Issue #3103090 by greg.1.anderson, alexpott, jungle, ravi.shankar, dww, Mile23, larowlan: Avoid re-scaffolding unchanged files (and printing scaffold file information over and over)

Author: alexpott

Handler.php

@@ -154,11 +154,17 @@ public function scaffold() {
  $scaffold_options = $this->manageOptions->getOptions();
 
  // Create a collection of scaffolded files to process. This determines which
- // take priority and which are conjoined.
+ // take priority and which are combined.
  $scaffold_files = new ScaffoldFileCollection($file_mappings, $location_replacements);
 
+ // Get the scaffold files whose contents on disk match what we are about to
+ // write. We can remove these from consideration, as rewriting would be a
+ // no-op.
+ $unchanged = $scaffold_files->checkUnchanged();
+ $scaffold_files->filterFiles($unchanged);
+
  // Process the list of scaffolded files.
- $scaffold_results = ScaffoldFileCollection::process($scaffold_files, $this->io, $scaffold_options);
+ $scaffold_results = $scaffold_files->process($this->io, $scaffold_options);
 
  // Generate an autoload file in the document root that includes the
  // autoload.php file in the vendor directory, wherever that is. Drupal
@@ -195,7 +201,7 @@ protected function getVendorPath() {
  * A multidimensional array of file mappings, as returned by
  * self::getAllowedPackages().
  *
- * @return \Drupal\Composer\Plugin\Scaffold\Operations\OperationInterface[]
+ * @return \Drupal\Composer\Plugin\Scaffold\Operations\OperationInterface[][]
  * An array of destination paths => scaffold operation objects.
  */
  protected function getFileMappingsFromPackages(array $allowed_packages) {

Operations/AbstractOperation.php

@@ -11,17 +11,42 @@
  */
 abstract class AbstractOperation implements OperationInterface {
 
+ /**
+ * Cached contents of scaffold file to be written to disk.
+ *
+ * @var string
+ */
+ protected $contents;
+
+ /**
+ * {@inheritdoc}
+ */
+ final public function contents() {
+ if (!isset($this->contents)) {
+ $this->contents = $this->generateContents();
+ }
+ return $this->contents;
+ }
+
+ /**
+ * Load the scaffold contents or otherwise generate what is needed.
+ *
+ * @return string
+ * The contents of the scaffold file.
+ */
+ abstract protected function generateContents();
+
  /**
  * {@inheritdoc}
  */
- public function combineWithConjunctionTarget(OperationInterface $conjunction_target) {
+ public function scaffoldOverExistingTarget(OperationInterface $existing_target) {
  return $this;
  }
 
  /**
  * {@inheritdoc}
  */
- public function missingConjunctionTarget(ScaffoldFilePath $destination) {
+ public function scaffoldAtNewLocation(ScaffoldFilePath $destination) {
  return $this;
  }
 

Operations/AppendOp.php

@@ -49,6 +49,13 @@ class AppendOp extends AbstractOperation {
  */
  protected $forceAppend;
 
+ /**
+ * The contents from the file that we are prepending / appending to.
+ *
+ * @var string
+ */
+ protected $originalContents;
+
  /**
  * Constructs an AppendOp.
  *
@@ -69,16 +76,36 @@ public function __construct(ScaffoldFilePath $prepend_path = NULL, ScaffoldFileP
  $this->managed = TRUE;
  }
 
+ /**
+ * {@inheritdoc}
+ */
+ protected function generateContents() {
+ // Fetch the prepend contents, if provided.
+ $prepend_contents = '';
+ if (!empty($this->prepend)) {
+ $prepend_contents = file_get_contents($this->prepend->fullPath()) . "\n";
+ }
+ // Fetch the append contents, if provided.
+ $append_contents = '';
+ if (!empty($this->append)) {
+ $append_contents = "\n" . file_get_contents($this->append->fullPath());
+ }
+
+ // Get the original contents, or the default data if the original is empty.
+ $original_contents = $this->originalContents;
+ if (empty($original_contents) && !empty($this->default)) {
+ $original_contents = file_get_contents($this->default->fullPath());
+ }
+
+ // Attach it all together.
+ return $prepend_contents . $original_contents . $append_contents;
+ }
+
  /**
  * {@inheritdoc}
  */
  public function process(ScaffoldFilePath $destination, IOInterface $io, ScaffoldOptions $options) {
  $destination_path = $destination->fullPath();
- // This is just a sanity check; the OperationFactory has in theory already
- // accounted for this, and will return a SkipOp with a warning message.
- if (!file_exists($destination_path) && empty($this->default)) {
- throw new \RuntimeException($destination->getInterpolator()->interpolate("Cannot append/prepend because no prior package provided a scaffold file at [dest-rel-path]."));
- }
  $interpolator = $destination->getInterpolator();
 
  // Be extra-noisy of creating a new file or appending to a non-scaffold
@@ -93,33 +120,20 @@ public function process(ScaffoldFilePath $destination, IOInterface $io, Scaffold
  $io->write($interpolator->interpolate($message));
  }
 
