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Added example file explaining the core features of the library.

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kallaspriit committed Jun 28, 2011
1 parent 677fc5a commit dc718b5400c837cb7ba4d6cde0c41ce72660fdf2
Showing with 617 additions and 96 deletions.
  1. +14 −0 Cassandra.php
  2. +266 −1 README
  3. +242 −0 example.php
  4. +95 −95 test/CassandraTest.php
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@@ -327,6 +327,16 @@ public function __construct(array $servers = array(), $autopack = true) {
$this->autopack = $autopack;
}
+ /**
+ * Creates a new named cassandra instance.
+ *
+ * The name can be used in {@see Cassandra::getInstance()} to fetch the
+ * named singleton anywhere in the project.
+ *
+ * @param array $servers List of seed servers to connect to
+ * @param type $name Name of the instance
+ * @return Cassandra New cassandra instance
+ */
public static function createInstance(array $servers, $name = 'main') {
self::$instances[$name] = new self($servers);
@@ -542,6 +552,10 @@ public function cf($name) {
return $this->columnFamilies[$name];
}
+ public function columnFamily($name) {
+ return $this->cf($name);
+ }
+
/**
* Requests some data as a single request string.
*
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267 README 100644 → 100755
@@ -1 +1,266 @@
-Cassandra PHP-based client library for managing and querying your Cassandra cluster
+Cassandra PHP-based client library for managing and querying your Cassandra
+cluster. It's a high-level library performing all the rather complex low-level
+lifting and providing a simple to learn and use interface.
+
+Features:
+- simple and intuitive interface
+- well covered with unit tests (>90%)
+- support for multiple server pools using named singletons
+- requires including a single file
+- uses reasonable defaults through-out
+- powerful syntax for querying data
+- enables managing keyspaces and column-families
+- automatic packing of datatypes using column metadata
+- retries failed queries using back-off strategy
+- built with performance in mind (caches schema description etc)
+- well documented API and a working example
+
+
+The following example covers most of what you need to know to use this library.
+It should work out-of-box on a machine with default cassandra setup running. The
+example file is contained in the download.
+
+<?php
+
+// the only file that needs including into your project
+require_once 'Cassandra.php';
+
+// list of seed servers to randomly connect to
+// all the parameters are optional and default to given values
+$servers = array(
+ array(
+ 'host' => '127.0.0.1',
+ 'port' => 9160,
+ 'use-framed-transport' => true,
+ 'send-timeout-ms' => 1000,
+ 'receive-timeout-ms' => 1000
+ )
+);
+
+// create a named singleton, the second parameter name defaults to "main"
+// you can have several named singletons with different server pools
+$cassandra = Cassandra::createInstance($servers);
+
+// at any point in code, you can get the named singleton instance, the name
+// again defaults to "main" so no need to define it if using single instance
+$cassandra2 = Cassandra::getInstance();
+
+// drop the example keyspace and ignore errors should it not exist
+try {
+ $cassandra->dropKeyspace('CassandraExample');
+} catch (Exception $e) {}
+
+
+// create a new keyspace, accepts extra parameters for replication options
+// normally you don't do it every time
+$cassandra->createKeyspace('CassandraExample');
+
+// start using the created keyspace
+$cassandra->useKeyspace('CassandraExample');
+
+// if a request fails, it will be retried for this many times, each time backing
+// down for a bit longer period to prevent floods; defaults to 5
+$cassandra->setMaxCallRetries(5);
+
+// create a standard column family with given column metadata
+$cassandra->createStandardColumnFamily(
+ 'CassandraExample', // keyspace name
+ 'user', // the column-family name
+ array( // list of columns with metadata
+ array(
+ 'name' => 'name',
+ 'type' => Cassandra::TYPE_UTF8,
+ 'index-type' => Cassandra::INDEX_KEYS, // create secondary index
+ 'index-name' => 'NameIdx'
+ ),
+ array(
+ 'name' => 'email',
+ 'type' => Cassandra::TYPE_UTF8
+ ),
+ array(
+ 'name' => 'age',
