Execution: refactored promise adapters

This commit is contained in:
vladar 2016-12-03 02:06:28 +07:00
parent 3a375bb78e
commit 48d78412ec
4 changed files with 148 additions and 125 deletions

View File

@ -107,8 +107,12 @@ class Executor
}
$exeContext = self::buildExecutionContext($schema, $ast, $rootValue, $contextValue, $variableValues, $operationName);
$executor = new self($exeContext, self::getPromiseAdapter());
return $executor->executeQuery();
$promiseAdapter = self::getPromiseAdapter();
$executor = new self($exeContext, $promiseAdapter);
$result = $executor->executeQuery();
return $result;
}
/**
@ -205,37 +209,32 @@ class Executor
$this->promises = $promiseAdapter;
}
/**
* @return Promise
*/
private function executeQuery()
{
try {
// Return a Promise that will eventually resolve to the data described by
// The "Response" section of the GraphQL specification.
//
// If errors are encountered while executing a GraphQL field, only that
// field and its descendants will be omitted, and sibling fields will still
// be executed. An execution which encounters errors will still result in a
// resolved Promise.
$result = $this->promises->createPromise(function (callable $resolve) {
return $resolve($this->executeOperation($this->exeContext->operation, $this->exeContext->rootValue));
});
$result = $this->promises->then($result, null, function ($error) {
// Return a Promise that will eventually resolve to the data described by
// The "Response" section of the GraphQL specification.
//
// If errors are encountered while executing a GraphQL field, only that
// field and its descendants will be omitted, and sibling fields will still
// be executed. An execution which encounters errors will still result in a
// resolved Promise.
$result = $this->promises->createPromise(function (callable $resolve) {
return $resolve($this->executeOperation($this->exeContext->operation, $this->exeContext->rootValue));
});
return $result
->then(null, function ($error) {
// Errors from sub-fields of a NonNull type may propagate to the top level,
// at which point we still log the error and null the parent field, which
// in this case is the entire response.
$this->exeContext->addError($error);
return null;
});
$result = $this->promises->then($result, function ($data) {
})
->then(function ($data) {
return new ExecutionResult((array) $data, $this->exeContext->errors);
});
return $result;
} catch (Error $e) {
$this->exeContext->addError($e);
$data = null;
}
return new ExecutionResult((array) $data, $this->exeContext->errors);
}
/**
@ -310,7 +309,7 @@ class Executor
*/
private function executeFieldsSerially(ObjectType $parentType, $sourceValue, $path, $fields)
{
$results = $this->promises->createResolvedPromise([]);
$prevPromise = $this->promises->createResolvedPromise([]);
$process = function ($results, $responseName, $path, $parentType, $sourceValue, $fieldNodes) {
$fieldPath = $path;
@ -319,8 +318,8 @@ class Executor
if ($result === self::$UNDEFINED) {
return $results;
}
if ($this->promises->isPromise($result)) {
return $this->promises->then($result, function ($resolvedResult) use ($responseName, $results) {
if ($result instanceof Promise) {
return $result->then(function ($resolvedResult) use ($responseName, $results) {
$results[$responseName] = $resolvedResult;
return $results;
});
@ -330,22 +329,14 @@ class Executor
};
foreach ($fields as $responseName => $fieldNodes) {
if ($this->promises->isPromise($results)) {
$results = $this->promises->then($results, function ($resolvedResults) use ($process, $responseName, $path, $parentType, $sourceValue, $fieldNodes) {
return $process($resolvedResults, $responseName, $path, $parentType, $sourceValue, $fieldNodes);
});
} else {
$results = $process($results, $responseName, $path, $parentType, $sourceValue, $fieldNodes);
}
}
if ($this->promises->isPromise($results)) {
return $this->promises->then($results, function ($resolvedResults) {
return self::fixResultsIfEmptyArray($resolvedResults);
$prevPromise = $prevPromise->then(function ($resolvedResults) use ($process, $responseName, $path, $parentType, $sourceValue, $fieldNodes) {
return $process($resolvedResults, $responseName, $path, $parentType, $sourceValue, $fieldNodes);
});
}
return self::fixResultsIfEmptyArray($results);
return $prevPromise->then(function ($resolvedResults) {
return self::fixResultsIfEmptyArray($resolvedResults);
});
}
/**
@ -370,7 +361,7 @@ class Executor
if ($result === self::$UNDEFINED) {
continue;
}
if (!$containsPromise && $this->promises->isPromise($result)) {
if (!$containsPromise && $result instanceof Promise) {
$containsPromise = true;
}
$finalResults[$responseName] = $result;
@ -405,7 +396,7 @@ class Executor
$promise = $this->promises->createPromiseAll($valuesAndPromises);
return $this->promises->then($promise, function($values) use ($keys) {
return $promise->then(function($values) use ($keys) {
$resolvedResults = [];
foreach ($values as $i => $value) {
$resolvedResults[$keys[$i]] = $value;
@ -669,7 +660,7 @@ class Executor
* @param mixed $source
* @param mixed $context
* @param ResolveInfo $info
* @return \Exception|mixed
* @return \Exception|Promise|mixed
*/
private function resolveOrError($fieldDef, $fieldNode, $resolveFn, $source, $context, $info)
{
@ -682,7 +673,15 @@ class Executor
$this->exeContext->variableValues
);
return call_user_func($resolveFn, $source, $args, $context, $info);
$value = call_user_func($resolveFn, $source, $args, $context, $info);
// Adopt promises from external system:
if ($this->promises->isThenable($value)) {
$value = $this->promises->convert($value);
Utils::invariant($value instanceof Promise);
}
return $value;
} catch (\Exception $error) {
return $error;
}
@ -731,8 +730,8 @@ class Executor
$path,
$result
);
if ($this->promises->isPromise($completed)) {
return $this->promises->then($completed, null, function ($error) use ($exeContext) {
if ($completed instanceof Promise) {
return $completed->then(null, function ($error) use ($exeContext) {
$exeContext->addError($error);
return $this->promises->createResolvedPromise(null);
});
@ -775,8 +774,8 @@ class Executor
$path,
$result
);
if ($this->promises->isPromise($completed)) {
return $this->promises->then($completed, null, function ($error) use ($fieldNodes, $path) {
if ($completed instanceof Promise) {
return $completed->then(null, function ($error) use ($fieldNodes, $path) {
return $this->promises->createRejectedPromise(Error::createLocatedError($error, $fieldNodes, $path));
});
}
@ -825,8 +824,8 @@ class Executor
)
{
// If result is a Promise, apply-lift over completeValue.
if ($this->promises->isPromise($result)) {
return $this->promises->then($result, function (&$resolved) use ($returnType, $fieldNodes, $info, $path) {
if ($result instanceof Promise) {
return $result->then(function (&$resolved) use ($returnType, $fieldNodes, $info, $path) {
return $this->completeValue($returnType, $fieldNodes, $info, $path, $resolved);
});
}
@ -1018,7 +1017,7 @@ class Executor
$fieldPath = $path;
$fieldPath[] = $i++;
$completedItem = $this->completeValueCatchingError($itemType, $fieldNodes, $info, $fieldPath, $item);
if (!$containsPromise && $this->promises->isPromise($completedItem)) {
if (!$containsPromise && $completedItem instanceof Promise) {
$containsPromise = true;
}
$completedItems[] = $completedItem;

