VOL-3121 - Separated ports from devices.
Similar to flows/groups/meters/logical ports.
Also added ListDevicePorts and GetDevicePort to the adapter API.
Also removed unused `// +build integration` tests.
Change-Id: I586adb9f46a249c9430d4205ef5db2d105dbbe06
diff --git a/rw_core/core/device/port/loader.go b/rw_core/core/device/port/loader.go
new file mode 100644
index 0000000..479695a
--- /dev/null
+++ b/rw_core/core/device/port/loader.go
@@ -0,0 +1,187 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * 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 port
+
+import (
+ "context"
+ "fmt"
+ "sync"
+
+ "github.com/opencord/voltha-go/db/model"
+ "github.com/opencord/voltha-lib-go/v3/pkg/log"
+ "github.com/opencord/voltha-protos/v3/go/voltha"
+ "google.golang.org/grpc/codes"
+ "google.golang.org/grpc/status"
+)
+
+// Loader hides all low-level locking & synchronization related to port state updates
+type Loader struct {
+ dbProxy *model.Proxy
+ // this lock protects the ports map, it does not protect individual ports
+ lock sync.RWMutex
+ ports map[uint32]*chunk
+}
+
+// chunk keeps a port and the lock for this port
+type chunk struct {
+ // this lock is used to synchronize all access to the port, and also to the "deleted" variable
+ lock sync.Mutex
+ deleted bool
+
+ port *voltha.Port
+}
+
+func NewLoader(dbProxy *model.Proxy) *Loader {
+ return &Loader{
+ dbProxy: dbProxy,
+ ports: make(map[uint32]*chunk),
+ }
+}
+
+// Load queries existing ports from the kv,
+// and should only be called once when first created.
+func (loader *Loader) Load(ctx context.Context) {
+ loader.lock.Lock()
+ defer loader.lock.Unlock()
+
+ var ports []*voltha.Port
+ if err := loader.dbProxy.List(ctx, &ports); err != nil {
+ logger.Errorw(ctx, "failed-to-list-ports-from-cluster-data-proxy", log.Fields{"error": err})
+ return
+ }
+ for _, port := range ports {
+ loader.ports[port.PortNo] = &chunk{port: port}
+ }
+}
+
+// LockOrCreate locks this port if it exists, or creates a new port if it does not.
+// In the case of port creation, the provided "port" must not be modified afterwards.
+func (loader *Loader) LockOrCreate(ctx context.Context, port *voltha.Port) (*Handle, bool, error) {
+ // try to use read lock instead of full lock if possible
+ if handle, have := loader.Lock(port.PortNo); have {
+ return handle, false, nil
+ }
+
+ loader.lock.Lock()
+ entry, have := loader.ports[port.PortNo]
+ if !have {
+ entry := &chunk{port: port}
+ loader.ports[port.PortNo] = entry
+ entry.lock.Lock()
+ loader.lock.Unlock()
+
+ if err := loader.dbProxy.Set(ctx, fmt.Sprint(port.PortNo), port); err != nil {
+ // revert the map
+ loader.lock.Lock()
+ delete(loader.ports, port.PortNo)
+ loader.lock.Unlock()
+
+ entry.deleted = true
+ entry.lock.Unlock()
+ return nil, false, err
+ }
+ return &Handle{loader: loader, chunk: entry}, true, nil
+ }
+ loader.lock.Unlock()
+
+ entry.lock.Lock()
+ if entry.deleted {
+ entry.lock.Unlock()
+ return loader.LockOrCreate(ctx, port)
+ }
+ return &Handle{loader: loader, chunk: entry}, false, nil
+}
+
+// Lock acquires the lock for this port, and returns a handle which can be used to access the port until it's unlocked.
+// This handle ensures that the port cannot be accessed if the lock is not held.
+// Returns false if the port is not present.
+// TODO: consider accepting a ctx and aborting the lock attempt on cancellation
+func (loader *Loader) Lock(id uint32) (*Handle, bool) {
+ loader.lock.RLock()
+ entry, have := loader.ports[id]
+ loader.lock.RUnlock()
+
+ if !have {
+ return nil, false
+ }
+
+ entry.lock.Lock()
+ if entry.deleted {
+ entry.lock.Unlock()
+ return loader.Lock(id)
+ }
+ return &Handle{loader: loader, chunk: entry}, true
+}
+
+// Handle is allocated for each Lock() call, all modifications are made using it, and it is invalidated by Unlock()
+// This enforces correct Lock()-Usage()-Unlock() ordering.
+type Handle struct {
+ loader *Loader
+ chunk *chunk
+}
+
+// GetReadOnly returns an *voltha.Port which MUST NOT be modified externally, but which is safe to keep indefinitely
+func (h *Handle) GetReadOnly() *voltha.Port {
+ return h.chunk.port
+}
+
+// Update updates an existing port in the kv.
+// The provided "port" must not be modified afterwards.
+func (h *Handle) Update(ctx context.Context, port *voltha.Port) error {
+ if err := h.loader.dbProxy.Set(ctx, fmt.Sprint(port.PortNo), port); err != nil {
+ return status.Errorf(codes.Internal, "failed-update-port-%v: %s", port.PortNo, err)
+ }
+ h.chunk.port = port
+ return nil
+}
+
+// Delete removes the device from the kv
+func (h *Handle) Delete(ctx context.Context) error {
+ if err := h.loader.dbProxy.Remove(ctx, fmt.Sprint(h.chunk.port.PortNo)); err != nil {
+ return fmt.Errorf("couldnt-delete-port-from-store-%v", h.chunk.port.PortNo)
+ }
+ h.chunk.deleted = true
+
+ h.loader.lock.Lock()
+ delete(h.loader.ports, h.chunk.port.PortNo)
+ h.loader.lock.Unlock()
+
+ h.Unlock()
+ return nil
+}
+
+// Unlock releases the lock on the port
+func (h *Handle) Unlock() {
+ if h.chunk != nil {
+ h.chunk.lock.Unlock()
+ h.chunk = nil // attempting to access the port through this handle in future will panic
+ }
+}
+
+// ListIDs returns a snapshot of all the managed port IDs
+// TODO: iterating through ports safely is expensive now, since all ports are stored & locked separately
+// should avoid this where possible
+func (loader *Loader) ListIDs() map[uint32]struct{} {
+ loader.lock.RLock()
+ defer loader.lock.RUnlock()
+ // copy the IDs so caller can safely iterate
+ ret := make(map[uint32]struct{}, len(loader.ports))
+ for id := range loader.ports {
+ ret[id] = struct{}{}
+ }
+ return ret
+}