NodalFlow::interruptFlow() - Code Metrics - Inspection of "unified flow map" - fab2s/NodalFlow - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#1)

by Fabrice

created 2017-11-22 10:09 UTC

NodalFlow::interruptFlow() B

↳ Parent: Project

Complexity

Conditions	4
Paths	5

Size

Total Lines	22
Code Lines	16

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	22
c	0
b	0
f	0
rs	8.9197
cc	4
eloc	16
nc	5
nop	2

<?php

/*
 * This file is part of NodalFlow.
 *     (c) Fabrice de Stefanis / https://github.com/fab2s/NodalFlow
 * This source file is licensed under the MIT license which you will
 * find in the LICENSE file or at https://opensource.org/licenses/MIT
 */

namespace fab2s\NodalFlow;

use fab2s\NodalFlow\Callbacks\CallbackInterface;
use fab2s\NodalFlow\Flows\FlowAbstract;
use fab2s\NodalFlow\Flows\FlowMap;
use fab2s\NodalFlow\Flows\FlowStatus;
use fab2s\NodalFlow\Flows\InterrupterInterface;
use fab2s\NodalFlow\Nodes\BranchNodeInterface;
use fab2s\NodalFlow\Nodes\ExecNodeInterface;
use fab2s\NodalFlow\Nodes\NodeInterface;
use fab2s\NodalFlow\Nodes\TraversableNodeInterface;

/**
 * Class NodalFlow
 */
class NodalFlow extends FlowAbstract
{
    /**
     * Flow steps triggering callbacks
     */
    const FLOW_START    = 'start';
    const FLOW_PROGRESS = 'progress';
    const FLOW_SUCCESS  = 'success';
    const FLOW_FAIL     = 'fail';

    /**
     * @var array
     */
    protected $flowIncrements = [];

    /**
     * The current Node index
     *
     * @var int
     */
    protected $nodeIdx = 0;

    /**
     * The last index value
     *
     * @var int
     */
    protected $lastIdx = 0;

    /**
     * The number of Node in this Flow
     *
     * @var int
     */
    protected $nodeCount = 0;

    /**
     * The number of iteration within this Flow
     *
     * @var int
     */
    protected $numIterate = 0;

    /**
     * The current registered Callback class if any
     *
     * @var CallbackInterface|null
     */
    protected $callBack;

    /**
     * Instantiate a Flow
     */
    public function __construct()
    {
        $this->flowMap = new FlowMap($this, $this->flowIncrements);
    }

    /**
     * Adds a Node to the flow
     *
     * @param NodeInterface $node
     *
     * @throws NodalFlowException
     *
     * @return $this
     */
    public function add(NodeInterface $node)
    {
        if ($node instanceof BranchNodeInterface) {
            // this node is a branch, set it's parent
            $node->getPayload()->setParent($this);
        }

        $node->setCarrier($this);

        $this->flowMap->register($node, $this->nodeIdx);
        $this->nodes[$this->nodeIdx] = $node;

        ++$this->nodeIdx;

        return $this;
    }

    /**
     * Adds a Payload Node to the Flow
     *
     * @param callable $payload
     * @param mixed    $isAReturningVal
     * @param mixed    $isATraversable
     *
     * @return $this
     */
    public function addPayload(callable $payload, $isAReturningVal, $isATraversable = false)
    {
        $node = PayloadNodeFactory::create($payload, $isAReturningVal, $isATraversable);

        $this->add($node);

        return $this;
    }

    /**
     * Register callback class
     *
     * @param CallbackInterface $callBack
     *
     * @return $this
     */
    public function setCallBack(CallbackInterface $callBack)
    {
        $this->callBack = $callBack;

        return $this;
    }

    /**
     * Execute the flow
     *
     * @param null|mixed $param The eventual init argument to the first node
     *                          or, in case of a branch, the last relevant
     *                          argument from upstream Flow
     *
     * @throws NodalFlowException
     *
     * @return mixed the last result of the
     *               last returning value node
     */
    public function exec($param = null)
    {
        try {
            $result = $this->rewind()
                    ->flowStart()
                    ->recurse($param);

