Documentation from serialization/deserialization in NLP (#221)

* refactoring

Signed-off-by: Alexander Stoyakin <alexander.stoyakin@gmail.com>

* Javadocs

Signed-off-by: Alexander Stoyakin <alexander.stoyakin@gmail.com>

* Javadoc fixed

Signed-off-by: Alexander Stoyakin <alexander.stoyakin@gmail.com>

* Cleanup

Signed-off-by: Alexander Stoyakin <alexander.stoyakin@gmail.com>

deeplearning4j/deeplearning4j-nlp-parent/deeplearning4j-nlp/src/main/java/org/deeplearning4j/models/embeddings/loader/WordVectorSerializer.java

@@ -24,7 +24,6 @@ import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.io.LineIterator;
 import org.apache.commons.io.output.CloseShieldOutputStream;
-import org.deeplearning4j.exception.DL4JException;
 import org.deeplearning4j.exception.DL4JInvalidInputException;
 import org.deeplearning4j.models.embeddings.WeightLookupTable;
 import org.deeplearning4j.models.embeddings.inmemory.InMemoryLookupTable;
@@ -52,7 +51,6 @@ import org.deeplearning4j.text.sentenceiterator.BasicLineIterator;
 import org.deeplearning4j.text.tokenization.tokenizer.TokenPreProcess;
 import org.deeplearning4j.text.tokenization.tokenizerfactory.TokenizerFactory;
 import org.deeplearning4j.util.DL4JFileUtils;
-import org.nd4j.base.Preconditions;
 import org.nd4j.compression.impl.NoOp;
 import org.nd4j.linalg.api.ndarray.INDArray;
 import org.nd4j.linalg.exception.ND4JIllegalStateException;
@@ -68,8 +66,6 @@ import org.nd4j.util.OneTimeLogger;
 
 import java.io.*;
 import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -78,6 +74,80 @@ import java.util.zip.*;
 /**
  * This is utility class, providing various methods for WordVectors serialization
  *
+ * List of available serialization methods (please keep this list consistent with source code):
+ *
+ * <ul>
+ * <li>Serializers for Word2Vec:</li>
+ * {@link #writeWordVectors(WeightLookupTable, File)}
+ * {@link #writeWordVectors(WeightLookupTable, OutputStream)}
+ * {@link #writeWord2VecModel(Word2Vec, File)}
+ * {@link #writeWord2VecModel(Word2Vec, String)}
+ * {@link #writeWord2VecModel(Word2Vec, OutputStream)}
+ *
+ * <li>Deserializers for Word2Vec:</li>
+ * {@link #readWord2VecModel(File)}
+ * {@link #readWord2VecModel(String)}
+ * {@link #readWord2VecModel(File, boolean)}
+ * {@link #readWord2VecModel(String, boolean)}
+ * {@link #readAsBinaryNoLineBreaks(File)}
+ * {@link #readAsBinary(File)}
+ * {@link #readAsCsv(File)}
+ * {@link #readBinaryModel(File, boolean, boolean)}
+ * {@link #readWord2VecFromText(File, File, File, File, VectorsConfiguration)}
+ * {@link #readWord2Vec(String, boolean)}
+ * {@link #readWord2Vec(File, boolean)}
+ * {@link #readWord2Vec(InputStream, boolean)}
+ *
+ * <li>Serializers for ParaVec:</li>
+ * {@link #writeParagraphVectors(ParagraphVectors, File)}
+ * {@link #writeParagraphVectors(ParagraphVectors, String)}
+ * {@link #writeParagraphVectors(ParagraphVectors, OutputStream)}
+ *
+ * <li>Deserializers for ParaVec:</li>
+ * {@link #readParagraphVectors(File)}
+ * {@link #readParagraphVectors(String)}
+ * {@link #readParagraphVectors(InputStream)}
+ *
+ * <li>Serializers for GloVe:</li>
+ * {@link #writeWordVectors(Glove, File)}
+ * {@link #writeWordVectors(Glove, String)}
+ * {@link #writeWordVectors(Glove, OutputStream)}
+ *
+ * <li>Adapters</li>
+ * {@link #fromTableAndVocab(WeightLookupTable, VocabCache)}
+ * {@link #fromPair(Pair)}
+ * {@link #loadTxt(File)}
+ *
+ * <li>Serializers to tSNE format</li>
+ * {@link #writeTsneFormat(Glove, INDArray, File)}
+ * {@link #writeTsneFormat(Word2Vec, INDArray, File)}
+ *
+ * <li>FastText serializer:</li>
+ * {@link #writeWordVectors(FastText, File)}
+ *
+ * <li>FastText deserializer:</li>
+ * {@link #readWordVectors(File)}
+ *
+ * <li>SequenceVectors serializers:</li>
+ * {@link #writeSequenceVectors(SequenceVectors, OutputStream)}
+ * {@link #writeSequenceVectors(SequenceVectors, SequenceElementFactory, File)}
+ * {@link #writeSequenceVectors(SequenceVectors, SequenceElementFactory, String)}
+ * {@link #writeSequenceVectors(SequenceVectors, SequenceElementFactory, OutputStream)}
+ * {@link #writeLookupTable(WeightLookupTable, File)}
+ * {@link #writeVocabCache(VocabCache, File)}
+ * {@link #writeVocabCache(VocabCache, OutputStream)}
+ *
+ * <li>SequenceVectors deserializers:</li>
+ * {@link #readSequenceVectors(File, boolean)}
+ * {@link #readSequenceVectors(String, boolean)}
+ * {@link #readSequenceVectors(SequenceElementFactory, File)}
+ * {@link #readSequenceVectors(InputStream, boolean)}
+ * {@link #readSequenceVectors(SequenceElementFactory, InputStream)}
+ * {@link #readLookupTable(File)}
+ * {@link #readLookupTable(InputStream)}
+ *
+ * </ul>
+ *
  * @author Adam Gibson
  * @author raver119
  * @author alexander@skymind.io
@@ -97,7 +167,7 @@ public class WordVectorSerializer {
      * @throws IOException
      * @throws NumberFormatException
      */
-    private static Word2Vec readTextModel(File modelFile) throws IOException, NumberFormatException {
+    /*private static Word2Vec readTextModel(File modelFile) throws IOException, NumberFormatException {
         InMemoryLookupTable lookupTable;
         VocabCache cache;
         INDArray syn0;
@@ -142,7 +212,7 @@ public class WordVectorSerializer {
             ret.setLookupTable(lookupTable);
         }
         return ret;
-    }
+    }*/
 
