AbstractFile.java

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/*
 * SleuthKit Java Bindings
 *
 * Copyright 2011-2022 Basis Technology Corp.
 * Contact: carrier <at> sleuthkit <dot> org
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.sleuthkit.datamodel;

import com.google.common.annotations.Beta;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.lang.ref.SoftReference;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.ResourceBundle;
import java.util.Set;
import java.util.SortedSet;
import java.util.TimeZone;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.sleuthkit.datamodel.SleuthkitCase.CaseDbTransaction;
import org.sleuthkit.datamodel.TskData.CollectedStatus;
import org.sleuthkit.datamodel.TskData.FileKnown;
import org.sleuthkit.datamodel.TskData.TSK_FS_META_FLAG_ENUM;
import org.sleuthkit.datamodel.TskData.TSK_FS_META_TYPE_ENUM;
import org.sleuthkit.datamodel.TskData.TSK_FS_NAME_FLAG_ENUM;
import org.sleuthkit.datamodel.TskData.TSK_FS_NAME_TYPE_ENUM;

public abstract class AbstractFile extends AbstractContent {

        protected final TskData.TSK_DB_FILES_TYPE_ENUM fileType;
        protected final TSK_FS_NAME_TYPE_ENUM dirType;
        protected final TSK_FS_META_TYPE_ENUM metaType;
        protected TSK_FS_NAME_FLAG_ENUM dirFlag;
        protected Set<TSK_FS_META_FLAG_ENUM> metaFlags;
        protected final Long fileSystemObjectId;  // File system object ID; may be null
        protected long size;
        protected final long metaAddr, ctime, crtime, atime, mtime;
        protected final int metaSeq;
        protected final int uid, gid;
        protected final int attrId;
        protected final TskData.TSK_FS_ATTR_TYPE_ENUM attrType;
        protected final Set<TskData.TSK_FS_META_MODE_ENUM> modes;
        //local file support
        private boolean localPathSet = false; 
        private String localPath; 
        private String localAbsPath; 
        private volatile RandomAccessFile localFileHandle;
        private volatile java.io.File localFile;
        private TskData.EncodingType encodingType;
        //range support
        private List<TskFileRange> ranges;
        /*
         * path of parent directory
         */
        protected final String parentPath;
        protected TskData.FileKnown knownState;
        private boolean knownStateDirty = false;
        /*
         * md5 hash
         */
        protected String md5Hash;
        private boolean md5HashDirty = false;
        /*
         * SHA-256 hash
         */
        protected String sha256Hash;
        private boolean sha256HashDirty = false;
        
        /*
         * SHA-1 hash
         */
        protected String sha1Hash;
        private boolean sha1HashDirty = false;
        
        private TskData.CollectedStatus collected; // Collected status of file data     
        private boolean collectedDirty = false;
        
        private String mimeType;
        private boolean mimeTypeDirty = false;
        private static final Logger LOGGER = Logger.getLogger(AbstractFile.class.getName());
        private static final ResourceBundle BUNDLE = ResourceBundle.getBundle("org.sleuthkit.datamodel.Bundle");
        private long dataSourceObjectId;
        private final String extension;
        private final List<Attribute> fileAttributesCache = new ArrayList<Attribute>();
        private boolean loadedAttributesCacheFromDb = false;

        private final String ownerUid;  // string owner uid, for example a Windows SID.
        // different from the numeric uid which is more commonly found 
        // on Unix based file systems.
        private final Long osAccountObjId; // obj id of the owner's OS account, may be null
        
        private volatile String uniquePath;
        private volatile FileSystem parentFileSystem;
        
        private final boolean tryContentProviderStream;
        private Object contentProviderStreamLock = new Object();
        private SoftReference<ContentProviderStream> contentProviderStreamRef = null;

        AbstractFile(SleuthkitCase db,
                        long objId,
                        long dataSourceObjectId,
                        Long fileSystemObjectId,
                        TskData.TSK_FS_ATTR_TYPE_ENUM attrType, int attrId,
                        String name,
                        TskData.TSK_DB_FILES_TYPE_ENUM fileType,
                        long metaAddr, int metaSeq,
                        TSK_FS_NAME_TYPE_ENUM dirType, TSK_FS_META_TYPE_ENUM metaType,
                        TSK_FS_NAME_FLAG_ENUM dirFlag, short metaFlags,
                        long size,
                        long ctime, long crtime, long atime, long mtime,
                        short modes,
                        int uid, int gid,
                        String md5Hash, String sha256Hash, String sha1Hash, 
                        FileKnown knownState,
                        String parentPath,
                        String mimeType,
                        String extension,
                        String ownerUid,
                        Long osAccountObjectId,
                        TskData.CollectedStatus collected,
                        List<Attribute> fileAttributes) {
                super(db, objId, name);
                this.dataSourceObjectId = dataSourceObjectId;
                if (fileSystemObjectId != null) {
                        // When reading from the result set, nulls are converted to zeros.
                        // Switch it to null.
                        if (fileSystemObjectId > 0) {
                                this.fileSystemObjectId = fileSystemObjectId;
                        } else {
                                this.fileSystemObjectId = null;
                        }
                } else {
                        this.fileSystemObjectId = null;
                }
                this.attrType = attrType;
                this.attrId = attrId;
                this.fileType = fileType;
                this.metaAddr = metaAddr;
                this.metaSeq = metaSeq;
                this.dirType = dirType;
                this.metaType = metaType;
                this.dirFlag = dirFlag;
                this.metaFlags = TSK_FS_META_FLAG_ENUM.valuesOf(metaFlags);
                this.size = size;
                this.ctime = ctime;
                this.crtime = crtime;
                this.atime = atime;
                this.mtime = mtime;
                this.uid = uid;
                this.gid = gid;
                this.modes = TskData.TSK_FS_META_MODE_ENUM.valuesOf(modes);