            // set flowStatus to make sure that we have the proper
            // value in flowEnd even when overridden without (or when
            // improperly) calling parent
            if ($this->flowStatus->isRunning()) {
                $this->flowStatus = new FlowStatus(FlowStatus::FLOW_CLEAN);
            }

            $this->flowEnd();

            return $result;
        } catch (\Exception $e) {
            $this->flowStatus = new FlowStatus(FlowStatus::FLOW_EXCEPTION);
            $this->flowEnd();
            if ($e instanceof NodalFlowException) {
                throw $e;
            }

            throw new NodalFlowException('Flow execution failed', 0, $e, [
                'nodeMap' => $this->getNodeMap(),
            ]);
        }
    }

    /**
     * Rewinds the Flow
     *
     * @return $this
     */
    public function rewind()
    {
        $this->nodeCount       = count($this->nodes);
        $this->lastIdx         = $this->nodeCount - 1;
        $this->break           = false;
        $this->continue        = false;
        $this->interruptNodeId = null;

        return $this;
    }

    /**
     * Break the flow's execution, conceptually similar to breaking
     * a regular loop
     *
     * @param InterrupterInterface|null $flowInterrupt
     *
     * @return $this
     */
    public function breakFlow(InterrupterInterface $flowInterrupt = null)
    {
        return $this->interruptFlow(InterrupterInterface::TYPE_BREAK, $flowInterrupt);
    }

    /**
     * Continue the flow's execution, conceptually similar to continuing
     * a regular loop
     *
     * @param InterrupterInterface|null $flowInterrupt
     *
     * @return $this
     */
    public function continueFlow(InterrupterInterface $flowInterrupt = null)
    {
        return $this->interruptFlow(InterrupterInterface::TYPE_CONTINUE, $flowInterrupt);
    }

    /**
     * Triggered just before the flow starts
     *
     * @return $this
     */
    protected function flowStart()
    {
        $this->flowMap->incrementFlow('num_exec')->flowStart();
        $this->triggerCallback(static::FLOW_START);

        // flow is started
        $this->flowStatus = new FlowStatus(FlowStatus::FLOW_RUNNING);

        return $this;
    }

    /**
     * Triggered right after the flow stops
     *
     * @return $this
     */
    protected function flowEnd()
    {
        $this->flowMap->flowEnd();

        $this->triggerCallback($this->flowStatus->isException() ? static::FLOW_FAIL : static::FLOW_SUCCESS);

        return $this;
    }

    /**
     * Recurse over nodes which may as well be Flows and
     * Traversable ...
     * Welcome to the abysses of recursion or iter-recursion ^^
     *
     * `recurse` perform kind of an hybrid recursion as the
     * Flow is effectively iterating and recurring over its
     * Nodes, which may as well be seen as over itself
     *
     * Iterating tends to limit the amount of recursion levels:
     * recursion is only triggered when executing a Traversable
     * Node's downstream Nodes while every consecutive exec
     * Nodes are executed within a while loop.
     * And recursion keeps the size of the recursion context
     * to a minimum as pretty much everything is done by the
     * iterating instance
     *
     * @param mixed $param
     * @param int   $nodeIdx
     *
     * @return mixed the last value returned by the last
     *               returning value Node in the flow
     */
    protected function recurse($param = null, $nodeIdx = 0)
    {
        while ($nodeIdx <= $this->lastIdx) {
            $node      = $this->nodes[$nodeIdx];
            $nodeStats = &$this->flowMap->getNodeStat($node->getId());

            $returnVal = $node->isReturningVal();

            if ($node->isTraversable()) {
                /** @var TraversableNodeInterface $node */
                foreach ($node->getTraversable($param) as $value) {
                    if ($returnVal) {
                        // pass current $value as next param
                        $param = $value;
                    }

                    ++$nodeStats['num_iterate'];
                    ++$this->numIterate;
                    if (!($this->numIterate % $this->progressMod)) {
                        $this->triggerCallback(static::FLOW_PROGRESS, $node);
                    }

