README
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go-globe
This was an afternoon hack as an excuse to play with Go. Caveat emptor!
go-globe is a distributed dictionary backed by a replicated log such as etcd.
Good for things like:
- Managing dynamic configuration
- Storing data available cluster-wide
- Data or computational sharding
- Service discovery
- Other stuff!
Bad for things that require multiple nodes to write to the same key at a high rate, or really anything that needs super high throughput. This is mostly a convenience layer.
There is an abstraction interface for the log client so that any log can be used(ZooKeeper, consul, etc) but currently only etcd is implemented.
Currently it only supports string -> string key value pairs because of no generics in Go and I haven't explored other options for better value typing.
Interface
NewDict(keyspace string, logClient LogClient) *Dict
Creates a new globe.Dict and returns a pointer to it.
- keyspace: The keyspace in which to store data in the underlying log.
- logClient: The log client(see below)
Dict.Get(key string) (string, error)
Returns the local value at the given key.
Dict.Put(key string, value string) error
Updates the local value at the given key, updates the log, and returns any errors
NewEtcdClient(cluster []string) *EtcdClient
EtcdClient implements the LogClient interface.
- cluster: A list of host:port strings that represent the etcd cluster
Example
client := NewEtcdClient([]string{"http://127.0.0.1:4001"})
myDict, err := NewDict("example", client)
myDict.Put("foo", "bar") // ignoring any error
val := myDict.Get("foo") // val == "bar"
Running tests
Note that the tests assume a running etcd process at localhost:4001(the default) and that they are non-deterministic because of race conditions and sleeps and I just haven't made them better yet.
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
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Functions ¶
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Types ¶
type Dict ¶
type Dict struct {
// contains filtered or unexported fields
}
A Key-Value dictionary backed by an distributed log
func NewDict ¶
Constructs and returns a new dictionary. The returned dict will be populated with the latest snapshot of the log and automatically update the local copy of the data as it changes remotely.
func (*Dict) Close ¶
func (d *Dict) Close()
Close the dictionary. It will no longer respond to log updates
type EtcdClient ¶
type EtcdClient struct {
// contains filtered or unexported fields
}
Implements LogClient
func (*EtcdClient) Get ¶
func (e *EtcdClient) Get(path string) (*LogNode, error)
LogClient Implementation
func (*EtcdClient) PutDir ¶
func (e *EtcdClient) PutDir(path string) error
type LogClient ¶
type LogClient interface {
Get(path string) (*LogNode, error)
Put(path string, value string) error
PutDir(path string) error
Watch(path string, watcher chan *LogNode, closer chan bool)
}
Generic client interface used as a wrapper for the underyling log client. See etcd_client.go for example implementatino
Source Files