Merge pull request #23770 from vespa-engine/bratseth/embedder-syntax-5

Bratseth/embedder syntax 5

2 files changed, 219 insertions, 286 deletions

diff --git a/vespajlib/abi-spec.json b/vespajlib/abi-spec.json
index fbf1203acdf..8714285acd8 100644
--- a/vespajlib/abi-spec.json
+++ b/vespajlib/abi-spec.json
@@ -3362,6 +3362,7 @@
       "public static javax.xml.parsers.DocumentBuilder getDocumentBuilder(java.lang.String, java.lang.ClassLoader, boolean)",
       "public static java.util.List getChildren(org.w3c.dom.Element)",
       "public static java.util.List getChildren(org.w3c.dom.Element, java.lang.String)",
+      "public static java.util.Optional attribute(java.lang.String, org.w3c.dom.Element)",
       "public static java.lang.String getValue(org.w3c.dom.Element)",
       "public static org.w3c.dom.Element getChild(org.w3c.dom.Element, java.lang.String)",
       "public static java.lang.String getNodePath(org.w3c.dom.Node, java.lang.String)",
diff --git a/vespajlib/src/main/java/com/yahoo/text/XML.java b/vespajlib/src/main/java/com/yahoo/text/XML.java
index 6aa42773ac0..255e6a67429 100644
--- a/vespajlib/src/main/java/com/yahoo/text/XML.java
+++ b/vespajlib/src/main/java/com/yahoo/text/XML.java
@@ -18,6 +18,7 @@ import java.io.Reader;
 import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 
 /**
  * Static XML utility methods
@@ -29,280 +30,39 @@ import java.util.List;
  */
 public class XML {
 
