin.blockedSubstrings, line)
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case PluginBlockTypePrefix:
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plugin.blockedPrefixes, _, _ = plugin.blockedPrefixes.Insert([]byte(line), 0)
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case PluginBlockTypeSuffix:
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plugin.blockedSuffixes, _, _ = plugin.blockedSuffixes.Insert([]byte(StringReverse(line)), 0)
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default:
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dlog.Fatal("Unexpected block type")
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}
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}
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return nil
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}
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func (plugin *PluginBlockName) Drop() error {
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return nil
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}
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func (plugin *PluginBlockName) Reload() error {
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return nil
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}
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func (plugin *PluginBlockName) Eval(pluginsState *PluginsState, msg *dns.Msg) error {
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questions := msg.Question
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if len(questions) != 1 {
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return nil
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}
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question := strings.ToLower(StripTrailingDot(questions[0].Name))
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revQuestion := StringReverse(question)
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match, _, found := plugin.blockedSuffixes.Root().LongestPrefix([]byte(revQuestion))
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if found {
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if len(match) == len(question) || question[len(match)] == '.' {
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pluginsState.action = PluginsActionReject
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return nil
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}
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}
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_, _, found = plugin.blockedPrefixes.Root().LongestPrefix([]byte(question))
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if found {
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pluginsState.action = PluginsActionReject
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return nil
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}
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for _, substring := range plugin.blockedSubstrings {
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if strings.Contains(substring, question) {
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pluginsState.action = PluginsActionReject
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return nil
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}
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}
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return nil
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}
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@ -1,9 +1,11 @@
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package main
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import (
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"errors"
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"net"
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"sync"
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"github.com/jedisct1/dlog"
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"github.com/miekg/dns"
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)
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@ -43,6 +45,9 @@ func InitPluginsGlobals(pluginsGlobals *PluginsGlobals, proxy *Proxy) error {
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if len(proxy.queryLogFile) != 0 {
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*queryPlugins = append(*queryPlugins, Plugin(new(PluginQueryLog)))
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}
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if len(proxy.blockNameFile) != 0 {
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*queryPlugins = append(*queryPlugins, Plugin(new(PluginBlockName)))
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}
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if proxy.pluginBlockIPv6 {
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*queryPlugins = append(*queryPlugins, Plugin(new(PluginBlockIPv6)))
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}
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@ -103,6 +108,9 @@ func (pluginsState *PluginsState) ApplyQueryPlugins(pluginsGlobals *PluginsGloba
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if err := msg.Unpack(packet); err != nil {
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return packet, err
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}
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if len(msg.Question) > 1 {
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return packet, errors.New("Unexpected number of questions")
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}
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pluginsGlobals.RLock()
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for _, plugin := range *pluginsGlobals.queryPlugins {
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if ret := plugin.Eval(pluginsState, &msg); ret != nil {
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@ -110,6 +118,13 @@ func (pluginsState *PluginsState) ApplyQueryPlugins(pluginsGlobals *PluginsGloba
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pluginsState.action = PluginsActionDrop
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return packet, ret
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}
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if pluginsState.action == PluginsActionReject {
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synth, err := RefusedResponseFromMessage(&msg)
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if err != nil {
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return nil, err
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}
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pluginsState.synthResponse = synth
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}
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if pluginsState.action != PluginsActionForward {
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break
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}
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@ -138,6 +153,14 @@ func (pluginsState *PluginsState) ApplyResponsePlugins(pluginsGlobals *PluginsGl
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pluginsState.action = PluginsActionDrop
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return packet, ret
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}
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if pluginsState.action == PluginsActionReject {
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synth, err := RefusedResponseFromMessage(&msg)
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if err != nil {
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return nil, err
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}
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dlog.Infof("Blocking [%s]", synth.Question[0].Name)
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pluginsState.synthResponse = synth
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}
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if pluginsState.action != PluginsActionForward {
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break
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}
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@ -131,14 +131,14 @@ func (source *Source) Parse() ([]RegisteredServer, error) {
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if err != nil {
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return registeredServers, nil
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}
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for line, record := range records {
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for lineNo, record := range records {
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if len(record) == 0 {
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continue
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}
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if len(record) < 14 {
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return registeredServers, fmt.Errorf("Parse error at line %d", line)
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return registeredServers, fmt.Errorf("Parse error at line %d", lineNo)
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}
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if line == 0 {
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if lineNo == 0 {
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continue
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}
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name := record[0]
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@ -0,0 +1,24 @@
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# Compiled Object files, Static and Dynamic libs (Shared Objects)
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*.o
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*.a
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*.so
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# Folders
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_obj
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_test
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# Architecture specific extensions/prefixes
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*.[568vq]
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[568vq].out
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*.cgo1.go
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*.cgo2.c
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_cgo_defun.c
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_cgo_gotypes.go
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_cgo_export.*
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_testmain.go
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*.exe
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*.test
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*.prof
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@ -0,0 +1,3 @@
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language: go
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go:
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- tip
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@ -0,0 +1,363 @@
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Mozilla Public License, version 2.0
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1. Definitions
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1.1. "Contributor"
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|
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means each individual or legal entity that creates, contributes to the
|
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creation of, or owns Covered Software.
|
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1.2. "Contributor Version"
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means the combination of the Contributions of others (if any) used by a
|
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Contributor and that particular Contributor's Contribution.
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1.3. "Contribution"
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|
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means Covered Software of a particular Contributor.
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|
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1.4. "Covered Software"
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|
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means Source Code Form to which the initial Contributor has attached the
|
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notice in Exhibit A, the Executable Form of such Source Code Form, and
|
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Modifications of such Source Code Form, in each case including portions
|
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thereof.
|
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|
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1.5. "Incompatible With Secondary Licenses"
|
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means
|
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|
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a. that the initial Contributor has attached the notice described in
|
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Exhibit B to the Covered Software; or
|
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|
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b. that the Covered Software was made available under the terms of
|
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version 1.1 or earlier of the License, but not also under the terms of
|
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a Secondary License.
|
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|
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1.6. "Executable Form"
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|
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means any form of the work other than Source Code Form.
|
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|
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1.7. "Larger Work"
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|
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means a work that combines Covered Software with other material, in a
|
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separate file or files, that is not Covered Software.
|
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|
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1.8. "License"
|
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|
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means this document.
|
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|
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1.9. "Licensable"
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|
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means having the right to grant, to the maximum extent possible, whether
|
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at the time of the initial grant or subsequently, any and all of the
|
||||
rights conveyed by this License.
|
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|
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1.10. "Modifications"
|
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|
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means any of the following:
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|
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a. any file in Source Code Form that results from an addition to,
|
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deletion from, or modification of the contents of Covered Software; or
|
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|
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b. any new file in Source Code Form that contains any Covered Software.
|
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|
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1.11. "Patent Claims" of a Contributor
|
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|
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means any patent claim(s), including without limitation, method,
|
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process, and apparatus claims, in any patent Licensable by such
|
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Contributor that would be infringed, but for the grant of the License,
|
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by the making, using, selling, offering for sale, having made, import,
|
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or transfer of either its Contributions or its Contributor Version.
|
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|
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1.12. "Secondary License"
|
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|
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means either the GNU General Public License, Version 2.0, the GNU Lesser
|
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General Public License, Version 2.1, the GNU Affero General Public
|
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License, Version 3.0, or any later versions of those licenses.
|
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|
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1.13. "Source Code Form"
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|
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means the form of the work preferred for making modifications.
|
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|
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1.14. "You" (or "Your")
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|
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means an individual or a legal entity exercising rights under this
|
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License. For legal entities, "You" includes any entity that controls, is
|
||||
controlled by, or is under common control with You. For purposes of this
|
||||
definition, "control" means (a) the power, direct or indirect, to cause
|
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the direction or management of such entity, whether by contract or
|
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otherwise, or (b) ownership of more than fifty percent (50%) of the
|
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outstanding shares or beneficial ownership of such entity.
