+<?php
+/**
+ * A general file-based stack class
+ *
+ * @author Roland Haeder <webmaster@ship-simu.org>
+ * @version 0.0.0
+ * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2013 Core Developer Team
+ * @license GNU GPL 3.0 or any newer version
+ * @link http://www.ship-simu.org
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+class BaseFileStack extends BaseStacker {
+ /**
+ * Magic for this stack
+ */
+ const STACK_MAGIC = 'STACKv0.1';
+
+ /**
+ * Separator magic->count
+ */
+ const SEPARATOR_MAGIC_COUNT = 0x00;
+
+ /**
+ * Separator position->entries
+ */
+ const SEPARATOR_SEEK_POS_ENTRIES = 0xff;
+
+ /**
+ * Separator hash->name
+ */
+ const SEPARATOR_HASH_NAME = 0x05;
+
+ /**
+ * Protected constructor
+ *
+ * @param $className Name of the class
+ * @return void
+ */
+ protected function __construct ($className) {
+ // Call parent constructor
+ parent::__construct($className);
+ }
+
+ /**
+ * Checks whether the file header is initialized
+ *
+ * @return $isInitialized Whether the file header is initialized
+ */
+ private function isFileHeaderInitialized () {
+ // Default is not initialized
+ $isInitialized = FALSE;
+
+ // Is the file initialized?
+ if ($this->isFileInitialized()) {
+ // Some bytes has been written, so rewind to start of it.
+ $this->getIteratorInstance()->rewind();
+
+ // Read file header
+ $this->readFileHeader();
+ } // END - if
+
+ // Return result
+ return $isInitialized;
+ }
+
+ /**
+ * Checks whether the file-based stack has been initialized
+ *
+ * @return $isInitialized Whether the file's size is zero
+ */
+ private function isFileInitialized () {
+ // Default is not initialized
+ $isInitialized = FALSE;
+
+ // Get it from iterator which holds the pointer instance. If FALSE is returned
+ $fileSize = $this->getIteratorInstance()->size();
+
+ /*
+ * The returned file size should not be FALSE or NULL as this means
+ * that the pointer class does not work correctly.
+ */
+ assert(is_int($fileSize));
+
+ // Is more than 0 returned?
+ if ($fileSize > 0) {
+ // So is the header written?
+ $isInitialized = $this->getIteratorInstance()->isHeaderInitialized();
+ } // END - if
+
+ // Return result
+ return $isInitialized;
+ }
+
+ /**
+ * Initializes this file-based stack.
+ *
+ * @param $fileName File name of this stack
+ * @return void
+ */
+ protected function initFileStack ($fileName) {
+ // Get a file i/o pointer instance
+ $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
+
+ // Get iterator instance
+ $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
+
+ // Is the instance implementing the right interface?
+ assert($iteratorInstance instanceof SeekableWritableFileIterator);
+
+ // Set iterator here
+ $this->setIteratorInstance($iteratorInstance);
+
+ // Is the file's header initialized?
+ if ($this->isFileHeaderInitialized()) {
+ // Then load it
+ $this->loadFileHeader();
+ } else {
+ // No, then create it (which may pre-allocate the stack)
+ $this->createFileHeader();
+ }
+ }
+
+ /**
+ * Initializes given stacker
+ *
+ * @param $stackerName Name of the stack
+ * @param $forceReInit Force re-initialization
+ * @return void
+ * @throws AlreadyInitializedStackerException If the stack is already initialized
+ */
+ public function initStack ($stackerName, $forceReInit = FALSE) {
+ // Is the stack already initialized?
+ if (($forceReInit === FALSE) && ($this->isStackInitialized($stackerName))) {
+ // Then throw the exception
+ throw new AlreadyInitializedStackerException(array($this, $stackerName, $forceReInit), self::EXCEPTION_STACKER_ALREADY_INITIALIZED);
+ } // END - if
+
+ // Initialize the given stack
+ $this->partialStub('stackerName=' . $stackerName . ',forceReInit=' . intval($forceReInit));
+ }
+
+ /**
+ * Checks whether the given stack is initialized (set in array $stackers)
+ *
+ * @param $stackerName Name of the stack
+ * @return $isInitialized Whether the stack is initialized
+ */
+ public function isStackInitialized ($stackerName) {
+ // Is is there?
