lang: funcs: txn: Move transaction code to a new package

This also makes it public, although it is designed for internal use
only.
This commit is contained in:
James Shubin
2024-01-22 14:09:04 -05:00
parent 28eacdb2bb
commit 4ad7edc35e
4 changed files with 60 additions and 29 deletions

View File

@@ -32,6 +32,7 @@ import (
"github.com/purpleidea/mgmt/engine/local"
"github.com/purpleidea/mgmt/lang/funcs/ref"
"github.com/purpleidea/mgmt/lang/funcs/structs"
"github.com/purpleidea/mgmt/lang/funcs/txn"
"github.com/purpleidea/mgmt/lang/interfaces"
"github.com/purpleidea/mgmt/lang/types"
"github.com/purpleidea/mgmt/pgraph"
@@ -230,13 +231,13 @@ func (obj *Engine) Txn() interfaces.Txn {
obj.wgTxn.Done()
}
}
return (&graphTxn{
return (&txn.GraphTxn{
Lock: obj.Lock,
Unlock: obj.Unlock,
GraphAPI: obj,
RefCount: obj.refCount, // reference counting
FreeFunc: free,
}).init()
}).Init()
}
// addVertex is the lockless version of the AddVertex function. This is needed
@@ -1526,7 +1527,7 @@ type state struct {
input chan types.Value // the top level type must be a struct
output chan types.Value
txn interfaces.Txn // API of graphTxn struct to pass to each function
txn interfaces.Txn // API of GraphTxn struct to pass to each function
//init bool // have we run Init on our func?
//ready bool // has it received all the args it needs at least once?

View File

@@ -15,9 +15,8 @@
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
// Package dage implements a DAG function engine.
// TODO: can we rename this to something more interesting?
package dage
// Package txn contains the implementation of the graph transaction system.
package txn
import (
"fmt"
@@ -255,11 +254,11 @@ func (obj *opDeleteVertex) String() string {
return fmt.Sprintf("DeleteVertex: %+v", obj.F)
}
// graphTxn holds the state of a transaction and runs it when needed. When this
// GraphTxn holds the state of a transaction and runs it when needed. When this
// has been setup and initialized, it implements the Txn API that can be used by
// functions in their Stream method to modify the function graph while it is
// "running".
type graphTxn struct {
type GraphTxn struct {
// Lock is a handle to the lock function to call before the operation.
Lock func()
@@ -289,9 +288,9 @@ type graphTxn struct {
mutex *sync.Mutex
}
// init must be called to initialized the struct before first use. This is
// private because the creator, not the user should run it.
func (obj *graphTxn) init() interfaces.Txn {
// Init must be called to initialized the struct before first use. This should
// be called by the struct creator, not the user.
func (obj *GraphTxn) Init() interfaces.Txn {
obj.ops = []opfn{}
obj.rev = []opfn{}
obj.mutex = &sync.Mutex{}
@@ -303,21 +302,21 @@ func (obj *graphTxn) init() interfaces.Txn {
// This allows you to do an Add*/Commit/Reverse that isn't affected by a
// different user of this transaction.
// TODO: FreeFunc isn't well supported here. Replace or remove this entirely?
func (obj *graphTxn) Copy() interfaces.Txn {
txn := &graphTxn{
func (obj *GraphTxn) Copy() interfaces.Txn {
txn := &GraphTxn{
Lock: obj.Lock,
Unlock: obj.Unlock,
GraphAPI: obj.GraphAPI,
RefCount: obj.RefCount, // this is shared across all txn's
// FreeFunc is shared with the parent.
}
return txn.init()
return txn.Init()
}
// AddVertex adds a vertex to the running graph. The operation will get
// completed when Commit is run.
// XXX: should this be pgraph.Vertex instead of interfaces.Func ?
func (obj *graphTxn) AddVertex(f interfaces.Func) interfaces.Txn {
func (obj *GraphTxn) AddVertex(f interfaces.Func) interfaces.Txn {
obj.mutex.Lock()
defer obj.mutex.Unlock()
@@ -336,7 +335,7 @@ func (obj *graphTxn) AddVertex(f interfaces.Func) interfaces.Txn {
// when Commit is run.
// XXX: should this be pgraph.Vertex instead of interfaces.Func ?
// XXX: should this be pgraph.Edge instead of *interfaces.FuncEdge ?
func (obj *graphTxn) AddEdge(f1, f2 interfaces.Func, fe *interfaces.FuncEdge) interfaces.Txn {
func (obj *GraphTxn) AddEdge(f1, f2 interfaces.Func, fe *interfaces.FuncEdge) interfaces.Txn {
obj.mutex.Lock()
defer obj.mutex.Unlock()
@@ -360,7 +359,7 @@ func (obj *graphTxn) AddEdge(f1, f2 interfaces.Func, fe *interfaces.FuncEdge) in
// DeleteVertex adds a vertex to the running graph. The operation will get
// completed when Commit is run.
// XXX: should this be pgraph.Vertex instead of interfaces.Func ?
func (obj *graphTxn) DeleteVertex(f interfaces.Func) interfaces.Txn {
func (obj *GraphTxn) DeleteVertex(f interfaces.Func) interfaces.Txn {
obj.mutex.Lock()
defer obj.mutex.Unlock()
@@ -379,7 +378,7 @@ func (obj *graphTxn) DeleteVertex(f interfaces.Func) interfaces.Txn {
// when Commit is run. This function panics if your graph contains vertices that
// are not of type interfaces.Func or if your edges are not of type
// *interfaces.FuncEdge.
func (obj *graphTxn) AddGraph(g *pgraph.Graph) interfaces.Txn {
func (obj *GraphTxn) AddGraph(g *pgraph.Graph) interfaces.Txn {
obj.mutex.Lock()
defer obj.mutex.Unlock()
@@ -431,7 +430,7 @@ func (obj *graphTxn) AddGraph(g *pgraph.Graph) interfaces.Txn {
// commit runs the pending transaction. This is the lockless version that is
// only used internally.
func (obj *graphTxn) commit() error {
func (obj *GraphTxn) commit() error {
if len(obj.ops) == 0 { // nothing to do
return nil
}
@@ -526,7 +525,7 @@ func (obj *graphTxn) commit() error {
// Commit success) then this will erase that transaction. Usually you run cycles
// of Commit, followed by Reverse, or only Commit. (You obviously have to
// populate operations before the Commit is run.)
func (obj *graphTxn) Commit() error {
func (obj *GraphTxn) Commit() error {
// Lock our internal state mutex first... this prevents other AddVertex
// or similar calls from interferring with our work here.
obj.mutex.Lock()
@@ -536,7 +535,7 @@ func (obj *graphTxn) Commit() error {
}
// Clear erases any pending transactions that weren't committed yet.
func (obj *graphTxn) Clear() {
func (obj *GraphTxn) Clear() {
obj.mutex.Lock()
defer obj.mutex.Unlock()
@@ -549,7 +548,7 @@ func (obj *graphTxn) Clear() {
// run at the end of a successful Reverse. It is generally recommended to not
// queue any operations for Commit if you plan on doing a Reverse, or to run a
// Clear before running Reverse if you want to discard the pending commits.
func (obj *graphTxn) Reverse() error {
func (obj *GraphTxn) Reverse() error {
obj.mutex.Lock()
defer obj.mutex.Unlock()
@@ -609,7 +608,7 @@ func (obj *graphTxn) Reverse() error {
}
// Erase removes the historical information that Reverse would run after Commit.
func (obj *graphTxn) Erase() {
func (obj *GraphTxn) Erase() {
obj.mutex.Lock()
defer obj.mutex.Unlock()
@@ -620,7 +619,7 @@ func (obj *graphTxn) Erase() {
// It should get called when we're done with any Txn.
// TODO: this is only used for the initial Txn. Consider expanding it's use. We
// might need to allow Clear to call it as part of the clearing.
func (obj *graphTxn) Free() {
func (obj *GraphTxn) Free() {
if obj.FreeFunc != nil {
obj.FreeFunc()
}

