Fix the text format guesser so it doesn't inappropriately guess WikiText (#2924)

* Fix text guesser so it doesn't guess wikitext

Fixes #2850
- Add simple magic detector for zip & gzip files to keep
  it from attempting to guess binary files
- Add a counter for C0 controls for the same reason
- Tighten wikitable counters to require marker at
  beginning of the line, per the specification
- Refactor to use Apache Commons instead of private
  counting methods
- Add tests for most TextGuesser formats

* Remove misplaced duplicate test data file

* Fix LGTM warning + minor cleanups

* Use BoundedInputStream to prevent runaway lines

main/src/com/google/refine/importers/TextFormatGuesser.java

@@ -26,66 +26,92 @@
  ******************************************************************************/
 package com.google.refine.importers;
 
+import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.io.Reader;
 import java.io.UnsupportedEncodingException;
+import java.util.Arrays;
 
+import org.apache.commons.io.input.BoundedInputStream;
+import org.apache.commons.lang.StringUtils;
+
+import com.google.common.base.CharMatcher;
 import com.google.refine.importing.FormatGuesser;
 
 public class TextFormatGuesser implements FormatGuesser {
 
+    private static final int XML_BRACKETS_THRESHOLD = 5;
+    private static final int JSON_BRACES_THRESHOLD = 5;
+    private static final long CONTROLS_THRESHOLD = 10;
+
     @Override
     public String guess(File file, String encoding, String seedFormat) {
-        try {
-            InputStream is = new FileInputStream(file);
-            Reader reader = encoding != null ? new InputStreamReader(is, encoding) : new InputStreamReader(is);
+        try(InputStream fis = new FileInputStream(file)) {
+            if (isCompressed(file)) {
+                return "binary";
+            };
 