|
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|
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|
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2. License Grants and Conditions
|
||||
|
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2.1. Grants
|
||||
|
||||
Each Contributor hereby grants You a world-wide, royalty-free,
|
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non-exclusive license:
|
||||
|
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a. under intellectual property rights (other than patent or trademark)
|
||||
Licensable by such Contributor to use, reproduce, make available,
|
||||
modify, display, perform, distribute, and otherwise exploit its
|
||||
Contributions, either on an unmodified basis, with Modifications, or
|
||||
as part of a Larger Work; and
|
||||
|
||||
b. under Patent Claims of such Contributor to make, use, sell, offer for
|
||||
sale, have made, import, and otherwise transfer either its
|
||||
Contributions or its Contributor Version.
|
||||
|
||||
2.2. Effective Date
|
||||
|
||||
The licenses granted in Section 2.1 with respect to any Contribution
|
||||
become effective for each Contribution on the date the Contributor first
|
||||
distributes such Contribution.
|
||||
|
||||
2.3. Limitations on Grant Scope
|
||||
|
||||
The licenses granted in this Section 2 are the only rights granted under
|
||||
this License. No additional rights or licenses will be implied from the
|
||||
distribution or licensing of Covered Software under this License.
|
||||
Notwithstanding Section 2.1(b) above, no patent license is granted by a
|
||||
Contributor:
|
||||
|
||||
a. for any code that a Contributor has removed from Covered Software; or
|
||||
|
||||
b. for infringements caused by: (i) Your and any other third party's
|
||||
modifications of Covered Software, or (ii) the combination of its
|
||||
Contributions with other software (except as part of its Contributor
|
||||
Version); or
|
||||
|
||||
c. under Patent Claims infringed by Covered Software in the absence of
|
||||
its Contributions.
|
||||
|
||||
This License does not grant any rights in the trademarks, service marks,
|
||||
or logos of any Contributor (except as may be necessary to comply with
|
||||
the notice requirements in Section 3.4).
|
||||
|
||||
2.4. Subsequent Licenses
|
||||
|
||||
No Contributor makes additional grants as a result of Your choice to
|
||||
distribute the Covered Software under a subsequent version of this
|
||||
License (see Section 10.2) or under the terms of a Secondary License (if
|
||||
permitted under the terms of Section 3.3).
|
||||
|
||||
2.5. Representation
|
||||
|
||||
Each Contributor represents that the Contributor believes its
|
||||
Contributions are its original creation(s) or it has sufficient rights to
|
||||
grant the rights to its Contributions conveyed by this License.
|
||||
|
||||
2.6. Fair Use
|
||||
|
||||
This License is not intended to limit any rights You have under
|
||||
applicable copyright doctrines of fair use, fair dealing, or other
|
||||
equivalents.
|
||||
|
||||
2.7. Conditions
|
||||
|
||||
Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
|
||||
Section 2.1.
|
||||
|
||||
|
||||
3. Responsibilities
|
||||
|
||||
3.1. Distribution of Source Form
|
||||
|
||||
All distribution of Covered Software in Source Code Form, including any
|
||||
Modifications that You create or to which You contribute, must be under
|
||||
the terms of this License. You must inform recipients that the Source
|
||||
Code Form of the Covered Software is governed by the terms of this
|
||||
License, and how they can obtain a copy of this License. You may not
|
||||
attempt to alter or restrict the recipients' rights in the Source Code
|
||||
Form.
|
||||
|
||||
3.2. Distribution of Executable Form
|
||||
|
||||
If You distribute Covered Software in Executable Form then:
|
||||
|
||||
a. such Covered Software must also be made available in Source Code Form,
|
||||
as described in Section 3.1, and You must inform recipients of the
|
||||
Executable Form how they can obtain a copy of such Source Code Form by
|
||||
reasonable means in a timely manner, at a charge no more than the cost
|
||||
of distribution to the recipient; and
|
||||
|
||||
b. You may distribute such Executable Form under the terms of this
|
||||
License, or sublicense it under different terms, provided that the
|
||||
license for the Executable Form does not attempt to limit or alter the
|
||||
recipients' rights in the Source Code Form under this License.
|
||||
|
||||
3.3. Distribution of a Larger Work
|
||||
|
||||
You may create and distribute a Larger Work under terms of Your choice,
|
||||
provided that You also comply with the requirements of this License for
|
||||
the Covered Software. If the Larger Work is a combination of Covered
|
||||
Software with a work governed by one or more Secondary Licenses, and the
|
||||
Covered Software is not Incompatible With Secondary Licenses, this
|
||||
License permits You to additionally distribute such Covered Software
|
||||
under the terms of such Secondary License(s), so that the recipient of
|
||||
the Larger Work may, at their option, further distribute the Covered
|
||||
Software under the terms of either this License or such Secondary
|
||||
License(s).
|
||||
|
||||
3.4. Notices
|
||||
|
||||
You may not remove or alter the substance of any license notices
|
||||
(including copyright notices, patent notices, disclaimers of warranty, or
|
||||
limitations of liability) contained within the Source Code Form of the
|
||||
Covered Software, except that You may alter any license notices to the
|
||||
extent required to remedy known factual inaccuracies.
|
||||
|
||||
3.5. Application of Additional Terms
|
||||
|
||||
You may choose to offer, and to charge a fee for, warranty, support,
|
||||
indemnity or liability obligations to one or more recipients of Covered
|
||||
Software. However, You may do so only on Your own behalf, and not on
|
||||
behalf of any Contributor. You must make it absolutely clear that any
|
||||
such warranty, support, indemnity, or liability obligation is offered by
|
||||
You alone, and You hereby agree to indemnify every Contributor for any
|
||||
liability incurred by such Contributor as a result of warranty, support,
|
||||
indemnity or liability terms You offer. You may include additional
|
||||
disclaimers of warranty and limitations of liability specific to any
|
||||
jurisdiction.
|
||||
|
||||
4. Inability to Comply Due to Statute or Regulation
|
||||
|
||||
If it is impossible for You to comply with any of the terms of this License
|
||||
with respect to some or all of the Covered Software due to statute,
|
||||
judicial order, or regulation then You must: (a) comply with the terms of
|
||||
this License to the maximum extent possible; and (b) describe the
|
||||
limitations and the code they affect. Such description must be placed in a
|
||||
text file included with all distributions of the Covered Software under
|
||||
this License. Except to the extent prohibited by statute or regulation,
|
||||
such description must be sufficiently detailed for a recipient of ordinary
|
||||
skill to be able to understand it.
|
||||
|
||||
5. Termination
|
||||
|
||||
5.1. The rights granted under this License will terminate automatically if You
|
||||
fail to comply with any of its terms. However, if You become compliant,
|
||||
then the rights granted under this License from a particular Contributor
|
||||
are reinstated (a) provisionally, unless and until such Contributor
|
||||
explicitly and finally terminates Your grants, and (b) on an ongoing
|
||||
basis, if such Contributor fails to notify You of the non-compliance by
|
||||
some reasonable means prior to 60 days after You have come back into
|
||||
compliance. Moreover, Your grants from a particular Contributor are
|
||||
reinstated on an ongoing basis if such Contributor notifies You of the
|
||||
non-compliance by some reasonable means, this is the first time You have
|
||||
received notice of non-compliance with this License from such
|
||||
Contributor, and You become compliant prior to 30 days after Your receipt
|
||||
of the notice.
|
||||
|
||||
5.2. If You initiate litigation against any entity by asserting a patent
|
||||
infringement claim (excluding declaratory judgment actions,
|
||||
counter-claims, and cross-claims) alleging that a Contributor Version
|
||||
directly or indirectly infringes any patent, then the rights granted to
|
||||
You by any and all Contributors for the Covered Software under Section
|
||||
2.1 of this License shall terminate.
|
||||
|
||||
5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
|
||||
license agreements (excluding distributors and resellers) which have been
|
||||
validly granted by You or Your distributors under this License prior to
|
||||
termination shall survive termination.
|
||||
|
||||
6. Disclaimer of Warranty
|
||||
|
||||
Covered Software is provided under this License on an "as is" basis,
|
||||
without warranty of any kind, either expressed, implied, or statutory,
|
||||
including, without limitation, warranties that the Covered Software is free
|
||||
of defects, merchantable, fit for a particular purpose or non-infringing.
