Class: Gcloud::Datastore::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/gcloud/datastore/connection.rb

Overview

Represent the HTTP connection to the Datastore, as well as the Datastore API calls.

This class only deals with Protocol Buffer objects, and is not part of the public API.

Constant Summary collapse

API_VERSION = 
"v1beta2"
API_URL = 
"https://www.googleapis.com"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(dataset_id, credentials) ⇒ Connection

Create a new Connection instance.

Examples:

conn = Gcloud::Datastore.Connection.new "my-todo-project",
  Gcloud::Datastore::Credentials.new("/path/to/keyfile.json")



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# File 'lib/gcloud/datastore/connection.rb', line 47

def initialize dataset_id, credentials
  @dataset_id = dataset_id
  @credentials = credentials
end

Instance Attribute Details

#credentials ⇒ Object

The Credentials object for signing HTTP requests.



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# File 'lib/gcloud/datastore/connection.rb', line 38

def credentials
  @credentials
end

#dataset_id ⇒ Object

The project/dataset_id connected to.



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# File 'lib/gcloud/datastore/connection.rb', line 34

def dataset_id
  @dataset_id
end

#default_http_headers ⇒ Object

The default HTTP headers to be sent on all API calls.



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# File 'lib/gcloud/datastore/connection.rb', line 135

def default_http_headers
  @default_http_headers ||= {
    "User-Agent"   => "gcloud-node/#{Gcloud::VERSION}",
    "Content-Type" => "application/x-protobuf" }
end

#http ⇒ Object

The HTTP object that makes calls to Datastore. This must be a Faraday object.



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# File 'lib/gcloud/datastore/connection.rb', line 147

def http
  @http ||= Faraday.new url: http_host
end

Instance Method Details

#allocate_ids(*incomplete_keys) ⇒ Object

Allocate IDs for incomplete keys. (This is useful for referencing an entity before it is inserted.)



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# File 'lib/gcloud/datastore/connection.rb', line 55

def allocate_ids *incomplete_keys
  allocate_ids = Proto::AllocateIdsRequest.new.tap do |ai|
    ai.key = incomplete_keys
  end

  rpc_response = rpc("allocateIds", allocate_ids)
  Proto::AllocateIdsResponse.decode rpc_response
end

#begin_transaction ⇒ Object

Begin a new transaction.



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# File 'lib/gcloud/datastore/connection.rb', line 100

def begin_transaction
  tx_request = Proto::BeginTransactionRequest.new

  response_rpc = rpc "beginTransaction", tx_request
  Proto::BeginTransactionResponse.decode response_rpc
end

#commit(mutation, transaction = nil) ⇒ Object

Commit a transaction, optionally creating, deleting or modifying some entities.



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# File 'lib/gcloud/datastore/connection.rb', line 110

def commit mutation, transaction = nil
  mode = Proto::CommitRequest::Mode::NON_TRANSACTIONAL
  mode = Proto::CommitRequest::Mode::TRANSACTIONAL if transaction

  commit = Proto::CommitRequest.new.tap do |c|
    c.mutation = mutation
    c.mode = mode
    c.transaction = transaction
  end

  Proto::CommitResponse.decode rpc("commit", commit)
end

#http_host ⇒ Object

The Datastore API URL.



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# File 'lib/gcloud/datastore/connection.rb', line 156

def http_host
  @http_host || ENV["DATASTORE_HOST"] || API_URL
end

#http_host=(new_http_host) ⇒ Object

Update the Datastore API URL.



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# File 'lib/gcloud/datastore/connection.rb', line 162

def http_host= new_http_host
  @http = nil # Reset the HTTP connection when host is set
  @http_host = new_http_host
end

#inspect ⇒ Object 



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# File 'lib/gcloud/datastore/connection.rb', line 167

def inspect
  "#{self.class}(#{@dataset_id})"
end

#lookup(*keys, consistency: nil, transaction: nil) ⇒ Object

Look up entities by keys.



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# File 'lib/gcloud/datastore/connection.rb', line 66

def lookup *keys, consistency: nil, transaction: nil
  lookup = Proto::LookupRequest.new key: keys
  if consistency == :eventual
    lookup.read_options = Proto::ReadOptions.new(read_consistency: 2)
  elsif consistency == :strong
    lookup.read_options = Proto::ReadOptions.new(read_consistency: 1)
  elsif transaction
    lookup.read_options = Proto::ReadOptions.new(
      transaction: transaction)
  end

  Proto::LookupResponse.decode rpc("lookup", lookup)
end

#rollback(transaction) ⇒ Object

Roll back a transaction.



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# File 'lib/gcloud/datastore/connection.rb', line 125

def rollback transaction
  rollback = Proto::RollbackRequest.new.tap do |r|
    r.transaction = transaction
  end

  Proto::RollbackResponse.decode rpc("rollback", rollback)
end

#run_query(query, partition = nil, consistency: nil, transaction: nil) ⇒ Object

Query for entities.



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# File 'lib/gcloud/datastore/connection.rb', line 81

def run_query query, partition = nil, consistency: nil, transaction: nil
  run_query = Proto::RunQueryRequest.new.tap do |rq|
    rq.query = query
    rq.partition_id = partition if partition
  end
  if consistency == :eventual
    run_query.read_options = Proto::ReadOptions.new(read_consistency: 2)
  elsif consistency == :strong
    run_query.read_options = Proto::ReadOptions.new(read_consistency: 1)
  elsif transaction
    run_query.read_options = Proto::ReadOptions.new(
      transaction: transaction)
  end

  Proto::RunQueryResponse.decode rpc("runQuery", run_query)
end