-            try {
-                int totalBytes = 0;
-                int openBraces = 0;
+            InputStream bis = new BoundedInputStream(fis, 64 * 1024); // TODO: This seems like a lot
+            try (BufferedReader reader = new BufferedReader(
+                    encoding != null ? new InputStreamReader(bis, encoding) : new InputStreamReader(bis))) {
+                int totalChars = 0;
+                long openBraces = 0;
                 int closeBraces = 0;
                 int openAngleBrackets = 0;
                 int closeAngleBrackets = 0;
                 int wikiTableBegin = 0;
+                int wikiTableEnd = 0;
                 int wikiTableRow = 0;
                 int trailingPeriods = 0;
-                
+                int controls = 0;
+
                 char firstChar = ' ';
                 boolean foundFirstChar = false;
-                
-                char[] chars = new char[4096];
-                int c;
-                while (totalBytes < 64 * 1024 && (c = reader.read(chars)) > 0) {
-                    String chunk = String.valueOf(chars, 0, c);
-                    openBraces += countSubstrings(chunk, "{");
-                    closeBraces += countSubstrings(chunk, "}");
-                    openAngleBrackets += countSubstrings(chunk, "<");
-                    closeAngleBrackets += countSubstrings(chunk, ">");
-                    wikiTableBegin += countSubstrings(chunk, "{|");
-                    wikiTableRow += countSubstrings(chunk, "|-");
-                    trailingPeriods += countLineSuffix(chunk, ".");
-                    
+
+                String line;
+                while ((line = reader.readLine()) != null && controls < CONTROLS_THRESHOLD) {
+                    line = line.trim();
+                    controls += CharMatcher.javaIsoControl().countIn(line);
+                    openBraces += line.chars().filter(ch -> ch == '{').count();
+                    closeBraces += StringUtils.countMatches(line, "}");
+                    openAngleBrackets += StringUtils.countMatches(line, "<");
+                    closeAngleBrackets += StringUtils.countMatches(line, ">");
+                    if (line.startsWith("{|")) {
+                        wikiTableBegin++;
+                    } else if (line.startsWith("|}")) {
+                        wikiTableEnd++;
+                    } else if (line.startsWith("|-")) {
+                        wikiTableRow++;
+                    }
+                    if (line.endsWith(".")) {
+                        trailingPeriods++;
+                    }
+
                     if (!foundFirstChar) {
-                        chunk = chunk.trim();
-                        if (chunk.length() > 0) {
-                            firstChar = chunk.charAt(0);
+                        if (line.length() > 0) {
+                            firstChar = line.charAt(0);
                             foundFirstChar = true;
                         }
                     }
-                    totalBytes += c;
+                    totalChars += line.length();
                 }
-                
+
+                // TODO: Make thresholds proportional to the amount of data read?
+                if (controls >= CONTROLS_THRESHOLD) {
+                    return "binary";
+                }
+
                 if (foundFirstChar) {
-                    if (wikiTableBegin >= 1 && wikiTableRow >= 2) {
+                    if (wikiTableBegin >= 1 && (wikiTableBegin - wikiTableEnd <= 1) && wikiTableRow >= 2) {
                         return "text/wiki";
                     } if ((firstChar == '{' || firstChar == '[') &&
-                        openBraces >= 5 && closeBraces >= 5) {
+                        openBraces >= JSON_BRACES_THRESHOLD && closeBraces >= JSON_BRACES_THRESHOLD) {
                         return "text/json";
-                    } else if (openAngleBrackets >= 5 && closeAngleBrackets >= 5) {
+                    } else if (openAngleBrackets >= XML_BRACKETS_THRESHOLD
+                            && closeAngleBrackets >= XML_BRACKETS_THRESHOLD) {
                         if (trailingPeriods > 0) {
                             return "text/rdf/n3";
                         } else if (firstChar == '<') {
@@ -94,9 +120,6 @@ public class TextFormatGuesser implements FormatGuesser {
                     }
                 }
                 return "text/line-based";
-            } finally {
-                reader.close();
-                is.close();
             }
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
@@ -105,46 +128,20 @@ public class TextFormatGuesser implements FormatGuesser {
         }
         return null;
     }
-    
-    static public int countSubstrings(String s, String sub) {
-        int count = 0;
-        int from = 0;
-        while (from < s.length()) {
-            int i = s.indexOf(sub, from);
-            if (i < 0) {
-                break;
-            } else {
-                from = i + sub.length();
-                count++;
+
+    private boolean isCompressed(File file) throws IOException {
+        // Check for common compressed file types to protect ourselves from binary data
+        try(InputStream is = new FileInputStream(file)) {
+            byte[] magic = new byte[4];
+            int count = is.read(magic);
+            if (count == 4 && Arrays.equals(magic, new byte[] {0x50,0x4B, 0x03, 0x04}) || // zip
+                    Arrays.equals(magic, new byte[] {0x50,0x4B, 0x07, 0x08}) ||
+                    (magic[0] == 0x1F && magic[1] == (byte)0x8B) // gzip
+                    ) {
+                return true;
             }
         }
-        return count;
-    }
-    
-    static public int countLineSuffix(String s, String suffix) {
-        int count = 0;
-        int from = 0;
-        while (from < s.length()) {
-            int lineEnd = s.indexOf('\n', from);
-            if (lineEnd < 0) {
-                break;
-            } else {
-                int i = lineEnd - 1;
-                while (i >= from + suffix.length() - 1) {
-                    if (Character.isWhitespace(s.charAt(i))) {
-                        i--;
-                    } else {
-                        String suffix2 = s.subSequence(i - suffix.length() + 1, i + 1).toString();
-                        if (suffix2.equals(suffix)) {
-                            count++;
-                        }
-                        break;
-                    }
-                }
-                from = lineEnd + 1;
-            }
-        }
-        return count;
+        return false;
     }
 
