SOLR-9234: srcField parameter works only when all fields are captured in the /update/json/docs endpoint

solr/CHANGES.txt

@@ -47,6 +47,9 @@ Bug Fixes
 * SOLR-9161: Change SolrPluginUtils.invokeSetters implementation to accommodate setter variants.
   (Christine Poerschke, Steve Rowe, Uwe Schindler)
 
+* SOLR-9234: srcField parameter works only when all fields are captured in the /update/json/docs
+  endpoint (noble)
+
 Other Changes
 ----------------------
 

solr/core/src/java/org/apache/solr/util/RecordingJSONParser.java

@@ -23,45 +23,34 @@ import org.noggit.CharArr;
 import org.noggit.JSONParser;
 
 public class RecordingJSONParser extends JSONParser {
-  public RecordingJSONParser(Reader in) { super(in); }
+  static ThreadLocal<char[]> buf = new ThreadLocal<>();
+  private final char[] bufCopy;
+  //global position is the global position at the beginning of my buffer
+  private long globalPosition = 0;
 
   private StringBuilder sb = new StringBuilder();
-  private long position;
   private boolean objectStarted = false;
+  public long lastMarkedPosition = 0;
 
 
+  public RecordingJSONParser(Reader in) {
+    super(in, getChars());
+    bufCopy = buf.get();
+    buf.remove();
+  }
 
-  @Override
-  protected int getChar() throws IOException {
-    int aChar = super.getChar();
-    if(aChar == '{') objectStarted =true;
-    if(getPosition() >position) recordChar((char) aChar); // check before adding if a pushback happened ignore
-    position= getPosition();
-    return aChar;
+  static char[] getChars() {
+    buf.set(new char[8192]);
+    return buf.get();
   }
 
   private void recordChar(int aChar) {
-    if(objectStarted)
+    if (objectStarted) {
       sb.append((char) aChar);
+    } else if (aChar == '{') {
+      sb.append((char) aChar);
+      objectStarted = true;
     }
-  private void recordStr(String s) {
-    if(objectStarted) sb.append(s);
-  }
-
-  @Override
-  public CharArr getStringChars() throws IOException {
-    CharArr chars = super.getStringChars();
-    recordStr(chars.toString());
-    position = getPosition();
-    // if reading a String , the getStringChars do not return the closing single quote or double quote
-    //so, try to capture that
-    if(chars.getArray().length >chars.getStart()+chars.size()) {
-      char next = chars.getArray()[chars.getStart() + chars.size()];
-      if(next =='"' || next == '\'') {
-        recordChar(next);
-      }
-    }
-    return chars;
   }
 
   public void resetBuf() {
@@ -69,8 +58,36 @@ public class RecordingJSONParser extends JSONParser{
     objectStarted = false;
   }
 
+  @Override
+  public int nextEvent() throws IOException {
+    captureMissing();
+    return super.nextEvent();
+  }
+
+  private void captureMissing() {
+    long currPosition = getPosition() - globalPosition;
+    if(currPosition < 0){
+      System.out.println("ERROR");
+    }
+    if (currPosition > lastMarkedPosition) {
+      for (long i = lastMarkedPosition; i < currPosition; i++) {
+        recordChar(bufCopy[(int) i]);
+      }
+    }
+    lastMarkedPosition = currPosition;
+  }
+
+
+  @Override
+  protected void fill() throws IOException {
+    captureMissing();
+    super.fill();
+    this.globalPosition = getPosition();
+
+  }
 
   public String getBuf() {
+    captureMissing();
     if (sb != null) return sb.toString();
     return null;
   }

solr/solrj/src/test/org/apache/solr/common/util/TestJsonRecordReader.java

@@ -18,9 +18,12 @@ package org.apache.solr.common.util;
 
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.util.RecordingJSONParser;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.io.StringReader;
+import java.lang.invoke.MethodHandles;
 import java.lang.ref.WeakReference;
 import java.util.Arrays;
 import java.util.Collections;
@@ -30,6 +33,8 @@ import java.util.concurrent.atomic.AtomicReference;
 
 
 public class TestJsonRecordReader extends SolrTestCaseJ4 {
+  private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+
   public void testOneLevelSplit() throws IOException {
     String json = "{\n" +
         " \"a\":\"A\" ,\n" +
@@ -115,6 +120,53 @@ public class TestJsonRecordReader extends SolrTestCaseJ4 {
 
   }
 
+  public void testSrcField() throws Exception {
+    String json = "{\n" +
+        "  \"id\" : \"123\",\n" +
+        "  \"description\": \"Testing /json/docs srcField 1\",\n" +
+        "\n" +
+        "  \"nested_data\" : {\n" +
+        "    \"nested_inside\" : \"check check check 1\"\n" +
+        "  }\n" +
+        "}";
+    String json2 =
+        " {\n" +
+            "  \"id\" : \"345\",\n" +
+            "  \"description\": \"Testing /json/docs srcField 2\",\n" +
+            "\n" +
+            "  \"nested_data\" : {\n" +
+            "    \"nested_inside\" : \"check check check 2\"\n" +
+            "  }\n" +
+            "}";
+    JsonRecordReader streamer = JsonRecordReader.getInst("/", Arrays.asList("id:/id"));
+    RecordingJSONParser parser = new RecordingJSONParser(new StringReader(json + json2));
+
+
+    streamer.streamRecords(parser, new JsonRecordReader.Handler() {
+      int count = 0;
+
+      @Override
+      public void handle(Map<String, Object> record, String path) {
+        count++;
+        String buf = parser.getBuf();
+        parser.resetBuf();
+
+        Map m = (Map) Utils.fromJSONString(buf);
+        if (count == 1) {
+          assertEquals(m.get("id"), "123");
+          assertEquals(m.get("description"), "Testing /json/docs srcField 1");
+          assertEquals(((Map) m.get("nested_data")).get("nested_inside"), "check check check 1");
+        }
+        if (count++ == 2) {
+          assertEquals(m.get("id"), "345");
+          assertEquals(m.get("description"), "Testing /json/docs srcField 2");
+          assertEquals(((Map) m.get("nested_data")).get("nested_inside"), "check check check 2");
+        }
+      }
+    });
+
+  }
+
   public void testRecursiveWildCard() throws IOException {
     String json = "{\n" +
         " \"a\":\"A\" ,\n" +