                this.md5Hash = md5Hash;
                this.sha256Hash = sha256Hash;
                this.sha1Hash = sha1Hash;
                if (knownState == null) {
                        this.knownState = FileKnown.UNKNOWN;
                } else {
                        this.knownState = knownState;
                }
                this.parentPath = parentPath;
                this.mimeType = mimeType;
                this.extension = extension == null ? "" : extension;
                this.encodingType = TskData.EncodingType.NONE;
                this.ownerUid = ownerUid;
                this.osAccountObjId = osAccountObjectId;
                this.collected = collected;
                // any item that is marked as YES_REPO and there is a custom content provider for the db will attempt to use the content provider to provide data
                // this will be flipped to false if there is no content provider stream from the content provider for this file
                this.tryContentProviderStream = collected == CollectedStatus.YES_REPO && db.getContentProvider() != null;
                if (Objects.nonNull(fileAttributes) && !fileAttributes.isEmpty()) {
                        this.fileAttributesCache.addAll(fileAttributes);
                        loadedAttributesCacheFromDb = true;
                }
        }

        public TskData.TSK_DB_FILES_TYPE_ENUM getType() {
                return fileType;
        }

        public TskData.TSK_FS_ATTR_TYPE_ENUM getAttrType() {
                return attrType;
        }

        public int getAttributeId() {
                return attrId;
        }

        public long getCtime() {
                return ctime;
        }

        public String getCtimeAsDate() {
                return epochToTime(ctime);
        }

        public long getCrtime() {
                return crtime;
        }

        public String getCrtimeAsDate() {
                return epochToTime(crtime);
        }

        public long getAtime() {
                return atime;
        }

        public String getAtimeAsDate() {
                return epochToTime(atime);
        }

        public long getMtime() {
                return mtime;
        }

        public String getMtimeAsDate() {
                return epochToTime(mtime);
        }

        public int getUid() {
                return uid;
        }

        public int getGid() {
                return gid;
        }

        public long getMetaAddr() {
                return metaAddr;
        }

        public long getMetaSeq() {
                return metaSeq;
        }

        public String getModesAsString() {
                int mode = TskData.TSK_FS_META_MODE_ENUM.toInt(modes);
                String result = "";

                short isuid = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_ISUID.getMode();
                short isgid = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_ISGID.getMode();
                short isvtx = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_ISVTX.getMode();

                short irusr = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IRUSR.getMode();
                short iwusr = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IWUSR.getMode();
                short ixusr = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IXUSR.getMode();

                short irgrp = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IRGRP.getMode();
                short iwgrp = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IWGRP.getMode();
                short ixgrp = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IXGRP.getMode();

                short iroth = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IROTH.getMode();
                short iwoth = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IWOTH.getMode();
                short ixoth = TskData.TSK_FS_META_MODE_ENUM.TSK_FS_META_MODE_IXOTH.getMode();

                // first character = the Meta Type
                result += metaType.toString();

                // second and third characters = user permissions
                if ((mode & irusr) == irusr) {
                        result += "r"; //NON-NLS
                } else {
                        result += "-"; //NON-NLS
                }
                if ((mode & iwusr) == iwusr) {
                        result += "w"; //NON-NLS
                } else {
                        result += "-"; //NON-NLS
                }

                // fourth character = set uid
                if ((mode & isuid) == isuid) {
                        if ((mode & ixusr) == ixusr) {
                                result += "s"; //NON-NLS
                        } else {
                                result += "S"; //NON-NLS
                        }
                } else {
                        if ((mode & ixusr) == ixusr) {
                                result += "x"; //NON-NLS
                        } else {
                                result += "-"; //NON-NLS
                        }
                }

                // fifth and sixth characters = group permissions
                if ((mode & irgrp) == irgrp) {
                        result += "r"; //NON-NLS
                } else {
                        result += "-"; //NON-NLS
                }
                if ((mode & iwgrp) == iwgrp) {
                        result += "w"; //NON-NLS
                } else {
                        result += "-"; //NON-NLS
                }