     /**
      * Read a binary word2vec file.
@@ -173,8 +243,8 @@ public class WordVectorSerializer {
         try (BufferedInputStream bis = new BufferedInputStream(GzipUtils.isCompressedFilename(modelFile.getName())
                 ? new GZIPInputStream(new FileInputStream(modelFile)) : new FileInputStream(modelFile));
              DataInputStream dis = new DataInputStream(bis)) {
-            words = Integer.parseInt(readString(dis));
+            words = Integer.parseInt(ReadHelper.readString(dis));
-            size = Integer.parseInt(readString(dis));
+            size = Integer.parseInt(ReadHelper.readString(dis));
             syn0 = Nd4j.create(words, size);
             cache = new AbstractCache<>();
 
@@ -188,11 +258,11 @@ public class WordVectorSerializer {
             float[] vector = new float[size];
             for (int i = 0; i < words; i++) {
 
-                word = readString(dis);
+                word = ReadHelper.readString(dis);
                 log.trace("Loading " + word + " with word " + i);
 
                 for (int j = 0; j < size; j++) {
-                    vector[j] = readFloat(dis);
+                    vector[j] = ReadHelper.readFloat(dis);
                 }
 
                 if (cache.containsWord(word))
@@ -236,64 +306,6 @@ public class WordVectorSerializer {
 