|
||||
The entire risk as to the quality and performance of the Covered Software
|
||||
is with You. Should any Covered Software prove defective in any respect,
|
||||
You (not any Contributor) assume the cost of any necessary servicing,
|
||||
repair, or correction. This disclaimer of warranty constitutes an essential
|
||||
part of this License. No use of any Covered Software is authorized under
|
||||
this License except under this disclaimer.
|
||||
|
||||
7. Limitation of Liability
|
||||
|
||||
Under no circumstances and under no legal theory, whether tort (including
|
||||
negligence), contract, or otherwise, shall any Contributor, or anyone who
|
||||
distributes Covered Software as permitted above, be liable to You for any
|
||||
direct, indirect, special, incidental, or consequential damages of any
|
||||
character including, without limitation, damages for lost profits, loss of
|
||||
goodwill, work stoppage, computer failure or malfunction, or any and all
|
||||
other commercial damages or losses, even if such party shall have been
|
||||
informed of the possibility of such damages. This limitation of liability
|
||||
shall not apply to liability for death or personal injury resulting from
|
||||
such party's negligence to the extent applicable law prohibits such
|
||||
limitation. Some jurisdictions do not allow the exclusion or limitation of
|
||||
incidental or consequential damages, so this exclusion and limitation may
|
||||
not apply to You.
|
||||
|
||||
8. Litigation
|
||||
|
||||
Any litigation relating to this License may be brought only in the courts
|
||||
of a jurisdiction where the defendant maintains its principal place of
|
||||
business and such litigation shall be governed by laws of that
|
||||
jurisdiction, without reference to its conflict-of-law provisions. Nothing
|
||||
in this Section shall prevent a party's ability to bring cross-claims or
|
||||
counter-claims.
|
||||
|
||||
9. Miscellaneous
|
||||
|
||||
This License represents the complete agreement concerning the subject
|
||||
matter hereof. If any provision of this License is held to be
|
||||
unenforceable, such provision shall be reformed only to the extent
|
||||
necessary to make it enforceable. Any law or regulation which provides that
|
||||
the language of a contract shall be construed against the drafter shall not
|
||||
be used to construe this License against a Contributor.
|
||||
|
||||
|
||||
10. Versions of the License
|
||||
|
||||
10.1. New Versions
|
||||
|
||||
Mozilla Foundation is the license steward. Except as provided in Section
|
||||
10.3, no one other than the license steward has the right to modify or
|
||||
publish new versions of this License. Each version will be given a
|
||||
distinguishing version number.
|
||||
|
||||
10.2. Effect of New Versions
|
||||
|
||||
You may distribute the Covered Software under the terms of the version
|
||||
of the License under which You originally received the Covered Software,
|
||||
or under the terms of any subsequent version published by the license
|
||||
steward.
|
||||
|
||||
10.3. Modified Versions
|
||||
|
||||
If you create software not governed by this License, and you want to
|
||||
create a new license for such software, you may create and use a
|
||||
modified version of this License if you rename the license and remove
|
||||
any references to the name of the license steward (except to note that
|
||||
such modified license differs from this License).
|
||||
|
||||
10.4. Distributing Source Code Form that is Incompatible With Secondary
|
||||
Licenses If You choose to distribute Source Code Form that is
|
||||
Incompatible With Secondary Licenses under the terms of this version of
|
||||
the License, the notice described in Exhibit B of this License must be
|
||||
attached.
|
||||
|
||||
Exhibit A - Source Code Form License Notice
|
||||
|
||||
This Source Code Form is subject to the
|
||||
terms of the Mozilla Public License, v.
|
||||
2.0. If a copy of the MPL was not
|
||||
distributed with this file, You can
|
||||
obtain one at
|
||||
http://mozilla.org/MPL/2.0/.
|
||||
|
||||
If it is not possible or desirable to put the notice in a particular file,
|
||||
then You may include the notice in a location (such as a LICENSE file in a
|
||||
relevant directory) where a recipient would be likely to look for such a
|
||||
notice.
|
||||
|
||||
You may add additional accurate notices of copyright ownership.
|
||||
|
||||
Exhibit B - "Incompatible With Secondary Licenses" Notice
|
||||
|
||||
This Source Code Form is "Incompatible
|
||||
With Secondary Licenses", as defined by
|
||||
the Mozilla Public License, v. 2.0.
|
||||
|
||||
|
|
@ -0,0 +1,41 @@
|
|||
go-immutable-radix [](https://travis-ci.org/hashicorp/go-immutable-radix)
|
||||
=========
|
||||
|
||||
Provides the `iradix` package that implements an immutable [radix tree](http://en.wikipedia.org/wiki/Radix_tree).
|
||||
The package only provides a single `Tree` implementation, optimized for sparse nodes.
|
||||
|
||||
As a radix tree, it provides the following:
|
||||
* O(k) operations. In many cases, this can be faster than a hash table since
|
||||
the hash function is an O(k) operation, and hash tables have very poor cache locality.
|
||||
* Minimum / Maximum value lookups
|
||||
* Ordered iteration
|
||||
|
||||
A tree supports using a transaction to batch multiple updates (insert, delete)
|
||||
in a more efficient manner than performing each operation one at a time.
|
||||
|
||||
For a mutable variant, see [go-radix](https://github.com/armon/go-radix).
|
||||
|
||||
Documentation
|
||||
=============
|
||||
|
||||
The full documentation is available on [Godoc](http://godoc.org/github.com/hashicorp/go-immutable-radix).
|
||||
|
||||
Example
|
||||
=======
|
||||
|
||||
Below is a simple example of usage
|
||||
|
||||
```go
|
||||
// Create a tree
|
||||
r := iradix.New()
|
||||
r, _, _ = r.Insert([]byte("foo"), 1)
|
||||
r, _, _ = r.Insert([]byte("bar"), 2)
|
||||
r, _, _ = r.Insert([]byte("foobar"), 2)
|
||||
|
||||
// Find the longest prefix match
|
||||
m, _, _ := r.Root().LongestPrefix([]byte("foozip"))
|
||||
if string(m) != "foo" {
|
||||
panic("should be foo")
|
||||
}
|
||||
```
|
||||
|
||||
|
|
@ -0,0 +1,21 @@
|
|||
package iradix
|
||||
|
||||
import "sort"
|
||||
|
||||
type edges []edge
|
||||
|
||||
func (e edges) Len() int {
|
||||
return len(e)
|
||||
}
|
||||
|
||||
func (e edges) Less(i, j int) bool {
|
||||
return e[i].label < e[j].label
|
||||
}
|
||||
|
||||
func (e edges) Swap(i, j int) {
|
||||
e[i], e[j] = e[j], e[i]
|
||||
}
|
||||
|
||||
func (e edges) Sort() {
|
||||
sort.Sort(e)
|
||||
}
|
||||
|
|
@ -0,0 +1,657 @@
|
|||
package iradix
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"strings"
|
||||
|
||||
"github.com/hashicorp/golang-lru/simplelru"
|
||||
)
|
||||
|
||||
const (
|
||||
// defaultModifiedCache is the default size of the modified node
|
||||
// cache used per transaction. This is used to cache the updates
|
||||
// to the nodes near the root, while the leaves do not need to be
|
||||
// cached. This is important for very large transactions to prevent
|
||||
// the modified cache from growing to be enormous. This is also used
|
||||
// to set the max size of the mutation notify maps since those should
|
||||
// also be bounded in a similar way.
|
||||
defaultModifiedCache = 8192
|
||||
)
|
||||
|
||||
// Tree implements an immutable radix tree. This can be treated as a
|
||||
// Dictionary abstract data type. The main advantage over a standard
|
||||
// hash map is prefix-based lookups and ordered iteration. The immutability
|
||||
// means that it is safe to concurrently read from a Tree without any
|
||||
// coordination.
