Files
mgmt/file.go
James Shubin f39551952f Add pkg auto edge basics with packagekit improvements
This is a monster patch that finally gets the iterative pkg auto edges
working the way they should. For each file, as soon as one matches, we
don't want to keep add dependencies on other file objects under that
tree structure. This reduces the number of necessary edges considerably,
and allows the graph to run more concurrently.
2016-03-10 03:29:51 -05:00

481 lines
12 KiB
Go

// Mgmt
// Copyright (C) 2013-2016+ 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 main
import (
"crypto/sha256"
"encoding/hex"
"gopkg.in/fsnotify.v1"
//"github.com/go-fsnotify/fsnotify" // git master of "gopkg.in/fsnotify.v1"
"io"
"log"
"math"
"os"
"path"
"strings"
"syscall"
)
type FileRes struct {
BaseRes `yaml:",inline"`
Path string `yaml:"path"` // path variable (should default to name)
Dirname string `yaml:"dirname"`
Basename string `yaml:"basename"`
Content string `yaml:"content"`
State string `yaml:"state"` // state: exists/present?, absent, (undefined?)
sha256sum string
}
func NewFileRes(name, path, dirname, basename, content, state string) *FileRes {
// FIXME if path = nil, path = name ...
obj := &FileRes{
BaseRes: BaseRes{
Name: name,
},
Path: path,
Dirname: dirname,
Basename: basename,
Content: content,
State: state,
sha256sum: "",
}
obj.Init()
return obj
}
func (obj *FileRes) Init() {
obj.BaseRes.kind = "File"
obj.BaseRes.Init() // call base init, b/c we're overriding
}
func (obj *FileRes) GetPath() string {
d := Dirname(obj.Path)
b := Basename(obj.Path)
if !obj.Validate() || (obj.Dirname == "" && obj.Basename == "") {
return obj.Path
} else if obj.Dirname == "" {
return d + obj.Basename
} else if obj.Basename == "" {
return obj.Dirname + b
} else { // if obj.dirname != "" && obj.basename != "" {
return obj.Dirname + obj.Basename
}
}
// validate if the params passed in are valid data
func (obj *FileRes) Validate() bool {
if obj.Dirname != "" {
// must end with /
if obj.Dirname[len(obj.Dirname)-1:] != "/" {
return false
}
}
if obj.Basename != "" {
// must not start with /
if obj.Basename[0:1] == "/" {
return false
}
}
return true
}
// File watcher for files and directories
// Modify with caution, probably important to write some test cases first!
// obj.GetPath(): file or directory
func (obj *FileRes) Watch() {
if obj.IsWatching() {
return
}
obj.SetWatching(true)
defer obj.SetWatching(false)
//var recursive bool = false
//var isdir = (obj.GetPath()[len(obj.GetPath())-1:] == "/") // dirs have trailing slashes
//log.Printf("IsDirectory: %v", isdir)
//vertex := obj.GetVertex() // stored with SetVertex
var safename = path.Clean(obj.GetPath()) // no trailing slash
watcher, err := fsnotify.NewWatcher()
if err != nil {
log.Fatal(err)
}
defer watcher.Close()
patharray := PathSplit(safename) // tokenize the path
var index = len(patharray) // starting index
var current string // current "watcher" location
var deltaDepth int // depth delta between watcher and event
var send = false // send event?
var exit = false
var dirty = false
for {
current = strings.Join(patharray[0:index], "/")
if current == "" { // the empty string top is the root dir ("/")
current = "/"
}
if DEBUG {
log.Printf("File[%v]: Watching: %v", obj.GetName(), current) // attempting to watch...
}
// initialize in the loop so that we can reset on rm-ed handles
err = watcher.Add(current)
if err != nil {
if DEBUG {
log.Printf("File[%v]: watcher.Add(%v): Error: %v", obj.GetName(), current, err)
}
if err == syscall.ENOENT {
index-- // usually not found, move up one dir
} else if err == syscall.ENOSPC {
// XXX: occasionally: no space left on device,
// XXX: probably due to lack of inotify watches
log.Printf("%v[%v]: Out of inotify watches!", obj.Kind(), obj.GetName())
log.Fatal(err)
} else {
log.Printf("Unknown file[%v] error:", obj.Name)
log.Fatal(err)
}
index = int(math.Max(1, float64(index)))
continue
}
obj.SetState(resStateWatching) // reset
select {
case event := <-watcher.Events:
if DEBUG {
log.Printf("File[%v]: Watch(%v), Event(%v): %v", obj.GetName(), current, event.Name, event.Op)
}
obj.SetConvergedState(resConvergedNil) // XXX: technically i can detect if the event is erroneous or not first
// the deeper you go, the bigger the deltaDepth is...
