Add very basic support for generating PDF documents

Summary: Ref T13358. This is very minimal, but technically works. The eventual goal is to generate PDF invoices to make my life easier when I have to interact with Enterprise Vendor Procurement.

Test Plan: {F6672439}

Maniphest Tasks: T13358

Differential Revision: https://secure.phabricator.com/D20692

src/__phutil_library_map__.php

@@ -3878,7 +3878,21 @@ phutil_register_library_map(array(
     'PhabricatorOwnersPathsSearchEngineAttachment' => 'applications/owners/engineextension/PhabricatorOwnersPathsSearchEngineAttachment.php',
     'PhabricatorOwnersSchemaSpec' => 'applications/owners/storage/PhabricatorOwnersSchemaSpec.php',
     'PhabricatorOwnersSearchField' => 'applications/owners/searchfield/PhabricatorOwnersSearchField.php',
+    'PhabricatorPDFCatalogObject' => 'applications/phortune/pdf/PhabricatorPDFCatalogObject.php',
+    'PhabricatorPDFContentsObject' => 'applications/phortune/pdf/PhabricatorPDFContentsObject.php',
     'PhabricatorPDFDocumentEngine' => 'applications/files/document/PhabricatorPDFDocumentEngine.php',
+    'PhabricatorPDFFontObject' => 'applications/phortune/pdf/PhabricatorPDFFontObject.php',
+    'PhabricatorPDFFragment' => 'applications/phortune/pdf/PhabricatorPDFFragment.php',
+    'PhabricatorPDFFragmentOffset' => 'applications/phortune/pdf/PhabricatorPDFFragmentOffset.php',
+    'PhabricatorPDFGenerator' => 'applications/phortune/pdf/PhabricatorPDFGenerator.php',
+    'PhabricatorPDFHeadFragment' => 'applications/phortune/pdf/PhabricatorPDFHeadFragment.php',
+    'PhabricatorPDFInfoObject' => 'applications/phortune/pdf/PhabricatorPDFInfoObject.php',
+    'PhabricatorPDFIterator' => 'applications/phortune/pdf/PhabricatorPDFIterator.php',
+    'PhabricatorPDFObject' => 'applications/phortune/pdf/PhabricatorPDFObject.php',
+    'PhabricatorPDFPageObject' => 'applications/phortune/pdf/PhabricatorPDFPageObject.php',
+    'PhabricatorPDFPagesObject' => 'applications/phortune/pdf/PhabricatorPDFPagesObject.php',
+    'PhabricatorPDFResourcesObject' => 'applications/phortune/pdf/PhabricatorPDFResourcesObject.php',
+    'PhabricatorPDFTailFragment' => 'applications/phortune/pdf/PhabricatorPDFTailFragment.php',
     'PhabricatorPHDConfigOptions' => 'applications/config/option/PhabricatorPHDConfigOptions.php',
     'PhabricatorPHID' => 'applications/phid/storage/PhabricatorPHID.php',
     'PhabricatorPHIDConstants' => 'applications/phid/PhabricatorPHIDConstants.php',
@@ -10101,7 +10115,24 @@ phutil_register_library_map(array(
     'PhabricatorOwnersPathsSearchEngineAttachment' => 'PhabricatorSearchEngineAttachment',
     'PhabricatorOwnersSchemaSpec' => 'PhabricatorConfigSchemaSpec',
     'PhabricatorOwnersSearchField' => 'PhabricatorSearchTokenizerField',
+    'PhabricatorPDFCatalogObject' => 'PhabricatorPDFObject',
+    'PhabricatorPDFContentsObject' => 'PhabricatorPDFObject',
     'PhabricatorPDFDocumentEngine' => 'PhabricatorDocumentEngine',
+    'PhabricatorPDFFontObject' => 'PhabricatorPDFObject',
+    'PhabricatorPDFFragment' => 'Phobject',
+    'PhabricatorPDFFragmentOffset' => 'Phobject',
+    'PhabricatorPDFGenerator' => 'Phobject',
+    'PhabricatorPDFHeadFragment' => 'PhabricatorPDFFragment',
+    'PhabricatorPDFInfoObject' => 'PhabricatorPDFObject',
+    'PhabricatorPDFIterator' => array(
+      'Phobject',
+      'Iterator',
+    ),
+    'PhabricatorPDFObject' => 'PhabricatorPDFFragment',
+    'PhabricatorPDFPageObject' => 'PhabricatorPDFObject',
+    'PhabricatorPDFPagesObject' => 'PhabricatorPDFObject',
+    'PhabricatorPDFResourcesObject' => 'PhabricatorPDFObject',
+    'PhabricatorPDFTailFragment' => 'PhabricatorPDFFragment',
     'PhabricatorPHDConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorPHID' => 'Phobject',
     'PhabricatorPHIDConstants' => 'Phobject',