-    /**
-     * The point of this weird class and the jumble of abstract methods is
-     * linking the scan for characters that must be quoted into the quoting
-     * table, and making it actual work to make them go out of sync again.
-     */
-    private static abstract class LegalCharacters {
-
-        // To quote http://www.w3.org/TR/REC-xml/ :
-        // Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] |
-        // [#x10000-#x10FFFF]
-        final boolean isLegal(int codepoint, boolean escapeLow, int stripCodePoint, boolean isAttribute) {
-            if (codepoint == stripCodePoint) {
-                return removeCodePoint();
-            } else if (codepoint < ' ') {
-                if (!escapeLow) {
-                    return true;
-                }
-                switch (codepoint) {
-                case 0x09:
-                case 0x0a:
-                case 0x0d:
-                    return true;
-                default:
-                    return ctrlEscapeCodePoint(codepoint);
-                }
-            } else if (codepoint >= 0x20 && codepoint <= 0xd7ff) {
-                switch (codepoint) {
-                case '&':
-                    return ampCodePoint();
-                case '<':
-                    return ltCodePoint();
-                case '>':
-                    return gtCodePoint();
-                case '"':
-                    return quotCodePoint(isAttribute);
-                default:
-                    return true;
-                }
-            } else if ((codepoint >= 0xe000 && codepoint <= 0xfffd)
-                    || (codepoint >= 0x10000 && codepoint <= 0x10ffff)) {
-                return true;
-            } else {
-                return filterCodePoint(codepoint);
-
-            }
-        }
-
-        private boolean quotCodePoint(boolean isAttribute) {
-            if (isAttribute) {
-                quoteQuot();
-                return false;
-            } else {
-                return true;
-            }
-        }
-
-        private boolean filterCodePoint(int codepoint) {
-            replace(codepoint);
-            return false;
-        }
-
-        private boolean gtCodePoint() {
-            quoteGt();
-            return false;
-        }
-
-        private boolean ltCodePoint() {
-            quoteLt();
-            return false;
-        }
-
-        private boolean ampCodePoint() {
-            quoteAmp();
-            return false;
-        }
-
-        private boolean ctrlEscapeCodePoint(int codepoint) {
-            ctrlEscape(codepoint);
-            return false;
-        }
-
-        private boolean removeCodePoint() {
-            remove();
-            return false;
-        }
-
-        protected abstract void quoteQuot();
-
-        protected abstract void quoteGt();
-
-        protected abstract void quoteLt();
-
-        protected abstract void quoteAmp();
-
-        protected abstract void remove();
-
-        protected abstract void ctrlEscape(int codepoint);
-
-        protected abstract void replace(int codepoint);
-    }
-
-    private static final class Quote extends LegalCharacters {
-
-        char[] lastQuoted;
-        private static final char[] EMPTY = new char[0];
-        private static final char[] REPLACEMENT_CHARACTER = "\ufffd".toCharArray();
-        private static final char[] AMP = "&amp;".toCharArray();
-        private static final char[] LT = "&lt;".toCharArray();
-        private static final char[] GT = "&gt;".toCharArray();
-        private static final char[] QUOT = "&quot;".toCharArray();
-
-        @Override
-        protected void remove() {
-            lastQuoted = EMPTY;
-        }
-
-        @Override
-        protected void replace(final int codepoint) {
-            lastQuoted = REPLACEMENT_CHARACTER;
-        }
-
-        @Override
-        protected void quoteQuot() {
-            lastQuoted = QUOT;
-        }
-
-        @Override
-        protected void quoteGt() {
-            lastQuoted = GT;
-        }
-
-        @Override
-        protected void quoteLt() {
-            lastQuoted = LT;
-        }
-
-        @Override
-        protected void quoteAmp() {
-            lastQuoted = AMP;
-        }
-
-        @Override
-        protected void ctrlEscape(final int codepoint) {
-            lastQuoted = REPLACEMENT_CHARACTER;
-        }
-    }
-
-    private static final class Scan extends LegalCharacters {
-
-        @Override
-        protected void quoteQuot() {
-        }
-
-        @Override
-        protected void quoteGt() {
-        }
-
-        @Override
-        protected void quoteLt() {
-        }
-
-        @Override
-        protected void quoteAmp() {
-        }
-
-        @Override
-        protected void remove() {
-        }
-
-        @Override
-        protected void ctrlEscape(final int codepoint) {
-        }
-
-        @Override
-        protected void replace(final int codepoint) {
-        }
-    }
-
     private static final Scan scanner = new Scan();
 
-    /**
-     * Replaces the characters that need to be escaped with their corresponding
-     * character entities.
-     *
-     * @param s1
-     *            String possibly containing characters that need to be escaped
-     *            in XML
-     *
-     * @return Returns the input string with special characters that need to be
-     *         escaped replaced by character entities.
-     */
-    public static String xmlEscape(String s1) {
-        return xmlEscape(s1, true, true, null, -1);
+    /** Replaces the characters that need to be escaped with their corresponding character entities. */
+    public static String xmlEscape(String string) {
+        return xmlEscape(string, true, true, null, -1);
     }
 
-    /**
-     * Replaces the characters that need to be escaped with their corresponding
-     * character entities.
-     *
-     * @param s1
-     *            String possibly containing characters that need to be escaped
-     *            in XML
-     * @param isAttribute
-     *            Is the input string to be used as an attribute?
-     *
-     * @return Returns the input string with special characters that need to be
-     *         escaped replaced by character entities
-     */
-    public static String xmlEscape(String s1, boolean isAttribute) {
-        return xmlEscape(s1, isAttribute, true, null, -1);
+    /** Replaces the characters that need to be escaped with their corresponding character entities. */
+    public static String xmlEscape(String string, boolean isAttribute) {
+        return xmlEscape(string, isAttribute, true, null, -1);
     }
 
