Commit Graph

4 Commits

Author SHA1 Message Date
Christopher Goes bf16d6453c
Address PR comments 2018-05-07 22:12:26 +02:00
Emmanuel T Odeke 5d12e1eb46
remotedb: a client package implementing the db.DB interface
Simplified the abstractions to remotedb, a package that
allows clients to use whatever database they can in client
code without having to switch out their code e.g
```go
client, err := remotedb.NewInsecure(":9888")
...
// Just like they'd initialize locally
in := &remotedb.Init{
  Name: "test-remote-db",
  Type: "leveldb",
  Dir: "/tmp/dbs",
}

if err := client.InitRemote(in); err != nil {
    log.Fatalf("Failed to initialize the database")
}

v1 := client.Get(k1)
client.Set(k9, dog)

for itr := client.Iterator(a1, z1); itr.Valid(); itr.Next() {
  k, v := itr.Key(), itr.Value()
  dom := itr.Domain()
  ...
}
```
2018-05-07 22:00:38 +02:00
Emmanuel T Odeke 1260b75f63
grpcdb: Better readability for docs and constructor names
* Added some docs for NewClient, BindServer, *server.Init
* Security level clarified, whether "secure" for https
or "insecure" for non-https gRPC connections.
2018-05-07 22:00:38 +02:00
Emmanuel T Odeke 11bee6194a
DB as a service
Fixes https://github.com/tendermint/tendermint/issues/1162

Databases as a service!

Can now access Databases as a remote service
via gRPC for performance and easy deployment.

The caveat is that each service is stateful in regards to
the DB i.e. each unique service uses only one unique DB
but nonetheless multiple clients can access it.

A full standalone example

```go
package main

import (
  "bytes"
  "context"
  "log"

  grpcdb "github.com/tendermint/tmlibs/grpcdb"
  protodb "github.com/tendermint/tmlibs/proto"
)

func main() {
  addr := ":8998"
  go func() {
    if err := grpcdb.BindRemoteDBServer(addr); err != nil {
      log.Fatalf("BindRemoteDBServer: %v", err)
    }
  }()

  client, err := grpcdb.NewClient(addr, false)
  if err != nil {
    log.Fatalf("Failed to create grpcDB client: %v", err)
  }

  ctx := context.Background()
  // 1. Initialize the DB
  in := &protodb.Init{
    Type: "leveldb",
    Name: "grpc-uno-test",
    Dir:  ".",
  }
  if _, err := client.Init(ctx, in); err != nil {
    log.Fatalf("Init error: %v", err)
  }

  // 2. Now it can be used!
  query1 := &protodb.Entity{Key: []byte("Project"), Value:
[]byte("Tmlibs-on-gRPC")}
  if _, err := client.SetSync(ctx, query1); err != nil {
    log.Fatalf("SetSync err: %v", err)
  }

  query2 := &protodb.Entity{Key: []byte("Project")}
  read, err := client.Get(ctx, query2)
  if err != nil {
    log.Fatalf("Get err: %v", err)
  }
  if g, w := read.Value, []byte("Tmlibs-on-gRPC"); !bytes.Equal(g, w) {
    log.Fatalf("got= (%q ==> % X)\nwant=(%q ==> % X)", g, g, w, w)
  }
}
```
2018-05-07 22:00:33 +02:00