Improve input processing for ImageMagick and Ghostscript

DEVSIX-5638

Author: ars18wrw

io/src/main/java/com/itextpdf/io/util/FileUtil.java

@@ -43,18 +43,14 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.io.util;
 
-import java.io.InputStream;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import org.slf4j.LoggerFactory;
-
 import java.io.BufferedOutputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileFilter;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
@@ -63,11 +59,15 @@ This file is part of the iText (R) project.
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.List;
+import org.slf4j.LoggerFactory;
 
 /**
  * This file is a helper class for internal usage only.
@@ -223,6 +223,86 @@ public static String parentDirectory(URL url) throws URISyntaxException {
             return url.toURI().resolve(".").toString();
     }
 
+    /**
+     * Creates a temporary file.
+     *
+     * @param tempFilePrefix the prefix of the copied file's name
+     * @param tempFilePostfix the postfix of the copied file's name
+     *
+     * @return the path to the copied file
+     */
+    public static File createTempFile(String tempFilePrefix, String tempFilePostfix) throws IOException {
+        return File.createTempFile(tempFilePrefix, tempFilePostfix);
+    }
+
+    /**
+     * Creates a temporary copy of a file.
+     *
+     * @param file the path to the file to be copied
+     * @param tempFilePrefix the prefix of the copied file's name
+     * @param tempFilePostfix the postfix of the copied file's name
+     *
+     * @return the path to the copied file
+     */
+    public static String createTempCopy(String file, String tempFilePrefix, String tempFilePostfix)
+            throws IOException {
+        Path replacementFilePath = null;
+        try {
+            replacementFilePath = Files.createTempFile(tempFilePrefix, tempFilePostfix);
+            Path pathToPassedFile = Paths.get(file);
+            Files.copy(pathToPassedFile, replacementFilePath, StandardCopyOption.REPLACE_EXISTING);
+        } catch (IOException e) {
+            if (null != replacementFilePath) {
+                FileUtil.removeFiles(new String[] {replacementFilePath.toString()});
+            }
+            throw e;
+        }
+        return replacementFilePath.toString();
+    }
+
+    /**
+     * Creates a copy of a file.
+     *
+     * @param inputFile the path to the file to be copied
+     * @param outputFile the path, to which the passed file should be copied
+     */
+    public static void copy(String inputFile, String outputFile)
+            throws IOException {
+        Files.copy(Paths.get(inputFile), Paths.get(outputFile), StandardCopyOption.REPLACE_EXISTING);
+    }
+
+    /**
+     * Creates a temporary directory.
+     *
+     * @param tempFilePrefix the prefix of the temporary directory's name
+     * @return the path to the temporary directory
+     */
+    public static String createTempDirectory(String tempFilePrefix)
+            throws IOException {
+        return Files.createTempDirectory(tempFilePrefix).toString();
+    }
+
+    /**
+     * Removes all of the passed files.
+     *
+     * @param paths paths to files, which should be removed
+     *
+     * @return true if all the files have been successfully removed, false otherwise
+     */
+    public static boolean removeFiles(String[] paths) {
+        boolean allFilesAreRemoved = true;
+        for (String path : paths) {
+            try {
+                if (null != path) {
+                    Files.delete(Paths.get(path));
+                }
+            } catch (Exception e) {
+                allFilesAreRemoved = false;
+            }
+        }
+        return allFilesAreRemoved;
+    }
+
     private static class CaseSensitiveFileComparator implements Comparator<File> {
         @Override
         public int compare(File f1, File f2) {

io/src/main/java/com/itextpdf/io/util/GhostscriptHelper.java

@@ -46,6 +46,8 @@ This file is part of the iText (R) project.
 import com.itextpdf.io.IoExceptionMessage;
 
 import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.regex.Pattern;
 