                    $param = $this->recurse($param, $nodeIdx + 1);
                    if ($this->continue) {
                        if ($this->continue = $this->interruptNode($node)) {
                            // since we want to bubble the continue upstream
                            // we break here waiting for next $param if any
                            ++$nodeStats['num_break'];
                            break;
                        }

                        // we drop one iteration
                        ++$nodeStats['num_continue'];
                        continue;
                    }

                    if ($this->break) {
                        // we drop all subsequent iterations
                        ++$nodeStats['num_break'];
                        $this->break = $this->interruptNode($node);
                        break;
                    }
                }

                // we reached the end of this Traversable and executed all its downstream Nodes
                ++$nodeStats['num_exec'];

                return $param;
            }

            /** @var ExecNodeInterface $node */
            $value = $node->exec($param);
            ++$nodeStats['num_exec'];

            if ($this->continue) {
                ++$nodeStats['num_continue'];
                // a continue does not need to bubble up unless
                // it specifically targets a node in this flow
                // or targets an upstream flow
                $this->continue = $this->interruptNode($node);

                return $param;
            }

            if ($this->break) {
                ++$nodeStats['num_break'];
                // a break always need to bubble up to the first upstream Traversable if any
                return $param;
            }

            if ($returnVal) {
                // pass current $value as next param
                $param = $value;
            }

            ++$nodeIdx;
        }

        // we reached the end of this recursion
        return $param;
    }

    /**
     * KISS helper to trigger Callback slots
     *
     * @param string             $which
     * @param null|NodeInterface $node
     *
     * @return $this
     */
    protected function triggerCallback($which, NodeInterface $node = null)
    {
        if (null !== $this->callBack) {
            $this->callBack->$which($this, $node);
        }

