chore: rewrite InfluxQLQueryApiImpl.parseTags to handle escaped equals and backslashes.

Author: karel-rehor

client/src/main/java/com/influxdb/client/internal/InfluxQLQueryApiImpl.java

@@ -180,50 +180,82 @@ static InfluxQLQueryResult readInfluxQLResult(
         return new InfluxQLQueryResult(results);
     }
 
-    private static int indexOfUnescapedChar(@Nonnull final String str, final char ch) {
-        char[] chars = str.toCharArray();
-        for (int i = 1; i < chars.length; i++) { // ignore first value
-            if (chars[i] == ch && chars[i - 1] != '\\') {
-                return i;
-            }
-        }
-        return -1;
-    }
-
-    /*
-       This works on the principle that the copula '=' is the _governing verb_ of any key to value
-       expression.  So parsing begins based on the verb ('=') not on the assumed expression termination
-       character (',').  The Left and right values of the split based on ('=') are collected and checked for
-       the correct statement terminator (an unescaped ',').  Any value on the left of an unescaped ',' is a
-       value.  Any value on the right is a key.
-     */
     private static Map<String, String> parseTags(@Nonnull final String value) {
         final Map<String, String> tags = new HashMap<>();
-        if (!value.isEmpty()) {
-            String[] chunks = value.split("=");
-            String currentKey = "";
-            String currentValue = "";
-            String nextKey = "";
-            for (int i = 0; i < chunks.length; i++) {
-                if (i == 0) { // first element will be a key on its own.
-                    nextKey = chunks[i];
-                } else if (i == chunks.length - 1) { // the last element will be a value on its own.
-                    currentValue = chunks[i];
-                } else { // check for legitimate keys and values
-                    int commaIndex = indexOfUnescapedChar(chunks[i], ',');
-                    if (commaIndex != -1) {
-                        currentValue = chunks[i].substring(0, commaIndex);
-                        nextKey = chunks[i].substring(commaIndex + 1);
-                    }
+        if (value.isEmpty()) {
+            return tags;
+        }
+
+        StringBuilder currentKey  = new StringBuilder();
+        StringBuilder currentValue = new StringBuilder();
+        boolean inValue = false;
+        boolean escaped = false;
+
+        for (int i = 0; i < value.length(); i++) {
+            char c = value.charAt(i);
+
+            if (escaped) {
+                // current character is escaped - treat it as a literal
+                if (inValue) {
+                    currentValue.append(c);
+                } else {
+                    currentKey.append(c);
                 }
-                if (i > 0) {
-                    // be sure to surround keys and values containing escapes with double quotes
+                escaped = false;
+                continue;
+            }
+
+            if (c == '\\') {
+                // start escape sequence
+                // preserve escape character
+                if (inValue) {
+                    currentValue.append(c);
+                } else {
+                    currentKey.append(c);
+                }
+                escaped = true;
+                continue;
+            }
+
+            if (!inValue && c == '=') {
+                // unescaped '=' marks copula
+                inValue = true;
+                continue;
+            }
+
+            if (inValue && c == ',') {
+                // unescaped comma separates key value pairs
+                // finalize
+                String key = currentKey.toString();
+                String val = currentValue.toString();
+                if (!key.isEmpty()) {
                     tags.put(
-                        currentKey.contains("\\") ? "\"" + currentKey + "\"" : currentKey,
-                        currentValue.contains("\\") ? "\"" + currentValue + "\"" : currentValue
+                        key.contains("\\") ? "\"" + key + "\"" : key,
+                        val.contains("\\") ? "\"" + val + "\"" : val
                     );
                 }
-                currentKey = nextKey;
+                currentKey.setLength(0);
+                currentValue.setLength(0);
+                inValue = false;
+                continue;
+            }
+
+            if (inValue) {
+                currentValue.append(c);
+            } else {
+                currentKey.append(c);
+            }
+        }
+
+        // finalize last key/value pair if any
+        String key =  currentKey.toString();
+        String val = currentValue.toString();
+        if (!key.isEmpty() || inValue) {
+            if (!key.isEmpty()) {
+                tags.put(
+                    key.contains("\\") ? "\"" + key + "\"" : key,
+                    val.contains("\\") ? "\"" + val + "\"" : val
+                );
             }
         }
 

client/src/test/java/com/influxdb/client/internal/InfluxQLQueryApiImplTest.java

@@ -72,7 +72,7 @@ void readInfluxQLResultWithTagCommas() throws IOException {
 			"model\\,\\ uin=C3PO", // tag with comma space in key
 			"model\\,\\ uin=Droid\\, C3PO", // tag with comma space in key and value
 			"model\\,\\ uin=Droid\\,\\ C3PO,location=Cheb\\,\\ CZ,branch=Munchen\\,\\ DE", // comma space in key and val
-			"silly\\,long\\,tag=a\\,b\\,\\ c\\,\\ d", // multiple commas in key and value
+			"silly\\,\\=long\\,tag=a\\,b\\\\\\,\\ c\\,\\ d", // multi commas in k and v plus escaped reserved chars
 			"region=us\\,\\ east-1,host\\,\\ name=ser\\,\\ ver1" // legacy broken tags
 		);
 
@@ -125,7 +125,7 @@ void readInfluxQLResultWithTagCommas() throws IOException {
 			// 9. multiple commas in key and value
 		    new AbstractMap.SimpleImmutableEntry<>(testTags.get(8),
 			    new HashMap<String,String>() {{
-				    put("\"silly\\,long\\,tag\"", "\"a\\,b\\,\\ c\\,\\ d\"");
+				    put("\"silly\\,\\=long\\,tag\"", "\"a\\,b\\\\\\,\\ c\\,\\ d\"");
 			    }}),
 			// legacy broken tags
 			new AbstractMap.SimpleImmutableEntry<>(testTags.get(9),
@@ -161,6 +161,13 @@ void readInfluxQLResultWithTagCommas() throws IOException {
 					InfluxQLQueryResult.Series.Record valRec = s.getValues().get(0);
 					Assertions.assertThat(valRec.getValueByKey("first")).isEqualTo(Double.valueOf("42.0"));
 					Assertions.assertThat(valRec.getValueByKey("time")).isEqualTo(Instant.ofEpochSecond(1483225200L));
+				} else if (index == 10) {
+					Assertions.assertThat(s.getColumns()).containsOnlyKeys("time", "usage_user", "usage_system");
+					InfluxQLQueryResult.Series.Record valRec = s.getValues().get(0);
+					// No value extractor created for "cpu" series
+					Assertions.assertThat(valRec.getValueByKey("time")).isEqualTo("1483225200");
+					Assertions.assertThat(valRec.getValueByKey("usage_user")).isEqualTo("13.57");
+					Assertions.assertThat(valRec.getValueByKey("usage_system")).isEqualTo("1.4");
 				}
 			}
 		}