 /**
  * A utility class that is used as an interface to run 3rd-party tool Ghostscript.
@@ -67,8 +69,14 @@ public class GhostscriptHelper {
     static final String GHOSTSCRIPT_ENVIRONMENT_VARIABLE_LEGACY = "gsExec";
 
     static final String GHOSTSCRIPT_KEYWORD = "GPL Ghostscript";
+    private static final String TEMP_FILE_PREFIX = "itext_gs_io_temp";
 
-    private static final String GHOSTSCRIPT_PARAMS = " -dSAFER -dNOPAUSE -dBATCH -sDEVICE=png16m -r150 {0} -sOutputFile=\"{1}\" \"{2}\"";
+    private static final String RENDERED_IMAGE_EXTENSION = "png";
+    private static final String GHOSTSCRIPT_PARAMS = " -dSAFER -dNOPAUSE -dBATCH -sDEVICE="
+            + RENDERED_IMAGE_EXTENSION + "16m -r150 {0} -sOutputFile=\"{1}\" \"{2}\"";
+    private static final String PAGE_NUMBER_PATTERN = "%03d";
+
+    private static final Pattern PAGE_LIST_REGEX = Pattern.compile("^(\\d+,)*\\d+$");
 
     private String gsExec;
 
@@ -112,11 +120,17 @@ public String getCliExecutionCommand() {
     }
 
     /**
-     * Runs ghostscript to create images of pdfs.
+     * Runs Ghostscript to render the PDF's pages as PNG images.
      *
-     * @param pdf    Path to the pdf file.
-     * @param outDir Path to the output directory
-     * @param image  Path to the generated image
+     * @param pdf    Path to the PDF file to be rendered
+     * @param outDir Path to the output directory, in which the rendered pages will be stored
+     * @param image  String which defines the name of the resultant images. This string will be
+     *               concatenated with the number of the rendered page from the start of the
+     *               PDF in "-%03d" format, e.g. "-011" for the eleventh rendered page and so on.
+     *               This number may not correspond to the actual page number: for example,
+     *               if the passed pageList equals to "5,3", then images with postfixes "-001.png"
+     *               and "-002.png" will be created: the former for the third page, the latter
+     *               for the fifth page. "%" sign in the passed name is prohibited.
      *
      * @throws IOException          if there are file's reading/writing issues
      * @throws InterruptedException if there is thread interruption while executing GhostScript.
@@ -127,14 +141,20 @@ public void runGhostScriptImageGeneration(String pdf, String outDir, String imag
     }
 