                // seventh character = set gid
                if ((mode & isgid) == isgid) {
                        if ((mode & ixgrp) == ixgrp) {
                                result += "s"; //NON-NLS
                        } else {
                                result += "S"; //NON-NLS
                        }
                } else {
                        if ((mode & ixgrp) == ixgrp) {
                                result += "x"; //NON-NLS
                        } else {
                                result += "-"; //NON-NLS
                        }
                }

                // eighth and ninth character = other permissions
                if ((mode & iroth) == iroth) {
                        result += "r"; //NON-NLS
                } else {
                        result += "-"; //NON-NLS
                }
                if ((mode & iwoth) == iwoth) {
                        result += "w"; //NON-NLS
                } else {
                        result += "-"; //NON-NLS
                }

                // tenth character = sticky bit
                if ((mode & isvtx) == isvtx) {
                        if ((mode & ixoth) == ixoth) {
                                result += "t"; //NON-NLS
                        } else {
                                result += "T"; //NON-NLS
                        }
                } else {
                        if ((mode & ixoth) == ixoth) {
                                result += "x"; //NON-NLS
                        } else {
                                result += "-"; //NON-NLS
                        }
                }

                // check the result
                if (result.length() != 10) {
                        // throw error here
                        result = "ERROR"; //NON-NLS
                }
                return result;
        }

        public String getMIMEType() {
                return mimeType;
        }

        public void setMIMEType(String mimeType) {
                this.mimeType = mimeType;
                this.mimeTypeDirty = true;
        }

        public boolean isModeSet(TskData.TSK_FS_META_MODE_ENUM mode) {
                return modes.contains(mode);
        }

        public void setMd5Hash(String md5Hash) {
                this.md5Hash = md5Hash;
                this.md5HashDirty = true;
        }

        public String getMd5Hash() {
                return this.md5Hash;
        }

        public void setSha256Hash(String sha256Hash) {
                this.sha256Hash = sha256Hash;
                this.sha256HashDirty = true;
        }

        public String getSha256Hash() {
                return this.sha256Hash;
        }

        public void setSha1Hash(String sha1Hash) {
                this.sha1Hash = sha1Hash;
                this.sha1HashDirty = true;
        }

        public String getSha1Hash() {
                return this.sha1Hash;
        }
        
        public List<Attribute> getAttributes() throws TskCoreException {
                synchronized (this) {
                        if (!loadedAttributesCacheFromDb) {
                                ArrayList<Attribute> attributes = getSleuthkitCase().getBlackboard().getFileAttributes(this);
                                fileAttributesCache.clear();
                                fileAttributesCache.addAll(attributes);
                                loadedAttributesCacheFromDb = true;
                        }
                        return Collections.unmodifiableList(fileAttributesCache);
                }
        }

        public void addAttributes(Collection<Attribute> attributes, final SleuthkitCase.CaseDbTransaction caseDbTransaction) throws TskCoreException {

                if (Objects.isNull(attributes) || attributes.isEmpty()) {
                        throw new TskCoreException("Illegal Argument passed to addAttributes: null or empty attributes passed to addAttributes");
                }
                boolean isLocalTransaction = Objects.isNull(caseDbTransaction);
                SleuthkitCase.CaseDbTransaction localTransaction = isLocalTransaction ? getSleuthkitCase().beginTransaction() : null;
                SleuthkitCase.CaseDbConnection connection = isLocalTransaction ? localTransaction.getConnection() : caseDbTransaction.getConnection();

                try {
                        for (final Attribute attribute : attributes) {
                                attribute.setAttributeParentId(getId());
                                attribute.setCaseDatabase(getSleuthkitCase());
                                getSleuthkitCase().addFileAttribute(attribute, connection);
                        }

                        if (isLocalTransaction) {
                                localTransaction.commit();
                                localTransaction = null;
                        }
                        // append the new attributes if cache is already loaded.
                        synchronized (this) {
                                if (loadedAttributesCacheFromDb) {
                                        fileAttributesCache.addAll(attributes);
                                }
                        }
                } catch (SQLException ex) {
                        if (isLocalTransaction && null != localTransaction) {
                                try {
                                        localTransaction.rollback();
                                } catch (TskCoreException ex2) {
                                        LOGGER.log(Level.SEVERE, "Failed to rollback transaction after exception", ex2);
                                }
                        }
                        throw new TskCoreException("Error adding file attributes", ex);
                }
        }

        public void setKnown(TskData.FileKnown knownState) {
                // don't allow them to downgrade the known state
                if (this.knownState.compareTo(knownState) > 0) {
                        // ideally we'd return some kind of error, but 
                        // the API doesn't allow it
                        return;
                }
                this.knownState = knownState;
                this.knownStateDirty = true;
        }

        public TskData.FileKnown getKnown() {
                return knownState;
        }

        public String getNameExtension() {
                return extension;
        }

        @Override
        public long getSize() {
                return size;
        }

        public String getParentPath() {
                return parentPath;
        }

        @Override
        public Content getDataSource() throws TskCoreException {
                return getSleuthkitCase().getContentById(this.dataSourceObjectId);
        }

        public long getDataSourceObjectId() {
                return dataSourceObjectId;
        }
        
        public TskData.CollectedStatus getCollected() {
                return collected;
        }
        
        public void setCollected(TskData.CollectedStatus collected) {
                this.collected = collected;
                collectedDirty = true;
        }

        public List<TskFileRange> getRanges() throws TskCoreException {
                if (ranges == null) {
                        ranges = getSleuthkitCase().getFileRanges(this.getId());
                }
                return ranges;
        }

        public long convertToImgOffset(long fileOffset) throws TskCoreException {
                long imgOffset = -1;
                for (TskFileRange byteRange : getRanges()) {

