From 5db2437bd44411f9d55d9b8c31875d0840666823 Mon Sep 17 00:00:00 2001
From: Jeromy <jeromyj@gmail.com>
Date: Sun, 25 Oct 2015 22:37:45 -0700
Subject: [PATCH] Add nocache option

License: MIT
Signed-off-by: Jeromy <jeromyj@gmail.com>
---
 core/commands/ipns.go  | 21 +++++++++++++++++----
 namesys/routing.go     | 35 +++++++++++++++++++++++++++--------
 repo/config/init.go    |  4 ++++
 routing/dht/routing.go |  5 ++++-
 4 files changed, 52 insertions(+), 13 deletions(-)

diff --git a/core/commands/ipns.go b/core/commands/ipns.go
index eb4bc9ed66d..59128691402 100644
--- a/core/commands/ipns.go
+++ b/core/commands/ipns.go
@@ -45,6 +45,7 @@ Resolve the value of another name:
 	},
 	Options: []cmds.Option{
 		cmds.BoolOption("recursive", "r", "Resolve until the result is not an IPNS name"),
+		cmds.BoolOption("nocache", "n", "Do not used cached entries"),
 	},
 	Run: func(req cmds.Request, res cmds.Response) {
 
@@ -62,15 +63,27 @@ Resolve the value of another name:
 			}
 		}
 
-		var resolver namesys.Resolver
-		resolver = n.Namesys
-		if local, _, _ := req.Option("local").Bool(); local {
+		nocache, _, _ := req.Option("nocache").Bool()
+		local, _, _ := req.Option("local").Bool()
+
+		// default to nodes namesys resolver
+		var resolver namesys.Resolver = n.Namesys
+
+		if local && nocache {
+			res.SetError(errors.New("cannot specify both local and nocache"), cmds.ErrNormal)
+			return
+		}
+
+		if local {
 			offroute := offline.NewOfflineRouter(n.Repo.Datastore(), n.PrivateKey)
 			resolver = namesys.NewRoutingResolver(offroute, 0)
 		}
 
-		var name string
+		if nocache {
+			resolver = namesys.NewNameSystem(n.Routing, n.Repo.Datastore(), 0)
+		}
 
+		var name string
 		if len(req.Arguments()) == 0 {
 			if n.Identity == "" {
 				res.SetError(errors.New("Identity not loaded!"), cmds.ErrNormal)
diff --git a/namesys/routing.go b/namesys/routing.go
index 99f806dcb68..93161df53b6 100644
--- a/namesys/routing.go
+++ b/namesys/routing.go
@@ -13,6 +13,7 @@ import (
 	pb "github.com/ipfs/go-ipfs/namesys/pb"
 	path "github.com/ipfs/go-ipfs/path"
 	routing "github.com/ipfs/go-ipfs/routing"
+	u "github.com/ipfs/go-ipfs/util"
 	logging "github.com/ipfs/go-ipfs/vendor/QmXJkcEXB6C9h6Ytb6rrUTFU56Ro62zxgrbxTT3dgjQGA8/go-log"
 )
 
@@ -31,25 +32,31 @@ func (r *routingResolver) cacheGet(name string) (path.Path, bool) {
 	r.cachelock.Lock()
 	entry, ok := r.cache[name]
 	r.cachelock.Unlock()
-	if ok && time.Now().Sub(entry.recvd) < r.cachelife {
+	if ok && time.Now().Before(entry.eol) {
 		return entry.val, true
 	}
 
 	return "", false
 }
 
-func (r *routingResolver) cacheSet(name string, val path.Path) {
+func (r *routingResolver) cacheSet(name string, val path.Path, rec *pb.IpnsEntry) {
+	cacheTil := time.Now().Add(r.cachelife)
+	eol, ok := checkEOL(rec)
+	if ok && eol.Before(cacheTil) {
+		cacheTil = eol
+	}
+
 	r.cachelock.Lock()
 	r.cache[name] = cacheEntry{
-		val:   val,
-		recvd: time.Now(),
+		val: val,
+		eol: eol,
 	}
 	r.cachelock.Unlock()
 }
 
 type cacheEntry struct {
-	val   path.Path
-	recvd time.Time
+	val path.Path
+	eol time.Time
 }
 
 // NewRoutingResolver constructs a name resolver using the IPFS Routing system
@@ -133,13 +140,25 @@ func (r *routingResolver) resolveOnce(ctx context.Context, name string) (path.Pa
 		if err != nil {
 			return "", err
 		}
-		r.cacheSet(name, p)
+
+		r.cacheSet(name, p, entry)
 		return p, nil
 	} else {
 		// Its an old style multihash record
 		log.Warning("Detected old style multihash record")
 		p := path.FromKey(key.Key(valh))
-		r.cacheSet(name, p)
+		r.cacheSet(name, p, entry)
 		return p, nil
 	}
 }
+
+func checkEOL(e *pb.IpnsEntry) (time.Time, bool) {
+	if e.GetValidityType() == pb.IpnsEntry_EOL {
+		eol, err := u.ParseRFC3339(string(e.GetValidity()))
+		if err != nil {
+			return time.Time{}, false
+		}
+		return eol, true
+	}
+	return time.Time{}, false
+}
diff --git a/repo/config/init.go b/repo/config/init.go
index 49d0a1ecb08..409edcd554c 100644
--- a/repo/config/init.go
+++ b/repo/config/init.go
@@ -64,6 +64,10 @@ func Init(out io.Writer, nBitsForKeypair int) (*Config, error) {
 			IPNS: "/ipns",
 		},
 
+		Ipns: Ipns{
+			ResolveCacheTime: "1m",
+		},
+
 		// tracking ipfs version used to generate the init folder and adding
 		// update checker default setting.
 		Version: VersionDefaultValue(),
diff --git a/routing/dht/routing.go b/routing/dht/routing.go
index 4bf2517c4d8..5f020619930 100644
--- a/routing/dht/routing.go
+++ b/routing/dht/routing.go
@@ -84,7 +84,10 @@ func (dht *IpfsDHT) GetValue(ctx context.Context, key key.Key) ([]byte, error) {
 	ctx, cancel := context.WithTimeout(ctx, time.Minute)
 	defer cancel()
 
-	vals, err := dht.GetValues(ctx, key, (KValue/2)+1)
+	// retrieve a majority of the expected record count
+	majority := (KValue / 2) + 1
+
+	vals, err := dht.GetValues(ctx, key, majority)
 	if err != nil {
 		return nil, err
 	}