// FetchHash issues a FileContent RPC to read an entire file.
func FetchFromContentServer(client *rpc.Client, rpcName string, size int64, hash []byte) []byte {
chunkSize := 1 << 18
buf := bytes.NewBuffer(make([]byte, 0, size))
for {
req := &ContentRequest{
Hash: hash,
Start: buf.Len(),
End: buf.Len() + chunkSize,
}
rep := &ContentResponse{}
err := client.Call(rpcName, req, rep)
if err != nil && err != os.EOF {
log.Println("FileContent error:", err)
break
}
buf.Write(rep.Chunk)
if len(rep.Chunk) < chunkSize {
break
}
}
if buf.Len() < int(size) {
log.Fatal("Size mismatch", buf.Len(), size)
}
return buf.Bytes()
}
// FetchHash issues a FileContent RPC to read an entire file, and store into ContentCache.
//
// TODO - open a connection for this instead.
func FetchBetweenContentServers(client *rpc.Client, rpcName string, size int64, hash string,
dest *ContentCache) os.Error {
chunkSize := 1 << 18
output := dest.NewHashWriter()
written := 0
for {
req := &ContentRequest{
Hash: hash,
Start: written,
End: written + chunkSize,
}
rep := &ContentResponse{}
err := client.Call(rpcName, req, rep)
if err != nil {
log.Println("FileContent error:", err)
return err
}
n, err := output.Write(rep.Chunk)
written += n
if err != nil {
return err
}
if len(rep.Chunk) < chunkSize {
break
}
}
if written < int(size) {
return os.NewError(
fmt.Sprintf("Size mismatch %d != %d", written, size))
}
output.Close()
saved := string(output.hasher.Sum())
if saved != hash {
log.Fatalf("Corruption: savedHash %x != requested hash %x.", saved, hash)
}
return nil
}