                        // if fileOffset is within the current byteRange, calculate the image
                        // offset and break
                        long rangeLength = byteRange.getByteLen();
                        if (fileOffset < rangeLength) {
                                imgOffset = byteRange.getByteStart() + fileOffset;
                                break;
                        }

                        // otherwise, decrement fileOffset by the length of the current
                        // byte range and continue
                        fileOffset -= rangeLength;
                }
                return imgOffset;
        }

        public List<TskFileRange> convertToImgRanges(long fileOffset, long length) throws TskCoreException {
                if (fileOffset < 0 || length < 0) {
                        throw new TskCoreException("fileOffset and length must be non-negative");
                }

                List<TskFileRange> thisRanges = getRanges();
                List<TskFileRange> toRet = new ArrayList<>();

                long requestedEnd = fileOffset + length;

                // the number of bytes counted from the beginning of this file
                long bytesCounted = 0;

                for (int curRangeIdx = 0; curRangeIdx < thisRanges.size(); curRangeIdx++) {
                        // if we exceeded length of requested, then we are done
                        if (bytesCounted >= requestedEnd) {
                                break;
                        }

                        TskFileRange curRange = thisRanges.get(curRangeIdx);
                        long curRangeLen = curRange.getByteLen();
                        // the bytes counted when we reach the end of this range
                        long curRangeEnd = bytesCounted + curRangeLen;

                        // if fileOffset is less than current range's end and we have not 
                        // gone past the end we requested, then grab at least part of this 
                        // range.
                        if (fileOffset < curRangeEnd) {
                                // offset into range to be returned to user (0 if fileOffset <= bytesCounted)
                                long rangeOffset = Math.max(0, fileOffset - bytesCounted);

                                // calculate the new TskFileRange start by adding on the offset into the current range
                                long newRangeStart = curRange.getByteStart() + rangeOffset;

                                // how much this current range exceeds the length requested (or 0 if within the length requested)
                                long rangeOvershoot = Math.max(0, curRangeEnd - requestedEnd);

                                long newRangeLen = curRangeLen - rangeOffset - rangeOvershoot;
                                toRet.add(new TskFileRange(newRangeStart, newRangeLen, toRet.size()));
                        }

                        bytesCounted = curRangeEnd;
                }

                return toRet;
        }

        public boolean isVirtual() {
                return fileType.equals(TskData.TSK_DB_FILES_TYPE_ENUM.VIRTUAL_DIR)
                                || dirType.equals(TskData.TSK_FS_NAME_TYPE_ENUM.VIRT)
                                || metaType.equals(TskData.TSK_FS_META_TYPE_ENUM.TSK_FS_META_TYPE_VIRT);
        }

        public boolean isFile() {
                return metaType.equals(TSK_FS_META_TYPE_ENUM.TSK_FS_META_TYPE_REG)
                                || (metaType.equals(TSK_FS_META_TYPE_ENUM.TSK_FS_META_TYPE_UNDEF)
                                && dirType.equals(TSK_FS_NAME_TYPE_ENUM.REG));

        }

        public boolean isDir() {
                return (metaType.equals(TSK_FS_META_TYPE_ENUM.TSK_FS_META_TYPE_DIR)
                                || metaType.equals(TSK_FS_META_TYPE_ENUM.TSK_FS_META_TYPE_VIRT_DIR));
        }
        
        @Beta
        public int countChildrenOfType(List<TSK_FS_NAME_TYPE_ENUM> types) throws TskCoreException {
                return getSleuthkitCase().getAbstractFileChildrenCountByType(this, types);
        }

        public abstract boolean isRoot();

        public static String createNonUniquePath(String uniquePath) {

                // split the path into parts
                String[] pathSegments = uniquePath.split("/");

                // see if uniquePath had an image and/or volume name
                int index = 0;
                if (pathSegments[0].startsWith("img_")) { //NON-NLS
                        ++index;
                }
                if (pathSegments[1].startsWith("vol_")) { //NON-NLS
                        ++index;
                }

                // Assemble the non-unique path (skipping over the image and volume
                // name, if they exist).
                StringBuilder strbuf = new StringBuilder();
                for (; index < pathSegments.length; ++index) {
                        if (!pathSegments[index].isEmpty()) {
                                strbuf.append("/").append(pathSegments[index]);
                        }
                }

                return strbuf.toString();
        }

        public List<AbstractFile> listFiles() throws TskCoreException {
                // first, get all children
                List<Content> children = getChildren();