src/applications/phortune/pdf/PhabricatorPDFCatalogObject.php

@@ -0,0 +1,26 @@
+<?php
+
+final class PhabricatorPDFCatalogObject
+  extends PhabricatorPDFObject {
+
+  private $pagesObject;
+
+  public function setPagesObject(PhabricatorPDFPagesObject $pages_object) {
+    $this->pagesObject = $this->newChildObject($pages_object);
+    return $this;
+  }
+
+  public function getPagesObject() {
+    return $this->pagesObject;
+  }
+
+  protected function writeObject() {
+    $this->writeLine('/Type /Catalog');
+
+    $pages_object = $this->getPagesObject();
+    if ($pages_object) {
+      $this->writeLine('/Pages %d 0 R', $pages_object->getObjectIndex());
+    }
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFContentsObject.php

@@ -0,0 +1,25 @@
+<?php
+
+final class PhabricatorPDFContentsObject
+  extends PhabricatorPDFObject {
+
+  private $rawContent;
+
+  public function setRawContent($raw_content) {
+    $this->rawContent = $raw_content;
+    return $this;
+  }
+
+  public function getRawContent() {
+    return $this->rawContent;
+  }
+
+  protected function writeObject() {
+    $data = $this->getRawContent();
+
+    $stream_length = $this->newStream($data);
+
+    $this->writeLine('/Filter /FlateDecode /Length %d', $stream_length);
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFFontObject.php

@@ -0,0 +1,14 @@
+<?php
+
+final class PhabricatorPDFFontObject
+  extends PhabricatorPDFObject {
+
+  protected function writeObject() {
+    $this->writeLine('/Type /Font');
+
+    $this->writeLine('/BaseFont /Helvetica-Bold');
+    $this->writeLine('/Subtype /Type1');
+    $this->writeLine('/Encoding /WinAnsiEncoding');
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFFragment.php

@@ -0,0 +1,38 @@
+<?php
+
+abstract class PhabricatorPDFFragment
+  extends Phobject {
+
+  private $rope;
+
+  public function getAsBytes() {
+    $this->rope = new PhutilRope();
+
+    $this->writeFragment();
+
+    $rope = $this->rope;
+    $this->rope = null;
+
+    return $rope->getAsString();
+  }
+
+  public function hasRefTableEntry() {
+    return false;
+  }
+
+  abstract protected function writeFragment();
+
+  final protected function writeLine($pattern) {
+    $pattern = $pattern."\n";
+
+    $argv = func_get_args();
+    $argv[0] = $pattern;
+
+    $line = call_user_func_array('sprintf', $argv);
+
+    $this->rope->append($line);
+
+    return $this;
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFFragmentOffset.php

@@ -0,0 +1,27 @@
+<?php
+
+final class PhabricatorPDFFragmentOffset
+  extends Phobject {
+
+  private $fragment;
+  private $offset;
+
+  public function setFragment(PhabricatorPDFFragment $fragment) {
+    $this->fragment = $fragment;
+    return $this;
+  }
+
+  public function getFragment() {
+    return $this->fragment;
+  }
+
+  public function setOffset($offset) {
+    $this->offset = $offset;
+    return $this;
+  }
+
+  public function getOffset() {
+    return $this->offset;
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFGenerator.php

