Update FileTypeDetector API

Core/src/org/sleuthkit/autopsy/modules/filetypeid/FileTypeDetector.java

@@ -179,39 +179,12 @@ public class FileTypeDetector {
      *
      * @param file The file to test.
      *
-     * @return A MIME type name. If file type could not be detected or results
+     * @return A MIME type name. If file type could not be detected, or results
      *         were uncertain, octet-stream is returned.
-     *
-     * @throws TskCoreException if there is a problem writing the result to the
-     *                          case database.
      */
-    public String detect(AbstractFile file) throws TskCoreException {
+    public String detectMIMEType(AbstractFile file) {
-        return detect(file, false);
-    }
-
-    /**
-     * Detects the MIME type of a file. The result is saved to the case database
-     * only if the add to case database flag is set.
-     *
-     * Ingest modules should not set addToCaseDb to true - the ingest process
-     * handles the database save.
-     *
-     * @param file        The file to test.
-     * @param addToCaseDb Whether the MIME type should be added to the case
-     *                    database. This flag is part of a partial workaround
-     *                    for a check-then-act-race condition (see notes in
-     *                    comments for details).
-     *
-     * @return A MIME type name. If file type could not be detected or results
-     *         were uncertain, octet-stream is returned.
-     *
-     * @throws TskCoreException If there is a problem writing the result to the
-     *                          case database.
-     */
-    private String detect(AbstractFile file, boolean addToCaseDb) throws TskCoreException {
         /*
-         * Check to see if the file has already been typed. This is the "check"
+         * Check to see if the file has already been typed.
-         * part of a check-then-act race condition (see note below).
          */
         String mimeType = file.getMIMEType();
         if (null != mimeType) {
@@ -281,31 +254,6 @@ public class FileTypeDetector {
             }
         }
 
-        /*
-         * If adding the result to the case database, do so now.
-         *
-         * NOTE: This condtional is a way to deal with the check-then-act race
-         * condition created by the gap between querying the MIME type and
-         * recording it. It is not really a problem for the mime_type column of
-         * the tsk_files table, but it can lead to duplicate blackboard posts,
-         * and the posts are required to maintain backward compatibility.
-         * Various mitigation strategies were considered. It was decided to go
-         * with the policy that only ingest modules are allowed to add file
-         * types to the case database, at least until such time as file types
-         * are no longer posted to the blackboard. Of course, this is not a
-         * perfect solution. It's not really enforceable for community
-         * contributed plug ins and it does not handle the unlikely but possible
-         * scenario of multiple processes typing the same file for a multi-user
-         * case.
-         */
-        if (addToCaseDb) {
-            /*
-             * Add the MIME type to the files table in the case database.
-             */
-            Case.getCurrentCase().getSleuthkitCase().setFileMIMEType(file, mimeType);
-        }
-
-        file.setMIMEType(mimeType);
         return mimeType;
     }
 
@@ -327,7 +275,9 @@ public class FileTypeDetector {
 
     /**
      * Determines whether or not the a file matches a user-defined custom file
-     * type.
+     * type. If the file matches and corresponds to an interesting files type
+     * rule, this method has the side effect of creating an interesting files
+     * hit artifact and indexing that artifact for keyword search.
      *
      * @param file The file to test.
      *
@@ -335,10 +285,11 @@ public class FileTypeDetector {
      *
      * @throws TskCoreException
      */
-    private String detectUserDefinedType(AbstractFile file) throws TskCoreException {
+    private String detectUserDefinedType(AbstractFile file) {
         for (FileType fileType : userDefinedFileTypes) {
             if (fileType.matches(file)) {
                 if (fileType.createInterestingFileHit()) {
+                    try {
                         BlackboardArtifact artifact;
                         artifact = file.newArtifact(BlackboardArtifact.ARTIFACT_TYPE.TSK_INTERESTING_FILE_HIT);
                         Collection<BlackboardAttribute> attributes = new ArrayList<>();
@@ -346,23 +297,24 @@ public class FileTypeDetector {
                         attributes.add(setNameAttribute);
 