 }

main/tests/server/src/com/google/refine/importers/TextFormatGuesserTests.java

@@ -0,0 +1,269 @@
+/*
+
+Copyright 2020 OpenRefine committers
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+ * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+ * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+ */
+
+package com.google.refine.importers;
+
+
+import static org.testng.Assert.assertEquals;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStreamWriter;
+import java.nio.charset.Charset;
+import java.util.zip.GZIPInputStream;
+
+import org.apache.commons.io.FileUtils;
+import org.slf4j.LoggerFactory;
+import org.testng.annotations.AfterMethod;
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.BeforeTest;
+import org.testng.annotations.Test;
+
+import com.google.common.io.PatternFilenameFilter;
+import com.google.refine.importing.FormatGuesser;
+
+
+public class TextFormatGuesserTests extends ImporterTest {
+
+    FormatGuesser guesser;
+
+    @Override
+    @BeforeTest
+    public void init() {
+        logger = LoggerFactory.getLogger(this.getClass());
+    }
+
+    @Override
+    @BeforeMethod
+    public void setUp() {
+        super.setUp();
+        guesser = new TextFormatGuesser();
+    }
+
+    @Override
+    @AfterMethod
+    public void tearDown(){
+        guesser = null;
+        super.tearDown();
+    }
+
+    @Test
+    public void xlsTextGuessTest() throws FileNotFoundException, IOException {
+        String dir = ClassLoader.getSystemResource("Colorado-Municipalities-small-xlsx.gz").getPath();
+        InputStream is = new GZIPInputStream(new FileInputStream(new File(dir)));
+        File tmp = File.createTempFile("openrefinetests-textguesser", "");
+        FileUtils.copyInputStreamToFile(is, tmp);
+        String format = guesser.guess(tmp, "UTF-8", "text");
+        assertEquals(format, "binary");
+    }
+
+    @Test
+    public void csvGuesserTest() {
+        extensionGuesserTests("csv", "text/line-based");
+    }
+
+    @Test(enabled=false) // FIXME: Our JSON guesser doesn't work on small files
+    public void jsonGuesserTest() {
+        extensionGuesserTests("json", "text/json");
+    }
+
+    @Test
+    public void xmlGuesserTest() {
+        extensionGuesserTests("xml", "text/xml");
+    }
+
+    private void extensionGuesserTests(String extension, String expectedFormat) {
+        String dir = ClassLoader.getSystemResource("food.csv").getPath();
+        dir = dir.substring(0, dir.lastIndexOf('/'));
+        File testDataDir =  new File(dir);
+        for (String testFile : testDataDir.list(new PatternFilenameFilter(".+\\." + extension))) {
+            String format = guesser.guess(new File(dir, testFile), "UTF-8", "text");
+            logger.info(format + " " + testFile);
+            assertEquals(format, expectedFormat);
+        }
+    }
+
+    @Test
+    public void guessWikiTable() throws IOException {
+        String input = "\n"
+                + "{|\n"
+                + "|-\n"
+                + "| a || b<br/>2 || c \n"
+                + "|-\n"
+                + "| d || e || f<br>\n"
+                + "|-\n"
+                + "|}\n";
+        testWikiTableString(input);
+    }
+
+    private void testWikiTableString(String input) throws IOException, FileNotFoundException {
+        File tmp = File.createTempFile("openrefinetests-textguesser", "");
+        OutputStreamWriter writer = new OutputStreamWriter(
+                new FileOutputStream(tmp),
+                Charset.forName("UTF-8").newEncoder()
+                );
+        writer.write(input);
+        writer.close();
+        String format = guesser.guess(tmp, "UTF-8", "text");
+        assertEquals(format, "text/wiki");
+    }
+
+    @Test
+    public void guessTableWithMisplacedHeaders() throws FileNotFoundException, IOException {
+        String input = "\n"
+                + "{|\n"
+                + "|-\n"
+                + "| a || b<br/>2 || c \n"
+                + "|-\n"
+                + "| d\n"
+                + "! e\n"
+                + "| f<br>\n"
+                + "|-\n"
+                + "|}\n";
+        testWikiTableString(input);
+    }
+
+    @Test
+    public void guessTableWithLinks() throws FileNotFoundException, IOException  {
+
+        // Data credits: Wikipedia contributors, https://de.wikipedia.org/w/index.php?title=Agenturen_der_Europäischen_Union&action=edit
+        String input = "\n"
+                +"{|\n"
+                +"|-\n"
+                +"| [[Europäisches Zentrum für die Förderung der Berufsbildung|Cedefop]] || Cedefop || http://www.cedefop.europa.eu/\n"
