1 files changed, 77 insertions, 0 deletions
diff --git a/internal/xmpmeta/xml/utils.cc b/internal/xmpmeta/xml/utils.cc
new file mode 100644
index 0000000..87bf0b1
--- /dev/null
+++ b/internal/xmpmeta/xml/utils.cc
@@ -0,0 +1,77 @@
+#include "xmpmeta/xml/utils.h"
+
+#include "android-base/logging.h"
+#include "base/port.h"
+#include "xmpmeta/xml/const.h"
+#include "xmpmeta/xml/search.h"
+
+namespace photos_editing_formats {
+namespace xml {
+
+xmlNodePtr GetFirstDescriptionElement(const xmlDocPtr parent) {
+  return DepthFirstSearch(parent, XmlConst::RdfDescription());
+}
+
+xmlNodePtr GetFirstSeqElement(xmlDocPtr parent) {
+  // DepthFirstSearch will perform the null check.
+  return DepthFirstSearch(parent, XmlConst::RdfSeq());
+}
+
+// Returns the first rdf:Seq element found in the given node.
+xmlNodePtr GetFirstSeqElement(xmlNodePtr parent) {
+  // DepthFirstSearch will perform the null check.
+  return DepthFirstSearch(parent, XmlConst::RdfSeq());
+}
+
+// Returns the ith (zero-indexed) element in the given node.
+// {@code parent} is an rdf:Seq node.
+xmlNodePtr GetElementAt(xmlNodePtr node, int index) {
+  if (node == nullptr || index < 0) {
+    LOG(ERROR) << "Node was null or index was negative";
+    return nullptr;
+  }
+  const string node_name = FromXmlChar(node->name);
+  if (strcmp(node_name.c_str(), XmlConst::RdfSeq())) {
+    LOG(ERROR) << "Node is not an rdf:Seq node, was " << node_name;
+    return nullptr;
+  }
+  int i = 0;
+  for (xmlNodePtr child = node->children; child != nullptr && i <= index;
+       child = child->next) {
+    if (strcmp(FromXmlChar(child->name), XmlConst::RdfLi())) {
+      // This is not an rdf:li node. This can occur because the node's content
+      // is also treated as a node, and these should be ignored.
+      continue;
+    }
+    if (i == index) {
+      return child;
+    }
+    i++;
+  }
+  return nullptr;
+}
+
+const string GetLiNodeContent(xmlNodePtr node) {
+  string value;
+  if (node == nullptr || strcmp(FromXmlChar(node->name), XmlConst::RdfLi())) {
+    LOG(ERROR) << "Node is null or is not an rdf:li node";
+    return value;
+  }
+  xmlChar* node_content = xmlNodeGetContent(node);
+  value = FromXmlChar(node_content);
+  free(node_content);
+  return value;
+}
+
+const string XmlDocToString(const xmlDocPtr doc) {
+  xmlChar* xml_doc_contents;
+  int doc_size = 0;
+  xmlDocDumpFormatMemoryEnc(doc, &xml_doc_contents, &doc_size,
+                            XmlConst::EncodingStr(), 1);
+  const string xml_doc_string(FromXmlChar(xml_doc_contents));
+  xmlFree(xml_doc_contents);
+  return xml_doc_string;
+}
+
+}  // namespace xml
+}  // namespace photos_editing_formats