     }
 
-    /**
-     * Read a float from a data input stream Credit to:
-     * https://github.com/NLPchina/Word2VEC_java/blob/master/src/com/ansj/vec/Word2VEC.java
-     *
-     * @param is
-     * @return
-     * @throws IOException
-     */
-    public static float readFloat(InputStream is) throws IOException {
-        byte[] bytes = new byte[4];
-        is.read(bytes);
-        return getFloat(bytes);
-    }
-
-    /**
-     * Read a string from a data input stream Credit to:
-     * https://github.com/NLPchina/Word2VEC_java/blob/master/src/com/ansj/vec/Word2VEC.java
-     *
-     * @param b
-     * @return
-     * @throws IOException
-     */
-    public static float getFloat(byte[] b) {
-        int accum = 0;
-        accum = accum | (b[0] & 0xff) << 0;
-        accum = accum | (b[1] & 0xff) << 8;
-        accum = accum | (b[2] & 0xff) << 16;
-        accum = accum | (b[3] & 0xff) << 24;
-        return Float.intBitsToFloat(accum);
-    }
-
-    /**
-     * Read a string from a data input stream Credit to:
-     * https://github.com/NLPchina/Word2VEC_java/blob/master/src/com/ansj/vec/Word2VEC.java
-     *
-     * @param dis
-     * @return
-     * @throws IOException
-     */
-    public static String readString(DataInputStream dis) throws IOException {
-        byte[] bytes = new byte[MAX_SIZE];
-        byte b = dis.readByte();
-        int i = -1;
-        StringBuilder sb = new StringBuilder();
-        while (b != 32 && b != 10) {
-            i++;
-            bytes[i] = b;
-            b = dis.readByte();
-            if (i == 49) {
-                sb.append(new String(bytes, "UTF-8"));
-                i = -1;
-                bytes = new byte[MAX_SIZE];
-            }
-        }
-        sb.append(new String(bytes, 0, i + 1, "UTF-8"));
-        return sb.toString();
-    }
-
     /**
      * This method writes word vectors to the given path.
      * Please note: this method doesn't load whole vocab/lookupTable into memory, so it's able to process large vocabularies served over network.
@@ -355,7 +367,7 @@ public class WordVectorSerializer {
                 val builder = new StringBuilder();
 
                 val l = element.getLabel();
-                builder.append(encodeB64(l)).append(" ");
+                builder.append(ReadHelper.encodeB64(l)).append(" ");
                 val vec = lookupTable.vector(element.getLabel());
                 for (int i = 0; i < vec.length(); i++) {
                     builder.append(vec.getDouble(i));
@@ -518,7 +530,7 @@ public class WordVectorSerializer {
             try (PrintWriter writer = new PrintWriter(new FileWriter(tempFileCodes))) {
                 for (int i = 0; i < vectors.getVocab().numWords(); i++) {
                     VocabWord word = vectors.getVocab().elementAtIndex(i);
-                    StringBuilder builder = new StringBuilder(encodeB64(word.getLabel())).append(" ");
+                    StringBuilder builder = new StringBuilder(ReadHelper.encodeB64(word.getLabel())).append(" ");
                     for (int code : word.getCodes()) {
                         builder.append(code).append(" ");
                     }
@@ -536,7 +548,7 @@ public class WordVectorSerializer {
             try (PrintWriter writer = new PrintWriter(new FileWriter(tempFileHuffman))) {
                 for (int i = 0; i < vectors.getVocab().numWords(); i++) {
                     VocabWord word = vectors.getVocab().elementAtIndex(i);
-                    StringBuilder builder = new StringBuilder(encodeB64(word.getLabel())).append(" ");
+                    StringBuilder builder = new StringBuilder(ReadHelper.encodeB64(word.getLabel())).append(" ");
                     for (int point : word.getPoints()) {
                         builder.append(point).append(" ");
                     }
@@ -554,7 +566,7 @@ public class WordVectorSerializer {
             try (PrintWriter writer = new PrintWriter(new FileWriter(tempFileFreqs))) {
                 for (int i = 0; i < vectors.getVocab().numWords(); i++) {
                     VocabWord word = vectors.getVocab().elementAtIndex(i);
-                    StringBuilder builder = new StringBuilder(encodeB64(word.getLabel())).append(" ")
+                    StringBuilder builder = new StringBuilder(ReadHelper.encodeB64(word.getLabel())).append(" ")
                             .append(word.getElementFrequency()).append(" ")
                             .append(vectors.getVocab().docAppearedIn(word.getLabel()));
 