@@ -0,0 +1,59 @@
+<?php
+
+final class PhabricatorPDFGenerator
+  extends Phobject {
+
+  private $objects = array();
+  private $hasIterator = false;
+
+  private $infoObject;
+  private $catalogObject;
+
+  public function addObject(PhabricatorPDFObject $object) {
+    if ($this->hasIterator) {
+      throw new Exception(
+        pht(
+          'This generator has already emitted an iterator. You can not '.
+          'modify the PDF document after you begin writing it.'));
+    }
+
+    $this->objects[] = $object;
+    $index = count($this->objects);
+
+    $object->setGenerator($this, $index);
+
+    return $this;
+  }
+
+  public function getObjects() {
+    return $this->objects;
+  }
+
+  public function newIterator() {
+    $this->hasIterator = true;
+    return id(new PhabricatorPDFIterator())
+      ->setGenerator($this);
+  }
+
+  public function setInfoObject(PhabricatorPDFInfoObject $info_object) {
+    $this->addObject($info_object);
+    $this->infoObject = $info_object;
+    return $this;
+  }
+
+  public function getInfoObject() {
+    return $this->infoObject;
+  }
+
+  public function setCatalogObject(
+    PhabricatorPDFCatalogObject $catalog_object) {
+    $this->addObject($catalog_object);
+    $this->catalogObject = $catalog_object;
+    return $this;
+  }
+
+  public function getCatalogObject() {
+    return $this->catalogObject;
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFHeadFragment.php

@@ -0,0 +1,10 @@
+<?php
+
+final class PhabricatorPDFHeadFragment
+  extends PhabricatorPDFFragment {
+
+  protected function writeFragment() {
+    $this->writeLine('%s', '%PDF-1.3');
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFInfoObject.php

@@ -0,0 +1,11 @@
+<?php
+
+final class PhabricatorPDFInfoObject
+  extends PhabricatorPDFObject {
+
+  final protected function writeObject() {
+    $this->writeLine('/Producer (Phabricator 20190801)');
+    $this->writeLine('/CreationDate (D:%s)', date('YmdHis'));
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFIterator.php

@@ -0,0 +1,103 @@
+<?php
+
+final class PhabricatorPDFIterator
+  extends Phobject
+  implements Iterator {
+
+  private $generator;
+  private $hasRewound;
+
+  private $fragments;
+  private $fragmentKey;
+  private $fragmentBytes;
+  private $fragmentOffsets = array();
+  private $byteLength;
+
+  public function setGenerator(PhabricatorPDFGenerator $generator) {
+    if ($this->generator) {
+      throw new Exception(
+        pht(
+          'This iterator already has a generator. You can not modify the '.
+          'generator for a given iterator.'));
+    }
+
+    $this->generator = $generator;
+
+    return $this;
+  }
+
+  public function getGenerator() {
+    if (!$this->generator) {
+      throw new Exception(
+        pht(
+          'This PDF iterator has no associated PDF generator.'));
+    }
+
+    return $this->generator;
+  }
+
+  public function getFragmentOffsets() {
+    return $this->fragmentOffsets;
+  }
+
+  public function current() {
+    return $this->fragmentBytes;
+  }
+
+  public function key() {
+    return $this->framgentKey;
+  }
+
+  public function next() {
+    $this->fragmentKey++;
+
+    if (!$this->valid()) {
+      return;
+    }
+
+    $fragment = $this->fragments[$this->fragmentKey];
+
+    $this->fragmentOffsets[] = id(new PhabricatorPDFFragmentOffset())
+      ->setFragment($fragment)
+      ->setOffset($this->byteLength);
+
+    $bytes = $fragment->getAsBytes();
+
+    $this->fragmentBytes = $bytes;
+    $this->byteLength += strlen($bytes);
+  }
+
+  public function rewind() {
+    if ($this->hasRewound) {
+      throw new Exception(
+        pht(
+          'PDF iterators may not be rewound. Create a new iterator to emit '.
+          'another PDF.'));
+    }
+
+    $generator = $this->getGenerator();
+    $objects = $generator->getObjects();
+
+    $this->fragments = array();
+    $this->fragments[] = new PhabricatorPDFHeadFragment();
+
+    foreach ($objects as $object) {
+      $this->fragments[] = $object;
+    }
+
+    $this->fragments[] = id(new PhabricatorPDFTailFragment())
+      ->setIterator($this);
+
+    $this->hasRewound = true;
+
+    $this->fragmentKey = -1;
+    $this->byteLength = 0;
+
+    $this->next();
+  }
+
+  public function valid() {
+    return isset($this->fragments[$this->fragmentKey]);
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFObject.php

