github.com/paybyphone/terraform@v0.9.5-0.20170613192930-9706042ddd51/state/remote/state.go (about)

     1  package remote
     2  
     3  import (
     4  	"bytes"
     5  	"sync"
     6  
     7  	"github.com/hashicorp/terraform/state"
     8  	"github.com/hashicorp/terraform/terraform"
     9  )
    10  
    11  // State implements the State interfaces in the state package to handle
    12  // reading and writing the remote state. This State on its own does no
    13  // local caching so every persist will go to the remote storage and local
    14  // writes will go to memory.
    15  type State struct {
    16  	mu sync.Mutex
    17  
    18  	Client Client
    19  
    20  	state, readState *terraform.State
    21  }
    22  
    23  // StateReader impl.
    24  func (s *State) State() *terraform.State {
    25  	s.mu.Lock()
    26  	defer s.mu.Unlock()
    27  
    28  	return s.state.DeepCopy()
    29  }
    30  
    31  // StateWriter impl.
    32  func (s *State) WriteState(state *terraform.State) error {
    33  	s.mu.Lock()
    34  	defer s.mu.Unlock()
    35  
    36  	s.state = state
    37  	return nil
    38  }
    39  
    40  // StateRefresher impl.
    41  func (s *State) RefreshState() error {
    42  	s.mu.Lock()
    43  	defer s.mu.Unlock()
    44  
    45  	payload, err := s.Client.Get()
    46  	if err != nil {
    47  		return err
    48  	}
    49  
    50  	// no remote state is OK
    51  	if payload == nil {
    52  		return nil
    53  	}
    54  
    55  	state, err := terraform.ReadState(bytes.NewReader(payload.Data))
    56  	if err != nil {
    57  		return err
    58  	}
    59  
    60  	s.state = state
    61  	s.readState = state
    62  	return nil
    63  }
    64  
    65  // StatePersister impl.
    66  func (s *State) PersistState() error {
    67  	s.mu.Lock()
    68  	defer s.mu.Unlock()
    69  
    70  	s.state.IncrementSerialMaybe(s.readState)
    71  
    72  	var buf bytes.Buffer
    73  	if err := terraform.WriteState(s.state, &buf); err != nil {
    74  		return err
    75  	}
    76  
    77  	return s.Client.Put(buf.Bytes())
    78  }
    79  
    80  // Lock calls the Client's Lock method if it's implemented.
    81  func (s *State) Lock(info *state.LockInfo) (string, error) {
    82  	s.mu.Lock()
    83  	defer s.mu.Unlock()
    84  
    85  	if c, ok := s.Client.(ClientLocker); ok {
    86  		return c.Lock(info)
    87  	}
    88  	return "", nil
    89  }
    90  
    91  // Unlock calls the Client's Unlock method if it's implemented.
    92  func (s *State) Unlock(id string) error {
    93  	s.mu.Lock()
    94  	defer s.mu.Unlock()
    95  
    96  	if c, ok := s.Client.(ClientLocker); ok {
    97  		return c.Unlock(id)
    98  	}
    99  	return nil
   100  }