|
||||
type Tree struct {
|
||||
root *Node
|
||||
size int
|
||||
}
|
||||
|
||||
// New returns an empty Tree
|
||||
func New() *Tree {
|
||||
t := &Tree{
|
||||
root: &Node{
|
||||
mutateCh: make(chan struct{}),
|
||||
},
|
||||
}
|
||||
return t
|
||||
}
|
||||
|
||||
// Len is used to return the number of elements in the tree
|
||||
func (t *Tree) Len() int {
|
||||
return t.size
|
||||
}
|
||||
|
||||
// Txn is a transaction on the tree. This transaction is applied
|
||||
// atomically and returns a new tree when committed. A transaction
|
||||
// is not thread safe, and should only be used by a single goroutine.
|
||||
type Txn struct {
|
||||
// root is the modified root for the transaction.
|
||||
root *Node
|
||||
|
||||
// snap is a snapshot of the root node for use if we have to run the
|
||||
// slow notify algorithm.
|
||||
snap *Node
|
||||
|
||||
// size tracks the size of the tree as it is modified during the
|
||||
// transaction.
|
||||
size int
|
||||
|
||||
// writable is a cache of writable nodes that have been created during
|
||||
// the course of the transaction. This allows us to re-use the same
|
||||
// nodes for further writes and avoid unnecessary copies of nodes that
|
||||
// have never been exposed outside the transaction. This will only hold
|
||||
// up to defaultModifiedCache number of entries.
|
||||
writable *simplelru.LRU
|
||||
|
||||
// trackChannels is used to hold channels that need to be notified to
|
||||
// signal mutation of the tree. This will only hold up to
|
||||
// defaultModifiedCache number of entries, after which we will set the
|
||||
// trackOverflow flag, which will cause us to use a more expensive
|
||||
// algorithm to perform the notifications. Mutation tracking is only
|
||||
// performed if trackMutate is true.
|
||||
trackChannels map[chan struct{}]struct{}
|
||||
trackOverflow bool
|
||||
trackMutate bool
|
||||
}
|
||||
|
||||
// Txn starts a new transaction that can be used to mutate the tree
|
||||
func (t *Tree) Txn() *Txn {
|
||||
txn := &Txn{
|
||||
root: t.root,
|
||||
snap: t.root,
|
||||
size: t.size,
|
||||
}
|
||||
return txn
|
||||
}
|
||||
|
||||
// TrackMutate can be used to toggle if mutations are tracked. If this is enabled
|
||||
// then notifications will be issued for affected internal nodes and leaves when
|
||||
// the transaction is committed.
|
||||
func (t *Txn) TrackMutate(track bool) {
|
||||
t.trackMutate = track
|
||||
}
|
||||
|
||||
// trackChannel safely attempts to track the given mutation channel, setting the
|
||||
// overflow flag if we can no longer track any more. This limits the amount of
|
||||
// state that will accumulate during a transaction and we have a slower algorithm
|
||||
// to switch to if we overflow.
|
||||
func (t *Txn) trackChannel(ch chan struct{}) {
|
||||
// In overflow, make sure we don't store any more objects.
|
||||
if t.trackOverflow {
|
||||
return
|
||||
}
|
||||
|
||||
// If this would overflow the state we reject it and set the flag (since
|
||||
// we aren't tracking everything that's required any longer).
|
||||
if len(t.trackChannels) >= defaultModifiedCache {
|
||||
// Mark that we are in the overflow state
|
||||
t.trackOverflow = true
|
||||
|
||||
// Clear the map so that the channels can be garbage collected. It is
|
||||
// safe to do this since we have already overflowed and will be using
|
||||
// the slow notify algorithm.
|
||||
t.trackChannels = nil
|
||||
return
|
||||
}
|
||||
|
||||
// Create the map on the fly when we need it.
|
||||
if t.trackChannels == nil {
|
||||
t.trackChannels = make(map[chan struct{}]struct{})
|
||||
}
|
||||
|
||||
// Otherwise we are good to track it.
|
||||
t.trackChannels[ch] = struct{}{}
|
||||
}
|
||||
|
||||
// writeNode returns a node to be modified, if the current node has already been
|
||||
// modified during the course of the transaction, it is used in-place. Set
|
||||
// forLeafUpdate to true if you are getting a write node to update the leaf,
|
||||
// which will set leaf mutation tracking appropriately as well.
|
||||
func (t *Txn) writeNode(n *Node, forLeafUpdate bool) *Node {
|
||||
// Ensure the writable set exists.
|
||||
if t.writable == nil {
|
||||
lru, err := simplelru.NewLRU(defaultModifiedCache, nil)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
t.writable = lru
|
||||
}
|
||||
|
||||
// If this node has already been modified, we can continue to use it
|
||||
// during this transaction. We know that we don't need to track it for
|
||||
// a node update since the node is writable, but if this is for a leaf
|
||||
// update we track it, in case the initial write to this node didn't
|
||||
// update the leaf.
|
||||
if _, ok := t.writable.Get(n); ok {
|
||||
if t.trackMutate && forLeafUpdate && n.leaf != nil {
|
||||
t.trackChannel(n.leaf.mutateCh)
|
||||
}
|
||||
return n
|
||||
}
|
||||
|
||||
// Mark this node as being mutated.
|
||||
if t.trackMutate {
|
||||
t.trackChannel(n.mutateCh)
|
||||
}
|
||||
|
||||
// Mark its leaf as being mutated, if appropriate.
|
||||
if t.trackMutate && forLeafUpdate && n.leaf != nil {
|
||||
t.trackChannel(n.leaf.mutateCh)
|
||||
}
|
||||
|
||||
// Copy the existing node. If you have set forLeafUpdate it will be
|
||||
// safe to replace this leaf with another after you get your node for
|
||||
// writing. You MUST replace it, because the channel associated with
|
||||
// this leaf will be closed when this transaction is committed.
|
||||
nc := &Node{
|
||||
mutateCh: make(chan struct{}),
|
||||
leaf: n.leaf,
|
||||
}
|
||||
if n.prefix != nil {
|
||||
nc.prefix = make([]byte, len(n.prefix))
|
||||
copy(nc.prefix, n.prefix)
|
||||
}
|
||||
if len(n.edges) != 0 {
|
||||
nc.edges = make([]edge, len(n.edges))
|
||||
copy(nc.edges, n.edges)
|
||||
}
|
||||
|
||||
// Mark this node as writable.
|
||||
t.writable.Add(nc, nil)
|
||||
return nc
|
||||
}
|
||||
|
||||
// Visit all the nodes in the tree under n, and add their mutateChannels to the transaction
|
||||
// Returns the size of the subtree visited
|
||||
func (t *Txn) trackChannelsAndCount(n *Node) int {
|
||||
// Count only leaf nodes
|
||||
leaves := 0
|
||||
if n.leaf != nil {
|
||||
leaves = 1
|
||||
}
|
||||
// Mark this node as being mutated.
|
||||
if t.trackMutate {
|
||||
t.trackChannel(n.mutateCh)
|
||||
}
|
||||
|
||||
// Mark its leaf as being mutated, if appropriate.
|
||||
if t.trackMutate && n.leaf != nil {
|
||||
t.trackChannel(n.leaf.mutateCh)
|
||||
}
|
||||
|
||||
// Recurse on the children
|
||||
for _, e := range n.edges {
|
||||
leaves += t.trackChannelsAndCount(e.node)
|
||||
}
|
||||
return leaves
|
||||
}
|
||||
|
||||
// mergeChild is called to collapse the given node with its child. This is only
|
||||
// called when the given node is not a leaf and has a single edge.
|
||||
func (t *Txn) mergeChild(n *Node) {
|
||||
// Mark the child node as being mutated since we are about to abandon
|
||||
// it. We don't need to mark the leaf since we are retaining it if it
|
||||
// is there.
|
||||
e := n.edges[0]
|
||||
child := e.node
|
||||
if t.trackMutate {
|
||||
t.trackChannel(child.mutateCh)
|
||||
}
|
||||
|
||||
// Merge the nodes.