                         /*
-                     * Use the MIME type as the category attribute, i.e., the
+                         * Use the MIME type as the category attribute, i.e.,
-                     * rule that determined this file belongs to the interesting
+                         * the rule that determined this file belongs to the
-                     * files set.
+                         * interesting files set.
                          */
                         BlackboardAttribute ruleNameAttribute = new BlackboardAttribute(BlackboardAttribute.ATTRIBUTE_TYPE.TSK_CATEGORY, FileTypeIdModuleFactory.getModuleName(), fileType.getMimeType());
                         attributes.add(ruleNameAttribute);
 
                         artifact.addAttributes(attributes);
+                        try {
                             /*
                              * Index the artifact for keyword search.
                              */
-                    try {
                             Case.getCurrentCase().getServices().getBlackboard().indexArtifact(artifact);
                         } catch (Blackboard.BlackboardException ex) {
-                        logger.log(Level.SEVERE, String.format("Unable to index blackboard artifact %d", artifact.getArtifactID()), ex); //NON-NLS
+                            logger.log(Level.SEVERE, String.format("Unable to index TSK_INTERESTING_FILE_HIT blackboard artifact %d (file obj_id=%d)", artifact.getArtifactID(), file.getId()), ex); //NON-NLS
-                        MessageNotifyUtil.Notify.error(
+                        }
-                                NbBundle.getMessage(Blackboard.class, "Blackboard.unableToIndexArtifact.exception.msg"), artifact.getDisplayName());
+                    } catch (TskCoreException ex) {
+                        logger.log(Level.SEVERE, String.format("Unable to create TSK_INTERESTING_FILE_HIT artifact for file (obj_id=%d)", file.getId()), ex); //NON-NLS
                     }
                 }
 
@@ -379,10 +331,8 @@ public class FileTypeDetector {
      * @param file The file to test.
      *
      * @return The file type name string or null, if no match is detected.
-     *
-     * @throws TskCoreException
      */
-    private String detectAutopsyDefinedType(AbstractFile file) throws TskCoreException {
+    private String detectAutopsyDefinedType(AbstractFile file) {
         for (FileType fileType : autopsyDefinedFileTypes) {
             if (fileType.matches(file)) {
                 return fileType.getMimeType();
@@ -452,12 +402,16 @@ public class FileTypeDetector {
      *
      * @throws TskCoreException if detection is required and there is a problem
      *                          writing the result to the case database.
-     * @deprecated Use getFileType instead and use AbstractFile.getMIMEType
+     * @deprecated Use detectMIMEType instead, and call AbstractFile.setMIMEType
-     * instead of querying the blackboard.
+     * and AbstractFile.save to save the result to the file object and the
+     * database.
      */
     @Deprecated
     public String detectAndPostToBlackboard(AbstractFile file) throws TskCoreException {
-        return detect(file, true);
+        String fileType = detectMIMEType(file);
+        file.setMIMEType(fileType);
+        file.save();
+        return fileType;
     }
 
     /**
@@ -472,11 +426,35 @@ public class FileTypeDetector {
      * @throws TskCoreException if detection is required and there is a problem
      *                          writing the result to the case database.
      *
-     * @deprecated
+     * @deprecated Use detectMIMEType instead, and call AbstractFile.setMIMEType
+     * and AbstractFile.save to save the result to the file object and the
+     * database.
      */
     @Deprecated
     public String getFileType(AbstractFile file) throws TskCoreException {
-        return detect(file, true);
+        String fileType = detectMIMEType(file);
+        file.setMIMEType(fileType);
+        file.save();
+        return fileType;
+    }
+
+    /**
+     * Detects the MIME type of a file. The result is not added to the case
+     * database.
+     *
+     * @param file The file to test.
+     *
+     * @return A MIME type name. If file type could not be detected or results
+     *         were uncertain, octet-stream is returned.
+     *
+     * @throws TskCoreException
+     * @deprecated Use detectMIMEType instead.
+     */
+    @Deprecated
+    public String detect(AbstractFile file) throws TskCoreException {
+        String fileType = detectMIMEType(file);
+        file.setMIMEType(fileType); // Retain side effect of setting value in file object.
+        return fileType;
     }
 
 }