+ 'type' => Cassandra::TYPE_INTEGER,
+ 'index-type' => Cassandra::INDEX_KEYS,
+ 'index-name' => 'AgeIdx'
+ )
+ )
+ // actually accepts more parameters with reasonable defaults
+);
+
+// create a super column family
+$cassandra->createSuperColumnFamily(
+ 'CassandraExample',
+ 'cities',
+ array(
+ array(
+ 'name' => 'population',
+ 'type' => Cassandra::TYPE_INTEGER
+ ),
+ array(
+ 'name' => 'comment',
+ 'type' => Cassandra::TYPE_UTF8
+ )
+ ),
+ // see the definition for these additional optional parameters
+ Cassandra::TYPE_UTF8,
+ Cassandra::TYPE_UTF8,
+ Cassandra::TYPE_UTF8,
+ 'Capitals supercolumn test',
+ 1000,
+ 1000,
+ 0.5
+);
+
+// lets fetch and display the schema of created keyspace
+$schema = $cassandra->getKeyspaceSchema('CassandraExample');
+echo 'Schema: <pre>'.print_r($schema, true).'</pre><hr/>';
+
+// should we need to, we can access the low-level client directly
+$version = $cassandra->getConnection()->getClient()->describe_version();
+echo 'Version directly: <pre>'.print_r($version, true).'</pre><hr/>';
+
+// if implemented, use the wrapped methods as these are smarter - can retry etc
+$version = $cassandra->getVersion();
+echo 'Version through wrapper: <pre>'.print_r($version, true).'</pre><hr/>';
+
+// cluster is a pool of connections
+$cluster = $cassandra->getCluster();
+echo 'Cluster: <pre>'.print_r($cluster, true).'</pre><hr/>';
+
+// you can ask the cluster for a connection to a random seed server from pool
+$connection = $cluster->getConnection();
+echo 'Connection: <pre>'.print_r($connection, true).'</pre><hr/>';
+
+// access column family, using the singleton syntax
+// there is shorter "cf" methid that is an alias to "columnFamily"
+$userColumnFamily = Cassandra::getInstance()->columnFamily('user');
+echo 'Column family "user": <pre>'.print_r($userColumnFamily, true).'</pre><hr/>';
+
+// lets insert some test data using the convinience method "set" of Cassandra
+// the syntax is COLUMN_FAMILY_NAME.KEY_NAME
+$cassandra->set(
+ 'user.john',
+ array(
+ 'email' => 'john@smith.com',
+ 'name' => 'John Smith',
+ 'age' => 34
+ )
+);
+
+// when inserting data, it's ok if key name contains ".", no need to escape them
+$cassandra->set(
+ 'user.jane.doe',
+ array(
+ 'email' => 'jane@doe.com',
+ 'name' => 'Jane Doe',
+ 'age' => 24
+ )
+);
+
+// longer way of inserting data, first getting the column family
+$cassandra->cf('user')->set(
+ 'chuck', // key name
+ array( // column names and values
+ 'email' => 'chuck@norris.com',
+ 'name' => 'Chuck Norris',
+ 'age' => 24
+ ),
+ Cassandra::CONSISTENCY_QUORUM // optional consistency to use
+ // also accepts optional custom timestamp and time to live
+);
+
+// lets fetch all the information about user john
+$john = $cassandra->get('user.john');
+echo 'User "john": <pre>'.print_r($john, true).'</pre><hr/>';
+
+// since the jane key "jane.doe" includes a ".", we have to escape it
+$jane = $cassandra->get('user.'.Cassandra::escape('jane.doe'));
+echo 'User "jane.doe": <pre>'.print_r($jane, true).'</pre><hr/>';
+
+// there is some syntatic sugar on the query of Cassandra::get() allowing you
+// to fetch specific columns, ranges of them, limit amount etc. for example,
+// lets only fetch columns name and age
+$chuck = $cassandra->get('user.chuck:name,age');
+echo 'User "chuck", name and age: <pre>'.print_r($chuck, true).'</pre><hr/>';
+
+// fetch all solumns from age to name (gets all columns in-between too)
+$chuck2 = $cassandra->get('user.chuck:age-name');
+echo 'User "chuck", columns ago to name: <pre>'.print_r($chuck2, true).'</pre><hr/>';
+
+// the range columns do not need to exist, we can get character ranges
+$chuck3 = $cassandra->get('user.chuck:a-z');
+echo 'User "chuck", columns a-z: <pre>'.print_r($chuck3, true).'</pre><hr/>';
+
+// when performing range queries, we can also limit the number of columns
+// returned (2); also the method accepts consistency level as second parameter
+$chuck4 = $cassandra->get('user.chuck:a-z|2', Cassandra::CONSISTENCY_ALL);
+echo 'User "chuck", columns a-z, limited to 2 columns: <pre>'.print_r($chuck4, true).'</pre><hr/>';
+
+// the Cassandra::get() is a convinience method proxying to lower level
+// CassandraColumnFamily::get(), no need to worry about escaping with this.