View File

@@ -17,7 +17,7 @@
//go:build !root
package dage
package txn
import (
"context"
@@ -25,6 +25,7 @@ import (
"sync"
"testing"
"github.com/purpleidea/mgmt/lang/funcs/ref"
"github.com/purpleidea/mgmt/lang/interfaces"
"github.com/purpleidea/mgmt/pgraph"
"github.com/purpleidea/mgmt/util"
@@ -138,13 +139,13 @@ func TestTxn1(t *testing.T) {
testGraphAPI := &testGraphAPI{graph: graph}
mutex := &sync.Mutex{}
graphTxn := &graphTxn{
graphTxn := &GraphTxn{
GraphAPI: testGraphAPI,
Lock: mutex.Lock,
Unlock: mutex.Unlock,
RefCount: (&ref.Count{}).Init(),
}
txn := graphTxn.init()
txn := graphTxn.Init()
f1 := &testNullFunc{"f1"}
@@ -481,13 +482,13 @@ func TestTxnTable(t *testing.T) {
testGraphAPI := &testGraphAPI{graph: graph}
mutex := &sync.Mutex{}
graphTxn := &graphTxn{
graphTxn := &GraphTxn{
GraphAPI: testGraphAPI,
Lock: mutex.Lock,
Unlock: mutex.Unlock,
RefCount: (&ref.Count{}).Init(),
}
txn := graphTxn.init()
txn := graphTxn.Init()
// Run a list of actions, passing the returned txn (if
// any) to the next action. Any error kills it all.

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@@ -0,0 +1,30 @@
// Mgmt
// Copyright (C) 2013-2023+ 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 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//go:build !root
package txn
import (
"github.com/purpleidea/mgmt/lang/interfaces"
)
func testEdge(name string) *interfaces.FuncEdge {
return &interfaces.FuncEdge{
Args: []string{name},
}
}