                // only keep those that are of type AbstractFile
                List<AbstractFile> files = new ArrayList<AbstractFile>();
                for (Content child : children) {
                        if (child instanceof AbstractFile) {
                                AbstractFile afChild = (AbstractFile) child;
                                files.add(afChild);
                        }
                }
                return files;
        }

        public TSK_FS_META_TYPE_ENUM getMetaType() {
                return metaType;
        }

        public String getMetaTypeAsString() {
                return metaType.toString();
        }

        public TSK_FS_NAME_TYPE_ENUM getDirType() {
                return dirType;
        }

        public String getDirTypeAsString() {
                return dirType.toString();
        }

        public boolean isDirNameFlagSet(TSK_FS_NAME_FLAG_ENUM flag) {
                return dirFlag == flag;
        }

        public String getDirFlagAsString() {
                return dirFlag.toString();
        }

        void setDirFlag(TSK_FS_NAME_FLAG_ENUM flag) {
                dirFlag = flag;
        }

        public String getMetaFlagsAsString() {
                String str = "";
                if (metaFlags.contains(TSK_FS_META_FLAG_ENUM.ALLOC)) {
                        str = TSK_FS_META_FLAG_ENUM.ALLOC.toString();
                } else if (metaFlags.contains(TSK_FS_META_FLAG_ENUM.UNALLOC)) {
                        str = TSK_FS_META_FLAG_ENUM.UNALLOC.toString();
                }
                return str;
        }

        public boolean isMetaFlagSet(TSK_FS_META_FLAG_ENUM metaFlag) {
                return metaFlags.contains(metaFlag);
        }

        void setMetaFlag(TSK_FS_META_FLAG_ENUM metaFlag) {
                metaFlags.add(metaFlag);
        }

        void removeMetaFlag(TSK_FS_META_FLAG_ENUM metaFlag) {
                metaFlags.remove(metaFlag);
        }

        short getMetaFlagsAsInt() {
                return TSK_FS_META_FLAG_ENUM.toInt(metaFlags);
        }
        
        private ContentProviderStream getContentProviderStream() throws TskCoreException {
                synchronized (contentProviderStreamLock) {
                        // try to get soft reference content provider stream
                        ContentProviderStream contentProviderStream = contentProviderStreamRef == null ? null : contentProviderStreamRef.get();
                        // load if not cached and then cache if present
                        if (contentProviderStream == null) {
                                ContentStreamProvider provider = getSleuthkitCase().getContentProvider();
                                contentProviderStream = provider == null ? null : provider.getContentStream(this).orElse(null);

                                if (contentProviderStream == null) {
                                        throw new TskCoreException(MessageFormat.format("Could not get content provider string for file with obj id: {0}, path: {1}",
                                                        getId(),
                                                        getUniquePath()));
                                }

                                this.contentProviderStreamRef = new SoftReference<>(contentProviderStream);
                        }

                        return contentProviderStream;
                }
        }
        
        @Override
        public final int read(byte[] buf, long offset, long len) throws TskCoreException {
                // try to use content provider stream if should use
                if (tryContentProviderStream) {
                        ContentProviderStream contentProviderStream = getContentProviderStream();
                        return contentProviderStream.read(buf, offset, len);
                } else if (localPathSet) {
                        //if localPath is set, use local, otherwise, use readCustom() supplied by derived class
                        return readLocal(buf, offset, len);
                } else {
                        return readInt(buf, offset, len);
                }

        }

        protected int readInt(byte[] buf, long offset, long len) throws TskCoreException {
                return 0;
        }

        protected final int readLocal(byte[] buf, long offset, long len) throws TskCoreException {
                if (!localPathSet) {
                        throw new TskCoreException(
                                        BUNDLE.getString("AbstractFile.readLocal.exception.msg1.text"));
                }

                if (isDir()) {
                        return 0;
                }

                // If the file is empty, just return that zero bytes were read.
                if (getSize() == 0) {
                        return 0;
                }

                loadLocalFile();

                int bytesRead = 0;

                if (localFileHandle == null) {
                        synchronized (this) {
                                if (localFileHandle == null) {
                                        try {
                                                localFileHandle = new RandomAccessFile(localFile, "r");
                                        } catch (FileNotFoundException ex) {
                                                final String msg = MessageFormat.format(BUNDLE.getString(
                                                                "AbstractFile.readLocal.exception.msg4.text"),
                                                                localAbsPath);
                                                LOGGER.log(Level.SEVERE, msg, ex);
                                                //file could have been deleted or moved
                                                throw new TskCoreException(msg, ex);
                                        }
                                }
                        }
                }

                try {
                        if (!encodingType.equals(TskData.EncodingType.NONE)) {
                                // The file is encoded, so we need to alter the offset to read (since there's
                                // a header on the encoded file) and then decode each byte
                                long encodedOffset = offset + EncodedFileUtil.getHeaderLength();