|
||||
n.prefix = concat(n.prefix, child.prefix)
|
||||
n.leaf = child.leaf
|
||||
if len(child.edges) != 0 {
|
||||
n.edges = make([]edge, len(child.edges))
|
||||
copy(n.edges, child.edges)
|
||||
} else {
|
||||
n.edges = nil
|
||||
}
|
||||
}
|
||||
|
||||
// insert does a recursive insertion
|
||||
func (t *Txn) insert(n *Node, k, search []byte, v interface{}) (*Node, interface{}, bool) {
|
||||
// Handle key exhaustion
|
||||
if len(search) == 0 {
|
||||
var oldVal interface{}
|
||||
didUpdate := false
|
||||
if n.isLeaf() {
|
||||
oldVal = n.leaf.val
|
||||
didUpdate = true
|
||||
}
|
||||
|
||||
nc := t.writeNode(n, true)
|
||||
nc.leaf = &leafNode{
|
||||
mutateCh: make(chan struct{}),
|
||||
key: k,
|
||||
val: v,
|
||||
}
|
||||
return nc, oldVal, didUpdate
|
||||
}
|
||||
|
||||
// Look for the edge
|
||||
idx, child := n.getEdge(search[0])
|
||||
|
||||
// No edge, create one
|
||||
if child == nil {
|
||||
e := edge{
|
||||
label: search[0],
|
||||
node: &Node{
|
||||
mutateCh: make(chan struct{}),
|
||||
leaf: &leafNode{
|
||||
mutateCh: make(chan struct{}),
|
||||
key: k,
|
||||
val: v,
|
||||
},
|
||||
prefix: search,
|
||||
},
|
||||
}
|
||||
nc := t.writeNode(n, false)
|
||||
nc.addEdge(e)
|
||||
return nc, nil, false
|
||||
}
|
||||
|
||||
// Determine longest prefix of the search key on match
|
||||
commonPrefix := longestPrefix(search, child.prefix)
|
||||
if commonPrefix == len(child.prefix) {
|
||||
search = search[commonPrefix:]
|
||||
newChild, oldVal, didUpdate := t.insert(child, k, search, v)
|
||||
if newChild != nil {
|
||||
nc := t.writeNode(n, false)
|
||||
nc.edges[idx].node = newChild
|
||||
return nc, oldVal, didUpdate
|
||||
}
|
||||
return nil, oldVal, didUpdate
|
||||
}
|
||||
|
||||
// Split the node
|
||||
nc := t.writeNode(n, false)
|
||||
splitNode := &Node{
|
||||
mutateCh: make(chan struct{}),
|
||||
prefix: search[:commonPrefix],
|
||||
}
|
||||
nc.replaceEdge(edge{
|
||||
label: search[0],
|
||||
node: splitNode,
|
||||
})
|
||||
|
||||
// Restore the existing child node
|
||||
modChild := t.writeNode(child, false)
|
||||
splitNode.addEdge(edge{
|
||||
label: modChild.prefix[commonPrefix],
|
||||
node: modChild,
|
||||
})
|
||||
modChild.prefix = modChild.prefix[commonPrefix:]
|
||||
|
||||
// Create a new leaf node
|
||||
leaf := &leafNode{
|
||||
mutateCh: make(chan struct{}),
|
||||
key: k,
|
||||
val: v,
|
||||
}
|
||||
|
||||
// If the new key is a subset, add to to this node
|
||||
search = search[commonPrefix:]
|
||||
if len(search) == 0 {
|
||||
splitNode.leaf = leaf
|
||||
return nc, nil, false
|
||||
}
|
||||
|
||||
// Create a new edge for the node
|
||||
splitNode.addEdge(edge{
|
||||
label: search[0],
|
||||
node: &Node{
|
||||
mutateCh: make(chan struct{}),
|
||||
leaf: leaf,
|
||||
prefix: search,
|
||||
},
|
||||
})
|
||||
return nc, nil, false
|
||||
}
|
||||
|
||||
// delete does a recursive deletion
|
||||
func (t *Txn) delete(parent, n *Node, search []byte) (*Node, *leafNode) {
|
||||
// Check for key exhaustion
|
||||
if len(search) == 0 {
|
||||
if !n.isLeaf() {
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
// Remove the leaf node
|
||||
nc := t.writeNode(n, true)
|
||||
nc.leaf = nil
|
||||
|
||||
// Check if this node should be merged
|
||||
if n != t.root && len(nc.edges) == 1 {
|
||||
t.mergeChild(nc)
|
||||
}
|
||||
return nc, n.leaf
|
||||
}
|
||||
|
||||
// Look for an edge
|
||||
label := search[0]
|
||||
idx, child := n.getEdge(label)
|
||||
if child == nil || !bytes.HasPrefix(search, child.prefix) {
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
// Consume the search prefix
|
||||
search = search[len(child.prefix):]
|
||||
newChild, leaf := t.delete(n, child, search)
|
||||
if newChild == nil {
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
// Copy this node. WATCH OUT - it's safe to pass "false" here because we
|
||||
// will only ADD a leaf via nc.mergeChild() if there isn't one due to
|
||||
// the !nc.isLeaf() check in the logic just below. This is pretty subtle,
|
||||
// so be careful if you change any of the logic here.
|
||||
nc := t.writeNode(n, false)
|
||||
|
||||
// Delete the edge if the node has no edges
|
||||
if newChild.leaf == nil && len(newChild.edges) == 0 {
|
||||
nc.delEdge(label)
|
||||
if n != t.root && len(nc.edges) == 1 && !nc.isLeaf() {
|
||||
t.mergeChild(nc)
|
||||
}
|
||||
} else {
|
||||
nc.edges[idx].node = newChild
|
||||
}
|
||||
return nc, leaf
|
||||
}
|
||||
|
||||
// delete does a recursive deletion
|
||||
func (t *Txn) deletePrefix(parent, n *Node, search []byte) (*Node, int) {
|
||||
// Check for key exhaustion
|
||||
if len(search) == 0 {
|
||||
nc := t.writeNode(n, true)
|
||||
if n.isLeaf() {
|
||||
nc.leaf = nil
|
||||
}
|
||||
nc.edges = nil
|
||||
return nc, t.trackChannelsAndCount(n)
|
||||
}
|
||||
|
||||
// Look for an edge
|
||||
label := search[0]
|
||||
idx, child := n.getEdge(label)
|
||||
// We make sure that either the child node's prefix starts with the search term, or the search term starts with the child node's prefix
|
||||
// Need to do both so that we can delete prefixes that don't correspond to any node in the tree
|
||||
if child == nil || (!bytes.HasPrefix(child.prefix, search) && !bytes.HasPrefix(search, child.prefix)) {
|
||||
return nil, 0
|
||||
}
|
||||
|
||||
// Consume the search prefix
|
||||
if len(child.prefix) > len(search) {
|
||||
search = []byte("")
|
||||
} else {
|
||||
search = search[len(child.prefix):]
|
||||
}
|
||||
newChild, numDeletions := t.deletePrefix(n, child, search)
|
||||
if newChild == nil {
|
||||
return nil, 0
|
||||
}
|
||||
// Copy this node. WATCH OUT - it's safe to pass "false" here because we
|
||||
// will only ADD a leaf via nc.mergeChild() if there isn't one due to
|
||||
// the !nc.isLeaf() check in the logic just below. This is pretty subtle,
|
||||
// so be careful if you change any of the logic here.
|
||||
|
||||
nc := t.writeNode(n, false)
|
||||
|
||||
// Delete the edge if the node has no edges
|
||||
if newChild.leaf == nil && len(newChild.edges) == 0 {
|
||||
nc.delEdge(label)
|
||||
if n != t.root && len(nc.edges) == 1 && !nc.isLeaf() {
|
||||
t.mergeChild(nc)
|
||||
}
|
||||
} else {
|
||||
nc.edges[idx].node = newChild
|
||||
}
|
||||
return nc, numDeletions
|
||||
}
|
||||
|
||||
// Insert is used to add or update a given key. The return provides
|
||||
// the previous value and a bool indicating if any was set.