@@ -0,0 +1,95 @@
+<?php
+
+abstract class PhabricatorPDFObject
+  extends PhabricatorPDFFragment {
+
+  private $generator;
+  private $objectIndex;
+  private $children = array();
+  private $streams = array();
+
+  final public function hasRefTableEntry() {
+    return true;
+  }
+
+  final protected function writeFragment() {
+    $this->writeLine('%d 0 obj', $this->getObjectIndex());
+    $this->writeLine('<<');
+    $this->writeObject();
+    $this->writeLine('>>');
+
+    $streams = $this->streams;
+    $this->streams = array();
+    foreach ($streams as $stream) {
+      $this->writeLine('stream');
+      $this->writeLine('%s', $stream);
+      $this->writeLine('endstream');
+    }
+
+    $this->writeLine('endobj');
+  }
+
+  final public function setGenerator(
+    PhabricatorPDFGenerator $generator,
+    $index) {
+
+    if ($this->getGenerator()) {
+      throw new Exception(
+        pht(
+          'This PDF object is already registered with a PDF generator. You '.
+          'can not register an object with more than one generator.'));
+    }
+
+    $this->generator = $generator;
+    $this->objectIndex = $index;
+
+    foreach ($this->getChildren() as $child) {
+      $generator->addObject($child);
+    }
+
+    return $this;
+  }
+
+  final public function getGenerator() {
+    return $this->generator;
+  }
+
+  final public function getObjectIndex() {
+    if (!$this->objectIndex) {
+      throw new Exception(
+        pht(
+          'Trying to get index for object ("%s") which has not been '.
+          'registered with a generator.',
+          get_class($this)));
+    }
+
+    return $this->objectIndex;
+  }
+
+  final protected function newChildObject(PhabricatorPDFObject $object) {
+    if ($this->generator) {
+      throw new Exception(
+        pht(
+          'Trying to add a new PDF Object child after already registering '.
+          'the object with a generator.'));
+    }
+
+    $this->children[] = $object;
+    return $object;
+  }
+
+  private function getChildren() {
+    return $this->children;
+  }
+
+  abstract protected function writeObject();
+
+  final protected function newStream($raw_data) {
+    $stream_data = gzcompress($raw_data);
+
+    $this->streams[] = $stream_data;
+
+    return strlen($stream_data);
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFPageObject.php

@@ -0,0 +1,48 @@
+<?php
+
+final class PhabricatorPDFPageObject
+  extends PhabricatorPDFObject {
+
+  private $pagesObject;
+  private $contentsObject;
+  private $resourcesObject;
+
+  public function setPagesObject(PhabricatorPDFPagesObject $pages) {
+    $this->pagesObject = $pages;
+    return $this;
+  }
+
+  public function setContentsObject(PhabricatorPDFContentsObject $contents) {
+    $this->contentsObject = $this->newChildObject($contents);
+    return $this;
+  }
+
+  public function setResourcesObject(PhabricatorPDFResourcesObject $resources) {
+    $this->resourcesObject = $this->newChildObject($resources);
+    return $this;
+  }
+
+  protected function writeObject() {
+    $this->writeLine('/Type /Page');
+
+    $pages_object = $this->pagesObject;
+    $contents_object = $this->contentsObject;
+    $resources_object = $this->resourcesObject;
+
+    if ($pages_object) {
+      $pages_index = $pages_object->getObjectIndex();
+      $this->writeLine('/Parent %d 0 R', $pages_index);
+    }
+
+    if ($contents_object) {
+      $contents_index = $contents_object->getObjectIndex();
+      $this->writeLine('/Contents %d 0 R', $contents_index);
+    }
+
+    if ($resources_object) {
+      $resources_index = $resources_object->getObjectIndex();
+      $this->writeLine('/Resources %d 0 R', $resources_index);
+    }
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFPagesObject.php