                                //move to the user request offset in the stream
                                long curOffset = localFileHandle.getFilePointer();
                                if (curOffset != encodedOffset) {
                                        localFileHandle.seek(encodedOffset);
                                }
                                bytesRead = localFileHandle.read(buf, 0, (int) len);
                                for (int i = 0; i < bytesRead; i++) {
                                        buf[i] = EncodedFileUtil.decodeByte(buf[i], encodingType);
                                }
                                return bytesRead;
                        } else {
                                //move to the user request offset in the stream
                                long curOffset = localFileHandle.getFilePointer();
                                if (curOffset != offset) {
                                        localFileHandle.seek(offset);
                                }
                                //note, we are always writing at 0 offset of user buffer
                                return localFileHandle.read(buf, 0, (int) len);
                        }
                } catch (IOException ex) {
                        final String msg = MessageFormat.format(BUNDLE.getString("AbstractFile.readLocal.exception.msg5.text"), localAbsPath);
                        LOGGER.log(Level.SEVERE, msg, ex);
                        //local file could have been deleted / moved
                        throw new TskCoreException(msg, ex);
                }
        }

        void setLocalFilePath(String localPath) {

                if (localPath == null || localPath.equals("")) {
                        this.localPath = "";
                        localAbsPath = null;
                        localPathSet = false;
                } else {
                        // It should always be the case that absolute paths start with slashes or a windows drive letter
                        // and relative paths do not, but some older versions of modules created derived file paths
                        // starting with slashes. So we first check if this file is a DerivedFile before looking at the path.
                        this.localPath = localPath;
                        if (this instanceof DerivedFile) {
                                // DerivedFiles always have relative paths
                                this.localAbsPath = getSleuthkitCase().getDbDirPath() + java.io.File.separator + localPath;
                        } else {
                                // If a path starts with a slash or with a Windows drive letter, then it is
                                // absolute. Otherwise it is relative.
                                if (localPath.startsWith("/") || localPath.startsWith("\\")
                                                || localPath.matches("[A-Za-z]:[/\\\\].*")) {
                                        this.localAbsPath = localPath;
                                } else {
                                        this.localAbsPath = getSleuthkitCase().getDbDirPath() + java.io.File.separator + localPath;
                                }
                        }
                        this.localPathSet = true;
                }
        }

        public String getLocalPath() {
                return localPath;
        }

        public String getLocalAbsPath() {
                return localAbsPath;
        }

        final void setEncodingType(TskData.EncodingType encodingType) {
                this.encodingType = encodingType;
        }

        public boolean exists() {
                if (tryContentProviderStream || !localPathSet) {
                        return true;
                } else {
                        try {
                                loadLocalFile();
                                return localFile.exists();
                        } catch (TskCoreException ex) {
                                LOGGER.log(Level.SEVERE, ex.getMessage());
                                return false;
                        }
                }
        }

        public boolean canRead() {
                if (tryContentProviderStream || !localPathSet) {
                        return true;
                } else {
                        try {
                                loadLocalFile();
                                return localFile.canRead();
                        } catch (TskCoreException ex) {
                                LOGGER.log(Level.SEVERE, ex.getMessage());
                                return false;
                        }
                }
        }

        private void loadLocalFile() throws TskCoreException {
                if (!localPathSet) {
                        throw new TskCoreException(
                                        BUNDLE.getString("AbstractFile.readLocal.exception.msg1.text"));
                }

                // already been set
                if (localFile != null) {
                        return;
                }

                synchronized (this) {
                        if (localFile == null) {
                                localFile = new java.io.File(localAbsPath);
                        }
                }
        }

        @Override
        public void close() {

                //close local file handle if set
                if (localFileHandle != null) {
                        synchronized (this) {
                                if (localFileHandle != null) {
                                        try {
                                                localFileHandle.close();
                                        } catch (IOException ex) {
                                                LOGGER.log(Level.SEVERE, "Could not close file handle for file: " + getParentPath() + getName(), ex); //NON-NLS
                                        }
                                        localFileHandle = null;
                                }
                        }
                }

        }

        @SuppressWarnings("deprecation")
        @Override
        protected void finalize() throws Throwable {
                try {
                        close();
                } finally {
                        super.finalize();
                }
        }

        @Override
        public String toString(boolean preserveState) {
                return super.toString(preserveState) + "AbstractFile [\t" //NON-NLS
                                + "\t" + "fileType " + fileType //NON-NLS
                                + "\tctime " + ctime //NON-NLS
                                + "\tcrtime " + crtime //NON-NLS
                                + "\t" + "mtime " + mtime + "\t" + "atime " + atime //NON-NLS
                                + "\t" + "attrId " + attrId //NON-NLS
                                + "\t" + "attrType " + attrType //NON-NLS
                                + "\t" + "dirFlag " + dirFlag + "\t" + "dirType " + dirType //NON-NLS
                                + "\t" + "uid " + uid //NON-NLS
                                + "\t" + "gid " + gid //NON-NLS
                                + "\t" + "metaAddr " + metaAddr + "\t" + "metaSeq " + metaSeq + "\t" + "metaFlags " + metaFlags //NON-NLS
                                + "\t" + "metaType " + metaType + "\t" + "modes " + modes //NON-NLS
                                + "\t" + "parentPath " + parentPath + "\t" + "size " + size //NON-NLS
                                + "\t" + "knownState " + knownState + "\t" + "md5Hash " + md5Hash + "\t" + "sha256Hash " + sha256Hash + "\t" + "sha1Hash " + sha1Hash//NON-NLS
                                + "\t" + "localPathSet " + localPathSet + "\t" + "localPath " + localPath //NON-NLS
                                + "\t" + "localAbsPath " + localAbsPath + "\t" + "localFile " + localFile //NON-NLS
                                + "]\t";
        }