-    /**
-     * Replaces the characters that need to be escaped with their corresponding
-     * character entities.
-     *
-     * @param s1
-     *            String possibly containing characters that need to be escaped
-     *            in XML
-     * @param isAttribute
-     *            Is the input string to be used as an attribute?
-     *
-     *
-     * @param stripCharacter
-     *            any occurrence of this character is removed from the string
-     *
-     * @return Returns the input string with special characters that need to be
-     *         escaped replaced by character entities
-     */
-    public static String xmlEscape(String s1, boolean isAttribute, char stripCharacter) {
-        return xmlEscape(s1, isAttribute, true, null, (int) stripCharacter);
+    /** Replaces the characters that need to be escaped with their corresponding character entities. */
+    public static String xmlEscape(String string, boolean isAttribute, char stripCharacter) {
+        return xmlEscape(string, isAttribute, true, null, (int) stripCharacter);
     }
 
-    /**
-     * Replaces the characters that need to be escaped with their corresponding
-     * character entities.
-     *
-     * @param s1
-     *            String possibly containing characters that need to be escaped
-     *            in XML
-     * @param isAttribute
-     *            Is the input string to be used as an attribute?
-     *
-     * @param escapeLowAscii
-     *            Should ascii characters below 32 be escaped as well
-     *
-     * @return Returns the input string with special characters that need to be
-     *         escaped replaced by character entities
-     */
-    public static String xmlEscape(String s1, boolean isAttribute, boolean escapeLowAscii) {
-        return xmlEscape(s1, isAttribute, escapeLowAscii, null, -1);
+    /** Replaces the characters that need to be escaped with their corresponding character entities. */
+    public static String xmlEscape(String string, boolean isAttribute, boolean escapeLowAscii) {
+        return xmlEscape(string, isAttribute, escapeLowAscii, null, -1);
     }
 
     /**
-     * Replaces the characters that need to be escaped with their corresponding
-     * character entities.
-     *
-     * @param s1
-     *            String possibly containing characters that need to be escaped
-     *            in XML
-     * @param isAttribute
-     *            Is the input string to be used as an attribute?
-     *
-     * @param escapeLowAscii
-     *            Should ascii characters below 32 be escaped as well
+     * Replaces the characters that need to be escaped with their corresponding character entities.
      *
-     * @param stripCharacter
-     *            any occurrence of this character is removed from the string
-     *
-     * @return Returns the input string with special characters that need to be
-     *         escaped replaced by character entities
+     * @param string the string possibly containing characters that need to be escaped in XML
+     * @param isAttribute whether the input string to be used as an attribute
+     * @param escapeLowAscii whether ascii characters below 32 should be escaped as well
+     * @param stripCharacter any occurrence of this character is removed from the string
+     * @return the input string with special characters that need to be escaped replaced by character entities
      */
-    public static String xmlEscape(String s1, boolean isAttribute, boolean escapeLowAscii, char stripCharacter) {
-        return xmlEscape(s1, isAttribute, escapeLowAscii, null, (int) stripCharacter);
+    public static String xmlEscape(String string, boolean isAttribute, boolean escapeLowAscii, char stripCharacter) {
+        return xmlEscape(string, isAttribute, escapeLowAscii, null, (int) stripCharacter);
     }
 
     /**
@@ -315,7 +75,6 @@ public class XML {
      * <li>double quotes (&quot;) if isAttribute is <code>true</code>
      * </ul>
      * with character entities.
-     *
      */
     public static String xmlEscape(String string, boolean isAttribute, StringBuilder buffer) {
         return xmlEscape(string, isAttribute, true, buffer, -1);
@@ -332,7 +91,6 @@ public class XML {
      * <li>double quotes (&quot;) if isAttribute is <code>true</code>
      * </ul>
      * with character entities.
-     *
      */
     public static String xmlEscape(String string, boolean isAttribute, boolean escapeLowAscii, StringBuilder buffer) {
         return xmlEscape(string, isAttribute, escapeLowAscii, buffer, -1);
@@ -438,15 +196,13 @@ public class XML {
         }
     }
 