@@ -638,7 +650,7 @@ public class WordVectorSerializer {
             try (PrintWriter writer = new PrintWriter(new FileWriter(tempFileCodes))) {
                 for (int i = 0; i < vectors.getVocab().numWords(); i++) {
                     VocabWord word = vectors.getVocab().elementAtIndex(i);
-                    StringBuilder builder = new StringBuilder(encodeB64(word.getLabel())).append(" ");
+                    StringBuilder builder = new StringBuilder(ReadHelper.encodeB64(word.getLabel())).append(" ");
                     for (int code : word.getCodes()) {
                         builder.append(code).append(" ");
                     }
@@ -656,7 +668,7 @@ public class WordVectorSerializer {
             try (PrintWriter writer = new PrintWriter(new FileWriter(tempFileHuffman))) {
                 for (int i = 0; i < vectors.getVocab().numWords(); i++) {
                     VocabWord word = vectors.getVocab().elementAtIndex(i);
-                    StringBuilder builder = new StringBuilder(encodeB64(word.getLabel())).append(" ");
+                    StringBuilder builder = new StringBuilder(ReadHelper.encodeB64(word.getLabel())).append(" ");
                     for (int point : word.getPoints()) {
                         builder.append(point).append(" ");
                     }
@@ -677,7 +689,7 @@ public class WordVectorSerializer {
             StringBuilder builder = new StringBuilder();
             for (VocabWord word : vectors.getVocab().tokens()) {
                 if (word.isLabel())
-                    builder.append(encodeB64(word.getLabel())).append("\n");
+                    builder.append(ReadHelper.encodeB64(word.getLabel())).append("\n");
             }
             IOUtils.write(builder.toString().trim(), zipfile, StandardCharsets.UTF_8);
 
@@ -688,7 +700,7 @@ public class WordVectorSerializer {
             try (PrintWriter writer = new PrintWriter(new FileWriter(tempFileFreqs))) {
                 for (int i = 0; i < vectors.getVocab().numWords(); i++) {
                     VocabWord word = vectors.getVocab().elementAtIndex(i);
-                    builder = new StringBuilder(encodeB64(word.getLabel())).append(" ").append(word.getElementFrequency())
+                    builder = new StringBuilder(ReadHelper.encodeB64(word.getLabel())).append(" ").append(word.getElementFrequency())
                             .append(" ").append(vectors.getVocab().docAppearedIn(word.getLabel()));
 
                     writer.println(builder.toString().trim());
@@ -744,7 +756,7 @@ public class WordVectorSerializer {
                 try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))) {
                     String line;
                     while ((line = reader.readLine()) != null) {
-                        VocabWord word = vectors.getVocab().tokenFor(decodeB64(line.trim()));
+                        VocabWord word = vectors.getVocab().tokenFor(ReadHelper.decodeB64(line.trim()));
                         if (word != null) {
                             word.markAsLabel(true);
                         }
@@ -836,7 +848,7 @@ public class WordVectorSerializer {
                     String line;
                     while ((line = reader.readLine()) != null) {
                         String[] split = line.split(" ");
-                        VocabWord word = w2v.getVocab().tokenFor(decodeB64(split[0]));
+                        VocabWord word = w2v.getVocab().tokenFor(ReadHelper.decodeB64(split[0]));
                         word.setElementFrequency((long) Double.parseDouble(split[1]));
                         word.setSequencesCount((long) Double.parseDouble(split[2]));
                     }
@@ -946,7 +958,7 @@ public class WordVectorSerializer {
         reader = new BufferedReader(new FileReader(h_points));
         while ((line = reader.readLine()) != null) {
             String[] split = line.split(" ");
-            VocabWord word = vocab.wordFor(decodeB64(split[0]));
+            VocabWord word = vocab.wordFor(ReadHelper.decodeB64(split[0]));
             List<Integer> points = new ArrayList<>();
             for (int i = 1; i < split.length; i++) {
                 points.add(Integer.parseInt(split[i]));
@@ -960,7 +972,7 @@ public class WordVectorSerializer {
         reader = new BufferedReader(new FileReader(h_codes));
         while ((line = reader.readLine()) != null) {
             String[] split = line.split(" ");
-            VocabWord word = vocab.wordFor(decodeB64(split[0]));
+            VocabWord word = vocab.wordFor(ReadHelper.decodeB64(split[0]));
             List<Byte> codes = new ArrayList<>();
             for (int i = 1; i < split.length; i++) {
                 codes.add(Byte.parseByte(split[i]));
@@ -1704,7 +1716,7 @@ public class WordVectorSerializer {
             if (line.isEmpty())
                 line = iter.nextLine();
             String[] split = line.split(" ");
-            String word = decodeB64(split[0]); //split[0].replaceAll(whitespaceReplacement, " ");
+            String word = ReadHelper.decodeB64(split[0]); //split[0].replaceAll(whitespaceReplacement, " ");
             VocabWord word1 = new VocabWord(1.0, word);
 
             word1.setIndex(cache.numWords());
@@ -1994,7 +2006,13 @@ public class WordVectorSerializer {
     private static final String SYN1_ENTRY = "syn1.bin";
     private static final String SYN1_NEG_ENTRY = "syn1neg.bin";
 