+ $this->partialStub('stackerName=' . $stackerName);
+ $isInitialized = TRUE;
+
+ // Return result
+ return $isInitialized;
+ }
+
+ /**
+ * Getter for size of given stack (array count)
+ *
+ * @param $stackerName Name of the stack
+ * @return $count Size of stack (array count)
+ * @throws NoStackerException If given stack is missing
+ */
+ public function getStackCount ($stackerName) {
+ // Is the stack not yet initialized?
+ if (!$this->isStackInitialized($stackerName)) {
+ // Throw an exception
+ throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
+ } // END - if
+
+ // Now, count the array of entries
+ $this->partialStub('stackerName=' . $stackerName);
+ $count = 0;
+
+ // Return result
+ return $count;
+ }
+
+ /**
+ * Adds a value to given stack
+ *
+ * @param $stackerName Name of the stack
+ * @param $value Value to add to this stacker
+ * @return void
+ * @throws FullStackerException Thrown if the stack is full
+ */
+ protected function addValue ($stackerName, $value) {
+ // Is the stack not yet initialized or full?
+ if (!$this->isStackInitialized($stackerName)) {
+ // Then do it here
+ $this->initStack($stackerName);
+ } elseif ($this->isStackFull($stackerName)) {
+ // Stacker is full
+ throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
+ }
+
+ // Now add the value to the stack
+ $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
+ }
+
+ /**
+ * Get last value from named stacker
+ *
+ * @param $stackerName Name of the stack
+ * @return $value Value of last added value
+ * @throws NoStackerException If the named stacker was not found
+ * @throws EmptyStackerException If the named stacker is empty
+ */
+ protected function getLastValue ($stackerName) {
+ // Is the stack not yet initialized or full?
+ if (!$this->isStackInitialized($stackerName)) {
+ // Throw an exception
+ throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
+ } elseif ($this->isStackEmpty($stackerName)) {
+ // Throw an exception
+ throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
+ }
+
+ // Now get the last value
+ $this->partialStub('stackerName=' . $stackerName);
+ $value = NULL;
+
+ // Return it
+ return $value;
+ }
+
+ /**
+ * Get first value from named stacker
+ *
+ * @param $stackerName Name of the stack
+ * @return $value Value of last added value
+ * @throws NoStackerException If the named stacker was not found
+ * @throws EmptyStackerException If the named stacker is empty
+ */
+ protected function getFirstValue ($stackerName) {
+ // Is the stack not yet initialized or full?
+ if (!$this->isStackInitialized($stackerName)) {
+ // Throw an exception
+ throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
+ } elseif ($this->isStackEmpty($stackerName)) {
+ // Throw an exception
+ throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
+ }
+
+ // Now get the first value
+ $this->partialStub('stackerName=' . $stackerName);
+ $value = NULL;
+
+ // Return it
+ return $value;
+ }
+
+ /**
+ * "Pops" last entry from stack
+ *
+ * @param $stackerName Name of the stack
+ * @return $value Value "poped" from array
+ * @throws NoStackerException If the named stacker was not found
+ * @throws EmptyStackerException If the named stacker is empty
+ */
+ protected function popLast ($stackerName) {
+ // Is the stack not yet initialized or full?
+ if (!$this->isStackInitialized($stackerName)) {
+ // Throw an exception
+ throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
+ } elseif ($this->isStackEmpty($stackerName)) {
+ // Throw an exception
+ throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
+ }
+
+ // Now, remove the last entry, we don't care about the return value here, see elseif() block above
+ $this->partialStub('stackerName=' . $stackerName);
+ return NULL;
+ }
+
+ /**
+ * "Pops" first entry from stack
+ *
+ * @param $stackerName Name of the stack
+ * @return $value Value "shifted" from array
+ * @throws NoStackerException If the named stacker was not found
+ * @throws EmptyStackerException If the named stacker is empty
+ */
+ protected function popFirst ($stackerName) {
+ // Is the stack not yet initialized or full?
+ if (!$this->isStackInitialized($stackerName)) {
+ // Throw an exception
+ throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
+ } elseif ($this->isStackEmpty($stackerName)) {
+ // Throw an exception
+ throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
+ }
+
+ // Now, remove the last entry, we don't care about the return value here, see elseif() block above
+ $this->partialStub('stackerName=' . $stackerName);
+ return NULL;
+ }
+}
+
+// [EOF]
+?>
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