pgraph: Remove use of Flags struct in favour of Value API

One small step to completely cleaning up the pgraph package so that we
can eventually fix the code that would otherwise create a cycle!

lib/main.go

@@ -442,7 +442,7 @@ func (obj *Main) Run() error {
 				}
 				continue
 			}
-			newGraph.Flags = pgraph.Flags{Debug: obj.Flags.Debug}
+			newGraph.SetValue("debug", obj.Flags.Debug)
 			// pass in the information we need
 			newGraph.AssociateData(&resources.Data{
 				Hostname:   hostname,

pgraph/actions.go

@@ -28,6 +28,7 @@ import (
 	"github.com/purpleidea/mgmt/event"
 	"github.com/purpleidea/mgmt/prometheus"
 	"github.com/purpleidea/mgmt/resources"
+	"github.com/purpleidea/mgmt/util"
 
 	multierr "github.com/hashicorp/go-multierror"
 	errwrap "github.com/pkg/errors"
@@ -54,7 +55,7 @@ func (g *Graph) OKTimestamp(v *Vertex) bool {
 		// if they're equal (eg: on init of 0) then we also can't run
 		// b/c we should let our pre-req's go first...
 		x, y := v.GetTimestamp(), n.GetTimestamp()
-		if g.Flags.Debug {
+		if b, ok := g.Value("debug"); ok && util.Bool(b) {
 			log.Printf("%s[%s]: OKTimestamp: (%v) >= %s[%s](%v): !%v", v.GetKind(), v.GetName(), x, n.GetKind(), n.GetName(), y, x >= y)
 		}
 		if x >= y {
@@ -81,7 +82,7 @@ func (g *Graph) Poke(v *Vertex) error {
 		// needs to be poked if already running, or not running though!
 		// TODO: does this need an || activity flag?
 		if n.Res.GetState() != resources.ResStateProcess {
-			if g.Flags.Debug {
+			if b, ok := g.Value("debug"); ok && util.Bool(b) {
 				log.Printf("%s[%s]: Poke: %s[%s]", v.GetKind(), v.GetName(), n.GetKind(), n.GetName())
 			}
 			wg.Add(1)
@@ -93,7 +94,7 @@ func (g *Graph) Poke(v *Vertex) error {
 			}(n)
 
 		} else {
-			if g.Flags.Debug {
+			if b, ok := g.Value("debug"); ok && util.Bool(b) {
 				log.Printf("%s[%s]: Poke: %s[%s]: Skipped!", v.GetKind(), v.GetName(), n.GetKind(), n.GetName())
 			}
 		}
@@ -116,7 +117,7 @@ func (g *Graph) BackPoke(v *Vertex) {
 		// TODO: implement a stateLT (less than) to tell if something
 		// happens earlier in the state cycle and that doesn't wrap nil
 		if x >= y && (s != resources.ResStateProcess && s != resources.ResStateCheckApply) {
-			if g.Flags.Debug {
+			if b, ok := g.Value("debug"); ok && util.Bool(b) {
 				log.Printf("%s[%s]: BackPoke: %s[%s]", v.GetKind(), v.GetName(), n.GetKind(), n.GetName())
 			}
 			wg.Add(1)
@@ -126,7 +127,7 @@ func (g *Graph) BackPoke(v *Vertex) {
 			}(n)
 
 		} else {
-			if g.Flags.Debug {
+			if b, ok := g.Value("debug"); ok && util.Bool(b) {
 				log.Printf("%s[%s]: BackPoke: %s[%s]: Skipped!", v.GetKind(), v.GetName(), n.GetKind(), n.GetName())
 			}
 		}
@@ -171,7 +172,7 @@ func (g *Graph) SetDownstreamRefresh(v *Vertex, b bool) {
 // Process is the primary function to execute for a particular vertex in the graph.
 func (g *Graph) Process(v *Vertex) error {
 	obj := v.Res
-	if g.Flags.Debug {
+	if b, ok := g.Value("debug"); ok && util.Bool(b) {
 		log.Printf("%s[%s]: Process()", obj.GetKind(), obj.GetName())
 	}
 	// FIXME: should these SetState methods be here or after the sema code?
@@ -186,7 +187,7 @@ func (g *Graph) Process(v *Vertex) error {
 		return nil
 	}
 	// timestamp must be okay...
-	if g.Flags.Debug {
+	if b, ok := g.Value("debug"); ok && util.Bool(b) {
 		log.Printf("%s[%s]: OKTimestamp(%v)", obj.GetKind(), obj.GetName(), v.GetTimestamp())
 	}
 