-
+    /**
+     * This method saves specified SequenceVectors model to target  OutputStream
+     *
+     * @param vectors SequenceVectors model
+     * @param stream  Target output stream
+     * @param <T>
+     */
     public static <T extends SequenceElement> void writeSequenceVectors(@NonNull SequenceVectors<T> vectors,
                                                                         @NonNull OutputStream stream)
             throws IOException {
@@ -2040,7 +2058,13 @@ public class WordVectorSerializer {
         }
     }
 
-
+    /**
+     * This method loads SequenceVectors from specified file path
+     *
+     * @param path String
+     * @param readExtendedTables boolean
+     * @param <T>
+     */
     public static <T extends SequenceElement> SequenceVectors<T> readSequenceVectors(@NonNull String path,
                                                                                      boolean readExtendedTables)
             throws IOException {
@@ -2050,6 +2074,14 @@ public class WordVectorSerializer {
         return vectors;
     }
 
+    /**
+     * This method loads SequenceVectors from specified file path
+     *
+     * @param file File
+     * @param readExtendedTables boolean
+     * @param <T>
+     */
+
     public static <T extends SequenceElement> SequenceVectors<T> readSequenceVectors(@NonNull File file,
                                                                                      boolean readExtendedTables)
             throws IOException {
@@ -2058,6 +2090,13 @@ public class WordVectorSerializer {
         return vectors;
     }
 
+    /**
+     * This method loads SequenceVectors from specified input stream
+     *
+     * @param stream InputStream
+     * @param readExtendedTables boolean
+     * @param <T>
+     */
     public static <T extends SequenceElement> SequenceVectors<T> readSequenceVectors(@NonNull InputStream stream,
                                                                                      boolean readExtendedTables)
             throws IOException {
@@ -2381,6 +2420,12 @@ public class WordVectorSerializer {
         }
     }
 
+    /**
+     * This method loads Word2Vec model from binary file
+     *
+     * @param file File
+     * @return  Word2Vec
+     */
     public static Word2Vec readAsBinary(@NonNull File file) {
         boolean originalPeriodic = Nd4j.getMemoryManager().isPeriodicGcActive();
         int originalFreq = Nd4j.getMemoryManager().getOccasionalGcFrequency();
@@ -2403,6 +2448,12 @@ public class WordVectorSerializer {
         }
     }
 
+    /**
+     * This method loads Word2Vec model from csv file
+     *
+     * @param file File
+     * @return Word2Vec
+     */
     public static Word2Vec readAsCsv(@NonNull File file) {
 
         Word2Vec vec;
@@ -2491,7 +2542,7 @@ public class WordVectorSerializer {
                 String line;
                 while ((line = reader.readLine()) != null) {
                     String[] split = line.split(" ");
-                    VocabWord word = new VocabWord(Double.valueOf(split[1]), decodeB64(split[0]));
+                    VocabWord word = new VocabWord(Double.valueOf(split[1]), ReadHelper.decodeB64(split[0]));
                     word.setIndex(cnt.getAndIncrement());
                     word.incrementSequencesCount(Long.valueOf(split[2]));
 
@@ -2669,7 +2720,7 @@ public class WordVectorSerializer {
      *
      * In return you get StaticWord2Vec model, which might be used as lookup table only in multi-gpu environment.
      *
-     * @param file File should point to previously saved w2v model
+     * @param inputStream InputStream should point to previously saved w2v model
      * @return
      */
     public static WordVectors loadStaticModel(InputStream inputStream) throws IOException {
@@ -2685,6 +2736,17 @@ public class WordVectorSerializer {
     }
 
     // TODO: this method needs better name :)
+    /**
+     * This method restores previously saved w2v model. File can be in one of the following formats:
+     * 1) Binary model, either compressed or not. Like well-known Google Model
+     * 2) Popular CSV word2vec text format
+     * 3) DL4j compressed format
+     *
+     * In return you get StaticWord2Vec model, which might be used as lookup table only in multi-gpu environment.
+     *
+     * @param file File
+     * @return
+     */
     public static WordVectors loadStaticModel(@NonNull File file) {
         if (!file.exists() || file.isDirectory())
             throw new RuntimeException(
@@ -2843,8 +2905,8 @@ public class WordVectorSerializer {
                 throw new RuntimeException(e);
             }
             try {
-                numWords = Integer.parseInt(readString(stream));
+                numWords = Integer.parseInt(ReadHelper.readString(stream));
-                vectorLength = Integer.parseInt(readString(stream));
+                vectorLength = Integer.parseInt(ReadHelper.readString(stream));
             } catch (IOException e) {
                 throw new RuntimeException(e);
             }
@@ -2858,13 +2920,13 @@ public class WordVectorSerializer {
         @Override
         public Pair<VocabWord, float[]> next() {
             try {
-                String word = readString(stream);
+                String word = ReadHelper.readString(stream);
                 VocabWord element = new VocabWord(1.0, word);
                 element.setIndex(idxCounter.getAndIncrement());
 