-    /**
-     * Returns the Document of the string XML payload
-     */
+    /** Returns the Document of the string XML payload. */
     public static Document getDocument(String xmlString) {
         return getDocument(new StringReader(xmlString));
     }
 
     /**
-     * Creates a new XML DocumentBuilder
+     * Creates a new XML DocumentBuilder.
      *
      * @return a DocumentBuilder
      * @throws RuntimeException if we fail to create one
@@ -456,7 +212,7 @@ public class XML {
     }
 
     /**
-     * Creates a new XML DocumentBuilder
+     * Creates a new XML DocumentBuilder.
      *
      * @param implementation which jaxp implementation should be used
      * @param classLoader which class loader should be used when getting a new DocumentBuilder
@@ -468,7 +224,7 @@ public class XML {
     }
 
         /**
-         * Creates a new XML DocumentBuilder
+         * Creates a new XML DocumentBuilder.
          *
          * @return a DocumentBuilder
          * @throws RuntimeException if we fail to create one
@@ -479,7 +235,7 @@ public class XML {
     }
 
     /**
-     * Creates a new XML DocumentBuilder
+     * Creates a new XML DocumentBuilder.
      *
      * @param implementation which jaxp implementation should be used
      * @param classLoader which class loader should be used when getting a new DocumentBuilder
@@ -508,7 +264,7 @@ public class XML {
     }
 
     /**
-     * Returns the child Element objects from a w3c dom spec
+     * Returns the child Element objects from a w3c dom spec.
      *
      * @return List of elements. Empty list (never null) if none found or if the given element is null
      */
@@ -554,18 +310,21 @@ public class XML {
         return ret;
     }
 
+    /** Returns the given attribute name from element, or empty if the element does not have it. */
+    public static Optional<String> attribute(String name, Element element) {
+        if ( ! element.hasAttribute(name)) return Optional.empty();
+        return Optional.of(element.getAttribute(name));
+    }
+
     /**
      * Gets the string contents of the given Element. Returns "", never null if
      * the element is null, or has no content
      */
     public static String getValue(Element e) {
-        if (e == null) {
-            return "";
-        }
+        if (e == null) return "";
         Node child = e.getFirstChild();
-        if (child == null) {
-            return "";
-        }
+        if (child == null) return "";
+        if (child.getNodeValue() == null) return "";
         return child.getNodeValue();
     }
 
@@ -575,14 +334,11 @@ public class XML {
     }
 
     /**
-     * Returns the path to the given xml node, where each node name is separated
-     * by the given separator string.
+     * Returns the path to the given xml node, where each node name is separated by the given separator string.
      *
-     * @param n
-     *            The xml node to find path to
-     * @param sep
-     *            The separator string
-     * @return The path to the xml node as a String
+     * @param n the xml node to find path to
+     * @param sep the separator string
+     * @return the path to the xml node as a String
      */
     public static String getNodePath(Node n, String sep) {
         if (n == null) {
@@ -657,8 +413,7 @@ public class XML {
      * 1.1 (Second Edition)</a>. This does not check against reserved names, it
      * only checks the set of characters used.
      *
-     * @param possibleName
-     *            a possibly valid XML name
+     * @param possibleName a possibly valid XML name
      * @return true if the name may be used as an XML tag or attribute name
      */
     public static boolean isName(CharSequence possibleName) {
@@ -683,4 +438,181 @@ public class XML {
         return valid;
     }
 
