// Index suggestions from existing Elasticsearch documents
DocumentReader reader = new ESSourceReader(
    client,
    suggester.settings(),
    "content-index",        // source index
    "document"             // document type
);

suggester.indexer()
    .indexFromDocument(reader, 2, 100)  // threads=2, batch=100
    .getResponse();
```

### Index from Query Logs

```java

/**
 * The {@code QueryLogReader} interface provides methods to read query logs and close the reader.
 * It extends the {@code Closeable} interface, ensuring that resources can be released when no longer needed.
 */
public interface QueryLogReader extends Closeable {
    /**
     * Reads a query log.
     * @return The query log.
     */
    QueryLog read();

    @Override
    void close();

 *
 * ESSourceReader reader = new ESSourceReader(client, settings, indexName);
 * reader.setScrollSize(1000); // Set the scroll size
 * reader.setLimitOfDocumentSize(1024 * 1024); // Limit document size to 1MB
 * reader.setQuery(QueryBuilders.termQuery("field", "value")); // Set a query
 *
 * Map<String, Object> document;
 * while ((document = reader.read()) != null) {
 *     // Process the document

        addDocument(indexName, client, num);

        ESSourceReader reader = new ESSourceReader(client, settings, indexName);
        reader.setScrollSize(1);
        reader.setLimitDocNumPercentage("1%");
        int count = 0;
        Set<String> valueSet = Collections.synchronizedSet(new HashSet<>());
        Map<String, Object> source;
        while ((source = reader.read()) != null) {

    client.setMaxConnectionsPerRoute(20);   // Per-host connections
    client.setConnectionTimeout(30000);     // Connection timeout
    client.setSocketTimeout(60000);         // Read timeout
});
```

### Memory Management

```java
// Configure memory usage
crawler.crawlerContext.setMaxAccessCount(10000);     // Limit crawled URLs

        /**
         * Constructor.
         * @param reader The reader.
         */
        public TextNormalizeContext(final Reader reader) {
            this.reader = reader;
        }

        /**
         * Executes the text processing operation on the provided reader.
         *
         * This method reads characters from the reader and processes them according to the following rules:

        }
    }

    private Reader getReader(final boolean reload) throws IOException {
        if (reload) {
            if (reloadableFile == null) {
                throw new IllegalArgumentException("reloadableFile is null.");
            }
            return new InputStreamReader(new FileInputStream(reloadableFile), StandardCharsets.UTF_8);
        }

        Reader reader = null;

        // Test user boost
        item.setUserBoost(2.0f);
        assertEquals(2.0f, item.getUserBoost(), 0.001f);

        // Test readings
        String[][] newReadings = { { "read1", "read2" }, { "read3" } };
        item.setReadings(newReadings);
        assertArrayEquals(newReadings, item.getReadings());

        // Test fields
        String[] fields = { "field1", "field2" };

        return inputStream.read(b, off, len);
    }

    /**
     * Reads some number of bytes from the input stream and stores them into the buffer array b.
     *
     * @param b the buffer into which the data is read
     * @return the total number of bytes read into the buffer, or -1 if there is no more data
     * @throws IOException if an I/O error occurs
     */
    @Override
    public int read(final byte[] b) throws IOException {

 */
public interface DocumentReader extends Closeable {
    /**
     * Reads a document and returns its contents as a map.
     *
     * @return a map containing the document's data, or null if there are no more documents to read.
     */
    Map<String, Object> read();

    @Override
    void close();