Add possibility to return the number of different pixels in ImageMagickHelper class

DEVSIX-5870

Author: EvgenyB1001

commons/src/main/java/com/itextpdf/commons/utils/ProcessInfo.java

@@ -0,0 +1,52 @@
+package com.itextpdf.commons.utils;
+
+/**
+ * Class contains a process information, such as process exit code and process output.
+ */
+public final class ProcessInfo {
+
+    private final int exitCode;
+    private final String processStdOutput;
+    private final String processErrOutput;
+
+    /**
+     * Create a new instance, containing a process information,
+     * such as process exit code, process standard and error outputs.
+     *
+     * @param exitCode      exit code of the process.
+     * @param processStdOutput the standard output of the process.
+     * @param processErrOutput the error output of the process.
+     */
+    public ProcessInfo(int exitCode, String processStdOutput, String processErrOutput) {
+        this.exitCode = exitCode;
+        this.processStdOutput = processStdOutput;
+        this.processErrOutput = processErrOutput;
+    }
+
+    /**
+     * Getter for a process exit code.
+     *
+     * @return Returns a process exit code.
+     */
+    public int getExitCode() {
+        return exitCode;
+    }
+
+    /**
+     * Getter for a standard process output.
+     *
+     * @return Returns a process standard output string.
+     */
+    public String getProcessStdOutput() {
+        return processStdOutput;
+    }
+
+    /**
+     * Getter for an error process output.
+     *
+     * @return Returns a process error output string.
+     */
+    public String getProcessErrOutput() {
+        return processErrOutput;
+    }
+}

commons/src/main/java/com/itextpdf/commons/utils/SystemUtil.java

@@ -45,6 +45,7 @@ This file is part of the iText (R) project.
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -130,6 +131,14 @@ public static StringBuilder runProcessAndCollectErrors(String execPath, String p
         return printProcessErrorsOutput(runProcess(execPath, params, null));
     }
 
+    public static ProcessInfo runProcessAndGetProcessInfo(String command, String params) throws IOException,
+            InterruptedException {
+        Process p = runProcess(command, params, null);
+        String processStdOutput = printProcessStandardOutput(p).toString();
+        String processErrOutput = printProcessErrorsOutput(p).toString();
+        return new ProcessInfo(p.waitFor(), processStdOutput, processErrOutput);
+    }
+
     static Process runProcess(String execPath, String params, String workingDirPath) throws IOException {
         List<String> cmdList = prepareProcessArguments(execPath, params);
         String[] cmdArray = cmdList.toArray(new String[0]);
@@ -181,8 +190,16 @@ static String getProcessOutput(Process p) throws IOException {
     }
 
     static StringBuilder printProcessErrorsOutput(Process p) throws IOException {
+        return printProcessOutput(p.getErrorStream());
+    }
+
+    static StringBuilder printProcessStandardOutput(Process p) throws IOException {
+        return printProcessOutput(p.getInputStream());
+    }
+
+    private static StringBuilder printProcessOutput(InputStream processStream) throws IOException {
         StringBuilder builder = new StringBuilder();
-        BufferedReader bre = new BufferedReader(new InputStreamReader(p.getErrorStream()));
+        BufferedReader bre = new BufferedReader(new InputStreamReader(processStream));
         String line;
         while ((line = bre.readLine()) != null) {
             System.out.println(line);

commons/src/test/java/com/itextpdf/commons/utils/ProcessInfoTest.java

@@ -0,0 +1,36 @@
+package com.itextpdf.commons.utils;
+
+import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.test.annotations.type.UnitTest;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category(UnitTest.class)
+public class ProcessInfoTest extends ExtendedITextTest {
+
+    @Test
+    public void getExitCodeTest() {
+        int exitCode = 1;
+        ProcessInfo processInfo = new ProcessInfo(exitCode, null,  null);
+
+        Assert.assertEquals(exitCode, processInfo.getExitCode());
+    }
+
+    @Test
+    public void getProcessStdOutput() {
+        String stdOutput = "output";
+        ProcessInfo processInfo = new ProcessInfo(0, stdOutput,  null);
+
+        Assert.assertEquals(stdOutput, processInfo.getProcessStdOutput());
+    }
+
+    @Test
+    public void getProcessErrOutput() {
+        String stdOutput = "output";
+        ProcessInfo processInfo = new ProcessInfo(0, null,  stdOutput);
+
+        Assert.assertEquals(stdOutput, processInfo.getProcessErrOutput());
+    }
+}

commons/src/test/java/com/itextpdf/commons/utils/SystemUtilTest.java

@@ -165,6 +165,19 @@ public void runProcessAndWaitWithWorkingDirectoryTest() throws IOException, Inte
         Assert.assertTrue(FileUtil.fileExists(diff));
     }
 