        return $this;
    }
}


1			<?php
2
3			/*
4			* This file is part of NodalFlow.
5			* (c) Fabrice de Stefanis / https://github.com/fab2s/NodalFlow
6			* This source file is licensed under the MIT license which you will
7			* find in the LICENSE file or at https://opensource.org/licenses/MIT
8			*/
9
10			namespace fab2s\NodalFlow;
11
12			use fab2s\NodalFlow\Callbacks\CallbackInterface;
13			use fab2s\NodalFlow\Flows\FlowAbstract;
14			use fab2s\NodalFlow\Flows\FlowMap;
15			use fab2s\NodalFlow\Flows\FlowStatus;
16			use fab2s\NodalFlow\Flows\InterrupterInterface;
17			use fab2s\NodalFlow\Nodes\BranchNodeInterface;
18			use fab2s\NodalFlow\Nodes\ExecNodeInterface;
19			use fab2s\NodalFlow\Nodes\NodeInterface;
20			use fab2s\NodalFlow\Nodes\TraversableNodeInterface;
21
22			/**
23			* Class NodalFlow
24			*/
25			class NodalFlow extends FlowAbstract
26			{
27			/**
28			* Flow steps triggering callbacks
29			*/
30			const FLOW_START = 'start';
31			const FLOW_PROGRESS = 'progress';
32			const FLOW_SUCCESS = 'success';
33			const FLOW_FAIL = 'fail';
34
35			/**
36			* @var array
37			*/
38			protected $flowIncrements = [];
39
40			/**
41			* The current Node index
42			*
43			* @var int
44			*/
45			protected $nodeIdx = 0;
46
47			/**
48			* The last index value
49			*
50			* @var int
51			*/
52			protected $lastIdx = 0;
53
54			/**
55			* The number of Node in this Flow
56			*
57			* @var int
58			*/
59			protected $nodeCount = 0;
60
61			/**
62			* The number of iteration within this Flow
63			*
64			* @var int
65			*/
66			protected $numIterate = 0;
67
68			/**
69			* The current registered Callback class if any
70			*
71			* @var CallbackInterface\|null
72			*/
73			protected $callBack;
74
75			/**
76			* Instantiate a Flow
77			*/
78			public function __construct()
79			{
80			$this->flowMap = new FlowMap($this, $this->flowIncrements);
81			}
82
83			/**
84			* Adds a Node to the flow
85			*
86			* @param NodeInterface $node
87			*
88			* @throws NodalFlowException
89			*
90			* @return $this
91			*/
92			public function add(NodeInterface $node)
93			{
94			if ($node instanceof BranchNodeInterface) {
95			// this node is a branch, set it's parent
96			$node->getPayload()->setParent($this);
97			}
98
99			$node->setCarrier($this);
100
101			$this->flowMap->register($node, $this->nodeIdx);
102			$this->nodes[$this->nodeIdx] = $node;
103
104			++$this->nodeIdx;
105
106			return $this;
107			}
108
109			/**
110			* Adds a Payload Node to the Flow
111			*
112			* @param callable $payload
113			* @param mixed $isAReturningVal
114			* @param mixed $isATraversable
115			*
116			* @return $this
117			*/
118			public function addPayload(callable $payload, $isAReturningVal, $isATraversable = false)
119			{
120			$node = PayloadNodeFactory::create($payload, $isAReturningVal, $isATraversable);
121
122			$this->add($node);
123
124			return $this;
125			}
126
127			/**
128			* Register callback class
129			*
130			* @param CallbackInterface $callBack
131			*
132			* @return $this
133			*/
134			public function setCallBack(CallbackInterface $callBack)
135			{
136			$this->callBack = $callBack;
137
138			return $this;
139			}
140
141			/**
142			* Execute the flow
143			*
144			* @param null\|mixed $param The eventual init argument to the first node
145			* or, in case of a branch, the last relevant
146			* argument from upstream Flow
147			*
148			* @throws NodalFlowException
149			*
150			* @return mixed the last result of the
151			* last returning value node
152			*/
153			public function exec($param = null)
154			{
155			try {
156			$result = $this->rewind()
157			->flowStart()
158			->recurse($param);
159
160			// set flowStatus to make sure that we have the proper
161			// value in flowEnd even when overridden without (or when
162			// improperly) calling parent
163			if ($this->flowStatus->isRunning()) {
164			$this->flowStatus = new FlowStatus(FlowStatus::FLOW_CLEAN);
165			}
166
167			$this->flowEnd();
168
169			return $result;
170			} catch (\Exception $e) {
171			$this->flowStatus = new FlowStatus(FlowStatus::FLOW_EXCEPTION);
172			$this->flowEnd();
173			if ($e instanceof NodalFlowException) {
174			throw $e;
175			}
176
177			throw new NodalFlowException('Flow execution failed', 0, $e, [
178			'nodeMap' => $this->getNodeMap(),
179			]);
180			}
181			}
182
183			/**
184			* Rewinds the Flow
185			*
186			* @return $this
187			*/
188			public function rewind()
189			{
190			$this->nodeCount = count($this->nodes);
191			$this->lastIdx = $this->nodeCount - 1;
192			$this->break = false;
193			$this->continue = false;
194			$this->interruptNodeId = null;
195
196			return $this;
197			}
198
199			/**
200			* Break the flow's execution, conceptually similar to breaking
201			* a regular loop
202			*
203			* @param InterrupterInterface\|null $flowInterrupt
204			*
205			* @return $this
206			*/
207			public function breakFlow(InterrupterInterface $flowInterrupt = null)
