<?php
namespace Illuminate\Cache;
use Aws\DynamoDb\DynamoDbClient;
use Aws\DynamoDb\Exception\DynamoDbException;
use Illuminate\Contracts\Cache\LockProvider;
use Illuminate\Contracts\Cache\Store;
use Illuminate\Support\Carbon;
use Illuminate\Support\InteractsWithTime;
use Illuminate\Support\Str;
use RuntimeException;
class DynamoDbStore implements LockProvider, Store
{
use InteractsWithTime;
/**
* The DynamoDB client instance.
*
* @var \Aws\DynamoDb\DynamoDbClient
*/
protected $dynamo;
/**
* The table name.
*
* @var string
*/
protected $table;
/**
* The name of the attribute that should hold the key.
*
* @var string
*/
protected $keyAttribute;
/**
* The name of the attribute that should hold the value.
*
* @var string
*/
protected $valueAttribute;
/**
* The name of the attribute that should hold the expiration timestamp.
*
* @var string
*/
protected $expirationAttribute;
/**
* A string that should be prepended to keys.
*
* @var string
*/
protected $prefix;
/**
* Create a new store instance.
*
* @param \Aws\DynamoDb\DynamoDbClient $dynamo
* @param string $table
* @param string $keyAttribute
* @param string $valueAttribute
* @param string $expirationAttribute
* @param string $prefix
* @return void
*/
public function __construct(DynamoDbClient $dynamo,
$table,
$keyAttribute = 'key',
$valueAttribute = 'value',
$expirationAttribute = 'expires_at',
$prefix = '')
{
$this->table = $table;
$this->dynamo = $dynamo;
$this->keyAttribute = $keyAttribute;
$this->valueAttribute = $valueAttribute;
$this->expirationAttribute = $expirationAttribute;
$this->setPrefix($prefix);
}
/**
* Retrieve an item from the cache by key.
*
* @param string $key
* @return mixed
*/
public function get($key)
{
$response = $this->dynamo->getItem([
'TableName' => $this->table,
'ConsistentRead' => false,
'Key' => [
$this->keyAttribute => [
'S' => $this->prefix.$key,
],
],
]);
if (! isset($response['Item'])) {
return;
}
if ($this->isExpired($response['Item'])) {
return;
}
if (isset($response['Item'][$this->valueAttribute])) {
return $this->unserialize(
$response['Item'][$this->valueAttribute]['S'] ??
$response['Item'][$this->valueAttribute]['N'] ??
null
);
}
}
/**
* Retrieve multiple items from the cache by key.
*
* Items not found in the cache will have a null value.
*
* @param array $keys
* @return array
*/
public function many(array $keys)
{
$prefixedKeys = array_map(function ($key) {
return $this->prefix.$key;
}, $keys);
$response = $this->dynamo->batchGetItem([
'RequestItems' => [
$this->table => [
'ConsistentRead' => false,
'Keys' => collect($prefixedKeys)->map(function ($key) {
return [
$this->keyAttribute => [
'S' => $key,
],
];
})->all(),
],
],
]);
$now = Carbon::now();
return array_merge(collect(array_flip($keys))->map(function () {
//
})->all(), collect($response['Responses'][$this->table])->mapWithKeys(function ($response) use ($now) {
if ($this->isExpired($response, $now)) {
$value = null;
} else {
$value = $this->unserialize(
$response[$this->valueAttribute]['S'] ??
$response[$this->valueAttribute]['N'] ??
null
);
}
return [Str::replaceFirst($this->prefix, '', $response[$this->keyAttribute]['S']) => $value];
})->all());
}
/**
* Determine if the given item is expired.
*
* @param array $item
* @param \DateTimeInterface|null $expiration
* @return bool
*/
protected function isExpired(array $item, $expiration = null)
{
$expiration = $expiration ?: Carbon::now();
return isset($item[$this->expirationAttribute]) &&
$expiration->getTimestamp() >= $item[$this->expirationAttribute]['N'];
}
/**
* Store an item in the cache for a given number of seconds.
*
* @param string $key
* @param mixed $value
* @param int $seconds
* @return bool
*/
public function put($key, $value, $seconds)
{
$this->dynamo->putItem([
'TableName' => $this->table,
'Item' => [
$this->keyAttribute => [
'S' => $this->prefix.$key,
],
$this->valueAttribute => [
$this->type($value) => $this->serialize($value),
],
$this->expirationAttribute => [
'N' => (string) $this->toTimestamp($seconds),
],
],
]);
return true;
}
/**
* Store multiple items in the cache for a given number of $seconds.
*
* @param array $values
* @param int $seconds
* @return bool
*/
public function putMany(array $values, $seconds)
{
$expiration = $this->toTimestamp($seconds);
$this->dynamo->batchWriteItem([
'RequestItems' => [
$this->table => collect($values)->map(function ($value, $key) use ($expiration) {
return [
'PutRequest' => [
'Item' => [
$this->keyAttribute => [
'S' => $this->prefix.$key,
],
$this->valueAttribute => [
$this->type($value) => $this->serialize($value),
],
$this->expirationAttribute => [
'N' => (string) $expiration,
],
],
],
];
})->values()->all(),
],
]);
return true;
}
/**
* Store an item in the cache if the key doesn't exist.