@@ -198,7 +199,7 @@ func (g *Graph) Process(v *Vertex) error {
 	// The exception is that semaphores with a zero count will always block!
 	// TODO: Add a close mechanism to close/unblock zero count semaphores...
 	semas := obj.Meta().Sema
-	if g.Flags.Debug && len(semas) > 0 {
+	if b, ok := g.Value("debug"); ok && util.Bool(b) && len(semas) > 0 {
 		log.Printf("%s[%s]: Sema: P(%s)", obj.GetKind(), obj.GetName(), strings.Join(semas, ", "))
 	}
 	if err := g.SemaLock(semas); err != nil { // lock
@@ -206,7 +207,7 @@ func (g *Graph) Process(v *Vertex) error {
 		return fmt.Errorf("shutdown of semaphores")
 	}
 	defer g.SemaUnlock(semas) // unlock
-	if g.Flags.Debug && len(semas) > 0 {
+	if b, ok := g.Value("debug"); ok && util.Bool(b) && len(semas) > 0 {
 		defer log.Printf("%s[%s]: Sema: V(%s)", obj.GetKind(), obj.GetName(), strings.Join(semas, ", "))
 	}
 
@@ -230,7 +231,7 @@ func (g *Graph) Process(v *Vertex) error {
 	var checkOK bool
 	var err error
 
-	if g.Flags.Debug {
+	if b, ok := g.Value("debug"); ok && util.Bool(b) {
 		log.Printf("%s[%s]: CheckApply(%t)", obj.GetKind(), obj.GetName(), !noop)
 	}
 
@@ -267,7 +268,7 @@ func (g *Graph) Process(v *Vertex) error {
 			if !checkOK { // something changed, restart timer
 				cuid, _, _ := v.Res.ConvergerUIDs() // get the converger uid used to report status
 				cuid.ResetTimer()                   // activity!
-				if g.Flags.Debug {
+				if b, ok := g.Value("debug"); ok && util.Bool(b) {
 					log.Printf("%s[%s]: Converger: ResetTimer", obj.GetKind(), obj.GetName())
 				}
 			}
@@ -277,7 +278,7 @@ func (g *Graph) Process(v *Vertex) error {
 	if checkOK && err != nil { // should never return this way
 		log.Fatalf("%s[%s]: CheckApply(): %t, %+v", obj.GetKind(), obj.GetName(), checkOK, err)
 	}
-	if g.Flags.Debug {
+	if b, ok := g.Value("debug"); ok && util.Bool(b) {
 		log.Printf("%s[%s]: CheckApply(): %t, %v", obj.GetKind(), obj.GetName(), checkOK, err)
 	}
 
@@ -371,7 +372,7 @@ Loop:
 
 			// if process started, but no action yet, skip!
 			if v.Res.GetState() == resources.ResStateProcess {
-				if g.Flags.Debug {
+				if b, ok := g.Value("debug"); ok && util.Bool(b) {
 					log.Printf("%s[%s]: Skipped event!", v.GetKind(), v.GetName())
 				}
 				ev.ACK() // ready for next message
@@ -382,7 +383,7 @@ Loop:
 			// if running, we skip running a new execution!
 			// if waiting, we skip running a new execution!
 			if running || waiting {
-				if g.Flags.Debug {
+				if b, ok := g.Value("debug"); ok && util.Bool(b) {
 					log.Printf("%s[%s]: Playback added!", v.GetKind(), v.GetName())
 				}
 				playback = true
@@ -477,7 +478,7 @@ Loop:
 			if v.Res.Meta().Poll == 0 { // skip for polling
 				wcuid.SetConverged(false)
 			}
-			if g.Flags.Debug {
+			if b, ok := g.Value("debug"); ok && util.Bool(b) {
 				log.Printf("%s[%s]: CheckApply finished!", v.GetKind(), v.GetName())
 			}
 			done = make(chan struct{}) // reset
@@ -520,7 +521,7 @@ func (g *Graph) Worker(v *Vertex) error {
 	// the Watch() function about which graph it is
 	// running on, which isolates things nicely...
 	obj := v.Res
-	if g.Flags.Debug {
+	if b, ok := g.Value("debug"); ok && util.Bool(b) {
 		log.Printf("%s[%s]: Worker: Running", v.GetKind(), v.GetName())
 		defer log.Printf("%s[%s]: Worker: Stopped", v.GetKind(), v.GetName())
 	}