|
||||
func (t *Txn) Insert(k []byte, v interface{}) (interface{}, bool) {
|
||||
newRoot, oldVal, didUpdate := t.insert(t.root, k, k, v)
|
||||
if newRoot != nil {
|
||||
t.root = newRoot
|
||||
}
|
||||
if !didUpdate {
|
||||
t.size++
|
||||
}
|
||||
return oldVal, didUpdate
|
||||
}
|
||||
|
||||
// Delete is used to delete a given key. Returns the old value if any,
|
||||
// and a bool indicating if the key was set.
|
||||
func (t *Txn) Delete(k []byte) (interface{}, bool) {
|
||||
newRoot, leaf := t.delete(nil, t.root, k)
|
||||
if newRoot != nil {
|
||||
t.root = newRoot
|
||||
}
|
||||
if leaf != nil {
|
||||
t.size--
|
||||
return leaf.val, true
|
||||
}
|
||||
return nil, false
|
||||
}
|
||||
|
||||
// DeletePrefix is used to delete an entire subtree that matches the prefix
|
||||
// This will delete all nodes under that prefix
|
||||
func (t *Txn) DeletePrefix(prefix []byte) bool {
|
||||
newRoot, numDeletions := t.deletePrefix(nil, t.root, prefix)
|
||||
if newRoot != nil {
|
||||
t.root = newRoot
|
||||
t.size = t.size - numDeletions
|
||||
return true
|
||||
}
|
||||
return false
|
||||
|
||||
}
|
||||
|
||||
// Root returns the current root of the radix tree within this
|
||||
// transaction. The root is not safe across insert and delete operations,
|
||||
// but can be used to read the current state during a transaction.
|
||||
func (t *Txn) Root() *Node {
|
||||
return t.root
|
||||
}
|
||||
|
||||
// Get is used to lookup a specific key, returning
|
||||
// the value and if it was found
|
||||
func (t *Txn) Get(k []byte) (interface{}, bool) {
|
||||
return t.root.Get(k)
|
||||
}
|
||||
|
||||
// GetWatch is used to lookup a specific key, returning
|
||||
// the watch channel, value and if it was found
|
||||
func (t *Txn) GetWatch(k []byte) (<-chan struct{}, interface{}, bool) {
|
||||
return t.root.GetWatch(k)
|
||||
}
|
||||
|
||||
// Commit is used to finalize the transaction and return a new tree. If mutation
|
||||
// tracking is turned on then notifications will also be issued.
|
||||
func (t *Txn) Commit() *Tree {
|
||||
nt := t.CommitOnly()
|
||||
if t.trackMutate {
|
||||
t.Notify()
|
||||
}
|
||||
return nt
|
||||
}
|
||||
|
||||
// CommitOnly is used to finalize the transaction and return a new tree, but
|
||||
// does not issue any notifications until Notify is called.
|
||||
func (t *Txn) CommitOnly() *Tree {
|
||||
nt := &Tree{t.root, t.size}
|
||||
t.writable = nil
|
||||
return nt
|
||||
}
|
||||
|
||||
// slowNotify does a complete comparison of the before and after trees in order
|
||||
// to trigger notifications. This doesn't require any additional state but it
|
||||
// is very expensive to compute.
|
||||
func (t *Txn) slowNotify() {
|
||||
snapIter := t.snap.rawIterator()
|
||||
rootIter := t.root.rawIterator()
|
||||
for snapIter.Front() != nil || rootIter.Front() != nil {
|
||||
// If we've exhausted the nodes in the old snapshot, we know
|
||||
// there's nothing remaining to notify.
|
||||
if snapIter.Front() == nil {
|
||||
return
|
||||
}
|
||||
snapElem := snapIter.Front()
|
||||
|
||||
// If we've exhausted the nodes in the new root, we know we need
|
||||
// to invalidate everything that remains in the old snapshot. We
|
||||
// know from the loop condition there's something in the old
|
||||
// snapshot.
|
||||
if rootIter.Front() == nil {
|
||||
close(snapElem.mutateCh)
|
||||
if snapElem.isLeaf() {
|
||||
close(snapElem.leaf.mutateCh)
|
||||
}
|
||||
snapIter.Next()
|
||||
continue
|
||||
}
|
||||
|
||||
// Do one string compare so we can check the various conditions
|
||||
// below without repeating the compare.
|
||||
cmp := strings.Compare(snapIter.Path(), rootIter.Path())
|
||||
|
||||
// If the snapshot is behind the root, then we must have deleted
|
||||
// this node during the transaction.
|
||||
if cmp < 0 {
|
||||
close(snapElem.mutateCh)
|
||||
if snapElem.isLeaf() {
|
||||
close(snapElem.leaf.mutateCh)
|
||||
}
|
||||
snapIter.Next()
|
||||
continue
|
||||
}
|
||||
|
||||
// If the snapshot is ahead of the root, then we must have added
|
||||
// this node during the transaction.
|
||||
if cmp > 0 {
|
||||
rootIter.Next()
|
||||
continue
|
||||
}
|
||||
|
||||
// If we have the same path, then we need to see if we mutated a
|
||||
// node and possibly the leaf.
|
||||
rootElem := rootIter.Front()
|
||||
if snapElem != rootElem {
|
||||
close(snapElem.mutateCh)
|
||||
if snapElem.leaf != nil && (snapElem.leaf != rootElem.leaf) {
|
||||
close(snapElem.leaf.mutateCh)
|
||||
}
|
||||
}
|
||||
snapIter.Next()
|
||||
rootIter.Next()
|
||||
}
|
||||
}
|
||||
|
||||
// Notify is used along with TrackMutate to trigger notifications. This must
|
||||
// only be done once a transaction is committed via CommitOnly, and it is called
|
||||
// automatically by Commit.
|
||||
func (t *Txn) Notify() {
|
||||
if !t.trackMutate {
|
||||
return
|
||||
}
|
||||
|
||||
// If we've overflowed the tracking state we can't use it in any way and
|
||||
// need to do a full tree compare.
|
||||
if t.trackOverflow {
|
||||
t.slowNotify()
|
||||
} else {
|
||||
for ch := range t.trackChannels {
|
||||
close(ch)
|
||||
}
|
||||
}
|
||||
|
||||
// Clean up the tracking state so that a re-notify is safe (will trigger
|
||||
// the else clause above which will be a no-op).
|
||||
t.trackChannels = nil
|
||||
t.trackOverflow = false
|
||||
}
|
||||
|
||||
// Insert is used to add or update a given key. The return provides
|
||||
// the new tree, previous value and a bool indicating if any was set.
|
||||
func (t *Tree) Insert(k []byte, v interface{}) (*Tree, interface{}, bool) {
|
||||
txn := t.Txn()
|
||||
old, ok := txn.Insert(k, v)
|
||||
return txn.Commit(), old, ok
|
||||
}
|
||||
|
||||
// Delete is used to delete a given key. Returns the new tree,
|
||||
// old value if any, and a bool indicating if the key was set.
|
||||
func (t *Tree) Delete(k []byte) (*Tree, interface{}, bool) {
|
||||
txn := t.Txn()
|
||||
old, ok := txn.Delete(k)
|
||||
return txn.Commit(), old, ok
|
||||
}
|
||||
|
||||
// DeletePrefix is used to delete all nodes starting with a given prefix. Returns the new tree,
|
||||
// and a bool indicating if the prefix matched any nodes
|
||||
func (t *Tree) DeletePrefix(k []byte) (*Tree, bool) {
|
||||
txn := t.Txn()
|
||||
ok := txn.DeletePrefix(k)
|
||||
return txn.Commit(), ok
|
||||
}
|
||||
|
||||
// Root returns the root node of the tree which can be used for richer
|
||||
// query operations.