+    /**
+     * The point of this weird class and the jumble of abstract methods is
+     * linking the scan for characters that must be quoted into the quoting
+     * table, and making it actual work to make them go out of sync again.
+     */
+    private static abstract class LegalCharacters {
+        // To quote http://www.w3.org/TR/REC-xml/ :
+        // Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] |
+        // [#x10000-#x10FFFF]
+        final boolean isLegal(int codepoint, boolean escapeLow, int stripCodePoint, boolean isAttribute) {
+            if (codepoint == stripCodePoint) {
+                return removeCodePoint();
+            } else if (codepoint < ' ') {
+                if (!escapeLow) {
+                    return true;
+                }
+                switch (codepoint) {
+                    case 0x09:
+                    case 0x0a:
+                    case 0x0d:
+                        return true;
+                    default:
+                        return ctrlEscapeCodePoint(codepoint);
+                }
+            } else if (codepoint >= 0x20 && codepoint <= 0xd7ff) {
+                switch (codepoint) {
+                    case '&':
+                        return ampCodePoint();
+                    case '<':
+                        return ltCodePoint();
+                    case '>':
+                        return gtCodePoint();
+                    case '"':
+                        return quotCodePoint(isAttribute);
+                    default:
+                        return true;
+                }
+            } else if ((codepoint >= 0xe000 && codepoint <= 0xfffd)
+                       || (codepoint >= 0x10000 && codepoint <= 0x10ffff)) {
+                return true;
+            } else {
+                return filterCodePoint(codepoint);
+
+            }
+        }
+
+        private boolean quotCodePoint(boolean isAttribute) {
+            if (isAttribute) {
+                quoteQuot();
+                return false;
+            } else {
+                return true;
+            }
+        }
+
+        private boolean filterCodePoint(int codepoint) {
+            replace(codepoint);
+            return false;
+        }
+
+        private boolean gtCodePoint() {
+            quoteGt();
+            return false;
+        }
+
+        private boolean ltCodePoint() {
+            quoteLt();
+            return false;
+        }
+
+        private boolean ampCodePoint() {
+            quoteAmp();
+            return false;
+        }
+
+        private boolean ctrlEscapeCodePoint(int codepoint) {
+            ctrlEscape(codepoint);
+            return false;
+        }
+
+        private boolean removeCodePoint() {
+            remove();
+            return false;
+        }
+
+        protected abstract void quoteQuot();
+
+        protected abstract void quoteGt();
+
+        protected abstract void quoteLt();
+
+        protected abstract void quoteAmp();
+
+        protected abstract void remove();
+
+        protected abstract void ctrlEscape(int codepoint);
+
+        protected abstract void replace(int codepoint);
+    }
+
+    private static final class Quote extends LegalCharacters {
+
+        char[] lastQuoted;
+        private static final char[] EMPTY = new char[0];
+        private static final char[] REPLACEMENT_CHARACTER = "\ufffd".toCharArray();
+        private static final char[] AMP = "&amp;".toCharArray();
+        private static final char[] LT = "&lt;".toCharArray();
+        private static final char[] GT = "&gt;".toCharArray();
+        private static final char[] QUOT = "&quot;".toCharArray();
+
+        @Override
+        protected void remove() {
+            lastQuoted = EMPTY;
+        }
+
+        @Override
+        protected void replace(final int codepoint) {
+            lastQuoted = REPLACEMENT_CHARACTER;
+        }
+
+        @Override
+        protected void quoteQuot() {
+            lastQuoted = QUOT;
+        }
+
+        @Override
+        protected void quoteGt() {
+            lastQuoted = GT;
+        }
+
+        @Override
+        protected void quoteLt() {
+            lastQuoted = LT;
+        }
+
+        @Override
+        protected void quoteAmp() {
+            lastQuoted = AMP;
+        }
+
+        @Override
+        protected void ctrlEscape(final int codepoint) {
+            lastQuoted = REPLACEMENT_CHARACTER;
+        }
+    }
+
+    private static final class Scan extends LegalCharacters {
+
+        @Override
+        protected void quoteQuot() {
+        }
+
+        @Override
+        protected void quoteGt() {
+        }
+
+        @Override
+        protected void quoteLt() {
+        }
+
+        @Override
+        protected void quoteAmp() {
+        }
+
+        @Override
+        protected void remove() {
+        }
+
+        @Override
+        protected void ctrlEscape(final int codepoint) {
+        }
+
+        @Override
+        protected void replace(final int codepoint) {
+        }
+    }
+
 }