+    @Test
+    public void runProcessAndGetProcessInfoTest() throws IOException, InterruptedException {
+        String imageMagickPath = SystemUtil.getPropertyOrEnvironmentVariable(MAGICK_COMPARE_ENVIRONMENT_VARIABLE);
+        if (imageMagickPath == null) {
+            imageMagickPath = SystemUtil.getPropertyOrEnvironmentVariable(MAGICK_COMPARE_ENVIRONMENT_VARIABLE_LEGACY);
+        }
+
+        ProcessInfo processInfo = SystemUtil.runProcessAndGetProcessInfo(imageMagickPath,"--version");
+
+        Assert.assertNotNull(processInfo);
+        Assert.assertEquals(0, processInfo.getExitCode());
+    }
+
 
     static class TestProcess extends Process {
 

io/src/main/java/com/itextpdf/io/exceptions/IoExceptionMessage.java

@@ -63,5 +63,7 @@ public final class IoExceptionMessage {
                     + " environment variable to a CLI command that can run the Ghostscript application. See BUILDING.MD in the root of the repository for more details.";
     public static final String GHOSTSCRIPT_FAILED = "GhostScript failed for <filename>";
     public static final String CANNOT_OPEN_OUTPUT_DIRECTORY = "Cannot open output directory for <filename>";
-
+    public static final String IMAGE_MAGICK_OUTPUT_IS_NULL = "ImageMagick process output is null.";
+    public static final String IMAGE_MAGICK_PROCESS_EXECUTION_FAILED =
+            "ImageMagick process execution finished with errors: ";
 }

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

@@ -0,0 +1,40 @@
+package com.itextpdf.io.util;
+
+/**
+ * A helper data class, which aggregates true/false result of ImageMagick comparing
+ * as well as the number of different pixels.
+ */
+public final class ImageMagickCompareResult {
+
+    private final boolean result;
+    private final long diffPixels;
+
+    /**
+     * Creates an instance that contains ImageMagick comparing result information.
+     *
+     * @param result     true, if the compared images are equal.
+     * @param diffPixels number of different pixels.
+     */
+    public ImageMagickCompareResult(boolean result, long diffPixels) {
+        this.result = result;
+        this.diffPixels = diffPixels;
+    }
+
+    /**
+     * Returns image compare boolean value.
+     *
+     * @return true if the compared images are equal.
+     */
+    public boolean isComparingResultSuccessful() {
+        return result;
+    }
+
+    /**
+     * Getter for a different pixels count.
+     *
+     * @return Returns a a different pixels count.
+     */
+    public long getDiffPixels() {
+        return diffPixels;
+    }
+}

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

@@ -44,11 +44,13 @@ This file is part of the iText (R) project.
 package com.itextpdf.io.util;
 
 import com.itextpdf.commons.utils.FileUtil;
+import com.itextpdf.commons.utils.ProcessInfo;
 import com.itextpdf.commons.utils.SystemUtil;
 import com.itextpdf.io.exceptions.IoExceptionMessage;
 
-import java.io.File;
 import java.io.IOException;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * A utility class that is used as an interface to run 3rd-party tool ImageMagick.
@@ -71,6 +73,9 @@ public class ImageMagickHelper {
     static final String MAGICK_COMPARE_KEYWORD = "ImageMagick Studio LLC";
 
     private static final String TEMP_FILE_PREFIX = "itext_im_io_temp";
+    private static final String DIFF_PIXELS_OUTPUT_REGEXP = "^\\d+\\.*\\d*(e\\+\\d+)?";
+
+    private static final Pattern pattern = Pattern.compile(DIFF_PIXELS_OUTPUT_REGEXP);
 
     private String compareExec;
 
