| // Copyright (C) 2015 The Android Open Source Project |
| // |
| // 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 database |
| |
| import ( |
| "fmt" |
| "reflect" |
| "sync" |
| |
| "android.googlesource.com/platform/tools/gpu/binary" |
| "android.googlesource.com/platform/tools/gpu/config" |
| "android.googlesource.com/platform/tools/gpu/log" |
| ) |
| |
| // NewInMemory builds a new in memory database. |
| func NewInMemory(buildContext interface{}) Database { |
| return &memory{ |
| records: map[binary.ID]*record{}, |
| buildContext: buildContext, |
| } |
| } |
| |
| type record struct { |
| value interface{} |
| err error |
| wait chan struct{} |
| } |
| |
| type memory struct { |
| mutex sync.Mutex |
| records map[binary.ID]*record |
| buildContext interface{} // The build context, user-defined. |
| } |
| |
| // Implements Database |
| func (d *memory) Store(id binary.ID, v interface{}, logger log.Logger) error { |
| d.mutex.Lock() |
| defer d.mutex.Unlock() |
| return d.store(id, v, logger) |
| } |
| |
| // store function must be called with a locked mutex |
| func (d *memory) store(id binary.ID, v interface{}, logger log.Logger) error { |
| r, got := d.records[id] |
| if !got { |
| d.records[id] = &record{value: v} |
| } else if config.DebugDatabaseVerify { |
| if !reflect.DeepEqual(v, r.value) { |
| return fmt.Errorf("Duplicate object id %v", id) |
| } |
| } |
| return nil |
| } |
| |
| // Implements Database |
| func (d *memory) Resolve(id binary.ID, logger log.Logger) (interface{}, error) { |
| d.mutex.Lock() |
| defer d.mutex.Unlock() |
| return d.resolve(id, logger) |
| } |
| |
| // load function must be called with a locked mutex |
| func (d *memory) resolve(id binary.ID, logger log.Logger) (interface{}, error) { |
| r, got := d.records[id] |
| if !got { |
| return nil, fmt.Errorf("Resource '%v' not found", id) |
| } |
| if r.err != nil { |
| return r.value, r.err |
| } |
| lazy, islazy := r.value.(Lazy) |
| if !islazy { |
| return r.value, r.err |
| } |
| // transform the id to get the lazy result id |
| lazyID := LazyOutputID(id) |
| if r.wait != nil { |
| // an in progress request, wait for it |
| d.mutex.Unlock() // unlock before waiting |
| <-r.wait |
| d.mutex.Lock() // relock after waiting |
| return d.resolve(lazyID, logger) |
| } |
| // must be a first time access to request |
| r.wait = make(chan struct{}) |
| value, err := func() (interface{}, error) { // func for defer scope |
| d.mutex.Unlock() // don't build under the lock |
| defer d.mutex.Lock() // relock after build |
| return lazy.BuildLazy(d.buildContext, d, logger) |
| }() |
| if err == nil { |
| err = d.store(lazyID, value, logger) |
| } |
| r.err = err |
| close(r.wait) |
| return value, r.err |
| } |
| |
| // Implements Database |
| func (d *memory) Contains(id binary.ID, logger log.Logger) (res bool) { |
| d.mutex.Lock() |
| defer d.mutex.Unlock() |
| _, got := d.records[id] |
| return got |
| } |