     /**
-     * Runs ghostscript to create images of specified pages of pdfs.
+     * Runs Ghostscript to render the PDF's pages as PNG images.
      *
-     * @param pdf      Path to the pdf file.
-     * @param outDir   Path to the output directory
-     * @param image    Path to the generated image
-     * @param pageList String with numbers of the required pages to extract as image. Should be formatted as string with
-     *                 numbers, separated by commas, without whitespaces. Can be null, if it is required to extract
-     *                 all pages as images.
+     * @param pdf    Path to the PDF file to be rendered
+     * @param outDir Path to the output directory, in which the rendered pages will be stored
+     * @param image  String which defines the name of the resultant images. This string will be
+     *               concatenated with the number of the rendered page from the start of the
+     *               PDF in "-%03d" format, e.g. "-011" for the eleventh rendered page and so on.
+     *               This number may not correspond to the actual page number: for example,
+     *               if the passed pageList equals to "5,3", then images with postfixes "-001.png"
+     *               and "-002.png" will be created: the former for the third page, the latter
+     *               for the fifth page. "%" sign in the passed name is prohibited.
+     * @param pageList String with numbers of the required pages to be rendered as images.
+     *                 This string should be formatted as a string with numbers, separated by commas,
+     *                 without whitespaces. Can be null, if it is required to render all the PDF's pages.
      *
      * @throws IOException          if there are file's reading/writing issues
      * @throws InterruptedException if there is thread interruption while executing GhostScript.
@@ -145,12 +165,48 @@ public void runGhostScriptImageGeneration(String pdf, String outDir, String imag
             throw new IllegalArgumentException(
                     IoExceptionMessage.CANNOT_OPEN_OUTPUT_DIRECTORY.replace("<filename>", pdf));
         }
+        if (!validateImageFilePattern(image)) {
+            throw new IllegalArgumentException("Invalid output image pattern: " + image);
+        }
+        if (!validatePageList(pageList)) {
+            throw new IllegalArgumentException("Invalid page list: " + pageList);
+        }
+        String formattedPageList = (pageList == null) ? "" : "-sPageList=<pagelist>".replace("<pagelist>", pageList);
+
+        String replacementPdf = null;
+        String replacementImagesDirectory = null;
+        String[] temporaryOutputImages = null;
+        try {
+            replacementPdf = FileUtil.createTempCopy(pdf, TEMP_FILE_PREFIX, null);
+            replacementImagesDirectory = FileUtil.createTempDirectory(TEMP_FILE_PREFIX);
+            String currGsParams = MessageFormatUtil.format(GHOSTSCRIPT_PARAMS, formattedPageList,
+                    Paths.get(replacementImagesDirectory,
+                            TEMP_FILE_PREFIX + PAGE_NUMBER_PATTERN + "." + RENDERED_IMAGE_EXTENSION).toString(),
+                    replacementPdf);
+
+            if (!SystemUtil.runProcessAndWait(gsExec, currGsParams)) {
+                temporaryOutputImages = FileUtil
+                        .listFilesInDirectory(replacementImagesDirectory, false);
+                throw new GhostscriptExecutionException(
+                        IoExceptionMessage.GHOSTSCRIPT_FAILED.replace("<filename>", pdf));
+            }
 
-        pageList = (pageList == null) ? "" : "-sPageList=<pagelist>".replace("<pagelist>", pageList);
-
-        String currGsParams = MessageFormatUtil.format(GHOSTSCRIPT_PARAMS, pageList, outDir + image, pdf);
-        if (!SystemUtil.runProcessAndWait(gsExec, currGsParams)) {
-            throw new GhostscriptExecutionException(IoExceptionMessage.GHOSTSCRIPT_FAILED.replace("<filename>", pdf));
+            temporaryOutputImages = FileUtil
+                    .listFilesInDirectory(replacementImagesDirectory, false);
+            if (null != temporaryOutputImages) {
+                for (int i = 0; i < temporaryOutputImages.length; i++) {
+                    FileUtil.copy(temporaryOutputImages[i],
+                            Paths.get(
+                                    outDir,
+                                    image + "-" + formatImageNumber(i + 1) + "." + RENDERED_IMAGE_EXTENSION
+                            ).toString());
+                }
+            }
+        } finally {
+            if (null != temporaryOutputImages) {
+                FileUtil.removeFiles(temporaryOutputImages);
+            }
+            FileUtil.removeFiles(new String[] {replacementImagesDirectory, replacementPdf});
         }
     }
 
@@ -168,4 +224,26 @@ public GhostscriptExecutionException(String msg) {
             super(msg);
         }
     }
+
+    static boolean validatePageList(String pageList) {
+        return null == pageList
+                || PAGE_LIST_REGEX.matcher(pageList).matches();
+    }
+
+    static boolean validateImageFilePattern(String imageFilePattern) {
+        return null != imageFilePattern
+                && !imageFilePattern.trim().isEmpty()
+                && !imageFilePattern.contains("%");
+    }
+
+    static String formatImageNumber(int pageNumber) {
+        StringBuilder stringBuilder = new StringBuilder();
+        int zeroFiller = pageNumber;
+        while (0 == zeroFiller / 100) {
+            stringBuilder.append('0');
+            zeroFiller *= 10;
+        }
+        stringBuilder.append(pageNumber);
+        return stringBuilder.toString();
+    }
 }

io/src/main/java/com/itextpdf/io/util/ImageMagickHelper.java

@@ -45,6 +45,7 @@ This file is part of the iText (R) project.
 