|
||||
func (t *Tree) Root() *Node {
|
||||
return t.root
|
||||
}
|
||||
|
||||
// Get is used to lookup a specific key, returning
|
||||
// the value and if it was found
|
||||
func (t *Tree) Get(k []byte) (interface{}, bool) {
|
||||
return t.root.Get(k)
|
||||
}
|
||||
|
||||
// longestPrefix finds the length of the shared prefix
|
||||
// of two strings
|
||||
func longestPrefix(k1, k2 []byte) int {
|
||||
max := len(k1)
|
||||
if l := len(k2); l < max {
|
||||
max = l
|
||||
}
|
||||
var i int
|
||||
for i = 0; i < max; i++ {
|
||||
if k1[i] != k2[i] {
|
||||
break
|
||||
}
|
||||
}
|
||||
return i
|
||||
}
|
||||
|
||||
// concat two byte slices, returning a third new copy
|
||||
func concat(a, b []byte) []byte {
|
||||
c := make([]byte, len(a)+len(b))
|
||||
copy(c, a)
|
||||
copy(c[len(a):], b)
|
||||
return c
|
||||
}
|
||||
File diff suppressed because it is too large
Load Diff
|
|
@ -0,0 +1,91 @@
|
|||
package iradix
|
||||
|
||||
import "bytes"
|
||||
|
||||
// Iterator is used to iterate over a set of nodes
|
||||
// in pre-order
|
||||
type Iterator struct {
|
||||
node *Node
|
||||
stack []edges
|
||||
}
|
||||
|
||||
// SeekPrefixWatch is used to seek the iterator to a given prefix
|
||||
// and returns the watch channel of the finest granularity
|
||||
func (i *Iterator) SeekPrefixWatch(prefix []byte) (watch <-chan struct{}) {
|
||||
// Wipe the stack
|
||||
i.stack = nil
|
||||
n := i.node
|
||||
watch = n.mutateCh
|
||||
search := prefix
|
||||
for {
|
||||
// Check for key exhaution
|
||||
if len(search) == 0 {
|
||||
i.node = n
|
||||
return
|
||||
}
|
||||
|
||||
// Look for an edge
|
||||
_, n = n.getEdge(search[0])
|
||||
if n == nil {
|
||||
i.node = nil
|
||||
return
|
||||
}
|
||||
|
||||
// Update to the finest granularity as the search makes progress
|
||||
watch = n.mutateCh
|
||||
|
||||
// Consume the search prefix
|
||||
if bytes.HasPrefix(search, n.prefix) {
|
||||
search = search[len(n.prefix):]
|
||||
|
||||
} else if bytes.HasPrefix(n.prefix, search) {
|
||||
i.node = n
|
||||
return
|
||||
} else {
|
||||
i.node = nil
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// SeekPrefix is used to seek the iterator to a given prefix
|
||||
func (i *Iterator) SeekPrefix(prefix []byte) {
|
||||
i.SeekPrefixWatch(prefix)
|
||||
}
|
||||
|
||||
// Next returns the next node in order
|
||||
func (i *Iterator) Next() ([]byte, interface{}, bool) {
|
||||
// Initialize our stack if needed
|
||||
if i.stack == nil && i.node != nil {
|
||||
i.stack = []edges{
|
||||
edges{
|
||||
edge{node: i.node},
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
for len(i.stack) > 0 {
|
||||
// Inspect the last element of the stack
|
||||
n := len(i.stack)
|
||||
last := i.stack[n-1]
|
||||
elem := last[0].node
|
||||
|
||||
// Update the stack
|
||||
if len(last) > 1 {
|
||||
i.stack[n-1] = last[1:]
|
||||
} else {
|
||||
i.stack = i.stack[:n-1]
|
||||
}
|
||||
|
||||
// Push the edges onto the frontier
|
||||
if len(elem.edges) > 0 {
|
||||
i.stack = append(i.stack, elem.edges)
|
||||
}
|
||||
|
||||
// Return the leaf values if any
|
||||
if elem.leaf != nil {
|
||||
return elem.leaf.key, elem.leaf.val, true
|
||||
}
|
||||
}
|
||||
return nil, nil, false
|
||||
}
|
||||
|
|
@ -0,0 +1,292 @@
|
|||
package iradix
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"sort"
|
||||
)
|
||||
|
||||
// WalkFn is used when walking the tree. Takes a
|
||||
// key and value, returning if iteration should
|
||||
// be terminated.
|
||||
type WalkFn func(k []byte, v interface{}) bool
|
||||
|
||||
// leafNode is used to represent a value
|
||||
type leafNode struct {
|
||||
mutateCh chan struct{}
|
||||
key []byte
|
||||
val interface{}
|
||||
}
|
||||
|
||||
// edge is used to represent an edge node
|
||||
type edge struct {
|
||||
label byte
|
||||
node *Node
|
||||
}
|
||||
|
||||
// Node is an immutable node in the radix tree
|
||||
type Node struct {
|
||||
// mutateCh is closed if this node is modified
|
||||
mutateCh chan struct{}
|
||||
|
||||
// leaf is used to store possible leaf
|
||||
leaf *leafNode
|
||||
|
||||
// prefix is the common prefix we ignore
|
||||
prefix []byte
|
||||
|
||||
// Edges should be stored in-order for iteration.
|
||||
// We avoid a fully materialized slice to save memory,
|
||||
// since in most cases we expect to be sparse
|
||||
edges edges
|
||||
}
|
||||
|
||||
func (n *Node) isLeaf() bool {
|
||||
return n.leaf != nil
|
||||
}
|
||||
|
||||
func (n *Node) addEdge(e edge) {
|
||||
num := len(n.edges)
|
||||
idx := sort.Search(num, func(i int) bool {
|
||||
return n.edges[i].label >= e.label
|
||||
})
|
||||
n.edges = append(n.edges, e)
|
||||
if idx != num {
|
||||
copy(n.edges[idx+1:], n.edges[idx:num])
|
||||
n.edges[idx] = e
|
||||
}
|
||||
}
|
||||
|
||||
func (n *Node) replaceEdge(e edge) {
|
||||
num := len(n.edges)
|
||||
idx := sort.Search(num, func(i int) bool {
|
||||
return n.edges[i].label >= e.label
|
||||
})
|
||||
if idx < num && n.edges[idx].label == e.label {
|
||||
n.edges[idx].node = e.node
|
||||
return
|
||||
}
|
||||
panic("replacing missing edge")
|
||||
}
|
||||
|
||||
func (n *Node) getEdge(label byte) (int, *Node) {
|
||||
num := len(n.edges)
|
||||
idx := sort.Search(num, func(i int) bool {
|
||||
return n.edges[i].label >= label
|
||||
})
|
||||
if idx < num && n.edges[idx].label == label {
|
||||
return idx, n.edges[idx].node
|
||||
}
|
||||
return -1, nil
|
||||
}
|
||||
|
||||
func (n *Node) delEdge(label byte) {
|
||||
num := len(n.edges)
|
||||
idx := sort.Search(num, func(i int) bool {
|
||||
return n.edges[i].label >= label
|
||||
})
|
||||
if idx < num && n.edges[idx].label == label {
|
||||
copy(n.edges[idx:], n.edges[idx+1:])
|
||||
n.edges[len(n.edges)-1] = edge{}
|
||||
n.edges = n.edges[:len(n.edges)-1]
|
||||
}
|
||||
}
|
||||
|
||||
func (n *Node) GetWatch(k []byte) (<-chan struct{}, interface{}, bool) {
|
||||
search := k
|
||||
watch := n.mutateCh
|
||||
for {
|
||||
// Check for key exhaustion
|
||||
if len(search) == 0 {
|
||||
if n.isLeaf() {
|
||||
return n.leaf.mutateCh, n.leaf.val, true
|
||||
}
|
||||
break
|
||||
}
|
||||
|
||||
// Look for an edge
|
||||
_, n = n.getEdge(search[0])
|
||||
if n == nil {
|
||||
break
|
||||
}
|
||||
|
||||
// Update to the finest granularity as the search makes progress
|
||||
watch = n.mutateCh
|
||||
|
||||
// Consume the search prefix
|
||||
if bytes.HasPrefix(search, n.prefix) {
|
||||
search = search[len(n.prefix):]
|
||||
} else {
|
||||
break
|
||||
}
|
||||
}
|
||||
return watch, nil, false
|
||||
}
|
||||
|
||||
func (n *Node) Get(k []byte) (interface{}, bool) {
|
||||
_, val, ok := n.GetWatch(k)
|
||||
return val, ok
|
||||
}
|
||||
|
||||
// LongestPrefix is like Get, but instead of an
|
||||
// exact match, it will return the longest prefix match.
