Repo created

libs/coding/parse_xml.hpp

@@ -0,0 +1,84 @@
+#pragma once
+
+#include "coding/internal/xmlparser.hpp"
+
+#include "base/assert.hpp"
+#include "base/exception.hpp"
+
+#include <algorithm>
+#include <cstdint>
+#include <exception>
+
+DECLARE_EXCEPTION(XmlParseError, RootException);
+
+template <typename Sequence, typename XMLDispatcher>
+class XMLSequenceParser
+{
+public:
+  XMLSequenceParser(Sequence & source, XMLDispatcher & dispatcher, bool useCharData = false)
+    : m_res(0)
+    , m_numRead(0)
+    , m_source(source)
+    , m_parser(dispatcher, useCharData)
+  {}
+
+  bool Read()
+  {
+    char * buffer = static_cast<char *>(m_parser.GetBuffer(kBufferSize));
+    ASSERT(buffer, ());
+
+    m_numRead = m_source.Read(buffer, kBufferSize);
+    if (m_numRead == 0)
+      return false;
+
+    if (m_parser.ParseBuffer(static_cast<uint32_t>(m_numRead), false) == XML_STATUS_ERROR)
+      MYTHROW(XmlParseError, (m_parser.GetErrorMessage()));
+
+    m_res += m_numRead;
+    return m_numRead == kBufferSize;
+  }
+
+private:
+  uint32_t static constexpr kBufferSize = 16 * 1024;
+
+  uint64_t m_res = 0;
+  uint64_t m_numRead = 0;
+  Sequence & m_source;
+  XmlParser<XMLDispatcher> m_parser;
+};
+
+template <class Source>
+class SequenceAdapter
+{
+public:
+  SequenceAdapter(Source & source) : m_source(source) {}
+
+  uint64_t Read(void * p, uint64_t size)
+  {
+    size_t const correctSize = static_cast<size_t>(std::min(size, m_source.Size()));
+    m_source.Read(p, correctSize);
+    return correctSize;
+  }
+
+private:
+  Source & m_source;
+};
+
+template <typename XMLDispatcher, typename Source>
+bool ParseXML(Source & source, XMLDispatcher & dispatcher, bool useCharData = false)
+{
+  SequenceAdapter<Source> adapter(source);
+  XMLSequenceParser<decltype(adapter), XMLDispatcher> parser(adapter, dispatcher, useCharData);
+  try
+  {
+    while (parser.Read()) /* empty */
+      ;
+  }
+  catch (std::exception const & e)
+  {
+    LOG(LWARNING, (e.what()));
+    return false;
+  }
+
+  return true;
+}