View File

@ -1,81 +1,77 @@
<?php
namespace GraphQL\Executor\Promise\Adapter;
use GraphQL\Executor\Promise\PromiseAdapter;;
use React\Promise\FulfilledPromise;
use React\Promise\Promise;
use React\Promise\PromiseInterface;
use GraphQL\Executor\Promise\Promise;
use GraphQL\Executor\Promise\PromiseAdapter;
use GraphQL\Utils;
use React\Promise\Promise as ReactPromise;
use React\Promise\PromiseInterface as ReactPromiseInterface;
class ReactPromiseAdapter implements PromiseAdapter
{
/**
* Return true if value is promise
*
* @param mixed $value
*
* @return bool
* @inheritdoc
*/
public function isPromise($value)
public function isThenable($value)
{
return $value instanceof PromiseInterface;
}
/**
* Accepts value qualified by `isPromise` and returns other promise.
*
* @param Promise $promise
* @param callable|null $onFullFilled
* @param callable|null $onRejected
* @return mixed
*/
public function then($promise, callable $onFullFilled = null, callable $onRejected = null)
{
return $promise->then($onFullFilled, $onRejected);
return $value instanceof ReactPromiseInterface;
}
/**
* @inheritdoc
*/
public function convert($promise)
{
return new Promise($promise, $this);
}
/**
* @inheritdoc
*/
public function then(Promise $promise, callable $onFulfilled = null, callable $onRejected = null)
{
/** @var $adoptedPromise ReactPromiseInterface */
$adoptedPromise = $promise->adoptedPromise;
return new Promise($adoptedPromise->then($onFulfilled, $onRejected), $this);
}
/**
* @inheritdoc
*
* @return PromiseInterface
*/
public function createPromise(callable $resolver)
{
$promise = new Promise($resolver);
return $promise;
$promise = new ReactPromise($resolver);
return new Promise($promise, $this);
}
/**
* @inheritdoc
*
* @return FulfilledPromise
*/
public function createResolvedPromise($promiseOrValue = null)
public function createResolvedPromise($value = null)
{
return \React\Promise\resolve($promiseOrValue);
$promise = \React\Promise\resolve($value);
return new Promise($promise, $this);
}
/**
* @inheritdoc
*
* @return \React\Promise\RejectedPromise
*/
public function createRejectedPromise($reason)
public function createRejectedPromise(\Exception $reason)
{
return \React\Promise\reject($reason);
$promise = \React\Promise\reject($reason);
return new Promise($promise, $this);
}
/**
* Given an array of promises, return a promise that is fulfilled when all the
* items in the array are fulfilled.
*
* @param mixed $promisesOrValues Promises or values.
*
* @return mixed a Promise
* @inheritdoc
*/
public function createPromiseAll($promisesOrValues)
public function createPromiseAll(array $promisesOrValues)
{
return \React\Promise\all($promisesOrValues);
// TODO: rework with generators when PHP minimum required version is changed to 5.5+
$promisesOrValues = Utils::map($promisesOrValues, function ($item) {
return $item instanceof Promise ? $item->adoptedPromise : $item;
});
$promise = \React\Promise\all($promisesOrValues);
return new Promise($promise, $this);
}
}