*
* @param string $key
* @param mixed $value
* @param int $seconds
* @return bool
*/
public function add($key, $value, $seconds)
{
try {
$this->dynamo->putItem([
'TableName' => $this->table,
'Item' => [
$this->keyAttribute => [
'S' => $this->prefix.$key,
],
$this->valueAttribute => [
$this->type($value) => $this->serialize($value),
],
$this->expirationAttribute => [
'N' => (string) $this->toTimestamp($seconds),
],
],
'ConditionExpression' => 'attribute_not_exists(#key) OR #expires_at < :now',
'ExpressionAttributeNames' => [
'#key' => $this->keyAttribute,
'#expires_at' => $this->expirationAttribute,
],
'ExpressionAttributeValues' => [
':now' => [
'N' => (string) Carbon::now()->getTimestamp(),
],
],
]);
return true;
} catch (DynamoDbException $e) {
if (Str::contains($e->getMessage(), 'ConditionalCheckFailed')) {
return false;
}
throw $e;
}
}
/**
* Increment the value of an item in the cache.
*
* @param string $key
* @param mixed $value
* @return int|bool
*/
public function increment($key, $value = 1)
{
try {
$response = $this->dynamo->updateItem([
'TableName' => $this->table,
'Key' => [
$this->keyAttribute => [
'S' => $this->prefix.$key,
],
],
'ConditionExpression' => 'attribute_exists(#key) AND #expires_at > :now',
'UpdateExpression' => 'SET #value = #value + :amount',
'ExpressionAttributeNames' => [
'#key' => $this->keyAttribute,
'#value' => $this->valueAttribute,
'#expires_at' => $this->expirationAttribute,
],
'ExpressionAttributeValues' => [
':now' => [
'N' => (string) Carbon::now()->getTimestamp(),
],
':amount' => [
'N' => (string) $value,
],
],
'ReturnValues' => 'UPDATED_NEW',
]);
return (int) $response['Attributes'][$this->valueAttribute]['N'];
} catch (DynamoDbException $e) {
if (Str::contains($e->getMessage(), 'ConditionalCheckFailed')) {
return false;
}
throw $e;
}
}
/**
* Decrement the value of an item in the cache.
*
* @param string $key
* @param mixed $value
* @return int|bool
*/
public function decrement($key, $value = 1)
{
try {
$response = $this->dynamo->updateItem([
'TableName' => $this->table,
'Key' => [
$this->keyAttribute => [
'S' => $this->prefix.$key,
],
],
'ConditionExpression' => 'attribute_exists(#key) AND #expires_at > :now',
'UpdateExpression' => 'SET #value = #value - :amount',
'ExpressionAttributeNames' => [
'#key' => $this->keyAttribute,
'#value' => $this->valueAttribute,
'#expires_at' => $this->expirationAttribute,
],
'ExpressionAttributeValues' => [
':now' => [
'N' => (string) Carbon::now()->getTimestamp(),
],
':amount' => [
'N' => (string) $value,
],
],
'ReturnValues' => 'UPDATED_NEW',
]);
return (int) $response['Attributes'][$this->valueAttribute]['N'];
} catch (DynamoDbException $e) {
if (Str::contains($e->getMessage(), 'ConditionalCheckFailed')) {
return false;
}
throw $e;
}
}
/**
* Store an item in the cache indefinitely.
*
* @param string $key
* @param mixed $value
* @return bool
*/
public function forever($key, $value)
{
return $this->put($key, $value, now()->addYears(5)->getTimestamp());
}
/**
* Get a lock instance.
*
* @param string $name
* @param int $seconds
* @param string|null $owner
* @return \Illuminate\Contracts\Cache\Lock
*/
public function lock($name, $seconds = 0, $owner = null)
{
return new DynamoDbLock($this, $this->prefix.$name, $seconds, $owner);
}
/**
* Restore a lock instance using the owner identifier.
*
* @param string $name
* @param string $owner
* @return \Illuminate\Contracts\Cache\Lock
*/
public function restoreLock($name, $owner)
{
return $this->lock($name, 0, $owner);
}
/**
* Remove an item from the cache.
*
* @param string $key
* @return bool
*/
public function forget($key)
{
$this->dynamo->deleteItem([
'TableName' => $this->table,
'Key' => [
$this->keyAttribute => [
'S' => $this->prefix.$key,
],
],
]);
return true;
}
/**
* Remove all items from the cache.
*
* @return bool
*/
public function flush()
{
throw new RuntimeException('DynamoDb does not support flushing an entire table. Please create a new table.');
}
/**
* Get the UNIX timestamp for the given number of seconds.
*
* @param int $seconds
* @return int
*/
protected function toTimestamp($seconds)
{
return $seconds > 0
? $this->availableAt($seconds)
: Carbon::now()->getTimestamp();
}
/**
* Serialize the value.
*
* @param mixed $value
* @return mixed
*/
protected function serialize($value)
{
return is_numeric($value) ? (string) $value : serialize($value);
}
/**
* Unserialize the value.
*
* @param mixed $value
* @return mixed
*/
protected function unserialize($value)
{
if (filter_var($value, FILTER_VALIDATE_INT) !== false) {
return (int) $value;
}
if (is_numeric($value)) {
return (float) $value;
}
return unserialize($value);
}
/**
* Get the DynamoDB type for the given value.
*
* @param mixed $value
* @return string
*/
protected function type($value)
{
return is_numeric($value) ? 'N' : 'S';
}
/**
* Get the cache key prefix.
*
* @return string
*/
public function getPrefix()
{
return $this->prefix;
}
/**
* Set the cache key prefix.
*
* @param string $prefix
* @return void
*/
public function setPrefix($prefix)
{
$this->prefix = ! empty($prefix) ? $prefix.':' : '';
}
}