+                +"|-\n"
+                +"| [[Europäische Stiftung zur Verbesserung der Lebens- und Arbeitsbedingungen]] || EUROFOUND || [http://www.eurofound.europa.eu/]\n"
+                +"|-\n"
+                +"| [[Europäische Beobachtungsstelle für Drogen und Drogensucht]] || EMCDDA || [http://www.emcdda.europa.eu/ europa.eu]\n"
+                +"|-\n"
+                +"|}\n";
+        testWikiTableString(input);
+    }
+
+    @Test
+    public void readStyledTableWithHeader() throws FileNotFoundException, IOException {
+        // Data credits: Wikipedia contributors, https://de.wikipedia.org/w/index.php?title=Agenturen_der_Europäischen_Union&action=edit
+        String input = "\n"
+                +"==Agenturen==\n"
+                +"{| class=\"wikitable sortable\"\n"
+                +"! style=\"text-align:left; width: 60em\" | Offizieller Name\n"
+                +"! style=\"text-align:left; width: 9em\" | Abkürzung\n"
+                +"! style=\"text-align:left; width: 6em\" | Website\n"
+                +"! style=\"text-align:left; width: 15em\" | Standort\n"
+                +"! style=\"text-align:left; width: 18em\" | Staat\n"
+                +"! style=\"text-align:left; width: 6em\" | Gründung\n"
+                +"! style=\"text-align:left; width: 50em\" | Anmerkungen\n"
+                +"|-\n"
+                +"| [[Europäisches Zentrum für die Förderung der Berufsbildung]] || '''Cedefop''' || [http://www.cedefop.europa.eu/] || [[Thessaloniki]] || {{Griechenland}} || 1975 ||\n"
+                +"|-\n"
+                +"| [[Europäische Stiftung zur Verbesserung der Lebens- und Arbeitsbedingungen]] || ''EUROFOUND'' || [http://www.eurofound.europa.eu/] || [[Dublin]] || {{Irland}} || 1975 ||\n"
+                +"|-\n"
+                +"| [[Europäische Beobachtungsstelle für Drogen und Drogensucht]] || EMCDDA || [http://www.emcdda.europa.eu/] || [[Lissabon]] || {{Portugal}} || 1993 ||\n"
+                +"|-\n"
+                +"|}\n";
+        testWikiTableString(input);
+    }
+
+    @Test
+    public void guessTableWithSpanningCells() throws FileNotFoundException, IOException {
+        // inspired from https://www.mediawiki.org/wiki/Help:Tables
+        String input = "{| class=\"wikitable\"\n"
+                +"!colspan=\"6\"|Shopping List\n"
+                +"|-\n"
+                +"|Bread & Butter\n"
+                +"|Pie\n"
+                +"|Buns\n"
+                +"|rowspan=\"2\"|Danish\n"
+                +"|colspan=\"2\"|Croissant\n"
+                +"|-\n"
+                +"|Cheese\n"
+                +"|colspan=\"2\"|Ice cream\n"
+                +"|Butter\n"
+                +"|Yogurt\n"
+                +"|}\n";
+        testWikiTableString(input);
+    }
+
+    @Test
+    public void guessTableWithReferences() throws FileNotFoundException, IOException {
+        // inspired from https://www.mediawiki.org/wiki/Help:Tables
+        String input = "{|\n"
+                +"! price\n"
+                +"! fruit\n"
+                +"! merchant\n"
+                +"|-\n"
+                +"| a || b <ref name=\"myref\"> See [http://gnu.org here]</ref>  || c <ref name=\"ms\"> or http://microsoft.com/ </ref>\n"
+                +"|-\n"
+                +"| d || e <ref name=\"ms\"/>|| f <ref name=\"myref\" />\n"
+                +"|-\n"
+                +"|}\n";
+        testWikiTableString(input);
+    }
+
+    @Test
+    public void guessTableWithReferencesTemplates() throws FileNotFoundException, IOException {
+        // inspired from https://www.mediawiki.org/wiki/Help:Tables
+        String input = "{|\n"
+                +"! price\n"
+                +"! fruit\n"
+                +"! merchant\n"
+                +"|-\n"
+                +"| a || b <ref name=\"myref\">{{cite web|url=http://gnu.org|accessdate=2017-08-30}}</ref>  || c <ref name=\"ms\"> or {{cite journal|url=http://microsoft.com/|title=BLah}} </ref>\n"
+                +"|-\n"
+                +"| d || e <ref name=\"ms\"/>|| f <ref name=\"myref\" />\n"
+                +"|-\n"
+                +"|}\n";
+        testWikiTableString(input);
+    }
+
+
+    @Test
+    public void guessTableWithTemplates() throws FileNotFoundException, IOException {
+        String input = "\n"
+                + "{|\n"
+                + "|-\n"
+                + "| {{free to read}} || b || c \n"
+                + "|-\n"
+                + "| d\n"
+                + "| [[File:My logo.svg|70px]]\n"
+                + "| f<br>\n"
+                + "|-\n"
+                + "|}\n";
+        testWikiTableString(input);
+    }
+
+}