View File

@ -1,18 +1,39 @@
<?php
namespace GraphQL\Executor\Promise;
use GraphQL\Utils;
/**
* A simple Promise representation
* this interface helps to document the code
* Convenience wrapper for promises represented by Promise Adapter
*/
interface Promise
class Promise
{
private $adapter;
public $adoptedPromise;
/**
* @param callable|null $onFullFilled
* Promise constructor.
*
* @param mixed $adoptedPromise
* @param PromiseAdapter $adapter
*/
public function __construct($adoptedPromise, PromiseAdapter $adapter)
{
Utils::invariant(!$adoptedPromise instanceof self, 'Expecting promise from adapted system, got ' . __CLASS__);
$this->adapter = $adapter;
$this->adoptedPromise = $adoptedPromise;
}
/**
* @param callable|null $onFulfilled
* @param callable|null $onRejected
*
* @return Promise
*/
public function then(callable $onFullFilled = null, callable $onRejected = null);
public function then(callable $onFulfilled = null, callable $onRejected = null)
{
return $this->adapter->then($this, $onFulfilled, $onRejected);
}
}

View File

@ -1,46 +1,53 @@
<?php
namespace GraphQL\Executor\Promise;
interface PromiseAdapter
{
/**
* Return true if value is promise
* Return true if value is promise of underlying system
*
* @param mixed $value
*
* @return bool
*/
public function isPromise($value);
public function isThenable($value);
/**
* Accepts value qualified by `isPromise` and returns other promise.
* Underlying mechanics of this process must match Promises/A+ specs
* Converts promise of underlying system into Promise instance
*
* @param $promise
* @param callable|null $onFullFilled
* @param callable|null $onRejected
* @return mixed
* @param $adaptedPromise
* @return Promise
*/
public function then($promise, callable $onFullFilled = null, callable $onRejected = null);
public function convert($adaptedPromise);
/**
* Accepts our Promise wrapper, extracts adopted promise out of it and executes actual `then` logic described
* in Promises/A+ specs. Then returns new wrapped Promise instance.
*
* @param Promise $promise
* @param callable|null $onFulfilled
* @param callable|null $onRejected
*
* @return Promise
*/
public function then(Promise $promise, callable $onFulfilled = null, callable $onRejected = null);
/**
* Creates a Promise
*
* @param callable $resolver
*
* @return Promise
*/
public function createPromise(callable $resolver);
/**
* Creates a full filed Promise for a value if the value is not a promise.
* Creates a fulfilled Promise for a value if the value is not a promise.
*
* @param mixed $promiseOrValue
* @param mixed $value
*
* @return Promise a full filed Promise
* @return Promise
*/
public function createResolvedPromise($promiseOrValue = null);
public function createResolvedPromise($value = null);
/**
* Creates a rejected promise for a reason if the reason is not a promise. If
@ -48,17 +55,17 @@ interface PromiseAdapter
*
* @param mixed $reason
*
* @return Promise a rejected promise
* @return Promise
*/
public function createRejectedPromise($reason);
public function createRejectedPromise(\Exception $reason);
/**
* Given an array of promises, return a promise that is fulfilled when all the
* Given an array of promises (or values), returns a promise that is fulfilled when all the
* items in the array are fulfilled.
*
* @param mixed $promisesOrValues Promises or values.
* @param array $promisesOrValues Promises or values.
*
* @return Promise equivalent to Promise.all result
* @return Promise
*/
public function createPromiseAll($promisesOrValues);
public function createPromiseAll(array $promisesOrValues);
}