// this is the difference between what we're watching,
// and the event... doesn't mean we can't watch deeper
if current == event.Name {
deltaDepth = 0 // i was watching what i was looking for
} else if HasPathPrefix(event.Name, current) {
deltaDepth = len(PathSplit(current)) - len(PathSplit(event.Name)) // -1 or less
} else if HasPathPrefix(current, event.Name) {
deltaDepth = len(PathSplit(event.Name)) - len(PathSplit(current)) // +1 or more
} else {
// TODO different watchers get each others events!
// https://github.com/go-fsnotify/fsnotify/issues/95
// this happened with two values such as:
// event.Name: /tmp/mgmt/f3 and current: /tmp/mgmt/f2
continue
}
//log.Printf("The delta depth is: %v", deltaDepth)
// if we have what we wanted, awesome, send an event...
if event.Name == safename {
//log.Println("Event!")
// FIXME: should all these below cases trigger?
send = true
dirty = true
// file removed, move the watch upwards
if deltaDepth >= 0 && (event.Op&fsnotify.Remove == fsnotify.Remove) {
//log.Println("Removal!")
watcher.Remove(current)
index--
}
// we must be a parent watcher, so descend in
if deltaDepth < 0 {
watcher.Remove(current)
index++
}
// if safename starts with event.Name, we're above, and no event should be sent
} else if HasPathPrefix(safename, event.Name) {
//log.Println("Above!")
if deltaDepth >= 0 && (event.Op&fsnotify.Remove == fsnotify.Remove) {
log.Println("Removal!")
watcher.Remove(current)
index--
}
if deltaDepth < 0 {
log.Println("Parent!")
if PathPrefixDelta(safename, event.Name) == 1 { // we're the parent dir
send = true
dirty = true
}
watcher.Remove(current)
index++
}
// if event.Name startswith safename, send event, we're already deeper
} else if HasPathPrefix(event.Name, safename) {
//log.Println("Event2!")
send = true
dirty = true
}
case err := <-watcher.Errors:
obj.SetConvergedState(resConvergedNil) // XXX ?
log.Println("error:", err)
log.Fatal(err)
//obj.events <- fmt.Sprintf("file: %v", "error") // XXX: how should we handle errors?
case event := <-obj.events:
obj.SetConvergedState(resConvergedNil)
if exit, send = obj.ReadEvent(&event); exit {
return // exit
}
//dirty = false // these events don't invalidate state
case _ = <-TimeAfterOrBlock(obj.ctimeout):
obj.SetConvergedState(resConvergedTimeout)
obj.converged <- true
continue
}
// do all our event sending all together to avoid duplicate msgs
if send {
send = false
// only invalid state on certain types of events
if dirty {
dirty = false
obj.isStateOK = false // something made state dirty
}
Process(obj) // XXX: rename this function
}
}
}
func (obj *FileRes) HashSHA256fromContent() string {
if obj.sha256sum != "" { // return if already computed
return obj.sha256sum
}
hash := sha256.New()
hash.Write([]byte(obj.Content))
obj.sha256sum = hex.EncodeToString(hash.Sum(nil))
return obj.sha256sum
}
func (obj *FileRes) FileHashSHA256Check() (bool, error) {
if PathIsDir(obj.GetPath()) { // assert
log.Fatal("This should only be called on a File resource.")
}
// run a diff, and return true if it needs changing
hash := sha256.New()
f, err := os.Open(obj.GetPath())
if err != nil {
if e, ok := err.(*os.PathError); ok && (e.Err.(syscall.Errno) == syscall.ENOENT) {
return false, nil // no "error", file is just absent
}
return false, err
}
defer f.Close()
if _, err := io.Copy(hash, f); err != nil {
return false, err
}
sha256sum := hex.EncodeToString(hash.Sum(nil))
//log.Printf("sha256sum: %v", sha256sum)
if obj.HashSHA256fromContent() == sha256sum {
return true, nil
}
return false, nil
}
func (obj *FileRes) FileApply() error {
if PathIsDir(obj.GetPath()) {
log.Fatal("This should only be called on a File resource.")