 import com.itextpdf.io.IoExceptionMessage;
 
+import java.io.File;
 import java.io.IOException;
 
 /**
@@ -67,6 +68,8 @@ public class ImageMagickHelper {
 
     static final String MAGICK_COMPARE_KEYWORD = "ImageMagick Studio LLC";
 
+    private static final String TEMP_FILE_PREFIX = "itext_im_io_temp";
+
     private String compareExec;
 
     /**
@@ -113,9 +116,7 @@ public String getCliExecutionCommand() {
      * @param outImageFilePath Path to the output image file
      * @param cmpImageFilePath Path to the cmp image file
      * @param diffImageName    Path to the difference output image file
-     *
      * @return boolean result of comparing: true - images are visually equal
-     *
      * @throws IOException          if there are file's reading/writing issues
      * @throws InterruptedException if there is thread interruption while executing ImageMagick.
      */
@@ -132,22 +133,51 @@ public boolean runImageMagickImageCompare(String outImageFilePath, String cmpIma
      * @param diffImageName    Path to the difference output image file
      * @param fuzzValue        String fuzziness value to compare images. Should be formatted as string with integer
      *                         or decimal number. Can be null, if it is not required to use fuzziness
-     *
      * @return boolean result of comparing: true - images are visually equal
-     *
      * @throws IOException          if there are file's reading/writing issues
      * @throws InterruptedException if there is thread interruption while executing ImageMagick.
      */
     public boolean runImageMagickImageCompare(String outImageFilePath, String cmpImageFilePath,
             String diffImageName, String fuzzValue) throws IOException, InterruptedException {
+        if (!validateFuzziness(fuzzValue)) {
+            throw new IllegalArgumentException("Invalid fuzziness value: " + fuzzValue);
+        }
         fuzzValue = (fuzzValue == null) ? "" : " -metric AE -fuzz <fuzzValue>%".replace("<fuzzValue>", fuzzValue);
 
-        StringBuilder currCompareParams = new StringBuilder();
-        currCompareParams
-                .append(fuzzValue).append(" '")
-                .append(outImageFilePath).append("' '")
-                .append(cmpImageFilePath).append("' '")
-                .append(diffImageName).append("'");
-        return SystemUtil.runProcessAndWait(compareExec, currCompareParams.toString());
+        String replacementOutFile = null;
+        String replacementCmpFile = null;
+        String replacementDiff = null;
+        try {
+            replacementOutFile = FileUtil.createTempCopy(outImageFilePath, TEMP_FILE_PREFIX, null);
+            replacementCmpFile = FileUtil.createTempCopy(cmpImageFilePath, TEMP_FILE_PREFIX, null);
+
+            replacementDiff = FileUtil.createTempFile(TEMP_FILE_PREFIX, null).toString();
+            String currCompareParams = fuzzValue + " '"
+                    + replacementOutFile + "' '"
+                    + replacementCmpFile + "' '"
+                    + replacementDiff + "'";
+            boolean result = SystemUtil.runProcessAndWait(compareExec, currCompareParams);
+
+            if (FileUtil.fileExists(replacementDiff)) {
+                FileUtil.copy(replacementDiff, diffImageName);
+            }
+            return result;
+        } finally {
+            FileUtil.removeFiles(new String[] {replacementOutFile, replacementCmpFile, replacementDiff});
+        }
+    }
+
+    static boolean validateFuzziness(String fuzziness) {
+        if (null == fuzziness) {
+            return true;
+        } else {
+            try {
+                return Double.parseDouble(fuzziness) >= 0;
+            } catch (NumberFormatException e) {
+                // In case of an exception the string could not be parsed to double,
+                // therefore it is considered to be invalid.
+                return false;
+            }
+        }
     }
 }