@@ -0,0 +1,38 @@
+<?php
+
+final class PhabricatorPDFPagesObject
+  extends PhabricatorPDFObject {
+
+  private $pageObjects = array();
+
+  public function addPageObject(PhabricatorPDFPageObject $page) {
+    $page->setPagesObject($this);
+    $this->pageObjects[] = $this->newChildObject($page);
+    return $this;
+  }
+
+  public function getPageObjects() {
+    return $this->pageObjects;
+  }
+
+  protected function writeObject() {
+    $this->writeLine('/Type /Pages');
+
+    $page_objects = $this->getPageObjects();
+
+    $this->writeLine('/Count %d', count($page_objects));
+    $this->writeLine('/MediaBox [%d %d %0.2f %0.2f]', 0, 0, 595.28, 841.89);
+
+    if ($page_objects) {
+      $kids = array();
+      foreach ($page_objects as $page_object) {
+        $kids[] = sprintf(
+          '%d 0 R',
+          $page_object->getObjectIndex());
+      }
+
+      $this->writeLine('/Kids [%s]', implode(' ', $kids));
+    }
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFResourcesObject.php

@@ -0,0 +1,28 @@
+<?php
+
+final class PhabricatorPDFResourcesObject
+  extends PhabricatorPDFObject {
+
+  private $fontObjects = array();
+
+  public function addFontObject(PhabricatorPDFFontObject $font) {
+    $this->fontObjects[] = $this->newChildObject($font);
+    return $this;
+  }
+
+  public function getFontObjects() {
+    return $this->fontObjects;
+  }
+
+  protected function writeObject() {
+    $this->writeLine('/ProcSet [/PDF /Text /ImageB /ImageC /ImageI]');
+
+    $fonts = $this->getFontObjects();
+    foreach ($fonts as $font) {
+      $this->writeLine('/Font <<');
+      $this->writeLine('/F%d %d 0 R', 1, $font->getObjectIndex());
+      $this->writeLine('>>');
+    }
+  }
+
+}

src/applications/phortune/pdf/PhabricatorPDFTailFragment.php

@@ -0,0 +1,72 @@
+<?php
+
+final class PhabricatorPDFTailFragment
+  extends PhabricatorPDFFragment {
+
+  private $iterator;
+
+  public function setIterator(PhabricatorPDFIterator $iterator) {
+    $this->iterator = $iterator;
+    return $this;
+  }
+
+  public function getIterator() {
+    return $this->iterator;
+  }
+
+  protected function writeFragment() {
+    $iterator = $this->getIterator();
+    $generator = $iterator->getGenerator();
+    $objects = $generator->getObjects();
+
+    $xref_offset = null;
+
+    $this->writeLine('xref');
+    $this->writeLine('0 %d', count($objects) + 1);
+    $this->writeLine('%010d %05d f ', 0, 0xFFFF);
+
+    $offset_map = array();
+
+    $fragment_offsets = $iterator->getFragmentOffsets();
+    foreach ($fragment_offsets as $fragment_offset) {
+      $fragment = $fragment_offset->getFragment();
+      $offset = $fragment_offset->getOffset();
+
+      if ($fragment === $this) {
+        $xref_offset = $offset;
+      }
+
+      if (!$fragment->hasRefTableEntry()) {
+        continue;
+      }
+
+      $offset_map[$fragment->getObjectIndex()] = $offset;
+    }
+
+    ksort($offset_map);
+
+    foreach ($offset_map as $offset) {
+      $this->writeLine('%010d %05d n ', $offset, 0);
+    }
+
+    $this->writeLine('trailer');
+    $this->writeLine('<<');
+    $this->writeLine('/Size %d', count($objects) + 1);
+
+    $info_object = $generator->getInfoObject();
+    if ($info_object) {
+     $this->writeLine('/Info %d 0 R', $info_object->getObjectIndex());
+    }
+
+    $catalog_object = $generator->getCatalogObject();
+    if ($catalog_object) {
+      $this->writeLine('/Root %d 0 R', $catalog_object->getObjectIndex());
+    }
+
+    $this->writeLine('>>');
+    $this->writeLine('startxref');
+    $this->writeLine('%d', $xref_offset);
+    $this->writeLine('%s', '%%EOF');
+  }
+
+}