                 float[] vector = new float[vectorLength];
                 for (int i = 0; i < vectorLength; i++) {
-                    vector[i] = readFloat(stream);
+                    vector[i] = ReadHelper.readFloat(stream);
                 }
 
                 return Pair.makePair(element, vector);
@@ -2913,7 +2975,7 @@ public class WordVectorSerializer {
 
             String[] split = nextLine.split(" ");
 
-            VocabWord word = new VocabWord(1.0, decodeB64(split[0]));
+            VocabWord word = new VocabWord(1.0, ReadHelper.decodeB64(split[0]));
             word.setIndex(idxCounter.getAndIncrement());
 
             float[] vector = new float[split.length - 1];
@@ -2937,26 +2999,12 @@ public class WordVectorSerializer {
         }
     }
 
-    public static String encodeB64(String word) {
+    /**
-        try {
+     * This method saves Word2Vec model to output stream
-            return "B64:" + Base64.encodeBase64String(word.getBytes("UTF-8")).replaceAll("(\r|\n)", "");
+     *
-        } catch (Exception e) {
+     * @param word2Vec Word2Vec
-            throw new RuntimeException(e);
+     * @param stream OutputStream
-        }
+     */
-    }
-
-    public static String decodeB64(String word) {
-        if (word.startsWith("B64:")) {
-            String arp = word.replaceFirst("B64:", "");
-            try {
-                return new String(Base64.decodeBase64(arp), "UTF-8");
-            } catch (Exception e) {
-                throw new RuntimeException(e);
-            }
-        } else
-            return word;
-    }
-
     public static void writeWord2Vec(@NonNull Word2Vec word2Vec, @NonNull OutputStream stream)
             throws IOException {
 
@@ -2968,6 +3016,13 @@ public class WordVectorSerializer {
         writeSequenceVectors(vectors, stream);
     }
 
+    /**
+     * This method restores Word2Vec model from file
+     *
+     * @param path String
+     * @param readExtendedTables booleab
+     * @return Word2Vec
+     */
     public static Word2Vec readWord2Vec(@NonNull String path, boolean readExtendedTables)
             throws  IOException {
 
@@ -2976,6 +3031,12 @@ public class WordVectorSerializer {
         return word2Vec;
     }
 
+    /**
+     * This method saves table of weights to file
+     *
+     * @param weightLookupTable WeightLookupTable
+     * @param file File
+     */
     public static <T extends SequenceElement>  void writeLookupTable(WeightLookupTable<T> weightLookupTable,
                                                                      @NonNull File file) throws IOException {
         try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file),
@@ -3038,7 +3099,7 @@ public class WordVectorSerializer {
                     headerRead = true;
                     weightLookupTable = new InMemoryLookupTable.Builder().cache(vocabCache).vectorLength(layerSize).build();
                 } else {
-                    String label = decodeB64(tokens[0]);
+                    String label = ReadHelper.decodeB64(tokens[0]);
                     int freq = Integer.parseInt(tokens[1]);
                     int rows = Integer.parseInt(tokens[2]);
                     int cols = Integer.parseInt(tokens[3]);
@@ -3071,6 +3132,13 @@ public class WordVectorSerializer {
         return weightLookupTable;
     }
 
+    /**
+     * This method loads Word2Vec model from file
+     *
+     * @param file File
+     * @param readExtendedTables boolean
+     * @return Word2Vec
+     */
     public static Word2Vec readWord2Vec(@NonNull File file, boolean readExtendedTables)
             throws IOException {
 
@@ -3078,6 +3146,13 @@ public class WordVectorSerializer {
         return word2Vec;
     }
 