208			{
209			return $this->interruptFlow(InterrupterInterface::TYPE_BREAK, $flowInterrupt);
210			}
211
212			/**
213			* Continue the flow's execution, conceptually similar to continuing
214			* a regular loop
215			*
216			* @param InterrupterInterface\|null $flowInterrupt
217			*
218			* @return $this
219			*/
220			public function continueFlow(InterrupterInterface $flowInterrupt = null)
221			{
222			return $this->interruptFlow(InterrupterInterface::TYPE_CONTINUE, $flowInterrupt);
223			}
224
225			/**
226			* Triggered just before the flow starts
227			*
228			* @return $this
229			*/
230			protected function flowStart()
231			{
232			$this->flowMap->incrementFlow('num_exec')->flowStart();
233			$this->triggerCallback(static::FLOW_START);
234
235			// flow is started
236			$this->flowStatus = new FlowStatus(FlowStatus::FLOW_RUNNING);
237
238			return $this;
239			}
240
241			/**
242			* Triggered right after the flow stops
243			*
244			* @return $this
245			*/
246			protected function flowEnd()
247			{
248			$this->flowMap->flowEnd();
249
250			$this->triggerCallback($this->flowStatus->isException() ? static::FLOW_FAIL : static::FLOW_SUCCESS);
251
252			return $this;
253			}
254
255			/**
256			* Recurse over nodes which may as well be Flows and
257			* Traversable ...
258			* Welcome to the abysses of recursion or iter-recursion ^^
259			*
260			* `recurse` perform kind of an hybrid recursion as the
261			* Flow is effectively iterating and recurring over its
262			* Nodes, which may as well be seen as over itself
263			*
264			* Iterating tends to limit the amount of recursion levels:
265			* recursion is only triggered when executing a Traversable
266			* Node's downstream Nodes while every consecutive exec
267			* Nodes are executed within a while loop.
268			* And recursion keeps the size of the recursion context
269			* to a minimum as pretty much everything is done by the
270			* iterating instance
271			*
272			* @param mixed $param
273			* @param int $nodeIdx
274			*
275			* @return mixed the last value returned by the last
276			* returning value Node in the flow
277			*/
278			protected function recurse($param = null, $nodeIdx = 0)
279			{
280			while ($nodeIdx <= $this->lastIdx) {
281			$node = $this->nodes[$nodeIdx];
282			$nodeStats = &$this->flowMap->getNodeStat($node->getId());
283
284			$returnVal = $node->isReturningVal();
285
286			if ($node->isTraversable()) {
287			/** @var TraversableNodeInterface $node */
288			foreach ($node->getTraversable($param) as $value) {
289			if ($returnVal) {
290			// pass current $value as next param
291			$param = $value;
292			}
293
294			++$nodeStats['num_iterate'];
295			++$this->numIterate;
296			if (!($this->numIterate % $this->progressMod)) {
297			$this->triggerCallback(static::FLOW_PROGRESS, $node);
298			}
299
300			$param = $this->recurse($param, $nodeIdx + 1);
301			if ($this->continue) {
302			if ($this->continue = $this->interruptNode($node)) {
303			// since we want to bubble the continue upstream
304			// we break here waiting for next $param if any
305			++$nodeStats['num_break'];
306			break;
307			}
308
309			// we drop one iteration
310			++$nodeStats['num_continue'];
311			continue;
312			}
313
314			if ($this->break) {
315			// we drop all subsequent iterations
316			++$nodeStats['num_break'];
317			$this->break = $this->interruptNode($node);
318			break;
319			}
320			}
321
322			// we reached the end of this Traversable and executed all its downstream Nodes
323			++$nodeStats['num_exec'];
324
325			return $param;
326			}
327
328			/** @var ExecNodeInterface $node */
329			$value = $node->exec($param);
330			++$nodeStats['num_exec'];
331
332			if ($this->continue) {
333			++$nodeStats['num_continue'];
334			// a continue does not need to bubble up unless
335			// it specifically targets a node in this flow
336			// or targets an upstream flow
337			$this->continue = $this->interruptNode($node);
338
339			return $param;
340			}
341
342			if ($this->break) {
343			++$nodeStats['num_break'];
344			// a break always need to bubble up to the first upstream Traversable if any
345			return $param;
346			}
347
348			if ($returnVal) {
349			// pass current $value as next param
350			$param = $value;
351			}
352
353			++$nodeIdx;
354			}
355
356			// we reached the end of this recursion
357			return $param;
358			}
359
360			/**
361			* KISS helper to trigger Callback slots
362			*
363			* @param string $which
364			* @param null\|NodeInterface $node
365			*
366			* @return $this
367			*/
368			protected function triggerCallback($which, NodeInterface $node = null)
369			{
370			if (null !== $this->callBack) {
371			$this->callBack->$which($this, $node);
372			}
373
374			return $this;
375			}
376			}
377

fab2s / NodalFlow

Pull Request — master (#1)

NodalFlow::interruptFlow() B

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