This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (roachjs) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
This client is a port from the original Golang client.
Internally it's is more or less the same, but this driver provides a friendlier javascript interface.
// You should prepare your queries and send them in a single batch// For optimal performancevar c = client.prepare()// This callback will be the first to be executed
c.get("sample_key",function(err, value, res){if(err)throw err
// Do something...})
c.get("sample_key2",function(err, value, res){if(err)throw err
// Do something...})
c.put("some_key","some_value",function(err){if(err)throw err
// Do something})// The flush callback is the last one to be called
c.flush(function(err, res){if(err)throw err
console.log('Sucessfuly flushed %d queries.', res.responses.length)})
Advanced client usage II (Transactions)
var opts ={name:"transaction example",}var errNoApples =newError('Insufficient apples!')vartransaction=function(txn, commit, abort){
txn.get("applesInStock",function(err, value, res){if(err || applesInStock.err){returnabort(err)}var dispatch =5var inStock =parseInt(applesInStock.value)if(inStock < dispatch){returnabort(errNoApples)}// Upgrade for a prepared client
txn = txn.prepare()
txn.increment("applesInStock",-dispatch)
txn.increment("applesInRoute",+dispatch)// Commit automatically flushescommit()})}
client.runTransaction(opts, transaction,function(err, res){if(err === errNoApples){// Alert user there are no more apples...}elseif(err){// Transaction failed...}else{// Transaction commited...}})
ConditionalPut sets the value for a key if the existing value matches the ifValue.
Specifying an empty or null ifValue means the entry must not yet exist.
client.contains("john",function(err, exists, res){if(exists ===true){// john exists in the datastore}})
client.increment(key, increment, callback)
Increment increments the value at the specified key by some increment value.
Once called for a key, Put & Get will return errors; only Increment will continue to be a valid command.
The value must be deleted before it can be reset using Put.
Parameters
name
type
description
key
string
increment
integer
callback
callback
function(err, newValue, res) {}
Callback
name
type
description
err
Error()
newValue
integer
the new value for this counter, after the increment operation
Return you a new prepared client. It has all the methods from the original client.
Read Advanced client usage II to understand how to use this client.
You should always use this client when sending in multiple queries, this will batch them together in a single request.
var c = client.prepare()
c.get("key",function(err, value, res){// Do something...})
c.get("key2",function(err, value, res){// Do something...})
c.put("key3","value",function(err, res){// Do something...})
c.flush()
client.flush(callback)
Flush the prepared queries buffer, and send it as a batch request.
RunTransaction executes a retryable transaction function in
the context of a distributed transaction. The transaction is
automatically aborted if retryable function returns any error aside from
recoverable internal errors, and is automatically committed otherwise.
retryable should have no side effects which could cause problems in the event
it must be run more than once. The opts contains transaction settings.
The res argument contains the full database response, each database command can
contain a different set of properties. This document will try to state some of the possible properties.
Properties
property
type
description
timestamp
integer
timestamp of the returned entry
wall_time
integer
timestamp of when the read or write operation was performed
Transaction function
The transaction function is an retryable function, it may be
executed more than once. This function should never forget to
call commit or abort. Throwing an error inside this
function also aborts the transaction.