+    /**
+     * This method loads Word2Vec model from input stream
+     *
+     * @param stream InputStream
+     * @param readExtendedTable boolean
+     * @return Word2Vec
+     */
     public static Word2Vec readWord2Vec(@NonNull InputStream stream,
                                          boolean readExtendedTable) throws IOException {
         SequenceVectors<VocabWord> vectors = readSequenceVectors(stream, readExtendedTable);
@@ -3088,6 +3163,12 @@ public class WordVectorSerializer {
         return word2Vec;
     }
 
+    /**
+     * This method loads FastText model to file
+     *
+     * @param vectors FastText
+     * @param path File
+     */
     public static void writeWordVectors(@NonNull FastText vectors, @NonNull File path) throws IOException {
         ObjectOutputStream outputStream = null;
         try {
@@ -3106,6 +3187,11 @@ public class WordVectorSerializer {
         }
     }
 
+    /**
+     * This method unloads FastText model from file
+     *
+     * @param path File
+     */
      public static FastText readWordVectors(File path) {
         FastText result = null;
         try {
@@ -3124,6 +3210,13 @@ public class WordVectorSerializer {
         return result;
     }
 
+    /**
+     * This method prints memory usage to log
+     *
+     * @param numWords
+     * @param vectorLength
+     * @param numTables
+     */
     public static void printOutProjectedMemoryUse(long numWords, int vectorLength, int numTables) {
         double memSize = numWords * vectorLength * Nd4j.sizeOfDataType() * numTables;
 
@@ -3144,4 +3237,102 @@ public class WordVectorSerializer {
         OneTimeLogger.info(log, "Projected memory use for model: [{} {}]", String.format("%.2f", value), sfx);
 
     }
+
+    /**
+    *   Helper static methods to read data from input stream.
+    */
+    private static class ReadHelper {
+        /**
+         * Read a float from a data input stream Credit to:
+         * https://github.com/NLPchina/Word2VEC_java/blob/master/src/com/ansj/vec/Word2VEC.java
+         *
+         * @param is
+         * @return
+         * @throws IOException
+         */
+        private static float readFloat(InputStream is) throws IOException {
+            byte[] bytes = new byte[4];
+            is.read(bytes);
+            return getFloat(bytes);
+        }
+
+        /**
+         * Read a string from a data input stream Credit to:
+         * https://github.com/NLPchina/Word2VEC_java/blob/master/src/com/ansj/vec/Word2VEC.java
+         *
+         * @param b
+         * @return
+         * @throws IOException
+         */
+        private static float getFloat(byte[] b) {
+            int accum = 0;
+            accum = accum | (b[0] & 0xff) << 0;
+            accum = accum | (b[1] & 0xff) << 8;
+            accum = accum | (b[2] & 0xff) << 16;
+            accum = accum | (b[3] & 0xff) << 24;
+            return Float.intBitsToFloat(accum);
+        }
+
+        /**
+         * Read a string from a data input stream Credit to:
+         * https://github.com/NLPchina/Word2VEC_java/blob/master/src/com/ansj/vec/Word2VEC.java
+         *
+         * @param dis
+         * @return
+         * @throws IOException
+         */
+        private static String readString(DataInputStream dis) throws IOException {
+            byte[] bytes = new byte[MAX_SIZE];
+            byte b = dis.readByte();
+            int i = -1;
+            StringBuilder sb = new StringBuilder();
+            while (b != 32 && b != 10) {
+                i++;
+                bytes[i] = b;
+                b = dis.readByte();
+                if (i == 49) {
+                    sb.append(new String(bytes, "UTF-8"));
+                    i = -1;
+                    bytes = new byte[MAX_SIZE];
+                }
+            }
+            sb.append(new String(bytes, 0, i + 1, "UTF-8"));
+            return sb.toString();
+        }
+
+        private static final String B64 = "B64:";
+
+        /**
+         * Encode input string
+         *
+         * @param word String
+         * @return String
+         */
+        private static String encodeB64(String word) {
+            try {
+                return B64 + Base64.encodeBase64String(word.getBytes("UTF-8")).replaceAll("(\r|\n)", "");
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        }
+
+        /**
+         * Encode input string
+         *
+         * @param word String
+         * @return String
+         */
+
+        private static String decodeB64(String word) {
+            if (word.startsWith(B64)) {
+                String arp = word.replaceFirst(B64, "");
+                try {
+                    return new String(Base64.decodeBase64(arp), "UTF-8");
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            } else
+                return word;
+        }
+    }
 }