        public enum MimeMatchEnum {

                UNDEFINED, 
                TRUE, 
                FALSE 
        }

        public MimeMatchEnum isMimeType(SortedSet<String> mimeTypes) {
                if (this.mimeType == null) {
                        return MimeMatchEnum.UNDEFINED;
                }
                if (mimeTypes.contains(this.mimeType)) {
                        return MimeMatchEnum.TRUE;
                }
                return MimeMatchEnum.FALSE;
        }

        public void save() throws TskCoreException {
                CaseDbTransaction transaction = null;
                try {
                        transaction = getSleuthkitCase().beginTransaction();
                        save(transaction);
                        transaction.commit();
                } catch (TskCoreException ex) {
                        if (transaction != null) {
                                transaction.rollback();
                        }
                        throw ex;
                }
        }

        public void save(CaseDbTransaction transaction) throws TskCoreException {
                if (!(md5HashDirty || sha256HashDirty || sha1HashDirty || mimeTypeDirty || knownStateDirty || collectedDirty)) {
                        return;
                }

                String updateSql = "";
                if (mimeTypeDirty) {
                        updateSql = "mime_type = '" + this.getMIMEType() + "'";
                }
                if (md5HashDirty) {
                        if (!updateSql.isEmpty()) {
                                updateSql += ", ";
                        }
                        updateSql += "md5 = '" + this.getMd5Hash() + "'";
                }
                if (sha256HashDirty) {
                        if (!updateSql.isEmpty()) {
                                updateSql += ", ";
                        }
                        updateSql += "sha256 = '" + this.getSha256Hash() + "'";
                }
                if (sha1HashDirty) {
                        if (!updateSql.isEmpty()) {
                                updateSql += ", ";
                        }
                        updateSql += "sha1 = '" + this.getSha1Hash() + "'";
                }
                if (knownStateDirty) {
                        if (!updateSql.isEmpty()) {
                                updateSql += ", ";
                        }
                        updateSql += "known = '" + this.getKnown().getFileKnownValue() + "'";
                }
                if (collectedDirty) {
                        if (!updateSql.isEmpty()) {
                                updateSql += ", ";
                        }
                        updateSql += "collected = '" + this.getCollected().getType() + "'";
                }
                updateSql = "UPDATE tsk_files SET " + updateSql + " WHERE obj_id = " + this.getId();

                SleuthkitCase.CaseDbConnection connection = transaction.getConnection();
                try (Statement statement = connection.createStatement()) {
                        connection.executeUpdate(statement, updateSql);
                        md5HashDirty = false;
                        sha256HashDirty = false;
                        sha1HashDirty = false;
                        mimeTypeDirty = false;
                        knownStateDirty = false;
                        collectedDirty = false;
                } catch (SQLException ex) {
                        throw new TskCoreException(String.format("Error updating properties of file %s (obj_id = %s)", getName(), getId()), ex);
                }
        }

        public Optional<String> getOwnerUid() {
                return Optional.ofNullable(ownerUid);
        }

        public Optional<Long> getOsAccountObjectId() {
                return Optional.ofNullable(osAccountObjId);
        }
        
        void setFileSystem(FileSystem parent) {
                parentFileSystem = parent;
        }
        
        public Optional<Long> getFileSystemObjectId() {
                return Optional.ofNullable(fileSystemObjectId);
        }
        
        public boolean hasFileSystem() {
                return fileSystemObjectId != null;
        }
        
        public FileSystem getFileSystem() throws TskCoreException {
                if (fileSystemObjectId == null) {
                        throw new TskCoreException("File with ID: " + this.getId() + " does not belong to a file system");
                }
                if (parentFileSystem == null) {
                        synchronized (this) {
                                if (parentFileSystem == null) {
                                        parentFileSystem = getSleuthkitCase().getFileSystemById(fileSystemObjectId, AbstractContent.UNKNOWN_ID);
                                }
                        }
                }
                return parentFileSystem;
        }
        
