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Diffstat (limited to 'pkg/state/map.go')
| -rw-r--r-- | pkg/state/map.go | 232 |
1 files changed, 0 insertions, 232 deletions
diff --git a/pkg/state/map.go b/pkg/state/map.go deleted file mode 100644 index 4f3ebb0da..000000000 --- a/pkg/state/map.go +++ /dev/null @@ -1,232 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package state - -import ( - "context" - "fmt" - "reflect" - "sort" - "sync" - - pb "gvisor.dev/gvisor/pkg/state/object_go_proto" -) - -// entry is a single map entry. -type entry struct { - name string - object *pb.Object -} - -// internalMap is the internal Map state. -// -// These are recycled via a pool to avoid churn. -type internalMap struct { - // es is encodeState. - es *encodeState - - // ds is decodeState. - ds *decodeState - - // os is current object being decoded. - // - // This will always be nil during encode. - os *objectState - - // data stores the encoded values. - data []entry -} - -var internalMapPool = sync.Pool{ - New: func() interface{} { - return new(internalMap) - }, -} - -// newInternalMap returns a cached map. -func newInternalMap(es *encodeState, ds *decodeState, os *objectState) *internalMap { - m := internalMapPool.Get().(*internalMap) - m.es = es - m.ds = ds - m.os = os - if m.data != nil { - m.data = m.data[:0] - } - return m -} - -// Map is a generic state container. -// -// This is the object passed to Save and Load in order to store their state. -// -// Detailed documentation is available in individual methods. -type Map struct { - *internalMap -} - -// Save adds the given object to the map. -// -// You should pass always pointers to the object you are saving. For example: -// -// type X struct { -// A int -// B *int -// } -// -// func (x *X) Save(m Map) { -// m.Save("A", &x.A) -// m.Save("B", &x.B) -// } -// -// func (x *X) Load(m Map) { -// m.Load("A", &x.A) -// m.Load("B", &x.B) -// } -func (m Map) Save(name string, objPtr interface{}) { - m.save(name, reflect.ValueOf(objPtr).Elem(), ".%s") -} - -// SaveValue adds the given object value to the map. -// -// This should be used for values where pointers are not available, or casts -// are required during Save/Load. -// -// For example, if we want to cast external package type P.Foo to int64: -// -// type X struct { -// A P.Foo -// } -// -// func (x *X) Save(m Map) { -// m.SaveValue("A", int64(x.A)) -// } -// -// func (x *X) Load(m Map) { -// m.LoadValue("A", new(int64), func(x interface{}) { -// x.A = P.Foo(x.(int64)) -// }) -// } -func (m Map) SaveValue(name string, obj interface{}) { - m.save(name, reflect.ValueOf(obj), ".(value %s)") -} - -// save is helper for the above. It takes the name of value to save the field -// to, the field object (obj), and a format string that specifies how the -// field's saving logic is dispatched from the struct (normal, value, etc.). The -// format string should expect one string parameter, which is the name of the -// field. -func (m Map) save(name string, obj reflect.Value, format string) { - if m.es == nil { - // Not currently encoding. - m.Failf("no encode state for %q", name) - } - - // Attempt the encode. - // - // These are sorted at the end, after all objects are added and will be - // sorted and checked for duplicates (see encodeStruct). - m.data = append(m.data, entry{ - name: name, - object: m.es.encodeObject(obj, false, format, name), - }) -} - -// Load loads the given object from the map. -// -// See Save for an example. -func (m Map) Load(name string, objPtr interface{}) { - m.load(name, reflect.ValueOf(objPtr), false, nil, ".%s") -} - -// LoadWait loads the given objects from the map, and marks it as requiring all -// AfterLoad executions to complete prior to running this object's AfterLoad. -// -// See Save for an example. -func (m Map) LoadWait(name string, objPtr interface{}) { - m.load(name, reflect.ValueOf(objPtr), true, nil, ".(wait %s)") -} - -// LoadValue loads the given object value from the map. -// -// See SaveValue for an example. -func (m Map) LoadValue(name string, objPtr interface{}, fn func(interface{})) { - o := reflect.ValueOf(objPtr) - m.load(name, o, true, func() { fn(o.Elem().Interface()) }, ".(value %s)") -} - -// load is helper for the above. It takes the name of value to load the field -// from, the target field pointer (objPtr), whether load completion of the -// struct depends on the field's load completion (wait), the load completion -// logic (fn), and a format string that specifies how the field's loading logic -// is dispatched from the struct (normal, wait, value, etc.). The format string -// should expect one string parameter, which is the name of the field. -func (m Map) load(name string, objPtr reflect.Value, wait bool, fn func(), format string) { - if m.ds == nil { - // Not currently decoding. - m.Failf("no decode state for %q", name) - } - - // Find the object. - // - // These are sorted up front (and should appear in the state file - // sorted as well), so we can do a binary search here to ensure that - // large structs don't behave badly. - i := sort.Search(len(m.data), func(i int) bool { - return m.data[i].name >= name - }) - if i >= len(m.data) || m.data[i].name != name { - // There is no data for this name? - m.Failf("no data found for %q", name) - } - - // Perform the decode. - m.ds.decodeObject(m.os, objPtr.Elem(), m.data[i].object, format, name) - if wait { - // Mark this individual object a blocker. - m.ds.waitObject(m.os, m.data[i].object, fn) - } -} - -// Failf fails the save or restore with the provided message. Processing will -// stop after calling Failf, as the state package uses a panic & recover -// mechanism for state errors. You should defer any cleanup required. -func (m Map) Failf(format string, args ...interface{}) { - panic(fmt.Errorf(format, args...)) -} - -// AfterLoad schedules a function execution when all objects have been allocated -// and their automated loading and customized load logic have been executed. fn -// will not be executed until all of current object's dependencies' AfterLoad() -// logic, if exist, have been executed. -func (m Map) AfterLoad(fn func()) { - if m.ds == nil { - // Not currently decoding. - m.Failf("not decoding") - } - - // Queue the local callback; this will execute when all of the above - // data dependencies have been cleared. - m.os.callbacks = append(m.os.callbacks, fn) -} - -// Context returns the current context object. -func (m Map) Context() context.Context { - if m.es != nil { - return m.es.ctx - } else if m.ds != nil { - return m.ds.ctx - } - return context.Background() // No context. -} |