+// column family has additional methods getAll(), getColumns(), getColumnRange()
+// that all map to lower level get() calls with more appopriate parameters
+$jane2 = $cassandra->cf('user')->get('jane.doe');
+echo 'User "jane.doe", lower level api: <pre>'.print_r($jane2, true).'</pre><hr/>';
+
+// we defined a secondary index on "age" column of "user" column family so we
+// can use CassandraColumnFamily::getWhere() to fetch users of specific age.
+// this returns an iterator that you can go over with foreach or use the
+// getAll() method that fetches all the data and returns an array
+$aged24 = $cassandra->cf('user')->getWhere(array('age' => 24));
+echo 'Users at age 24: <pre>'.print_r($aged24->getAll(), true).'</pre><hr/>';
+
+// if we know we are going to need to values of several keys, we can request
+// them in a single query for better performance
+$chuckAndJohn = $cassandra->cf('user')->getMultiple(array('chuck', 'john'));
+echo 'Users "chuck" and "john": <pre>'.print_r($chuckAndJohn, true).'</pre><hr/>';
+
+// we can fetch a range of keys but this is predictable only if using an
+// order preserving partitioner, Cassandra defaults to random one
+// again as there may be more results than it's reasonable to fetch in a single
+// query, an iterator is returned that can make several smaller range queries
+// as the data is iterated
+$usersAZ = $cassandra->cf('user')->getRange('a', 'z');
+echo 'Users with keys in range a-z: <pre>'.print_r($usersAZ->getAll(), true).'</pre><hr/>';
+
+// find the number of columns a key has, we could also request for ranges
+$chuckColumnCount = $cassandra->cf('user')->getColumnCount('chuck');
+echo 'User "chuck" column count: <pre>'.print_r($chuckColumnCount, true).'</pre><hr/>';
+
+// we can find column counts for several keys at once
+$chuckJaneColumnCounts = $cassandra->cf('user')->getColumnCounts(array('chuck', 'jane.doe'));
+echo 'User "chuck" and "jane.doe" column counts: <pre>'.print_r($chuckJaneColumnCounts, true).'</pre><hr/>';
+
+// setting supercolumn values is similar to normal column families
+$cassandra->set(
+ 'cities.Estonia',
+ array(
+ 'Tallinn' => array(
+ 'population' => '411980',
+ 'comment' => 'Capital of Estonia',
+ 'size' => 'big'
+ ),
+ 'Tartu' => array(
+ 'population' => '98589',
+ 'comment' => 'City of good thoughts',
+ 'size' => 'medium'
+ )
+ )
+);
+
+// fetch all columns of Tartu in Estonia of cities
+$tartu = $cassandra->cf('cities')->getAll('Estonia', 'Tartu');
+echo 'Super-column cities.Estonia.Tartu: <pre>'.print_r($tartu, true).'</pre><hr/>';
+
+// we could also use the higher level Cassandra::get() to fetch supercolumn info
+// we can still use the additional filters of columns
+$tallinn = $cassandra->get('cities.Estonia.Tallinn:population,size');
+echo 'Super-column cities.Estonia.Tallinn: <pre>'.print_r($tallinn, true).'</pre><hr/>';
+
+// you can delete all the data in a column family using "truncate"
+$cassandra->truncate('user');
+
+// you may choose to drop an entire keyspace
+$cassandra->dropKeyspace('CassandraExample');
+
+?>
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