@@ -141,6 +146,58 @@ public boolean runImageMagickImageCompare(String outImageFilePath, String cmpIma
      */
     public boolean runImageMagickImageCompare(String outImageFilePath, String cmpImageFilePath,
             String diffImageName, String fuzzValue) throws IOException, InterruptedException {
+        ImageMagickCompareResult compareResult = runImageMagickImageCompareAndGetResult(outImageFilePath,
+                cmpImageFilePath, diffImageName, fuzzValue);
+
+        return compareResult.isComparingResultSuccessful();
+    }
+
+    /**
+     * Runs imageMagick to visually compare images with the specified fuzziness value and given threshold
+     * and generate difference output.
+     *
+     * @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
+     * @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
+     * @param threshold        Long value of accepted threshold.
+     *
+     * @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 runImageMagickImageCompareWithThreshold(String outImageFilePath, String cmpImageFilePath,
+            String diffImageName, String fuzzValue, long threshold) throws IOException, InterruptedException {
+        ImageMagickCompareResult compareResult = runImageMagickImageCompareAndGetResult(outImageFilePath,
+                cmpImageFilePath, diffImageName, fuzzValue);
+
+        if (compareResult.isComparingResultSuccessful()) {
+            return true;
+        } else {
+            return compareResult.getDiffPixels() <= threshold;
+        }
+    }
+
+    /**
+     * Runs imageMagick to visually compare images with the specified fuzziness value and generate difference output.
+     * This method returns an object of {@link ImageMagickCompareResult}, containing comparing result information,
+     * such as boolean result value and the number of different pixels.
+     *
+     * @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
+     * @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 an object of {@link ImageMagickCompareResult}. containing comparing result information.
+     *
+     * @throws IOException          if there are file's reading/writing issues
+     * @throws InterruptedException if there is thread interruption while executing ImageMagick.
+     */
+    public ImageMagickCompareResult runImageMagickImageCompareAndGetResult(String outImageFilePath,
+            String cmpImageFilePath, String diffImageName, String fuzzValue) throws IOException, InterruptedException {
         if (!validateFuzziness(fuzzValue)) {
             throw new IllegalArgumentException("Invalid fuzziness value: " + fuzzValue);
         }
@@ -160,12 +217,15 @@ public boolean runImageMagickImageCompare(String outImageFilePath, String cmpIma
                     + replacementOutFile + "' '"
                     + replacementCmpFile + "' '"
                     + replacementDiff + "'";
-            boolean result = SystemUtil.runProcessAndWait(compareExec, currCompareParams);
+            ProcessInfo processInfo = SystemUtil.runProcessAndGetProcessInfo(compareExec, currCompareParams);
+            boolean comparingResult = processInfo.getExitCode() == 0;
+            long diffPixels = parseImageMagickProcessOutput(processInfo.getProcessErrOutput());
+            ImageMagickCompareResult resultInfo = new ImageMagickCompareResult(comparingResult, diffPixels);
 
             if (FileUtil.fileExists(replacementDiff)) {
                 FileUtil.copy(replacementDiff, diffImageName);
             }
-            return result;
+            return resultInfo;
         } finally {
             FileUtil.removeFiles(new String[] {replacementOutFile, replacementCmpFile, replacementDiff});
         }
@@ -184,4 +244,29 @@ static boolean validateFuzziness(String fuzziness) {
             }
         }
     }
+
+    private static long parseImageMagickProcessOutput(String processOutput) throws IOException {
+        if (null == processOutput) {
+            throw new IllegalArgumentException(IoExceptionMessage.IMAGE_MAGICK_OUTPUT_IS_NULL);
+        }
+
+        if (processOutput.isEmpty()) {
+            return 0L;
+        }
+
+        String[] processOutputLines = processOutput.split("\n");
+
+        for (String line : processOutputLines) {
+            try {
+                Matcher matcher = pattern.matcher(line);
+                if (matcher.find()) {
+                    return (long) Double.valueOf(matcher.group()).longValue();
+                }
+            } catch (NumberFormatException e) {
+                // Nothing should be done here because of the exception, that will be thrown later.
+            }
+        }
+
+        throw new IOException(IoExceptionMessage.IMAGE_MAGICK_PROCESS_EXECUTION_FAILED + processOutput);
+    }
 }