        @Override
        public String getUniquePath() throws TskCoreException {

                if (uniquePath == null) {
                        if (getFileSystemObjectId().isPresent()) {
                                // For file system files, construct the path using the path to
                                // the file system, the parent path, and the file name. FileSystem
                                // objects are cached so this is unlikely to perform any
                                // database operations.
                                StringBuilder sb = new StringBuilder();
                                sb.append(getFileSystem().getUniquePath());
                                if (! parentPath.isEmpty()) {
                                        sb.append(parentPath);
                                } else {
                                        // The parent path may not be set in older cases.
                                        sb.append("/");
                                }
                                sb.append(getName());
                                uniquePath = sb.toString();
                        } else {
                                if ((this instanceof LayoutFile) && (parentPath.equals("/"))) {
                                        // This may be the case where the layout file is a direct child of a 
                                        // volume. We want to make sure to include the volume information if present,
                                        // so go up the directory structure instead of using the optimized code.
                                        uniquePath = super.getUniquePath();
                                } else if (getName().equals(VirtualDirectory.NAME_CARVED) || getName().equals(VirtualDirectory.NAME_UNALLOC) || 
                                                parentPath.startsWith("/" + VirtualDirectory.NAME_CARVED) || parentPath.startsWith("/" + VirtualDirectory.NAME_UNALLOC)) {
                                        // We can make $Unalloc and $CarvedFiles under volumes without being part of a file system.
                                        // As above, we want to make sure to include the volume information if present,
                                        // so go up the directory structure instead of using the optimized code.
                                        uniquePath = super.getUniquePath();
                                } else {
                                        // Optimized code to use for most files. Construct the path
                                        // using the data source name, the parent path, and the file name.
                                        // DataSource objects are cached so this is unlikely to perform any
                                    // database operations.
                                        String dataSourceName = "";
                                        Content dataSource = getDataSource();
                                        if (dataSource != null) {
                                          dataSourceName = dataSource.getUniquePath(); 
                                        }
                                        if (! parentPath.isEmpty()) {
                                                uniquePath = dataSourceName + parentPath + getName();
                                        } else {
                                                // The parent path may not be set in older cases.
                                                uniquePath = dataSourceName + "/" + getName();
                                        }
                                }
                        }
                }
                return uniquePath;
        }

        @Deprecated
        @SuppressWarnings("deprecation")
        @Override
        public BlackboardArtifact newArtifact(int artifactTypeID) throws TskCoreException {
                return super.newArtifact(artifactTypeID);
        }

        @Override
        public DataArtifact newDataArtifact(BlackboardArtifact.Type artifactType, Collection<BlackboardAttribute> attributesList) throws TskCoreException {
                return super.newDataArtifact(artifactType, attributesList, getOsAccountObjectId().orElse(null));
        }

        @Deprecated
        @SuppressWarnings("deprecation")
        public short getAttrId() {
                /*
                 * NOTE: previously attrId used to be stored in AbstractFile as (signed)
                 * short even though it is stored as uint16 in TSK. In extremely rare
                 * occurrences attrId can be larger than what a signed short can hold
                 * (2^15). Changes were made to AbstractFile to store attrId as integer.
                 * Therefore this method has been deprecated. For backwards
                 * compatibility, attribute ids that are larger than 32K are converted
                 * to a negative number.
                 */
                return (short) attrId;  // casting to signed short converts values over 32K to negative values
        }

        @Deprecated
        protected void setLocalPath(String localPath, boolean isAbsolute) {
                setLocalFilePath(localPath);
        }

        /*
         * -------------------------------------------------------------------------
         * Util methods to convert / map the data
         * -------------------------------------------------------------------------
         */
        @Deprecated
        public static String epochToTime(long epoch) {
                return TimeUtilities.epochToTime(epoch);
        }

        @Deprecated
        public static String epochToTime(long epoch, TimeZone tzone) {
                return TimeUtilities.epochToTime(epoch, tzone);
        }

        @Deprecated
        public static long timeToEpoch(String time) {
                return TimeUtilities.timeToEpoch(time);
        }
        
        @Deprecated
        AbstractFile(SleuthkitCase db,
                        long objId,
                        long dataSourceObjectId,
                        Long fileSystemObjectId,
                        TskData.TSK_FS_ATTR_TYPE_ENUM attrType, int attrId,
                        String name,
                        TskData.TSK_DB_FILES_TYPE_ENUM fileType,
                        long metaAddr, int metaSeq,
                        TSK_FS_NAME_TYPE_ENUM dirType, TSK_FS_META_TYPE_ENUM metaType,
                        TSK_FS_NAME_FLAG_ENUM dirFlag, short metaFlags,
                        long size,
                        long ctime, long crtime, long atime, long mtime,
                        short modes,
                        int uid, int gid,
                        String md5Hash, String sha256Hash, String sha1Hash, 
                        FileKnown knownState,
                        String parentPath,
                        String mimeType,
                        String extension,
                        String ownerUid,
                        Long osAccountObjectId,
                        List<Attribute> fileAttributes) {
                this(db, objId, dataSourceObjectId, fileSystemObjectId, attrType, attrId, name, fileType, metaAddr, metaSeq, 
                                dirType, metaType, dirFlag, metaFlags, size, ctime, crtime, atime, mtime, modes, uid, gid, 
                                md5Hash, sha256Hash, sha1Hash, knownState, parentPath, mimeType, extension, 
                                ownerUid, osAccountObjectId, TskData.CollectedStatus.UNKNOWN, fileAttributes);
        }
}