update

src/shardctrler/common.go

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+package shardctrler
+
+//
+// Shard controler: assigns shards to replication groups.
+//
+// RPC interface:
+// Join(servers) -- add a set of groups (gid -> server-list mapping).
+// Leave(gids) -- delete a set of groups.
+// Move(shard, gid) -- hand off one shard from current owner to gid.
+// Query(num) -> fetch Config # num, or latest config if num==-1.
+//
+// A Config (configuration) describes a set of replica groups, and the
+// replica group responsible for each shard. Configs are numbered. Config
+// #0 is the initial configuration, with no groups and all shards
+// assigned to group 0 (the invalid group).
+//
+// You will need to add fields to the RPC argument structs.
+//
+
+// The number of shards.
+const NShards = 10
+
+// A configuration -- an assignment of shards to groups.
+// Please don't change this.
+type Config struct {
+	Num    int              // config number
+	Shards [NShards]int     // shard -> gid
+	Groups map[int][]string // gid -> servers[]
+}
+
+const (
+	OK = "OK"
+)
+
+type Err string
+
+type JoinArgs struct {
+	Servers map[int][]string // new GID -> servers mappings
+}
+
+type JoinReply struct {
+	WrongLeader bool
+	Err         Err
+}
+
+type LeaveArgs struct {
+	GIDs []int
+}
+
+type LeaveReply struct {
+	WrongLeader bool
+	Err         Err
+}
+
+type MoveArgs struct {
+	Shard int
+	GID   int
+}
+
+type MoveReply struct {
+	WrongLeader bool
+	Err         Err
+}
+
+type QueryArgs struct {
+	Num int // desired config number
+}
+
+type QueryReply struct {
+	WrongLeader bool
+	Err         Err
+	Config      Config
+}