pgraph/autoedge.go

@@ -23,6 +23,7 @@ import (
 	"log"
 
 	"github.com/purpleidea/mgmt/resources"
+	"github.com/purpleidea/mgmt/util"
 )
 
 // add edges to the vertex in a graph based on if it matches a uid list
@@ -38,7 +39,7 @@ func (g *Graph) addEdgesByMatchingUIDS(v *Vertex, uids []resources.ResUID) []boo
 			if v == vv { // skip self
 				continue
 			}
-			if g.Flags.Debug {
+			if b, ok := g.Value("debug"); ok && util.Bool(b) {
 				log.Printf("Compile: AutoEdge: Match: %s[%s] with UID: %s[%s]", vv.GetKind(), vv.GetName(), uid.GetKind(), uid.GetName())
 			}
 			// we must match to an effective UID for the resource,
@@ -84,7 +85,7 @@ func (g *Graph) AutoEdges() {
 				log.Printf("%s[%s]: Config: The auto edge list is empty!", v.GetKind(), v.GetName())
 				break // inner loop
 			}
-			if g.Flags.Debug {
+			if b, ok := g.Value("debug"); ok && util.Bool(b) {
 				log.Println("Compile: AutoEdge: UIDS:")
 				for i, u := range uids {
 					log.Printf("Compile: AutoEdge: UID%d: %v", i, u)

pgraph/autogroup.go

@@ -21,6 +21,8 @@ import (
 	"fmt"
 	"log"
 
+	"github.com/purpleidea/mgmt/util"
+
 	errwrap "github.com/pkg/errors"
 )
 
@@ -310,7 +312,7 @@ func (g *Graph) autoGroup(ag AutoGrouper) chan string {
 			wStr := fmt.Sprintf("%s", w)
 
 			if err := ag.vertexCmp(v, w); err != nil { // cmp ?
-				if g.Flags.Debug {
+				if b, ok := g.Value("debug"); ok && util.Bool(b) {
 					strch <- fmt.Sprintf("Compile: Grouping: !GroupCmp for: %s into %s", wStr, vStr)
 				}
 

pgraph/pgraph.go

@@ -42,11 +42,6 @@ const (
 	graphStatePaused
 )
 
-// Flags contains specific constants used by the graph.
-type Flags struct {
-	Debug bool
-}
-
 // Graph is the graph structure in this library.
 // The graph abstract data type (ADT) is defined as follows:
 // * the directed graph arrows point from left to right ( -> )
@@ -60,7 +55,6 @@ type Graph struct {
 	kv        map[string]interface{}        // some values associated with the graph
 
 	// legacy
-	Flags     Flags
 	state     graphState
 	fastPause bool        // used to disable pokes for a fast pause
 	mutex     *sync.Mutex // used when modifying graph State variable
@@ -158,7 +152,6 @@ func (g *Graph) Copy() *Graph {
 		kv:        g.kv,
 
 		// legacy
-		Flags:     g.Flags,
 		state:     g.state,
 		mutex:     g.mutex,
 		wg:        g.wg,

util/interfaces.go

@@ -0,0 +1,27 @@
+// Mgmt
+// Copyright (C) 2013-2017+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package util
+
+// Bool returns the interface value if it is a bool, and otherwise it panics.
+func Bool(x interface{}) bool {
+	b, ok := x.(bool)
+	if !ok {
+		panic("not a bool")
+	}
+	return b
+}