}
if obj.State == "absent" {
log.Printf("About to remove: %v", obj.GetPath())
err := os.Remove(obj.GetPath())
return err // either nil or not, for success or failure
}
f, err := os.Create(obj.GetPath())
if err != nil {
return nil
}
defer f.Close()
_, err = io.WriteString(f, obj.Content)
if err != nil {
return err
}
return nil // success
}
func (obj *FileRes) CheckApply(apply bool) (stateok bool, err error) {
log.Printf("%v[%v]: CheckApply(%t)", obj.Kind(), obj.GetName(), apply)
if obj.isStateOK { // cache the state
return true, nil
}
if _, err = os.Stat(obj.GetPath()); os.IsNotExist(err) {
// no such file or directory
if obj.State == "absent" {
// missing file should be missing, phew :)
obj.isStateOK = true
return true, nil
}
}
err = nil // reset
// FIXME: add file mode check here...
if PathIsDir(obj.GetPath()) {
log.Fatal("Not implemented!") // XXX
} else {
ok, err := obj.FileHashSHA256Check()
if err != nil {
return false, err
}
if ok {
obj.isStateOK = true
return true, nil
}
// if no err, but !ok, then we continue on...
}
// state is not okay, no work done, exit, but without error
if !apply {
return false, nil
}
// apply portion
log.Printf("%v[%v]: Apply", obj.Kind(), obj.GetName())
if PathIsDir(obj.GetPath()) {
log.Fatal("Not implemented!") // XXX
} else {
err = obj.FileApply()
if err != nil {
return false, err
}
}
obj.isStateOK = true
return false, nil // success
}
type FileUUID struct {
BaseUUID
path string
}
// if and only if they are equivalent, return true
// if they are not equivalent, return false
func (obj *FileUUID) IFF(uuid ResUUID) bool {
res, ok := uuid.(*FileUUID)
if !ok {
return false
}
return obj.path == res.path
}
type FileResAutoEdges struct {
data []ResUUID
pointer int
found bool
}
func (obj *FileResAutoEdges) Next() []ResUUID {
if obj.found {
log.Fatal("Shouldn't be called anymore!")
}
if len(obj.data) == 0 { // check length for rare scenarios
return nil
}
value := obj.data[obj.pointer]
obj.pointer += 1
return []ResUUID{value} // we return one, even though api supports N
}
// get results of the earlier Next() call, return if we should continue!
func (obj *FileResAutoEdges) Test(input []bool) bool {
// if there aren't any more remaining
if len(obj.data) <= obj.pointer {
return false
}
if obj.found { // already found, done!
return false
}
if len(input) != 1 { // in case we get given bad data
log.Fatal("Expecting a single value!")
}
if input[0] { // if a match is found, we're done!
obj.found = true // no more to find!
return false
}
return true // keep going
}
// generate a simple linear sequence of each parent directory from bottom up!
func (obj *FileRes) AutoEdges() AutoEdge {
var data []ResUUID // store linear result chain here...
values := PathSplitFullReversed(obj.GetPath()) // build it
_, values = values[0], values[1:] // get rid of first value which is me!
for _, x := range values {
var reversed bool = true // cheat by passing a pointer
data = append(data, &FileUUID{
BaseUUID: BaseUUID{
name: obj.GetName(),
kind: obj.Kind(),
reversed: &reversed,
},
path: x, // what matters
}) // build list
}
return &FileResAutoEdges{
data: data,
pointer: 0,
found: false,
}
}
func (obj *FileRes) GetUUIDs() []ResUUID {
x := &FileUUID{
BaseUUID: BaseUUID{name: obj.GetName(), kind: obj.Kind()},
path: obj.GetPath(),
}
return []ResUUID{x}
}
func (obj *FileRes) Compare(res Res) bool {
switch res.(type) {
case *FileRes:
res := res.(*FileRes)
if obj.Name != res.Name {
return false
}
if obj.GetPath() != res.Path {
return false
}
if obj.Content != res.Content {
return false
}
if obj.State != res.State {
return false
}
default:
return false
}
return true
}