go.etcd.io/etcd@v3.3.27+incompatible/etcdserver/v2_server.go (about)

     1  // Copyright 2016 The etcd Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package etcdserver
    16  
    17  import (
    18  	"context"
    19  	"time"
    20  
    21  	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
    22  	"github.com/coreos/etcd/store"
    23  )
    24  
    25  type RequestV2 pb.Request
    26  
    27  type RequestV2Handler interface {
    28  	Post(ctx context.Context, r *RequestV2) (Response, error)
    29  	Put(ctx context.Context, r *RequestV2) (Response, error)
    30  	Delete(ctx context.Context, r *RequestV2) (Response, error)
    31  	QGet(ctx context.Context, r *RequestV2) (Response, error)
    32  	Get(ctx context.Context, r *RequestV2) (Response, error)
    33  	Head(ctx context.Context, r *RequestV2) (Response, error)
    34  }
    35  
    36  type reqV2HandlerEtcdServer struct {
    37  	reqV2HandlerStore
    38  	s *EtcdServer
    39  }
    40  
    41  type reqV2HandlerStore struct {
    42  	store   store.Store
    43  	applier ApplierV2
    44  }
    45  
    46  func NewStoreRequestV2Handler(s store.Store, applier ApplierV2) RequestV2Handler {
    47  	return &reqV2HandlerStore{s, applier}
    48  }
    49  
    50  func (a *reqV2HandlerStore) Post(ctx context.Context, r *RequestV2) (Response, error) {
    51  	return a.applier.Post(r), nil
    52  }
    53  
    54  func (a *reqV2HandlerStore) Put(ctx context.Context, r *RequestV2) (Response, error) {
    55  	return a.applier.Put(r), nil
    56  }
    57  
    58  func (a *reqV2HandlerStore) Delete(ctx context.Context, r *RequestV2) (Response, error) {
    59  	return a.applier.Delete(r), nil
    60  }
    61  
    62  func (a *reqV2HandlerStore) QGet(ctx context.Context, r *RequestV2) (Response, error) {
    63  	return a.applier.QGet(r), nil
    64  }
    65  
    66  func (a *reqV2HandlerStore) Get(ctx context.Context, r *RequestV2) (Response, error) {
    67  	if r.Wait {
    68  		wc, err := a.store.Watch(r.Path, r.Recursive, r.Stream, r.Since)
    69  		return Response{Watcher: wc}, err
    70  	}
    71  	ev, err := a.store.Get(r.Path, r.Recursive, r.Sorted)
    72  	return Response{Event: ev}, err
    73  }
    74  
    75  func (a *reqV2HandlerStore) Head(ctx context.Context, r *RequestV2) (Response, error) {
    76  	ev, err := a.store.Get(r.Path, r.Recursive, r.Sorted)
    77  	return Response{Event: ev}, err
    78  }
    79  
    80  func (a *reqV2HandlerEtcdServer) Post(ctx context.Context, r *RequestV2) (Response, error) {
    81  	return a.processRaftRequest(ctx, r)
    82  }
    83  
    84  func (a *reqV2HandlerEtcdServer) Put(ctx context.Context, r *RequestV2) (Response, error) {
    85  	return a.processRaftRequest(ctx, r)
    86  }
    87  
    88  func (a *reqV2HandlerEtcdServer) Delete(ctx context.Context, r *RequestV2) (Response, error) {
    89  	return a.processRaftRequest(ctx, r)
    90  }
    91  
    92  func (a *reqV2HandlerEtcdServer) QGet(ctx context.Context, r *RequestV2) (Response, error) {
    93  	return a.processRaftRequest(ctx, r)
    94  }
    95  
    96  func (a *reqV2HandlerEtcdServer) processRaftRequest(ctx context.Context, r *RequestV2) (Response, error) {
    97  	data, err := ((*pb.Request)(r)).Marshal()
    98  	if err != nil {
    99  		return Response{}, err
   100  	}
   101  	ch := a.s.w.Register(r.ID)
   102  
   103  	start := time.Now()
   104  	a.s.r.Propose(ctx, data)
   105  	proposalsPending.Inc()
   106  	defer proposalsPending.Dec()
   107  
   108  	select {
   109  	case x := <-ch:
   110  		resp := x.(Response)
   111  		return resp, resp.Err
   112  	case <-ctx.Done():
   113  		proposalsFailed.Inc()
   114  		a.s.w.Trigger(r.ID, nil) // GC wait
   115  		return Response{}, a.s.parseProposeCtxErr(ctx.Err(), start)
   116  	case <-a.s.stopping:
   117  	}
   118  	return Response{}, ErrStopped
   119  }
   120  
   121  func (s *EtcdServer) Do(ctx context.Context, r pb.Request) (Response, error) {
   122  	r.ID = s.reqIDGen.Next()
   123  	h := &reqV2HandlerEtcdServer{
   124  		reqV2HandlerStore: reqV2HandlerStore{
   125  			store:   s.store,
   126  			applier: s.applyV2,
   127  		},
   128  		s: s,
   129  	}
   130  	rp := &r
   131  	resp, err := ((*RequestV2)(rp)).Handle(ctx, h)
   132  	resp.Term, resp.Index = s.Term(), s.Index()
   133  	return resp, err
   134  }
   135  
   136  // Handle interprets r and performs an operation on s.store according to r.Method
   137  // and other fields. If r.Method is "POST", "PUT", "DELETE", or a "GET" with
   138  // Quorum == true, r will be sent through consensus before performing its
   139  // respective operation. Do will block until an action is performed or there is
   140  // an error.
   141  func (r *RequestV2) Handle(ctx context.Context, v2api RequestV2Handler) (Response, error) {
   142  	if r.Method == "GET" && r.Quorum {
   143  		r.Method = "QGET"
   144  	}
   145  	switch r.Method {
   146  	case "POST":
   147  		return v2api.Post(ctx, r)
   148  	case "PUT":
   149  		return v2api.Put(ctx, r)
   150  	case "DELETE":
   151  		return v2api.Delete(ctx, r)
   152  	case "QGET":
   153  		return v2api.QGet(ctx, r)
   154  	case "GET":
   155  		return v2api.Get(ctx, r)
   156  	case "HEAD":
   157  		return v2api.Head(ctx, r)
   158  	}
   159  	return Response{}, ErrUnknownMethod
   160  }
   161  
   162  func (r *RequestV2) String() string {
   163  	rpb := pb.Request(*r)
   164  	return rpb.String()
   165  }