- // Fetch the prepend contents, if provided.
- $prepend_contents = '';
+ // Notify that we are prepending, if there is prepend data.
  if (!empty($this->prepend)) {
  $this->prepend->addInterpolationData($interpolator, 'prepend');
- $prepend_contents = file_get_contents($this->prepend->fullPath()) . "\n";
  $io->write($interpolator->interpolate(" - Prepend to <info>[dest-rel-path]</info> from <info>[prepend-rel-path]</info>"));
  }
- // Fetch the append contents, if provided.
+ // Notify that we are appending, if there is append data.
  $append_contents = '';
  if (!empty($this->append)) {
  $this->append->addInterpolationData($interpolator, 'append');
- $append_contents = "\n" . file_get_contents($this->append->fullPath());
  $io->write($interpolator->interpolate(" - Append to <info>[dest-rel-path]</info> from <info>[append-rel-path]</info>"));
  }
- // We typically should always have content if we get here; the
- // OperationFactory should create a SkipOp instead of an AppendOp if there
- // is no append / prepend content. The edge case is if there is content
- // that is all 'trim'ed away. Then we get a message that we are appending,
- // although nothing will in fact actually happen.
- if (!empty(trim($prepend_contents)) || !empty(trim($append_contents))) {
- // None of our asset files are very large, so we will load each one into
- // memory for processing.
- $original_contents = file_get_contents(file_exists($destination_path) ? $destination_path : $this->default->fullPath());
- // Write the appended and prepended contents back to the file.
- $altered_contents = $prepend_contents . $original_contents . $append_contents;
- file_put_contents($destination_path, $altered_contents);
- }
+
+ // Write the resulting data
+ file_put_contents($destination_path, $this->contents());
 
  // Return a ScaffoldResult with knowledge of whether this file is managed.
  return new ScaffoldResult($destination, $this->managed);
@@ -128,16 +142,17 @@ public function process(ScaffoldFilePath $destination, IOInterface $io, Scaffold
  /**
  * {@inheritdoc}
  */
- public function combineWithConjunctionTarget(OperationInterface $conjunction_target) {
- return new ConjunctionOp($conjunction_target, $this);
+ public function scaffoldOverExistingTarget(OperationInterface $existing_target) {
+ $this->originalContents = $existing_target->contents();
+ return $this;
  }
 
  /**
  * {@inheritdoc}
  */
- public function missingConjunctionTarget(ScaffoldFilePath $destination) {
- // If there is no conjunction target (the destination is not scaffolded),
- // then any append we do will be to an unmanaged file.
+ public function scaffoldAtNewLocation(ScaffoldFilePath $destination) {
+ // If there is no existing scaffold file at the target location, then any
+ // append we do will be to an unmanaged file.
  $this->managed = FALSE;
 
  // Default: do not allow an append over a file that was not scaffolded.
@@ -164,6 +179,9 @@ public function missingConjunctionTarget(ScaffoldFilePath $destination) {
  return new SkipOp($message);
  }
 
+ // Cache the original data to use during append.
+ $this->originalContents = $existingData;
+
  return $this;
  }
 

Operations/ConjunctionOp.php

@@ -13,6 +13,14 @@
  */
 interface OperationInterface {
 
+ /**
+ * Returns the exact data that will be written to the scaffold files.
+ *
+ * @return string
+ * Data to be written to the scaffold location.
+ */
+ public function contents();
+
  /**
  * Process this scaffold operation.
  *
@@ -29,18 +37,18 @@ interface OperationInterface {
  public function process(ScaffoldFilePath $destination, IOInterface $io, ScaffoldOptions $options);
 
  /**
- * Determines what to do if operation is used with a previous operation.
+ * Determines what to do if operation is used at same path as a previous op.
  *
  * Default behavior is to scaffold this operation at the specified
  * destination, ignoring whatever was there before.
  *
- * @param OperationInterface $conjunction_target
+ * @param OperationInterface $existing_target
  * Existing file at the destination path that we should combine with.
  *
  * @return OperationInterface
  * The op to use at this destination.
  */
- public function combineWithConjunctionTarget(OperationInterface $conjunction_target);
+ public function scaffoldOverExistingTarget(OperationInterface $existing_target);
 
  /**
  * Determines what to do if operation is used without a previous operation.
@@ -50,9 +58,12 @@ public function combineWithConjunctionTarget(OperationInterface $conjunction_tar
  * and therefore do not need to do anything special when there is no existing
  * file.
  *
+ * @param \Drupal\Composer\Plugin\Scaffold\ScaffoldFilePath $destination
+ * Scaffold file's destination path.
+ *
  * @return OperationInterface
  * The op to use at this destination.
  */
- public function missingConjunctionTarget(ScaffoldFilePath $destination);
+ public function scaffoldAtNewLocation(ScaffoldFilePath $destination);
 
 }

Operations/OperationInterface.php

@@ -47,6 +47,13 @@ public function __construct(ScaffoldFilePath $sourcePath, $overwrite = TRUE) {
  $this->overwrite = $overwrite;
  }
 
+ /**
+ * {@inheritdoc}
+ */
+ protected function generateContents() {
+ return file_get_contents($this->source->fullPath());
+ }
+
  /**
  * {@inheritdoc}
  */
@@ -85,8 +92,7 @@ public function process(ScaffoldFilePath $destination, IOInterface $io, Scaffold
  protected function copyScaffold(ScaffoldFilePath $destination, IOInterface $io) {
  $interpolator = $destination->getInterpolator();
  $this->source->addInterpolationData($interpolator);
- $fs = new Filesystem();
- $success = $fs->copy($this->source->fullPath(), $destination->fullPath());
+ $success = file_put_contents($destination->fullPath(), $this->contents());
  if (!$success) {
  throw new \RuntimeException($interpolator->interpolate("Could not copy source file <info>[src-rel-path]</info> to <info>[dest-rel-path]</info>!"));
  }