|
||||
func (n *Node) LongestPrefix(k []byte) ([]byte, interface{}, bool) {
|
||||
var last *leafNode
|
||||
search := k
|
||||
for {
|
||||
// Look for a leaf node
|
||||
if n.isLeaf() {
|
||||
last = n.leaf
|
||||
}
|
||||
|
||||
// Check for key exhaution
|
||||
if len(search) == 0 {
|
||||
break
|
||||
}
|
||||
|
||||
// Look for an edge
|
||||
_, n = n.getEdge(search[0])
|
||||
if n == nil {
|
||||
break
|
||||
}
|
||||
|
||||
// Consume the search prefix
|
||||
if bytes.HasPrefix(search, n.prefix) {
|
||||
search = search[len(n.prefix):]
|
||||
} else {
|
||||
break
|
||||
}
|
||||
}
|
||||
if last != nil {
|
||||
return last.key, last.val, true
|
||||
}
|
||||
return nil, nil, false
|
||||
}
|
||||
|
||||
// Minimum is used to return the minimum value in the tree
|
||||
func (n *Node) Minimum() ([]byte, interface{}, bool) {
|
||||
for {
|
||||
if n.isLeaf() {
|
||||
return n.leaf.key, n.leaf.val, true
|
||||
}
|
||||
if len(n.edges) > 0 {
|
||||
n = n.edges[0].node
|
||||
} else {
|
||||
break
|
||||
}
|
||||
}
|
||||
return nil, nil, false
|
||||
}
|
||||
|
||||
// Maximum is used to return the maximum value in the tree
|
||||
func (n *Node) Maximum() ([]byte, interface{}, bool) {
|
||||
for {
|
||||
if num := len(n.edges); num > 0 {
|
||||
n = n.edges[num-1].node
|
||||
continue
|
||||
}
|
||||
if n.isLeaf() {
|
||||
return n.leaf.key, n.leaf.val, true
|
||||
} else {
|
||||
break
|
||||
}
|
||||
}
|
||||
return nil, nil, false
|
||||
}
|
||||
|
||||
// Iterator is used to return an iterator at
|
||||
// the given node to walk the tree
|
||||
func (n *Node) Iterator() *Iterator {
|
||||
return &Iterator{node: n}
|
||||
}
|
||||
|
||||
// rawIterator is used to return a raw iterator at the given node to walk the
|
||||
// tree.
|
||||
func (n *Node) rawIterator() *rawIterator {
|
||||
iter := &rawIterator{node: n}
|
||||
iter.Next()
|
||||
return iter
|
||||
}
|
||||
|
||||
// Walk is used to walk the tree
|
||||
func (n *Node) Walk(fn WalkFn) {
|
||||
recursiveWalk(n, fn)
|
||||
}
|
||||
|
||||
// WalkPrefix is used to walk the tree under a prefix
|
||||
func (n *Node) WalkPrefix(prefix []byte, fn WalkFn) {
|
||||
search := prefix
|
||||
for {
|
||||
// Check for key exhaution
|
||||
if len(search) == 0 {
|
||||
recursiveWalk(n, fn)
|
||||
return
|
||||
}
|
||||
|
||||
// Look for an edge
|
||||
_, n = n.getEdge(search[0])
|
||||
if n == nil {
|
||||
break
|
||||
}
|
||||
|
||||
// Consume the search prefix
|
||||
if bytes.HasPrefix(search, n.prefix) {
|
||||
search = search[len(n.prefix):]
|
||||
|
||||
} else if bytes.HasPrefix(n.prefix, search) {
|
||||
// Child may be under our search prefix
|
||||
recursiveWalk(n, fn)
|
||||
return
|
||||
} else {
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// WalkPath is used to walk the tree, but only visiting nodes
|
||||
// from the root down to a given leaf. Where WalkPrefix walks
|
||||
// all the entries *under* the given prefix, this walks the
|
||||
// entries *above* the given prefix.
|
||||
func (n *Node) WalkPath(path []byte, fn WalkFn) {
|
||||
search := path
|
||||
for {
|
||||
// Visit the leaf values if any
|
||||
if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
|
||||
return
|
||||
}
|
||||
|
||||
// Check for key exhaution
|
||||
if len(search) == 0 {
|
||||
return
|
||||
}
|
||||
|
||||
// Look for an edge
|
||||
_, n = n.getEdge(search[0])
|
||||
if n == nil {
|
||||
return
|
||||
}
|
||||
|
||||
// Consume the search prefix
|
||||
if bytes.HasPrefix(search, n.prefix) {
|
||||
search = search[len(n.prefix):]
|
||||
} else {
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// recursiveWalk is used to do a pre-order walk of a node
|
||||
// recursively. Returns true if the walk should be aborted
|
||||
func recursiveWalk(n *Node, fn WalkFn) bool {
|
||||
// Visit the leaf values if any
|
||||
if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
|
||||
return true
|
||||
}
|
||||
|
||||
// Recurse on the children
|
||||
for _, e := range n.edges {
|
||||
if recursiveWalk(e.node, fn) {
|
||||
return true
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
|
@ -0,0 +1,78 @@
|
|||
package iradix
|
||||
|
||||
// rawIterator visits each of the nodes in the tree, even the ones that are not
|
||||
// leaves. It keeps track of the effective path (what a leaf at a given node
|
||||
// would be called), which is useful for comparing trees.
|
||||
type rawIterator struct {
|
||||
// node is the starting node in the tree for the iterator.
|
||||
node *Node
|
||||
|
||||
// stack keeps track of edges in the frontier.
|
||||
stack []rawStackEntry
|
||||
|
||||
// pos is the current position of the iterator.
|
||||
pos *Node
|
||||
|
||||
// path is the effective path of the current iterator position,
|
||||
// regardless of whether the current node is a leaf.
|
||||
path string
|
||||
}
|
||||
|
||||
// rawStackEntry is used to keep track of the cumulative common path as well as
|
||||
// its associated edges in the frontier.
|
||||
type rawStackEntry struct {
|
||||
path string
|
||||
edges edges
|
||||
}
|
||||
|
||||
// Front returns the current node that has been iterated to.
|
||||
func (i *rawIterator) Front() *Node {
|
||||
return i.pos
|
||||
}
|
||||
|
||||
// Path returns the effective path of the current node, even if it's not actually
|
||||
// a leaf.
|
||||
func (i *rawIterator) Path() string {
|
||||
return i.path
|
||||
}
|
||||
|
||||
// Next advances the iterator to the next node.
|
||||
func (i *rawIterator) Next() {
|
||||
// Initialize our stack if needed.
|
||||
if i.stack == nil && i.node != nil {
|
||||
i.stack = []rawStackEntry{
|
||||
rawStackEntry{
|
||||
edges: edges{
|
||||
edge{node: i.node},
|
||||
},
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
for len(i.stack) > 0 {
|
||||
// Inspect the last element of the stack.
|
||||
n := len(i.stack)
|
||||
last := i.stack[n-1]
|
||||
elem := last.edges[0].node
|
||||
|
||||
// Update the stack.
|
||||
if len(last.edges) > 1 {
|
||||
i.stack[n-1].edges = last.edges[1:]
|
||||
} else {
|
||||
i.stack = i.stack[:n-1]
|
||||
}
|
||||
|
||||
// Push the edges onto the frontier.
|
||||
if len(elem.edges) > 0 {
|
||||
path := last.path + string(elem.prefix)
|
||||
i.stack = append(i.stack, rawStackEntry{path, elem.edges})
|
||||
}
|
||||
|
||||
i.pos = elem
|
||||
i.path = last.path + string(elem.prefix)
|
||||
return
|
||||
}
|
||||
|
||||
i.pos = nil
|
||||
i.path = ""
|
||||
}
|
||||
Loading…
Reference in New Issue